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Posts Tagged ‘Cancer – General’

Novel Mechanisms of Resistance to Novel Agents

 

Curators: Larry H. Berstein, M.D. FACP & Stephen J. Williams, Ph.D.

For most of the history of chemotherapy drug development, predicting the possible mechanisms of drug resistance that ensued could be surmised from the drug’s pharmacologic mechanism of action. In other words, a tumor would develop resistance merely by altering the pathways/systems which the drug relied on for mechanism of action. For example, as elucidated in later chapters in this book, most cytotoxic chemotherapies like cisplatin and cyclophosphamide were developed to bind DNA and disrupt the cycling cell, thereby resulting in cell cycle arrest and eventually cell death or resulting in such a degree of genotoxicity which would result in great amount of DNA fragmentation. These DNA-damaging agents efficacy was shown to be reliant on their ability to form DNA adducts and lesions. Therefore increasing DNA repair could result in a tumor cell becoming resistant to these drugs. In addition, if drug concentration was merely decreased in these cells, by an enhanced drug efflux as seen with the ABC transporters, then there would be less drug available for these DNA adducts to be generated. A plethora of literature has been generated on this particular topic.

However in the era of chemotherapies developed against targets only expressed in tumor cells (such as Gleevec against the Bcr-Abl fusion protein in chronic myeloid leukemia), this paradigm had changed as clinical cases of resistance had rapidly developed soon after the advent of these compounds and new paradigms of resistance mechanisms were discovered.

speed of imitinib resistance

Imatinib resistance can be seen quickly after initiation of therapy

mellobcrablresistamplification

Speed of imatinib resistance a result of rapid gene amplification of BCR/ABL target, thereby decreasing imatinib efficacy

 

 

 

 

 

 

 

 

 

 

Although there are many other new mechanisms of resistance to personalized medicine agents (which are discussed later in the chapter) this post is a curation of cellular changes which are not commonly discussed in reviews of chemoresistance and separated in three main categories:

Cellular Diversity and Adaptation

Identifying Cancers and Resistance

Cancer Drug-Resistance Mechanism

p53 tumor drug resistance gene target

Variability of Gene Expression and Drug Resistance

 

Expression of microRNAs and alterations in RNA resulting in chemo-resistance

Drug-resistance Mechanism in Tumor Cells

Overexpression of miR-200c induces chemoresistance in esophageal cancers mediated through activation of the Akt signaling pathway

 

The miRNA–drug resistance connection: a new era of personalized medicine using noncoding RNA begins

 

Gene Duplication of Therapeutic Target

 

The advent of Gleevec (imatinib) had issued in a new era of chemotherapy, a personalized medicine approach by determining the and a lifesaver to chronic myeloid leukemia (CML) patients whose tumors displayed expression of the Bcr-Abl fusion gene. However it was not long before clinical resistance was seen to this therapy and, it was shown amplification of the drug target can lead to tumor outgrowth despite adequate drug exposure. le Coutre, Weisberg and Mahon23, 24, 25 all independently generated imatinib-resistant clones through serial passage of the cells in imatinib-containing media and demonstrated elevated Abl kinase activity due to a genetic amplification of the Bcr–Abl sequence. However, all of these samples were derived in vitro and may not represent a true mode of clinical resistance. Nevertheless, Gorre et al.26 obtained specimens, directly patients demonstrating imatinib resistance, and using fluorescence in situ hybridization analysis, genetic duplication of the Bcr–Abl gene was identified as one possible source of the resistance. Additional sporadic examples of amplification of the Bcr–Abl sequence have been clinically described, but the majority of patients presenting with either primary or secondary imatinib resistance fail to clinically demonstrate Abl amplification as a primary mode of treatment failure.

This is seen in the following papers:

Clinical resistance to STI-571 cancer therapy caused by BCR-ABL gene mutation or amplification.Gorre ME, Mohammed M, Ellwood K, Hsu N, Paquette R, Rao PN, Sawyers CL. Science. 2001 Aug 3;293(5531):876-80. Epub 2001 Jun 21.

and in another original paper by le Coutre et. al.

Induction of resistance to the Abelson inhibitor STI571 in human leukemic cells through gene amplification. le Coutre P1, Tassi E, Varella-Garcia M, Barni R, Mologni L, Cabrita G, Marchesi E, Supino R, Gambacorti-Passerini C. Blood. 2000 Mar 1;95(5):1758-66

The 2-phenylaminopyrimidine derivative STI571 has been shown to selectively inhibit the tyrosine kinase domain of the oncogenic bcr/abl fusion protein. The activity of this inhibitor has been demonstrated so far both in vitro with bcr/abl expressing cells derived from leukemic patients, and in vivo on nude mice inoculated with bcr/abl positive cells. Yet, no information is available on whether leukemic cells can develop resistance to bcr/abl inhibition. The human bcr/abl expressing cell line LAMA84 was cultured with increasing concentrations of STI571. After approximately 6 months of culture, a new cell line was obtained and named LAMA84R. This newly selected cell line showed an IC50 for the STI571 (1.0 microM) 10-fold higher than the IC50 (0.1 microM) of the parental sensitive cell line. Treatment with STI571 was shown to increase both the early and late apoptotic fraction in LAMA84 but not in LAMA84R. The induction of apoptosis in LAMA84 was associated with the activation of caspase 3-like activity, which did not develop in the resistant LAMA84R cell line. LAMA84R cells showed increased levels of bcr/abl protein and mRNA when compared to LAMA84 cells. FISH analysis with BCR- and ABL-specific probes in LAMA84R cells revealed the presence of a marker chromosome containing approximately 13 to 14 copies of the BCR/ABL gene. Thus, overexpression of the Bcr/Abl protein mediated through gene amplification is associated with and probably determines resistance of human leukemic cells to STI571 in vitro. (Blood. 2000;95:1758-1766)

This is actually the opposite case with other personalized therapies like the EGFR inhibitor gefinitib where actually the AMPLIFICATION of the therapeutic target EGFR is correlated with better response to drug in

Molecular mechanisms of epidermal growth factor receptor (EGFR) activation and response to gefitinib and other EGFR-targeting drugs.Ono M, Kuwano M. Clin Cancer Res. 2006 Dec 15;12(24):7242-51. Review.

Abstract

The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases, including EGFR, HER2/erbB2, and HER3/erbB3, is an attractive target for antitumor strategies. Aberrant EGFR signaling is correlated with progression of various malignancies, and somatic tyrosine kinase domain mutations in the EGFR gene have been discovered in patients with non-small cell lung cancer responding to EGFR-targeting small molecular agents, such as gefitinib and erlotinib. EGFR overexpression is thought to be the principal mechanism of activation in various malignant tumors. Moreover, an increased EGFR copy number is associated with improved survival in non-small cell lung cancer patients, suggesting that increased expression of mutant and/or wild-type EGFR molecules could be molecular determinants of responses to gefitinib. However, as EGFR mutations and/or gene gains are not observed in all patients who respond partially to treatment, alternative mechanisms might confer sensitivity to EGFR-targeting agents. Preclinical studies showed that sensitivity to EGFR tyrosine kinase inhibitors depends on how closely cell survival and growth signalings are coupled with EGFR, and also with HER2 and HER3, in each cancer. This review also describes a possible association between EGFR phosphorylation and drug sensitivity in cancer cells, as well as discussing the antiangiogenic effect of gefitinib in association with EGFR activation and phosphatidylinositol 3-kinase/Akt activation in vascular endothelial cells.

 

Mutant Variants of Therapeutic Target

 

resistant subclones in tissue samples and Tyrosine Kinase tumor activity

 

Mitochondrial Isocitrate Dehydrogenase and Variants

Mutational Landscape of Rare Childhood Brain Cancer: Analysis of 60 Intercranial Germ Cell Tumor Cases using NGS, SNP and Expression Array Analysis – Signaling Pathways KIT/RAS are affected by mutations in IGCTs

 

AND seen with the ALK inhibitors as well (as seen in the following papers

Acquisition of cancer stem cell-like properties in non-small cell lung cancer with acquired resistance to afatinib.

Hashida S, Yamamoto H, Shien K, Miyoshi Y, Ohtsuka T, Suzawa K, Watanabe M, Maki Y, Soh J, Asano H, Tsukuda K, Miyoshi S, Toyooka S. Cancer Sci. 2015 Oct;106(10):1377-84. doi: 10.1111/cas.12749. Epub 2015 Sep 30.

In vivo imaging models of bone and brain metastases and pleural carcinomatosis with a novel human EML4-ALK lung cancer cell line.

Nanjo S, Nakagawa T, Takeuchi S, Kita K, Fukuda K, Nakada M, Uehara H, Nishihara H, Hara E, Uramoto H, Tanaka F, Yano S. Cancer Sci. 2015 Mar;106(3):244-52. doi: 10.1111/cas.12600. Epub 2015 Feb 17.

Identification of a novel HIP1-ALK fusion variant in Non-Small-Cell Lung Cancer (NSCLC) and discovery of ALK I1171 (I1171N/S) mutations in two ALK-rearranged NSCLC patients with resistance to Alectinib. Ou SH, Klempner SJ, Greenbowe JR, Azada M, Schrock AB, Ali SM, Ross JS, Stephens PJ, Miller VA.J Thorac Oncol. 2014 Dec;9(12):1821-5

Reports of chemoresistance due to variants have also been seen with the BRAF inhibitors like vemurafenib and dabrafenib:

The RAC1 P29S hotspot mutation in melanoma confers resistance to pharmacological inhibition of RAF.

Watson IR, Li L, Cabeceiras PK, Mahdavi M, Gutschner T, Genovese G, Wang G, Fang Z, Tepper JM, Stemke-Hale K, Tsai KY, Davies MA, Mills GB, Chin L.Cancer Res. 2014 Sep 1;74(17):4845-52. doi: 10.1158/0008-5472.CAN-14-1232-T. Epub 2014 Jul 23

 

 

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Guanosine triphosphate (GTP) cancer link

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Energy-Sensing Enzyme May Serve as Cancer Therapy Target

http://www.genengnews.com/gen-news-highlights/energy-sensing-enzyme-may-serve-as-cancer-therapy-target/81252200/

 

A scientific team led by a University of Cincinnati (UC) cancer researcher has shown that a specific enzyme is responsible for sensing the available supply of guanosine triphosphate (GTP) that can fuel the uncontrolled growth of cancer cells. The research underscores the enzyme’s potential to become a therapeutic target for future cancer drugs, according to the investigators.

Atsuo Sasaki, Ph.D., assistant professor in the division of hematology oncology at the UC College of Medicine, Toshiya Senda, Ph.D., professor at the High Energy Accelerator Research Organization in Tsukuba, Japan, and colleagues showed that PI5P4Kβ (phosphatidylinositol-5-phosphate 4-kinase-β) acts like the arrow on a fuel gauge. The enzyme senses and communicates via a second messenger the amount of GTP fuel that is available to a cell at any given time. Until now, the molecular identity of a GTP sensor has remained unknown.

“Energy sensing is vital to the successful proliferation of cancer cells,” says Dr. Sasaki. “A large amount of GTP is required in rapidly dividing cells, and cells need to know that the fuel is available to them. If we can interfere with the ability of PI5P4Kβ to sense fuel availability and communicate that information, we may be able to slow or halt the growth of cancers, including the aggressive brain cancer glioblastoma multiforme and cancers that have metastasized to the brain.”

The study (“The Lipid Kinase PI5P4Kβ Is an Intracellular GTP Sensor for Metabolism and Tumorigenesis”), published in Molecular Cell, is Dr. Sasaki’s first to address PI5P4Kβ as a molecular sensor of GTP concentration. Initially, he and his team reportedly faced skepticism regarding the existence of GTP energy-sensing.

GTP is one of two energy molecules used by cells. The other is adenosine triphosphate.  ATP handles the bulk of a cell’s energy requirements, while GTP is required for protein synthesis and is a signaling molecule that helps direct processes within the cell. When GTP levels are increased and utilized as fuel by cancer cells, its ability to perform its primary goals is compromised.

Dr. Sasaki and his team identified PI5P4Kβ as a GTP sensor by demonstrating, in a laboratory setting its ability to bind to GTP and by showing, at the atomic level by X-ray structural analysis, the molecular mechanism by which it recognizes GTP. They then designed PI5P4Kβ mutant cells that were unable to sense GTP concentration and, as a result, impaired the ability of PI5P4Kβ to promote tumor growth.

His next step is to use both pharmacological and molecular approaches that target PI5P4Kβ in a cell culture and in animal tumor models.

“By unveiling PI5P4Kβ’s role as a GTP sensor, we now have a potential new therapeutic target for patients,” explains Dr. Sasaki. “If we can find drugs that stop PI5P4Kβ from acting as the fuel indicator, we could get these aggressive and tragic cancers into energy-depleted status.”

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Serpins: A Review

Reporter: Stephen J. Williams, Ph.D.

Update of the human and mouse SERPIN gene superfamily

Abstract

The serpin family comprises a structurally similar, yet functionally diverse, set of proteins. Named originally for their function as serine proteinase inhibitors, many of its members are not inhibitors but rather chaperones, involved in storage, transport, and other roles. Serpins are found in genomes of all kingdoms, with 36 human protein-coding genes and five pseudogenes. The mouse has 60 Serpin functional genes, many of which are orthologous to human SERPIN genes and some of which have expanded into multiple paralogous genes. Serpins are found in tissues throughout the body; whereas most are extracellular, there is a class of intracellular serpins. Serpins appear to have roles in inflammation, immune function, tumorigenesis, blood clotting, dementia, and cancer metastasis. Further characterization of these proteins will likely reveal potential biomarkers and therapeutic targets for disease.

Keywords: Serpins, Serine protease inhibitor, Chaperone, Blood clotting, Thrombolysis, Complement, Cell death, Metastatic cancer

Introduction

Serpins represent the largest and most functionally diverse family of protease inhibitors. The name serpin originates from the first described function of this family, viz., serine proteinase inhibitors. In their native state, serpins exist as monomeric proteins. Most serpin family members inhibit serine proteinases of the chymotrypsin family [1], thereby inhibiting proteolytic cascades. However, some serpins exhibit functions unrelated to inhibition of catalytic activity, such as hormone transport and other mechanisms.

Approximately 1,500 serpin sequences have been identified; they are found in the genomes of all five kingdoms [2]. There are 36 identified human putatively functional protein-coding genes [3]. The serpin superfamily is divided into groups called clades according to their sequence similarity. Clades are classified as A–P, with clades A–I representing human serpins [4].

Serpins have well-conserved secondary structures with an exposed reactive center loop (RCL) (Figure 1), which interacts with the protease active site to inhibit protease activity [5]. The ability for serpins to undergo conformational change is crucial for their function, in which serpins act via a suicide substrate inhibitory mechanism [2,4]. Although most serpins selectively inhibit serine proteases, some inhibit cysteine proteases, such as caspases and cathespins; others perform hormone transport and blood pressure regulation [4]. Serpins play important physiological roles in hormone transport, corticosteroid binding, coagulation, and blood pressure regulation.

Figure 1

Native SERPINA1. Native SERPINA1 with labeled structural elements: β sheet a and reactive center loop (RCL); α helices in red, β sheets in turquoise, turns in green. (Adapted from PDB 1HP7).

Serpin nomenclature

Initially named for tissue location or function (Table 1), a nomenclature committee convened in 1999 with the goal of standardizing serpin gene nomenclature [4]. ‘SERPIN’ was designated as the gene symbol for humans and other species because it is well known and used in the literature and as a keyword [4]. Serpins were not named for activity or function due to the diversity of member structure and tissue distribution. In 2005, proteinase in human gene names was replaced with the term peptidase; however, ‘serpin’ remains the stem because the name was designated prior to this change. The current classification of serpins involves division into clades that are based on phylogenetic relationships (Figure 2). There are 16 clades labeled A–P. Human serpins are represented in the first nine clades (i.e., A–I), with a variety of members being in each clade. Clades are phylogenetically unique and it is important to recognize that no relationships between the clade letters are implied by their order [4]. Some serpins are classified as orphans because they do not group with any other clade. It is likely that they will form clades as new serpins are identified. An example to help illustrate the nomenclature would be α-1-antitrypsin. This was assigned to the first clade, giving it the symbol SERPINA1 with the ‘A’ referencing the clade and the ‘1’ referencing the gene number within the clade [4].

Table 1

SERPIN aliases and function

Figure 2

SERPIN phylogenetic tree. Phylogenetic tree of human and mouse serpin proteins. Protein sequences were aligned using TCOFFEE and analysed using neighbour-joining methods with 10,000 bootstrap replicates in the Phylip package.

Structure function

Serpins have a metastable structure that is required for their function. It consists of a highly conserved secondary structure with three β-sheets (A, B, and C), nine α-helices and a RCL (Figure 1), which serve as bait for target proteases [4,6]. Well-conserved throughout the serpin family, the tertiary structure of scaffold allows for a conformational change critical to protease inhibitor activity [4]. In their native state, serpins exist as monomeric proteins. A serpin molecule consists of a single 330- to 500-amino acid polypeptide chain that has conserved secondary helices and sheets. To inhibit proteolytic activity, the serpin acts as a suicide substrate for the protease [4]. This is accomplished by the RCL of the serpin interacting with the protease’s active site [6].

Serpins can exist in several forms, viz., active, latent, cleaved, delta, and polymeric. Each form is defined by the RCL, which is the moiety required for inhibitory activity. The active form (or the native state) has an exposed RCL that allows it to interact with the protease. The RCL forms an exposed extension located above the molecule. Following proteolysis, the amino acid terminus of the RCL inserts into the A β sheet forming a fourth strand. This process is called the ‘stressed (S) to relaxed (R) transition’ [3] used to inhibit proteases, resulting in the cleaved form. The cleaved form is necessary for inhibition of proteases resulting in an irreversible covalent complex with the target protease thus inactivating both the serpin and the target. Some serpins bind cofactors and/or glycosaminoglycans to maximize protease inhibition, which can vastly increase inhibitory potential [7].

The native form of serpins has low thermal stability indicating that it is not the most stable conformation; rather, native serpins are metastable. However, not all serpins undergo this transition. Serpins can transition to the latent form from the active form and back to the active form from the latent form. The latent form does not possess inhibitory activity but it can convert to the active form through denaturation and refolding [4]. Consequently, it can be considered a control mechanism in regulating homeostasis for certain serpins [3]. Alternatively, the latent state caused by a mutation can be pathological [3].

The delta form is an intermediate conformation between latent and native state where the RCL inserts into the A β sheet and one of the helices unwinds and completes hydrogen bonding of the β sheet [3]. Little is known about the function of this conformation; however, it is likely that this favors polymeric or latent conformation transition rather than native. The polymeric form has a loop sheet mechanism whereby the RCL that would be inserted into the same serpin is instead inserted into the A β sheet of another serpin forming a long chain of these molecules [3]. However, this mechanism of polymerization has recently been challenged in favor of that of a domain-swapping model [8]. Serpins are unique in that their native state (active form) is not the most kinetically stable; rather, it is ‘metastable’. By incorporating the RCL into their A β sheet, either by cleavage for inhibition of target protease or spontaneous latency, they become more stable [9]. For an excellent minireview on kinetics of serpins, see Silverman et al. [4].

Evolution

Whereas serpins have highly conserved secondary and tertiary structures upon which they are grouped, they often share little amino acid sequence similarity. They do, however, share a highly conserved core, especially in the shutter domain including Ser56 and Ser53 [10], which is thought to be critical in determining tertiary structure and conformational flexibility.

Due to the numerous, yet distinct, processes regulated by serpins and their widespread functions, serpins offer a unique perspective for protein evolution. Members of the serpin family tend to group phylogenetically by species rather than by function. Therefore, evolution of the serpin family was likely driven by speciation to fill their physiological roles rather than by coevolution with the serine proteases (which group by function) [10]. Numerous serpin genes are also found in clusters on the same chromosomes, reflecting earlier gene-duplication events and potentially indicating a common precursor [11,12]. Interestingly, these genes are functionally divergent, despite their chromosomal proximity [7]. In addition, serpins have distinct patterns of introns and exons. These patterns may contain information regarding phylogenetic signals and be evolutionarily related based on relative intron positioning [13,14].

The distribution of serpins in eukaryotes suggests that they arose early in eukaryotic evolution [1]. Extensive gene clustering indicates that numerous serpins in close proximity on the same chromosome may have arisen as a result of duplications from a common precursor [12]; however, the evolution of these proximal genes gave way to vastly divergent functions.

Intracellular serpins of clade B are ancestral to most extracellular serpins [15,16] and each inhibitory serpin contains a highly conserved hinge region [16] within the RCL. Clade F serpins specifically share ancestry with a sea lamprey serpin. Clade P is specific to plant serpins which form a discrete clade. At the time of divergence between Viridiplantae and fungi/Metazoa groups, there was likely only one serpin gene [16]; however, the ancestral homolog from prokaryote or fungi has not yet been identified [16].

There are eight human serpin pseudogenes listed in Table 2. SERPINA15P has been named in succession for the A clade with the parent gene SERPINA6 according to Ensembl and SERPINE2 is the parent gene for SERPINE4P, again named in sequence of the E clade. There are ten mouse pseudogenes listed (Table 3) which remain uncharacterized.

Table 2

Human SERPIN genes

Table 3

Mouse Serpin genes

Methods

Protein sequences for human serpins were accessed from Uniprot through the HUGO Gene Nomenclature Committee website (http://www.genenames.org). Sequences were retrieved from the National Center for Biotechnology Information (NCBI) gene database (http://www.ncbi.nlm.nih.gov/gene) referenced through the HUGO Gene Nomenclature Committee website (http://www.genenames.org) for humans and MGI website (http://www.informatics.jax.org) for mouse. All sequences were aligned using the most accurate settings of T-Coffee (http://tcoffee.crg.cat/) and phylogenetic trees were constructed using neighbor-joining methods with 1000 replicate bootstrap in PHYLIP 3.69 (http://evolution.genetics.washington.edu/phylip.html) (Figure 2). Expression data were determined using Genecards (http://www.genecards.org) and alternative name information was determined using HGNC (http://www.genenames.org) or MGI (http://www.informatics.jax.org).

Human and mouse serpin isoforms

Clade A

Clade A serpins are classified as antitrypsin-like, extracellular proteins. They are the largest of the eight clades of extracellular serpins. The SERPINA clade has eleven human genes (1, 3–12) and two pseudogenes.

SERPINA1 is an inhibitory serpin formerly known as antitrypsin. It plays a role in the inhibition of neutrophil elastase [3,17].

SERPINA2 was initially classified as a pseudogene; however, recent evidence indicates that it produces an active transcript that encodes a protein located in the endoplasmic reticulum [18]. A study that sequenced SERPINA2 genes across multiple ethnic groups indicated that in addition to active SERPINA2 protein, there is a haplotype characterized by a partial deletion which has patterns suggestive of positive selection for loss-of-function of SERPINA2 protein. They suggest that the partial pseudogenization in humans may indicate an ongoing process of pseudogenization [19].

SERPINA3 is an inhibitory protein formerly known as antichymotrypsin. It inhibits chymotrypsin and cathepsin G [3,16]. This serpin is normally found in blood, liver, kidney, and lung.

SERPINA4 is an inhibitory protein formerly known as kallistatin (PI4), which inhibits kallikrein [20]. It is expressed in blood, liver, kidney, and heart.

SERPINA5, formerly a protein C inhibitor, inhibits active protein C. It is present in blood, kidney and liver.

SERPINA6 was formerly known as corticosteroid-binding globulin. It is a non-inhibitory protein that binds hormones, i.e., cortisol [16].

SERPINA7, formerly thyroxine-binding globulin, is involved in non-inhibitory thyroid hormone transport. It is expressed in blood, kidney, and heart.

SERPINA8 is now referred to as angiotensinogen (AGT), which is a hormone precursor. It has a distinct serpin domain (phylogenetically unrelated to other clade A members in the current analysis) and a distinct, smaller, agt domain. This particular serpin domain appears to be more closely associated with SERPINF and SERPING [21].

SERPINA9 appears to have a role in naïve B cell maintenance. Formerly called centerin, it is expressed in the plasma and liver.

SERPINA10 is an inhibitory protein responsible for inhibition of activated coagulation factors Z and XI [3]. Formerly known as protein Z-dependent proteinase inhibitor, it is expressed in blood and liver.

SERPINA11 is likely a pseudogene and is uncharacterized.

SERPINA12, formerly vaspin, inhibits kallikrein [22] and plays a role in insulin sensitivity [23]. It appears to be expressed in plasma, platelets, liver and heart.

In the mouse (Table 3), Serpina1 has been expanded to include six members, af. Serpina3 has been expanded to include nine members, ac and fn. The other clade a members are orthologous to human genes. Serpina8, now known as Agt in the mouse, is vital for the development and function of the renin-angiotensin system [24]. It is orthologous to AGT in humans.

Clade B

Clade B consists of intracellular serpins, including ov-serpins, which are ancestral to the extracellular serpins [16]. Members of this subfamily have shorter C and N termini than typical A members and also lack the secretory signal peptide sequence [4]. There are 13 human genes in clade B and one pseudogene. Serpins in clade B are important in inflammation and immune system function as well as mucous production [25]. SERPINB1, B6, B7, and B9 are involved in immune system function with roles in neutrophil and megakaryocyte development [26,27], as well as in the inhibition of the cytotoxic granule protease granzyme B [28]. SERPINB3 and its close homolog B4 are inhibitors that have roles in mucous production [29] and are expressed in epithelial tissues, such as tongue, tonsils, uterus, cervix, and vagina as well as in the upper respiratory tract and thymus [30].

Despite elusive function, SERPINB3 appears to have a role in apoptotic regulation and immunity, which implicates B3 in tumor metastasis and autoimmunity [30]. SERPINB5 has been shown to inhibit metastasis as a tumor suppressor in breast and prostate cancer [30,31]. In addition, multiple serpins in the B clade have been associated with oral squamous cell carcinoma, specifically SERPINB12, SERPINB13, SERPINB4, SERPINB3, SERPINB11, SERPINB7, and SERPINB2 [32]. Less is known about SERPINB10–B13. However, recent evidence points to a role for SERPINB13 in autoimmune diabetes progression and in inflammation [33].

SERPINB1 is an inhibitor of neutrophil elastase. It was formerly called monocyte neutrophil elastase inhibitor and is expressed ubiquitously.

SERPINB2 inhibits PLAU (uPA). It was formerly called plasminogen activator inhibitor 2 (PAI2) and is expressed in blood, kidney, and liver.

SERPINB3 is a cross-class inhibitor of cathepsin L and V [34]. Formerly referred to as squamous cell carcinoma antigen 1, it is expressed in blood, immune cells, kidney, lung, heart, and brain as well as numerous mucosal cells.

SERPINB4 was formerly known as squamous cell carcinoma antigen 2; it was discovered with SERPINB3 [25]. It is a cross-class inhibitor of cathepsin G and chymase [35] and is found in plasma, platelets, kidney, and heart, as well as saliva.

SERPINB5 is a non-inhibitory protein formerly called maspin. It is likely expressed in blood, kidney, liver, lung, as well as saliva.

SERPINB6, formerly called proteinase inhibitor 6 (PI6), is an inhibitor of granule protease, cathepsin G [36]. It is expressed ubiquitously.

SERPINB7 is involved in mesangial cell proliferation [37]. Formerly called megsin, it is expressed in blood and liver.

SERPINB8 is an inhibitory protein. Formerly called proteinase inhibitor 8 (PI8), it is expressed in blood and heart.

SERPINB9 is an inhibitory protein. Formerly called proteinase inhibitor 9 (PI9), it is expressed in blood, liver, lung, and heart.

SERPINB10 is an inhibitory protein involved in hematopoietic and myeloid development [37]. Formerly called bomapin, it expressed in blood and possibly in the brain.

SERPINB11 is a non-inhibitory serpin in human but retains trypsin inhibitory activity in mice [38]. It appears not to exhibit tissue-specific expression; however, it is expressed in HEK cells.

SERPINB12 is a trypsin inhibitor formerly known as yukopin [39]. It is expressed in blood, kidney, liver, heart, and brain.

SERPINB13, formerly known as hurpin, is expressed in blood, kidney, and saliva.

In clade b, mouse Serpinb1 has been expanded to include three members ac; Serpinb3 as well as Serpinb6 have each expanded to include four members, ad. In mice, Serpinb4 is not listed; however, it appears that SERPINB3 and SERPINB4 are equally related to Serpinb3a, Serpinb3b, Serpinb3c, and Serpinb3d, despite the initial theory that Serpinb3d is the mouse homolog of human SERPINB3 and Serpinb3c is the mouse homolog of SERPINB4. Serpinb9 has been expanded to seven members and one pseudogene. Interestingly, Serpinb11 is an active proteinase inhibitor, whereas the human ortholog is inactive.

Clade C

Serpin clade C consists of only one serpin member, SERPINC1, more commonly known as antithrombin. SERPINC1 inhibits coagulation factors IX and X [40]. It is expressed in blood, kidney, liver, lung, heart, brain, as well as saliva.

Serpinc1 gene encodes antithrombin and is orthologous to human SERPINC1.

Clade D

Clade D has one serpin member, SERPIND1, which is an extracellular protein also known as heparin cofactor II [41]. It is an inhibitor of thrombin [42] and is expressed in blood, kidney, liver, and heart.

Serpind1 encodes heparin cofactor II and is orthologous to SERPIND1.

Clade E

Clade E has three members, E1, E2, and E3, all of which are extracellular.

SERPINE1, also known as plasminogen activator inhibitor-1 (PAI1), inhibits thrombin. It is expressed in blood, liver, and heart.

SERPINE2 is a glial-derived nexin that is important in recovery of nerve structure and function [43]. It is expressed in blood, liver, kidney, and brain.

Little is known about the function of SERPINE3.

The mouse genes in clade e (Serpine1–3) are orthologous to human SERPINE1–3.

Clade F

There are two members in SERPIN clade F.

SERPINF1 (or pigment epithelium-derived factor (PEDF)) regulates angiogenesis and is an example of a non-inhibitory serpin. It is also thought to be a neurotrophic factor [16], and appears to be expressed in blood, liver, kidney, heart, and possibly lung.

SERPINF2, also known as α-2-antiplasmin, is an inhibitor of fibrinolysis. It is found in blood, kidney, liver, and heart.

Mouse Serpinf1 and f2 genes are orthologous to the human SERPINF1 and SERPINF2 genes, respectively.

Clade G

Clade G consists of one inhibitory serpin.

SERPING1 is a complement I esterase inhibitor [44] formerly called C1 inhibitor. It is expressed in blood, liver, kidney, lung, heart, and brain.

Mouse Serping1 encodes C1 inhibitor and is orthologous to SERPING1.

Clade H

Clade H consists of one member.

SERPINH1, also known as 47-kDa heat shock protein (HSP47), does not act as a proteinase inhibitor, but rather as a chaperone for collagen [45]. It is expressed in blood, liver and heart.

Mouse Serpinh1 encodes HSP47 and is orthologous to SERPINH1. Knockouts of Serpinh1 in mice are lethal [46] and missense mutations are associated with osteogenesis imperfecta [47].

Clade I

Clade I consists of two extracellular proteins. Serpins in clade I include the following.

SERPINI1 is a neuroserpin inhibitor of PLAT (tPA), PLAU (uPA), and plasmin [48]. It is expressed in liver and possibly plasma.

SERPINI2, previously known as pancipin, has an unknown protein target but may be involved in pancreatic dysfunction [49]. It is found in platelets and plasma as well as the heart.

The genes Serpini1 and Serpini2 encode mouse neuroserpin and pancipin, respectively. These are orthologous to SERPINI1 and SERPINI2 in the human.

Clades J–P

Clades jp represent viral, nematode, horseshoe crab, blood fluke, and plant serpins [16] and will not be described further in this update.

Serpins associated with disease

Serpin polymorphisms have been associated with in many disease states, including blood clotting disorders, emphysema, cirrhosis, and dementia [15,16,50] as well as tumorigenesis and metastasis.

Mutations in SERPINA1 result in a decrease in circulating α-1-antitrypsin which is associated with emphysema and hepatocellular carcinoma [51]. Serpins are implicated in regulation of the cardiovascular system. For example, SERPINA4 depletion is related to renal and cardiovascular injury [52], SERPINA8 variations are integral to the normal function of the renin-angiotensin system and have been found to regulate blood pressure [53], and a SERPINA10 polymorphism was found to increase the risk of venous thromboembolism [54,55]. SERPINA3 deficiency is associated with emphysema [56].

Many SERPINBs are implicated in immune function and dysfunction. In many of these cases, intracellular serpins cause autoimmune antibody production, inflammation, neutropenia, and cancer metastasis [25]. SERPINC1 deficiency has been correlated with autoimmune disease, especially in patients producing antinuclear antibodies, such as those with systemic lupus erythematosus [30]. Interestingly, a SERPINA6 polymorphism has been associated with chronic fatigue syndrome [57], which is thought to be an immune disorder. SERPINA7 deficiency is associated with hyperthyroidism, and high SERPINA12 levels have been associated with insulin resistance [23].

Mutations in SERPINH1, as well as in SERPINF1, are associated with osteogenesis imperfecta [47,58].

Serpins appear to influence protein aggregation. In this respect, SERPINI1 expression has been correlated with dementia [4]. In addition, SERPINA5 accumulation has been identified in plaques in multiple sclerosis [59] and SERPINA3 polymerization may accelerate onset and severity of Alzheimer’s disease [30].

Many serpins have been implicated in cancer progression including SERPINBs (on the 18q21 locus) in oral squamous cell carcinoma [25]. Breast and prostate cancer metastases are also closely associated with SERPINB5 [60,61]. In addition, SERPINE1 appears to have a role in tumor progression [62] and metastasis [63]. Further, SERPINI2 may play a possible role in breast and pancreatic cancer metastasis [49]. Adult gliomas have significant associations with SERPINI1 [64], although its role is unknown. In addition, SERPINI1 has also been proposed as one of five biomarkers in hepatocellular carcinoma [65]. Another potential biomarker includes SERPINA9, which has been found to be strongly expressed in B cell lymphomas [66].

Mouse models of human disease

There are numerous mouse models used to study the role of SERPINs in disease. Some examples include knockout of Serpinag3 used in studying T cells in immunology [67], hepatic specific knockout of Serpinc1, which exhibits coagulopathy [68], and Agt knockout to study blood pressure regulation and the renin-angiotensin system where adipocyte-specific knockout of agt caused decreased systolic blood pressure [69]. Serpinb1 knockout mice show neutropenia [70].

Gene variants in SERPINS

A large number of human variants of serpin genes have been found. For example, NCBI’s dbSNP database (http://www.ncbi.nlm.nih.gov/snp) has 621 entries for SNPs of SERPINA1 alone (accessed October 2013). In addition, several groups have developed specific databases for individual SERPIN genes. These include databases for SERPINA1[71], SERPINC3[72], and SERPING1[73]. A number of pathologies in humans have been attributed to SERPIN gene variants, and often multiple deleterious mutations are known for each gene. Although a full listing of disease-causing SERPIN mutations is beyond the scope of this review, a sample of their scope is provided here. Mutations in the SERPINA1 gene have been linked with early-onset pulmonary emphysema, neonatal hepatitis, liver cirrhosis, and sometimes panniculitis and vasculitis [74,75]. SERPINA5 mutations have been linked with increased papillary thyroid cancer risk [76], and mutations in SERPINA10 have been linked to pregnancy complications [77]. Predisposition to familial venous thromboembolic disease has been linked to mutations in SERPINC1[78,79]. Finally, SNP variants for the SERPING1 gene have been shown to be associated with hereditary angioedema [80].

Conclusions

Serpins are a large class of diverse proteins, which contribute to numerous physiological and pathological conditions. Identification of serpins in immunological functions, pathology due to polymerization, and cancer metastasis underscores their diverse functions and physiological and pathological importance, and gene mutations often lead to loss-of-function and pathology in affected individuals. However, there is still much to learn about the functions and evolutionary development of serpins. Because of numerous biological functions and pathological states associated with serpins, further characterization of these proteins and mechanistic information will provide insight into potential biomarker identification and therapeutic targets.

Competing interests

The authors declare that they have no competing interests.

Authors’ contributions

CH carried out the sequence alignments and drafted the manuscript. BJ participated in the sequence alignment and analysis. MM reviewed mouse gene/protein data and the nomenclature for accuracy and completeness. MW reviewed human gene/protein data and nomenclature for accuracy and completeness. DT, GS and DWN reviewed and edited the manuscript. VV designed the study and reviewed data and manuscript. All authors read and approved the final manuscript.

Acknowledgements

This work was supported, in part, by the following NIH grants: R24 AA022057, NIEHS P30 ES06096, HG000330, U41HG003345 and also by a Welcome Trust grant no. 099129/Z/12/Z. Fellowship assistance for BCJ (F31 AA020728) is acknowledged. We would like to thank Konstandinos Vasiliou for his assistance.

References

  • Wright HT. Introns and higher-order structure in the evolution of serpins. J Mol Evol. 1993;7:136–143. doi: 10.1007/BF00166249. [Cross Ref]
  • Potempa J, Korzus E, Travis J. The serpin superfamily of proteinase inhibitors: structure, function, and regulation. J Biol Chem. 1994;7:15957–15960. [PubMed]
  • Law RH, Zhang Q, McGowan S, Buckle AM, Silverman GA, Wong W, Rosado CJ, Langendorf CG, Pike RN, Bird PI, Whisstock JC. An overview of the serpin superfamily. Genome Biol. 2006;7:216. doi: 10.1186/gb-2006-7-5-216. [PMC free article] [PubMed] [Cross Ref]
  • Silverman GA, Bird PI, Carrell RW, Church FC, Coughlin PB, Gettins PG, Irving JA, Lomas DA, Luke CJ, Moyer RW, Pemberton PA, Remold-O’Donnell E, Salvesen GS, Travis J, Whisstock JC. The serpins are an expanding superfamily of structurally similar but functionally diverse proteins: evolution, mechanism of inhibition, novel functions, and a revised nomenclature. J Biol Chem. 2001;7:33293–33296. doi: 10.1074/jbc.R100016200. [PubMed] [Cross Ref]
  • Schechter I, Berger A. On the size of the active site in proteases: I. Papain. Biochem Biophys Res Commun. 1967;7:157–162. doi: 10.1016/S0006-291X(67)80055-X. [PubMed] [Cross Ref]
  • Huber R, Carrell RW. Implications of the three-dimensional structure of alpha 1-antitrypsin for structure and function of serpins. Biochemistry-US. 1989;7:8951–8966. doi: 10.1021/bi00449a001. [PubMed] [Cross Ref]
  • Rein CM, Desai UR, Church FC. Serpin-glycosaminoglycan interactions. Methods Enzymol. 2011;7:105–137. [PubMed]
  • Yamasaki M, Sendall TJ, Pearce MC, Whisstock JC, Huntington JA. Molecular basis of alpha1-antitrypsin deficiency revealed by the structure of a domain-swapped trimer. EMBO Rep. 2011;7:1011–1017. doi: 10.1038/embor.2011.171. [PMC free article] [PubMed] [Cross Ref]
  • Huntington JA. Serpin structure, function and dysfunction. J Thromb Haemost. 2011;7(1):26–34. [PubMed]
  • Krem MM, Di Cera E. Conserved ser residues, the shutter region, and speciation in serpin evolution. J Biol Chem. 2003;7:37810–37814. doi: 10.1074/jbc.M305088200. [PubMed] [Cross Ref]
  • Billingsley GD, Walter MA, Hammond GL, Cox DW. Physical mapping of four serpin genes: alpha 1-antitrypsin, alpha 1-antichymotrypsin, corticosteroid-binding globulin, and protein C inhibitor, within a 280-kb region on chromosome I4q32.1. Am J Hum Genet. 1993;7:343–353. [PMC free article] [PubMed]
  • Rollini P, Fournier RE. A 370-kb cosmid contig of the serpin gene cluster on human chromosome 14q32.1: molecular linkage of the genes encoding alpha 1-antichymotrypsin, protein C inhibitor, kallistatin, alpha 1-antitrypsin, and corticosteroid-binding globulin. Genomics. 1997;7:409–415. doi: 10.1006/geno.1997.5077. [PubMed] [Cross Ref]
  • Long M, de Souza SJ, Gilbert W. Evolution of the intron-exon structure of eukaryotic genes. Curr Opin Genet Dev. 1995;7:774–778. doi: 10.1016/0959-437X(95)80010-3. [PubMed] [Cross Ref]
  • Logsdon JM Jr, Stoltzfus A, Doolittle WF. Molecular evolution: recent cases of spliceosomal intron gain? Curr Biol. 1998;7:R560–R563. doi: 10.1016/S0960-9822(07)00361-2. [PubMed] [Cross Ref]
  • Clarke EP, Cates GA, Ball EH, Sanwal BD. A collagen-binding protein in the endoplasmic reticulum of myoblasts exhibits relationship with serine protease inhibitors. J Biol Chem. 1991;7:17230–17235. [PubMed]
  • Irving JA, Pike RN, Lesk AM, Whisstock JC. Phylogeny of the serpin superfamily: implications of patterns of amino acid conservation for structure and function. Genome Res. 2000;7:1845–1864. doi: 10.1101/gr.GR-1478R. [PubMed] [Cross Ref]
  • Clemmensen SN, Jacobsen LC, Rorvig S, Askaa B, Christenson K, Iversen M, Jorgensen MH, Larsen MT, van Deurs B, Ostergaard O, Heegaard NH, Cowland JB, Borregaard N. Alpha-1-antitrypsin is produced by human neutrophil granulocytes and their precursors and liberated during granule exocytosis. Eur J Haematol. 2011;7:517–530. doi: 10.1111/j.1600-0609.2011.01601.x. [PubMed] [Cross Ref]
  • Marques PI, Ferreira Z, Martins M, Figueiredo J, Silva DI, Castro P, Morales-Hojas R, Simoes-Correia J, Seixas S. SERPINA2 is a novel gene with a divergent function from SERPINA1. PLoS One. 2013;7:e66889. doi: 10.1371/journal.pone.0066889. [PMC free article] [PubMed] [Cross Ref]
  • Seixas S, Suriano G, Carvalho F, Seruca R, Rocha J, Di Rienzo A. Sequence diversity at the proximal 14q32.1 SERPIN subcluster: evidence for natural selection favoring the pseudogenization of SERPINA2. Mol Biol Evol. 2007;7:587–598. [PubMed]
  • Chao J, Schmaier A, Chen LM, Yang Z, Chao L. Kallistatin, a novel human tissue kallikrein inhibitor: levels in body fluids, blood cells, and tissues in health and disease. J Lab Clin Med. 1996;7:612–620. doi: 10.1016/S0022-2143(96)90152-3. [PubMed] [Cross Ref]
  • Paterson MA, Horvath AJ, Pike RN, Coughlin PB. Molecular characterization of centerin, a germinal centre cell serpin. Biochem J. 2007;7:489–494. doi: 10.1042/BJ20070174. [PMC free article] [PubMed] [Cross Ref]
  • Heiker JT, Kloting N, Kovacs P, Kuettner EB, Strater N, Schultz S, Kern M, Stumvoll M, Bluher M, Beck-Sickinger AG. Vaspin inhibits kallikrein 7 by serpin mechanism. Cell Mol Life Sci. 2013;7:2569–2583. doi: 10.1007/s00018-013-1258-8. [PMC free article] [PubMed] [Cross Ref]
  • Teshigawara S, Wada J, Hida K, Nakatsuka A, Eguchi J, Murakami K, Kanzaki M, Inoue K, Terami T, Katayama A, Iseda I, Matsushita Y, Miyatake N, McDonald JF, Hotta K, Makino H. Serum vaspin concentrations are closely related to insulin resistance, and rs77060950 at SERPINA12 genetically defines distinct group with higher serum levels in Japanese population. J Clin Endocrinol Metab. 2012;7:E1202–E1207. doi: 10.1210/jc.2011-3297. [PubMed] [Cross Ref]
  • Hilgers KF, Norwood VF, Gomez RA. Angiotensin’s role in renal development. Semin Nephrol. 1997;7:492–501. [PubMed]
  • Vidalino L, Doria A, Quarta S, Zen M, Gatta A, Pontisso P. SERPINB3, apoptosis and autoimmunity. Autoimmun Rev. 2009;7:108–112. doi: 10.1016/j.autrev.2009.03.011. [PubMed] [Cross Ref]
  • Tsujimoto M, Tsuruoka N, Ishida N, Kurihara T, Iwasa F, Yamashiro K, Rogi T, Kodama S, Katsuragi N, Adachi M, Katayama T, Nakao M, Yamaichi K, Hashino J, Haruyama M, Miura K, Nakanishi T, Nakazato H, Teramura M, Mizoguchi H, Yamaguchi N. Purification, cDNA cloning, and characterization of a new serpin with megakaryocyte maturation activity. J Biol Chem. 1997;7:15373–15380. doi: 10.1074/jbc.272.24.15373. [PubMed] [Cross Ref]
  • Miyata T, Inagi R, Nangaku M, Imasawa T, Sato M, Izuhara Y, Suzuki D, Yoshino A, Onogi H, Kimura M, Sugiyama S, Kurokawa K. Overexpression of the serpin megsin induces progressive mesangial cell proliferation and expansion. J Clin Invest. 2002;7:585–593. [PMC free article] [PubMed]
  • Sun J, Bird CH, Sutton V, McDonald L, Coughlin PB, De Jong TA, Trapani JA, Bird PI. A cytosolic granzyme B inhibitor related to the viral apoptotic regulator cytokine response modifier A is present in cytotoxic lymphocytes. J Biol Chem. 1996;7:27802–27809. doi: 10.1074/jbc.271.44.27802. [PubMed] [Cross Ref]
  • Sivaprasad U, Askew DJ, Ericksen MB, Gibson AM, Stier MT, Brandt EB, Bass SA, Daines MO, Chakir J, Stringer KF, Wert SE, Whitsett JA, Le Cras TD, Wills-Karp M, Silverman GA, Khurana Hershey GK. A nonredundant role for mouse serpinb3a in the induction of mucus production in asthma. J Allergy Clin Immunol. 2011;7:254–261. doi: 10.1016/j.jaci.2010.10.009. 261 e251-256. [PMC free article] [PubMed] [Cross Ref]
  • Gatto M, Iaccarino L, Ghirardello A, Bassi N, Pontisso P, Punzi L, Shoenfeld Y, Doria A. Serpins, immunity and autoimmunity: old molecules, new functions. Clin Rev Allergy Immunol. 2013;7(2):267–280. doi: 10.1007/s12016-013-8353-3. [PubMed] [Cross Ref]
  • Zou Z, Anisowicz A, Hendrix MJ, Thor A, Neveu M, Sheng S, Rafidi K, Seftor E, Sager R. Maspin, a serpin with tumor-suppressing activity in human mammary epithelial cells. Science. 1994;7:526–529. doi: 10.1126/science.8290962. [PubMed] [Cross Ref]
  • Shiiba M, Nomura H, Shinozuka K, Saito K, Kouzu Y, Kasamatsu A, Sakamoto Y, Murano A, Ono K, Ogawara K, Uzawa K, Tanzawa H. Down-regulated expression of SERPIN genes located on chromosome 18q21 in oral squamous cell carcinomas. Oncol Rep. 2010;7:241–249. [PubMed]
  • Baldzizhar R, Fedorchuk C, Jha M, Rathinam C, Henegariu O, Czyzyk J. Anti-serpin antibody-mediated regulation of proteases in autoimmune diabetes. J Biol Chem. 2013;7:1612–1619. doi: 10.1074/jbc.M112.409664. [PMC free article] [PubMed] [Cross Ref]
  • Schick C, Pemberton PA, Shi GP, Kamachi Y, Cataltepe S, Bartuski AJ, Gornstein ER, Bromme D, Chapman HA, Silverman GA. Cross-class inhibition of the cysteine proteinases cathepsins K, L, and S by the serpin squamous cell carcinoma antigen 1: a kinetic analysis. Biochemistry-US. 1998;7:5258–5266. doi: 10.1021/bi972521d. [PubMed] [Cross Ref]
  • Schick C, Kamachi Y, Bartuski AJ, Cataltepe S, Schechter NM, Pemberton PA, Silverman GA. Squamous cell carcinoma antigen 2 is a novel serpin that inhibits the chymotrypsin-like proteinases cathepsin G and mast cell chymase. J Biol Chem. 1997;7:1849–1855. doi: 10.1074/jbc.272.3.1849. [PubMed] [Cross Ref]
  • Scott FL, Hirst CE, Sun J, Bird CH, Bottomley SP, Bird PI. The intracellular serpin proteinase inhibitor 6 is expressed in monocytes and granulocytes and is a potent inhibitor of the azurophilic granule protease, cathepsin G. Blood. 1999;7:2089–2097. [PubMed]
  • Xia Y, Zhang Y, Shi W, Liu S, Chen Y, Liang X, Ye Z. Overexpression of megsin induces mesangial cell proliferation and excretion of type IV collagen in vitro. Cell Immunol. 2011;7:413–417. doi: 10.1016/j.cellimm.2011.08.009. [PubMed] [Cross Ref]
  • Askew DJ, Cataltepe S, Kumar V, Edwards C, Pace SM, Howarth RN, Pak SC, Askew YS, Bromme D, Luke CJ, Whisstock JC, Silverman GA. SERPINB11 Is a new noninhibitory intracellular serpin: common single nucleotide polymorphisms in the scaffold impair conformational change. J Biol Chem. 2007;7:24948–24960. doi: 10.1074/jbc.M703182200. [PubMed] [Cross Ref]
  • Askew YS, Pak SC, Luke CJ, Askew DJ, Cataltepe S, Mills DR, Kato H, Lehoczky J, Dewar K, Birren B, Silverman GA. SERPINB12 is a novel member of the human ov-serpin family that is widely expressed and inhibits trypsin-like serine proteinases. J Biol Chem. 2001;7:49320–49330. doi: 10.1074/jbc.M108879200. [PubMed] [Cross Ref]
  • Huntington JA. Shape-shifting serpins–advantages of a mobile mechanism. Trends Biochem Sci. 2006;7:427–435. doi: 10.1016/j.tibs.2006.06.005. [PubMed] [Cross Ref]
  • Vicente CP, He L, Pavao MS, Tollefsen DM. Antithrombotic activity of dermatan sulfate in heparin cofactor II-deficient mice. Blood. 2004;7:3965–3970. doi: 10.1182/blood-2004-02-0598. [PubMed] [Cross Ref]
  • Rau JC, Deans C, Hoffman MR, Thomas DB, Malcom GT, Zieske AW, Strong JP, Koch GG, Church FC. Heparin cofactor II in atherosclerotic lesions from the pathobiological determinants of atherosclerosis in youth (PDAY) study. Exp Mol Pathol. 2009;7:178–183. doi: 10.1016/j.yexmp.2009.09.003. [PMC free article] [PubMed] [Cross Ref]
  • Lino MM, Atanasoski S, Kvajo M, Fayard B, Moreno E, Brenner HR, Suter U, Monard D. Mice lacking protease nexin-1 show delayed structural and functional recovery after sciatic nerve crush. J Neurosci. 2007;7:3677–3685. doi: 10.1523/JNEUROSCI.0277-07.2007. [PubMed] [Cross Ref]
  • Beinrohr L, Harmat V, Dobo J, Lorincz Z, Gal P, Zavodszky P. C1 inhibitor serpin domain structure reveals the likely mechanism of heparin potentiation and conformational disease. J Biol Chem. 2007;7:21100–21109. doi: 10.1074/jbc.M700841200. [PubMed] [Cross Ref]
  • Widmer C, Gebauer JM, Brunstein E, Rosenbaum S, Zaucke F, Drogemuller C, Leeb T, Baumann U. Molecular basis for the action of the collagen-specific chaperone Hsp47/SERPINH1 and its structure-specific client recognition. Proc Natl Acad Sci U S A. 2012;7:13243–13247. doi: 10.1073/pnas.1208072109. [PMC free article] [PubMed] [Cross Ref]
  • Nagai N, Hosokawa M, Itohara S, Adachi E, Matsushita T, Hosokawa N, Nagata K. Embryonic lethality of molecular chaperone hsp47 knockout mice is associated with defects in collagen biosynthesis. J Cell Biol. 2000;7:1499–1506. doi: 10.1083/jcb.150.6.1499. [PMC free article] [PubMed] [Cross Ref]
  • Christiansen HE, Schwarze U, Pyott SM, Al Swaid A, Al Balwi M, Alrasheed S, Pepin MG, Weis MA, Eyre DR, Byers PH. Homozygosity for a missense mutation in SERPINH1, which encodes the collagen chaperone protein HSP47, results in severe recessive osteogenesis imperfecta. Am J Hum Genet. 2010;7:389–398. doi: 10.1016/j.ajhg.2010.01.034. [PMC free article] [PubMed] [Cross Ref]
  • Osterwalder T, Cinelli P, Baici A, Pennella A, Krueger SR, Schrimpf SP, Meins M, Sonderegger P. The axonally secreted serine proteinase inhibitor, neuroserpin, inhibits plasminogen activators and plasmin but not thrombin. J Biol Chem. 1998;7:2312–2321. doi: 10.1074/jbc.273.4.2312. [PubMed] [Cross Ref]
  • Ozaki K, Nagata M, Suzuki M, Fujiwara T, Miyoshi Y, Ishikawa O, Ohigashi H, Imaoka S, Takahashi E, Nakamura Y. Isolation and characterization of a novel human pancreas-specific gene, pancpin, that is down-regulated in pancreatic cancer cells. Genes Chromosomes Cancer. 1998;7:179–185. doi: 10.1002/(SICI)1098-2264(199807)22:3<179::AID-GCC3>3.0.CO;2-T. [PubMed] [Cross Ref]
  • Carrell RW, Lomas DA. Conformational disease. Lancet. 1997;7:134–138. doi: 10.1016/S0140-6736(97)02073-4. [PubMed] [Cross Ref]
  • Saunders DN, Tindall EA, Shearer RF, Roberson J, Decker A, Wilson JA, Hayes VM. A novel SERPINA1 mutation causing serum alpha(1)-antitrypsin deficiency. PLoS One. 2012;7:e51762. doi: 10.1371/journal.pone.0051762. [PMC free article] [PubMed] [Cross Ref]
  • Liu Y, Bledsoe G, Hagiwara M, Shen B, Chao L, Chao J. Depletion of endogenous kallistatin exacerbates renal and cardiovascular oxidative stress, inflammation, and organ remodeling. Am J Physiol Renal Physiol. 2012;7:F1230–F1238. doi: 10.1152/ajprenal.00257.2012. [PMC free article] [PubMed] [Cross Ref]
  • Jeunemaitre X, Gimenez-Roqueplo AP, Celerier J, Corvol P. Angiotensinogen variants and human hypertension. Curr Hypertens Rep. 1999;7:31–41. doi: 10.1007/s11906-999-0071-0. [PubMed] [Cross Ref]
  • Van de Water N, Tan T, Ashton F, O’Grady A, Day T, Browett P, Ockelford P, Harper P. Mutations within the protein Z-dependent protease inhibitor gene are associated with venous thromboembolic disease: a new form of thrombophilia. Br J Haematol. 2004;7:190–194. doi: 10.1111/j.1365-2141.2004.05189.x. [PubMed] [Cross Ref]
  • Corral J, Gonzalez-Conejero R, Soria JM, Gonzalez-Porras JR, Perez-Ceballos E, Lecumberri R, Roldan V, Souto JC, Minano A, Hernandez-Espinosa D, Alberca I, Fontcuberta J, Vicente V. A nonsense polymorphism in the protein Z-dependent protease inhibitor increases the risk for venous thrombosis. Blood. 2006;7:177–183. doi: 10.1182/blood-2005-08-3249. [PMC free article] [PubMed] [Cross Ref]
  • Gooptu B, Hazes B, Chang WS, Dafforn TR, Carrell RW, Read RJ, Lomas DA. Inactive conformation of the serpin alpha(1)-antichymotrypsin indicates two-stage insertion of the reactive loop: implications for inhibitory function and conformational disease. Proc Natl Acad Sci U S A. 2000;7:67–72. doi: 10.1073/pnas.97.1.67. [PMC free article] [PubMed] [Cross Ref]
  • Torpy DJ, Bachmann AW, Gartside M, Grice JE, Harris JM, Clifton P, Easteal S, Jackson RV, Whitworth JA. Association between chronic fatigue syndrome and the corticosteroid-binding globulin gene ALA SER224 polymorphism. Endocr Res. 2004;7:417–429. doi: 10.1081/ERC-200035599. [PubMed] [Cross Ref]
  • Homan EP, Rauch F, Grafe I, Lietman C, Doll JA, Dawson B, Bertin T, Napierala D, Morello R, Gibbs R, White L, Miki R, Cohn DH, Crawford S, Travers R, Glorieux FH, Lee B. Mutations in SERPINF1 cause osteogenesis imperfecta type VI. J Bone Miner Res. 2011;7:2798–2803. doi: 10.1002/jbmr.487. [PMC free article] [PubMed] [Cross Ref]
  • Han MH, Hwang SI, Roy DB, Lundgren DH, Price JV, Ousman SS, Fernald GH, Gerlitz B, Robinson WH, Baranzini SE, Grinnell BW, Raine CS, Sobel RA, Han DK, Steinman L. Proteomic analysis of active multiple sclerosis lesions reveals therapeutic targets. Nature. 2008;7:1076–1081. doi: 10.1038/nature06559. [PubMed] [Cross Ref]
  • Cao D, Zhang Q, Wu LS, Salaria SN, Winter JW, Hruban RH, Goggins MS, Abbruzzese JL, Maitra A, Ho L. Prognostic significance of maspin in pancreatic ductal adenocarcinoma: tissue microarray analysis of 223 surgically resected cases. Mod Pathol. 2007;7:570–578. doi: 10.1038/modpathol.3800772. [PubMed] [Cross Ref]
  • Vecchi M, Confalonieri S, Nuciforo P, Vigano MA, Capra M, Bianchi M, Nicosia D, Bianchi F, Galimberti V, Viale G, Palermo G, Riccardi A, Campanini R, Daidone MG, Pierotti MA, Pece S, Di Fiore PP. Breast cancer metastases are molecularly distinct from their primary tumors. Oncogene. 2008;7:2148–2158. doi: 10.1038/sj.onc.1210858. [PubMed] [Cross Ref]
  • Jing Y, Kovacs K, Kurisetty V, Jiang Z, Tsinoremas N, Merchan JR. Role of plasminogen activator inhibitor-1 in urokinase’s paradoxical in vivo tumor suppressing or promoting effects. Mol Cancer Res. 2012;7:1271–1281. doi: 10.1158/1541-7786.MCR-12-0145. [PMC free article] [PubMed] [Cross Ref]
  • Klein RM, Bernstein D, Higgins SP, Higgins CE, Higgins PJ. SERPINE1 expression discriminates site-specific metastasis in human melanoma. Exp Dermatol. 2012;7:551–554. doi: 10.1111/j.1600-0625.2012.01523.x. [PMC free article] [PubMed] [Cross Ref]
  • Rajaraman P, Brenner AV, Butler MA, Wang SS, Pfeiffer RM, Ruder AM, Linet MS, Yeager M, Wang Z, Orr N, Fine HA, Kwon D, Thomas G, Rothman N, Inskip PD, Chanock SJ. Common variation in genes related to innate immunity and risk of adult glioma. Cancer Epidemiol Biomarkers Prev. 2009;7:1651–1658. doi: 10.1158/1055-9965.EPI-08-1041. [PMC free article] [PubMed] [Cross Ref]
  • Jia HL, Ye QH, Qin LX, Budhu A, Forgues M, Chen Y, Liu YK, Sun HC, Wang L, Lu HZ, Shen F, Tang ZY, Wang XW. Gene expression profiling reveals potential biomarkers of human hepatocellular carcinoma. Clin Cancer Res. 2007;7:1133–1139. doi: 10.1158/1078-0432.CCR-06-1025. [PubMed] [Cross Ref]
  • Paterson MA, Hosking PS, Coughlin PB. Expression of the serpin centerin defines a germinal center phenotype in B-cell lymphomas. Am J Clin Pathol. 2008;7:117–126. doi: 10.1309/9QKE68QU7B825A3U. [PubMed] [Cross Ref]
  • Byrne SM, Aucher A, Alyahya S, Elder M, Olson ST, Davis DM, Ashton-Rickardt PG. Cathepsin B controls the persistence of memory CD8+ T lymphocytes. J Immunol. 2012;7:1133–1143. doi: 10.4049/jimmunol.1003406. [PMC free article] [PubMed] [Cross Ref]
  • Safdar H, Cheung KL, Salvatori D, Versteeg HH, Laghmani el H, Wagenaar GT, Reitsma PH, van Vlijmen BJ. Acute and severe coagulopathy in adult mice following silencing of hepatic antithrombin and protein C production. Blood. 2013;7:4413–4416. doi: 10.1182/blood-2012-11-465674. [PubMed] [Cross Ref]
  • Yiannikouris F, Karounos M, Charnigo R, English VL, Rateri DL, Daugherty A, Cassis LA. Adipocyte-specific deficiency of angiotensinogen decreases plasma angiotensinogen concentration and systolic blood pressure in mice. Am J Physiol Regul Integr Comp Physiol. 2012;7:R244–R251. doi: 10.1152/ajpregu.00323.2011. [PMC free article] [PubMed] [Cross Ref]
  • Baumann M, Pham CT, Benarafa C. SerpinB1 is critical for neutrophil survival through cell-autonomous inhibition of cathepsin G . Blood. 2013;7:3900–3907. doi: 10.1182/blood-2012-09-455022. S3901-3906. [PMC free article] [PubMed] [Cross Ref]
  • Zaimidou S, van Baal S, Smith TD, Mitropoulos K, Ljujic M, Radojkovic D, Cotton RG, Patrinos GP. A1ATVar: a relational database of human SERPINA1 gene variants leading to alpha1-antitrypsin deficiency and application of the VariVis software. Hum Mutat. 2009;7:308–313. doi: 10.1002/humu.20857. [PubMed] [Cross Ref]
  • Lane DA, Olds RJ, Thein SL. Antithrombin III: summary of first database update. Nucleic Acids Res. 1994;7:3556–3559. [PMC free article] [PubMed]
  • Kalmar L, Hegedus T, Farkas H, Nagy M, Tordai A. HAEdb: a novel interactive, locus-specific mutation database for the C1 inhibitor gene. Hum Mutat. 2005;7:1–5. doi: 10.1002/humu.20112. [PubMed] [Cross Ref]
  • Sabina J, Tobias W. Augmentation therapy with alpha1-antitrypsin: novel perspectives. Cardiovasc Hematol Disord Drug Targets. 2013;7:90–98. [PubMed]
  • Bornhorst JA, Greene DN, Ashwood ER, Grenache DG. α1-Antitrypsin phenotypes and associated serum protein concentrations in a large clinical population. Chest. 2013;7:1000–1008. doi: 10.1378/chest.12-0564. [PubMed] [Cross Ref]
  • Brenner AV, Neta G, Sturgis EM, Pfeiffer RM, Hutchinson A, Yeager M, Xu L, Zhou C, Wheeler W, Tucker MA, Chanock SJ, Sigurdson AJ. Common single nucleotide polymorphisms in genes related to immune function and risk of papillary thyroid cancer. PLoS One. 2013;7:e57243. doi: 10.1371/journal.pone.0057243. [PMC free article] [PubMed] [Cross Ref]
  • Almawi WY, Al-Shaikh FS, Melemedjian OK, Almawi AW. Protein Z, an anticoagulant protein with expanding role in reproductive biology. Reproduction. 2013;7:R73–R80. doi: 10.1530/REP-13-0072. [PubMed] [Cross Ref]
  • Maruyama K, Morishita E, Karato M, Kadono T, Sekiya A, Goto Y, Sato T, Nomoto H, Omi W, Tsuzura S, Imai H, Asakura H, Ohtake S, Nakao S. Antithrombin deficiency in three Japanese families: one novel and two reported point mutations in the antithrombin gene. Thromb Res. 2013;7:e118–e123. doi: 10.1016/j.thromres.2013.06.001. [PubMed] [Cross Ref]
  • Hepner M, Karlaftis V. Antithrombin. Methods Mol Biol. 2013;7:355–364. doi: 10.1007/978-1-62703-339-8_28. [PubMed] [Cross Ref]
  • Bork K, Davis-Lorton M. Overview of hereditary angioedema caused by C1-inhibitor deficiency: assessment and clinical management. Eur Ann Allergy Clin Immunol. 2013;7:7–16. [PubMed]

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Multiple factors related to initial trial design may predict low patient accrual for cancer clinical trials

Reporter: Stephen J. Williams, Ph.D.

UPDATED 5/15/2019

A recently published paper in JCNI highlights results determining factors which may affect cancer trial patient accrual and the development of a predictive model of accrual issues based on those factors.

To hear a JCNI podcast on the paper click here

but below is a good posting from scienmag.com which describes their findings:

Factors predicting low patient accrual in cancer clinical trials

source: http://scienmag.com/factors-predicting-low-patient-accrual-in-cancer-clinical-trials/

Nearly one in four publicly sponsored cancer clinical trials fail to enroll enough participants to draw valid conclusions about treatments or techniques. Such trials represent a waste of scarce human and economic resources and contribute little to medical knowledge. Although many studies have investigated the perceived barriers to accrual from the patient or provider perspective, very few have taken a trial-level view and asked why certain trials are able to accrue patients faster than expected while others fail to attract even a fraction of the intended number of participants. According to a study published December 29 in the JNCI: Journal of the National Cancer Institute, a number of measurable trial characteristics are predictive of low patient accrual.

Caroline S. Bennette, M.P.H., Ph.D., of the Pharmaceutical Outcomes Research and Policy Program, University of Washington, Seattle, and colleagues from the University of Washington and the Fred Hutchinson Cancer Research Center analyzed information on 787 phase II/III clinical trials sponsored by the National Clinical Trials Network (NCTN; formerly the Cooperative Group Program) launched between 2000 and 2011. After excluding trials that closed because of toxicity or interim results, Bennette et al. found that 145 (18%) of NCTN trials closed with low accrual or were accruing at less than 50% of target accrual 3 years or more after opening.

The authors identified potential risk factors from the literature and interviews with clinical trial experts and found multiple trial-level factors that were associated with poor accrual to NCTN trials, such as increased competition for patients from currently ongoing trials, planning to enroll a higher proportion of the available patient population, and not evaluating a new investigational agent or targeted therapy. Bennette et al. then developed a multivariable prediction model of low accrual using 12 trial-level risk factors, which they reported had good agreement between predicted and observed risks of low accrual in a preliminary validation using 46 trials opened between 2012 and 2013.

The researchers conclude that “Systematically considering the overall influence of these factors could aid in the design and prioritization of future clinical trials…” and that this research provides a response to the recent directive from the Institute of Medicine to “improve selection, support, and completion of publicly funded cancer clinical trials.”

In an accompanying editorial, Derek Raghavan, M.D., Levine Cancer Institute, writes that the focus needs to be on getting more patients involved in trials, saying, “we should strive to improve trial enrollment, giving the associated potential for improved results. Whether the basis is incidental, because of case selection bias, or reflects the support available to trial patients has not been determined, but the fact remains that outcomes are better.”

###

Contact info:

Article: Caroline S. Bennette, M.P.H., Ph.D., cb11@u.washington.edu

Editorial: Derek Raghavan, M.D., derek.raghavan@carolinashealthcare.org

Other investigators also feel that initial trial design is of UTMOST importance for other reasons, especially in the era of “precision” or “personalized” medicine and why the “basket trial” or one size fits all trial strategy is not always feasible.

In Why the Cancer Research Paradigm Must Transition to “N-of-1” Approach

Dr. Maurie Markman, MD gives insight into why the inital setup of a trial and the multi-center basket type of  accrual can be a problematic factor in obtaining meaningful cohorts of patients with the correct mutational spectrum.

The anticancer clinical research paradigm has rapidly evolved so that subject selection is increasingly based on the presence or absence of a particular molecular biomarker in the individual patient’s malignancy. Even where eligibility does not mandate the presence of specific biological features, tumor samples are commonly collected and an attempt is subsequently made to relate a particular outcome (eg, complete or partial objective response rate; progression-free or overall survival) to the individual cancer’s molecular characteristics.

One important result of this effort has been the recognition that there are an increasing number of patient subsets within what was previously—and incorrectly—considered a much larger homogenous patient population; for example, non–small cell lung cancer (NSCLC) versus EGFR-mutation–positive NSCLC. And, while it may still be possible to conduct phase III randomized trials involving a relatively limited percentage of patients within a large malignant entity, extensive and quite expensive effort may be required to complete this task. For example, the industry-sponsored phase III trial comparing first-line crizotinib with chemotherapy (pemetrexed plus either carboplatin or cisplatin) in ALK-rearrangement–positive NSCLC, which constitutes 3% to 5% of NSCLCs, required an international multicenter effort lasting 2.5 years to accrue the required number of research subjects.1

But what if an investigator, research team, or biotech company desired to examine the clinical utility of an antineoplastic in a patient population representing an even smaller proportion of patients with NSCLC such as in the 1% of the patient population with ROS1 abnormalities,2 or in a larger percentage of patients representing 4%-6% of patients with a less common tumor type such as ovarian cancer? How realistic is it that such a randomized trial could ever be conducted?

Further, considering the resources required to initiate and successfully conduct a multicenter international phase III registration study, it is more than likely that in the near future only the largest pharmaceutical companies will be in a position to definitively test the clinical utility of an antineoplastic in a given clinical situation.

One proposal to begin to explore the benefits of targeted antineoplastics in the setting of specific molecular abnormalities has been to develop a socalled “basket trial” where patients with different types of cancers with varying treatment histories may be permitted entry, assuming a well-defined molecular target is present within their cancer. Of interest, several pharmaceutical companies have initiated such clinical research efforts.

Yet although basket trials represent an important research advance, they may not provide the answer to the molecular complexities of cancer that many investigators believe they will. The research establishment will have to take another step toward innovation to “N-of-1” designs that truly explore the unique nature of each individual’s cancer.

Trial Illustrates Weaknesses

A recent report of the results of one multicenter basket trial focused on thoracic cancers demonstrates both the strengths but also a major fundamental weakness of the basket trial approach.3

However, the investigators were forced to conclude that despite accrual of more than 600 patients onto a study conducted at two centers over a period of approximately 2 years, “this basket trial design was not feasible for many of the arms with rare mutations.”3

They concluded that they needed a larger number of participating institutions and the ability to adapt the design for different drugs and mutations. So the question to be asked is as follows: Is the basket-type approach the only alternative to evaluate the clinical relevance of a targeted antineoplastic in the presence of a specific molecular abnormality?

Of course, the correct answer to this question is surely: No!

– See more at: http://www.onclive.com/publications/Oncology-live/2015/July-2015/Why-the-Cancer-Research-Paradigm-Must-Transition-to-N-of-1-Approach#sthash.kLGwNzi3.dpuf

The following is a video on the website ClinicalTrials.gov which is a one-stop service called EveryClinicalTrial to easily register new clinical trials and streamline the process:

 

UPDATED 5/15/2019

Another possible roadblock to patient accrual has always been the fragmentation of information concerning the availability of clinical trails and coordinating access among the various trial centers, as well as performing analytics on trial data to direct new therapeutic directions.  The NIH has attempted to circumvent this problem with the cancer trials webpage trials.gov however going through the vast number of trials, patient accrual requirements, and finding contact information is a daunting task.  However certain clinical trial marketplaces are now being developed which may ease access problems to clinical trials as well as data analytic issues, as highlighted by the Scientist.com article below:

Scientist.com Launches Trial Insights, A Transformative Clinical Trials Data Analytics Solution

The world’s largest online marketplace rolls out first original service, empowering researchers with on demand insights into clinical trials to help drive therapeutic decisions

SAN DIEGO–(BUSINESS WIRE)–Scientist.com, the online marketplace for outsourced research, announced today the launch of Trial Insights, a digital reporting solution that simplifies data produced through clinical trial, biomarker and medical diagnostic studies into an intuitive and user-friendly dashboard. The first of its kind, Trial Insights curates publicly available data nightly from information hubs such as clinicaltrials.gov and customizes it to fit a researcher or research organization’s specific project needs.

Trial Insights, new clinical trial reporting solution, allows researchers to keep track of the evolving landscape of drugs, diseases, sponsors, investigators and medical devices important to their work.

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“Trial Insights offers researchers an easy way to navigate the complexity of clinical trials information,” said Ron Ranauro, Founder of Incite Advisors. “Since Trial Insights’ content is digitally curated, researchers can continuously keep track of the evolving landscape of drugs, diseases, sponsors, investigators and medical devices important to their work.”

As the velocity, variety and veracity of data available on sites like clinicaltrials.gov continues to increase, the ability to curate it becomes more valuable to different audiences. With the advancement of personalized medicine, it is important to make the data accessible to the health care and patient communities. Information found on the Trial Insights platform can help guide decision making across the pharmaceutical, biotechnology and contract research organization industries as clinical trial data is a primary information source for competitive intelligence, research planning and clinical study planning.

“We are extremely excited to launch the first Scientist.com exclusive, original service offering to our clients in the life sciences,” said Mark Herbert, Scientist.com Chief Business Officer. “Our goal at Scientist.com is to help cure all diseases by 2050, and we believe solutions like Trial Insights, which greatly simplifies access to and reporting of clinical trial data, will get us one step closer to reaching that goal.”

source: https://www.businesswire.com/news/home/20190416005362/en/Scientist.com-Launches-Trial-Insights-Transformative-Clinical-Trials?utm_source=TrialIO+List

 

Other article on this Open Access Journal on Cancer Clinical Trial Design include:

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False-Positive Mammogram Results May Be Linked to Higher Risk Later in Life

While screening mammograms aren’t perfect, they are the best way we have right now to detect breast cancer early, when it’s most treatable.

When a screening mammogram shows an abnormal area that looks like a cancer but turns out to be normal, it’s called a false positive. Ultimately the news is good: no breast cancer. But the suspicious area usually requires follow-up with more than one doctor, extra tests, and extra procedures, including a possible biopsy.

A large study suggests that women with false-positive mammogram results have a slightly higher risk of developing invasive breast cancer within the next 10 years.

The research was published online on Dec. 2, 2015 by the journal Cancer Epidemiology, Biomarkers & Prevention. Read the abstract of “Increased Risk of Developing Breast Cancer after a False-Positive Screening Mammogram.”

To do the study, the researchers looked at information from nearly 1.3 million women ages 40 to 70 with no family history of breast cancer who had screening mammograms from 1994 to 2009. The information came from the Breast Cancer Surveillance Consortium database, which is maintained by the National Cancer Institute.

The researchers found that the 1,297,906 women had a total of 2,207,942 screening mammograms. There were:

  • 159,448 false-positive results with a recommendation for more imaging
  • 22,892 false-positive results with a recommendation for biopsy
  • 2,025,602 negative mammograms

Women ages 40 to 49 made up the largest percentage of false-positive mammogram results with a recommendation for more imaging (33.1%). Women with dense breasts also were more likely to have false-positive results.

The researchers then compared the rates of invasive breast cancer between women who had false-positive mammogram results and women who had negative mammogram results:

  • there were 3.91 invasive breast cancers per 1,000 person-years of follow-up among women with negative mammogram results
  • there were 5.51 invasive breast cancers per 1,000 person-years of follow-up among women with false-positive mammogram results with a recommendation for more imaging
  • there were 7.01 invasive breast cancers per 1,000 person-years of follow-up among women with false-positive mammogram results with a recommendation for biopsy

The researchers said the 10-year risk of invasive breast cancer was:

  • 39% higher in women with false-positive results with a recommendation for more imaging
  • 76% higher in women with false-positive results with a recommendation for biopsy

compared to women with negative results.

It’s important to know that the increases above are increases in relative risk — the risk of a woman with a false-positive result relative to the risk of a woman with a negative result.

In terms of absolute risk, the increase is small:

  • women with false-positive results have about a 2% risk of developing invasive disease in the 10 years after the false-positive result
  • women with negative results have about a 1% risk of developing invasive disease in the 10 years after the negative result

The researchers didn’t offer an explanation about why false-positive mammogram results appear to be linked to a slightly higher risk of invasive disease. Many experts think that the subtle changes suggested on the mammogram may be an early clue to cancer before actual cancer exists.

It’s also important to know that this association has been suggested in other studies. But the large number of women in the study and the length of follow-up add more evidence that the link between false-positive results and a somewhat higher risk of invasive disease actually exists.

“The power of this study to show the association is very strong, particularly when you combine it with the results of the other studies that have been done,” said Richard Wender, M.D., chief of cancer control at the American Cancer Society, in an interview. “I think we can now say with confidence that women who have had a previous false-positive mammogram are at somewhat higher risk for breast cancer.”

The researchers who did this study want to incorporate false-positive mammogram results into models that predict breast cancer risk.

“Now that we have this information, our hope is that we can add it into existing risk-prediction models to improve their ability to discriminate between women who will go on to develop breast cancer and those who won’t,” said Louise Henderson, Ph.D., of the University of North Carolina Lineberger Comprehensive Cancer Center, who was the lead author of the study. “We should accept that a false-positive mammogram is a risk factor for predicting future risk of breast cancer.

“In clinical terms, that means women who have a false-positive mammogram need to be particularly vigilant about keeping up with regular mammographic screening,” she continued. “The clinicians caring for these women should have a way to track women who have had a false-positive and make sure that every effort is made to keep up to date with mammography.”

It’s important to know that a false-positive mammogram result doesn’t mean you will be diagnosed with breast cancer.

“Having any history of breast biopsies is associated with a higher risk,” said Breastcancer.org President and Founder Marisa Weiss, M.D. “Breast tissue that is dense or has proliferative changes tends to lead to questions on the breast imaging. Sometimes it leads to biopsies. In contrast, breast tissue that is boring, without any extra activity, rarely leads to any kind of biopsy. That kind of inactive breast tissue is less likely to develop breast cancer.”

“This study doesn’t suggest that having a false-positive leads to breast cancer,” said Brian Wojciechowski, M.D., Breastcancer.org’s medical adviser. “Rather, it reflects an association between breast cancer risk and abnormal breast imaging. Women should not worry that getting mammograms will increase their risk of breast cancer in the future.”

There’s only one of you and you deserve the best care possible. Don’t let any obstacles get in the way of your regular screening mammograms, especially if you’ve had a false-positive result.

  • If you’re worried about cost, talk to your doctor, a local hospital social worker, or staff members at a mammogram center. Ask about free programs in your area.
  • If you’re having problems scheduling a mammogram, call the National Cancer Institute (800-4-CANCER) or the American College of Radiology (800-227-5463) to find certified mammogram providers near you.
  • If you find mammograms painful, ask the mammography center staff members how the experience can be as easy and as comfortable as possible for you.
  • If you’re concerned about unknown results or being called back for more testing, talk to your doctor about what happens when mammogram results are unclear, as well as what to expect if you’re called back for more testing.

For more information on mammograms and other tests to detect and diagnose breast cancer, visit the Breastcancer.org Screening and Testing section.


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Leaders in the CAR-T Field Are Proceeding With Cautious Hope

Reporter: Stephen J. Williams, Ph.D.

It wasn’t a long time ago, in fact the May 26, 2014 Cover Story in Forbes entitled “Is This How We’ll Cure Cancer” with cover photo of Novartis CEO Joseph Jimenez and subtitle “Will This man Cure Cancer?” highlighted the promise of CAR-T therapy as the ‘magic bullet’ therapy which will eventually cure all cancer. However, over the years, the pioneers of such therapy, while offering impressive clinical results, caution not to get to eager in calling CAR-T as the end-all-be-all cure but insist there are many issues that need be resolved.

The Allogenic Approach

In an interview for LabBiotech.eu Phillip Hemme had a discussion (and wonderful writeup) with André Choulika, the CEO of the French CAR-T miracle Cellectis on the current state of CAR-T therapy for cancer. Below is the interview in full as ther ae multiple important point Dr. Choulika mentioned, including how much is needed to be done in the field.

Cellectis’ CEO: “I’m just trying to be realistic, CAR-T is not THE miracle cure for Cancer”

 

 

Cellectis

CAR-T is solidifying in everybody’s mind as the next revolution in Cancer treatment. But there is still a lot to do…That’s basically what came out from my discussion with André Choulika, the CEO of the French CAR-T miracle Cellectis.

Cellectis is probably the most successful Biotech in France. It was founded in 1999 by Choulika himself (not alone though), following the discovery of meganucleases ability to change gene editing. Today, Cellectis is a well-known Biotech company counting over 100 employees end of October and having a market cap north of 1 Billion euros.

The company is now focused on the development of allogenic CAR-T (from generic donors  – i.e. not from the patient themself). With these universal CAR-T candidates (UCARTs). Cellectis has signed a massive partnership with the French pharma Servier, as well as Pfizer (which owns 8% of Cellectis), and has just announced two big milestones for the company within the last few weeks.

It is now able to produce it’s allogenic CAR-T in a GMP settings and it releases results from the “miracle” treatment of a 11-month old girl from the UK with multi-resistant leukemia.

 

Let’s start directly with the latest news…People seemed over-enthusiastic about UCART19…even the New York Times wrote about it. What do you think?

It’s a great news for Cellectis even though it’s still a very early result, in a single patient only. What’s important for us is that the first human patient received our treatment without showing any adverse effects (such as no cytokinetic storm) and our CAR-T cells were still active in the body 3 months after the injections.

Now, we have to expand the clinical trials to several patients and showing data from a cohort of patients. We are now on track to file the clinical trial application by the end of the year.

Your approach in the CAR-T is pretty unique. You are using donor’s cells to treat many different patients, whereas most CAR-T approaches are autologous (i.e. engineered the patient’s own cells).  Is the future in CAR-T the allogenic approach alone?

When we started to move into the CAR-T field we were pretty reluctant because there are not many examples of commercial success in the field yet. But CAR-T has still attracted many big players such as Novartis, Celgene, Juno or Kite. These each have a strong involvement in making autologous therapies work commercially (Celgene especially, which makes most of its revenue from groundbreaking and pricey cancer drugs).

On our side, we want to make this therapy accessible to a larger population and have good market access at the end. We have already pretty good reason to think it could work out well for us. We’ll see though…

Comment: Reuters published a report a few weeks ago estimating the cost of autologous CAR-T could be above $450K per treatment, which would make it economically not realistic for the healthcare payers.

CAR-T seems to be extremely hype right now. At BIO-Europe 2015, I had the impression everybody was talking about CAR-T. Do you think it could have the same impact as monoclonal antibodies?

What’s interesting with CAR-T is that you can target cells which expresses less receptors (10k receptors instead of 100k for monoclonal antibodies). This increases the targets for CAR-T and the possibilities linked.

But there are also downsides. Tissues with low expressions can become targets too and CAR-T cells would start attacking healthy cells.

People should not overemphasise CAR-T. We are still at the beginning of the beginning of this technology. And it will probably have to be combined with surgery or checkpoint inhibitors.

 

You seem pessimistic about CAR-T…?

I am just trying to be more realistic, even though I am super positive about the technology. It will bring something really great to Haematology field, but is not a cure for Cancer. It’s more of a long-haul race in the right direction as opposed to fast results, and we expect great things perhaps 20 years down the line as opposed to 2016.

But yes, it will probably not be the miracle product some people are talking about.

As for every early technology, there are many challenges associated with its development. What are the main ones worth discussing?

I would say you have four main challenges…

The administration of the cells will be challenging. We have to find way of injecting repeated doses of the product (to ensure the therapy is fully effective seeing as CAR-T cells have a limited lifespan). This is difficult because of immunogenicty against the therapy.

Secondly, combination will play an essential role too and checkpoint inhibitors should be involved.

The last two are linked to the targets.

As I mentioned before, CAR-T can be too sensitive and one way to control that would be to induce “logic gates” where the cells would only act if a combination of receptors would be present. The last challenge is to find other antigens.

Most of the CAR-T cells today target the same antigen: CD19+. We should find new antigens and many companies are on the track, including us.

 

CD19 CART

An anti-CD19 CAR-expressing T cell recognizing a CD19+ (Source: Kochenderfer et al., Nature Reviews Clinical Oncology 10, 267-276, doi: 10.1038/nrclinonc.2013.46)

Autologous CART therapy

Dr. Carl June of University of Pennsylvania, who has helped pioneer the field of CAR-T therapy for leukemia, has also been cautiously hopeful on the progress of the therapy. In his 2015 AACR National Meeting address, he highlighted some achievements they had with CAR-T therapy in both hematologic as well as solid tumors however it was stressed that there is much work to do with regards to optimization of the system, characterization of new tumor antigens for diverse tumor types, as well as the need to develop optimal treatment strategies to mitigate toxicities. Indeed many of the pioneers in the field have been proactive in helping to develop pharmacovigilance, safety, and regulatory strategies (highlighted in a post found here: NIH Considers Guidelines for CAR-T therapy: Report from Recombinant DNA Advisory Committee and mitigating toxicities in a post Steroids, Inflammation, and CAR-T Therapy) and much credit should be given to these researchers.

https://youtu.be/1sA_oz_1P5E

Cancer Research Institute’s Breakthroughs in Cancer Immunotherapy Webinar Series are offered free to the public and feature informative updates from leaders in cancer immunotherapy, followed by a moderated Q&A. On June 10, 2013, Carl H. June, M.D., a specialist in T cell biology and lymphocyte activation at the Perelman School of Medicine, University of Pennsylvania, discussed his groundbreaking work that has led to remarkable remissions of advanced cancer. He focused on recent and ongoing successes in developing treatments with T cells that have been genetically engineered to target cancer. Called chimeric antigen receptor T cells (CAR T cells), these modified immune cells have proven effective at eliminating cancer in some patients, and offer great hope for this emerging strategy in cancer immunotherapy. For more information on this webinar, or to register for upcoming webinars, please visit www.cancerresearch.org/webinars.

Below are reports from the 2015 American Society of Hematology Conference by Novartis on results from CTL109 CART therapy trials. One trial is on response rate in B-cell lymphomas and follicular cell lymphomas while the second report is ongoing trial results in childhood refractory ALL, both conducted at University of Pennsylvania.

Novartis presents response rate data for CART therapy CTL019 in lymphoma

(Ref: Global Post, NASDAQ, PR Newswire)

posted on FirstWorldPharma.com December 6th, 2015

By: Matthew Dennis

Novartis announced Sunday data from an ongoing Phase IIa study demonstrating that the experimental chimaeric antigen receptor T-cell (CART) therapy CTL019 led to an overall response rate (ORR) at three months of 47 percent in adults with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) and an ORR of 73 percent in adults with follicular lymphoma. The results of the trial were presented at the American Society of Hematology annual meeting.

Findings from the study, which was conducted by the University of Pennsylvania’s Perelman School of Medicine, include 15 adults with DLBCL and 11 with follicular lymphoma who were evaluable for response. Results showed that three patients with DLBCL who achieved a partial response (PR) to treatment at three months converted to complete response (CR) by six months. In addition, three patients with follicular lymphoma who achieved a PR at three months converted to CR by six months.

Novartis added that one DLBCL patient with a PR at three months experienced disease progression at six months after treatment. Further, one follicular lymphoma patient with a PR at three months who remained in PR at nine months experienced disease progression at approximately 12 months after treatment. The company indicated that median progression-free survival was 11.9 months for patients with follicular lymphoma and 3 months for those with DLBCL.

In the study, four patients developed cytokine release syndrome (CRS) of grade 3 or higher. Novartis noted that during CRS, patients typically experience varying degrees of influenza-like symptoms with high fevers, nausea, muscle pain, and in some cases, low blood pressure and breathing difficulties. Meanwhile, neurologic toxicity occurred in two patients in the trial, including one grade three episode of delirium and one possibly related grade five encephalopathy.

“These data add to the growing body of clinical evidence on CTL019 and illustrate its potential benefit in the treatment of relapsed and refractory non-Hodgkin lymphoma,” commented lead investigator Stephen Schuster. Novartis indicated that the findings keep CTL019 on track for submission to the FDA in 2017. Usman Azam, global head of Novartis’ cell and gene therapies unit, said “we remain consistent again with the data set.”

“It’s an attractive population, it’s a population that continues to have a huge unmet need, it’s a cornerstone of our investments,” Azam remarked. Analysts expect CART therapies, once approved, to cost up to $450 000 per patient. Novartis acknowledged that prices will be high, but declined to give further details. “With any disruptive innovation that comes, initially, cost of goods is very challenging,” Azam said, adding “as time goes on, and more patients are treated, we will simplify that cost base.”

Source: http://www.firstwordpharma.com/node/1338217?tsid=28&region_id=2#axzz3tfDVaT1f

 

 

Novartis AG (NVS)’s Experimental Therapy Wipes Out Blood Cancer in 93 Percent of Patients

Reported in Biospace.com (for full article see here)

Novaritis and University of Pennsylvania reported results of the CTL019 CART trials for the treatment of children with relapsed/refractory acute lymphoblastic leukemia at the 2015 Annual Hemotologic Society Meeting. 55 of 59 patients, or 93 percent, experienced complete remissions with CTL019. The study did show that at the end of one year, 55 percent of patients had a remission-free survival rate and that 18 patients continued to show complete remission following one year

 

Other posts on the Open Access Journal on CAR-T therapy include

 

CAR-T therapy in leukemia

Steroids, Inflammation, and CAR-T Therapy

NIH Considers Guidelines for CAR-T therapy: Report from Recombinant DNA Advisory Committee

 

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Biochemistry and Dysmetabolism of Aging and Serious Illness, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 1: Next Generation Sequencing (NGS)

Biochemistry and Dysmetabolism of Aging and Serious Illness

Curator: Larry H. Bernstein, MD, FCAP

 

White Matter Lipids as a Ketogenic Fuel Supply in Aging Female Brain: Implications for Alzheimer’s Disease

Lauren P. Klosinski, Jia Yao, Fei Yin, Alfred N. Fonteh, Michael G. Harrington, Trace A. Christensen, Eugenia Trushina, Roberta Diaz Brinton
http://www.ebiomedicine.com/article/S2352-3964(15)30192-4/abstract      DOI: http://dx.doi.org/10.1016/j.ebiom.2015.11.002
Highlights
  • Mitochondrial dysfunction activates mechanisms for catabolism of myelin lipids to generate ketone bodies for ATP production.
  • Mechanisms leading to ketone body driven energy production in brain coincide with stages of reproductive aging in females.
  • Sequential activation of myelin catabolism pathway during aging provides multiple therapeutic targets and windows of efficacy.

The mechanisms underlying white matter degeneration, a hallmark of multiple neurodegenerative diseases including Alzheimer’s, remain unclear. Herein we provide a mechanistic pathway, spanning multiple transitions of aging, that links mitochondrial dysfunction early in aging with later age white matter degeneration. Catabolism of myelin lipids to generate ketone bodies can be viewed as an adaptive survival response to address brain fuel and energy demand. Women are at greatest risk of late-onset-AD, thus, our analyses in female brain address mechanisms of AD pathology and therapeutic targets to prevent, delay and treat AD in the sex most affected with potential relevance to men.

 

White matter degeneration is a pathological hallmark of neurodegenerative diseases including Alzheimer’s. Age remains the greatest risk factor for Alzheimer’s and the prevalence of age-related late onset Alzheimer’s is greatest in females. We investigated mechanisms underlying white matter degeneration in an animal model consistent with the sex at greatest Alzheimer’s risk. Results of these analyses demonstrated decline in mitochondrial respiration, increased mitochondrial hydrogen peroxide production and cytosolic-phospholipase-A2 sphingomyelinase pathway activation during female brain aging. Electron microscopic and lipidomic analyses confirmed myelin degeneration. An increase in fatty acids and mitochondrial fatty acid metabolism machinery was coincident with a rise in brain ketone bodies and decline in plasma ketone bodies. This mechanistic pathway and its chronologically phased activation, links mitochondrial dysfunction early in aging with later age development of white matter degeneration. The catabolism of myelin lipids to generate ketone bodies can be viewed as a systems level adaptive response to address brain fuel and energy demand. Elucidation of the initiating factors and the mechanistic pathway leading to white matter catabolism in the aging female brain provides potential therapeutic targets to prevent and treat demyelinating diseases such as Alzheimer’s and multiple sclerosis. Targeting stages of disease and associated mechanisms will be critical.

3. Results

  1. 3.1. Pathway of Mitochondrial Deficits, H2O2 Production and cPLA2 Activation in the Aging Female Brain
  2. 3.2. cPLA2-sphingomyelinase Pathway Activation in White Matter Astrocytes During Reproductive Senescence
  3. 3.3. Investigation of White Matter Gene Expression Profile During Reproductive Senescence
  4. 3.4. Ultra Structural Analysis of Myelin Sheath During Reproductive Senescence
  5. 3.5. Analysis of the Lipid Profile of Brain During the Transition to Reproductive Senescence
  6. 3.6. Fatty Acid Metabolism and Ketone Generation Following the Transition to Reproductive Senescence

 

4. Discussion

Age remains the greatest risk factor for developing AD (Hansson et al., 2006, Alzheimer’s, 2015). Thus, investigation of transitions in the aging brain is a reasoned strategy for elucidating mechanisms and pathways of vulnerability for developing AD. Aging, while typically perceived as a linear process, is likely composed of dynamic transition states, which can protect against or exacerbate vulnerability to AD (Brinton et al., 2015). An aging transition unique to the female is the perimenopausal to menopausal conversion (Brinton et al., 2015). The bioenergetic similarities between the menopausal transition in women and the early appearance of hypometabolism in persons at risk for AD make the aging female a rational model to investigate mechanisms underlying risk of late onset AD.

Findings from this study replicate our earlier findings that age of reproductive senescence is associated with decline in mitochondrial respiration, increased H2O2 production and shift to ketogenic metabolism in brain (Yao et al., 2010, Ding et al., 2013, Yin et al., 2015). These well established early age-related changes in mitochondrial function and shift to ketone body utilization in brain, are now linked to a mechanistic pathway that connects early decline in mitochondrial respiration and H2O2 production to activation of the cPLA2-sphingomyelinase pathway to catabolize myelin lipids resulting in WM degeneration (Fig. 12). These lipids are sequestered in lipid droplets for subsequent use as a local source of ketone body generation via astrocyte mediated beta-oxidation of fatty acids. Astrocyte derived ketone bodies can then be transported to neurons where they undergo ketolysis to generate acetyl-CoA for TCA derived ATP generation required for synaptic and cell function (Fig. 12).

Thumbnail image of Fig. 12. Opens large image

http://www.ebiomedicine.com/cms/attachment/2040395791/2053874721/gr12.sml

Fig. 12

Schematic model of mitochondrial H2O2 activation of cPLA2-sphingomyelinase pathway as an adaptive response to provide myelin derived fatty acids as a substrate for ketone body generation: The cPLA2-sphingomyelinase pathway is proposed as a mechanistic pathway that links an early event, mitochondrial dysfunction and H2O2, in the prodromal/preclinical phase of Alzheimer’s with later stage development of pathology, white matter degeneration. Our findings demonstrate that an age dependent deficit in mitochondrial respiration and a concomitant rise in oxidative stress activate an adaptive cPLA2-sphingomyelinase pathway to provide myelin derived fatty acids as a substrate for ketone body generation to fuel an energetically compromised brain.

Biochemical evidence obtained from isolated whole brain mitochondria confirms that during reproductive senescence and in response to estrogen deprivation brain mitochondria decline in respiratory capacity (Yao et al., 2009, Yao et al., 2010, Brinton, 2008a, Brinton, 2008b, Swerdlow and Khan, 2009). A well-documented consequence of mitochondrial dysfunction is increased production of reactive oxygen species (ROS), specifically H2O2 (Boveris and Chance, 1973, Beal, 2005, Yin et al., 2014, Yap et al., 2009). While most research focuses on the damage generated by free radicals, in this case H2O2 functions as a signaling molecule to activate cPLA2, the initiating enzyme in the cPLA2-sphingomyelinase pathway (Farooqui and Horrocks, 2006, Han et al., 2003, Sun et al., 2004). In AD brain, increased cPLA2 immunoreactivity is detected almost exclusively in astrocytes suggesting that activation of the cPLA2-sphingomyelinase pathway is localized to astrocytes in AD, as opposed to the neuronal or oligodendroglial localization that is observed during apoptosis (Sun et al., 2004, Malaplate-Armand et al., 2006, Di Paolo and Kim, 2011, Stephenson et al., 1996,Stephenson et al., 1999). In our analysis, cPLA2 (Sanchez-Mejia and Mucke, 2010) activation followed the age-dependent rise in H2O2 production and was sustained at an elevated level.

Direct and robust activation of astrocytic cPLA2 by physiologically relevant concentrations of H2O2 was confirmed in vitro. Astrocytic involvement in the cPLA2-sphingomyelinase pathway was also indicated by an increase in cPLA2 positive astrocyte reactivity in WM tracts of reproductively incompetent mice. These data are consistent with findings from brains of persons with AD that demonstrate the same striking localization of cPLA2immunoreactivity within astrocytes, specifically in the hippocampal formation (Farooqui and Horrocks, 2004). While neurons and astrocytes contain endogenous levels of cPLA2, neuronal cPLA2 is activated by an influx of intracellular calcium, whereas astrocytic cPLA2 is directly activated by excessive generation of H2O2 (Sun et al., 2004, Xu et al., 2003, Tournier et al., 1997). Evidence of this cell type specific activation was confirmed by the activation of cPLA2 in astrocytes by H2O2 and the lack of activation in neurons. These data support that astrocytic, not neuronal, cPLA2 is the cellular mediator of the H2O2 dependent cPLA2-sphingomyelinase pathway activation and provide associative evidence supporting a role of astrocytic mitochondrial H2O2 in age-related WM catabolism.

The pattern of gene expression during the shift to reproductive senescence in the female mouse hippocampus recapitulates key observations in human AD brain tissue, specifically elevation in cPLA2, sphingomyelinase and ceramidase (Schaeffer et al., 2010, He et al., 2010, Li et al., 2014). Further, up-regulation of myelin synthesis, lipid metabolism and inflammatory genes in reproductively incompetent female mice is consistent with the gene expression pattern previously reported from aged male rodent hippocampus, aged female non-human primate hippocampus and human AD hippocampus (Blalock et al., 2003, Blalock et al., 2004, Blalock et al., 2010, Blalock et al., 2011, Kadish et al., 2009, Rowe et al., 2007). In these analyses of gene expression in aged male rodent hippocampus, aged female non-human primate hippocampus and human AD hippocampus down regulation of genes related to mitochondrial function, and up-regulation in multiple genes encoding for enzymes involved in ketone body metabolism occurred (Blalock et al., 2003, Blalock et al., 2004, Blalock et al., 2010, Blalock et al., 2011, Kadish et al., 2009, Rowe et al., 2007). The comparability across data derived from aging female mouse hippocampus reported herein and those derived from male rodent brain, female nonhuman brain and human AD brain strongly suggest that cPLA2-sphingomyelinase pathway activation, myelin sheath degeneration and fatty acid metabolism leading to ketone body generation is a metabolic adaptation that is generalizable across these naturally aging models and are evident in aged human AD brain. Collectively, these data support the translational relevance of findings reported herein.

Data obtained via immunohistochemistry, electron microscopy and MBP protein analyses demonstrated an age-related loss in myelin sheath integrity. Evidence for a loss of myelin structural integrity emerged in reproductively incompetent mice following activation of the cPLA2-sphingomyelinase pathway. The unraveling myelin phenotype observed following reproductive senescence and aging reported herein is consistent with the degenerative phenotype that emerges following exposure to the chemotherapy drug bortezomib which induces mitochondrial dysfunction and increased ROS generation (Carozzi et al., 2010, Cavaletti et al., 2007,Ling et al., 2003). In parallel to the decline in myelin integrity, lipid droplet density increased. In aged mice, accumulation of lipid droplets declined in parallel to the rise in ketone bodies consistent with the utilization of myelin-derived fatty acids to generate ketone bodies. Due to the sequential relationship between WM degeneration and lipid droplet formation, we posit that lipid droplets serve as a temporary storage site for myelin-derived fatty acids prior to undergoing β-oxidation in astrocytes to generate ketone bodies.

Microstructural alterations in myelin integrity were associated with alterations in the lipid profile of brain, indicative of WM degeneration resulting in release of myelin lipids. Sphingomyelin and galactocerebroside are two main lipids that compose the myelin sheath (Baumann and Pham-Dinh, 2001). Ceramide is common to both galactocerebroside and sphingomyelin and is composed of sphingosine coupled to a fatty acid. Ceramide levels increase in aging, in states of ketosis and in neurodegeneration (Filippov et al., 2012, Blazquez et al., 1999, Costantini et al., 2005). Specifically, ceramide levels are elevated at the earliest clinically recognizable stage of AD, indicating a degree of WM degeneration early in disease progression (Di Paolo and Kim, 2011,Han et al., 2002, Costantini et al., 2005). Sphingosine is statistically significantly elevated in the brains of AD patients compared to healthy controls; a rise that was significantly correlated with acid sphingomyelinase activity, Aβ levels and tau hyperphosphorylation (He et al., 2010). In our analyses, a rise in ceramides was first observed early in the aging process in reproductively incompetent mice. The rise in ceramides was coincident with the emergence of loss of myelin integrity consistent with the release of myelin ceramides from sphingomyelin via sphingomyelinase activation. Following the rise in ceramides, sphingosine and fatty acid levels increased. The temporal sequence of the lipid profile was consistent with gene expression indicating activation of ceramidase for catabolism of ceramide into sphingosine and fatty acid during reproductive senescence. Once released from ceramide, fatty acids can be transported into the mitochondrial matrix of astrocytes via CPT-1, where β-oxidation of fatty acids leads to the generation of acetyl-CoA (Glatz et al., 2010). It is well documented that acetyl-CoA cannot cross the inner mitochondrial membrane, thus posing a barrier to direct transport of acetyl-CoA generated by β-oxidation into neurons. In response, the newly generated acetyl-CoA undergoes ketogenesis to generate ketone bodies to fuel energy demands of neurons (Morris, 2005,Guzman and Blazquez, 2004, Stacpoole, 2012). Because astrocytes serve as the primary location of β-oxidation in brain they are critical to maintaining neuronal metabolic viability during periods of reduced glucose utilization (Panov et al., 2014, Ebert et al., 2003, Guzman and Blazquez, 2004).

Once fatty acids are released from myelin ceramides, they are transported into astrocytic mitochondria by CPT1 to undergo β-oxidation. The mitochondrial trifunctional protein HADHA catalyzes the last three steps of mitochondrial β-oxidation of long chain fatty acids, while mitochondrial ABAD (aka SCHAD—short chain fatty acid dehydrogenase) metabolizes short chain fatty acids. Concurrent with the release of myelin fatty acids in aged female mice, CPT1, HADHA and ABAD protein expression as well as ketone body generation increased significantly. These findings indicate that astrocytes play a pivotal role in the response to bioenergetic crisis in brain to activate an adaptive compensatory system that activates catabolism of myelin lipids and the metabolism of those lipids into fatty acids to generate ketone bodies necessary to fuel neuronal demand for acetyl-CoA and ATP.

Collectively, these findings provide a mechanistic pathway that links mitochondrial dysfunction and H2O2generation in brain early in the aging process to later stage white matter degeneration. Astrocytes play a pivotal role in providing a mechanistic strategy to address the bioenergetic demand of neurons in the aging female brain. While this pathway is coincident with reproductive aging in the female brain, it is likely to have mechanistic translatability to the aging male brain. Further, the mechanistic link between bioenergetic decline and WM degeneration has potential relevance to other neurological diseases involving white matter in which postmenopausal women are at greater risk, such as multiple sclerosis. The mechanistic pathway reported herein spans time and is characterized by a progression of early adaptive changes in the bioenergetic system of the brain leading to WM degeneration and ketone body production. Translationally, effective therapeutics to prevent, delay and treat WM degeneration during aging and Alzheimer’s disease will need to specifically target stages within the mechanistic pathway described herein. The fundamental initiating event is a bioenergetic switch from being a glucose dependent brain to a glucose and ketone body dependent brain. It remains to be determined whether it is possible to prevent conversion to or reversal of a ketone dependent brain. Effective therapeutic strategies to intervene in this process require biomarkers of bioenergetic phenotype of the brain and stage of mechanistic progression. The mechanistic pathway reported herein may have relevance to other age-related neurodegenerative diseases characterized by white matter degeneration such as multiple sclerosis.

Blood. 2015 Oct 15;126(16):1925-9.    http://dx.doi.org:/10.1182/blood-2014-12-617498. Epub 2015 Aug 14.
Targeting the leukemia cell metabolism by the CPT1a inhibition: functional preclinical effects in leukemias.
Cancer cells are characterized by perturbations of their metabolic processes. Recent observations demonstrated that the fatty acid oxidation (FAO) pathway may represent an alternative carbon source for anabolic processes in different tumors, therefore appearing particularly promising for therapeutic purposes. Because the carnitine palmitoyl transferase 1a (CPT1a) is a protein that catalyzes the rate-limiting step of FAO, here we investigated the in vitro antileukemic activity of the novel CPT1a inhibitor ST1326 on leukemia cell lines and primary cells obtained from patients with hematologic malignancies. By real-time metabolic analysis, we documented that ST1326 inhibited FAO in leukemia cell lines associated with a dose- and time-dependent cell growth arrest, mitochondrial damage, and apoptosis induction. Data obtained on primary hematopoietic malignant cells confirmed the FAO inhibition and cytotoxic activity of ST1326, particularly on acute myeloid leukemia cells. These data suggest that leukemia treatment may be carried out by targeting metabolic processes.
Oncogene. 2015 Oct 12.   http://dx.doi.org:/10.1038/onc.2015.394. [Epub ahead of print]
Tumour-suppression function of KLF12 through regulation of anoikis.
Suppression of detachment-induced cell death, known as anoikis, is an essential step for cancer metastasis to occur. We report here that expression of KLF12, a member of the Kruppel-like family of transcription factors, is downregulated in lung cancer cell lines that have been selected to grow in the absence of cell adhesion. Knockdown of KLF12 in parental cells results in decreased apoptosis following cell detachment from matrix. KLF12 regulates anoikis by promoting the cell cycle transition through S phase and therefore cell proliferation. Reduced expression levels of KLF12 results in increased ability of lung cancer cells to form tumours in vivo and is associated with poorer survival in lung cancer patients. We therefore identify KLF12 as a novel metastasis-suppressor gene whose loss of function is associated with anoikis resistance through control of the cell cycle.
Mol Cell. 2015 Oct 14. pii: S1097-2765(15)00764-9. doi: 10.1016/j.molcel.2015.09.025. [Epub ahead of print]
PEPCK Coordinates the Regulation of Central Carbon Metabolism to Promote Cancer Cell Growth.
Phosphoenolpyruvate carboxykinase (PEPCK) is well known for its role in gluconeogenesis. However, PEPCK is also a key regulator of TCA cycle flux. The TCA cycle integrates glucose, amino acid, and lipid metabolism depending on cellular needs. In addition, biosynthetic pathways crucial to tumor growth require the TCA cycle for the processing of glucose and glutamine derived carbons. We show here an unexpected role for PEPCK in promoting cancer cell proliferation in vitro and in vivo by increasing glucose and glutamine utilization toward anabolic metabolism. Unexpectedly, PEPCK also increased the synthesis of ribose from non-carbohydrate sources, such as glutamine, a phenomenon not previously described. Finally, we show that the effects of PEPCK on glucose metabolism and cell proliferation are in part mediated via activation of mTORC1. Taken together, these data demonstrate a role for PEPCK that links metabolic flux and anabolic pathways to cancer cell proliferation.
Mol Cancer Res. 2015 Oct;13(10):1408-20.   http://dx.doi.org:/10.1158/1541-7786.MCR-15-0048. Epub 2015 Jun 16.
Disruption of Proline Synthesis in Melanoma Inhibits Protein Production Mediated by the GCN2 Pathway.
Many processes are deregulated in melanoma cells and one of those is protein production. Although much is known about protein synthesis in cancer cells, effective ways of therapeutically targeting this process remain an understudied area of research. A process that is upregulated in melanoma compared with normal melanocytes is proline biosynthesis, which has been linked to both oncogene and tumor suppressor pathways, suggesting an important convergent point for therapeutic intervention. Therefore, an RNAi screen of a kinase library was undertaken, identifying aldehyde dehydrogenase 18 family, member A1 (ALDH18A1) as a critically important gene in regulating melanoma cell growth through proline biosynthesis. Inhibition of ALDH18A1, the gene encoding pyrroline-5-carboxylate synthase (P5CS), significantly decreased cultured melanoma cell viability and tumor growth. Knockdown of P5CS using siRNA had no effect on apoptosis, autophagy, or the cell cycle but cell-doubling time increased dramatically suggesting that there was a general slowdown in cellular metabolism. Mechanistically, targeting ALDH18A1 activated the serine/threonine protein kinase GCN2 (general control nonderepressible 2) to inhibit protein synthesis, which could be reversed with proline supplementation. Thus, targeting ALDH18A1 in melanoma can be used to disrupt proline biosynthesis to limit cell metabolism thereby increasing the cellular doubling time mediated through the GCN2 pathway.  This study demonstrates that melanoma cells are sensitive to disruption of proline synthesis and provides a proof-of-concept that the proline synthesis pathway can be therapeutically targeted in melanoma tumors for tumor inhibitory efficacy. Mol Cancer Res; 13(10); 1408-20. ©2015 AACR.
SDHB-Deficient Cancers: The Role of Mutations That Impair Iron Sulfur Cluster Delivery.
BACKGROUND:  Mutations in the Fe-S cluster-containing SDHB subunit of succinate dehydrogenase cause familial cancer syndromes. Recently the tripeptide motif L(I)YR was identified in the Fe-S recipient protein SDHB, to which the cochaperone HSC20 binds.
METHODS:   In order to characterize the metabolic basis of SDH-deficient cancers we performed stable isotope-resolved metabolomics in a novel SDHB-deficient renal cell carcinoma cell line and conducted bioinformatics and biochemical screening to analyze Fe-S cluster acquisition and assembly of SDH in the presence of other cancer-causing SDHB mutations.

RESULTS:

We found that the SDHB(R46Q) mutation in UOK269 cells disrupted binding of HSC20, causing rapid degradation of SDHB. In the absence of SDHB, respiration was undetectable in UOK269 cells, succinate was elevated to 351.4±63.2 nmol/mg cellular protein, and glutamine became the main source of TCA cycle metabolites through reductive carboxylation. Furthermore, HIF1α, but not HIF2α, increased markedly and the cells showed a strong DNA CpG island methylator phenotype (CIMP). Biochemical and bioinformatic screening revealed that 37% of disease-causing missense mutations in SDHB were located in either the L(I)YR Fe-S transfer motifs or in the 11 Fe-S cluster-ligating cysteines.

CONCLUSIONS:

These findings provide a conceptual framework for understanding how particular mutations disproportionately cause the loss of SDH activity, resulting in accumulation of succinate and metabolic remodeling in SDHB cancer syndromes.

 

SR4 Uncouples Mitochondrial Oxidative Phosphorylation, Modulates AMPK-mTOR Signaling, and Inhibits Proliferation of HepG2 Hepatocarcinoma Cells

  1. L. Figarola, J. Singhal, J. D. Tompkins, G. W. Rogers, C. Warden, D. Horne, A. D. Riggs, S. Awasthi and S. S. Singhal.

J Biol Chem. 2015 Nov 3, [epub ahead of print]

 

CD47 Receptor Globally Regulates Metabolic Pathways That Control Resistance to Ionizing Radiation

  1. W. Miller, D. R. Soto-Pantoja, A. L. Schwartz, J. M. Sipes, W. G. DeGraff, L. A. Ridnour, D. A. Wink and D. D. Roberts.

J Biol Chem. 2015 Oct 9, 290 (41): 24858-74.

 

Knockdown of PKM2 Suppresses Tumor Growth and Invasion in Lung Adenocarcinoma

  1. Sun, A. Zhu, L. Zhang, J. Zhang, Z. Zhong and F. Wang.

Int J Mol Sci. 2015 Oct 15, 16 (10): 24574-87.

 

EglN2 associates with the NRF1-PGC1alpha complex and controls mitochondrial function in breast cancer

  1. Zhang, C. Wang, X. Chen, M. Takada, C. Fan, X. Zheng, H. Wen, Y. Liu, C. Wang, R. G. Pestell, K. M. Aird, W. G. Kaelin, Jr., X. S. Liu and Q. Zhang.

EMBO J. 2015 Oct 22, [epub ahead of print]

 

Mitochondrial Genetics Regulate Breast Cancer Tumorigenicity and Metastatic Potential.

Current paradigms of carcinogenic risk suggest that genetic, hormonal, and environmental factors influence an individual’s predilection for developing metastatic breast cancer. Investigations of tumor latency and metastasis in mice have illustrated differences between inbred strains, but the possibility that mitochondrial genetic inheritance may contribute to such differences in vivo has not been directly tested. In this study, we tested this hypothesis in mitochondrial-nuclear exchange mice we generated, where cohorts shared identical nuclear backgrounds but different mtDNA genomes on the background of the PyMT transgenic mouse model of spontaneous mammary carcinoma. In this setting, we found that primary tumor latency and metastasis segregated with mtDNA, suggesting that mtDNA influences disease progression to a far greater extent than previously appreciated. Our findings prompt further investigation into metabolic differences controlled by mitochondrial process as a basis for understanding tumor development and metastasis in individual subjects. Importantly, differences in mitochondrial DNA are sufficient to fundamentally alter disease course in the PyMT mouse mammary tumor model, suggesting that functional metabolic differences direct early tumor growth and metastatic efficiency. Cancer Res; 75(20); 4429-36. ©2015 AACR.

 

Cancer Lett. 2015 Oct 29. pii: S0304-3835(15)00656-4.    http://dx.doi.org:/10.1016/j.canlet.2015.10.025. [Epub ahead of print]
Carboxyamidotriazole inhibits oxidative phosphorylation in cancer cells and exerts synergistic anti-cancer effect with glycolysis inhibition.

Targeting cancer cell metabolism is a promising strategy against cancer. Here, we confirmed that the anti-cancer drug carboxyamidotriazole (CAI) inhibited mitochondrial respiration in cancer cells for the first time and found a way to enhance its anti-cancer activity by further disturbing the energy metabolism. CAI promoted glucose uptake and lactate production when incubated with cancer cells. The oxidative phosphorylation (OXPHOS) in cancer cells was inhibited by CAI, and the decrease in the activity of the respiratory chain complex I could be one explanation. The anti-cancer effect of CAI was greatly potentiated when being combined with 2-deoxyglucose (2-DG). The cancer cells treated with the combination of CAI and 2-DG were arrested in G2/M phase. The apoptosis and necrosis rates were also increased. In a mouse xenograft model, this combination was well tolerated and retarded the tumor growth. The impairment of cancer cell survival was associated with significant cellular ATP decrease, suggesting that the combination of CAI and 2-DG could be one of the strategies to cause dual inhibition of energy pathways, which might be an effective therapeutic approach for a broad spectrum of tumors.

 

Cancer Immunol Res. 2015 Nov;3(11):1236-47.    http://dx.doi.org:/10.1158/2326-6066.CIR-15-0036. Epub 2015 May 29.
Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies.

Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSC in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSC remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSC, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSC and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSC and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T-cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSC immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSC in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies. Cancer Immunol Res; 3(11); 1236-47. ©2015 AACR.

 

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase

  1. L. Judge, K. M. Owens, S. J. Pollock, C. F. Woeller, T. H. Thatcher, J. P. Williams, R. P. Phipps, P. J. Sime and R. M. Kottmann.

Am J Physiol Lung Cell Mol Physiol. 2015 Oct 15, 309 (8): L879-87.

 

Vitamin C selectively kills KRAS and BRAF mutant colorectal cancer cells by targeting GAPDH

  1. Yun, E. Mullarky, C. Lu, K. N. Bosch, A. Kavalier, K. Rivera, J. Roper, Chio, II, E. G. Giannopoulou, C. Rago, A. Muley, J. M. Asara, J. Paik, O. Elemento, Z. Chen, D. J. Pappin, L. E. Dow, N. Papadopoulos, S. S. Gross and L. C. Cantley.

Science. 2015 Nov 5, [epub ahead of print]

 

Down-regulation of FBP1 by ZEB1-mediated repression confers to growth and invasion in lung cancer cells

  1. Zhang, J. Wang, H. Xing, Q. Li, Q. Zhao and J. Li.

Mol Cell Biochem. 2015 Nov 6, [epub ahead of print]

 

J Mol Cell Cardiol. 2015 Oct 23. pii: S0022-2828(15)30073-0.     http://dx.doi.org:/10.1016/j.yjmcc.2015.10.002. [Epub ahead of print]
GRK2 compromises cardiomyocyte mitochondrial function by diminishing fatty acid-mediated oxygen consumption and increasing superoxide levels.

The G protein-coupled receptor kinase-2 (GRK2) is upregulated in the injured heart and contributes to heart failure pathogenesis. GRK2 was recently shown to associate with mitochondria but its functional impact in myocytes due to this localization is unclear. This study was undertaken to determine the effect of elevated GRK2 on mitochondrial respiration in cardiomyocytes. Sub-fractionation of purified cardiac mitochondria revealed that basally GRK2 is found in multiple compartments. Overexpression of GRK2 in mouse cardiomyocytes resulted in an increased amount of mitochondrial-based superoxide. Inhibition of GRK2 increased oxygen consumption rates and ATP production. Moreover, fatty acid oxidation was found to be significantly impaired when GRK2 was elevated and was dependent on the catalytic activity and mitochondrial localization of this kinase. Our study shows that independent of cardiac injury, GRK2 is localized in the mitochondria and its kinase activity negatively impacts the function of this organelle by increasing superoxide levels and altering substrate utilization for energy production.

 

Br J Pharmacol. 2015 Oct 27. doi: 10.1111/bph.13377. [Epub ahead of print]
All-trans retinoic acid protects against doxorubicin-induced cardiotoxicity by activating the Erk2 signalling pathway.
BACKGROUND AND PURPOSE:

Doxorubicin (Dox) is a powerful antineoplastic agent for treating a wide range of cancers. However, doxorubicin cardiotoxicity of the heart has largely limited its clinical use. It is known that all-trans retinoic acid (ATRA) plays important roles in many cardiac biological processes, however, the protective effects of ATRA on doxorubicin cardiotoxicity remain unknown. Here, we studied the effect of ATRA on doxorubicin cardiotoxicity and underlying mechanisms.

EXPERIMENTAL APPROACHES:

Cellular viability assays, western blotting and mitochondrial respiration analyses were employed to evaluate the cellular response to ATRA in H9c2 cells and primary cardiomyocytes. Quantitative PCR (Polymerase Chain Reaction) and gene knockdown were performed to investigate the underlying molecular mechanisms of ATRA’s effects on doxorubicin cardiotoxicity.

KEY RESULTS:

ATRA significantly inhibited doxorubicin-induced apoptosis in H9c2 cells and primary cardiomyocytes. ATRA was more effective against doxorubicin cardiotoxicity than resveratrol and dexrazoxane. ATRA also suppressed reactive oxygen species (ROS) generation, and restored the expression level of mRNA and proteins in phase II detoxifying enzyme system: Nrf2 (nuclear factor-E2-related factor 2), MnSOD (manganese superoxide dismutase), HO-1 (heme oxygenase1) as well as mitochondrial function (mitochondrial membrane integrity, mitochondrial DNA copy numbers, mitochondrial respiration capacity, biogenesis and dynamics). Both Erk1/2 (extracellular signal-regulated kinase1/2) inhibitor (U0126) and Erk2 siRNA, but not Erk1 siRNA, abolished the protective effect of ATRA against doxorubicin-induced toxicity in H9c2 cells. Remarkably, ATRA did not compromise the anticancer efficacy of doxorubicin in gastric carcinoma cells.

CONCLUSION AND IMPLICATION:

ATRA protected cardiomyocytes against doxorubicin-induced toxicity by activating the Erk2 pathway without compromising the anticancer efficacy of doxorubicin. Therefore, ATRA may be a promising candidate as a cardioprotective agent against doxorubicin cardiotoxicity.

 

Proteomic and Biochemical Studies of Lysine Malonylation Suggest Its Malonic Aciduria-associated Regulatory Role in Mitochondrial Function and Fatty Acid Oxidation

  1. Colak, O. Pougovkina, L. Dai, M. Tan, H. Te Brinke, H. Huang, Z. Cheng, J. Park, X. Wan, X. Liu, W. W. Yue, R. J. Wanders, J. W. Locasale, D. B. Lombard, V. C. de Boer and Y. Zhao.

Mol Cell Proteomics. 2015 Nov 1, 14 (11): 3056-71.

 

Foxg1 localizes to mitochondria and coordinates cell differentiation and bioenergetics

  1. Pancrazi, G. Di Benedetto, L. Colombaioni, G. Della Sala, G. Testa, F. Olimpico, A. Reyes, M. Zeviani, T. Pozzan and M. Costa.

Proc Natl Acad Sci U S A. 2015 Oct 27, 112(45): 13910-5.

 

Evidence of Mitochondrial Dysfunction within the Complex Genetic Etiology of Schizophrenia

  1. E. Hjelm, B. Rollins, F. Mamdani, J. C. Lauterborn, G. Kirov, G. Lynch, C. M. Gall, A. Sequeira and M. P. Vawter.

Mol Neuropsychiatry. 2015 Nov 1, 1 (4): 201-219.

 

Metabolic Reprogramming Is Required for Myofibroblast Contractility and Differentiation

  1. Bernard, N. J. Logsdon, S. Ravi, N. Xie, B. P. Persons, S. Rangarajan, J. W. Zmijewski, K. Mitra, G. Liu, V. M. Darley-Usmar and V. J. Thannickal.

J Biol Chem. 2015 Oct 16, 290 (42): 25427-38.

 

J Biol Chem. 2015 Oct 23;290(43):25834-46.    http://dx.doi.org:/10.1074/jbc.M115.658815. Epub 2015 Sep 4.
Kinome Screen Identifies PFKFB3 and Glucose Metabolism as Important Regulators of the Insulin/Insulin-like Growth Factor (IGF)-1 Signaling Pathway.

The insulin/insulin-like growth factor (IGF)-1 signaling pathway (ISP) plays a fundamental role in long term health in a range of organisms. Protein kinases including Akt and ERK are intimately involved in the ISP. To identify other kinases that may participate in this pathway or intersect with it in a regulatory manner, we performed a whole kinome (779 kinases) siRNA screen for positive or negative regulators of the ISP, using GLUT4 translocation to the cell surface as an output for pathway activity. We identified PFKFB3, a positive regulator of glycolysis that is highly expressed in cancer cells and adipocytes, as a positive ISP regulator. Pharmacological inhibition of PFKFB3 suppressed insulin-stimulated glucose uptake, GLUT4 translocation, and Akt signaling in 3T3-L1 adipocytes. In contrast, overexpression of PFKFB3 in HEK293 cells potentiated insulin-dependent phosphorylation of Akt and Akt substrates. Furthermore, pharmacological modulation of glycolysis in 3T3-L1 adipocytes affected Akt phosphorylation. These data add to an emerging body of evidence that metabolism plays a central role in regulating numerous biological processes including the ISP. Our findings have important implications for diseases such as type 2 diabetes and cancer that are characterized by marked disruption of both metabolism and growth factor signaling.

 

FASEB J. 2015 Oct 19.    http://dx.doi.org:/pii: fj.15-276360. [Epub ahead of print]
Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle.

Skeletal muscle mitochondrial content and oxidative capacity are important determinants of muscle function and whole-body health. Mitochondrial content and function are enhanced by endurance exercise and impaired in states or diseases where muscle function is compromised, such as myopathies, muscular dystrophies, neuromuscular diseases, and age-related muscle atrophy. Hence, elucidating the mechanisms that control muscle mitochondrial content and oxidative function can provide new insights into states and diseases that affect muscle health. In past studies, we identified Perm1 (PPARGC1- and ESRR-induced regulator, muscle 1) as a gene induced by endurance exercise in skeletal muscle, and regulating mitochondrial oxidative function in cultured myotubes. The capacity of Perm1 to regulate muscle mitochondrial content and function in vivo is not yet known. In this study, we use adeno-associated viral (AAV) vectors to increase Perm1 expression in skeletal muscles of 4-wk-old mice. Compared to control vector, AAV1-Perm1 leads to significant increases in mitochondrial content and oxidative capacity (by 40-80%). Moreover, AAV1-Perm1-transduced muscles show increased capillary density and resistance to fatigue (by 33 and 31%, respectively), without prominent changes in fiber-type composition. These findings suggest that Perm1 selectively regulates mitochondrial biogenesis and oxidative function, and implicate Perm1 in muscle adaptations that also occur in response to endurance exercise.-Cho, Y., Hazen, B. C., Gandra, P. G., Ward, S. R., Schenk, S., Russell, A. P., Kralli, A. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle.

 

A conserved MADS-box phosphorylation motif regulates differentiation and mitochondrial function in skeletal, cardiac, and smooth muscle cells.
Exposure to metabolic disease during fetal development alters cellular differentiation and perturbs metabolic homeostasis, but the underlying molecular regulators of this phenomenon in muscle cells are not completely understood. To address this, we undertook a computational approach to identify cooperating partners of the myocyte enhancer factor-2 (MEF2) family of transcription factors, known regulators of muscle differentiation and metabolic function. We demonstrate that MEF2 and the serum response factor (SRF) collaboratively regulate the expression of numerous muscle-specific genes, including microRNA-133a (miR-133a). Using tandem mass spectrometry techniques, we identify a conserved phosphorylation motif within the MEF2 and SRF Mcm1 Agamous Deficiens SRF (MADS)-box that regulates miR-133a expression and mitochondrial function in response to a lipotoxic signal. Furthermore, reconstitution of MEF2 function by expression of a neutralizing mutation in this identified phosphorylation motif restores miR-133a expression and mitochondrial membrane potential during lipotoxicity. Mechanistically, we demonstrate that miR-133a regulates mitochondrial function through translational inhibition of a mitophagy and cell death modulating protein, called Nix. Finally, we show that rodents exposed to gestational diabetes during fetal development display muscle diacylglycerol accumulation, concurrent with insulin resistance, reduced miR-133a, and elevated Nix expression, as young adult rats. Given the diverse roles of miR-133a and Nix in regulating mitochondrial function, and proliferation in certain cancers, dysregulation of this genetic pathway may have broad implications involving insulin resistance, cardiovascular disease, and cancer biology.

 

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Genetically Engineered Algae, Volume 2 (Volume Two: Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS and BioInformatics, Simulations and the Genome Ontology), Part 1: Next Generation Sequencing (NGS)

Genetically Engineered Algae

Curator: Larry H. Bernstein, MD, FCAP

 

 

Genetically engineered algae kill cancer cells

By Tim Sandle     Nov 11, 2015 in Science

http://www.digitaljournal.com/science/are-algae-the-solution-to-beating-cancer/article/449045#ixzz3rZQZ7pRj

A research group in Australia has developed algae nanoparticles. The algae have been found to kill 90 percent of cancer cells in cultured human cells. Based on this success, the modified algae have been shown to destroy cancerous tumors in mice.

 Algae is a general term for a range of single-celled microscopic photosynthetic organisms such as diatoms, and larger, multi-cellular plants, like kelp. The use of algae in cancer treatment relates to drug delivery. Some success has been achieved with the use of nanoparticles (such as nanoporous silica) to deliver anti-cancer medicines. One downside with this relates to the cost of production and the fact that some nanoparticles can be toxic. To overcome this, researchers based at the University of South Australia have used algae to model an alternative drug delivery system.
Success has been achieved with microalgae-derived nanoporous biosilica. The bio-material was derived from Thalassiosira pseudonana, which is a species of marine diatom. Diatoms are are among the most common types of phytoplankton, and they are found in the oceans, in freshwater, in soils and on damp surfaces. In studies, modified diatoms have been used as types of backpacks for the targeted delivery of anticancer drugs to tumor sites.

Lead researcher Nico Voelcker, speaking with International Business Times, explained why genetic modification was key in adapting the diatoms: “By genetically engineering diatom algae – tiny, unicellular, photosynthesising algae with a skeleton made of nanoporous silica, we are able to produce an antibody-binding protein on the surface of their shells. Anti-cancer chemotherapeutic drugs are often toxic to normal tissues.”

 Although the results are interesting, experiments in cell culture and even on mice do not necessarily translate into success in humans. A series of clinical trials will be required to verify the results and to streamline any potential treatment options.

The research is published in the journal Nature Communications, in a paper headed “Targeted drug delivery using genetically engineered diatom biosilica.”

Targeted drug delivery using genetically engineered diatom biosilica

 

The ability to selectively kill cancerous cell populations while leaving healthy cells unaffected is a key goal in anticancer therapeutics. The use of nanoporous silica-based materials as drug-delivery vehicles has recently proven successful, yet production of these materials requires costly and toxic chemicals. Here we use diatom microalgae-derived nanoporous biosilica to deliver chemotherapeutic drugs to cancer cells. The diatom Thalassiosira pseudonana is genetically engineered to display an IgG-binding domain of protein G on the biosilica surface, enabling attachment of cell-targeting antibodies. Neuroblastoma and B-lymphoma cells are selectively targeted and killed by biosilica displaying specific antibodies sorbed with drug-loaded nanoparticles. Treatment with the same biosilica leads to tumour growth regression in a subcutaneous mouse xenograft model of neuroblastoma. These data indicate that genetically engineered biosilica frustules may be used as versatile ‘backpacks’ for the targeted delivery of poorly water-soluble anticancer drugs to tumour sites.

 

Figure 1: The principle of action of the genetically engineered biosilica therapeutic nanoparticles

The principle of action of the genetically engineered biosilica therapeutic nanoparticles.

http://www.nature.com/ncomms/2015/151110/ncomms9791/carousel/ncomms9791-f1.jpg

Genetically engineered diatom biosilica (green) containing liposome-encapsulated drug molecules (yellow) can be targeted to both adherent neuroblastoma cells (red) and lymphocyte cells in suspension (purple) by functionalizing the biosilica

 

Figure 2: SEM images of T. pseudonana biosilica and analysis of IgG–HRP binding to T. pseudonana biosilica

SEM images of T. pseudonana biosilica and analysis of IgG-HRP binding to T. pseudonana biosilica.

http://www.nature.com/ncomms/2015/151110/ncomms9791/carousel/ncomms9791-f2.jpg

(a) Side view and (b) top view of cylinder-shaped biosilica from a single diatom cell. (c,d) Details of the biosilica structure showing the highly porous surface. (e) Schematic structure of the S–T8–GFP–GB1 fusion protein. S, N-terminal…

 

Figure 4: Interaction of anti-CD20 antibody-labelled GB1–biosilica with B and T cells captured on an anti-CD45 antibody microarray.

Interaction of anti-CD20 antibody-labelled GB1-biosilica with B and T cells captured on an anti-CD45 antibody microarray.

http://www.nature.com/ncomms/2015/151110/ncomms9791/carousel/ncomms9791-f4.jpg

The left panels show epifluorescence microscopy images of cells captured on microarray spots after incubation with anti-CD20 antibody-labelled biosilica (n=3). The right panels show higher magnification images within the spots. Green: b…

 

Figure 6: Interaction of anti-p75NTR–GB1–biosilica frustules with adherent cells

Interaction of anti-p75NTR-GB1-biosilica frustules with adherent cells.

http://www.nature.com/ncomms/2015/151110/ncomms9791/carousel/ncomms9791-f6.jpg

(a) Confocal fluorescence microscopy image of SH-SY5Y neuroblastoma cells and (b) BSR fibroblast cells (n=3). Red: actin (phalloidin staining, green: biosilica (GFP-labelled), blue: nucleus (Hoechst 33342 staining). (c) The left panel s…

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Signaling Stiffness Changes

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Sound Waves Levitate Cells to Detect Disease-Signaling Stiffness Changes

Wed, 11/04/2015  Acoustical Society of America (ASA)

http://www.mdtmag.com/news/2015/11/sound-waves-levitate-cells-detect-disease-signaling-stiffness-changes

 

Utah Valley University physicists are literally applying rocket science to the field of medical diagnostics. With a few key changes, the researchers used a noninvasive ultrasonic technique originally developed to detect microscopic flaws in solid fuel rockets, such as space shuttle boosters, to successfully detect cell stiffness changes associated with certain cancers and other diseases.

Brian Patchett, a research assistant and instructor within the Department of Physics at Utah Valley University, will describe the group’s method, which uses sound waves to manipulate and probe cells, during the Acoustical Society of America’s Fall 2015 Meeting, held Nov. 2-6, in Jacksonville, Fla.

The method combines a low-frequency ultrasonic wave to levitate the cells and confine them to a single layer within a fluid and a high-frequency ultrasonic wave to measure the cell’s stiffness.

 

http://www.mdtmag.com/sites/mdtmag.com/files/styles/content_body_image/public/embedded_image/2015/11/levitating-cells-sound.jpg

University Basic setup of the group’s acoustic levitation device during normal use with an ultrahigh-frequency pulser taking readings of the monolayer. (Credit: Brian Patchett/Utah Valley)

 

“An acoustic wave is a pressure wave so it travels as a wave of high and low pressure. By trapping a sound wave between a transducer — such as a speaker — and a reflective surface, we can create a ‘standing wave’ in the space between,” explained Patchett. “This standing wave has stationary layers of high and low pressure, a.k.a. ‘anti-nodes,’ and areas, ‘the nodes’ where the pressure remains the same.”

This standing wave allowed the group to acoustically levitate the cells and isolate them in manner similar to their natural state — as they would be within human tissue or the bloodstream. Previous work in this realm relied on “growing the cell cultures in a Petri dish, which tends to deform the structure, as well as create all sorts of interference,” Patchett said.

The significance of the group’s work is that it focuses on an unexplored method of measuring the properties of cells and how they change during the process of cancer and disease development. “The stiffness of the cell is the primary change detected with our high-frequency ultrasound; it reveals detailed information about the internal structure of the cell and how it changes in certain diseases,” Patchett said.

The group’s method can also help distinguish between different types of cancer — such as aggressive breast cancer vs. less aggressive forms. “By isolating the cells in a monolayer of fluid via acoustic levitation, we’re providing a better method for the detection of cell stiffness,” Patchett said. “This method can be used to explore the aspect of cells that changes during Alzheimer’s disease, the metastasis of cancer, or during the onset of autoimmune responses to better understand these conditions and provide insight into possible treatment methods.”

 

http://www.mdtmag.com/sites/mdtmag.com/files/styles/content_body_image/public/featured_image/2015/11/levitating-cells-sound2.jpg

UHFSine photo of the layers created by Sine waves. (Credit: Brian Patchett/Utah Valley University)

 

One of the group’s key findings is that “by manipulating the shape of the wave that we use for levitation in specific ways, we’re able to create more precise, sharply defined layers,” Patchett said. “And, borrowing from previous cell culture work done by our group, our high-frequency ultrasound method detects changes within the stiffness of cells with high accuracy. By isolating the cells in a levitated monolayer, we hope to see these changes more clearly so that we can gain a better understanding of what’s happening within the cell and why.”

What kinds of applications might this method find? “It’s a really fantastic research method for exploring autoimmune disorders,” pointed out Timothy Doyle, lead scientist on the project and an assistant professor of physics at Utah Valley University.

As far as other applications, the group’s method may find use in clinics, hospitals, and surgical centers as a way to immediately detect and characterize cancer or other diseases.

“Our method identifies aggressive types of breast cancer, for example, while in the operating room,” Patchett noted. “Faster than current pathology methods, it will enable doctors to ensure speedier assessments and more effective treatment plans for patients — personalized to their specific needs, which, in turn, will end up being more cost effective in the long term.”

In the near future, the group plans to apply their method to a wide range of biological materials, including white blood cells undergoing activation, which is part of the immune response to an illness.

“We’re collaborating with the Huntsman Cancer Institute — part of the University of Utah healthcare system — to explore various types of breast tissues under levitation to refine our pathology detection methods,” Patchett said. “Our goal is to provide potentially life-saving, personalized medical treatments based on our ability to quickly and effectively detect cancers and diseases in patients.”

 

 

 

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Cancer Companion Diagnostics

Curator: Larry H. Bernstein, MD, FCAP

 

Companion Diagnostics for Cancer: Will NGS Play a Role?

Patricia Fitzpatrick Dimond, Ph.D.

http://www.genengnews.com/insight-and-intelligence/companion-diagnostics-for-cancer/77900554/

Companion diagnostics (CDx), in vitro diagnostic devices or imaging tools that provide information essential to the safe and effective use of a corresponding therapeutic product, have become indispensable tools for oncologists.  As a result, analysts expect the global CDx market to reach $8.73 billion by 2019, up from from $3.14 billion in 2014.

Use of CDx during a clinical trial to guide therapy can improve treatment responses and patient outcomes by identifying and predicting patient subpopulations most likely to respond to a given treatment.

These tests not only indicate the presence of a molecular target, but can also reveal the off-target effects of a therapeutic, predicting toxicities and adverse effects associated with a drug.

For pharma manufacturers, using CDx during drug development improves the success rate of drugs being tested in clinical trials. In a study estimating the risk of clinical trial failure during non-small cell lung cancer drug development in the period between 1998 and 2012 investigators analyzed trial data from 676 clinical trials with 199 unique drug compounds.

The data showed that Phase III trial failure proved the biggest obstacle to drug approval, with an overall success rate of only 28%. But in biomarker-guided trials, the success rate reached 62%. The investigators concluded from their data analysis that the use of a CDx assay during Phase III drug development substantially improves a drug’s chances of clinical success.

The Regulatory Perspective

According to Patricia Keegen, M.D., supervisory medical officer in the FDA’s Division of Oncology Products II, the agency requires a companion diagnostic test if a new drug works on a specific genetic or biological target that is present in some, but not all, patients with a certain cancer or disease. The test identifies individuals who would benefit from the treatment, and may identify patients who would not benefit but could also be harmed by use of a certain drug for treatment of their disease. The agency classifies companion diagnosis as Class III devices, a class of devices requiring the most stringent approval for medical devices by the FDA, a Premarket Approval Application (PMA).

On August 6, 2014, the FDA finalized its long-awaited “Guidance for Industry and FDA Staff: In Vitro Companion Diagnostic Devices,” originally issued in July 2011. The final guidance stipulates that FDA generally will not approve any therapeutic product that requires an IVD companion diagnostic device for its safe and effective use before the IVD companion diagnostic device is approved or cleared for that indication.

Close collaboration between drug developers and diagnostics companies has been a key driver in recent simultaneous pharmaceutical-CDx FDA approvals, and partnerships between in vitro diagnostics (IVD) companies have proliferated as a result.  Major test developers include Roche Diagnostics, Abbott Laboratories, Agilent Technologies, QIAGEN), Thermo Fisher Scientific, and Myriad Genetics.

But an NGS-based test has yet to make it to market as a CDx for cancer.  All approved tests include PCR–based tests, immunohistochemistry, and in situ hybridization technology.  And despite the very recent decision by the FDA to grant marketing authorization for Illumina’s MiSeqDx instrument platform for screening and diagnosis of cystic fibrosis, “There still seems to be a number of challenges that must be overcome before we see NGS for targeted cancer drugs,” commented Jan Trøst Jørgensen, a consultant to DAKO, commenting on presentations at the European Symposium of Biopathology in June 2013.

Illumina received premarket clearance from the FDA for its MiSeqDx system, two cystic fibrosis assays, and a library prep kit that enables laboratories to develop their own diagnostic test. The designation marked the first time a next-generation sequencing system received FDA premarket clearance. The FDA reviewed the Illumina MiSeqDx instrument platform through its de novo classification process, a regulatory pathway for some novel low-to-moderate risk medical devices that are not substantially equivalent to an already legally marketed device.

Dr. Jørgensen further noted that “We are slowly moving away from the ‘one biomarker: one drug’ scenario, which has characterized the first decades of targeted cancer drug development, toward a more integrated approach with multiple biomarkers and drugs. This ‘new paradigm’ will likely pave the way for the introduction of multiplexing strategies in the clinic using gene expression arrays and next-generation sequencing.”

The future of CDxs therefore may be heading in the same direction as cancer therapy, aimed at staying ahead of the tumor drug resistance curve, and acknowledging the reality of the shifting genomic landscape of individual tumors. In some cases, NGS will be applied to diseases for which a non-sequencing CDx has already been approved.

Illumina believes that NGS presents an ideal solution to transforming the tumor profiling paradigm from a series of single gene tests to a multi-analyte approach to delivering precision oncology. Mya Thomae, Illumina’s vice president, regulatory affairs, said in a statement that Illumina has formed partnerships with several drug companies to develop a universal next-generation sequencing-based oncology test system. The collaborations with AstraZeneca, Janssen, Sanofi, and Merck-Serono, announced in 2014 and 2015 respectively, seek to  “redefine companion diagnostics for oncology  focused on developing a system for use in targeted therapy clinical trials with a goal of developing and commercializing a multigene panel for therapeutic selection.”

On January 16, 2014 Illumina and Amgen announced that they would collaborate on the development of a next-generation sequencing-based companion diagnostic for colorectal cancer antibody Vectibix (panitumumab). Illumina will develop the companion test on its MiSeqDx instrument.

In 2012, the agency approved Qiagen’s Therascreen KRAS RGQ PCR Kit to identify best responders to Erbitux (cetuximab), another antibody drug in the same class as Vectibix. The label for Vectibix, an EGFR-inhibiting monoclonal antibody, restricts the use of the drug for those metastatic colorectal cancer patients who harbor KRAS mutations or whose KRAS status is unknown.

The U.S. FDA, Illumina said, hasn’t yet approved a companion diagnostic that gauges KRAS mutation status specifically in those considering treatment with Vectibix.  Illumina plans to gain regulatory approval in the U.S. and in Europe for an NGS-based companion test that can identify patients’ RAS mutation status. Illumina and Amgen will validate the test platform and Illumina will commercialize the test.

Treatment Options

Foundation Medicine says its approach to cancer genomic characterization will help physicians reveal the alterations driving the growth of a patient’s cancer and identify targeted treatment options that may not have been otherwise considered.

FoundationOne, the first clinical product from Foundation Medicine, interrogates the entire coding sequence of 315 cancer-related genes plus select introns from 28 genes often rearranged or altered in solid tumor cancers.  Based on current scientific and clinical literature, these genes are known to be somatically altered in solid cancers.

These genes, the company says, are sequenced at great depth to identify the relevant, actionable somatic alterations, including single base pair change, insertions, deletions, copy number alterations, and selected fusions. The resultant fully informative genomic profile complements traditional cancer treatment decision tools and often expands treatment options by matching each patient with targeted therapies and clinical trials relevant to the molecular changes in their tumors.

As Foundation Medicine’ s NGS analyses are increasingly applied, recent clinical reports describe instances in which comprehensive genomic profiling with the FoundationOne NGS-based assay result in diagnostic reclassification that can lead to targeted drug therapy with a resulting dramatic clinical response. In several reported instances, NGS found, among the spectrum of aberrations that occur in tumors, changes unlikely to have been discovered by other means, and clearly outside the range of a conventional CDx that matches one drug to a specific genetic change.

TRK Fusion Cancer

In July 2015, the University of Colorado Cancer Center and Loxo Oncology published a research brief in the online edition of Cancer Discovery describing the first patient with a tropomyosin receptor kinase (TRK) fusion cancer enrolled in a LOXO-101 Phase I trial. LOXO-101 is an orally administered inhibitor of the TRK kinase and is highly selective only for the TRK family of receptors.

While the authors say TRK fusions occur rarely, they occur in a diverse spectrum of tumor histologies. The research brief described a patient with advanced soft tissue sarcoma widely metastatic to the lungs. The patient’s physician submitted a tumor specimen to Foundation Medicine for comprehensive genomic profiling with FoundationOne Heme, where her cancer was demonstrated to harbor a TRK gene fusion.

Following multiple unsuccessful courses of treatment, the patient was enrolled in the Phase I trial of LOXO-101 in March 2015. After four months of treatment, CT scans demonstrated almost complete tumor disappearance of the largest tumors.

The FDA’s Elizabeth Mansfield, Ph.D., director, personalized medicine staff, Office of In Vitro Diagnostics and Radiological Health, said in a recent article,  “FDA Perspective on Companion Diagnostics: An Evolving Paradigm” that “even as it seems that many questions about co-development have been resolved, the rapid accumulation of new knowledge about tumor biology and the rapid evolution of diagnostic technology are challenging FDA to continually redefine its thinking on companion diagnostics.” It seems almost inevitable that a consolidation of diagnostic testing should take place, to enable a single test or a few tests to garner all the necessary information for therapeutic decision making.”

Whether this means CDx testing will begin to incorporate NGS sequencing remains to be seen.

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