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The Development of siRNA-Based Therapies for Cancer

Posted in CANCER BIOLOGY & Innovations in Cancer Therapy, Drug Delivery Platform Technology, Nanotechnology for Drug Delivery, tagged , , , , , , , , on May 9, 2013| 6 Comments »

The Development of siRNA-Based Therapies for Cancer

Author: Ziv Raviv, PhD

Article-7.3.1.The Development of siRNA Based Therapies for Cancer

Background

The use of gene regulation technology in research and medicine had evolved rapidly since the discovery of post transcriptional gene silencing using RNA interference (RNAi). RNAi was first described in C. elegance in the 90s of the previous century. RNAi post transcriptional gene regulation is carried out by small non-coding RNA double strand RNA (dsRNA) molecules such as microRNA (miRNA; miR) and small interference RNA (siRNA), and has an important role in defending cells against parasitic nucleotide sequences (e.g. viruses) as well as in gene expression regulation.

In RNAi-mediated gene regulation, short dsRNA molecules are being transcribed in the nucleus (in the case of miRs) or introduced exogenously into the cell (in the case of synthetic siRNA or viruses), and are processed in the cytoplasm by an enzyme called Dicer that cleaves long dsRNA and pre-microRNA to produce short double-stranded RNA fragments of 21 base pairs long. The 21 nucleotides long double strand RNA is then being incorporated into the RNA-induced silencing complex (RISC) where it is unwound into two single strands RNA (ssRNA). The “guide” strand is then paired with its complementary targeted messenger RNA (mRNA) that is subsequently cleaved by Argonaute RISC-associated endonuclease. Consequently, the targeted gene protein expression is blocked, leading to its substantial reduced levels in the cell. This so called gene silencing or gene knockdown, hitting the message not the gene itself, will last as long as RNAi molecules are present. The mechanism of action of RNAi is illustrated in the following Video.

RNAi technology was then massively adapted for research allowing the evaluation of functional involvement of genes in various cellular processes because introducing synthetic siRNA into cells can selectively suppress any specific gene of interest.  Not only that RNAi serves as a valuable research tool both in cell culture and in vivo, RNAi has an extremely high potential for specific gene-targeting therapy, as many diseases consist gene deregulation. Synthetic siRNAs are perfectly and completely base pairing to a target (in contrast to endogenous miRs), leading to mRNA-induced cleavage in a single-specific manner that allows treatment without non-specific off-target side effects.

RNAi as therapeutic tool for cancer

All malignant conditions consist of gene deregulations in the form of mutations causing protein misfunction that lead to loss of cell growth regulation and consequently to cancer. Therefore, the fact that siRNA can selectively and specifically target any gene of interest creates a powerful tool to downregulate cancer-associated genes, that eventually will lead to a decrease and even abolishment of the malignant condition.

The advantages of using siRNA for therapy thus are:

  • RNAi technology represents a 3rd revolutionary step for pharmaceutics after small molecules and monoclonal antibodies (mAb), and has a strong commercial potential similar to mAb and even beyond.
  • The ability to target any gene of interest, by blocking specifically the message from DNA to protein consequently the protein is not allowed to be expressed and thus is not functioning.
  • Specificity – siRNA have strong potential to bind specifically to target mRNA, thus lowering unwanted side effects.
  • siRNAs are double stranded oligonucleotides, which are resistant to nucleases.
  • Fast pre-clinical development

General considerations for developing anti-cancer RNAi-based treatment

Given the great potential of siRNA as a therapeutic tool for cancer, one should bring into consideration some general aspects for the development of a siRNA anti-cancer drug:

  • Choosing the gene of interest to be silenced – A wide spectrum of genes could be considered as targets based upon gene of interest role in the cancer cell, type of cancer, and condition of the disease: (i) Oncogenes or central signaling molecules that are crucial for cancer cell growth (ii) Anti-apoptotic deregulated genes (iii) Cancer metabolism associated genes (iv) Angiogenic related genes (v) Metastatic condition related genes.
  • Considering the option of hitting combined target genes consist of different functions (e.g. an oncogene and an anti-apoptotic gene).
  • Basic research evaluation – To examine the effect of silencing the gene of interest in cancer cell based assays and in animal models.
  • Chemical modifications of the siRNA molecule – Modifications such as 2′OMe to increase protection from nuclease, decrease the immunogenicity, lower the incidence of off-target effects, and improve pharmacodynamics of the siRNA.
  • Drug delivery formulation – For an efficient transport of the siRNA. Such delivery system could be formulated using liposome-based nanoparticles (NP) or other nanocarriers to facilitate the siRNA effective systemic distribution.
  • PEGylation – PEGylation of the NPs carriers to reduce non-specific tissue interactions, increase serum stability and half life, and reduce immunogenicity of the siRNA molecule.
  • Site specific targeting – Target tissue-specific distribution of the siRNA drug could be performed by attaching on the outer surface of the nanocarrier a ligand that will direct the siRNA drug to the tumor site.
  • Preclinical – Efficiency and validity, as well as toxicity and pharmacokinetic studies for the siRNA-transporter formulation should be evaluated in animal models.
  • Personalized treatment – In first stages clinical trials, biomarkers should be developed and detected to direct the selection criteria for further treatment of patients with the selected siRNA.
  • Combined therapy – Conduct clinical trials using a combination of the siRNA drug together with a chemotherapy drug that is in-clinical use. Such combined therapy can result in synergism actions of the two combined drugs, and could lower the dosage and thus the side effects of the drugs. In addition, the use of established contemporary agents has practical industrial-related advantages as it is much easier to introduce a new mode of treatment on the background of an existing one.

Development of transport methods for siRNA

As mentioned above, an important aspect in applying siRNA-based therapy is the development of a suitable delivery method that should carry the siRNA molecule systemically to the site of the tumor. In addition, the siRNA-transporter formulation should provide protection from serum nucleases to the siRNA and should decrease its immunogenicity by blocking response of the innate immune system. Examples of such NPs are illustrated in Figure 1. Indeed, several clinical trials were conducted to evaluate the efficacy, validity, and safety use of such transporters for clinical use (Table I).

Figure 1: Various types of nanoparticles for siRNA delivery

Taken from: Cho K et al. Clin Cancer Res 2008;14:1310-1316

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Table I: Clinical trials examining siRNA delivery methods

T1Click on table to enlarge

Table resources: nmOK drug database and clinicaltrials.gov

Download table with active links: Development of siRNA-Based Therapies for Cancer_Table I

Current development status of RNAi-based cancer therapies  

The potential use of RNAi technology to treat cancer is versatile as for any gene of interest it is easy to synthesize a siRNA molecule and the pre-clinical development of siRNA agent is fast. Several companies specialized in siRNA technology have begun recently developing RNAi-based therapies to various cancer associated genes (as well as to other diseases) and to conduct clinical trials. Table II summaries the current clinical trials status of such siRNA-based anti-cancer agents.

Table II: Current clinical trials of siRNA therapies for cancer

T2Click on table to enlarge

Table resources: nmOK drug database, clinicaltrials.gov, and World Health Organization (WHO)

Download table with active links: Development of siRNA-Based Therapies for Cancer_Table II

Conclusion remarks

The power of siRNA-based therapeutics resides in the ability to target and silence any desired gene. Pharmaceutical and biotech companies have started to conduct clinical trials of siRNA therapies for cancer. Most of these clinical trials are in the early preclinical and phase I stages. The results expected from these experiments should further direct the development of siRNA-based anti-cancer therapies and phase II and III trials should consequently emerge. Other target genes should be evaluated as well for siRNA-anti cancer therapy in addition to those that are currently in evaluation, and accelerated efforts should be made in the direction of combining existing chemotherapy with the technology of siRNA. The next future to come will tell us if the potential of siRNA therapy for cancer had been fulfilled.

Related references:

  1. RNAi-Based Therapies for Cancer in Development. Anna Azvolinsky, PhD. Cancernetwork, March 3, 2011.
  2. siRNA-based approaches in cancer therapy. GR Devi. Cancer Gene Therapy (2006) 13, 819–829
  3. Therapeutic Effect of RNAi Gene Silencing Effective in Cancer Treatment, Study Suggests. Sciencedaily, Feb. 11, 2013.
  4. Kinesin Spindle Protein SiRNA Slows Tumor Progression. Marra E, Palombo F, Ciliberto G, Aurisicchio L. J Cell Physiol. 2013 Jan;228(1):58-64.
  5. First-in-Humans Trial of an RNA Interference Therapeutic Targeting VEGF and KSP in Cancer Patients with Liver Involvement. Josep Tabernero et al. Cancer Discov. 2013 Apr;3(4):406-417.

Chemical modification:

  1. Chemical Modification of siRNAs for In Vivo Use. Behlke MA. Oligonucleotides. 2008 Dec; 18(4):305-19.

Delivery Technology:

  1. Cancer siRNA therapy by tumor selective delivery with ligand-targeted sterically stabilized nanoparticle. Schiffelers RM et al. Nucleic Acids Res. 2004 Nov 1;32(19):e149.
  2. Therapeutic Nanoparticles for Drug Delivery in Cancer.  Kwangjae Cho, Xu Wang, Shuming Nie, et al. Clin Cancer Res 2008;14:1310-1316.
  3. Liposomes and nanoparticles: nanosized vehicles for drug delivery in cancer. Malam Y, Loizidou M, Seifalian AM. Trends Pharmacol Sci. 2009 Nov; 30(11):592-9.
  4. Silence-therapeutics delivery platform

Related articles on this Open Access Online Scientific Journal:

  1. MIT Team: Microfluidic-based approach – A Vectorless delivery of Functional siRNAs into Cells. Reporter: Aviva Lev-Ari, Ph.D., RN
  2. Targeted Tumor-Penetrating siRNA Nanocomplexes for Credentialing the Ovarian Cancer Oncogene ID4. Reporter and Curator: Sudipta Saha, Ph.D.
  3. Targeted delivery of therapeutics to bone and connective tissues: current status and challenges- Part II. Curator and Reporter: Aviral Vatsa Ph.D., MBBS
  4. Nanotechnology and HIV/AIDS treatment. Author: Tilda Barliya, PhD

To download tables of this post (with active links) :

  1. Development of siRNA-Based Therapies for Cancer_Table I
  2. Development of siRNA-Based Therapies for Cancer_Table II

Databases:

http://www.nmok.net

http://www.clinicaltrials.gov/

http://apps.who.int/trialsearch/

Related Videos:

RNA interference mechanism of action

RNA interference (RNAi): by Nature video

RNAi Therapeutics and Cancer Treatment

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Whole exome somatic mutations analysis of malignant melanoma contributes to the development of personalized cancer therapy for this disease

Posted in Biomarkers & Medical Diagnostics, CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, tagged , , , , , , , , , , on April 23, 2013| 3 Comments »

Whole exome somatic mutations analysis of malignant melanoma contributes to the development of personalized cancer therapy for this disease

Author: Ziv Raviv, PhD

Article-7.2.2. Whole exome somatic mutations analysis of malignant melanoma contributes to the development of personalized cancer therapy for this disease

Introduction

Cutaneous melanoma is a type of skin cancer that originates in melanocytes, the cells that are producing melanin. While being the least common type of skin cancer, melanoma is the most aggressive one with invasive characteristics and accounts for the majority of death incidences among skin cancers. Melanoma has an annual rate of 160,000 new cases and 48,000 deaths worldwide. Melanoma affects mainly Caucasians exposed to sun high UV irradiation. Among the genetic factors that characterize the disease, BRAF mutation (V600E) is found in most cases of melanoma (80%).  Awareness toward risk factors of melanoma should lead to prevention and early detection*. There are several developmental stages (I-IV) of the disease, starting from local non-invasive melanoma, through invasive and high risk melanoma, up to metastatic melanoma. As with other cancers, the earlier stage melanoma is being detected, the better odds for full recovery are. Treatment is usually involving surgery to remove the local tumor and its margins, and when necessary also to remove the proximal lymph node(s) that drain the tumor. In high stages melanoma, adjuvant therapy is given in the form of chemotherapy (Dacarbazine and Temozolomide) and immunotherapy (IL-2 and IFN). Until recently no useful treatment was available for metastatic melanoma. However, research efforts had led to the development of two new drugs against metastatic melanoma: Vemurafenib (Zelboraf), a B-Raf inhibitor; and Ipilimumab (Yervoy), a monoclonal antibody that blocks the inhibitory signal of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4). Both drugs are now available for clinical use presenting good results.

Personalized therapy for melanoma

In an attempt to develop personalized therapies for malignant melanoma, a unique strategy has been taken by the group of Prof. Yardena Samuels at the NIH (now situated at the WIS) to identify recurring genetic alterations of metastatic cutaneous melanoma. The researchers approach employed the collections of hundreds of tumors samples taken from metastasized melanoma patients together with matched normal blood tissues samples. The samples are undergoing exome sequencing for the analysis of somatic mutations (namely mutations that evolved during the progress of the disease to the stage of metastatic melanoma, unlike genomic mutations that may have contribute to the formation of the disease). The discrimination of such tumor related somatic mutations is done by comparison to the exome sequencing of the patient’s matched blood cells DNA. In addition, the malignant cells derived from the removed cancer tissue of each patient are extracted to form a cell line and are grown in culture. These cells are easily cultivate in culture with no special media supplements, nor further genetic manipulations such as hTERT are needed, and are extremely aggressive as determined by various cell culture and in vivo tests. The ability to grow these primary tumor-derived cell lines in culture has a great value as a tool for studying and characterizing the biochemical, functional, and clinical aspects of the mutated genes identified.

In one study [1] Samuels and her colleagues performed this sequencing process for mutation analysis for the protein tyrosine kinase (PTK) gene family, as PTKs are frequently mutated in cancer. Using high-throughput gene sequencing to analyze the entire PTK gene family, the researchers have identified 30 somatic mutations affecting the kinase domains of 19 PTKs and subsequently evaluated the entire coding regions of the genes encoding these 19 PTKs for somatic mutations in 79 melanoma samples. The most frequent mutations were found in ERBB4, a member of the EGFR/ErbB family of receptor tyrosine kinase (RTK), were 19% of melanoma patients had such mutations. Seven missense mutations in the ERBB4 gene were found to induce increased kinase activity and transformation capability. Melanoma derived cell lines that were expressing these mutant ERBB4 forms had reduced cell growth after silencing ERBB4 by RNAi or after treatment with the ERBB inhibitor Lapatinib. Lapatinib is already in use in the clinic for the treatment of HER2 (ErbB2) positive breast cancers patients. Following this study, a clinical trial is now conducted with this drug to evaluate its effect in cutaneous metastatic melanoma patients harboring mutations in ERBB4.

In another study of this group [2], the scientists employed the exome sequencing method to analyze the somatic mutations of 734 G protein coupled receptors (GPCRs) in melanoma. GPCRs are regulating various signaling pathways including those that affect cell growth and play also important role in human diseases. This screen revealed that GRM3 gene that encode the metabotropic glutamate receptor 3 (mGluR3), was frequently mutated and that one of its mutations clustered within one position. Mutant GRM3 was found to selectively regulate the phosphorylation of MEK1 leading to increased anchorage-independent cell growth and cellular migration. Tumor derived melanoma cells expressing mutant GRM3 exhibited reduced cell growth and migration upon knockdown of GRM3 by RNAi or by treatment with the selective MEK inhibitor, Selumetinib (AZD-6244), a drug that is being testing in clinical trials. Altogether, the results of this study point to the increased violent characteristics of melanomas bearing mutational GRM3.

In a third study, melanoma samples were examined for somatic mutations in 19 human genes that encode ADAMTS proteins [3]. Some of the ADAMTS genes have been suggested before to have implication in tumorigenesis. ADAMTS18, which was previously found to be a candidate cancer gene, was found in this study to be highly mutated in melanoma. ADAMTS18 mutations were biologically examined and were found to induce an increased proliferation of melanoma cells, as well as increased cell migration and metastasis. Moreover, melanoma cells expressing these mutated ADAMTS18 had reduced cell migration after RNAi-mediated knockdown of ADAMTS18. Thus, these results suggest that genetic alteration of ADAMTS18 plays a major role in melanoma tumorigenesis. Since ADAMTS genes encode extracellular proteins, their accessibility to systematically delivered drugs makes them excellent therapeutic targets.

Conclusive remarks

The above illustrated research approach intends to discover frequent melanoma-specific mutations by employing high-throughput whole exome and genome sequencing means. For the most highly mutated genes identified, the biochemical, functional, and clinical aspects are being characterized to examine their relevancy to the disease outcomes. This approach therefore introduces new opportunities for clinical intervention for the treatment of cutaneous melanoma. In addition to the discovery of novel highly mutated genes, this approach may also help determine which pathways are altered in melanoma and how these genes and pathways interact. Finding melanoma-associated highly mutated genes could lead to personalized therapeutics specifically targeting these altered genes in individual melanomas. Along with the opportunity to develop new agents to treat melanoma, the approach takes advantage of existing anti-cancer drugs, utilizing them to treat these mutated genes melanoma individuals. In addition to their potential for therapeutics, the discovery of highly mutated genes in melanoma patients may lead to the discovery of new markers that may assist the diagnosis of the disease. The implications of these screenings findings on other types of cancer bearing common pathways similar to melanoma should be examined as well. Finally, this elegant approach should be adopted in research efforts of other cancer types.

* Special review will be published further in the cancer prevention section of Pharmaceutical Intelligence

References

1. Prickett TD, Agrawal NS, Wei X, Yates KE, Lin JC, Wunderlich JR, Cronin JC, Cruz P, Rosenberg SA, Samuels Y (2009) Analysis of the tyrosine kinome in melanoma reveals recurrent mutations in ERBB4. Nat Genet 41 (10):1127-1132

2. Prickett TD, Wei X, Cardenas-Navia I, Teer JK, Lin JC, Walia V, Gartner J, Jiang J, Cherukuri PF, Molinolo A, Davies MA, Gershenwald JE, Stemke-Hale K, Rosenberg SA, Margulies EH, Samuels Y (2011) Exon capture analysis of G protein-coupled receptors identifies activating mutations in GRM3 in melanoma. Nat Genet 43 (11):1119-1126

3. Wei X, Prickett TD, Viloria CG, Molinolo A, Lin JC, Cardenas-Navia I, Cruz P, Rosenberg SA, Davies MA, Gershenwald JE, Lopez-Otin C, Samuels Y (2010) Mutational and functional analysis reveals ADAMTS18 metalloproteinase as a novel driver in melanoma. Mol Cancer Res 8 (11):1513-1525

Related articles on melanoma on this open access online scientific journal:

1.  In focus: Melanoma Genetics. Curator: Ritu Saxena, Ph.D.

2.  In focus: Melanoma therapeutics. Author and Curator: Ritu Saxena, Ph.D.

3.  A New Therapy for Melanoma.  Reporter- Larry H Bernstein, M.D.

4. Thymosin alpha1 and melanoma. Author, Editor: Tilda Barliya, Ph.D.

5. Exome sequencing of serous endometrial tumors shows recurrent somatic mutations in chromatin-remodeling and ubiquitin ligase complex genes. Reporter and Curator: Dr. Sudipta Saha, Ph.D.

6. How Genome Sequencing is Revolutionizing Clinical Diagnostics. Reporter: Aviva Lev-Ari, PhD, RN.

7. Issues in Personalized Medicine in Cancer: Intratumor Heterogeneity and Branched Evolution Revealed by Multiregion Sequencing. Curator and Reporter: Stephen J. Williams, Ph.D.

 

 

 

 

 

 

 

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Targeting Mitochondrial-bound Hexokinase for Cancer Therapy

Posted in CANCER BIOLOGY & Innovations in Cancer Therapy, Disease Biology, Small Molecules in Development of Therapeutic Drugs, tagged , , , , , , , , , on April 6, 2013| 9 Comments »

Targeting Mitochondrial-bound Hexokinase for Cancer Therapy

Author: Ziv Raviv, PhD

Article-7.3.4. Targeting Mitochondrial bound Hexokinase for Cancer Therapy

Mitochondria are recognized as essential for both life and death fates of cells. Mitochondria are the site where oxidative phosphorylation happens, the process that is responsible for the majority of energy production of the cell in the form of adenosine triphosphate (ATP) synthesis. Therefore mitochondria are considered as the main power station of the cell. On the other hand, both apoptotic and necrotic cell death may result from mitochondrial perturbation [1]. In cancer cells, mitochondria are different from those of normal cells by several aspects: (i) In cancer cells the mitochondrial membrane potential is higher than that of normal cells, (ii) there is expression modulation of permeability transition pore complex (PTPC) components which include the voltage-dependent anion channel (VDAC), the adenine nucleotide translocator (ANT), and cyclophilin D, and (iii) there are enhanced rates of glycolysis even in the presence of oxygen, a phenomena that is known as the Warburg effect [2]. In fact, many chemotherapeutic drugs induce mitochondrial-mediated apoptotic cell death (intrinsic apoptosis pathway) and act via mitochondrial perturbation, causing mitochondrial membrane permeability transition (MPT), membrane depolarization, osmotic swelling, and release of cytochrome c leading to cancer cell death.

Hexokinase (HK) is the initial enzyme of glycolysis that catalyzes the phosphorylation of glucose to glucose-6-phosphate (G6P), which is also the rate-limiting step in glycolysis and sequesters glucose inside the cells.  In cancer cells, HK (mainly HK-II) is overexpressed and found mostly bound to mitochondria through VDAC1  [3]. An enhanced expression of HK is found in aggressive tumors such as gliomas [4], and hepatomas [5]. HK overexpression, along with its glucose phosphorylation activity, is suggested to play a pivotal role in cancer cell growth rate and survival [6]. Thus, mitochondrial-bound HK overexpression may contribute to the Warburg effect by facilitating the access  to ATP, the substrate of HK [7]. In addition, as one of the hallmarks of cancer [8] is evading apoptotic cell death, owing in part to overexpression of anti-apoptotic proteins of the Bcl-2 family and that of HK, the elevated levels of mitochondria-bound HK in cancer cells contribute to the protection against mitochondria-mediated cell death [6].  All together, these characteristics make HK attractive target for cancer therapy.

Anti-cancer agents targeting HK-mitochondria interactions:

Jasmonates

The jasmonates plant stress hormones aside from their natural function against microbial pathogens in plants were also discovered to have toxic activities towards mammalian cancer cells. These activities consist of two important characteristics for anti-cancer drugs: high selectivity towards cancer cells, and the ability to act against drug resistant cancer cells [9]. The main mechanism of action of jasmonates–induced cancer cell death is suggested to involve direct mitochondrial perturbation. Methyl jasmonate (MJ) is able to reduce intracellular levels of ATP in various cancer cells, preceding cell death induction. Thus, the impaired ability of cancer cell mitochondria to generate ATP renders them more sensitive to the rapid ATP depletion induced by MJ. In addition, MJ induces mitochondrial membrane depolarization and cytochrome c release in cancer cells, as well as swelling and cytochrome c release in isolated mitochondria derived from cancer cells in a PTPC-mediated manner, but not of normal cells [10]. These findings demonstrate that the jasmonates selective toxicity towards cancer cells relies on the differential mitochondrial status of cancer cells vs. non-cancerous cells. Most relevant, it was clearly demonstrated that MJ binds specifically to HK and disrupts its interaction with mitochondrial VDAC1, leading to detachment of HK from the mitochondria followed by cytochrome c release and subsequent cell death [11]. The direct interaction of MJ with HK was demonstrated using real-time surface plasmon resonance (SPR).  In addition, it was demonstrated that the susceptibility of cancer cells and mitochondria to MJ  depends on the expression of HK and its mitochondrial association [11]. Therefore, MJ-induced HK detachment from mitochondria perturbs mitochondrial permeability and induce overall cellular energy crises, leading to cell death (see figure). Jasmonates thus describe for the first time of a cytotoxic mechanism based on direct interaction between an anti-cancer agent and HK. This finding may stimulate the development of a novel class of small anticancer compounds that inhibit the HK-VDAC1 interaction [12].

Image

VDAC1-based peptides

As described above, the HK association to mitochondria in cancer cells mediated through VDAC1 [13]. It has been shown that HK–VDAC1 interaction prevents induction of apoptosis in tumor-derived cells. Thus interfering with HK binding to VDAC1, promoting detachment of HK would form the basis for novel cancer treatment. Two main classes of agents might affect the HK-VDAC1 association: inhibitors of HK activity, or compounds that compete with VDAC1 for HK binding.

Detailed studies were performed in order to elucidate the domains on VDAC1 sequence that are essential for its interactions with HK.  These studies were based upon VDAC1 biochemical/functional structural prediction and the recently elucidated VDAC1 3D structure. By mutagenesis and functional studies, suspected domains on VDAC1 were examined as for their role in VDAC1-HK interactions [14]. According to these studies selected cell-penetrable VDAC1-based peptides were designed and were demonstrated to directly interact with purified HK in vitro and to detach HK bound to mitochondria isolated from tumor cells. Not only that, it was clearly demonstrated that these peptides are capable to selectively kill cancer cells while spearing normal cells [15], all together supporting the notion that interfering with the binding of HK to mitochondria by VDAC1-based peptides indeed may offer a novel strategy by which to induce selective cancer cell death.

Further directions

In order to evaluate the potential of using the HK-mitochondrial interactions as valid targets for cancer therapy, more steps are needed to be taken on the road. The selectiveness of this therapy relays on the fact that cancer cells bare much more mitochondrial-bound HK than normal cells, which might serve as an Achilles heel of the cancer cell. As peptides could be easily degraded in the plasma, the VDAC1-based peptides efficacy against cancer should be evaluated in vivo as well as their plasma stability should be examined. New generation and formulations of VDAC1-based peptides should be developed based upon research progress. As for jasmonates, their main deficiency is the need of using relatively high concentration (at the range of millimolar) to exert their action. Therefore, in order to develop valid jasmonate-based therapies, there is an urgent need for the development of jasmonate analogs that actually work in much lower dosage, with increased solubility, yet still effective and potent against cancer. Furthermore, it is not clear yet what is the exact domain on HK that MJ is interacting with. Elucidating the plausible interaction site(s) of MJ with HK would give the opportunity to design other small molecules directed to that specific HK domain with the hope to achieve more effective anti-cancer agents.

References

1. Newmeyer DD, Ferguson-Miller S (2003) Mitochondria: releasing power for life and unleashing the machineries of death. Cell 112 (4):481-490

2. Warburg O (1956) On the origin of cancer cells. Science 123 (3191):309-314

3. Pedersen PL, Mathupala S, Rempel A, Geschwind JF, Ko YH (2002) Mitochondrial bound type II hexokinase: a key player in the growth and survival of many cancers and an ideal prospect for therapeutic intervention. Biochim Biophys Acta 1555 (1-3):14-20

4. Pastorino JG, Hoek JB (2003) Hexokinase II: the integration of energy metabolism and control of apoptosis. Curr Med Chem 10 (16):1535-1551

5. Gelb BD, Adams V, Jones SN, Griffin LD, MacGregor GR, McCabe ER (1992) Targeting of hexokinase 1 to liver and hepatoma mitochondria. Proc Natl Acad Sci U S A 89 (1):202-206

6. Mathupala SP, Ko YH, Pedersen PL (2006) Hexokinase II: cancer’s double-edged sword acting as both facilitator and gatekeeper of malignancy when bound to mitochondria. Oncogene 25 (34):4777-4786

7. Pedersen PL (2007) Warburg, me and Hexokinase 2: Multiple discoveries of key molecular events underlying one of cancers’ most common phenotypes, the “Warburg Effect”, i.e., elevated glycolysis in the presence of oxygen. J Bioenerg Biomembr 39 (3):211-222

8. Hanahan D, Weinberg RA (2011) Hallmarks of cancer: the next generation. Cell 144 (5):646-674

9. Raviv Z, Cohen S, Reischer-Pelech D (2013) The anti-cancer activities of jasmonates. Cancer Chemother Pharmacol 71 (2):275-285

10. Rotem R, Heyfets A, Fingrut O, Blickstein D, Shaklai M, Flescher E (2005) Jasmonates: novel anticancer agents acting directly and selectively on human cancer cell mitochondria. Cancer Res 65 (5):1984-1993

11. Goldin N, Arzoine L, Heyfets A, Israelson A, Zaslavsky Z, Bravman T, Bronner V, Notcovich A, Shoshan-Barmatz V, Flescher E (2008) Methyl jasmonate binds to and detaches mitochondria-bound hexokinase. Oncogene 27 (34):4636-4643

12. Galluzzi L, Kepp O, Tajeddine N, Kroemer G (2008) Disruption of the hexokinase-VDAC complex for tumor therapy. Oncogene 27 (34):4633-4635

13. Shoshan-Barmatz V, Zakar M, Rosenthal K, Abu-Hamad S (2009) Key regions of VDAC1 functioning in apoptosis induction and regulation by hexokinase. Biochim Biophys Acta 1787 (5):421-430

14. Abu-Hamad S, Zaid H, Israelson A, Nahon E, Shoshan-Barmatz V (2008) Hexokinase -I protection against apoptotic cell death is mediated via interaction with the voltage-dependent anion channel-1: Mapping the site of binding. J Biol Chem 19:13482-13490

15. Arzoine L, Zilberberg N, Ben-Romano R, Shoshan-Barmatz V (2009) Voltage-dependent anion channel 1-based peptides interact with hexokinase to prevent its anti-apoptotic activity. J Biol Chem 284 (6):3946-3955.

pharmaceuticalintelligence.com

http://pharmaceuticalintelligence.com/2012/10/17/is-the-warburg-effect-the-cause-or-the-effect-of-cancer-a-21st-century-view/

http://pharmaceuticalintelligence.com/2012/09/01/mitochondria-and-cancer-an-overview/

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Personalized Medicine: Cancer Cell Biology and Minimally Invasive Surgery (MIS)

Posted in Bio Instrumentation in Experimental Life Sciences Research, Biological Networks, Gene Regulation and Evolution, Biomarkers & Medical Diagnostics, BioSimilars, CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Chemical Biology and its relations to Metabolic Disease, Chemical Genetics, Disease Biology, Small Molecules in Development of Therapeutic Drugs, FDA Regulatory Affairs, Genome Biology, Genomic Testing: Methodology for Diagnosis, Human Immune System in Health and in Disease, Liver & Digestive Diseases Research, Medical and Population Genetics, Personalized and Precision Medicine & Genomic Research, Pharmaceutical R&D Investment, Population Health Management, Genetics & Pharmaceutical, Regulated Clinical Trials: Design, Methods, Components and IRB related issues, Technology Transfer: Biotech and Pharmaceutical, tagged , , , , , , , on December 1, 2012| 9 Comments »

Personalized Medicine: Cancer Cell Biology and Minimally Invasive Surgery (MIS)

Curator: Aviva Lev-Ari, PhD, RN

Article-7.1.6. Personalized Medicine Cancer Cell Biology and Minimally Invasive Surgery (MIS

In the field of Cancer Research, Translational Medicine  will become Personalized Medicine when each of the cancer type, below will have a Genetic Marker allowing the Clinical Team to use the marker for:

  • prediction of Patient’s reaction to Drug induction
  • design of Clinical Trials to validate drug efficacy on small subset of patients predicted to react favorable to drug regimen, increasing validity and reliability
  • Genetical identification of patients at no need to have a drug administered if non sensitivity to the drug has been predicted

Current urgent need exists for Identification of Genetic Markers to predict Patient’s reaction to Drugs Induction for the following types of Cancer:

 

The executive task of the clinician remains to assess the differentiation in Tumor Response to Treatment.

Review of limitations for the current existing Tools used by clinicians in to be found in:

Brücher BLDM, Bilchik A, Nissan A, Avital I & Stojadinovic A. Can tumor response to therapy be predicted, thereby improving the selection of patients for cancer treatment?  Future Oncology 2012; 8(8): 903-906 , DOI 10.2217/fon.12.78 (doi:10.2217/fon.12.78)   The heterogeneity is a problem that will take at least another decade to unravel because of the number of signaling pathways and the crosstalk that is specifically at issue.

Future Oncology August 2012, Vol. 8, No. 8, Pages 903-906 ,

It is suggested that the new modality should be based on individualized histopathology as well as tumor molecular, genetic and functional characteristics, and individual patients’ characteristics. The new modality should be based on empirical evidence that translates into relevant and meaningful clinical outcome data.

Cancer is in particular a difficult to treat tissue type pathology. In “Tumor response criteria: are they appropriate?” that concern is addressed as follows:

“This becomes a conundrum of sorts in an era of ‘minimally invasive treatment’. One frequently encountered example is that of a patient with chronic gastric reflux and an ultrasound-staged T3N1 distal esophageal adenocarcinoma, who had complete sonographic tumor response to neoadjuvant chemoradiation. The physician may declare that, the tumor having disappeared, the patient requires no further treatment. The surgical oncologist recommends resection, recognizing the fact that up to 20% or more of these complete responders will have identifiable nests of tumor beyond the mucosal scar within the specimen – in other words: residual tumor. In other cases, patients with clinical, sonographic, functional (PET) and histopathological ‘complete’ tumor response to induction therapy experience recurrence within the first 2 years of resection, reminding us of the intricacy and enigma of tumor biology. We have yet to develop the tools needed to consistently delineate the response of a tumor to multimodality therapy.”

This described reality in the Oncology Operating Room is coupled with new trends in invasive treatment of tumor resection.

Minimally Invasive Surgery (MIS) vs. conventional surgery dissection applied to cancer tissue with the known pathophysiology of recurrence and remission cycles has its short term advantages. However, in many cases MIS is not the right surgical decision, yet, it is applied for a corollary of patient-centered care considerations. At present, facing the unknown of the future behavior of the tumor as its response to therapeutics bearing uncertainty related to therapy outcomes.

An increase in the desirable outcomes of MIS as a modality of treatment, will be strongly assisted in the future, with anticipated progress to be made in the field of Cancer Research, Translational Medicine and Personalized Medicine, when each of the cancer types, above,  will already have a Genetic Marker allowing the Clinical Team to use the marker(s) for:

  • prediction of Patient’s reaction to Drug induction
  • design of Clinical Trials to validate drug efficacy on small subset of patients predicted to react favorable to drug regimen, increasing validity and reliability
  • Genetical identification of patients at no need to have a drug administered if non sensitivity to the drug has been predicted by the genetic marker.

REFERENCES

Tumor response criteria: are they appropriate?

Björn LDM Brücher*1,2, Anton Bilchik2,3, Aviram Nissan2,4, Itzhak Avital2,5 & Alexander Stojadinovic2,6

 
Treatment for cure is not the endpoint, but the best that can be done is to extend the time of survival to a realistic long term goal and retain a quality of life.
 
Brücher BLDM, Piso P, Verwaal V et al. Peritoneal carcinomatosis: overview and basics. Cancer Invest.30(3),209–224 (2012).
 
Brücher BLDM, Swisher S, Königsrainer A et al. Response to preoperative therapy in upper gastrointestinal cancers. Ann. Surg. Oncol.16(4),878–886 (2009).
 
Miller AB, Hoogstraten B, Staquet M, Winkler A. Reporting results of cancer treatment. Cancer47(1),207–214 (1981).
 
 
 

Other research papers on Cancer and Cancer Therapeutics were published on this Scientific Web site as follows:

What can we expect of tumor therapeutic response?

PIK3CA mutation in Colorectal Cancer may serve as a Predictive Molecular Biomarker for adjuvant Aspirin therapy

Nanotechnology Tackles Brain Cancer

Response to Multiple Cancer Drugs through Regulation of TGF-β Receptor Signaling: a MED12 Control

Personalized medicine-based cure for cancer might not be far away

GSK for Personalized Medicine using Cancer Drugs needs Alacris systems biology model to determine the in silico effect of the inhibitor in its “virtual clinical trial”

Lung Cancer (NSCLC), drug administration and nanotechnology

Non-small Cell Lung Cancer drugs – where does the Future lie?

Cancer Innovations from across the Web

arrayMap: Genomic Feature Mining of Cancer Entities of Copy Number Abnormalities (CNAs) Data

How mobile elements in “Junk” DNA promote cancer. Part 1: Transposon-mediated tumorigenesis.

Cancer Genomics – Leading the Way by Cancer Genomics Program at UC Santa Cruz

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

mRNA interference with cancer expression

Search Results for ‘cancer’ on this web site

Cancer Genomics – Leading the Way by Cancer Genomics Program at UC Santa Cruz

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

Lipid Profile, Saturated Fats, Raman Spectrosopy, Cancer Cytology

mRNA interference with cancer expression

Pancreatic cancer genomes: Axon guidance pathway genes – aberrations revealed

Biomarker tool development for Early Diagnosis of Pancreatic Cancer: Van Andel Institute and Emory University

Is the Warburg Effect the cause or the effect of cancer: A 21st Century View?

Crucial role of Nitric Oxide in Cancer

Targeting Glucose Deprived Network Along with Targeted Cancer Therapy Can be a Possible Method of Treatment

 

See comment written for:

Knowing the tumor’s size and location, could we target treatment to THE ROI by applying…..

http://pharmaceuticalintelligence.com/2012/10/16/knowing-the-tumors-size-and-location-could-we-target-treatment-to-the-roi-by-applying-imaging-guided-intervention/

24 Responses

  1. GREAT work.

    I’ll read and comment later on

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    New warnings about 5-alpha-reductase inhibitors and aggressive prostate cancer.

  3. Promising technique.

    INCORE pointed out in detail about the general problem judging response and the stil missing quality in standardization:

    http://www.futuremedicine.com/doi/abs/10.2217/fon.12.78?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dwww.ncbi.nlm.nih.gov

    I did research in response evaluation and prediction for about 15y now and being honest: neither the clinical, nor the molecular biological data proved significant benefit in changing a strategy in patient diagnosis and / or treatment. I would state: this brings us back on the ground and not upon the sky. Additionally it means: we have to ´work harder on that and the WHO has to take responsibility: clinicians use a reponse classification without knowing, that this is just related to “ONE” experiment from the 70′s and that this experiment never had been rescrutinized (please read the Editorial I provided – we use a clinical response classification since more than 30 years worldwide (Miller et al. Cancer 1981) but it is useless !

  4. Dr. BB

    Thank you for your comment.
    Dr. Nir will reply to your comment.
    Regarding the Response Classification in use, it seems that the College of Oncology should champion a task force to revisit the Best Practice in use in this domain and issue a revised version or a new effort for a a new classification system for Clinical Response to treatment in Cancer.

  5. I’m sorry that I was looking for this paper again earlier and didn’t find it. I answered my view on your article earlier.

    This is a method demonstration, but not a proof of concept by any means. It adds to the cacophany of approaches, and in a much larger study would prove to be beneficial in treatment, but not a cure for serious prostate cancer because it is unlikely that it can get beyond the margin, and also because there is overtreatment at the cutoff of PSA at 4.0. There is now a proved prediction model that went to press some 4 months ago. I think that the pathologist has to see the tissue, and the standard in pathology now is for any result that is cancer, two pathologist or a group sitting together should see it. It’s not an easy diagnosis.

    Björn LDM Brücher, Anton Bilchik, Aviram Nissan, Itzhak Avital, & Alexander Stojadinovic. Tumor response criteria: are they appropriate? Future Oncol. (2012) 8(8), 903–906. 10.2217/FON.12.78. ISSN 1479-6694.

    ..Tumor heterogeneity is a ubiquitous phemomenon. In particular, there are important differences among the various types of gastrointestinal (GI) cancers in terms of tumor biology, treatment response and prognosis.

    ..This forms the principal basis for targeted therapy directed by tumor-specific testing at either the gene or protein level. Despite rapid advances in our understanding of targeted therapy for GI cancers, the impact on cancer survival has been marginal.

    ..Can tumor response to therapy be predicted, thereby improving the selection of patients for cancer treatment?

    ..In 2000 theNCI with the European Association for Research and Treatment of Cancer, proposed a replacement of 2D measurement with a decrease in the largest tumor diameter by 30% in one dimension. Tumor response as defined would translate into a 50% decrease for a spherical lesion

    ..We must rethink how we may better determine treatment response in a reliable, reproducible way that is aimed at individualizing the therapy of cancer patients.

    ..we must change the tools we use to assess tumor response. The new modality should be based on empirical evidence that translates into relevant and meaningful clinical outcome data.

    ..This becomes a conundrum of sorts in an era of ‘minimally invasive treatment’.

    ..integrated multidisciplinary panel of international experts – not sure that that will do it

    Several years ago i heard Stamey present the totality of his work at Stanford, with great disappointment over hsPSA that they pioneered in. The outcomes were disappointing.

    I had published a review of all of our cases reviewed for 1 year with Marguerite Pinto.
    There’s a reason that the physicians line up outside of her office for her opinion.
    The review showed that a PSA over 24 ng/ml is predictive of bone metastasis. Any result over 10 was as likely to be prostatitis, BPH or cancer.

    I did an ordinal regression in the next study with Gustave Davis using a bivariate ordinal regression to predict lymph node metastasis using the PSA and the Gleason score. It was better than any univariate model, but there was no followup.

    I reviewed a paper for Clin Biochemistry (Elsevier) on a new method for PSA, very different than what we are familiar with. It was the most elegant paper I have seen in the treatment of the data. The model could predict post procedural time to recurrence to 8 years.

    • I hope we are in agreement on the fact that imaging guided interventions are needed for better treatment outcome. The point I’m trying to make in this post is that people are investing in developing imaging guided intervention and it is making progress.

      Over diagnosis and over treatment is another issue altogether. I think that many of my other posts are dealing with that.

  6. Tumor response criteria: are they appropriate?
    Future Oncology 2012; 8(8): 903-906 , DOI 10.2217/fon.12.78 (doi:10.2217/fon.12.78)
    Björn LDM Brücher, Anton Bilchik, Aviram Nissan, Itzhak Avital & Alexander Stojadinovic
    Tumor heterogeneity is a problematic because of differences among the metabolic variety among types of gastrointestinal (GI) cancers, confounding treatment response and prognosis.
    This is in response to … a group of investigators from Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada who evaluate the feasibility and safety of magnetic resonance (MR) imaging–controlled transurethral ultrasound therapy for prostate cancer in humans. Their study’s objective was to prove that using real-time MRI guidance of HIFU treatment is possible and it guarantees that the location of ablated tissue indeed corresponds to the locations planned for treatment.
    1. There is a difference between expected response to esophageal or gastric neoplasms both biologically and in expected response, even given variability within a class. The expected time to recurrence is usually longer in the latter case, but the confounders are – age at time of discovery, biological time of detection, presence of lymph node and/or distant metastasis, microscopic vascular invasion.
    2. There is a long latent period in abdominal cancers before discovery, unless a lesion is found incidentally in surgery for another reason.
    3. The undeniable reality is that it is not difficult to identify the main lesion, but it is difficult to identify adjacent epithelium that is at risk (transitional or pretransitional). Pathologists have a very good idea about precancerous cervical neoplasia.

    The heterogeneity rests within each tumor and between the primary and metastatic sites, which is expected to be improved by targeted therapy directed by tumor-specific testing. Despite rapid advances in our understanding of targeted therapy for GI cancers, the impact on cancer survival has been marginal.

    The heterogeneity is a problem that will take at least another decade to unravel because of the number of signaling pathways and the crosstalk that is specifically at issue.

    I must refer back to the work of Frank Dixon, Herschel Sidransky, and others, who did much to develop a concept of neoplasia occurring in several stages – minimal deviation and fast growing. These have differences in growth rates, anaplasia, and biochemical. This resembles the multiple “hit” theory that is described in “systemic inflammatory” disease leading to a final stage, as in sepsis and septic shock.
    In 1920, Otto Warburg received the Nobel Prize for his work on respiration. He postulated that cancer cells become anaerobic compared with their normal counterpart that uses aerobic respiration to meet most energy needs. He attributed this to “mitochondrial dysfunction. In fact, we now think that in response to oxidative stress, the mitochondrion relies on the Lynen Cycle to make more cells and the major source of energy becomes glycolytic, which is at the expense of the lean body mass (muscle), which produces gluconeogenic precursors from muscle proteolysis (cancer cachexia). There is a loss of about 26 ATP ~Ps in the transition.
    The mitochondrial gene expression system includes the mitochondrial genome, mitochondrial ribosomes, and the transcription and translation machinery needed to regulate and conduct gene expression as well as mtDNA replication and repair. Machinery involved in energetics includes the enzymes of the Kreb’s citric acid or TCA (tricarboxylic acid) cycle, some of the enzymes involved in fatty acid catabolism (β-oxidation), and the proteins needed to help regulate these systems. The inner membrane is central to mitochondrial physiology and, as such, contains multiple protein systems of interest. These include the protein complexes involved in the electron transport component of oxidative phosphorylation and proteins involved in substrate and ion transport.
    Mitochondrial roles in, and effects on, cellular homeostasis extend far beyond the production of ATP, but the transformation of energy is central to most mitochondrial functions. Reducing equivalents are also used for anabolic reactions. The energy produced by mitochondria is most commonly thought of to come from the pyruvate that results from glycolysis, but it is important to keep in mind that the chemical energy contained in both fats and amino acids can also be converted into NADH and FADH2 through mitochondrial pathways. The major mechanism for harvesting energy from fats is β-oxidation; the major mechanism for harvesting energy from amino acids and pyruvate is the TCA cycle. Once the chemical energy has been transformed into NADH and FADH2 (also discovered by Warburg and the basis for a second Nobel nomination in 1934), these compounds are fed into the mitochondrial respiratory chain.
    The hydroxyl free radical is extremely reactive. It will react with most, if not all, compounds found in the living cell (including DNA, proteins, lipids and a host of small molecules). The hydroxyl free radical is so aggressive that it will react within 5 (or so) molecular diameters from its site of production. The damage caused by it, therefore, is very site specific. The reactions of the hydroxyl free radical can be classified as hydrogen abstraction, electron transfer, and addition.
    The formation of the hydroxyl free radical can be disastrous for living organisms. Unlike superoxide and hydrogen peroxide, which are mainly controlled enzymatically, the hydroxyl free radical is far too reactive to be restricted in such a way – it will even attack antioxidant enzymes. Instead, biological defenses have evolved that reduce the chance that the hydroxyl free radical will be produced and, as nothing is perfect, to repair damage.
    Currently, some endogenous markers are being proposed as useful measures of total “oxidative stress” e.g., 8-hydroxy-2’deoxyguanosine in urine. The ideal scavenger must be non-toxic, have limited or no biological activity, readily reach the site of hydroxyl free radical production (i.e., pass through barriers such as the blood-brain barrier), react rapidly with the free radical, be specific for this radical, and neither the scavenger nor its product(s) should undergo further metabolism.
    Nitric oxide has a single unpaired electron in its π*2p antibonding orbital and is therefore paramagnetic. This unpaired electron also weakens the overall bonding seen in diatomic nitrogen molecules so that the nitrogen and oxygen atoms are joined by only 2.5 bonds. The structure of nitric oxide is a resonance hybrid of two forms.
    In living organisms nitric oxide is produced enzymatically. Microbes can generate nitric oxide by the reduction of nitrite or oxidation of ammonia. In mammals nitric oxide is produced by stepwise oxidation of L-arginine catalyzed by nitric oxide synthase (NOS). Nitric oxide is formed from the guanidino nitrogen of the L-arginine in a reaction that consumes five electrons and requires flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN) tetrahydrobiopterin (BH4), and iron protoporphyrin IX as cofactors. The primary product of NOS activity may be the nitroxyl anion that is then converted to nitric oxide by electron acceptors.
    The thiol-disulfide redox couple is very important to oxidative metabolism. GSH is a reducing cofactor for glutathione peroxidase, an antioxidant enzyme responsible for the destruction of hydrogen peroxide. Thiols and disulfides can readily undergo exchange reactions, forming mixed disulfides. Thiol-disulfide exchange is biologically very important. For example, GSH can react with protein cystine groups and influence the correct folding of proteins, and it GSH may play a direct role in cellular signaling through thiol-disulfide exchange reactions with membrane bound receptor proteins (e.g., the insulin receptor complex), transcription factors (e.g., nuclear factor κB), and regulatory proteins in cells. Conditions that alter the redox status of the cell can have important consequences on cellular function.
    So the complexity of life is not yet unraveled.

    Can tumor response to therapy be predicted, thereby improving the selection of patients for cancer treatment?
    The goal is not just complete response. Histopathological response seems to be related post-treatment histopathological assessment but it is not free from the challenge of accurately determining treatment response, as this method cannot delineate whether or not there are residual cancer cells. Functional imaging to assess metabolic response by 18-fluorodeoxyglucose PET also has its limits, as the results are impacted significantly by several variables:

    • tumor type
    • sizing
    • doubling time
    • anaplasia?
    • extent of tumor necrosis
    • type of antitumor therapy and the time when response was determined.
    The new modality should be based on individualized histopathology as well as tumor molecular, genetic and functional characteristics, and individual patients’ characteristics, a greater challenge in an era of ‘minimally invasive treatment’.
    This listing suggests that for every cancer the following data has to be collected (except doubling time). If there are five variables, the classification based on these alone would calculate to be very sizable based on Eugene Rypka’s feature extraction and classification. But looking forward, time to remission and disease free survival are additionally important. Treatment for cure is not the endpoint, but the best that can be done is to extend the time of survival to a realistic long term goal and retain a quality of life.

    Brücher BLDM, Piso P, Verwaal V et al. Peritoneal carcinomatosis: overview and basics. Cancer Invest.30(3),209–224 (2012).
    Brücher BLDM, Swisher S, Königsrainer A et al. Response to preoperative therapy in upper gastrointestinal cancers. Ann. Surg. Oncol.16(4),878–886 (2009).
    Miller AB, Hoogstraten B, Staquet M, Winkler A. Reporting results of cancer treatment. Cancer47(1),207–214 (1981).
    Therasse P, Arbuck SG, Eisenhauer EA et al. New guidelines to evaluate the response to treatment in solid tumors. European Organization for Research and Treatment of Cancer, National Cancer Institute of the United States, National Cancer Institute of Canada. J. Natl Cancer Inst.92(3),205–216 (2000).
    Brücher BLDM, Becker K, Lordick F et al. The clinical impact of histopathological response assessment by residual tumor cell quantification in esophageal squamous cell carcinomas. Cancer106(10),2119–2127 (2006).

    • Dr. Larry,

      Thank you for this comment.

      Please carry it as a stand alone post, Dr. Ritu will refer to it and reference it in her FORTHCOMING pst on Tumor Response which will integrate multiple sources.

      Please execute my instruction

      Thank you

    • Thank you Larry for this educating comment. It explains very well why the Canadian investigators did not try to measure therapy response!

      What they have demonstrated is the technological feasibility of coupling a treatment device to an imaging device and use that in order to guide the treatment to the right place.

      the issue of “choice of treatment” to which you are referring is not in the scope of this publication.
      The point is: if one treatment modality can be guided, other can as well! This should encourage others, to try and develop imaging-based treatment guidance systems.

  7. The crux of the matter in terms of capability is that the cancer tissue, adjacent tissue, and the fibrous matrix are all in transition to the cancerous state. It is taught to resect leaving “free margin”, which is better aesthetically, and has had success in breast surgery. The dilemma is that the patient may return, but how soon?

    • Correct. The philosophy behind lumpectomy is preserving quality of life. It was Prof. Veronesi (IEO) who introduced this method 30 years ago noticing that in the majority of cases, the patient will die from something else before presenting recurrence of breast cancer..

      It is well established that when the resection margins are declared by a pathologist (as good as he/she could be) as “free of cancer”, the probability of recurrence is much lower than otherwise.

  8. Dr. Larry,

    To assist Dr. Ritu, PLEASE carry ALL your comments above into a stand alone post and ADD to it your comment on my post on MIS

    Thank you

  9. Great post! Dr. Nir, can the ultrasound be used in conjunction with PET scanning as well to determine a spatial and functional map of the tumor. With a disease like serous ovarian cancer we typically see an intraperitoneal carcimatosis and it appears that clinicians are wanting to use fluorogenic probes and fiberoptics to visualize the numerous nodules located within the cavity Also is the technique being used mainy for surgery or image guided radiotherapy or can you use this for detecting response to various chemotherapeutics including immunotherapy.

    • Ultrasound can and is actually used in conjunction with PET scanning in many cases. The choice of using ultrasound is always left to the practitioner! Being a non-invasive, low cost procedure makes the use of ultrasound a non-issue. The down-side is that because it is so easy to access and operate, nobody bothers to develop rigorous guidelines about using it and the benefits remains the property of individuals.

      In regards to the possibility of screening for ovarian cancer and characterising pelvic masses using ultrasound I can refer you to scientific work in which I was involved:

      1. VAES (E.), MANCHANDA (R), AUTIER, NIR (R), NIR (D.), BLEIBERG (H.), ROBERT (A.), MENON (U.). Differential diagnosis of adnexal masses: Sequential use of the Risk of Malignancy Index and a novel computer aided diagnostic tool. Published in Ultrasound in Obstetrics & Gynecology. Issue 1 (January). Vol. 39. Page(s): 91-98.

      2. VAES (E.), MANCHANDA (R), NIR (R), NIR (D.), BLEIBERG (H.), AUTIER (P.), MENON (U.), ROBERT (A.). Mathematical models to discriminate between benign and malignant adnexal masses: potential diagnostic improvement using Ovarian HistoScanning. Published in International Journal of Gynecologic Cancer (IJGC). Issue 1. Vol. 21. Page(s): 35-43.

      3. LUCIDARME (0.), AKAKPO (J.-P.), GRANBERG (S.), SIDERI (M.), LEVAVI (H.), SCHNEIDER (A.), AUTIER (P.), NIR (D.), BLEIBERG (H.). A new computer aided diagnostic tool for non-invasive characterisation of malignant ovarian masses: Results of a multicentre validation study. Published in European Radiology. Issue 8. Vol. 20. Page(s): 1822-1830.

      Dror Nir, PhD
      Managing partner

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  10. totally true and i am very thankfull for these briliant comments.

    Remember: 10years ago: every cancer researcher stated: “look at the tumor cells only – forget the stroma”. The era of laser-captured tumor-cell dissection started. Now , everyone knows: it is a system we are looking at and viewing and analyzing tumor cells only is really not enough.

    So if we would be honest, we would have to declare, that all data, which had been produced 13-8years ago, dealing with laser capture microdissection, that al these data would need a re-scrutinization, cause the influence of the stroma was “forgotten”. I ‘d better not try thinking about the waisted millions of dollars.

    If we keep on being honest: the surgeon looks at the “free margin” in a kind of reductionable model, the pathologist is more the control instance. I personally see the pathologist as “the control instance” of surgical quality. Therefore, not the wish of the surgeon is important, the objective way of looking into problems or challenges. Can a pathologist always state, if a R0-resection had been performed ?

    The use of the Resectability Classification:
    There had been many many surrogate marker analysis – nothing new. BUT never a real substantial well tought through structured analysis had been done: mm by mm by mm by mm and afterwards analyzing that by a ROC analysis. BUt against which goldstandard ? If you perform statistically a ROC analysis – you need a golstandard to compare to. Therefore what is the real R0-resectiòn? It had been not proven. It just had been stated in this or that tumor entity that this or that margin with this margin free mm distance or that mm distance is enough and it had been declared as “the real R0-classification”. In some organs it is very very difficult and we all (surgeons, pathologists, clinicians) that we always get to the limit, if we try interpretating the R-classification within the 3rd dimension. Often it is just declared and stated.

    Otherwise: if lymph nodes are negative it does not mean, lymph nodes are really negative, cause up to 38% for example in upper GI cancers have histological negative lymph nodes, but immunohistochemical positive lymph nodes. And this had been also shown by Stojadinovic at el analyzing the ultrastaging in colorectal cancer. So the 4th dimension of cancer – the lymph nodes / the lymphatic vessel invasion are much more important than just a TNM classification, which unfortunately does often not reflect real tumor biology.

    AS we see: cancer has multifactorial reasons and it is necessary taking the challenge performing high sophisticated research by a multifactorial and multidisciplinary manner.

    Again my deep and heartly thanks for that productive and excellent discussion !

    • Dr. BB,

      Thank you for your comment.

      Multidisciplinary perspectives have illuminated the discussion on the pages of this Journal.

      Eager to review Dr. Ritu’s forthcoming paper – the topic has a life of its own and is embodied in your statement:

      “the 4th dimension of cancer – the lymph nodes / the lymphatic vessel invasion are much more important than just a TNM classification, which unfortunately does often not reflect real tumor biology.”

    • Thank you BB for your comment. You have touched the core limitation of healthcare professionals: how do we know that we know!

      Do we have a reference to each of the test we perform?

      Do we have objective and standardise quality measures?

      Do we see what is out-there or are we imagining?

      The good news: Everyday we can “think” that we learned something new. We should be happy with that, even if it is means that we learned that yesterday’s truth is not true any-more and even if we are likely to be wrong again…:)

      But still, in the last decades, lots of progress was made….

  11. Dr. Nir,
    I thoroughly enjoyed reading your post as well as the comments that your post has attracted. There were different points of view and each one has been supported with relevant examples in the literature. Here are my two cents on the discussion:
    The paper that you have discussed had the objective of finding out whether real-time MRI guidance of treatment was even possible and if yes, and also if the treatment could be performed in accurate location of the ROI? The data reveals they were pretty successful in accomplishing their objective and of course that gives hope to the imaging-based targeted therapies.
    Whether the ROI is defined properly and if it accounts for the real tumor cure, is a different question. Role of pathologists and the histological analysis they bring about to the table cannot be ruled out, and the absence of a defined line between the tumor and the stromal region in the vicinity is well documented. However, that cannot rule out the value and scope of imaging-based detection and targeted therapy. After all, it is seminal in guiding minimally invasive surgery. As another arm of personalized medicine-based cure for cancer, molecular biologists at MD Anderson have suggested molecular and genetic profiling of the tumor to determine genetic aberrations on the basis of which matched-therapy could be recommended to patients. When phase I trial was conducted, the results were obtained were encouraging and the survival rate was better in matched-therapy patients compared to unmatched patients. Therefore, everytime there is more to consider when treating a cancer patient and who knows a combination of views of oncologists, pathologists, molecular biologists, geneticists, surgeons would device improvised protocols for diagnosis and treatment. It is always going to be complicated and generalizations would never give an answer. Smart interpretations of therapies – imaging-based or others would always be required!

    Ritu

    • Dr. Nir,
      One of your earlier comments, mentioned the non invasiveness of ultrasound, thus, it’s prevalence in use for diagnosis.

      This may be true for other or all areas with the exception of Mammography screening. In this field, an ultrasound is performed only if a suspected area of calcification or a lump has been detected in the routine or patient-initiated request for ad hoc mammography secondery to patient complain of pain or patient report of suspected lump.

      Ultrasound in this field repserents ascalation and two radiologists review.

      It in routine use for Breast biopsy.

    • Thanks Ritu for this supporting comment. The worst enemy of finding solutions is doing nothing while using the excuse of looking for the “ultimate solution” . Personally, I believe in combining methods and improving clinical assessment based on information fusion. Being able to predict, and then timely track the response to treatment is a major issue that affects survival and costs!

Judging the ‘Tumor response’-there is more food for thought

http://pharmaceuticalintelligence.com/2012/12/04/judging-the-tumor-response-there-is-more-food-for-thought/

13 Responses

  1. Dr. Sanexa
    you have brought up an interesting and very clinically relevant point: what is the best measurement of response and 2) how perspectives among oncologists and other professionals differ on this issues given their expertise in their respective subspecialties (immunologist versus oncologist. The advent of functional measurements of tumors (PET etc.) seems extremely important in the therapeutic use AND in the development of these types of compounds since usually a response presents (in cases of solid tumors) as either a lack of growth of the tumor or tumor shrinkage. Did the authors include an in-depth discussion of the rapidity of onset of resistance with these types of compounds?
    Thanks for the posting.

  2. Dr. Williams,
    Thanks for your comment on the post. The editorial brings to attention a view that although PET and other imaging methods provide vital information on tumor growth, shrinkage in response to a therapy, however, there are more aspects to consider including genetic and molecular characteristics of tumor.
    It was an editorial review and the authors did not include any in-depth discussion on the rapidity of onset of resistance with these types of compounds as the focus was primarily on interpreting tumor response.
    I am glad you found the contents of the write-up informative.
    Thanks again!
    Ritu

  3. Thank you for your wonderful comment and interpretation. Dr.Sanexa made a brilliant comment.

    May I allow myself putting my finger deeper into this wound ? Cancer patients deserve it.

    It had been already pointed out by international experts from Munich, Tokyo, Hong-Kong and Houston, dealing with upper GI cancer, that the actual response criteria are not appropriate and moreover: the clinical response criteria in use seem rather to function as an alibi, than helping to differentiate and / or discriminate tumor biology (Ann Surg Oncol 2009):

    http://www.ncbi.nlm.nih.gov/pubmed/19194759

    The response data in a phase-II-trial (one tumor entity, one histology, one treatment, one group) revealed: clinical response evaluation according to the WHO-criteria is not appropriate to determine response:

    http://www.ncbi.nlm.nih.gov/pubmed/15498642

    Of course, there was a time, when it seemed to be useful and this also has to be respected.

    There is another challenge: using statistically a ROC and resulting in thresholds. This was, is and always be “a clinical decision only” and not the decision of the statistician. The clinician tells the statistician, what decision, he wants to make – the responsibility is enormous. Getting back to the roots:
    After the main results of the Munich-group had been published 2001 (Ann Surg) and 2004 (J Clin Oncol):

    http://www.ncbi.nlm.nih.gov/pubmed/11224616

    http://www.ncbi.nlm.nih.gov/pubmed/14990646

    the first reaction in the community was: to difficult, can’t be, not re-evaluated, etc.. However, all evaluated cut-offs / thresholds had been later proven to be the real and best ones by the MD Anderson Cancer Center in Houston, Texas. Jaffer Ajani – a great and critical oncologist – pushed that together with Steve Swisher and they found the same results. Than the upper GI stakeholders went an uncommon way in science: they re-scrutinized their findings. Meanwhile the Goldstandard using histopathology as the basis-criterion had been published in Cancer 2006.

    http://www.ncbi.nlm.nih.gov/pubmed/16607651

    Not every author, who was at the authorlist in 2001 and 2004 wanted to be a part of this analysis and publication ! Why ? Everyone should judge that by himself.

    The data of this analysis had been submitted to the New England Journal of Medicine. In the 2nd review stage process, the manuscript was rejected. The Ann Surg Oncol accepted the publication: the re-scrutinized data resulted in another interesting finding: in the future maybe “one PET-scan” might be appropriate predicting the patient’s response.

    Where are we now ?

    The level of evidence using the response criteria is very low: Miller’s (Cancer 1981) publication belonged to ”one single” experiment from Moertel (Cancer 1976). During that time, there was no definition of “experiences” rather than “oncologists”. These terms had not been in use during that time.

    Additionally they resulted in a (scientifically weak) change of the classification, published by Therasse (J Natl Cancer Inst 2000). Targeted therapy did not result in a change so far. In 2009, the international upper GI experts sent their publication of the Ann Surg Oncol 2009 to the WHO but without any kind of reaction.

    Using molecular biological predictive markers within the last 10years all seem to have potential.

    http://www.ncbi.nlm.nih.gov/pubmed/20012971

    http://www.ncbi.nlm.nih.gov/pubmed/18704459

    http://www.ncbi.nlm.nih.gov/pubmed/17940507

    http://www.ncbi.nlm.nih.gov/pubmed/17354029

    But, experts are aware: the real step breaking barriers had not been performed so far. Additionally, it is very important in trying to evaluate and / predict response, that not different tumor entities with different survival and tumor biology are mixed together. Those data are from my perspective not helpful, but maybe that is my own Bias (!) of my view.

    INCORE, the International Consortium of Research Excellence of the Theodor-Billroth-Academy, was invited publishing the Editorial in Future Oncology 2012. The consortium pointed out, that living within an area of ‘prove of principle’ and also trying to work out level of evidence in medicine, it is “the duty and responsibility” of every clinician, but also of the societies and institutions, also of the WHO.

    Complete remission is not the only goal, as experts dealing with ‘response-research’ are aware. It is so frustrating for patients and clinicians: there is a rate of those patients with complete remission, who develop early recurrence ! This reflects, that complete remission cannot function as the only criterion describing response !

    Again, my heartly thanks, that Dr.Sanexa discussed this issue in detail.
    I hope, I found the way explaining the way of development and evaluating response criteria properly and in a differentiated way of view. From the perspective of INCORE:

    “an interdisciplinary initiative with all key stake¬holders and disciplines represented is imperative to make predictive and prognostic individualized tumor response assessment a modern-day reality. The integrated multidisciplinary panel of international experts need to define how to leverage existing data, tissue and testing platforms in order to predict individual patient treatment response and prognosis.”

  4. Dr. Brucher,

    First of all thanks for expressing your views on the ‘tumor response’ in a comprehensive way. You are the first author of the editorial review one of the prominent people who has taken part in the process of defining tumor response and I am glad that you decided to write a comment on the writeup.
    The topic has been explained well in an immaculate manner and that it further clarifies the need for the perfect markers that would be able to evaluate and predict tumor response. There are, as you mentioned, some molecular markers available including VEGF, cyclins, that have been brought to focus in the context of squamous cell carcinoma.

    It would be great if you could be the guest author for our blog and we could publish your opinion (comment on this blog post) as a separate post. Please let us know if it is OK with you.

    Thanks again for your comment
    Ritu

  5. Thank you all to the compelling discussions, above.

    Please review the two sources on the topic I placed at the bottom of the post, above as post on this Scientific Journal,

    All comments made to both entries are part of thisvdiscussion, I am referring to Dr. Nir’s post on size of tumor, to BB comment to Nir’s post, to Larry’ Pathologist view on Tumors and my post on remission and minimally invasive surgery (MIS).

    Great comments by Dr. Williams, BB and wonderful topic exposition by Dr. Ritu.

  6. Aviva,
    Thats a great idea. I will combine all sources referred by you, the post on tumor imaging by Dr. Nir and the comments made on the these posts including Dr. Brucher’s comments in a new posts.
    Thanks
    Ritu

    • Great idea, ask Larry, he has written two very long important comments on this topic, one on Nir’s post and another one, ask him where, if it is not on MIS post. GREAT work, Ritu, integration is very important. Dr, Williams is one of our Gems.

    • Assessing tumour response it is not an easy task!Because tumours don’t change,but happilly our knowlege(about them) does really change,is everchanging(thans god!).In the past we had the Recist Criteria,then the Modified Recist Criteria,becausa of Gist and other tumors.At this very moment,these are clearly insuficient.We do need more ,new validated facing the reality of nowadays.A great,enormoust post Dr Ritu!Congratulations!

 

 

 

 

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Prostate Cancer Cells: Histone Deacetylase Inhibitors Induce Epithelial-to-Mesenchymal Transition

Posted in Bio Instrumentation in Experimental Life Sciences Research, Biological Networks, Gene Regulation and Evolution, BioSimilars, CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Health Economics and Outcomes Research, Pharmaceutical Analytics, Stem Cells for Regenerative Medicine, tagged , , , , , , , , , , , , , , , , , , , , , , , , , , on November 30, 2012| 21 Comments »

Histone Deacetylase Inhibitors Induce Epithelial-to-Mesenchymal Transition in Prostate Cancer Cells(1)

Screen Shot 2021-07-19 at 7.44.44 PM

Word Cloud By Danielle Smolyar

Authors: Dejuan Kong, Aamir Ahmad, Bin Bao, Yiwei Li, Sanjeev Banarjee, Fazlul H. Sarkar, Wayne State University School of Medicine

Reporter-Curator: Stephen J. Williams, Ph.D.

Clinically, there has not been much success in treating solid tumors with histone deacetylase inhibitors (HDACi). Histone acetylation and deacetylation play an important role in transcriptional regulation of genes and increased activity is associated with many cancers, therefore it was thought that HDAC inhibition might be fruitful as a therapy.  There have been several phase I and II clinical trials using HDACi for treatment of various malignancies, including hematological and solid malignancies(2), with most success seen in hematologic malignancies such as cutaneous T-cell lymphoma and peripheral T-cell lymphoma and little or no positive outcome with solid tumors.  Many mechanisms of resistance to HDACi in solid tumors have been described, most of which are seen with other chemotherapeutics such as increased multidrug resistance gene MDR1, increased anti-apoptotic proteins and activation of cell survival pathways(3).

A report in PLOS One by Dr. Dejuan Kong, Dr. Fazlul Sarkar, and colleagues from Wayne State University School of Medicine, demonstrate another possible mechanism of resistance to HDACi in prostate cancer, by induction of the epithelial-to-mesenchymal transition (EMT), which has been associated with the development of resistance to chemotherapies in other malignancies of epithelial origin(4,5).

EMT is an important differentiation process in embryogenesis and felt to be important in progression of cancer.  Epithelial cells will acquire a mesenchymal morphology (on plastic this looks like a cuboidal epithelial cell gaining a more flattened, elongated, tri-corner morphology; see paper Figure 1) and down-regulate epithelial markers such as cytokeratin, up-regulation of mesenchymal markers, increased migration and invasiveness in standard assays, and increased resistance to chemotherapeutics, and similarity to cancer stem cells(6-10).

ImageFigure 1. HDACis led to the induction of EMT phemotype. (A and B) PC3 cells treated with TSA and SAHA for 24 h at indicated doses.  The photomicrographs of PC3 cells treated with TSA and SAHA exhibited a fibroblastic-type phenotype, while cells treated with DMAO control displayed rounded epithelial cell morphology (original magnification, x 100). (C) Treated PC3 cells show increased mesenchymal markers vimentin and ZEB1 and F-actin reorganization.  Figure taken from Kong, D., Ahmad, A., Bao, B., Li, Y., Banerjee, S., and Sarkar, F. H. (2012) PloS one 7, e45045

In this study the authors found that treatment of prostate carcinoma cells with two different HDACis (trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA)) induced EMT phenotype mediated through up-regulation of transcription factors ZEB1, ZEB2 and Slug, increased expression of mesenchymal markers vimentin, N-cadherin and fibronectin by promoting histone 3 acetylation on gene promoters.  In addition TSA increased the stem cell markers Sox2 and Nanog with concomitant EMT morphology and increased cell motility.

Below is the abstract of this paper(1):

ABSTRACT

Clinical experience of histone deacetylase inhibitors (HDACIs) in patients with solid tumors has been disappointing; however, the molecular mechanism of treatment failure is not known. Therefore, we sought to investigate the molecular mechanism of treatment failure of HDACIs in the present study. We found that HDACIs Trichostatin A (TSA) and Suberoylanilide hydroxamic acid (SAHA) could induce epithelial-to-mesenchymal transition (EMT) phenotype in prostate cancer (PCa) cells, which was associated with changes in cellular morphology consistent with increased expression of transcription factors ZEB1, ZEB2 and Slug, and mesenchymal markers such as vimentin, N-cadherin and Fibronectin. CHIP assay showed acetylation of histone 3 on proximal promoters of selected genes, which was in part responsible for increased expression of EMT markers. Moreover, TSA treatment led to further increase in the expression of Sox2 and Nanog in PCa cells with EMT phenotype, which was associated with cancer stem-like cell (CSLC) characteristics consistent with increased cell motility. Our results suggest that HDACIs alone would lead to tumor aggressiveness, and thus strategies for reverting EMT-phenotype to mesenchymal-to-epithelial transition (MET) phenotype or the reversal of CSLC characteristics prior to the use of HDACIs would be beneficial to realize the value of HDACIs for the treatment of solid tumors especially PCa.

Highlights of the research include:

  • TSA and SAHA induce morphologic changes  in prostate carcinoma LNCaP and PC3 cells related to EMT by microscopy as well as accumulation of mesenchymal markers ZEB1, vimentin, and F-actin reorganization shown by immunofluorescence microscopy and increased expression of these markers shown by real-time PCR
  • Western blotting showed TSA treatment resulted in hyperacetyulation of histone 3 whi8le CHIP analysis revealed increased histone 3 acetylation on the promoters of vimentin, ZEB2, Slug, and MMP2
  • Western analysis revealed that HDACi not only induced EMT but increased the expression of cancer stem cell markers associated with increased motility such as Sox2 and Nanog.  Increased cell migration was measured by Transwell migration assays and increased cell motility was measured via cell detachment assays

1.            Kong, D., Ahmad, A., Bao, B., Li, Y., Banerjee, S., and Sarkar, F. H. (2012) PloS one 7, e45045

2.            Bertino, E. M., and Otterson, G. A. (2011) Expert opinion on investigational drugs 20, 1151-1158

3.            Robey, R. W., Chakraborty, A. R., Basseville, A., Luchenko, V., Bahr, J., Zhan, Z., and Bates, S. E. (2011) Molecular pharmaceutics 8, 2021-2031

4.            Wang, Z., Li, Y., Kong, D., Banerjee, S., Ahmad, A., Azmi, A. S., Ali, S., Abbruzzese, J. L., Gallick, G. E., and Sarkar, F. H. (2009) Cancer research 69, 2400-2407

5.            Wang, Z., Li, Y., Ahmad, A., Azmi, A. S., Kong, D., Banerjee, S., and Sarkar, F. H. (2010) Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy 13, 109-118

6.            Hugo, H., Ackland, M. L., Blick, T., Lawrence, M. G., Clements, J. A., Williams, E. D., and Thompson, E. W. (2007) Journal of cellular physiology 213, 374-383

7.            Thiery, J. P. (2002) Nature reviews. Cancer 2, 442-454

8.            Kong, D., Banerjee, S., Ahmad, A., Li, Y., Wang, Z., Sethi, S., and Sarkar, F. H. (2010) PloS one 5, e12445

9.            Kong, D., Li, Y., Wang, Z., and Sarkar, F. H. (2011) Cancers 3, 716-729

10.          Bao, B., Wang, Z., Ali, S., Kong, D., Li, Y., Ahmad, A., Banerjee, S., Azmi, A. S., Miele, L., and Sarkar, F. H. (2011) Cancer letters 307, 26-36

Other research papers on Cancer and Cancer Therapeutics were published on this Scientific Web site as follows:

PIK3CA mutation in Colorectal Cancer may serve as a Predictive Molecular Biomarker for adjuvant Aspirin therapy

Nanotechnology Tackles Brain Cancer

Response to Multiple Cancer Drugs through Regulation of TGF-β Receptor Signaling: a MED12 Control

Personalized medicine-based cure for cancer might not be far away

GSK for Personalized Medicine using Cancer Drugs needs Alacris systems biology model to determine the in silico effect of the inhibitor in its “virtual clinical trial”

Lung Cancer (NSCLC), drug administration and nanotechnology

Non-small Cell Lung Cancer drugs – where does the Future lie?

Cancer Innovations from across the Web

arrayMap: Genomic Feature Mining of Cancer Entities of Copy Number Abnormalities (CNAs) Data

How mobile elements in “Junk” DNA promote cancer. Part 1: Transposon-mediated tumorigenesis.

Cancer Genomics – Leading the Way by Cancer Genomics Program at UC Santa Cruz

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

mRNA interference with cancer expression

Search Results for ‘cancer’ on this web site

Cancer Genomics – Leading the Way by Cancer Genomics Program at UC Santa Cruz

Closing the gap towards real-time, imaging-guided treatment of cancer patients.

Lipid Profile, Saturated Fats, Raman Spectrosopy, Cancer Cytology

mRNA interference with cancer expression

Pancreatic cancer genomes: Axon guidance pathway genes – aberrations revealed

Biomarker tool development for Early Diagnosis of Pancreatic Cancer: Van Andel Institute and Emory University

Is the Warburg Effect the cause or the effect of cancer: A 21st Century View?

Crucial role of Nitric Oxide in Cancer

Targeting Glucose Deprived Network Along with Targeted Cancer Therapy Can be a Possible Method of Treatment

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How Mobile Elements in “Junk” DNA Promote Cancer – Part 1: Transposon-mediated Tumorigenesis

Posted in Biological Networks, Gene Regulation and Evolution, CANCER BIOLOGY & Innovations in Cancer Therapy, Computational Biology/Systems and Bioinformatics, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Genome Biology, Health Economics and Outcomes Research, Molecular Genetics & Pharmaceutical, Personalized and Precision Medicine & Genomic Research, Uncategorized, tagged , , , , , , , , , , , , on October 31, 2012| 18 Comments »

How Mobile Elements in “Junk” DNA Promote Cancer – Part 1: Transposon-mediated Tumorigenesis

Author, Writer and Curator: Stephen J. Williams, Ph.D.

How Mobile Elements in “Junk” DNA Promote Cancer – Part 1 Transposon-mediated Tumorigenesis

Word Cloud by Daniel Menzin

SOURCE

Landscape of Somatic Retrotransposition in Human Cancers. Science (2012); Vol. 337:967-971. (1)

Sequencing of the human genome via massive programs such as the Cancer Genome Atlas Program (CGAP) and the Encyclopedia of DNA Elements (ENCODE) consortium in conjunction with considerable bioinformatics efforts led by the National Center for Biotechnology Information (NCBI) have unlocked a myriad of yet unclassified genes (for good review see (2).  The project encompasses 32 institutions worldwide which, so far, have generated 1640 data sets, initially depending on microarray platforms but now moving to the more cost effective new sequencing technology.  Initially the ENCODE project focused on three types of cells: an immature white blood cell line GM12878, leukemic line K562, and an approved human embryonic cell line H1-hESC.  The analysis was rapidly expanded to another 140 cell types.  DNA sequencing had revealed 20,687 known coding regions with hints of 50 more coding regions.  Another 11,224 DNA stretches were classified as pseudogenes.  The ENCODE project reveals that many genes encode for an RNA, not protein product, so called regulatory RNAs.

However some of the most recent and interesting results focus on the noncoding regions of the human genome, previously discarded as uninteresting or “junk” DNA .  Only 2% of the human genome contains coding regions while 98% of this noncoding part of the genome is actually found to be highly active “with about 4 million constantly communicating switches” (3).  Some of these “switches” in the noncoding portion contain small, repetitive elements which are mobile throughout the genome, and can control gene expression and/or predispose to disease such as cancer.  These mobile elements, found in almost all organisms, are classified as transposable elements (TE), inserting themselves into far-reaching regions of the genome.  Retro-transposons are capable of generating new insertions through RNA intermediates.  These transposable elements are normally kept immobile by epigenetic mechanisms(4-6) however some TEs can escape epigenetic repression and insert in areas of the genome, a process described as insertional mutagenesis as the process can lead to gene alterations seen in disease(7).  In addition, this insertional mutagenesis can lead to the transformation of cells and, as described in Post 2, act as a model system to determine drivers of oncogenesis. This insertional mutagenesis is a different mechanism of genetic alteration and rearrangement seen in cancer like recombination and fusion of gene fragments as seen with the Philadelphia chromosome and BCR/ABL fusion protein (8).  The mechanism of transposition and putative effects leading to mutagenesis are described in the following figure:

Image

Figure.  Insertional mutagenesis based on transposon-mediated mechanism.  A) Basic structure of  transposon contains gene/sequence flanked by two inverted repeats (IR) and/or direct repeats (DR).  An enzyme, the transposase (red hexagon) binds and cuts at the IR/DR and transposon is pasted at another site in DNA, containing an insertion site.  B)   Multiple transpositions may results in oncogenic events by inserting in promoters leading to altered expression of genes driving oncogenesis or inserting within coding regions and inactivating tumor suppressors or activating oncogenes.  Deep sequencing of the resultant tumor genomes ( based on nested PCR from IR/DRs) may reveal common insertion sites (CIS) and oncogenic mutations could be identified.

In a bioinformatics study Eunjung Lee et al.(1), in collaboration with the Cancer Genome Atlas Research Network, the authors had analyzed 43 high-coverage whole-genome sequencing datasets from five cancer types to determine transposable element insertion sites.  Using a novel computational method, the authors had identified 194 high-confidence somatic TE insertion sites present in cancers of epithelial origin such as colorectal, prostate and ovarian, but not in brain or blood cancers.  Sixty four of the 194 detected somatic TE insertions were located within 62 annotated genes. Genes with TE insertion in colon cancers have commonly high mutation rates and enriched genes were associated with cell adhesion functions (CDH12, ROBO2,NRXN3, FPR2, COL1A1, NEGR1, NTM and CTNNA2) or tumor suppressor functions (NELL1m ROBO2, DBC1, and PARK2).  None of the somatic events were located within coding regions, with the TE sequences being detected in untranslated regions (UTR) or intronic regions.  Previous studies had shown insertion in these regions (UTR or intronic) can disrupts gene expression (9). Interestingly, most of the genes with insertion sites were down-regulated, suggested by a recent paper showing that local changes in methylation status of transposable elements can drive retro-transposition (10,11).  Indeed, the authors found that somatic insertions are biased toward the hypomethylated regions in cancer cell DNA.  The authors also confirmed that the insertion sites were unique to cancer and were somatic insertions, not germline (germline: arising during embryonic development) in origin by analyzing 44 normal genomes (41 normal blood samples from cancer patients and three healthy individuals).

The authors conclude:

“that some TE insertions provide a selective advantage during tumorigenesis,

rather than being merely passenger events that precede clonal expansion(1).”

The authors also suggest that more bioinformatics studies, which utilize the expansive genomic and epigenetic databases, could determine functional consequences of such transposable elements in cancer.  The following Post will describe how use of transposon-mediated insertional mutagenesis is leading to discoveries of the drivers (main genetic events) leading to oncogenesis.

1.            Lee, E., Iskow, R., Yang, L., Gokcumen, O., Haseley, P., Luquette, L. J., 3rd, Lohr, J. G., Harris, C. C., Ding, L., Wilson, R. K., Wheeler, D. A., Gibbs, R. A., Kucherlapati, R., Lee, C., Kharchenko, P. V., and Park, P. J. (2012) Science 337, 967-971

2.            Pennisi, E. (2012) Science 337, 1159, 1161

3.            Park, A. (2012) Don’t Trash These Genes. “Junk DNA may lead to valuable cures. in Time, Time, Inc., New York, N.Y.

4.            Maksakova, I. A., Mager, D. L., and Reiss, D. (2008) Cellular and molecular life sciences : CMLS 65, 3329-3347

5.            Slotkin, R. K., and Martienssen, R. (2007) Nature reviews. Genetics 8, 272-285

6.            Yang, N., and Kazazian, H. H., Jr. (2006) Nature structural & molecular biology 13, 763-771

7.            Hancks, D. C., and Kazazian, H. H., Jr. (2012) Current opinion in genetics & development 22, 191-203

8.            Sattler, M., and Griffin, J. D. (2001) International journal of hematology 73, 278-291

9.            Han, J. S., Szak, S. T., and Boeke, J. D. (2004) Nature 429, 268-274

10.          Reichmann, J., Crichton, J. H., Madej, M. J., Taggart, M., Gautier, P., Garcia-Perez, J. L., Meehan, R. R., and Adams, I. R. (2012) PLoS computational biology 8, e1002486

11.          Byun, H. M., Heo, K., Mitchell, K. J., and Yang, A. S. (2012) Journal of biomedical science 19, 13

Other research paper on ENCODE and Cancer were published on this Scientific Web site as follows:

Expanding the Genetic Alphabet and linking the genome to the metabolome

Junk DNA codes for valuable miRNAs: non-coding DNA controls Diabetes

ENCODE Findings as Consortium

Reveals from ENCODE project will invite high synergistic collaborations to discover specific targets

ENCODE: the key to unlocking the secrets of complex genetic diseases

Impact of evolutionary selection on functional regions: The imprint of evolutionary selection on ENCODE regulatory elements is manifested between species and within human populations

Metabolite Identification Combining Genetic and Metabolic Information: Genetic association links unknown metabolites to functionally related genes

Advances in Separations Technology for the “OMICs” and Clarification of Therapeutic Targets

Commentary on Dr. Baker’s post “Junk DNA codes for valuable miRNAs: non-coding DNA controls Diabetes”

Cancer Genomics – Leading the Way by Cancer Genomics Program at UC Santa Cruz

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mRNA Interference with Cancer Expression

Posted in CANCER BIOLOGY & Innovations in Cancer Therapy, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Genome Biology, Molecular Genetics & Pharmaceutical, Technology Transfer: Biotech and Pharmaceutical, tagged , , , , , , , on October 26, 2012| 5 Comments »

mRNA Interference with Cancer Expression

Reporter: Larry H Bernstein, MD, FCAP

Article-7.3.2. mRNA interference with cancer expression

Genetic switch shuts down lung cancer tumors

Genetic switch shuts down lung cancer tumors in mice October 25, 2012 in Cancer Yale researchers manipulated a tiny genetic switch and halted growth of aggressive lung cancer tumors in mice and even prevented tumors from forming. Ads by Google Stage 4 Cancer Treatments – Chat w/a Cancer Info Expert About Stage 4 Cancer Treatment Options. – http://www.CancerCenter.com The activation of a single microRNA managed to neutralize the effects of two of the most notorious genes in cancer’s arsenal, suggesting it may have a role treating several forms of cancer, the researchers report in the Nov. 1 issue of the journal Cancer Research. “This is pretty much the best pre-clinical data that show microRNAs can be effective in lung cancer treatment,” said Frank Slack, professor of molecular, cellular & developmental biology, researcher for the Yale Cancer Center, and senior author of the paper. “These cancer genes are identical to ones found in many forms of human cancers and we are hopeful the microRNA will be of therapeutic benefit in human cancer.” Unlike drugs that act upon existing proteins, microRNAs are small pieces of genetic material that can shut down and turn off genes that produce the proteins. Slack and co-author Andrea Kasinski wanted to see if one of these microRNAs, miR-34, could block the actions of K-Ras and p53 genes, which promote proliferation and survival of cancer cells, respectively. Mice with these two mutant genes invariably develop tumors but were cancer-free when researchers activated miR-34. Also, tumor growth was halted in mice that were treated with miR-34 after they had developed cancer. Journal reference: Cancer Research Provided by Yale University

Read more at: http://medicalxpress.com/news/2012-10-genetic-lung-cancer-tumors-mice.html#jCp

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Early Biomarker for Pancreatic Cancer Identified

Posted in CANCER BIOLOGY & Innovations in Cancer Therapy, Cell Biology, Signaling & Cell Circuits, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Uncategorized, tagged , , , , , , on May 17, 2012| 4 Comments »

Early Biomarker for Pancreatic Cancer Identified

Reporter: Prabodh Kandala, PhD

Article 10.5. Early Biomarker for Pancreatic Cancer Identified

Researchers at the University of California, San Diego School of Medicine and Moores Cancer Center have identified a new biomarker and therapeutic target for pancreatic cancer, an often-fatal disease for which there is currently no reliable method for early detection or therapeutic intervention.

Pancreatic ductal adenocarcinoma, or PDAC, is the fourth-leading cause of cancer-related death. Newly diagnosed patients have a median survival of less than one year, and a 5-year survival rate of only 3 to 5 percent. Therefore, biomarkers that can identify early onset of PDAC and which could be viable drug targets are desperately needed.

‘”We found that a kinase called PEAK1 is turned on very early in pancreatic cancer,” said first author Jonathan Kelber, PhD, a postdoctoral researcher in the UCSD Department of Pathology and Moores Cancer Center. “This protein was clearly detected in biopsies of malignant tumors from human patients — at the gene and the protein levels — as well as in mouse models.”

PEAK1 is a type of tyrosine kinase — an enzyme, or type of protein, that speeds up chemical reactions and acts as an “on” or “off” switch in many cellular functions. The fact that PEAK1 expression is increased in human PDAC and that its catalytic activity is important for PDAC cell proliferation makes it an important candidate as a biomarker and therapeutic target for small molecule drug discovery.

In addition to showing that levels of PEAK1 are increased during PDAC progression, the scientists found that PEAK1 is necessary for the cancer to grow and metastasize.

“PEAK1 is a critical signaling hub, regulating cell migration and proliferation,” said Kelber. “We found that if you knock it out in PDAC cells, they form significantly smaller tumors in preclinical mouse models and fail to metastasize efficiently.”

The research team, led by principal investigator Richard Klemke, PhD, UCSD professor of pathology, studied a large, on-line data base of gene expression profiles to uncover the presence of PEAK1 in PDAC. These findings were corroborated at the protein level in patient biopsy samples from co-investigator Michael Bouvet, MD, and in mouse models developed by Andrew M. Lowy, MD, both of the UCSD Department of Surgery at Moores Cancer Center.

While many proteins are upregulated in cancers of the pancreas, there has been limited success in identifying candidates that, when inhibited, have potential as clinically approved therapeutics. However, the researchers found that inhibition of PEAK1-dependent signaling sensitized PDAC cells to existing chemotherapies such as Gemitabine, and immunotherapies such as Trastuzumab.

“Survival rates for patients with pancreatic cancer remain low,” said Bouvet. “Therefore, earlier detection and novel treatment strategies are very important if we are going to make any progress against pancreatic cancer. Since current therapies are often ineffective, our hope is that the findings from this research will open up a new line of investigation to bring a PEAK1 inhibitor to the clinic.”

Abstract:

Early biomarkers and effective therapeutic strategies are desperately needed to treat pancreatic ductal adenocarcinoma (PDAC), which has a dismal 5-year patient survival rate. Here, we report that the novel tyrosine kinase PEAK1 is upregulated in human malignancies, including human PDACs and pancreatic intraepithelial neoplasia (PanIN). Oncogenic KRas induced a PEAK1-dependent kinase amplification loop between Src, PEAK1, and ErbB2 to drive PDAC tumor growth and metastasis in vivo. Surprisingly, blockade of ErbB2 expression increased Src-dependent PEAK1 expression, PEAK1-dependent Src activation, and tumor growth in vivo, suggesting a mechanism for the observed resistance of patients with PDACs to therapeutic intervention. Importantly, PEAK1 inactivation sensitized PDAC cells to trastuzumab and gemcitabine therapy. Our findings, therefore, suggest that PEAK1 is a novel biomarker, critical signaling hub, and new therapeutic target in PDACs. Cancer Res; 72(10); 2554–64. ©2012 AACR.

http://cancerres.aacrjournals.org/content/72/10/2554

http://www.sciencedaily.com/releases/2012/05/120515070305.htm

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