Author Interviews, Biomarkers, Cancer Research, Prostate Cancer / 28.06.2016
Targeted Proteomics Furthers Goal of Liquid Biopsy To Predict Aggressiveness of Prostate Cancer
MedicalResearch.com Interview with:
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Dr. Thomas Kislinger[/caption]
Thomas Kislinger, PhD
Senior Scientist at the Princess Margaret Cancer Centre
University Health Network
Associate Professor
Department of Medical Biophysics
University of Toronto
MedicalResearch.com: What is the background for this study?
Response: The goal of this study was to develop a non-invasive, prognostic biomarker that can address the worldwide clinical dilemma of over-treating low-risk prostate cancers. To accomplish this we developed highly accurate proteomics assays in urines collected after a digital rectal examination (termed post-DRE urines).
Dr. Thomas Kislinger[/caption]
Thomas Kislinger, PhD
Senior Scientist at the Princess Margaret Cancer Centre
University Health Network
Associate Professor
Department of Medical Biophysics
University of Toronto
MedicalResearch.com: What is the background for this study?
Response: The goal of this study was to develop a non-invasive, prognostic biomarker that can address the worldwide clinical dilemma of over-treating low-risk prostate cancers. To accomplish this we developed highly accurate proteomics assays in urines collected after a digital rectal examination (termed post-DRE urines).
Dr. Peter Ganz[/caption]
Peter Ganz, MD
Chief, Division of Cardiology
Director, Center of Excellence in Vascular Research
Zuckerberg San Francisco General Hospital
Maurice Eliaser Distinguished Professor of Medicine
University of California, San Francisco
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Ganz: The research described in the JAMA paper involved measuring 1,130 different proteins in nearly 2000 individuals with apparently stable coronary heart disease, who were followed up to 11 years. Initially, two hundred different proteins were identified whose blood levels could be related to the risk of heart attacks, strokes, heart failure and death, and ultimately a combination of nine proteins was selected for a risk prediction model, based on their combined accuracy and sensitivity.
Application of these findings to samples of patients with stable coronary heart disease demonstrated that some of those who were deemed clinically stable instead had a high risk of adverse cardiovascular outcomes, while other patients with the same clinical diagnosis had a very low risk. Thus, individuals who all carried the same clinical diagnosis of stable coronary heart disease had a risk of an adverse cardiovascular event that varied by as much as 10-fold, as revealed by analysis of the levels of the nine proteins in their blood. Given such large differences in risk and outcomes, patients could reasonably opt to be treated differently, depending on their level of risk. We hope that in the future, management of patients with stable angina will at least in part rely on risk assessment based on levels of blood proteins.
Dr. Donald Burke[/caption]
Donald S. Burke, M.D.
Dean of the University of Pittsburgh Graduate School of Public Health
Director of the University of Pittsburgh Center for Vaccine Research
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Burke: At the University of Pittsburgh we developed a unique method for detecting antibodies in the blood of patients in a proof-of-principle study that opens the door to development of simple diagnostic tests for diseases for which no microbial cause is known, including auto-immune diseases, cancers and other conditions.
We used a technique pioneered by co-author Thomas Kodadek, Ph.D., of the Scripps Research Institute, that synthesizes random molecular shapes called “peptoids” hooked onto microscopic plastic beads. The technique can produce millions of molecular shapes. The peptoids are not organic, but if they match to the corresponding shape on an antibody, that antibody will connect to them, allowing the scientist to pull out that bead and examine that peptoid and its corresponding antibody.
My team chemically generated a huge library of random molecular shapes. Then, using blood from HIV-infected patients and from non-infected people, we screened a million of these random molecular shapes to find the ones that bound only to antibodies present in the blood of HIV-infected patients, but not the healthy controls. No HIV proteins or structures were used to construct or select the peptoids, but the approach, nonetheless, successfully led to selection of the best molecular shapes to use in screening for HIV antibodies.
We then resynthesized that HIV-antibody-targeting peptoid in mass and tested it by screening hundreds of samples from the Multicenter AIDS Cohort Study (MACS), a confidential research study of the natural history of treated and untreated HIV/AIDS in men who have sex with men (supported by the National Institutes of Health). Study co-author Charles Rinaldo, Ph.D., chair of Pitt Public Health’s Department of Infectious Diseases and Microbiology and director of the Pittsburgh arm of the MACS, selected the samples, but blinded the testers to which samples were HIV-positive or -negative. The test distinguished between the samples of HIV-positive blood and HIV-negative blood with a high degree of accuracy.
Dr. Gretchen Tietjen[/caption]
Dr. Gretchen Tietjen MD
Professor and Chair of Neurology
Director of UTMC Headache Treatment and Research Program
Director of the UTMC Stroke Program
MedicalResearch.com: What is the background for this study?
Dr. Tietjen : C-reactive protein (CRP) is a well-established biomarker of inflammation. Elevated levels of CRP predict future cardiovascular events, such as myocardial infarction (heart attack) and stroke. Evidence linking higher CRP levels with migraine is limited and results from large population-based studies are conflicting. The National Health and Nutrition Examination Survey (NHANES) data for children and adolescents linked elevated CRP to headache, particularly in girls, and the Women’s Health Study showed an association of CRP with migraine in women over 45 years of age. In the Reykjavik study, CRP levels in persons with migraine were similar to levels in those without migraine. The aim of our study was to examine the relationship of CRP and migraine in a large population-based sample of over 9,000 young adults (24 to 32 years old) from The National Longitudinal Study of Adolescent to Adult Health (Add Health).
Dr. Mathew Jankowich[/caption]
Matthew D. Jankowich, MD
Assistant Professor of Medicine
Alpert Medical School of Brown University
Staff physician at the Providence VA Medical Center
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Jankowich: For some time, endothelin-1 has been known to cause vasoconstriction in the pulmonary circulation, and elevated endothelin-1 levels have been noted in patients with pulmonary arterial hypertension and decompensated congestive heart failure, as well as other advanced disease states. However, endothelin-1 has not been well studied in members of the general population. In our study, we examined plasma endothelin-1 levels in participants in the Jackson Heart Study and the relationship of plasma endothelin-1 levels to pulmonary hypertension, mortality and heart failure. We found increased odds of having pulmonary hypertension, defined as an echocardiography estimation of the pulmonary artery systolic pressure>40mmHg, in those participants with higher plasma endothelin-1 levels. Having higher endothelin-1 levels was also associated with an increased risk of both mortality and heart failure. Those participant with both high endothelin-1 levels (a level in the top 25%) and pulmonary hypertension were at the highest risk of mortality.
Dr. Maria Schwaederle[/caption]
Maria Schwaederle PharmD
Clinical Research Scientist
Center for Personalized Cancer Therapy
UCSD Moores Cancer Center
La Jolla, CA 92093
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Schwaederle: We performed this analysis with experts in the field, including but not limited to Drs Schilsky, Lee, Mendelsohn and Kurzrock, all known for their experience in the area of precision/personalized medicine.
Historically, phase I trials (which are often first in human or highly experimental in other ways) were believed to be examining only toxicity. Our meta-analysis of 13,203 patients shows that in the era of precision medicine, this historical belief needs to be discarded. Second, it is the use of precision medicine that makes this belief outdated.
Indeed, Phase I trials that utilized a biomarker-driven approach that is the essence of precision medicine had a median response rate of about 31%, which is higher than many FDA approved drugs, and this is in spite of the fact that phase I patients are a highly refractory group having failed multiple lines of conventional therapy.
Importantly, however, it was not the use of targeted agents alone that was important. It was the biomarker-based approach where patients are matched to drugs. Without matching, response rates were dismal—about 5%.
Dr. Johannes Neumann[/caption]
Dr. med. Johannes Neumann
Resident physician
University Heart Center Hamburg
Department of General and Interventional Cardiology
Universitätsklinikum Hamburg-Eppendorf
Hamburg
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The early decision making in patients with suspected acute myocardial infarction is important. Current guidelines recommend measurement of cardiac troponin at admission and after 3 hours. In our study we evaluated the performance of a high-sensitivity troponin I assay with a rapid measurement after only 1 hour. We included 1040 patients with new onset chest pain and could show, that a low cutoff concentration of 6 ng/L after 1 hour allows safe rule-out of acute myocardial infarction. The results were comparable to the recommended 3-hour approach and were validated in 2 external cohorts. When using the 99th percentile to rule-out myocardial infarction, as recommended by current guidelines, the negative predictive value was much lower. Furthermore, a troponin I concentration above 6 ng/L in combination with an absolute change of 12 ng/L after 1 hour showed a high positive predictive value for the final diagnosis of myocardial infarction. This allows early decision making after only 1 hour.
Dr. Yvan Devaux[/caption]
Yvan Devaux, PhD
Associate Head of Laboratory
Cardiovascular Research Unit
Department of Population Health
Dr. Jonathan Shoag[/caption]
Jonathan Shoag MD
Urology Resident at
Cornell Department of Urology and
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Dr. Jim Hu[/caption]
Dr. Jim C. Hu MD
Ronald Lynch Professor of Urologic Oncology
Professor of Urology
Director, Lefrak Center for Robotic Surgery
Attending Urologist, New York-Presbyterian Hospital (Cornell campus)
MedicalResearch.com: What is the background for this study?
Response: Prostate Specific Antigen (PSA) is a blood test that is used to detect prostate cancers and to follow a cancer’s response to treatment. PSA was widely implemented as a screening tool for prostate cancer in the early 1990s, and became a routine test during an annual physical for men over 40. Doctors started using it because values above a “normal” threshold were associated with a greater risk of prostate cancer. Following the adoption of PSA screening in the early 1990s, there has been a large increase in the number of men diagnosed with cancer, and a decrease of approximately 50% in the rate of prostate cancer death.
The PLCO trial was a large randomized trial designed and funded by the National Cancer Institute (NCI) to determine the effect of PSA screening on death from prostate cancer. The trial found that men randomized/assigned to prostate cancer screening had the same number of prostate cancer deaths as men in the control group of the trial, arguing that PSA screening does not decrease prostate cancer mortality.
This was a major piece of evidence used by the United States Preventative Services Task Force (USPSTF) to form its 2012 recommendation against PSA screening. The argument was that in spite of the other evidence showing a benefit to PSA testing, including US epidemiologic trends, and another large randomized trial showing PSA screening was effective (the ERSPC), we now had good evidence showing no benefit to PSA testing in the US. Since 2012 we have seen dramatic declines in prostate cancer screening in the US as a result.
Dr. Han Liang[/caption]
Dr. Han Liang PhD
Associate Professor and Deputy Department Chair, Department of Bioinformatics and Computational Biology
The University of Texas MD Anderson Cancer Center
Faculty Member, Baylor College of Medicine
Houston, TX
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Liang: An individual’s sex has been long recognized as a key factor affecting the risk of cancer development and management. However, previous studies on the sex effect have been limited to individual genes, single molecular data types, and single cancer lineages.
We performed a comprehensive analysis of molecular differences between male and female patients in a diversity of cancer types and revealed two sex-effect groups.
One group contains a small number of sex-affected genes, whereas the other shows much more extensive sex-biased molecular signatures. More than half of clinically actionable genes (e.g., therapeutic targets or biomarkers) show sex-biased signatures.
Dr. Stephen Freedland[/caption]
Stephen J. Freedland, MD
Associate Director, Faculty Development Samuel Oschin Comprehensive Cancer Institute
Co-Director, Cancer Genetics and Prevention Program
Director, Center for Integrated Research in Cancer and Lifestyle
Professor, Surgery
Warschaw Robertson Law Families Chair in Prostate Cancer
Cedars-Sinai, Los Angeles
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Freedland: PSA is a marker of prostate pathology. While often used to screen for prostate cancer, it is not prostate specific and can be elevated due to inflammation or enlarged prostate or other reasons. Whether it predicts the development of urinary symptoms is not clear. Among men with minimal to no urinary symptoms, we found that the higher the PSA, the greater the risk of future development of urinary symptoms.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Freedland: The readers should know that if a man has an elevated PSA and a negative prostate biopsy, the higher the PSA, the greater the risk of future urinary symptoms. These are men who may need closer follow-up.
Dr. J. William Harbour[/caption]
Prof. Rudi Beyaert[/caption]
Professor Rudi Beyaert
VIB - Inflammation Research Center Ghent University
Department for Biomedical Molecular Biology Unit of Molecular Signal Transduction in Inflammation
Technologiepark Ghent) Belgium
MedicalResearch.com: What is the background for this study? What are the main findings?
Prof. Beyaert: The interest of my laboratory is in understanding the molecular mechanisms that are responsible for the development of inflammatory diseases such as Crohn's disease, multiple sclerosis, rheumatoid arthritis and also psoriasis, which is the topic of the published study. We already know that genetic factors can determine the onset of these inflammatory diseases, but how these genetic factors drive an inflammatory response is still largely unclear. We were specifically interested in the CARD14 gene, because patients with mutations in CARD14 have a very high chance to develop psoriasis. Psoriasis-associated mutations in CARD14 trigger specific skin cells (keratinocytes) to produce and release large amounts of other proteins that recruit and activate specific white blood cells driving an inflammatory response. We now discovered that this effect is dependent on the physical interaction of CARD14 with the protease MALT1 in keratinocytes, leading to the activation of its enzymatic activity and the MALT1-mediated cleavage and inactivation of a number of cellular proteins that normally keep our immune system in check. Treatment of skin cells with small compound MALT1 inhibitors prevents the CARD14-induced production of several pro-inflammatory mediators.
Dr. Anne Poljak[/caption]
Dr Anne Poljak
Leader of the Proteomics Group
Centre for Healthy Brain Ageing (CHeBA)
UNSW, Australia
MedicalResearch.com: What is the background for this study?
Dr Poljak: Amyloid-beta (Aβ) peptides are found in abundance in the plaque particles which build up in the Alzheimer’s brain and small blood vessels of the brain, and are therefore considered hallmark features of Alzheimer’s disease. However they are also found in blood which is a convenient body fluid for sampling purposes. We therefore wished to assay them in plasma samples from one of our longitudinal population based studies of older age individuals (70 – 90 years) – the Centre for Healthy Brain Ageing’s 



