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Posts Tagged ‘Aviva Lev-Ari’

Rewriting the Mathematics of Tumor Growth[1]; Teams Use Math Models to Sort Drivers from Passengers[2]:  Two JNCI Reviews by Mike Martin Regarding Genomics, Cancer, and Mutation

Curator: Stephen J. Williams, Ph.D.

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Recently, there has been extensive interest in the cancer research and oncology community on detecting those mutations responsible for the initiation and propagation of a neoplastic cell (driver mutations) versus those mutations that are randomly (or by selective pressures) acquired due to the genetic instability of the transformed cell.  The impact of either type of mutation has been a topic for debate, with a recent article showing that some passenger mutations may actually be responsible for tumor survival.  In addition many articles, highlighted on this site (and referenced below) in recent years have described the importance of classifying driver and passenger mutations for the purposes of more effective personalized medicine strategies directed against tumors. Two review articles by Mike Martin in the Journal of the National Cancer Institute (JCNI) shed light on the current efforts and successes to discriminate between these passenger and driver mutations and determine impact of each type of mutation to tumor growth.  However, as described in the associated article, the picture is not as clear cut as previously thought and highlights some revolutionary findings. In Rewriting the Mathematics of Tumor Growth, researchers discovered that driver mutations may confer such a small growth advantage that, multiple mutations, including the so called passenger mutations are necessary in order to sustain tumor growth. In fact, much experimental evidence has suggested at least six defined genetic events may be necessary for the in-vitro transformation of human cells.  The following table shows some of the genetic events required for in-vitro transformation in cell culture systems.

Genetic events required for transformation

 Species  Cell type  # of genes required for tumor formation*  Genes used  Reference Events required for priming
Human FibroblastsEmbryonic kidney 3 hTERTH-rasLarge T (a)Hahn(Weinberg) 2LT+hTERT
Mammary epithelialMyoblastsEmbryonic kidney 6 hTERTH-rasP53DDc-myccyclin D1CDK4 (b)Kendall(Counter) Hras required for tumorigenesis so probably 5 events needed
Fibroblasts 4 Large TSmall TH-rashTERT (c)Sun(Hornsby) 2Large T + H-ras
Fibroblasts 4 Large TSmall ThTERTRas (d)Rangarajan(Weinberg) 3hTERT, Ras and either small or largeT
Keratinocytes 4 CyclinD1dnp53EGFR

c-myc

(e)Goessel(Opitz) 3 for anchorage independence (cyclin D1, dnp53, EGFR),Cyclin D1+dnp53 for immortalization
HOSE 6 CDK4, cyclin D, hTERT plus combination of either P53DD, myrAkt, and H-ras or P53DD, H-ras, c-myc Bcl2 (f)Sasaki(Kiyono) 5
HOSE 3 hTERTSV40 earlyH-ras orK-ras (g)Liu(Bast) 2hTERT+ SV40 early
HOSE 3 Large ThTERTH-ras orc-erB-2 (h)Kusakari(Fujii) 2hTERT+large T
Rat Fibroblasts 2 Large TH-ras (i)Hirakawa Did not analyze
Fibroblasts 2 Large TH-ras (d)Rangarajan(Weinberg) Large T
Mouse MOSEIn p53-/- background 3 c-mycK-rasAkt (j)Orsulic
Pig Fibroblasts 6 p53DDhTERTCDK4H-ras c-myccyclin D1 (k)Adam(Counter) 5 need all butp53DD

Note: priming means events required to immortalize but not fully transform.  * Note that both ability to form colonies in soft agarose and subsequently tested for tumor formation in immunocompromised mice.

a.         Hahn, W. C., Counter, C. M., Lundberg, A. S., Beijersbergen, R. L., Brooks, M. W., and Weinberg, R. A. (1999) Creation of human tumour cells with defined genetic elements, Nature 400, 464-468.

b.         Kendall, S. D., Linardic, C. M., Adam, S. J., and Counter, C. M. (2005) A network of genetic events sufficient to convert normal human cells to a tumorigenic state, Cancer Res 65, 9824-9828.

c.         Sun, B., Chen, M., Hawks, C. L., Pereira-Smith, O. M., and Hornsby, P. J. (2005) The minimal set of genetic alterations required for conversion of primary human fibroblasts to cancer cells in the subrenal capsule assay, Neoplasia 7, 585-593.

d.         Rangarajan, A., Hong, S. J., Gifford, A., and Weinberg, R. A. (2004) Species- and cell type-specific requirements for cellular transformation, Cancer Cell 6, 171-183.

e.         Goessel, G., Quante, M., Hahn, W. C., Harada, H., Heeg, S., Suliman, Y., Doebele, M., von Werder, A., Fulda, C., Nakagawa, H., Rustgi, A. K., Blum, H. E., and Opitz, O. G. (2005) Creating oral squamous cancer cells: a cellular model of oral-esophageal carcinogenesis, Proc Natl Acad Sci U S A 102, 15599-15604.

f.          Sasaki, R., Narisawa-Saito, M., Yugawa, T., Fujita, M., Tashiro, H., Katabuchi, H., and Kiyono, T. (2009) Oncogenic transformation of human ovarian surface epithelial cells with defined cellular oncogenes, Carcinogenesis 30, 423-431.

g.         Liu, J., Yang, G., Thompson-Lanza, J. A., Glassman, A., Hayes, K., Patterson, A., Marquez, R. T., Auersperg, N., Yu, Y., Hahn, W. C., Mills, G. B., and Bast, R. C., Jr. (2004) A genetically defined model for human ovarian cancer, Cancer Res 64, 1655-1663.

h.         Kusakari, T., Kariya, M., Mandai, M., Tsuruta, Y., Hamid, A. A., Fukuhara, K., Nanbu, K., Takakura, K., and Fujii, S. (2003) C-erbB-2 or mutant Ha-ras induced malignant transformation of immortalized human ovarian surface epithelial cells in vitro, Br J Cancer 89, 2293-2298.

i.          Hirakawa, T., and Ruley, H. E. (1988) Rescue of cells from ras oncogene-induced growth arrest by a second, complementing, oncogene, Proc Natl Acad Sci U S A 85, 1519-1523.

j.          Orsulic, S., Li, Y., Soslow, R. A., Vitale-Cross, L. A., Gutkind, J. S., and Varmus, H. E. (2002) Induction of ovarian cancer by defined multiple genetic changes in a mouse model system, Cancer Cell 1, 53-62.

k.         Adam, S. J., Rund, L. A., Kuzmuk, K. N., Zachary, J. F., Schook, L. B., and Counter, C. M. (2007) Genetic induction of tumorigenesis in swine, Oncogene 26, 1038-1045.

However it may be argued that the aforementioned experimental examples were produced in cell lines with a more stable genome than that which is seen in most tumors and had used traditional assays of transformation, such as growth in soft agarose and tumorigenicity in immunocompromised mice, as endpoints of transformation, and not representative of the tumor growth seen in the clinical setting.

Therefore Bert Vogelstein, M.D., along with collaborators around the world developed a model they termed the “sequential driver mutation theory”, in which they describe that driver mutations multiply over time with each mutation “slightly increasing the tumor growth rate through a process that depends on three factors”:

  1. Driver mutation rate
  2. The 0.4% selective growth advantage
  3. Cell division time

This model was based on a combination of experimental data and computer simulations of gliobastoma multiforme and pancreatic adenocarcinoma.  Most tumor models follow a Gompertz kinetics, which show how tumor growth is exponential but eventually levels off over time.

This new theory shows though that a tumor cell with only one driver mutation can only grow so much, until a second driver mutation is required.  Using data for the COSMIC database (Catalog of Somatic Mutations in Cancer) together with analysis software CHASM (Cancer-specific High-throughput Annotation of Somatic Mutations) the researchers analyzed 713 mutations sequenced from 14 glioma patients and 562 mutations in nine pancreatic adenocarcinomas, revealing at least 100 tumor suppressor genes and 100 oncogenes altered.  Therefore, the authors suggested these may be possible driver mutations, or at least mutations required for the sustained growth of these tumors.  Applying this new model to data obtained from Dr. Giardiello’s publication concerning familial adenopolypsis in New England Journal of medicine in 19993 and 2000, the sequential driver mutation model predicted age distribution of FAP patients, number and size of polyps, and polyp growth rate than previous models.  This surprising number of required driver mutations for full transformation was also verified in a study led by University of Texas Southwestern Medical Center biologist Jerry Shay, Ph.D., who noted “this team’s surprise nearly 45% of all colorectal candidate oncogenes (65 mutations) drove malignant proliferation”[3].

However, some investigators do not believe the model is complex enough to account for other factors involved in oncogenesis, such as epigenetic factors like methylation and acetylation.  In addition the review also discusses host and tissue factors which may complicate the models, such as location where a tumor develops.  However, most of the investigators interviewed for this review agreed that focusing on this long-term progression of the disease may give us clues to other potential druggable targets.

Teams Use Math Models to Sort Drivers From Passengers

A related review from Mike Martin in JNCI [2] describes a statistical method, published in 2009 Cancer Informatics[4], which distinguishes chromosomal abnormalities that can drive oncogenesis from passenger abnormalities.  Chromosomal abnormalities, such as deletions, additions, and translocations are common in cancer.  For instance, the well-known Philadelphia chromosome, a translocation between chromosome 9 and 22 which results in the BCR-ABL tyrosine kinase fusion protein is the molecular basis of chronic myelogenous leukemia.

In the report, Eytan Domany, Ph.D., from Weizmann Institute and several colleagues from University of Lausanne, University of Haifa and the Broad Institute were analyzing chromosomal aberrations in a subset of medulloblastoma, which had more gain and losses in chromosomes than had been attributed to the disease.  Using a statistical method they termed a “volumetric sieve”, the investigators were able to identify driver versus passenger aberrations based on three filters:

  • Fraction of patients with the abnormality
  • Length of DNA involved in the aberrant chromosome
  • Abnormality’s copy number

Another method to sort the most “important” chromosomal aberrations from less relevant alterations is termed GISTIC[5], as the website describes is: a tool to identify genes targeted by somatic copy-number alterations (SCNAs) that drive cancer growth (at the Broad Institute website http://www.broadinstitute.org/software/cprg/?q=node/31).  The method allows for comparison across multiple tumors so noise is eliminated and improves consistency of analysis.  This method had been successfully used to determine driver aberrations is mesotheliomas, leukemias, and identify new oncogenes in adenocarcinomas of the lung and squamous cell carcinoma of the esophagus.

Main references for the two Mike Martin articles are as follows:

1.         Martin M: Rewriting the mathematics of tumor growth. Journal of the National Cancer Institute 2011, 103(21):1564-1565.

2.         Martin M: Aberrant chromosomes: teams use math models to sort drivers from passengers. Journal of the National Cancer Institute 2010, 102(6):369-371.

3.         Eskiocak U, Kim SB, Ly P, Roig AI, Biglione S, Komurov K, Cornelius C, Wright WE, White MA, Shay JW: Functional parsing of driver mutations in the colorectal cancer genome reveals numerous suppressors of anchorage-independent growth. Cancer research 2011, 71(13):4359-4365.

4.         Shay T, Lambiv WL, Reiner-Benaim A, Hegi ME, Domany E: Combining chromosomal arm status and significantly aberrant genomic locations reveals new cancer subtypes. Cancer informatics 2009, 7:91-104.

5.         Beroukhim R, Getz G, Nghiemphu L, Barretina J, Hsueh T, Linhart D, Vivanco I, Lee JC, Huang JH, Alexander S et al: Assessing the significance of chromosomal aberrations in cancer: methodology and application to glioma. Proceedings of the National Academy of Sciences of the United States of America 2007, 104(50):20007-20012.

Further posts on CANCER and GENOMICS and Sequencing published on the site include:

The Initiation and Growth of Molecular Biology and Genomics

Inaugural Genomics in Medicine – The Conference Program, 2/11-12/2013, San Francisco, CA

LEADERS in Genome Sequencing of Genetic Mutations for Therapeutic Drug Selection in Cancer Personalized Treatment: Part 2

Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine – Part 1

Breast Cancer: Genomic profiling to predict Survival: Combination of Histopathology and Gene Expression Analysis

Computational Genomics Center: New Unification of Computational Technologies at Stanford

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”

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

Comprehensive Genomic Characterization of Squamous Cell Lung Cancers

Mosaicism’ is Associated with Aging and Chronic Diseases like Cancer: detection of genetic mosaicism could be an early marker for detecting cancer.

http://onlinelibrary.wiley.com/doi/10.1111/j.1755-148X.2011.00905.x/full

http://pharmaceuticalintelligence.com/2013/02/05/winning-over-cancer-progression-new-oncology-drugs-to-suppress-driver-mutations-vs-passengers-mutations/

Additional references:

[1] Michor F, Iwasa Y, and Nowak MA (2004) Dynamics of cancer

progression. Nature Reviews Cancer 4, 197-205.

[2] Crespi B and Summers K (2005) Evolutionary biology of cancer.

Trends in Ecology and Evolution 20, 545-552.

[3] Merlo LMF, et al. (2006) Cancer as an evolutionary and ecological

process. Nature Reviews Cancer 6, 924-935.

[4] McFarland C, et al. “Accumulation of deleterious passenger mutations

in cancer,” in preparation.

[5] Birkbak NJ, et al. (2011) Paradoxical relationship between

chromosomal instability and survival outcome in cancer. Cancer

Research 71,3447-3452.

Read Full Post »

Reporter: Aviva Lev-Ari, PhD, RN

Inaugural Genomics in Medicine

Individualized Care for Improved Outcomes

February 11-12

Moscone North Convention Center • San Francisco, CA

Organized by

Cambridge Healthtech Institute

Monday, February 11

7:30 am Registration and Morning Coffee

8:25 Chairperson’s Opening Remarks

Screening for Rare and

Difficult to Diagnose Diseases

8:30 KEYNOTE PRESENTATION:

Genomically-Supported Diagnostic and

Drug Reposition Strategies out

of Academia

Hakon Hakonarson, M.D., Ph.D., Director, Center for Applied

Genomics, Children’s Hospital of Philadelphia

This talk will discuss genomic strategies applied in academia

to identify subsets of patients who, based on their genetic

make-up, are predicted to have a favorable response profile to

drugs that come from reposition opportunities.

9:00 Evolving Approaches to Mutation Detection in

Rare Diseases

Tom Scholl, Vice President, Research & Development,

Integrated Genetics, LabCorp

Emerging trends in this field that include the expansion of

content in clinical tests to include many loci and increased

clinical sensitivity by expanding numbers of mutations detected

or whole gene sequencing will be presented.

9:30 From Raw Sequencing Data to

Functional Interpretation

Daniel MacArthur, Ph.D., Group Leader, Analytic and

Translational Genetics Unit, Massachusetts General Hospital

This presentation will discuss the key lessons learned

from large-scale sequencing studies in both common and

rare diseases with a particular focus on finding mutations

underlying severe muscle diseases.

10:00 Coffee Break with Exhibit and Poster Viewing

10:30 Providing Whole Genome Sequencing in the Clinic

David Dimmock, M.D., Assistant Professor, Pediatrics,

Medical College of Wisconsin

This presentation will focus on advances in the implementation

of genome wide sequencing in clinical practice. It will address

counseling and consent issues specific to testing children.

Specifically, it will highlight the challenges of execution in the

acute care setting.

11:00 Clinical Utility of Whole Exome Sequencing

Christine M. Eng, M.D., Professor, Department of Molecular

and Human Genetics, Baylor College of Medicine

This presentation will discuss the role of whole exome

sequencing in the diagnostic evaluation of patients with

challenging phenotypes of genetic etiology. Examples of

clinical utility, directed medical care, and cost-effectiveness

of the whole exome approach to clinical diagnostics will be

presented.

11:30 A Neuronal Carnitine Deficiency Hypothesis

for Autism

Arthur L. Beaudet, M.D., Henry and Emma Meyer Professor

and Chair, Department of Molecular and Human Genetics,

Baylor College of Medicine

We have published a paper entitled “A common X-linked

inborn error of carnitine biosynthesis may be a risk factor for

nondysmorphic autism” (PMID: 22566635). We propose a

neuronal carnitine deficiency hypothesis as one risk factor

or cause for autism whereby 10-20% of autism might

be preventable.

12:00 pm Luncheon Presentation

(Sponsorship Opportunity Available) or Lunch on

Your Own

Predictive Tests for

Improved Patient Outcomes

1:25 Chairperson’s Remarks

1:30 Implementation of Personalized Healthcare into

Clinical Practice: Lessons Learned

Kathryn Teng, M.D., FACP, Director, Center for Personalized

Healthcare, Cleveland Clinic

Integrating a pharmacogenetics program into clinical practice

requires a vision for the future of healthcare and a roadmap to

reach that vision. Pioneering the road to achieving this vision

has brought challenges and has allowed for the creation of

solutions that might be applied universally.

2:00 Molecular Profiling of Tumors to Select Therapy

in Patients with Advanced Refractory Tumors

Ramesh Ramanathan, M.D., Medical Director, The Virginia

G. Piper Cancer Center Clinical Trials

This presentation will discuss molecular profiling of tumors

using IHC, CGH and whole genome/exome sequencing of

tumors to find actionable targets for therapy. Clinical trials

and case reports of patients treated by this approach will

be presented.

2:30 Sponsored Presentations (Opportunities Available)

3:00 Refreshment Break with Exhibit and

Poster Viewing

3:30 Gene Panels vs. Whole Exome Sequencing in

Cancer Molecular Testing

Madhuri Hegde, Ph.D., FACMG, Associate Professor, Senior

Director, Emory Genetics Laboratory, Department of Human

Genetics, Emory University School of Medicine

TriConference.com 5

Individualized Care for Improved Outcomes

4:00 Next Generation Sequencing and

Cancer Diagnostics

Phil Stephens, Ph.D., Vice President, Cancer Genomics,

Foundation Medicine

Foundation Medicine has developed FoundationOne™, a

CLIA-certified, comprehensive cancer genomic test that

analyzes routine clinical specimens for somatic alterations in

189 relevant cancer genes. Experience with the initial 1,000

consecutive patients will be presented.

4:30 KEYNOTE PRESENTATION:

Clinical Cancer Genotyping – Snapshot

John Iafrate, M.D., Ph.D., Assistant Professor,

Pathology, Harvard Medical School; Assistant

Pathologist, Massachusetts General Hospital

The challenges and opportunities of implementing a broad

genotyping assay in routine clinical management of cancer

patients will be discussed. Snapshot was launched over 3

years ago at the Massachusetts General Hospital, with the

goal of providing all cancer patients with a genetic fingerprint

to guide therapeutic decisions. Lessons learned will be

outlined, and a roadmap to effectively move testing forward

into the Next Gen sequencing era.

5:00 Breakout Discussions (See Web for Details)

6:00 Close of Day

Tuesday, February 12

8:00 am Morning Coffee

Data Management and Analysis

8:10 Chairperson’s Remarks

8:15 Under the Hood of the 1000 Genomes Project

Mark A. DePristo, Ph.D., Associate Director, Medical

and Population Genetics Analysis, Broad Institute of MIT

and Harvard (on behalf of The 1000 Genomes Project

Consortium)

This presentation discusses the evolution of the nextgeneration

sequencing (NGS) data underlying the public

1000 Genomes Project resource, from some of the earliest

technologies of 2009 to today’s state-of-the-art data. It

will also highlight key NGS analytic advances originating

from the Project.

8:45 Delivering Genomic Medicine: Challenges

and Opportunities

Heidi L. Rehm, Ph.D., FACMG, Assistant Professor,

Pathology, BWH and Harvard Medical School; Director,

Laboratory for Molecular Medicine, Partners Healthcare

Center for Personalized Genetic Medicine

This talk will cover the speaker’s experience in offering clinical

sequencing to patients, from disease-targeted panels to whole

genome analyses as well as supporting the interpretation

and delivery of those results to physicians. It will also cover

approaches to data sharing within the community.

9:15 From Sequence Files to

Sponsored by

Physicians Report and the Tools

Needed to Get There

Martin Seifert, Ph.D., CEO,

Genomatix Software

Providing actionable biology from NGS data in a report useful

to the practicing clinician is difficult. Ensuring the report is

accurate, reproducible, and reflects the biology of the patient

is an even larger task. We will show examples of Genomatix’

approach to these issues and how we successfully ensure a

secure, accurate, and reproducible report, bridging the gap

from sequencer to clinician.

9:30 Rapid Identification of

Sponsored by

Disease Causative Mutations

Ali Torkamani, Ph.D., Co-Founder & CSO,

Cypher Genomics

Recent successes in clinical genome sequencing have

highlighted the potential for sequencing to greatly improve

molecular diagnosis and clinical decision-making. However,

these successes have relied upon large bioinformatics teams

and in-depth literature surveys. We will demonstrate how the

Cypher Genomics software service can quickly return a small

set of well-annotated genetic variants most likely to contribute

to a patient’s disease.

10:00 Coffee Break with Exhibit and

Poster Viewing

Getting Genomic Testing to Clinic

10:30 Sequence Data on Demand: Access,

Visualization and Communication of Genome

Sequence Data between Physicians, Researchers,

and Patients

Sitharthan Kamalakaran, Ph.D., Senior Member, Research

Staff, Philips Research North America

Patients’ genome sequences are informative for clinical care

over the patient’s lifetime and not just for the diagnosis at

hand. We present a web-accessible interface for clinicians to

integrate relevant patient genome data in their routine practice

through clinically-framed queries.

11:00 Targeted Next Generation Sponsored by

Sequencing in FFPE Tumor Samples:

Distilling High Quality Information from Low

Quality Samples

Sachin Sah, Senior Scientist, Diagnostics Research

Development, Asuragen, Inc.

SuraSeq™ PCR-based enrichment procedures enable accurate

and sensitive mutation detection from nanogram inputs of

challenging FFPE tumor DNA. Case studies will be presented

that highlight the use of complementary NGS platforms and

novel bioinformatics for discovery and confirmation studies.

11:30 Transitioning New Technologies from the Bench to the Bedside: Direct Fetal Testing Using Circulating

Cell-Free DNA

Allan T. Bombard, M.D., CMO, Sequenom

This presentation will address clinical test implementation of new tests in the US, using circulating

cell-free DNA for noninvasive

prenatal testing (NIPT) of fetal aneuploidy from maternal plasma as an example.

12:00 Moving Genomic Screening to the Clinic: Next Steps

Bruce R. Korf, M.D., Ph.D., Wayne H. and Sara Crews Finley Chair in Medical Genetics; Professor and Chair,

Department of Genetics; Director, Heflin Center for Genomic Sciences, University of Alabama at Birmingham

Since the sequencing of the human genome there has been an expectation that a flood of advances would find their

way to the clinic, and, indeed, the pace of translation of genomics to clinical application is accelerating. It is likely that the future of

medical care will evolve by the convergence of two disruptive technologies – that of information science and genomics, which, in a

sense can be viewed as one and the same.

12:30 pm Close of Symposium

Featured Presentations

Genomically-Supported Diagnostic and

Drug Reposition Strategies out of Academia

Hakon Hakonarson, M.D., Ph.D., Director, Center

for Applied Genomics, Children’s Hospital of

Philadelphia

Clinical Cancer Genotyping – Snapshot

John Iafrate, M.D., Ph.D., Assistant Professor,

Pathology, Harvard Medical School; Assistant

Pathologist, Massachusetts General Hospital

Moving Genomic Screening to the Clinic:

Next Steps

Bruce R. Korf, M.D., Ph.D., Wayne H. and Sara

Crews Finley Chair in Medical Genetics;

Professor and Chair, Department of Genetics;

Director, Heflin Center for Genomic Sciences,

University of Alabama at Birmingham

Reasons to Attend

• Hear keynote presentations from Dr. Hakon

Hakonarson of CHOP and Dr. John Iafrate of MGH

• Find out how to transition genomic

screening to the clinic

• Discover evolving approaches to

mutation detection

• Explore data management and analysis solutions

• Learn the role of pharmacogenomics in

patient care

• Network with genomic thought leaders

• Par ticipate in interactive, problem-solving

breakout discussions

TriConference.com

February 11-15 • Moscone North Convention Center • San Francisco, CA

2013

Molecular Med

Tri-Con

Premier Sponsors:

2 Genomics in Medicine

Plenary Keynotes 2013 Sponsors

Wednesday, February 13 8:00 – 9:40 am

Personalized Oncology – Fulfilling the Promise for

Today’s Patients

In honor of the 20th anniversary of the Molecular Medicine Tri-conference, CHI and

Cancer Commons will present a plenary panel on Personalized Oncology. Innovations

such as NGS and The Cancer Genome Atlas have revealed that cancer comprises

hundreds of distinct molecular diseases. Early clinical successes with targeted

therapies suggest that cancer might one day be managed as a chronic disease using

an evolving cocktail of drugs. Representing all five conference channels, Diagnostics,

Therapeutics, Clinical, Informatics, and Cancer, a panel of experts will lead a highly

interactive exploration of what it will take to realize this vision in the near future.

Moderator: Marty Tenenbaum, Ph.D., Founder and Chairman, Cancer

Commons; Prominent AI Researcher; Cancer Survivor

Tony Blau, M.D., Professor, Department of Medicine/Hematology and

Adjunct Professor, Department of Genome Sciences, University of

Washington; Attending Physician, Seattle Cancer Care Alliance; Co-

Director, Institute for Stem Cell and Regenerative Medicine, University of

Washington and the Program for Stem and Progenitor Cell Biology at the

UW/FHCRC Cancer Consortium; Founder and Scientific Officer, Partners

in Personal Oncology

Sarah Greene, Executive Director, Cancer Commons

Laurence Marton, M.D., Adjunct Professor, Department of Laboratory

Medicine, University of California San Francisco; former Dean of

Medicine, University of Wisconsin

Jane Reese-Coulbourne, MS, ChE, Executive Director, Reagan-Udall

Foundation for the FDA; former Board Chair, Lung Cancer Alliance;

Cancer Survivor

Anil Sethi, CEO, Pinch Bio; HL7 Pioneer and Health Informatics

Entrepreneur

Joshua Stuart, Ph.D., Associate Professor, Department of Biomolecular

Engineering, University of California Santa Cruz

Thursday, February 14 8:00 – 9:40 am

Plenary Keynote Panel: Emerging Technologies &

Industry Perspectives

This session features a series of presentations on emerging and hot technologies in

diagnostics, drug discovery & development, informatics, and oncology. Interactive

Q&A discussion with the audience will be included.

Moderator: To be Announced

Gregory Parekh, Ph.D., CEO, Biocartis

Kevin Bobofchak, Ph.D., Pathway Studio Product Manager, Elsevier

Jeremy Bridge-Cook, Ph.D., Senior Vice President, Research &

Development, Luminex Corporation

Panelist to be Announced, Remedy Informatics

Harry Glorikian, Managing Partner, Scientia Advisors, LLC

Lynn R. Zieske, Ph.D., Vice President, Commercial Solutions, Singulex, Inc.

Sponsored by

Premier Sponsors:

Corporate Sponsors:

Molecular

Corporate Support Sponsors:

TriConference.com 3

Conference Programs:

Feb 13-15

Diagnostics Channel

Molecular Diagnostics

Personalized Diagnostics

Cancer Molecular Markers

Circulating Tumor Cells

Digital Pathology – NEW

Companion Diagnostics – NEW

Therapeutics Channel

Mastering Medicinal Chemistry

Cancer Biologics

Clinical and Translational Science

Clinical Channel

Oncology Clinical Trials

Clinical and Translational Science

Clinical Sequencing – NEW

Informatics Channel

Bioinformatics in the Genome Era

Integrated R&D Informatics and Knowledge Management

Cancer Channel

Cancer Molecular Markers

Circulating Tumor Cells

Predictive Pre-Clinical Models in Oncology – NEW

Oncology Clinical Trials

Cancer Biologics

Symposia*:

Feb 11-12

Targeting Cancer Stem Cells

Genomics in Medicine – NEW

Point-of-Care Diagnostics

Quantitative Real-Time PCR – NEW

Next Generation Pathology

Partnering Forum*:

Feb 11-12

Emerging Molecular Diagnostics

Short Courses*:

Feb 12

1:30-4:30pm

SC1 Identification & Characterization of Cancer Stem Cells

SC2 Commercialization Boot Camp: Manual for Success in

the Molecular Diagnostics Marketplace

SC3 NGS Data and the Cloud

SC4 Best Practices in Personalized and Translational

Medicine

SC5 Latest Advances in Molecular Pathology

SC6 Regulatory Approval of a Therapeutic & Companion

Diagnostic: Nuts & Bolts

SC7 PCR Part I: qPCR in Molecular Diagnostics

SC8 Data Visualization

SC9 Methods for Synthesis & Screening of Macrocyclic

Compound Libraries

5:00-8:00pm (Dinner)

SC10 PCR Part II: Digital PCR Applications and Advances

SC11 Sample Prep and Biorepositories for Cancer Research

SC12 Next-Generation Sequencing in Molecular Pathology:

Challenges and Applications

SC13 Strategies for Companion Diagnostics Development

SC14 Patient-Derived Cancer Tissue Xenograph Models

SC16 Microfluidics Technology and Market Trends

SC17 Open Cloud & Data Science

Get the best 5-day value! Our All Access

Packages is a convenient, cost-effective way

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TRI-CON 2013. Package includes access to

1 Symposium or Partnering Forum, 2 Short

Courses and 1 Conference Program.

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*Separate reg required with a la carte pricing

Co-located Event

4 Genomics in Medicine

Inaugural Genomics in Medicine

Monday, February 11

7:30 am Registration and Morning Coffee

8:25 Chairperson’s Opening Remarks

Screening for Rare and

Difficult to Diagnose Diseases

8:30 KEYNOTE PRESENTATION:

Genomically-Supported Diagnostic and

Drug Reposition Strategies out

of Academia

Hakon Hakonarson, M.D., Ph.D., Director, Center for Applied

Genomics, Children’s Hospital of Philadelphia

This talk will discuss genomic strategies applied in academia

to identify subsets of patients who, based on their genetic

make-up, are predicted to have a favorable response profile to

drugs that come from reposition opportunities.

9:00 Evolving Approaches to Mutation Detection in

Rare Diseases

Tom Scholl, Vice President, Research & Development,

Integrated Genetics, LabCorp

Emerging trends in this field that include the expansion of

content in clinical tests to include many loci and increased

clinical sensitivity by expanding numbers of mutations detected

or whole gene sequencing will be presented.

9:30 From Raw Sequencing Data to

Functional Interpretation

Daniel MacArthur, Ph.D., Group Leader, Analytic and

Translational Genetics Unit, Massachusetts General Hospital

This presentation will discuss the key lessons learned

from large-scale sequencing studies in both common and

rare diseases with a particular focus on finding mutations

underlying severe muscle diseases.

10:00 Coffee Break with Exhibit and Poster Viewing

10:30 Providing Whole Genome Sequencing in the Clinic

David Dimmock, M.D., Assistant Professor, Pediatrics,

Medical College of Wisconsin

This presentation will focus on advances in the implementation

of genome wide sequencing in clinical practice. It will address

counseling and consent issues specific to testing children.

Specifically, it will highlight the challenges of execution in the

acute care setting.

11:00 Clinical Utility of Whole Exome Sequencing

Christine M. Eng, M.D., Professor, Department of Molecular

and Human Genetics, Baylor College of Medicine

This presentation will discuss the role of whole exome

sequencing in the diagnostic evaluation of patients with

challenging phenotypes of genetic etiology. Examples of

clinical utility, directed medical care, and cost-effectiveness

of the whole exome approach to clinical diagnostics will be

presented.

11:30 A Neuronal Carnitine Deficiency Hypothesis

for Autism

Arthur L. Beaudet, M.D., Henry and Emma Meyer Professor

and Chair, Department of Molecular and Human Genetics,

Baylor College of Medicine

We have published a paper entitled “A common X-linked

inborn error of carnitine biosynthesis may be a risk factor for

nondysmorphic autism” (PMID: 22566635). We propose a

neuronal carnitine deficiency hypothesis as one risk factor

or cause for autism whereby 10-20% of autism might

be preventable.

12:00 pm Luncheon Presentation

(Sponsorship Opportunity Available) or Lunch on

Your Own

Predictive Tests for

Improved Patient Outcomes

1:25 Chairperson’s Remarks

1:30 Implementation of Personalized Healthcare into

Clinical Practice: Lessons Learned

Kathryn Teng, M.D., FACP, Director, Center for Personalized

Healthcare, Cleveland Clinic

Integrating a pharmacogenetics program into clinical practice

requires a vision for the future of healthcare and a roadmap to

reach that vision. Pioneering the road to achieving this vision

has brought challenges and has allowed for the creation of

solutions that might be applied universally.

2:00 Molecular Profiling of Tumors to Select Therapy

in Patients with Advanced Refractory Tumors

Ramesh Ramanathan, M.D., Medical Director, The Virginia

G. Piper Cancer Center Clinical Trials

This presentation will discuss molecular profiling of tumors

using IHC, CGH and whole genome/exome sequencing of

tumors to find actionable targets for therapy. Clinical trials

and case reports of patients treated by this approach will

be presented.

2:30 Sponsored Presentations (Opportunities Available)

3:00 Refreshment Break with Exhibit and

Poster Viewing

3:30 Gene Panels vs. Whole Exome Sequencing in

Cancer Molecular Testing

Madhuri Hegde, Ph.D., FACMG, Associate Professor, Senior

Director, Emory Genetics Laboratory, Department of Human

Genetics, Emory University School of Medicine

TriConference.com 5

Individualized Care for Improved Outcomes

4:00 Next Generation Sequencing and

Cancer Diagnostics

Phil Stephens, Ph.D., Vice President, Cancer Genomics,

Foundation Medicine

Foundation Medicine has developed FoundationOne™, a

CLIA-certified, comprehensive cancer genomic test that

analyzes routine clinical specimens for somatic alterations in

189 relevant cancer genes. Experience with the initial 1,000

consecutive patients will be presented.

4:30 KEYNOTE PRESENTATION:

Clinical Cancer Genotyping – Snapshot

John Iafrate, M.D., Ph.D., Assistant Professor,

Pathology, Harvard Medical School; Assistant

Pathologist, Massachusetts General Hospital

The challenges and opportunities of implementing a broad

genotyping assay in routine clinical management of cancer

patients will be discussed. Snapshot was launched over 3

years ago at the Massachusetts General Hospital, with the

goal of providing all cancer patients with a genetic fingerprint

to guide therapeutic decisions. Lessons learned will be

outlined, and a roadmap to effectively move testing forward

into the Next Gen sequencing era.

5:00 Breakout Discussions (See Web for Details)

6:00 Close of Day

Tuesday, February 12

8:00 am Morning Coffee

Data Management and Analysis

8:10 Chairperson’s Remarks

8:15 Under the Hood of the 1000 Genomes Project

Mark A. DePristo, Ph.D., Associate Director, Medical

and Population Genetics Analysis, Broad Institute of MIT

and Harvard (on behalf of The 1000 Genomes Project

Consortium)

This presentation discusses the evolution of the nextgeneration

sequencing (NGS) data underlying the public

1000 Genomes Project resource, from some of the earliest

technologies of 2009 to today’s state-of-the-art data. It

will also highlight key NGS analytic advances originating

from the Project.

8:45 Delivering Genomic Medicine: Challenges

and Opportunities

Heidi L. Rehm, Ph.D., FACMG, Assistant Professor,

Pathology, BWH and Harvard Medical School; Director,

Laboratory for Molecular Medicine, Partners Healthcare

Center for Personalized Genetic Medicine

This talk will cover the speaker’s experience in offering clinical

sequencing to patients, from disease-targeted panels to whole

genome analyses as well as supporting the interpretation

and delivery of those results to physicians. It will also cover

approaches to data sharing within the community.

9:15 From Sequence Files to

Sponsored by

Physicians Report and the Tools

Needed to Get There

Martin Seifert, Ph.D., CEO,

Genomatix Software

Providing actionable biology from NGS data in a report useful

to the practicing clinician is difficult. Ensuring the report is

accurate, reproducible, and reflects the biology of the patient

is an even larger task. We will show examples of Genomatix’

approach to these issues and how we successfully ensure a

secure, accurate, and reproducible report, bridging the gap

from sequencer to clinician.

9:30 Rapid Identification of

Sponsored by

Disease Causative Mutations

Ali Torkamani, Ph.D., Co-Founder & CSO,

Cypher Genomics

Recent successes in clinical genome sequencing have

highlighted the potential for sequencing to greatly improve

molecular diagnosis and clinical decision-making. However,

these successes have relied upon large bioinformatics teams

and in-depth literature surveys. We will demonstrate how the

Cypher Genomics software service can quickly return a small

set of well-annotated genetic variants most likely to contribute

to a patient’s disease.

10:00 Coffee Break with Exhibit and

Poster Viewing

Getting Genomic Testing to Clinic

10:30 Sequence Data on Demand: Access,

Visualization and Communication of Genome

Sequence Data between Physicians, Researchers,

and Patients

Sitharthan Kamalakaran, Ph.D., Senior Member, Research

Staff, Philips Research North America

Patients’ genome sequences are informative for clinical care

over the patient’s lifetime and not just for the diagnosis at

hand. We present a web-accessible interface for clinicians to

integrate relevant patient genome data in their routine practice

through clinically-framed queries.

11:00 Targeted Next Generation Sponsored by

Sequencing in FFPE Tumor Samples:

Distilling High Quality Information from Low

Quality Samples

Sachin Sah, Senior Scientist, Diagnostics Research

Development, Asuragen, Inc.

SuraSeq™ PCR-based enrichment procedures enable accurate

and sensitive mutation detection from nanogram inputs of

challenging FFPE tumor DNA. Case studies will be presented

that highlight the use of complementary NGS platforms and

novel bioinformatics for discovery and confirmation studies.

NEW

TriConference.com 6

Recommended Programs:

Main Conference

• Personalized Diagnostics

Short Courses

• NGS Data and the Cloud

• PCR Part I: qPCR in Molecular Diagnostics

• NGS in Molecular Pathology

• PCR Part II: Digital PCR Applications and Advances

11:30 Transitioning New Technologies from the Bench to the Bedside: Direct Fetal Testing Using Circulating

Cell-Free DNA

Allan T. Bombard, M.D., CMO, Sequenom

This presentation will address clinical test implementation of new tests in the US, using circulating cell-free DNA for noninvasive

prenatal testing (NIPT) of fetal aneuploidy from maternal plasma as an example.

12:00 Moving Genomic Screening to the Clinic: Next Steps

Bruce R. Korf, M.D., Ph.D., Wayne H. and Sara Crews Finley Chair in Medical Genetics; Professor and Chair,

Department of Genetics; Director, Heflin Center for Genomic Sciences, University of Alabama at Birmingham

Since the sequencing of the human genome there has been an expectation that a flood of advances would find their

way to the clinic, and, indeed, the pace of translation of genomics to clinical application is accelerating. It is likely that the future of

medical care will evolve by the convergence of two disruptive technologies – that of information science and genomics, which, in a

sense can be viewed as one and the same.

12:30 pm Close of Symposium

7 Genomics in Medicine

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http://www.moscone.com

Please visit TriConference.com to make your

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reserve your sleeping accommodations.You will

need to identify yourself as a Molecular Med Tri-Con

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date or after the group room block has been filled

(whichever comes first) will be accepted on a spaceand

rate-availability basis. Rooms are limited, so

please book early.

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CHI offers comprehensive sponsorship packages which include presentation

opportunities, exhibit space and branding, as well as the use of

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Opportunities may include a 15 or 30-minute podium presentation

during the main agenda. Boxed lunches are delivered into the main

session room, which guarantees audience attendance and participation.

Packages include: exhibit space, on-site branding, and more.

Invitation-Only VIP Dinner/Private Receptions

Sponsors will select their top prospects from the conference preregistration

list for an evening of networking at the hotel or at a choice

local venue. CHI will extend invitations and deliver prospects. Evening

will be customized according to sponsor’s objectives.

Exhibit

Exhibitors will enjoy facilitated networking opportunities with 3,000

highly-targeted delegates at the overall event. Speak face-to-face with

prospective clients and showcase your latest product, service, or solution.

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opportunities, including our

Valentine’s Day Soiree sponsorship!

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We offer clients numerous options for custom lead generation programs

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contact:

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reg@healthtech.com • P: 781.972.5400 or Toll-free in the U.S. 888.999.6288

Please use

keycode GDX F

when registering!

short Courses (Tuesday, Feb 12)

1 Short Course $695 $395

2 Short Courses $995 $695

Diagnostics Channel

P1 Molecular Diagnostics

P2 Personalized Diagnostics

P3 Cancer Molecular Markers

P4 Circulating Tumor Cells

P5 Digital Pathology– NEW

P6 Companion Diagnostics– NEW

Informatics Channel

P13 Bioinformatics

P14 Integrated R&D

Informatics &

Knowledge Management

Cancer Channel

P3 Cancer Molecular Markers

P4 Circulating Tumor Cells

P15 Predictive Pre-Clinical Models

in Oncology – NEW

P10 Oncology Clinical Trials

P9 Cancer Biologics

Clinical Channel

P10 Oncology Clinical Trials

P11 Clinical and

Translational Science

P12 Clinical Sequencing– NEW

Therapeutics Channel

P7 Mastering Medicinal

Chemistry Summit

P9 Cancer Biologics

P11 Clinical and

Translational Science

S1 Targeting Cancer Stem Cells S2 Genomics in Medicine S3 Point-of-Care Diagnostics S4 Quantitative Real-Time PCR S5 Next Generation Pathology

SC10 PCR Part II: Digital PCR Applications and Advances

SC11 Sample Prep and Biorepositories for Cancer Research

SC12 Next-Generation Sequencing in Molecular Pathology:

Challenges and Applications

SC13 Strategies for Companion Diagnostics Development

SC14 Patient-Derived Cancer Tissue Xenograph Models

SC16 Microfluidics Technology and Market Trends

SC17 Open Cloud & Data Science

Afternoon

SC1 Identification & Characterization of Cancer Stem Cells

SC2 Commercialization Boot Camp: Manual for Success in the Molecular Diagnostics Marketplace

SC3 NGS Data and the Cloud

SC4 Best Practices in Personalized and Translational Medicine

SC5 Latest Advances in Molecular Pathology

SC6 Regulatory Approval of a Therapeutic & Companion Diagnostic: Nuts & Bolts

SC7 PCR Part I: qPCR in Molecular Diagnostics

SC8 Data Visualization

SC9 Methods for Synthesis & Screening of Macrocyclic Compound Libraries

SOURCE:

http://www.triconference.com/uploadedFiles/MMTC/13/MMTC_Symposium_Final_GDX.pdf

Read Full Post »

Genome-Wide Detection of Single-Nucleotide and Copy-Number Variation of a Single Human Cell(1)

Reporter, Writer: Stephen J. Williams, Ph.D.

 

Most tumors exhibit a level of diversity, at the cellular, histologic, and even genetic level (2).  This genetic heterogeneity within a tumor has been a focus of recent research efforts to analyze the characteristics, expression patterns, and genetic differences between individual tumor cells.  This genetic diversity is usually manifested as single nucleotide variations (SNV) and copy number variations (CNV), both of which provide selection pressures in both cancer and evolution.

As cancer research and personalized medicine is focused on analyzing this tumor heterogeneity it has become pertinent view the tumor as a heterogeneous population of cells instead of as a homogenous mass.  In, fact, studies have suggested that cancer cell lines growing on plastic in culture, even though thought of as clonogenic, can actually display a varied degree of expression differences between neighboring cells growing on the same dish.  Indeed, cancer stem cells show an asynchronous cell division, for example a parent CD133-positive cell will divide into a CD133-positive and a CD133-negative cell(3). In addition, the discovery that circulating tumor cells (a rare population of circulating cells in the blood) can be prognostic of outcome in cancer such as inflammatory breast cancer(4), it is ever more important to develop methods to analyze single cell populations.

Harvard University researchers, Dr. Chenghang Zong, Sijia Lu, Alec Chapman and Sunney Xie developed a new amplification method utilizing multiple annealing and looping-based amplification cycles (MALBAC)(1).   A quasilinear preamplification process is used on pictograms of DNA genomic fragments (form 10 to 100 kb) isolated from a single cell.   This is performed to reduce the bias associated with nonlinear DNA amplification.  A series of random primers (which the authors termed MALBAC primers, constructed with a common sequence tags) are annealed at low temperature (0 °C). PCR rounds produce semiamplicons.  Further rounds of amplification, after a step of looping the amplicons, result in full amplicons with complementary ends.  When the two ends hybridize to form the looped DNA, this prevents use of this loop structure as a template, therefore leading to a close-to–linear amplification.    The process allows for a higher fidelity of DNA replication and the ability to amplify a whole genome.  The amplicons are then sequenced either by whole-genome sequencing methods using Sanger-sequencing to verify any single nucleotide polymorphisms.  This procedure of MALBAC-amplification resulted in coverage of 85-93% of the genome of a single cell.

As proof of principle, the authors used MALBAC to amplify the DNA of single SW480 cancer cells (picked from a clonally expanded population of a heterogeneous population (the bulk DNA).  Comparison of the MALBAC method versus the MDA method revealed copy number variations (CNV) between three individual cells, which had been picked from the clonally expanded pool. Their results were in agreement with karyotyping studies on the SW480 cell line.  Meticulous quality controls were performed to limit contamination, high false positive rates of SNV detection due to amplification bias, and false positives due to amplification or sequencing errors.

Interestingly, the authors found 35 unique single nucleotide variations which h had occurred from 20 cell divisions from a single SW480 cancer cell.  This resulted in an estimated 49 mutations which occurred in 20 generations, yielding a mutation rate of 2.5 nucleotides per generation.  In addition, the authors were able to map some of these mutations on various chromosomes and perform next-gen sequencing (deep sequencing) to verify the nucleotide mutations and found an unusually high purine-pyrimidine exchange rate.

In a subsequent paper, investigators from the same group at Harvard used this technology to sequence 99 sperm cells from a single individual to study genetic diversity created during meiotic recombination, a mechanism involved in evolution and development(5).

Reference:

1.            Zong, C., Lu, S., Chapman, A. R., and Xie, X. S. (2012) Science 338, 1622-1626

2.            Cooke, S. L., Temple, J., Macarthur, S., Zahra, M. A., Tan, L. T., Crawford, R. A., Ng, C. K., Jimenez-Linan, M., Sala, E., and Brenton, J. D. (2011) British journal of cancer 104, 361-368

3.            Guo, R., Wu, Q., Liu, F., and Wang, Y. (2011) Oncology reports 25, 141-146

4.            Giuliano, M., Giordano, A., Jackson, S., Hess, K. R., De Giorgi, U., Mego, M., Handy, B. C., Ueno, N. T., Alvarez, R. H., De Laurentiis, M., De Placido, S., Valero, V., Hortobagyi, G. N., Reuben, J. M., and Cristofanilli, M. (2011) Breast cancer research : BCR 13, R67

5.            Lu, S., Zong, C., Fan, W., Yang, M., Li, J., Chapman, A. R., Zhu, P., Hu, X., Xu, L., Yan, L., Bai, F., Qiao, J., Tang, F., Li, R., and Xie, X. S. (2012) Science 338, 1627-1630

Other related posts on this website regarding Cancer and Genomics include:

 

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

 

Identifying Aggressive Breast Cancers by Interpreting the Mathematical Patterns in the Cancer Genome

Read Full Post »

Author & Curator: Aviva Lev-Ari, PhD, RN

Article ID #16: Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine – Part 1. Published on 1/13/2013

WordCloud Image Produced by Adam Tubman

Cancer Diagnostics by Genomic Sequencing: ‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

How to Tailor Cancer Therapy to the particular Genetics of a patient’s Cancer

THIS IS A SERIES OF FOUR POINTS OF VIEW IN SUPPORT OF the Paradigm Shift in Human Genomics

‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

PRESENTED in the following FOUR PARTS. Recommended to be read in its entirety for completeness and arrival to the End Point of Present and Future Frontier of Research in Genomics

Part 1:

Research Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine

Part 2:

LEADERS in the Competitive Space of Genome Sequencing of Genetic Mutations for Therapeutic Drug Selection in Cancer Personalized Treatment

http://pharmaceuticalintelligence.com/2013/01/13/leaders-in-genome-sequencing-of-genetic-mutations-for-therapeutic-drug-selection-in-cancer-personalized-treatment-part-2/

Part 3:

Personalized Medicine: An Institute Profile – Coriell Institute for Medical Research

http://pharmaceuticalintelligence.com/2013/01/13/personalized-medicine-an-institute-profile-coriell-institute-for-medical-research-part-3/

Part 4:

The Consumer Market for Personal DNA Sequencing

http://pharmaceuticalintelligence.com/2013/01/13/consumer-market-for-personal-dna-sequencing-part-4/

 

Part 1:

Research Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine

 

In Part 1, we will address the following FIVE DIRECTIONS in Genomics Research

  • ‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities
  • Sequencing DNA from individual cells vs “humans as a whole.” Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.
  • Promising Research Directions By Watson, 1/10/2013
  • Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper
  • Molecular Analysis of the different Stages of  Cancer Progression for Targeting Therapy

First:

Predictive Biomarkers and Personalized Medicine

No to Sequencing Patient’s DNA, No to Sequencing Patient’s Tumor, Yes to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

 

MD Anderson Research

targeted agents matched with tumor molecular aberrations.

Molecular analysis

Patients whose tumors had an aberration were treated with matched targeted therapy, compared with those of consecutive patients who were not treated with matched targeted therapy

Results

40.2% – 1 or more aberration.

In 1 aberration , matched tx higher response rate  27% vs 5%

Longer time ot treatment failure  TTF 5.2 vs. 2.2

Longer survival  13.4 vs. 9 months

Pt. w/1 mutation (molecular aberrationMatched targeted therapy associated with longer TTF vs. prior systemic therapy 5.2 vs. 3.1

matched therapy was an independent factor predicting response superior to TTF

Conclusion

Not randomized study, and patients had diverse tumor types and a median of 5 prior therapies,  results suggest that identifying specific molecular abnormalities and choosing therapy based on these abnormalities is relevant in phase I clinical trials

Clin Cancer Res. 2012 Nov 15;18(22):6373-83. doi: 10.1158/1078-0432.CCR-12-1627. Epub 2012 Sep 10.

Personalized medicine in a phase I clinical trials program: the MD Anderson Cancer Center initiative.

Tsimberidou AM, Iskander NG, Hong DS, Wheler JJ, Falchook GS, Fu S, Piha-Paul S, Naing A, Janku F, Luthra R, Ye Y, Wen S, Berry D, Kurzrock R.

Source

Department of Investigational Cancer Therapeutics, Phase I Clinical Trials Program, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. atsimber@mdanderson.org

http://www.ncbi.nlm.nih.gov/pubmed?term=22966018

 

Opinion by Dr. Pierluigi Scalia, 1/11/2013.

The fact of using nanotechnology in order to target and treat abnormal cancer cells and tissues adds a powerful weapon towards eradicating the disease in the foreseeable future. However, focusing on weapons when we still have not found a reliable way to build that personalized “shooting target” (Cancer Fingerprinting) still constitutes, in my opinion, the single most relevant barrier to the adoption of Personalized treatments.

http://pharmaceuticalintelligence.com/2013/01/09/nanotechnology-personalized-medicine-and-dna-sequencing/

Ritu Saxena’s interview

http://pharmaceuticalintelligence.com/2013/01/07/personalized-medicine-gearing-up-to-tackle-cancer/

Other studies supporting this perspective

 

p53 gene deletion predicts for poor survival and non-response to therapy with purine analogs in chronic B-cell leukemias

 

Chromosome aberrations in solid tumors

 

Chromosome aberrations in B-cell chronic lymphocytic leukemia: reassessment based on molecular cytogenetic analysis

 

Multivariate analysis of prognostic factors in CLL: clinical stage, IGVH gene mutational status, and loss or mutation of the p53 gene are independent prognostic factors

 

Clonal analysis of delayed karyotypic abnormalities and gene mutations in radiation-induced genetic instability.

 

Comprehensive genetic characterization of CLL: a study on 506 cases analysed with chromosome banding analysis, interphase FISH, IgVH status and …

 

Detection of aberrations of the p53 alleles and the gene transcript in human tumor cell lines by single-strand conformation polymorphism analysis

 

Genetic aberrations detected by comparative genomic hybridization are associated with clinical outcome in renal cell carcinoma

 

VH mutation status, CD38 expression level, genomic aberrations, and survival in chronic lymphocytic leukemia

 

Microarray gene expression profiling of B-cell chronic lymphocytic leukemia subgroups defined by genomic aberrations and VH mutation status

 

… nucleophosmin (NPM1) predicts favorable prognosis in younger adults with acute myeloid leukemia and normal cytogenetics: interaction with other gene mutations

 

Transformation of follicular lymphoma to diffuse large cell lymphoma is associated with a heterogeneous set of DNA copy number and gene expression alterations

[DOC] Pax 6 Gene Research and the Pancreas

 

Molecular analysis of the cyclin-dependent kinase inhibitor gene p27/Kip1 in human malignancies

Molecular genetic analysis of oligodendroglial tumors shows preferential allelic deletions on 19q and 1p.

Cytogenetic analysis of soft tissue sarcomas: recurrent chromosome abnormalities in malignant peripheral nerve sheath tumors (MPNST)

Radiation-induced genomic instability: delayed cytogenetic aberrations and apoptosis in primary human bone marrow cells

SOURCES

Search:

Gene Mutation Aberration & Analysis of Gene Abnormalities

http://scholar.google.com/scholar?start=20&q=Gene+Mutation+Aberration+%26+Analysis+of+Gene+Abnormalities&hl=en&as_sdt=0,22&as_vis=1

Second:

Sequencing DNA from individual cells vs “humans as a whole.”

Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.

The ability to sequence single cells meant that researchers could take another approach. Working with a team at the Chinese sequencing powerhouse BGI, Auton sequenced nearly 200 sperm cells and was able to estimate the recombination rate for the man who had donated them. The work is not yet published, but Auton says that the group found an average of 24.5 recombination events per sperm cell, which is in line with estimates from indirect experiments2. Stephen Quake, a bioengineer at Stanford University in California, has performed similar experiments in 100 sperm cells and identified several places in the genome in which recombination is more likely to occur. The location of these recombination ‘hotspots’ could help population biologists to map the position of genetic variants associated with disease.

Quake also sequenced half a dozen of those 100 sperm in greater depth, and was able to determine the rate at which new mutations arise: about 30 mutations per billion bases per generation3, which is slightly higher than what others have found. “It’s basically the population biology of a sperm sample,” Quake says, and it will allow researchers to study meiosis and recombination in greater detail.

Fig1a

SOURCES:

http://www.nature.com/news/genomics-the-single-life-1.11710#/genome

Nature 491, 27–29 (01 November 2012) doi:10.1038/491027a

http://pharmaceuticalintelligence.com/2012/11/05/every-sperm-is-sacred-sequencing-dna-from-individual-cells-vs-humans-as-a-whole/

 

Third:

Promising Research Directions By Watson, 1/10/2013

The main reason drugs that target genetic glitches are not cures is that cancer cells have a work-around. If one biochemical pathway to growth and proliferation is blocked by a drug — the cancer cells activate a different, equally effective pathway.

Watson advocates a different approach: targeting features that all cancer cells, especially those in metastatic cancers, have in common.

A protein in cells called Myc. It controls more than 1,000 other molecules inside cells, including many involved in cancer. Studies suggest that turning off Myc causes cancer cells to self-destruct in a process called apoptosis.

cancer biologist Hans-Guido Wendel of Sloan-Kettering. “Blocking production of Myc is an interesting line of investigation. I think there’s promise in that.”

Personalized medicine” that targets a patient’s specific cancer-causing mutation

Watson wrote, may be “the inherently conservative nature of today’s cancer research establishments.”

http://pharmaceuticalintelligence.com/2013/01/09/the-cancer-establishments-examined-by-james-watson-co-discover-of-dna-wcrick-41953/

 

Opinion by Dr. Stephen Willliams, 1/11/2013

Kudos to both Watson and Weinstein for stating we really need to delve into tumor biology to determine functional pathways (like metabolism) which are a common feature of the malignant state ( also see my posting on differentiation therapy).

http://pharmaceuticalintelligence.com/2013/01/09/the-cancer-establishments-examined-by-james-watson-co-discover-of-dna-wcrick-41953/

http://pharmaceuticalintelligence.com/2013/01/03/differentiation-therapy-epigenetics-tackles-solid-tumors/

Fourth:

Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper

Fig2a

Figure’s SOURCE:

Figure brought to my attention by Dr. Tilda Barlyia, 1/10/2013

http://blogs.nature.com/spoonful/2012/12/metabolic-gatekeeper-provides-new-target-for-disrupting-cancer-metabolism.html

Author: Yevgeniy Grigoryev

In the 1920s, the German physiologist Otto Warburgproposed that cancer cells generate energy in ways that are distinct from normal cells. Healthy cells mainly metabolize sugar via respiration in the mitochondria, switching only to glycolysis in the cytoplasm when oxygen levels are low. In contrast, cancer cells rely on glycolysis all the time, even under oxygen-rich scenarios. This shift in how energy is produced—the so-called ‘Warburg effect’, as the observation came to be known—is now recognized as a primary driver of tumor formation, but a mechanistic explanation for the phenomenon has remained elusive.

Now, researchers have implicated a chromatin regulator known as SIRT6 as a key mediator of the switch to glycolysis in cancer cells, a finding that could lead to new therapeutic modalities. “This work is very significant for the cancer field,” says Andrei Seluanov, a cancer biologist at the University of Rochester in New York State who studies SIRT6 but was not involved in the latest study. “It establishes the role ofSIRT6 as a tumor suppressor and shows that SIRT6 loss leads to tumor formation in mice and humans.”

SIRT6 encodes one of seven mammalian proteins called sirtuins, a group of histone deacetylases that play a role in regulating metabolism, lifespan and aging. SIRT1—which is activated by resveratrol, a molecule found in the skin of red grapes—is perhaps the best known sirtuin, but several of the others are now the focus of active investigation as therapeutic targets for a range of conditions, from metabolic syndrome tocancer. Just last month, for example, a paper in Nature Medicine demonstrated that SIRT6 plays an important role in heart disease.

Six years ago, a team led by Raul Mostoslavsky, a molecular biologist at the Massachusetts General Hospital Cancer Center in Boston, first showed that SIRT6 protects mice from DNA damage and had anti-aging properties. In 2010, the same team established SIRT6 as a critical regulator of glycolysis. Now,reporting today in Cell, Mostoslavsky and his colleagues have shown that SIRT6 function is lost in cancer cells—thus, definitively establishing SIRT6 as a potent tumor suppressor.

In the latest study, the researchers showed that mouse embryonic cells genetically engineered to lackSIRT6 proliferated much faster than normal cells, growing from 5,000 cells to 200,000 cells in three days. In contrast, SIRT6-expressiong cells grew at less than half that rate over the same time period. When injected into adult mice, these SIRT6-deficient cells also rapidly formed tumors, but this tumor growth was reversed when the scientists put SIRT6 back into the cells.

“Our study provides a proof-of-concept that inhibiting glycolysis in SIRT6-deficient cells and tumors could provide a potential therapeutic approach to combat cancer,” says Mostoslavsky. “Additionally, SIRT6 may be a valuable prognostic biomarker for cancer detection.”

Currently, there are no approved anti-glycolytic drugs against cancer. However, the latest findings indicate that pharmacologically elevating SIRT6 levels might help keep tumor growth at bay. And there’s preliminary data to suggest that the work will translate from the bench to the clinic: looking at a range of cancers from human patients, Mostoslavsky’s team showed that the higher the level of SIRT6 the better the prognosis and the longer the survival times.

SOURCE:

Fifth:

Molecular Analysis of the different Stages of  Cancer Progression: The Example of Breast Cancer 

Fig2b

Figure’s SOURCE:

The molecular pathology of breast cancer progression

Alessandro Bombonati1 and Dennis C Sgroi1,2* Journal of Pathology, J Pathol 2011; 223: 307–317

(wileyonlinelibrary.com) DOI: 10.1002/path.2808

http://onlinelibrary.wiley.com/store/10.1002/path.2808/asset/2808_ftp.pdf;jsessionid=26C2C424E6948A5FAF3CBADBA385184A.d02t04v=1&t=hi26qzd4&s=a8a4aadb3fc6d448080c0ef3c67415b8277145aa

Post by Dr. Tilda Barlyia and Comments on   “The Molecular Pathology of Breast Cancer Progression”

http://pharmaceuticalintelligence.com/2013/01/10/the-molecular-pathology-of-breast-cancer-progression/

Conclusion

The Paradigm Shift in Human Genomics will follow the following FIVE DIRECTIONS:

  • No to Sequencing Patient’s DNA, No to Sequencing Patient’s Tumor, Yes to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities
  • Sequencing DNA from individual cells vs “humans as a whole.” Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.
  • Promising Research Directions By Watson, 1/10/2013
  • Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper
  • Molecular Analysis of the different Stages of  Cancer Progression for Targeting Therapy

Read Full Post »

Heroes in Medical Research: Barnett Rosenberg and the Discovery of Cisplatin (Translating Basic Research to the Clinic)

Author/Writer: Stephen J. Williams, Ph.D.

This will be a regular posting which I hope people will find interesting.  I wish to highlight the basic research which led to seminal breakthroughs in the medical field, brought on by the result of basic inquiry, thorough and detailed investigation, meticulously following the scientific method, and eventually leading to development of important medical therapies.

This month I would like to highlight the research of Dr. Barnett Rosenberg and his discovery of one of the most used and effective chemotherapeutics, cisplatin.

Cisplatin_ALX-400-040

The compound cis-PtCl2(NH3)2 (seen in the Figure ) was first described by M. Peyrone in 1845, and known for a long time as Peyrone’s salt.[3] In 1965, Barnett Rosenberg, van Camp et al. of Michigan State University  had asked a simple question and noticed that electrical fields can inhibit the division and induce filamentous growth  of Escherichia coli (E. coli) bacteria. . Although bacterial cell growth continued, cell division was arrested, the bacteria growing as filaments up to 300 times their normal length.[5]  However, Dr. Roenberg did not stop at this finding and meticulously accounting for each variable which might explain this finding, including altering the metal composistion of the electrodes.  Dr. Rosenberg thought of the possibility it was not the electric field perse, which caused the growth inhibition, but a chemical produced in the media by electrolysis.  Eventually he discovered that electrolysis of platinum electrodes generated a soluble platinum complex which inhibited binary fission in Escherichia coli (E. coli) bacteria.  In addition he isolated this platinum complex and discovered that ammonium ions were required as well, owing to the full chemical structure of cisplatin as seen above (the nitrogens moieties are bioactivated to cations). This finding led to the observation that cis PtCl2(NH3)2 was indeed highly effective at regressing the mass of sarcomas in rats.[8] Confirmation of this discovery, and extension of testing to other tumour cell lines launched the medicinal applications of cisplatin. Cisplatin was approved for use in testicular and ovarian cancers by the U.S. Food and Drug Administration on December 19, 1978.[9]

  • ^ Peyrone M. (1844). “Ueber die Einwirkung des Ammoniaks auf Platinchlorür”. Ann Chemie Pharm 51 (1): 1–29. doi:10.1002/jlac.18440510102.
  • ^ a b c Stephen Trzaska (20 June 2005). “Cisplatin”. C&EN News 83 (25).
  • ^ Rosenberg, B.; Van Camp, L.; Krigas, T. (1965). “Inhibition of cell division in Escherichia coli by electrolysis products from a platinum electrode”. Nature 205 (4972): 698–699. doi:10.1038/205698a0. PMID 14287410.

Barnett Rosenberg

From Wikipedia, the free encyclopedia

403px-Nci-vol-8173-300_barnett_rosenberg

Barnett Rosenberg

Born November 16, 1926
New York, New York
Died August 8, 2009
Lansing, Michigan
Fields Physics/Biophysics
Institutions Michigan State University
Known for Cisplatin

Barnett Rosenberg (16 November 1926 – 8 August 2009) was an American chemist best known for the discovery of the anti-cancer drug cisplatin.[1]

Rosenberg graduated from Brooklyn College in 1948 and obtained his PhD in Physics at New York University (NYU) in 1956. He joined Michigan State University in 1961 and worked there until 1997.

In 1965, Rosenberg and his colleagues proved that certain platinum-containing compounds inhibited cell division and then in 1969 showed that they cured solid tumors. The chemotherapy drug that eventually resulted from this work, cisplatin, obtained US Food and Drug Administration (FDA) approval in 1978 and went on to become a widely used anticancer drug. The initial discovery was quite serendipitous. Rosenberg was looking into the effects of an electric field on the growth of bacteria. He noticed that bacteria ceased to divide when placed in an electric field and eventually pinned down the cause of this phenomenon to the platinum electrode he was using.[2]

He was awarded the Charles F. Kettering Prize in 1984 and the Harvey Prize in 1984. [3]

  1. ^ Rosenberg, B.; Van Camp, L.; Krigas, T. (1965). “Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode”. Nature 205 (4972): 698–9. doi:10.1038/205698a0. PMID 14287410. edit
  2. ^ Petsko, G. A. (2002). “A christmas carol”. Genome biology 3 (1): COMMENT1001. PMC 150444. PMID 11806819edit
  3. ^ http://visualsonline.cancer.gov/details.cfm?imageid=8173

Other posts of interest  in this site  include:

Interview with the co-discoverer of the structure of DNA: Watson on The Double Helix and his changing view of Rosalind Franklin

Otto Warburg, A Giant of Modern Cellular Biology

Inspiration From Dr. Maureen Cronin’s Achievements in Applying Genomic Sequencing to Cancer Diagnostics

Read Full Post »

Differentiation Therapy – Epigenetics Tackles Solid Tumors

Author-Writer: Stephen J. Williams, Ph.D.

Updated 4/27/2021

Screen Shot 2021-07-19 at 7.04.21 PM

Word Cloud By Danielle Smolyar

Genetic and epigenetic events within a cell which promote a block in normal development or differentiation coupled with unregulated proliferation are hallmarks of neoplastic transformation.  Differentiation therapy is a chemotherapeutic strategy directed at re-activating endogenous cellular differentiation programs in a tumor cell therefore driving the cancerous cell to a state closer resembling the normal or preneoplastic cell and therefore incurring loss of the tumorigenic phenotype.

This post will deal with:

  • Agents such as histone deacetylase inhibitors (HDACi), retinoids, and PPARϒ agonists which have been shown to reactivate terminal differentiation programs in solid tumors
  • Clinical trials in solid tumors
  • Issues regarding the use of differentiation therapy in solid tumors

This post is a follow-up post to Histone Deacetylase Inhibitors Induce Epithelial-to-Mesenchymal Transition in Prostate Cancer Cells

To put the need for alternate chemotherapeutic strategies in perspective, one is referred to the National Cancer Statistics from http://www.cancer.gov show that 33% of cancer patients, treated with standard cytolytic chemotherapy, will still die within five years (i.e. one in three will die within 5 years).  However the addition of the differentiation agent retinoic acid to standard chemotherapy regimen for treatment of acute promyelocytic leukemia (APML) had improved 5 year survival rates from a range of 50-80% up to near 90% complete remission rates while 75% become disease free, an astonishing success story.  For a review of APML please be referred to http://en.wikipedia.org/wiki/Acute_promyelocytic_leukemia.  Briefly, APML is predominantly a result of the chromosomal translocation producing a fusion gene between the promyelocytic leukemia (PML) and RARα receptor genes.  The PML-RARα fusion protein recruits transcriptional repressors, histone deacetylases (HDACs), and DNA methyltransferases.  Treatment with pharmacologic doses of retinoic acid dissociates the PML-RARα from HDACs and results in degradation of PML-RARα, eventually resulting in the differentiation of the myeloid cells in APML.

Dr. Igor Matushansky of Columbia University believes such differentiation therapy could be useful in soft tissue sarcomas, due to the existence of a connective tissue (mesenchymal) stem cell,  in vitro methods which can differentiate these cells into mature tissues, and, from a gene clustering analysis his group had performed, correlation of expression signatures of each liposarcoma subtype throughout the adipocytic differentiation spectrum, including early differentiated to more mature differentiated cells(1).   A parallel study by Riester and colleagues had been able to classify breast tumors and liposarcomas along a phylogenetic tree showing solid tumors can be reclassified based on cell of origin via expression patterns(2).  In addition, other solid tumors, such as ovarian cancer are easily classified, based both on pathologic, histologic, and expression analysis into well and poorly differentiated tumors, correlating differentiation status with prognosis.

Compound Classes which have potential in

differentiation therapy for solid tumors

A. Histone Deacetylase Inhibitors (HDACi)

In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression.  Histone deacetylation leads to chromatin compaction and is associated with transcriptional repression of tumor suppressors, cell growth and differentiation.  Therefore, HDACi are promising anti-tumor agents as they may affect the cell cycle, inhibit proliferation, stimulate differentiation and induce apoptotic cell death (3). In a review by Kniptein and Gore, entinostat was found to be a well-tolerated HDACi that demonstrates promising therapeutic potential in both solid and hematologic malignancies(4). The path to the discovery of suberoylanilide hydroxamic acid (SAHA, vorinostat) began over three decades ago with our studies designed to understand why dimethylsulfoxide causes terminal differentiation of the virus-transformed cells, murine erythroleukemia cells. SAHA can cause growth arrest and death of a broad variety of transformed cells both in vitro and in vivo at concentrations that have little or no toxic effects on normal cells (for references see (5). In fact, treatment of MCF-7 breast carcinoma cells with SAHA resulted in morphologic changes resembling epithelial mammary differentiation(6).

HDAC inhibitors

Figure.  Structures of some HDACi used in clinical trials for cancer (see section below)

hdacwithsaha

Figure.  HDAC with SAHA

B. Retinoids

Vitamin A and retinoids play significant roles in basic physiological processes such as vision, reproduction, growth, development, hematopoiesis and immunity (7). Retinoids are the natural derivatives and synthetic analogs of vitamin A. They have been shown to prevent mammary carcinogenesis in rodents (8), to inhibit the growth of human cancer cells in vitro  (9,10) and be effective chemopreventive and chemotherapeutic agents in a variety of human epithelial and hematopoietic tumors (11-14).

Retinoids cannot be synthesized de novo by higher animals and consequently must be consumed in the diet. The two sources of retinoids are animal products that contain retinol and retinyl esters, and plant-derived carotenoids (provitamin A). b-carotene is the most potent vitamin A precursor and has been shown to be an active inhibitor of both tumor initiation and promotion (15).

A major function of retinol, relevant to cancer, is its function as an antioxidant. The antioxidant properties of vitamin A have been shown both in vitro and in vivo (16,17). Retinol deficiency causes oxidative damage to liver mitochondria in rats that can be reversed by vitamin A supplementation (18). A caveat to this is in vitro and in vivo evidence of chronic hypervitaminosis A inducing oxidative DNA damage, as well (19-21). Therefore, it is evident that maintaining the vitamin A concentration within a physiological range is critical to normal cell function because either a deficiency or an excess of vitamin A induces oxidative stress (22). Retinoic acids (RA) (all-trans, 9-cis and 13-cis) are the major biologically active retinoids and exert their effects by regulation of gene expression by binding two families of ligand-activated nuclear retinoid receptors (23). Retinoic acid receptors (RARs) and retinoid X receptors (RXRs) regulate the transcription of a large number of target genes that contain retinoic acid response elements (RAREs) in their promoters. Many of these genes are involved in cancer (13,24) and differentiation (24-26).

Several lines of evidence suggest involvement of defects in retinol signaling in cancer, from the observation that a vitamin A-deficient (VAD) diet leads to an increase in the number of spontaneous and chemically induced tumors in animals (27-29) to the observation that RA itself can induce  differentiation and inhibit the growth of many tumor cells (30-32), as well as the identification that components of the RA signaling pathway are absent in cancer cells (33). Vitamin A and its metabolites have been proposed to have a dual effect in cancer prevention, as antioxidants (16,17,19,34) and differentiating agents (35-37). as it is well accepted that retinoid signaling is integral in maintaining the differentiated state of many cell types (13,38). Additionally, current rationale for chemoprevention with retinoids is based, in part, on the hypothesis that some tumors, may arise due to loss of normal somatic differentiation during tissue repair.

C. PPARϒ Agonists

Peroxisome proliferator-activated receptor ϒ (PPARϒ) is a member of the steroid hormone receptor superfamily that responds to changes in lipid and glucose homeostasis but has increasing roles in differentiation and tumorigenesis. The first PPAR (PPARα) was discovered during the search of a molecular target for a group of agents then referred to as peroxisome proliferators, as they increased peroxisomal numbers in rodent liver tissue, apart from improving insulin sensitivity.  One of the first agents, developed in the early 80’s for treatment of hyperlipidemia and hperlipoproteinemia, was clofibrate.  All PPAR subtypes heterodimerize with the retinoid-x-receptor (RXR) and, upon binding of ATRA, activate target genes.

PPARϒ agonists have shown potential as a therapeutic in a variety of cancer types including bladder cancer (39), colon cancer(40),  breast cancer(41), prostate cancer(42).  There are numerous studies showing that PPARϒ agonists have anti-tumorigenic activity via anti-proliferative, pro-differentiation and anti-angiogenic mechanisms of action(43). For example, Papi et al. observed that agonists for the retinoid X receptor (6-OH-11-O-hydroxyphenanthrene), retinoic acid receptor (all-trans retinoic acid (RA)) and peroxisome proliferator-activated receptor (PPAR)-γ (pioglitazone (PGZ)), reduce the survival of MS generated from breast cancer tissues and MCF7 cells, but not from normal mammary gland or MCF10 cells(44) with concomitant upregulation of differentiation markers.

A great website for further information on PPAR is Dr. Jack Vanden Heuvel, Professor of Toxicology at Penn State University at http://ppar.cas.psu.edu/general_information.html.

D. Trabectedin

Trabectedin (ecteinascidin-743 (ET-743); Yondelis) is derived from the Caribbean tunicate Ecteinascidia turbinacta has antitumor activity by binding to the DNA minor groove thus disrupting binding of transcription factors and inhibiting DNA synthesis.  However, it has also been shown, in myxoid liposarcoma (MLS) cells, to cause dissociation of transcription factor TLS-CHOP from promoter sequences resulting in downregulation of target genes such as CHOP, PTX3 and FN1 and induces an adipogenic differentiation program by enhancing activation of CAAT/enhancer binding protein (C/EBP) family of genes.  In MLS, TLS-CHOP sequesters C/EBPβ resulting in block of differentiation programs while trabectedin disrupts this association freeing up C/EBPβ to act as transcriptional activator of genes related to differentiation.

Ongoing Cancer Clinical Trials with HDAC Inhibitors

The following is a listing of some clinical trials using histone deacetylase inhibitors in combination with approved chemotherapeutics in various tumors.  This data was taken from the New Medicine Oncology Knowledge Base ( at http://www.nmok.net).

hdactrial1 hdactrial2

Issues and Future of Differentiation-based Therapy

In the review by Filemon Dela Cruz and Igor Matushansky(1), the authors suggest that, like days of old of cytotoxic monotherapy, differentiation therapy would not evolve as a simplistic one-size-fits –all but mirror an extremely complicated process.  Therefore they suggest three theoretical mechanisms in which differentiation therapy may occur:

  1. Cancer directed differentiation: differentiation pathways are activated without correcting the underlying oncogenic mechanisms which produced the initial differentiation block
  2. Cancer reverted differentiation: correction of the underlying oncogenic mechanism results in restoration of endogenous differentiation pathways
  3. Cancer diverted differentiation: cancer cell is redirected to an earlier stage of differentiation

Finally the authors suggest that “the potential for reversion of the malignant cancer phenotype to a more benign, or at the very least a lower grade of biological aggressiveness, may serve as a critical clinical and biologic transition of a uniformly fatal cancer into one more amenable to management or to treatment using conventional therapeutic approaches.”

References:

1.            Cruz, F. D., and Matushansky, I. (2012) Oncotarget 3, 559-567

2.            Riester, M., Stephan-Otto Attolini, C., Downey, R. J., Singer, S., and Michor, F. (2010) PLoS computational biology 6, e1000777

3.            Seidel, C., Schnekenburger, M., Dicato, M., and Diederich, M. (2012) Genes & nutrition 7, 357-367

4.            Knipstein, J., and Gore, L. (2011) Expert opinion on investigational drugs 20, 1455-1467

5.            Marks, P. A. (2007) Oncogene 26, 1351-1356

6.            Munster, P. N., Troso-Sandoval, T., Rosen, N., Rifkind, R., Marks, P. A., and Richon, V. M. (2001) Cancer research 61, 8492-8497

7.            Napoli, J. L. (1999) Biochim Biophys Acta 1440, 139-162

8.            Moon, R., Metha, R., and Rao, K. (1994) Retinoids and cancer in experimental animals. in The Retinoids: Biology, Chemistry, and Medicine (Sporn, M., Roberts, A., and Goodman, D. eds.), 2 Ed., Raven Press, New York. pp 573-596

9.            De Luca, L. M. (1991) Faseb J 5, 2924-2933

10.          Gudas, L. J. (1992) Cell Growth Differ 3, 655-662

11.          Degos, L., and Parkinson, D. (1995) Retinoids in Oncology, Springer-Verlag, Berlin

12.          Lotan, R. (1996) Faseb J 10, 1031-1039

13.          Zhang, D., Holmes, W. F., Wu, S., Soprano, D. R., and Soprano, K. J. (2000) J Cell Physiol 185, 1-20

14.          Fontana, J. A., and Rishi, A. K. (2002) Leukemia 16, 463-472

15.          Suda, D., Schwartz, J., and Shklar, G. (1986) Carcinogenesis 7, 711-715

16.          Ciaccio, M., Valenza, M., Tesoriere, L., Bongiorno, A., Albiero, R., and Livrea, M. A. (1993) Arch Biochem Biophys 302, 103-108

17.          Palacios, A., Piergiacomi, V. A., and Catala, A. (1996) Mol Cell Biochem 154, 77-82

18.          Barber, T., Borras, E., Torres, L., Garcia, C., Cabezuelo, F., Lloret, A., Pallardo, F. V., and Vina, J. R. (2000) Free Radic Biol Med 29, 1-7

19.          Borras, E., Zaragoza, R., Morante, M., Garcia, C., Gimeno, A., Lopez-Rodas, G., Barber, T., Miralles, V. J., Vina, J. R., and Torres, L. (2003) Eur J Biochem 270, 1493-1501

20.          Omenn, G. S., Goodman, G. E., Thornquist, M. D., Balmes, J., Cullen, M. R., Glass, A., Keogh, J. P., Meyskens, F. L., Jr., Valanis, B., Williams, J. H., Jr., Barnhart, S., Cherniack, M. G., Brodkin, C. A., and Hammar, S. (1996) J Natl Cancer Inst 88, 1550-1559

21.          Murata, M., and Kawanishi, S. (2000) J Biol Chem 275, 2003-2008

22.          Schwartz, J. L. (1996) J Nutr 126, 1221S-1227S

23.          Chambon, P. (1996) Faseb J 10, 940-954

24.          Freemantle, S. J., Kerley, J. S., Olsen, S. L., Gross, R. H., and Spinella, M. J. (2002) Oncogene 21, 2880-2889

25.          Collins, S. J., Robertson, K. A., and Mueller, L. (1990) Mol Cell Biol 10, 2154-2163

26.          Grunt, T. W., Somay, C., Oeller, H., Dittrich, E., and Dittrich, C. (1992) J Cell Sci 103 ( Pt 2), 501-509

27.          Lasnitzki, I. (1955) Br J Cancer 9, 434-441

28.          Moore, T. (1965) Proc Nutr Soc 24, 129-135

29.          Saffiotti, U., Montesano, R., Sellakumar, A. R., and Borg, S. A. (1967) Cancer 20, 857-864

30.          Strickland, S., and Mahdavi, V. (1978) Cell 15, 393-403

31.          Breitman, T. R., Selonick, S. E., and Collins, S. J. (1980) Proc Natl Acad Sci U S A 77, 2936-2940

32.          Breitman, T. R., Collins, S. J., and Keene, B. R. (1981) Blood 57, 1000-1004

33.          Niles, R. M. (2000) Nutrition 16, 573-576

34.          Monagham, B., and Schmitt, F. (1932) J Biol Chem 96, 387-395

35.          Miller, W. H., Jr. (1998) Cancer 83, 1471-1482

36.          Miyauchi, J. (1999) Leuk Lymphoma 33, 267-280

37.          Reynolds, C. P. (2000) Curr Oncol Rep 2, 511-518

38.          Ortiz, M. A., Bayon, Y., Lopez-Hernandez, F. J., and Piedrafita, F. J. (2002) Drug Resist Updat 5, 162-175

39.          Mansure, J. J., Nassim, R., and Kassouf, W. (2009) Cancer biology & therapy 8, 6-15

40.          Osawa, E., Nakajima, A., Wada, K., Ishimine, S., Fujisawa, N., Kawamori, T., Matsuhashi, N., Kadowaki, T., Ochiai, M., Sekihara, H., and Nakagama, H. (2003) Gastroenterology 124, 361-367

41.          Stoll, B. A. (2002) Eur J Cancer Prev 11, 319-325

42.          Smith, M. R., and Kantoff, P. W. (2002) Investigational new drugs 20, 195-200

43.          Rumi, M. A., Ishihara, S., Kazumori, H., Kadowaki, Y., and Kinoshita, Y. (2004) Current medicinal chemistry. Anti-cancer agents 4, 465-477

44.          Papi, A., Guarnieri, T., Storci, G., Santini, D., Ceccarelli, C., Taffurelli, M., De Carolis, S., Avenia, N., Sanguinetti, A., Sidoni, A., Orlandi, M., and Bonafe, M. (2012) Cell death and differentiation 19, 1208-1219

Updated 4/27/2021

Epizyme’s EZH2 blocker boosts immuno-oncology response in prostate cancer models

Source: https://www.fiercebiotech.com/research/epizyme-s-ezh2-blocker-boosts-immuno-oncology-response-prostate-cancer-models

cancer cell surrounded by killer T cells
Inhibiting EZH2 either genetically or with a chemical inhibitor signaled the immune system to respond to PD-1 inhibition in prostate cancer. (NIH)

The protein EZH2 has long been known as a major driver of prostate cancer because of its ability to inactivate genes that would normally suppress tumor growth. Now, a team at Cedars-Sinai Cancer has shown in preclinical models of the disease that blocking EZH2 reduces resistance to immune-boosting checkpoint inhibitors—and they did it with the help of Epizyme, which won FDA approval for the first EZH2 blocker last year.

The Cedars-Sinai team inhibited EZH2 in preclinical prostate cancer models, activating interferon-stimulated genes in the immune system. The interferons then boosted the immune response and reversed resistance to drugs that inhibit the checkpoint PD-1, they reported in the journal Nature Cancer.

By inhibiting EZH2 either genetically or with a chemical inhibitor donated by Epizyme, the researchers used a technique called “viral mimicry” to “reopen” parts of the genome that are typically inactive, they explained in a statement. That signaled the immune system to respond to PD-1 inhibition.

Checkpoint inhibitors have been approved to treat several cancer types, but they’ve been largely disappointing in prostate cancer. Hence several research groups have been exploring combination strategies. They include the University of Texas MD Anderson Cancer Center, which published research in 2019 showing early evidence that combining checkpoint inhibition with anti-TGF-beta drug could be effective in prostate cancer.

More recently, bispecific antibodies have shown early promise in prostate cancer. Last September, Amgen presented data from a phase 1 study of AMG 160, a bispecific targeting PSMA and CD3 on T cells. The company said that 68.6% of patients experienced a decline in PSA, and eight out of 15 patients evaluated showed stable disease.

Regeneron is also developing a bispecific antibody for prostate cancer, targeting PSMA and CD28. The drug is being tested as a solo therapy and in combination with Regeneron’s PD-1 inhibitor Libtayo in a phase 1/2 clinical trial enrolling men with metastatic castration-resistant prostate cancer.

As for Epizyme’s EZH2 inhibitor, Tazverik, its path to market hasn’t been perfectly smooth. An advisory committee to the FDA questioned its efficacy and safety in its initial indication, metastatic or locally advanced epithelioid sarcoma. Still, the company got the go-ahead to market the drug in adult patients with the rare cancer last January. Then the FDA added follicular lymphoma to the label in June. The drug’s takeoff has been slower than expected, however, largely because the pandemic has prevented face-to-face interactions between the sales force and physicians.

The company is currently testing Tazverik in several other cancer types, including as a combination with standard-of-care treatments in castration-resistant prostate cancer.

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

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

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

Read Full Post »

Author: Aviva Lev-Ari, PhD,RN

UPDATED on 5/8/2013

Cardiosonic Begins Enrollment in the TIVUS I Renal Denervation Trial

April 24, 2013

April 24, 2013 — Cardiosonic Inc. announced the completion of the first phase of patient enrollment in its first-in-man (FIM) TIVUS I clinical study. The study is designed to collect data on the safety and performance of the TIVUS System, a high intensity, non-focused therapeutic ultrasound catheter system for remote tissue ablation for the treatment of hypertension by renal denervation (RDN).

The study enrolled the first five patients at Royal Perth Hospital (RPH), Australia and patient screening is continuing. Sharad Shetty, M.D., principal investigator at RPH, completed the procedures with a 100 percent acute success rate in accessing the vessels and delivering therapy. “The performance of renal denervation with an advanced, ultrasonic catheter has been shown to be quick, easy and seems to be associated with minimal pain. The TIVUS System by Cardiosonic has great potential to become an important technology for management of resistant hypertensive patients,” commented Shetty. Shetty will present interim results from the FIM trial at the Euro PCR conference, Paris, May 21 to 24.

The company completed extensive bench and animal studies and following these initial human results is submitting its next human clinical trial to 20 sites worldwide. Krishna Rocha-Singh, an advisor to the company and a leader in the rapidly growing field of RDN, from the Prairie Heart Institute at the St. John’s Hospital in Springfield, Ill., commented that, “The TIVUS system has great potential to improve the process and outcomes of RDN procedures. In addition the TIVUS system may expand the population of patients eligible for RDN therapy by obviating current anatomic and physiologic restrictions and contra-indications.”

Benny Dilmoney, Cardiosonic CEO, commented that, “We are enthusiastic about completing the first phase of enrollment and progressing towards completion of our FIM patients recruitment and follow-up. Cardiosonic has completed the development of our second generation multi-directional catheter and initiated submission for its study at 20 centers worldwide. We believe that this advanced catheter design will further improve RDN procedures.”

Posted on : 27 November 2012 in 

Renal Sympathetic Denervation: a Rapidly Evolving Field

Written by Dr. Sebastian Mafeld – Radiology Specialist Registrar, Freeman Hospital, Newcastle upon Tyne, UK and Dr. Gerard S Goh – Consultant Interventional Radiologist, St. George’s Healthcare NHS Trust, London, UK.

The 11/27/2012 paper HAS IGNORED THE ALREADY PUBLISHED LITERATURE IN THE FIELD – nothing of the mentioned in it is NEW or innovative — in 2012 that is intolerable !!

The Scientific Honesty is at Stack

PNAS Study: 2/3 of Retractions in Scientific Journals represents Fraud, Duplicate publication, and Plagiarism (Misconduct).

Reporter: Aviva Lev-Ari, PhD, RN

‘We Have a Problem in Science’

October 02, 2012

A recent study in the Proceedings of the National Academy of Sciences found that more than two-thirds of 2,000 retractions in the life science literature were attributable to some form of misconduct, including fraud, duplicate publication, and plagiarism.

The study, led by Arturo Casadevall of Albert Einstein College of Medicine, estimates that the percentage of scientific papers retracted because of fraud has increased more than 10-fold since 1975.

Carl Zimmer notes in The New York Times that previous studies have concluded that most retractions were attributable to “honest errors,” but the new study “challenges that comforting assumption.”

The authors compiled more than 2,000 retraction notices published before May 3, 2012, and then dug into the reasons behind each retraction. Some reasons were cited by the journals, but the authors also found that the retraction notices for some papers did not cite fraud as the reason for the retraction.

The rise in fraudulent papers “is a sign of a winner-take-all culture in which getting a paper published in a major journal can be the difference between heading a lab and facing unemployment,” Zimmer says.

According to Casadevall, the fact that “some fraction of people are starting to cheat” should not be taken lightly, even if the overall number of fraudulent papers is relatively low. “It convinces me more that we have a problem in science,” he says.

 Source:

For the ORIGINAL work on 

Renal Sympathetic Denervation: Updates on the State of Medicine

the Readers is called to go to the ORIGINAL SOURCES listed below:

Intravascular Stimulation of Autonomics: A Letter from Dr. Michael Scherlag

http://pharmaceuticalintelligence.com/2012/09/02/intravascular-stimulation-of-autonomics-a-letter-from-dr-michael-scherlag/

Imbalance of Autonomic Tone: The Promise of Intravascular Stimulation of Autonomics

http://pharmaceuticalintelligence.com/2012/09/02/imbalance-of-autonomic-tone-the-promise-of-intravascular-stimulation-of-autonomics/

Interaction of Nitric Oxide and Prostacyclin in Vascular Endothelium

http://pharmaceuticalintelligence.com/2012/09/14/interaction-of-nitric-oxide-and-prostacyclin-in-vascular-endothelium/

Absorb™ Bioresorbable Vascular Scaffold: An International Launch by Abbott Laboratories

http://pharmaceuticalintelligence.com/2012/09/29/absorb-bioresorbable-vascular-scaffold-an-international-launch-by-abbott-laboratories/

The Molecular Biology of Renal Disorders: Nitric Oxide – Part III

http://pharmaceuticalintelligence.com/2012/11/26/the-molecular-biology-of-renal-disorders/

Treatment of Refractory Hypertension via Percutaneous Renal Denervation

http://pharmaceuticalintelligence.com/2012/06/13/treatment-of-refractory-hypertension-via-percutaneous-renal-denervation/

Renal Denervation Technology of Vessix Vascular, Inc. been acquired by Boston Scientific Corporation (BSX) to pay up to $425 Million

http://pharmaceuticalintelligence.com/2012/11/08/renal-denervation-technology-of-vessix-vascular-inc-been-acquired-by-boston-scientific-corporation-bsx-to-pay-up-to-425-million/

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Coronary artery disease in symptomatic patients referred for coronary angiography: Predicted by Serum Protein Profiles

Reporter: Aviva Lev-Ari, PhD, RN
BMC Med. 2012 Dec 5;10(1):157. [Epub ahead of print]

Serum protein profiles predict coronary artery disease in symptomatic patients referred for coronary angiography.

Laframboise WADhir RKelly LAPetrosko PKrill-Burger JMSciulli CMLyons-Weiler MAChandran URLomakin AMasterson RVMarroquin OC,Mulukutla SRMcNamara DM.

ABSTRACT:

BACKGROUND: More than a million diagnostic cardiac catheterizations are performed annually in the US for evaluation of coronary artery anatomy and the presence of atherosclerosis. Nearly half of these patients have no significant coronary lesions or do not require mechanical or surgical revascularization. Consequently, the ability to rule out clinically significant coronary artery disease (CAD) using low cost, low risk tests of serum biomarkers in even a small percentage of patients with normal coronary arteries could be highly beneficial.

METHODS:

Serum from 359 symptomatic subjects referred for catheterization was interrogated for proteins involved in atherogenesis, atherosclerosis, and plaque vulnerability. Coronary angiography classified 150 patients without flow-limiting CAD who did not require percutaneous intervention (PCI) while 209 required coronary revascularization (stents, angioplasty, or coronary artery bypass graft surgery). Continuous variables were compared across the two patient groups for each analyte including calculation of false discovery rate (FDR [less than or equal to]1%) and Q value (P value for statistical significance adjusted to [less than or equal to]0.01).

RESULTS:

Significant differences were detected in circulating proteins from patients requiring revascularization including increased apolipoprotein B100 (APO-B100), C-reactive protein (CRP), fibrinogen, vascular cell adhesion molecule 1 (VCAM-1), myeloperoxidase (MPO), resistin, osteopontin, interleukin (IL)-1beta, IL-6, IL-10 and N-terminal fragment protein precursor brain natriuretic peptide (NT-pBNP) and decreased apolipoprotein A1 (APO-A1). Biomarker classification signatures comprising up to 5 analytes were identified using a tunable scoring function trained against 239 samples and validated with 120 additional samples. A total of 14 overlapping signatures classified patients without significant coronary disease (38% to 59% specificity) while maintaining 95% sensitivity for patients requiring revascularization. Osteopontin (14 times) and resistin (10 times) were most frequently represented among these diagnostic signatures. The most efficacious protein signature in validation studies comprised osteopontin (OPN), resistin, matrix metalloproteinase 7 (MMP7) and interferon gamma (IFNgamma) as a four-marker panel while the addition of either CRP or adiponectin (ACRP-30) yielded comparable results in five protein signatures.

CONCLUSIONS:

Proteins in the serum of CAD patients predominantly reflected (1) a positive acute phase, inflammatory response and (2) alterations in lipid metabolism, transport, peroxidation and accumulation. There were surprisingly few indicators of growth factor activation or extracellular matrix remodeling in the serum of CAD patients except for elevated OPN. These data suggest that many symptomatic patients without significant CAD could be identified by a targeted multiplex serum protein test without cardiac catheterization thereby eliminating exposure to ionizing radiation and decreasing the economic burden of angiographic testing for these patients.

 
 SOURCE:

Other related articles on this Open Access Online Scientific Journal:

 

Assessing Cardiovascular Disease with Biomarkers

http://pharmaceuticalintelligence.com/2012/12/25/assessing-cardiovascular-disease-with-biomarkers/#comment-6990

 

To Stent or Not? A Critical Decision

http://pharmaceuticalintelligence.com/2012/10/23/to-stent-or-not-a-critical-decision/

Obstructive coronary artery disease diagnosed by RNA levels of 23 genes – CardioDx heart disease test wins Medicare coverage

http://pharmaceuticalintelligence.com/2012/08/14/obstructive-coronary-artery-disease-diagnosed-by-rna-levels-of-23-genes-cardiodx-heart-disease-test-wins-medicare-coverage/

 

http://pharmaceuticalintelligence.com/?s=PCI

 

Read Full Post »

Identification of Biomarkers that are Related to the Actin Cytoskeleton

Curator and Writer: Larry H Bernstein, MD, FCAP

Article I Identification of Biomarkers that are Related to the Actin Cytoskeleton

This is Part I in a series of articles on Calcium and Cell motility.

The Series consists of the following articles:

Part I: Identification of Biomarkers that are Related to the Actin Cytoskeleton

Larry H Bernstein, MD, FCAP

http://pharmaceuticalintelligence.com/2012/12/10/identification-of-biomarkers-that-are-related-to-the-actin-cytoskeleton/

Part II: Role of Calcium, the Actin Skeleton, and Lipid Structures in Signaling and Cell Motility

Larry H. Bernstein, MD, FCAP, Stephen Williams, PhD and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/08/26/role-of-calcium-the-actin-skeleton-and-lipid-structures-in-signaling-and-cell-motility/

Part III: Renal Distal Tubular Ca2+ Exchange Mechanism in Health and Disease

Larry H. Bernstein, MD, FCAP, Stephen J. Williams, PhD
 and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/09/02/renal-distal-tubular-ca2-exchange-mechanism-in-health-and-disease/

Part IV: The Centrality of Ca(2+) Signaling and Cytoskeleton Involving Calmodulin Kinases and Ryanodine Receptors in Cardiac Failure, Arterial Smooth Muscle, Post-ischemic Arrhythmia, Similarities and Differences, and Pharmaceutical Targets

Larry H Bernstein, MD, FCAP, Justin Pearlman, MD, PhD, FACC and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/09/08/the-centrality-of-ca2-signaling-and-cytoskeleton-involving-calmodulin-kinases-and-ryanodine-receptors-in-cardiac-failure-arterial-smooth-muscle-post-ischemic-arrhythmia-similarities-and-differen/

Part V: Ca2+-Stimulated Exocytosis:  The Role of Calmodulin and Protein Kinase C in Ca2+ Regulation of Hormone and Neurotransmitter

Larry H Bernstein, MD, FCAP
and
Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/12/23/calmodulin-and-protein-kinase-c-drive-the-ca2-regulation-of-hormone-and-neurotransmitter-release-that-triggers-ca2-stimulated-exocytosis/

Part VI: Calcium Cycling (ATPase Pump) in Cardiac Gene Therapy: Inhalable Gene Therapy for Pulmonary Arterial Hypertension and Percutaneous Intra-coronary Artery Infusion for Heart Failure: Contributions by Roger J. Hajjar, MD

Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/08/01/calcium-molecule-in-cardiac-gene-therapy-inhalable-gene-therapy-for-pulmonary-arterial-hypertension-and-percutaneous-intra-coronary-artery-infusion-for-heart-failure-contributions-by-roger-j-hajjar/

Part VII: Cardiac Contractility & Myocardium Performance: Ventricular Arrhythmias and Non-ischemic Heart Failure – Therapeutic Implications for Cardiomyocyte Ryanopathy (Calcium Release-related Contractile Dysfunction) and Catecholamine Responses

Justin Pearlman, MD, PhD, FACC, Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/08/28/cardiac-contractility-myocardium-performance-ventricular-arrhythmias-and-non-ischemic-heart-failure-therapeutic-implications-for-cardiomyocyte-ryanopathy-calcium-release-related-contractile/

Part VIII: Disruption of Calcium Homeostasis: Cardiomyocytes and Vascular Smooth Muscle Cells: The Cardiac and Cardiovascular Calcium Signaling Mechanism

Justin Pearlman, MD, PhD, FACC, Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/09/12/disruption-of-calcium-homeostasis-cardiomyocytes-and-vascular-smooth-muscle-cells-the-cardiac-and-cardiovascular-calcium-signaling-mechanism/

Part IXCalcium-Channel Blockers, Calcium Release-related Contractile Dysfunction (Ryanopathy) and Calcium as Neurotransmitter Sensor

Justin Pearlman, MD, PhD, FACC, Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

Part X: Synaptotagmin functions as a Calcium Sensor: How Calcium Ions Regulate the fusion of vesicles with cell membranes during Neurotransmission

Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/09/10/synaptotagmin-functions-as-a-calcium-sensor-how-calcium-ions-regulate-the-fusion-of-vesicles-with-cell-membranes-during-neurotransmission/

Part XI: Sensors and Signaling in Oxidative Stress

Larry H. Bernstein, MD, FCAP

http://pharmaceuticalintelligence.com/2013/11/01/sensors-and-signaling-in-oxidative-stress/

Part XII: Atherosclerosis Independence: Genetic Polymorphisms of Ion Channels Role in the Pathogenesis of Coronary Microvascular Dysfunction and Myocardial Ischemia (Coronary Artery Disease (CAD))

Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2013/12/21/genetic-polymorphisms-of-ion-channels-have-a-role-in-the-pathogenesis-of-coronary-microvascular-dysfunction-and-ischemic-heart-disease/

In this article the Author will cover two types of biomarker on the function of actin in cytoskeleton mobility in situ.

  • First, is an application in developing the actin or other component, for a biotarget and then, to be able to follow it as

(a) a biomarker either for diagnosis, or

(b) for the potential treatment prediction of disease free survival.

  • Second, is mostly in the context of MI, for which there is an abundance of work to reference, and a substantial body of knowledge about

(a) treatment and long term effects of diet, exercise, and

(b) underlying effects of therapeutic drugs.

1.  Cell Membrane (cytoskeletal) Plasticity

Refer to … Squeezing Ovarian Cancer Cells to Predict Metastatic Potential: Cell Stiffness as Possible Biomarker

Reporter/curator: Prabodh Kandala, PhD

New Georgia Tech research shows that cell stiffness could be a valuable clue for doctors as they search for and treat cancerous cells before they’re able to spread. The findings, which are published in the journal PLoS One, found that highly metastatic ovarian cancer cells are several times softer than less metastatic ovarian cancer cells. This study used atomic force microscopy (AFM) to study the mechanical properties of various ovarian cell lines. A soft mechanical probe “tapped” healthy, malignant and metastatic ovarian cells to measure their stiffness. In order to spread, metastatic cells must push themselves into the bloodstream. As a result, they must be highly deformable and softer. This study results indicate that cell stiffness may be a useful biomarker to evaluate the relative metastatic potential of ovarian and perhaps other types of cancer cells.

Comparative gene expression analyses indicate that the reduced stiffness of highly metastatic HEY A8 cells is associated with actin cytoskeleton remodeling and microscopic examination of actin fiber structure in these cell lines is consistent with this prediction.   The results suggest either of two approaches. Atomic Force Microscopy is not normally used by pathologists in diagnostics. Electron microscopy requires space for making and cutting the embedded specimen, and a separate room for the instrument. The instrument is large and the technique was not suitable for anything other than research initially until EM gained importance in Renal Pathology. It has not otherwise been used.  This new method looks like it might be more justified over a spectrum of cases.

A.  Atomic Force Microscopy

So the first point related to microscopy is whether AFM has feasibility for routine clinical use in the pathologists’ hands. This requires:

  1. suitable size of equipment
  2.  suitable manipulation of the specimen
  3. The question of whether you are using overnight fixed specimen, or whether the material is used unfixed
  4. Nothing is said about staining of cells for identification.
  5. Then there is the question about whether this will increase the number of Pathologist Assistants used across the country, which I am not against.   This would be the end of “house” trained PAs, and gives more credence to the too few PA programs across the country. The PA programs have to be reviewed and accredited by NAACLS (I served 8 years on the Board). A PA is represented on the Board, and programs are inspected by qualified peers.   There is no academic recognition given to this for tenure and promotion in Pathology Departments, and a pathologist is selected for a medical advisory role by the ASCP, and must be a Medical Advisor to a MLS accredited Program.   The fact is that PAs do gross anatomic dictation of selected specimens, and they do autopsies under the guidance of a pathologist. This is the reality of the profession today. The pathologist has to be in attendance at a variety of quality review conferences, for surgical morbidity and mortality to obstetrics review, and the Cancer Review. Cytopathology and cytogenetics are in the pathology domain.   In the case of tumors of the throat, cervix, and accessible orifices, it seems plausible to receive a swab for preparation. However, sampling error is greater than for a biopsy. A directed needle biopsy or a MIS specimen is needed for the ovary.

B.  identification of biomarkers that are related to the actin cytoskeleton

The alternative to the first approach is the identification of biomarkers that are related to the actin cytoskeleton, perhaps in the nature of the lipid or apoprotein isoform that gives the cell membrane deformability. The method measuring by Atomic Force Microscopy is shown with the current method of cytological screening, and I call attention to cells clustered together that have a scant cytoplasm surrounding nuclei occupying 1/2 to 3/4 of the cell radius.  The cells are not anaplastic, but the clumps are suggestive of glnad forming epithelium.

English: Animation showing 3-D nature of clust...

English: Animation showing 3-D nature of cluster. Image:Serous carcinoma 2a – cytology.jpg (Photo credit: Wikipedia)

The cell membrane, also called the plasma memb...

The cell membrane, also called the plasma membrane or plasmalemma, is a semipermeable lipid bilayer common to all living cells. It contains a variety of biological molecules, primarily proteins and lipids, which are involved in a vast array of cellular processes. It also serves as the attachment point for both the intracellular cytoskeleton and, if present, the cell wall. (Photo credit: Wikipedia)

English: AFM bema detection

AFM non contact mode

AFM non contact mode (Photo credit: Wikipedia)

C.  The diagnosis of ovarian cancer can be problematic because it can have a long period of growth undetected.

On the other hand, it is easily accessible once there is reason to suspect it. They are terrible to deal with because they metastasize along the abdominal peritoneum and form a solid cake. It is a problem of location and silence until it is late. Once they do announce a presence on the abdominal wall, there is probably a serous effusion. It was not possible to rely on a single marker, but when CA125 was introduced, Dr. Marguerite Pinto, Chief of Cytology at Bridgeport Hospital-Yale New Haven Health came to the immnunochemistry lab and we worked out a method for analyzing effusions, as we had already done with carcinoembryonic antigen.       The use of CEA and CA125 was published by Pinto and Bernstein as a first that had an impact.  This was followed by a study with the Chief of Oncology, Dr. Martin Rosman, that showed that the 30 month survival of patients post treatment is predicted by the half-life of disappearance of CA125 in serum.  At the time of this writing, I am not sure of the extent of its use 20 years later. History has taught us that adoption can be slow, depending very much on dissemination from major academic medical centers.  On the other hand, concepts can also be stuck at academic medical centers because of a rigid and unprepared mindset in the professional community.  The best example of this is the story of Ignaz Semmelweis, the best student of Rokitansky in Vienna for discovering the cause and prevention of childbirth fever at a time that nursemaids had far better results at obstetrical delivery than physicians.  Contrary to this, Edward Jenner, the best student of John Hunter (anatomist, surgeon, and physician to James Hume), discovered vaccination from the observation that milkmaids did not get smallpox (cowpox was a better alternative).
Only this year a Nobel Prize in Physics was awarded to an Israeli scientist who, working in the US, was unable to convince his associates of his discovery of PSEUDOCRYSTALS. – Diagnostic efficiency of carcinoembryonic antigen and CA125 in the cytological evaluation of effusions. M M Pinto, L H Bernstein, R A Rudolph, D A Brogan, M Rosman Arch Pathol Lab Med 1992; 116(6):626-631 ICID: 825503 Article type: Review article – Immunoradiometric assay of CA 125 in effusions. Comparison with carcinoembryonic antigen. M M Pinto, L H Bernstein, D A Brogan, E Criscuolo Cancer 1987; 59(2):218-222 ICID: 825555 Article type: Review article – Carcinoembryonic antigen in effusions. A diagnostic adjunct to cytology. M M Pinto, L H Bernstein, D A Brogan, E M Criscuolo Acta Cytologica 1987; 31(2):113-118 ICID: 825557

Predictive Modeling

Ovarian Cancer a plot of the CA125 elimination half-life vs the Kullback-Liebler distance

Ca125 half-life vs Kullback Entropy                                                          HL vs Survival KM plot 

Troponin(s) T, I, C  and the contractile apparatus  (contributed by Aviva Lev-Ari, PhD, RN)

 

For 2012 – 2013 Frontier Contribution in Cardiology on Gene Therapy Solutions for Improving Myocardial Contractility, see

Lev-Ari, A. 8/1/2013 Calcium Cycling (ATPase Pump) in Cardiac Gene Therapy: Inhalable Gene Therapy for Pulmonary Arterial Hypertension and Percutaneous Intra-coronary Artery Infusion for Heart Failure: Contributions by Roger J. Hajjar, MD

http://pharmaceuticalintelligence.com/2013/08/01/calcium-molecule-in-cardiac-gene-therapy-inhalable-gene-therapy-for-pulmonary-arterial-hypertension-and-percutaneous-intra-coronary-artery-infusion-for-heart-failure-contributions-by-roger-j-hajjar/

For explanation of Conduction prior to Myocardial Contractility, see

Lev-Ari, A. 4/28/2013 Genetics of Conduction Disease: Atrioventricular (AV) Conduction Disease (block): Gene Mutations – Transcription, Excitability, and Energy Homeostasis

http://pharmaceuticalintelligence.com/2013/04/28/genetics-of-conduction-disease-atrioventricular-av-conduction-disease-block-gene-mutations-transcription-excitability-and-energy-homeostasis/

The contraction of skeletal muscle is triggered by nerve impulses, which stimulate the release of Ca2+ from the sarcoplasmic reticulum—a specialized network of internal membranes, similar to the endoplasmic reticulum, that stores high concentrations of Ca2+ ions. The release of Ca2+ from the sarcoplasmic reticulum increases the concentration of Ca2+ in the cytosol from approximately 10-7 to 10-5 M. The increased Ca2+ concentration signals muscle contraction via the action of two accessory proteins bound to the actin filaments: tropomyosin and troponin (Figure 11.25). Tropomyosin is a fibrous protein that binds lengthwise along the groove of actin filaments. In striated muscle, each tropomyosin molecule is bound to troponin, which is a complex of three polypeptides: troponin C (Ca2+-binding), troponin I (inhibitory), and troponin T (tropomyosin-binding).

  • When the concentration of Ca2+ is low, the complex of the troponins with tropomyosin blocks the interaction of actin and myosin, so the muscle does not contract.
  • At high concentrations, Ca2+ binding to troponin C shifts the position of the complex, relieving this inhibition and allowing contraction to proceed.

Figure 11.25

Association of tropomyosin and troponins with actin filaments. (A) Tropomyosin binds lengthwise along actin filaments and, in striated muscle, is associated with a complex of three troponins: troponin I (TnI), troponin C (TnC), and troponin T (TnT). In (more…)
Contractile Assemblies of Actin and Myosin in Nonmuscle Cells

Contractile assemblies of actin and myosin, resembling small-scale versions of muscle fibers, are present also in nonmuscle cells. As in muscle, the actin filaments in these contractile assemblies are interdigitated with bipolar filaments of myosin II, consisting of 15 to 20 myosin II molecules, which produce contraction by sliding the actin filaments relative to one another (Figure 11.26). The actin filaments in contractile bundles in nonmuscle cells are also associated with tropomyosin, which facilitates their interaction with myosin II, probably by competing with filamin for binding sites on actin.

Figure 11.26

Contractile assemblies in nonmuscle cells. Bipolar filaments of myosin II produce contraction by sliding actin filaments in opposite directions.

Two examples of contractile assemblies in nonmuscle cells, stress fibers and adhesion belts, were discussed earlier with respect to attachment of the actin cytoskeleton to regions of cell-substrate and cell-cell contacts (see Figures 11.13 and 11.14). The contraction of stress fibers produces tension across the cell, allowing the cell to pull on a substrate (e.g., the extracellular matrix) to which it is anchored. The contraction of adhesion belts alters the shape of epithelial cell sheets: a process that is particularly important during embryonic development, when sheets of epithelial cells fold into structures such as tubes.

The most dramatic example of actin-myosin contraction in nonmuscle cells, however, is provided by cytokinesis—the division of a cell into two following mitosis (Figure 11.27). Toward the end of mitosis in animal cells, a contractile ring consisting of actin filaments and myosin II assembles just underneath the plasma membrane. Its contraction pulls the plasma membrane progressively inward, constricting the center of the cell and pinching it in two. Interestingly, the thickness of the contractile ring remains constant as it contracts, implying that actin filaments disassemble as contraction proceeds. The ring then disperses completely following cell division.

Figure 11.27

Cytokinesis. Following completion of mitosis (nuclear division), a contractile ring consisting of actin filaments and myosin II divides the cell in two.

http://www.ncbi.nlm.nih.gov/books/NBK9961/

2.  Use of Troponin(s) in Diagnosis

Troponins T and I are released into the circulation at the time of an acute coronary syndrome (ACS).  Troponin T was first introduced by Roche (developed in Germany) for the Roche platform as a superior biomarker for identifying acute myocardial infarction (AMI), because of a monoclonal specificity to the cardiac troponin T.  It could not be measured on any other platform (limited license patent), so the Washington University Clinical Chemistry group developed a myocardiocyte specific troponin I that quickly became widely available to Beckman, and was adapted to other instruments.  This was intended to replace the CK isoenzyme MB, that is highly elevated in rhabdomyolysis associated with sepsis or with anesthesia in special cases.

The troponins I and T had a tenfold scale difference, and the Receiver Operator Curve Generated cutoff was accurate for AMI, but had significant elevation with end-stage renal disease.  The industry worked in concert to develop a high sensitivity assay for each because there were some missed AMIs just below the ROC cutoff, which could be interpreted as Plaque Rupture.  However, the concept of plaque rupture had to be reconsidered, and we are left with type1 and type 2 AMI (disregarding the case of post PCI or CABG related).   This led to the current establishment of 3 standard deviations above the lowest measureable level at 10% coefficient of variation.  This has been discussed sufficiently elsewhere.  It did introduce a problem in the use of the test as a “silver bullet” once the finer distinctions aqnd the interest in using the test for prognosis as well as diagnosis.   This is where the use of another protein associated with heart failure came into play – either the B type natriuretic peptide, or its propeptide, N-terminal pro BNP.  The prognostic value of using these markers, secreted by the HEART and acting on the kidneys (sodium reabsorption) has proved useful.  But there has not been a multivariate refinement of the use of a two biomarker approach.  In the following part D, I illustrate what can be done with an algorithmic approach to multiple markers.

Software Agent for Diagnosis of AMI

Isaac E. Mayzlin, Ph.D., David Mayzlin, Larry H. Bernstein, M.D. The so called gold standard of proof of a method is considered the Receiver-Operating Characteristic Curve, developed for detecting “enemy planes or missiles”, and adopted first by radiologists in medicine.  This matches the correct “hits” to the actual calssification and it is generally taught as a plot of sensitivity vs (1 – specifity).  But what if you had no “training” variable?  Work inspired by Eugene Rypka’s bacterial classification led to Rosser Rudolph’s application of the Entropy of Shannon and Weaver to identify meaningful information, referring to what was Kullback-Liebler distance as “effective information”.  This allowed Rudolph and Bernstein to classify using disease biomarkers obtaing the same results as the ROC curve using an apl program.  The same data set was used by Bernstein, Adan et al. previously, and was again used by Izaak Mayzlin from University of Moscow with a new wrinkle.  Dr. Mayzlin created a neural network (Maynet), and then did a traditional NN with training on the data, and also clustered the data using geometric distance clustering and trained on the clusters.  It was interesting to see that the optimum cluster separation was closely related to the number of classes and the accuracy of classification.  An earlier simpler model using the slope of the MB isoenzyme increase and percent of total CK activity was perhaps related to Burton Sobel’s work on CK-MB disappearance rate for infarct size. The main process consists of three successive steps: (1)       clustering performed on training data set, (2)       neural network’s training on clusters from previous step, and (3)       classifier’s accuracy evaluation on testing data. The classifier in this research will be the ANN, created on step 2, with output in the range [0,1], that provides binary result (1 – AMI, 0 – not AMI), using decision point 0.5. Table  1.  Effect  of  selection  of  maximum  distance  on  the  number  of  classes  formed  and  on  the accuracy of recognition by ANN

Clustering Distance Factor F(D = F * R) Number ofClasses Number of Nodes in The Hidden Layers Number of Misrecognized Patterns inThe TestingSet of 43 Percent ofMisrecognized
10.90.80.7 2414135 1,  02,  03,  01,  02,  03,  0 3,  2 3,  2 121121 1 1 2.34.62.32.34.62.3 2.3 2.3

Creatine kinase B-subunit activity in serum in cases of suspected myocardial infarction: a prediction model based on the slope of MB increase and percentage CK-MB activity. L H Bernstein, G Reynoso Clin Chem 1983; 29(3):590-592 ICID: 825549 Diagnosis of acute myocardial infarction from two measurements of creatine kinase isoenzyme MB with use of nonparametric probability estimation. L H Bernstein, I J Good, G I Holtzman, M L Deaton, J Babb.  Clin Chem 1989; 35(3):444-447 ICID: 825570 – Information induction for predicting acute myocardial infarction. R A Rudolph, L H Bernstein, J Babb. Clin Chem 1988; 34(10):2031-2038 ICID: 825568

Related articles

Related articles published on this Open Access Online Scientific Journal, include the following:

Calcium Cycling (ATPase Pump) in Cardiac Gene Therapy: Inhalable Gene Therapy for Pulmonary Arterial Hypertension and Percutaneous Intra-coronary Artery Infusion for Heart Failure: Contributions by Roger J. Hajjar, MD

Aviva Lev-Ari, PhD, RN 8/1/2013

http://pharmaceuticalintelligence.com/2013/08/01/calcium-molecule-in-cardiac-gene-therapy-inhalable-gene-therapy-for-pulmonary-arterial-hypertension-and-percutaneous-intra-coronary-artery-infusion-for-heart-failure-contributions-by-roger-j-hajjar/

High-Sensitivity Cardiac Troponin Assays- Preparing the United States for High-Sensitivity Cardiac Troponin Assays

Larry Bernstein, MD, FCAP 6/13/2013

http://pharmaceuticalintelligence.com/2013/06/13/high-sensitivity-cardiac-troponin-assays/

Dealing with the Use of the High Sensitivity Troponin (hs cTn) Assays

Larry Bernstein and Aviva Lev-Ari  5/18/2013

http://pharmaceuticalintelligence.com/2013/05/18/dealing-with-the-use-of-the-hs-ctn-assays/

Acute Chest Pain/ER Admission: Three Emerging Alternatives to Angiography and PCI – Corus CAD, hs cTn, CCTA

Aviva Lev-Ari  3/10/2013

http://pharmaceuticalintelligence.com/2013/03/10/acute-chest-painer-admission-three-emerging-alternatives-to-angiography-and-pci/

  • Redberg’s conclusions are correct for the initial screening. The issue has been whether to do further testing for low or intermediate risk patients.
  • The most intriguing finding that is not at all surprising is that the CCTA added very little in the suspect group with small or moderate risk.
  • The ultra sensitive troponin threw the ROC out the window
  • The improved assay does pick up minor elevations of troponin in the absence of MI.

Critical Care | Abstract | Cardiac ischemia in patients with septic …
Aviva Lev-Ari  6/26/2013
http://pharmaceuticalintelligence.com/2013/06/26/critical-care-abstract-cardiac-ischemia-in-patients-with-septic/

  • refer to:  Cardiac ischemia in patients with septic shock randomized to vasopressin or norepinephrine

Mehta S, Granton J,  Gordon AC, Cook DJ, et al.
Critical Care 2013, 17:R117   http://dx.doi.org/10.1186/cc12789
Troponin and CK levels, and rates of ischemic ECG changes were similar in the VP and NE groups. In multivariable analysis

  • only APACHE II was associated with 28-day mortality (OR 1.07, 95% CI 1.01-1.14, p=0.033).

Assessing Cardiovascular Disease with Biomarkers

Larry H Bernstein, MD, FCAP 12/25/2012

http://pharmaceuticalintelligence.com/2012/12/25/assessing-cardiovascular-disease-with-biomarkers/

Vascular Medicine and Biology: CLASSIFICATION OF FAST ACTING THERAPY FOR PATIENTS AT HIGH RISK FOR MACROVASCULAR EVENTS Macrovascular Disease – Therapeutic Potential of cEPCs

Aviva Lev-Ari, PhD, RN 8/24/2012

http://pharmaceuticalintelligence.com/2012/08/24/vascular-medicine-and-biology-classification-of-fast-acting-therapy-for-patients-at-high-risk-for-macrovascular-events-macrovascular-disease-therapeutic-potential-of-cepcs/

 PENDING Integration

  • ‘Ryanopathy’: causes and manifestations of RyR2 dysfunction in heart failureCardiovasc Res. 2013;98:240-247,
  • Up-regulation of sarcoplasmic reticulum Ca2+ uptake leads to cardiac hypertrophy, contractile dysfunction and early mortality in mice deficient in CASQ2Cardiovasc Res. 2013;98:297-306,
  • Myocardial Delivery of Stromal Cell-Derived Factor 1 in Patients With Ischemic Heart Disease: Safe and PromisingCirc. Res.. 2013;112:746-747,
  • Circulation Research Thematic Synopsis: Cardiovascular GeneticsCirc. Res.. 2013;112:e34-e50,
  • Gene and cytokine therapy for heart failure: molecular mechanisms in the improvement of cardiac functionAm. J. Physiol. Heart Circ. Physiol.. 2012;303:H501-H512,
  • Ryanodine Receptor Phosphorylation and Heart Failure: Phasing Out S2808 and “Criminalizing” S2814Circ. Res.. 2012;110:1398-1402,

http://circres.ahajournals.org/content/110/5/777.figures-only

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Telling NO to Cardiac Risk

DDAH Says NO to ADMA(1); The DDAH/ADMA/NOS Pathway(2)

Author-Writer-Reporter:  Stephen J. Williams, PhD

Endothelium-derived nitric oxide (NO) has been shown to be vasoprotective.  Nitric oxide enhances endothelial cell survival, inhibits excessive proliferation of vascular smooth muscle cells, regulates vascular smooth muscle tone, and prevents platelets from sticking to the endothelial wall.  Together with evidence from preclinical and human studies, it is clear that impairment of the NOS pathway increases risk of cardiovascular disease (3-5).

This post contains two articles on the physiological regulation of nitric oxide (NO) by an endogenous NO synthase inhibitor asymmetrical dimethylarginine (ADMA) and ADMA metabolism by the enzyme DDAH(1,2).  Previous posts on nitric oxide, referenced at the bottom of the page, provides excellent background and further insight for this posting. In summary plasma ADMA levels are elevated in patients with cardiovascular disease and several large studies have shown that plasma ADMA is an independent biomarker for cardiovascular-related morbidity and mortality(6-8).

admacardiacrisk

admaeffects

Figure 1 A. Cardiac risks of ADMA B. Effects of ADMA (Photo credit: Wikipedia)

ADMA Production and Metabolism

Nuclear proteins such as histones can be methylated on arginine residues by protein-arginine methyltransferases, enzymes which use S-adenosylmethionine as methyl groups.  This methylation event is thought to regulate protein function, much in the way of protein acetylation and phosphorylation (9).  And much like phosphorylation, these modifications are reversible through methylesterases.   The proteolysis of these arginine-methyl modifications lead to the liberation of free guanidine-methylated arginine residues such as L-NMMA, asymmetric dimethylarginine (ADMA) and symmetrical methylarginine (SDMA).

The first two, L-NMMA and ADMA, have been shown to inhibit the activity of the endothelial NOS.  This protein turnover is substantial: for instance the authors note that each day 40% of constitutive protein in adult liver is newly synthesized protein. And in several diseases, such as muscular dystrophy, ischemic heart disease, and diabetes, it has been known since the 1970’s that protein catabolism rates are very high, with corresponding increased urinary excretion of ADMA(10-13).  Methylarginines are excreted in the urine by cationic transport.  However, the majority of ADMA and L-NMMA are degraded within the cell by dimethylaminohydrolase (DDAH), first cloned and purified in rat(14).

endogenous NO inhibitors from pubchem

Figure 2.  Endogenous inhibitors of NO synthase.  Chemical structures generated from PubChem.

DDAH

DDAH specifically hydrolyzes ADMA and L-NMMA to yield citruline and demethylamine and usually shows co-localization with NOS. Pharmacologic inhibition of DDAH activity causes accumulation of ADMA and can reverse the NO-mediated bradykinin-induced relaxation of human saphenous vein.

Two isoforms have been found in human:

  • DDAH1 (found in brain and kidney and associated with nNOS) and
  • DDAH2 (highly expressed in heart, placenta, and kidney and associated with eNOS).

DDAH2 can be upregulated by all-trans retinoic acid (atRA can increase NO production).  Increased reactive oxygen species and possibly homocysteine, a risk factor for cardiovascular disease, can decrease DDAH activity(15,16).

  • The importance of DDAH activity can also be seen in transgenic mice which overexpress DDAH, exhibiting increased NO production, increased insulin sensitivity, and reduced vascular resistance  (17).  Likewise,
  • Transgenic mice, null for the DDAH1, showed increase in blood pressure, decreased NO production, and significant increase in tissue and plasma ADMA and L-NMMA.

amdanosfigure

Figure 3.  The DDAH/ADMA/NOS cycle. Figure adapted from Cooke and Ghebremarian (1).

As mentioned in the article by Cooke and Ghebremariam, the authors state: the weight of the evidence indicates that DDAH is a worthy therapeutic target. Agents that increase DDAH expression are known, and 1 of these, a farnesoid X receptor agonist, is in clinical trials

http://www.interceptpharma.com

An alternate approach is to

  • develop an allosteric activator of the enzyme.  Although
  • development of an allosteric activator is not a typical pharmaceutical approach, recent studies indicate that this may be achievable aim(18).

References:

1.            Cooke, J. P., and Ghebremariam, Y. T. : DDAH says NO to ADMA.(2011) Arteriosclerosis, thrombosis, and vascular biology 31, 1462-1464

2.            Tran, C. T., Leiper, J. M., and Vallance, P. : The DDAH/ADMA/NOS pathway.(2003) Atherosclerosis. Supplements 4, 33-40

3.            Niebauer, J., Maxwell, A. J., Lin, P. S., Wang, D., Tsao, P. S., and Cooke, J. P.: NOS inhibition accelerates atherogenesis: reversal by exercise. (2003) American journal of physiology. Heart and circulatory physiology 285, H535-540

4.            Miyazaki, H., Matsuoka, H., Cooke, J. P., Usui, M., Ueda, S., Okuda, S., and Imaizumi, T. : Endogenous nitric oxide synthase inhibitor: a novel marker of atherosclerosis.(1999) Circulation 99, 1141-1146

5.            Wilson, A. M., Shin, D. S., Weatherby, C., Harada, R. K., Ng, M. K., Nair, N., Kielstein, J., and Cooke, J. P. (2010): Asymmetric dimethylarginine correlates with measures of disease severity, major adverse cardiovascular events and all-cause mortality in patients with peripheral arterial disease. Vasc Med 15, 267-274

6.            Kielstein, J. T., Impraim, B., Simmel, S., Bode-Boger, S. M., Tsikas, D., Frolich, J. C., Hoeper, M. M., Haller, H., and Fliser, D. : Cardiovascular effects of systemic nitric oxide synthase inhibition with asymmetrical dimethylarginine in humans.(2004) Circulation 109, 172-177

7.            Kielstein, J. T., Donnerstag, F., Gasper, S., Menne, J., Kielstein, A., Martens-Lobenhoffer, J., Scalera, F., Cooke, J. P., Fliser, D., and Bode-Boger, S. M. : ADMA increases arterial stiffness and decreases cerebral blood flow in humans.(2006) Stroke; a journal of cerebral circulation 37, 2024-2029

8.            Mittermayer, F., Krzyzanowska, K., Exner, M., Mlekusch, W., Amighi, J., Sabeti, S., Minar, E., Muller, M., Wolzt, M., and Schillinger, M. : Asymmetric dimethylarginine predicts major adverse cardiovascular events in patients with advanced peripheral artery disease.(2006) Arteriosclerosis, thrombosis, and vascular biology 26, 2536-2540

9.            Kakimoto, Y., and Akazawa, S.: Isolation and identification of N-G,N-G- and N-G,N’-G-dimethyl-arginine, N-epsilon-mono-, di-, and trimethyllysine, and glucosylgalactosyl- and galactosyl-delta-hydroxylysine from human urine. (1970) The Journal of biological chemistry 245, 5751-5758

10.          Inoue, R., Miyake, M., Kanazawa, A., Sato, M., and Kakimoto, Y.: Decrease of 3-methylhistidine and increase of NG,NG-dimethylarginine in the urine of patients with muscular dystrophy. (1979) Metabolism: clinical and experimental 28, 801-804

11.          Millward, D. J.: Protein turnover in skeletal muscle. II. The effect of starvation and a protein-free diet on the synthesis and catabolism of skeletal muscle proteins in comparison to liver. (1970) Clinical science 39, 591-603

12.          Goldberg, A. L., and St John, A. C.: Intracellular protein degradation in mammalian and bacterial cells: Part 2. (1976) Annual review of biochemistry 45, 747-803

13.          Dice, J. F., and Walker, C. D.: Protein degradation in metabolic and nutritional disorders. (1979) Ciba Foundation symposium, 331-350

14.          Ogawa, T., Kimoto, M., and Sasaoka, K.: Purification and properties of a new enzyme, NG,NG-dimethylarginine dimethylaminohydrolase, from rat kidney. (1989) The Journal of biological chemistry 264, 10205-10209

15.          Ito, A., Tsao, P. S., Adimoolam, S., Kimoto, M., Ogawa, T., and Cooke, J. P.: Novel mechanism for endothelial dysfunction: dysregulation of dimethylarginine dimethylaminohydrolase. (1999) Circulation 99, 3092-3095

16.          Stuhlinger, M. C., Tsao, P. S., Her, J. H., Kimoto, M., Balint, R. F., and Cooke, J. P. : Homocysteine impairs the nitric oxide synthase pathway: role of asymmetric dimethylarginine.(2001) Circulation 104, 2569-2575

17.          Sydow, K., Mondon, C. E., Schrader, J., Konishi, H., and Cooke, J. P.: Dimethylarginine dimethylaminohydrolase overexpression enhances insulin sensitivity. (2008) Arteriosclerosis, thrombosis, and vascular biology 28, 692-697

18.          Zorn, J. A., and Wells, J. A.: Turning enzymes ON with small molecules. (2010) Nature chemical biology 6, 179-188

Other research papers on Nitric Oxide and Cardiac Risk  were published on this Scientific Web site as follows:

The Nitric Oxide and Renal is presented in FOUR parts:

Part I: The Amazing Structure and Adaptive Functioning of the Kidneys: Nitric Oxide

Part II: Nitric Oxide and iNOS have Key Roles in Kidney Diseases

Part III: The Molecular Biology of Renal Disorders: Nitric Oxide

Part IV: New Insights on Nitric Oxide donors

Cardiac Arrhythmias: A Risk for Extreme Performance Athletes

What is the role of plasma viscosity in hemostasis and vascular disease risk?

Cardiovascular Risk Inflammatory Marker: Risk Assessment for Coronary Heart Disease and Ischemic Stroke – Atherosclerosis.

Endothelial Dysfunction, Diminished Availability of cEPCs, Increasing CVD Risk for Macrovascular Disease – Therapeutic Potential of cEPCs

Biochemistry of the Coagulation Cascade and Platelet Aggregation – Part I

Nitric Oxide Function in Coagulation

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