Genetic Research
20 Jul Family History of Lupus Is Strong Risk Factor For Lupus and Other Autoimmune Diseases
MedicalResearch.com Interview with: Dr. Changfu Kuo MD PhD Division of Rheumatology, Orthopaedics, and Dermatology School of Medicine, University of Nottingham, Nottingham, England Division of Rheumatology, Allergy, and Immunology Chang Gung Memorial Hospital, Taoyuan, Taiwan Medical Research: What is the background for this study? What are the main findings? Dr. Kuo: Systemic lupus erythematosus (SLE) is a prototype of autoimmune disease with features like autoantibody production and multiple target organ damage. SLE can affect any part of the body and the course of the disease is highly diverse and unpredictable. SLE can occur at any age and affect both females and males with a sex ratio of 9 to 1. Familial predisposition has been recognised as a risk factor previously and heritability of SLE has been estimated to be 66%. However, previous reports are often based on less robust sampling strategies and case ascertainment which generally depend on hospital records, self-reported diagnosis and disease registries, therefore limiting generalisability. The previous estimates of heritability are overestimated, due to a lack of consideration of shared environmental contribution. This study utilised a unique health insurance database that provides information on the whole population of Taiwan and permits determination of spouse and first-degree relatives. Over 23 million people were included in this study. Furthermore, through inclusion of SLE status of the spouse in our analyses the study is also able to examine how much of familial clustering results from genetic versus shared environmental factors. Overall the familial relative risk is 16.92. The genetic contribution to SLE susceptibility is estimated to be 44%. In addition to SLE, other autoimmune diseases are also more prevalent in individuals with a family history of SLE.20 Jul Genetic Risk Score Did Not Predict Recurring Events After Myocardial Infarction
MedicalResearch.com Interview with:
Christopher Labos MD CM, MSc FRCPC
Division of Epidemiology, Biostatistics and Occupational Health
McGill University
Montreal, Quebec
Canada
Medical Research: What is the background for this study? What are the main findings?
Response: There have been great advances in the field of genetics in recent years. Especially in cardiology, a number of genetic variants have been identified that are associated with cardiovascular disease. But it is not clear how useful these variants are in terms of predicting future evens in patients that have already suffered a myocardial infarction. What we found in our study is that a genetic risk score composed of the 30 most common genetic variants associated with cardiovascular diseases was not useful in predicting recurrent events in the first year after a patient suffered a myocardial infarction.
17 Jul Gene Therapy May Stop Blindness From Retinitis Pigmentosa
MedicalResearch.com Interview with:
Professor Robert E MacLaren MB ChB DPhil FRCOphth FRCS
Nuffield Laboratory of Ophthalmology
Nuffield Department of Clinical Neurosciences
Oxford Biomedical Research Centre, University of Oxford,
Moorfields Eye Hospital & UCL NIHR Biomedical Research Centre for Ophthalmology
London, UK.
Medical Research: What is the background for this study? What are the main findings?
Prof. MacLaren: The study shows that gene therapy can be used to release a protein in the eye that arrests the development of retinitis pigmentosa, a blinding disease caused by degeneration of the retina. The study was performed in mice which had a similar genetic defect to that found in humans with the disease. The mice also had fluorescent green “glow in the dark” light sensing cells known as cones, which we could see and count by looking into the eye – like counting stars in the night sky. By counting the green fluorescent cones we were able to work out the exact dose of gene therapy needed to keep these cells alive indefinitely. The study was funded by Fight for Sight, a UK charity that supports finding cures for eye diseases.
17 Jul RNA in Sperm Could Be Biomarkers of Male Fertility
MedicalResearch.com Interview with:
Stephen A. Krawetz, Ph.D.
Associate Director C.S. Mott Center for Human Growth and Development,
Charlotte B. Failing Professor of Fetal Therapy and Diagnosis,
Department of Obstetrics and Gynecology,
Center for Molecular Medicine and Genetics,
Wayne State University School of Medicine,
Detroit, MI, 48201
Medical Research: What is the background for this study? What are the main findings?
Dr. Krawetz: The current study developed over approximately the past 20 years of work in my laboratory. In the mid 1990s, along with David Miller, we independently discovered that sperm contain RNA. This was followed by our joint publication in The Lancet that began to describe the RNAs in normal fertile males along with our paper in Nature that showed that RNA was delivered to the oocyte at fertilization. Following these studies we assessed the ability of RNAs to be used as markers of morphologically abnormal sperm (teratozoospermia). My laboratory then had the opportunity to explore the complexity of the population of sperm RNAs using Next Generation Sequencing. We recently began the translation of this work from the bench to bedside which takes us to the current paper in Science Translational Medicine that was a multi-institutional collaborative effort. Members of the team include Dr. Meritxell Jodar, Edward Sendler, Robert Goodrich, from my laboratory, along with Dr. Clifford L. Librach, Dr. Sergey I. Moskovtsev, and Sonja Swanson - CReATe Fertility Center, University of Toronto; Dr. Russ Hauser -Harvard University and Dr. Michael P. Diamond, Georgia Regents University. Here we tackled the issue of idiopathic infertility, that is, unknown infertility, since the couple appears normal in all respects. We specifically framed our study as the contribution of the male and female as a couple towards the birth of a healthy child focusing on male idiopathic infertility within the setting of a Reproductive Clinic. Representative publications from my laboratory that outline this part of my research program appear below.
1) Jodar, M., Sendler, E., Moskovtsev, S. Librach, C., Goodrich, R., Swanson, S., Hauser, R., Diamond, M. and Krawetz, S.A. (2015) Absence of sperm RNA elements correlates with idiopathic male infertility. Science Translational Medicine, 7(295):295re6.
2) Sendler, E., Johnson, G.D., Mao, S., Goodrich, R.J., Diamond, M.P., Hauser, R., and Krawetz, S.A. (2013) Stability, Delivery and Functions of Human Sperm RNAs at Fertilization. Nucleic Acids Research 41:4104-4117. PMID: 23471003
3) Platts, A.E., Dix, D. J., Chemes, H.E., Thompson, K.E., Goodrich, R., Rockett, J. C., Rawe, V.Y., Quintana, S., Diamond, M.P., Strader, L.F. and Krawetz, S.A. (2007) Success and failure in human spermatogenesis as revealed by teratozoospermic RNAs. Human Molecular Genetics. 16:763-773. PMID: 17327269
4) Ostermeier, G.C., Miller, D., Huntriss, J.D., Diamond, M.P. and Krawetz, S.A. (2004) Delivering spermatozoan RNA to the oocyte. Nature 429:154. PMID: 15141202
5) Ostermeier, G.C., Dix, D.J., Miller, D., Khatri, P. and Krawetz, S.A. (2002) Spermatozoal RNA profiles of normal fertile men. The Lancet. 360:773-777. PMID: 12241836
17 Jul Genetic Testing Can Detect, Protect Patients Prone To Thoracic Aortic Aneurysm
MedicalResearch.com Interview with:
John A. Elefteriades, MD
William W.L. Glenn Professor of Surgery
Chief of Cardiothoracic Surgery
Director, Aortic Institute at Yale-New Haven
Yale University School of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Elefteriades: The race to map the human genome was declared completed in 2003, at a cost of 3 billion dollars for the international collaborative university group and 300 million dollars for Craig Venter at Celera. Whole exome sequencing can now be performed at a cost of only several thousand dollars per individual. So, whole exome sequencing (also called Next Generation Sequencing) can now be applied to understand and treat diseases of many organ systems.
In this study, we applied whole exome sequencing to study over 100 patients with thoracic aneurysm.
In the late 1990s, both Dr. Diana Milewicz in Texas and our group at Yale had determined that many thoracic aortic aneurysms were genetically transmitted. Dr. Milewicz went on to identify many of the causative mutations. In this study, we were able to look, by whole exome sequencing performed on saliva, for all 21 mutations known to cause thoracic aortic aneurysm--all at one time in one comprehensive genetic test. We were able to protect patients with the most serious discovered mutations by early surgery, the need for which could not otherwise have been apparent.
13 Jul Shape Differences of Brain Important For Individualized Precision Medicine
MedicalResearch.com Interview with: Chun Chieh Fan Ph.D student USCD Cognitive Science and Professor Anders M. Dale Ph.D Department of Cognitive Science, Multimodal Imaging Laboratory, Department of Radiology University of California, San Diego School of Medicine La Jolla, CA 92037 Medical Research: What is the background for this study? What are the main findings? Response: The shape of human skull is closely associated with the ancestral background. Forensics uses it for determining ethnicity. Anthropologists use it to infer neuroanatomical change in human evolution. Yet it is unclear the inner content of skull, human brain, contains how much information about individual’s ancestry. Our study found that different continental ancestries are associated with unique cortical folding patterns. Even for contemporary populations in modern day USA, a melting pot of ethnicities, cortical folding patterns are highly predictive of the percentage of each continental ancestry, as determined based on the person’s genotype. These shape differences between ancestral heritages are not necessarily related to brain function. It is highly possible that the shape differences are resulting from a random process accumulated along human history, without significant functional consequences.08 Jul Hormonal and Reproductive Factors Influence Uterine Cancer Risk in Lynch Syndrome
MedicalResearch.com Interview with:
Aung Ko Win, MBBS MPH PhD
Research Fellow
NHMRC Early Career Clinical Research Fellow
Centre for Epidemiology and Biostatistics
Melbourne School of Population and Global Health
The University of Melbourne VIC 3010
Australia
Medical Research: What is the background for this study? What are the main findings?
Response: About 2-5% of uterine cancer are associated with an underlying genetic condition mainly Lynch syndrome. Lynch syndrome is caused by a mutation in one of the mismatch repair genes. At least 1 in 1000 people in the population have a mutation that causes Lynch syndrome and these people have a very high risk of cancers mainly bowel and uterine cancers. One in three women with a mutation in one of the mismatch repair genes are likely to develop a uterine cancer in their lifetime. The only way to reduce the risk of uterine cancer for these women is to remove the uterus. There is no current recommendation for screening method to detect uterine cancer early. Almost nothing is known about if and how lifestyle factors and hormonal factors can modify their risk of uterine cancer.
By studying 1128 women with a mutation that causes Lynch syndrome who were recruited from Australia, New Zealand, Canada and the USA, we found that later age at first menstrual cycle, having one or more live births, and using hormonal contraceptive use for one year or longer were associated with a lower risk of uterine cancer.
11 Jun Oncotype DX Breast Cancer Assay Quickly Adopted Under Medicare Guidelines
MedicalResearch.com Interview with:
Michaela Dinan, Ph.D.
Duke Clinical Research Institute and Duke Cancer Institute
Department of Medicine
Duke University School of Medicine
Durham, North Carolina
Medical Research: What is the background for this study? What are the main findings?
Response: I think it will be critical to further explore the implications of Oncotype DX breast cancer assay (ODX testing) in women with breast cancer. The ODX test helps predict which cancers will be more aggressive as well as guide recommendations as to which patients would most likely benefit from chemotherapy. I think we should look to see what impact this test is really having on the use of chemotherapy and its associated costs and outcomes for real-world breast cancer patients.
05 Jun Only Some KRAS Gene Mutations Linked To Worse Prognosis In Colon Cancer
MedicalResearch.com Interview with:
Timothy Michael Pawlik, M.D., M.P.H., Ph.D.
Chief, Division of Surgical Oncology
Professor of Surgery
John Hopkins
Medical Research: What is the background for this study?
Dr. Pawlik: The prognosis of patients operated on for colorectal liver metastasis (CRLM) is currently defined by various “traditional” clinicopathologic factors. However the insight that they provide is incomplete. KRAS is the most common oncogene of the RAS family and is reported in up to 30 to 40% of patients with colorectal liver metastasis. As a result, KRAS mutational status recently attracted a lot of attention as a potential prognostic factor in colorectal liver metastasis. However, overall mutant KRAS status (compared to wild type) correlated with worse survival only in some studies.
We hypothesized that the specific KRAS activating mutations (codon 12 and codon 13) confer different biologic behaviors to the tumor and in turn, account for different (if any) prognostic values. The different proportions of each KRAS specific mutation could determine whether the overall mutational status would be associated with worse survival. In our view, the different proportions of specific mutations in various cohorts could account for the variability of the outcomes in different studies.
Medical Research: What are the main findings?
Dr. Pawlik: Our results showed that only codon 12 KRAS mutations conferred a worse prognosis whereas codon 13 ones did not. Furthermore, we examined the different point mutations that constitute codon 12 mutations and we found that among G12A, G12D, G12V, G12C and G12S KRAS point mutations, only G12V and G12S were independent prognostic factors of worse survival. That confirmed our hypothesis that only some of the point mutations do have a significant prognostic role and that the relative incidence of those mutations could determine if overall KRAS mutational status would be associated with worse survival in a certain cohort.
04 Jun First X-Chromosome Related Cause of Male Infertility Identified
MedicalResearch.com Interview with:
Alexander N Yatsenko, MD, PhD
Assistant Professor,
Department of OBGYN and Reproductive Science,
Magee-Womens Research Institute,
University of Pittsburgh, PA
Pittsburgh, PA 15213
Medical Research: What is the background for this study? What are the main findings?
Dr. Yatsenko: The known causes of male infertility not due to physical obstruction are usually because of sex-chromosome defects, such as deletions of the Y chromosome or duplication of the entire X chromosome in Klinefelter syndrome. Eight times out of 10, conventional genetic testing doesn’t reveal a chromosomal problem and infertility is considered idiopathic. We wanted to try to find other genetic reasons for the problem.
We found a deletion in part of the DNA coding of the testis-expressed gene 11 (TEX11) on the X-chromosome, which men inherit from their mothers. The alteration caused meiotic arrest, meaning the precursor cells could not properly undergo meiosis. We also found similar TEX11 gene mutations and meiotic arrest in two out of 49 men diagnosed with idiopathic azoospermia in Pittsburgh or at a Poland infertility clinic, and in five out of 240 infertile men assessed at a collaborating Andrology clinic in Muenster, Germany. These genetic findings were confirmed on protein level using patients’ testis biopsies.
03 Jun Myriad Presents Data on Expanded Cancer Genetics and Chemotherapy Susceptibility Testing
MedicalResearch.com spoke with
Dr. Johnathan Lancaster, MD, Ph.D. at the 2015 ASCO meeting in Chicago.
Dr. Lancaster is the new Vice President of Medical Affairs for Oncology, Myriad Genetic Laboratories, at Myriad. Dr. Lancaster jointed Myriad in February 2015 after twelve years at the Moffitt Cancer Center. Prior to Moffitt, Dr. Lancaster was medical director of the Gynecologic Dysplasia Clinic at Duke University Medical Center in Durham, NC, where he also completed his residency and fellowship training.
MedicalResearch.com: Can you tell us a little more about your background? How did you come to work at Myriad?
Dr. Lancaster: My background and interests lie at the intersection of patient care and the molecular and genetic understanding of cancer. I completed my MD and Ph.D. in molecular genetics at the University of Wales, and then came to Duke for a research fellowship and residency training in Obstetrics & Gynecology. I spent twelve years as a gynecology-oncology surgeon.
At the Moffitt Cancer Center, I ran a research lab attempting to understand the molecular and genetic underpinnings of ovarian cancer development and progression. Our translation research attempted to identify markers, or microRNAs, that help predict ovarian tumors’ response to chemotherapeutic agents.
I also have experience in the management and financial issues facing medicine and health care. While at Moffitt, I was president of the 350-member Moffitt Medical Group, deputy physician-in-chief and director of the Center for Women's Oncology.
The opportunity at Myriad Genetics allows me to utilize my experience in all three interests, clinical care, research and management, to contribute to a broader mission of cancer treatment and prevention.
MedicalResearch.com: What studies are being presented at ASCO this year by Myriad associated researchers?
Dr. Lancaster: There are 19 abstracts presented by Myriad at ASCO 2015, which is a testament to the emphasis Myriad places on basic and translational research (Myriad reinvests $300-400 of the proceeds from every clinical test performed into research). The studies center around two main themes:
1: An enhanced panel of genes, called MyRisk, to test for increased risk of hereditary cancers.
2: The use of Homologous Recombination Deficiency (HRD) testing and score, called MyChoice, which helps clinicians determine which patients may respond best to some chemotherapeutic agents.
MedicalResearch.com: What does the MyRisk panel offer over and above the information learned from BRAC1/2 testing? Why should a patient or clinician want this testing performed?
Dr. Lancaster: The MyRisk panel tests for 25 state-of-the-art genes with the goal of determining who may be at increased risk for certain malignancies even if they are BRAC1/2 negative. The typical patient is one who has a family history of cancer but may have been told she doesn’t have the ‘breast cancer gene’ because she is BRAC1/2 negative. We now know that up to 50% of these patients may carry other genes that make them more susceptible to cancer. Panel testing allows clinicians to identify many more patients at risk for cancer who would have been missed with more traditional BRAC1/2 testing alone.
31 May Genes Associated With High Triglycerides May Be Protective Against Diabetes
MedicalResearch.com Interview with:
Yann Klimentidis Ph.D.
Assistant Professor
Mel and Enid Zuckerman College of Public Health
University of Arizona
Medical Research: What is the background for this study? What are the main findings?
Dr. Klimentidis: Previous studies have hinted at the possibility that genes which are associated with higher triglyceride levels may also be associated with lower type-2 diabetes. We set out to test this hypothesis in multiple prospective cohort studies, in European-Americans and in African-Americans. We found that on a collective basis, the alleles which are associated with higher triglycerides are also associated with reduced type-2 diabetes risk. We also identified some individual genetic variants which are driving this trend.
26 May Unrecognized Carriers of Genetic Variants May Have Serious Medical Issues
MedicalResearch.com Interview with :
Prof. Alexandre Reymond
Director, Center for Integrative Genomics
University of Lausanne
Lausanne Switzerland
MedicalResearch : What is the background for this study?
Prof. Reymond: Though a subset of recurrent DNA copy number variants (differing numbers of copies of genetic sequence at locations in the genome; CNVs) with rare population prevalence are known to have strong impact on carrier’s health, up to now their association with phenotypes such as intellectual disability has been almost exclusively evaluated in clinical context using individuals ascertained for diagnostics of developmental disorders. Thus the contribution of these genetic variants to health, cognition and life quality in the general population remains unclear. We used a population biobank, that of Estonia (Estonian Genome Center, University of Tartu), which contains samples from 52,000 adult participants (representative 5% of the country’s adult population), a British birth cohort (The Avon Longitudinal Study of Parents and Children; ALSPAC) and two more population-based cohorts from the USA and Italy to explore the consequences of CNVs in presumptively healthy populations.
MedicalResearch : What are the main findings?
Prof. Reymond: Rare recurrent CNVs known to be causative for specific syndromes (termed genomic disorders) have a global population prevalence of around 1%. Contrary to popular assumption that carriers of these syndromic CNVs identified in unselected, but assumed to be healthy, adult population cohorts are asymptomatic, we found that they are associated with unrecognized, but serious clinical sequelae.
Additionally our results showed that individually rare (less than 1 in 2000 individuals) but collectively common (around 10% of population) intermediate-size CNVs are negatively associated with carriers’ educational attainment. Altogether our results suggest that the life quality of at least 1 of 40 people might be negatively affected by rare CNVs.
22 May Obesity Leads To Reversible Changes In Diabetes-Predisposition Genes
MedicalResearch.com interview Dorota Kaminska, MSc Department of Clinical Nutrition University of Eastern Finland MedicalResearch: What is the background for this study? What are the main findings? Response: The prevalence of obesity is increasing worldwide, making it one of the biggest health problems currently facing both developed and developing countries. Obesity is considered a primary risk factor for developing type 2 diabetes. While the majority of people with type 2 diabetes are obese, most of obese people do not develop diabetes, indicating that obesity is not the only risk factor for type 2 diabetes. Both obesity and type 2 diabetes are multifactorial complex diseases that are caused by a combination of genetic, environmental, and lifestyle factors. Results from twin studies suggest that genetic factors explain 50% to 90% of the variance in body mass index (BMI) and from 45% to 85% of the diabetes risk. However genetic variations identified by genome wide association studies (GWAS) explain only 2-4% of the obesity risk and 5-10% of the type 2 diabetes risk. Several options have been debated to be a source of so called “missing heritability”, including, among others, structural DNA variations, gene-gene and gene-environment interactions, epigenetic modifications and RNA splicing. We used adipose tissue samples from Kuopio Obesity Surgery (KOBS), very low calorie diet (VLCD), Metabolic Syndrome in Men (METSIM) and European Network on Functional Genomics of Type 2 Diabetes (EUGENE2) studies to determine alternative splicing pattern of selected genes. The study focused on determining the effects of obesity and weight loss on alternative splicing of metabolically active genes (TCF7L2 and INSR). We showed that alternative splicing of both genes is dysregulated in obesity and type 2 diabetes, resulting in impaired insulin action in adipose tissue. Additionally we demonstrated, that obesity induced changes in splicing can be reversed by weight loss induced by gastric bypass surgery or very low calorie diet. Furthermore, the study identified alternatively spliced genes in the genomic regions associated with obesity risk, demonstrating that splicing of the MSH5 gene in subcutaneous fat is regulated by weight loss. The study also found that body mass index is a main determinant of TRA2B, BAG6 and MSH5 splicing in subcutaneous fat; however, the functional consequences of this finding require further investigation. These findings imply that the obesity-associated gene variants might act through regulation of splicing which in turn might underlie the pathogenesis of obesity in individuals carrying the risk variants.20 May Do Our Genes Influence Our Work Ethic and Leadership Ability?
MedicalResearch.com Interview with:
Wendong Li, Ph.D.
Assistant professor of psychological sciences
Department of Psychological Sciences
Kansas State University
Manhattan, KS
Medical Research: What is the background for this study? What are the main findings?
Dr. Wen-Dong Li: There has been a "nature versus nurture" debate in leadership: Are leaders born or made? In academia, research on trait theories of leadership has shown that important individual characteristics such as personality traits are predictive of whether one is a leader or not (leadership role occupancy or emergence). One author of this paper, Dr. Arvey conducted twin studies showing that about 30% of the individual differences in leadership is attributable to individual differences in their genetic makeup. But so far, little research has examined whether specific genes are involved and no research has examined the pathways linking genes to leadership.
This is where this research came in. We found that a dopamine transporter gene, DAT1 was involved in genetic influences on leadership role occupancy, but through two opposing pathways. One pathway is through proactive personality: DAT1 10-repeat allele was negatively related to proactive personality, which in turn was positively associated with leadership role occupancy. The negative indirect effect was significant. On the other hand, DAT1 was positively related to (moderate) rule breaking, which was positively associated with leadership role occupancy. The overall relationship between DAT1 and leadership was not significant. Thus we call it a mixed blessing because the two opposing mechanisms offset each other.
16 May Genetic Cell Cycle Proliferation Score Stratifies Risk For Prostate Cancer
MedicalResearch.com Interview with: Michael Brawer, M.D. Vice president of Medical Affairs Myriad Genetic Laboratories Editor’s Note: Dr. Brawer spoke with MedicalResearch.com regarding two studies presented by Myriad Genetic Laboratories at the American Urological Association's 2015 Annual Meeting, May 15 2015 on the use of the Clinical Cell Cycle Risk (CCR) Score or Prolaris Test...
15 May Gene Expression Signatures May Help Differentiate Sepsis From Non-Infectious Inflammation
MedicalResearch.com Interview with: Timothy E Sweeney, MD PhD Resident, General Surgery Postdoc, Khatri Lab, Bioinformatics Stanford University Medical Research: What is the background for this study? What are the main findings? Dr. Sweeney: Sepsis is defined as the presence of systemic inflammation due to infection. Systemic inflammation can be caused from many things, such as trauma, surgery, thrombosis, autoimmunity, etc. It can also be caused by infection. On the other hand, infection does not necessarily cause systemic inflammation, either: a person can get a minor infection, like strep throat, and not have a systemic response. It's the intersection of severe inflammation (a syndrome called SIRS) with infection that defines sepsis. In general surgery, we frequently see patients after traumatic injury or surgery who are having an inflammatory response (ie, fevers, fast heart rate, high white blood cell count, etc). But it's not clear whether this inflammatory response is a reaction to the trauma or surgery, or whether there might be an infection brewing that is causing the reaction. Identifying the inflammatory response doesn't require many special tests-- it's easy to spot. So we know which patients have inflammation and which do not. What is difficult is determining the root cause of the inflammation, and, in particular, whether there is an infection present that needs treatment with antibiotics. Current diagnostics for infection (not sepsis) are either slow (like blood cultures, which can take 24-72 hours to return) or not highly accurate (like procalcitonin). We sought to define a better test that could specifically differentiate between people with sterile inflammation, and people with inflammation due to infection (sepsis). By integrating gene expression data from multiple publicly available cohorts, we were able to find a set of 82 genes that are significantly differently expressed between these two groups. We then used an algorithm called a greedy forward search to find a subset of 11 genes that were most diagnostic for sepsis.11 May Genetic Variants Explain Differences in Age Of Onset Of Huntington’s Disease Symptoms
Posted at 20:08h
in Author Interviews, Genetic Research, Karolinski Institute, Nature, Neurological Disorders
[caption id="attachment_14115" align="alignleft" width="150"]
Photo: Ulf Sirborn[/caption]
MedicalResearch.com Interview with:
Kristina Bečanovič Ph.D.
Department of Clinical Neuroscience
Karolinska Institutet, Stockholm, Sweden
Medical Research: What is the background for this study?
Dr. Bečanović: While the symptoms normally debut in middle-age, there is wide individual variation in how Huntington disease manifests itself, and even though two people carry the exact same genetic mutation that codes for the huntingtin protein, there can be up to a 20-year difference in onset of motor symptoms. This suggests that genetic variants, transcription factors and environmental factors could contribute to the observed differences in disease expressivity. As the identification of regulatory factors of the huntingtin gene would be targets for therapeutic intervention, we set out to study the regulation of the huntingtin gene as it has not been well-known which factors regulate the expression levels. We were interested in identifying both genetic variants and transcription factors that are of importance for gene regulation. We therefore used DNA from Huntington disease patients to study the regulation of the huntingtin gene promoter in cells.
09 May Emotional Reactivity May Be Genetically Predisposed
MedicalResearch.com Interview with:
Rebecca Todd Ph.D.
Assistant Professor University of British Columbia
Department of Psychology
Centre for Interactive Research on Sustainability
Vancouver, BC
Medical Research: What is the background for this study? What are the main findings?
Dr. Todd: This study brings together two lines of research. First, a couple of years ago my colleagues and I reported that in general people literally see emotional aspects of the world as more vivid - as if they burn more brightly on the eye - than mundane things. We call this effect emotionally enhanced vividness, or EEV. Here we wanted to look at how this phenomenon of emotionally enhanced vividness might differ between individuals.
Second, in another previous study we found that people who carry a very common variation in the ADRA2b gene, which influences levels of norepinephrine (a neuromodulator in the brain that is important to the stress response and for emotional influences on memory) were more likely to have their attention captured by emotionally relevant aspects of the world. We also found that how arousing they perceived an event to be at the time it happened predicted how well they remembered it better than for people who did not carry this variation. Here we continued to examine what is unique to this group of people by testing to see if they showed higher levels of the other phenomenon we had found, emotionally enhanced vividness, and what patterns of brain activation would play a role.
07 May Deficient Calcium Channels Weaken Immune Response To Chronic Infections
MedicalResearch.com Interview
Dr. Ludovic Desvignes PhD.
Assistant Professor, Departments of Medicine and Pathology
NYU Langone Medical Center
MedicalResearch: What is the background for this study?
Dr. Desvignes: This study is the result of a collaboration at NYU Langone Medical Center, between the laboratories of Dr. Stefan Feske and Dr. Joel Ernst, my mentor. Dr. Feske and colleagues had developed a mouse model of rare, inherited mutations he had identified in infants. These mutations occur in the genes for STIM1 and ORAI1, which are crucial for calcium flux in cells of the immune system. The young patients affected by these mutations suffer from severe, recurrent and chronic infections that often cause death before their first birthday. In particular, some of these patients cannot control infection with BCG, which is a normally innocuous strain of mycobacteria administered to protect against tuberculosis (TB). TB is a chronic infection and one of the leading causes of infection-related death worldwide. Going into this study, Dr. Feske and colleagues knew that without functional calcium channels, immune cells do not function properly. However, they did not fully understand how these channels contribute to immune responses to infectious pathogens in a living organism and in particular, for pathogens that cause chronic infections such as TB. This is why Dr. Ernst and I collaborated with Dr. Feske and provided him with our clinical and research expertise in TB.
MedicalResearch: What are the main findings?
Dr. Desvignes: Dr. Feske’s mice are genetically engineered to lack STIM1 in a certain type of immune cells, known as T cells or T lymphocytes. We infected these mice with Mycobacterium tuberculosis, the bacterium causing TB. Mycobacterium tuberculosis causes chronic infection by manipulating the immune system even in healthy people. The first very surprising result of our study was that mice lacking calcium flux in T cells handled acute TB fairly well. Only during the chronic phase of infection did they become unable to control mycobacterial growth and developed a strong inflammation in their lungs, which was due to an infiltration by different types of immune cells, including T cells. We discovered that the accumulation of STIM1-deficient T cells in the lungs resulted from the cells’ inability to die, which is a normal mechanism to limit an immune response and prevent excessive inflammation.
Another immune control mechanism that failed in the absence of STIM1 is mediated by a subset of T cells called induced regulatory T cells, or iTreg cells. These cells are essential to prevent normal immune responses from going “overboard” by suppressing the functions of other immune cells, including T cells. We found that calcium signals are required for the development of iTreg cells and that their numbers were strongly reduced in the lungs of infected STIM1-deficient mice. We therefore think that the lack of iTreg cells in the absence of STIM1 contributes to the severe lung inflammation in chronic TB.
The third finding that really surprised us was that T cells accumulating in the lungs of STIM1-deficient mice produced large amounts of a protein called interferon gamma. While interferon gamma is required to control Mycobacterium tuberculosis, it is also a very potent promoter of inflammation and too much of it can lead to tissue damage. Dr. Feske and colleagues had previously observed that calcium fluxes promote the production of interferon gamma in T cells cultured in vitro and we expected the STIM1-deficient T cells to be defective in the production of that protein. During chronic TB, however, calcium signaling turned out to be not only dispensable for the production of interferon gamma by T cells but it was actually required to limit its production and thus, to control inflammation.
07 May Genes Identified That May Be New Drug Targets In HER2 Breast Cancer
MedicalResearch.com Interview with:
Ahmad M. Khalil, PhD
Assistant professor, Department of Genetics and Genome Sciences
Case Western Reserve University School of Medicine
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Khalil: This study aimed to identify other genes that work synergistically with the oncogene HER2 in HER2positive (HER+) breast cancer. The gene HER2 is amplified in those patients, which results in excess activities that promote uncontrolled cell growth. There are drugs that target HER2 and diminish its activity. However, these drugs can work initially, but patients relapse; or sometimes, the drugs don't work at all in some patients.
Thus, by identifying other genes that work synergistically with the HER2 gene, we now have more genes to target by various drugs or compounds to destroy the tumor. The challenge was how to identify the key genes that work synergistically with HER2, especially in human subjects. To that end, we used clinical samples from a clinical trial of a drug that is known to inhibit HER2 activity to identify those genes. To further refine our list, we used cell culture models of the disease to also inhibit HER2. By combining those data sets, we identified 44 protein-coding genes.
Next, we wanted to make sure that those genes stand a third independent filter. For that part, we interrogated those 44 genes in HER2+ tumors vs matched normal tissues from The Cancer Genome Atlas database — a collection of hundreds of tumors and normal tissues. Of the 44 genes, 35 genes passed this third filter. By examining the known functions of those genes, we can deduce that those genes work cooperatively with HER2 to promote carcinogenesis.
There are currently known drugs that target some of those genes. We will use these drugs in combination with a drug that target HER2 to determine if the combination works better at destroying the tumor entirely.
Lastly, we found that a special type of genes that we previously discovered, called lincRNAs, could also affect the oncogenic activity of HER2. These lincRNAs can also be targeted with HER2 to eliminate the tumor.
05 May More Powerful Gene Vector Aims To Restore Vision In Inherited Blindness
MedicalResearch.com Interview with:
Professor James Bainbridge, MA, PhD, FRCOphth
Professor of Retinal Studies, UCL Institute of Ophthalmology
NIHR Research Professor, NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of OphthalmologyConsultant Ophthalmologist, Moorfields Eye Hospital NHS Foundation Trust
Medical Research: What is the background for this study? What are the main findings?
Prof. Bainbridge : Leber Congenital Amaurosis (LCA) is one of the most common causes of inherited, untreatable blindness in children. There are at least 14 different types of Leber Congenital Amaurosis of which LCA Type 2 (LCA2), caused by defects in the gene RPE65, affects around one in 100,000 people worldwide. Evidence from animal studies support that LCA2 may be amenable to treatment with RPE65 gene replacement therapy.
The main findings of this phase I/II clinical trial confirm our preliminary findings (published in NEJM, 2008) that gene therapy can improve night vision. Improvements peak within the first 12 months after treatment but then decline during the three-year follow-up period which is consistent with the published results and interim findings from other studies of RPE65 gene therapy.
02 May Your Genes May Explain Mosquitoes’ Preference For Your Odor
MedicalResearch.com Interview with:
G. Mandela Fernández-Grandon PhD
Natural Resources Institute,
University of Greenwich,
Chatham, United Kingdom
Medical Research: What is the background for this study?
Response: People often wonder why, when they are out with their friends or family, one person seems to get ravaged by mosquitoes but others come away relatively bite free. Mosquito bites can be a nuisance to many of us but they are no trivial matter. Mosquitoes are one of the most serious threats to public health through the transmission of diseases such as malaria, dengue fever, yellow fever, chikungunya and others.
We knew that mosquitoes rely on odour to find their hosts but until now the link between our body odour and genes had only been shown using human sniffers1. In a strictly controlled laboratory environment, we were able to present the odours of individuals in identical and non-identical twin pairs to mosquitoes allowing them following the odour stream of whichever they found to be more attractive.
Medical Research: What are the main findings?
Response: Mosquitoes are equally attracted to identical twins in a pair but with non-identical twins they display a preference for one individual.
The ability of mosquitoes to distinguish non-identical twins but not identical twins suggests a genetic basis for our odour profile, a genetic difference which plays a role in whether we get bitten more or less than others.
30 Apr Knowledge Of Gene Mutation For Hereditary Carcinoid May Allow Earlier Detection
Posted at 14:23h
in Author Interviews, Cancer Research, Gastrointestinal Disease, Genetic Research, NIH
MedicalResearch.com Interview with:
Dr. Stephen Wank MD
Digestive Diseases Branch, NIDDK
National Institutes of Health, Bethesda, Maryland
MedicalResearch: What is the background for this study?
Dr. Wank: Small intestinal carcinoids are rare and difficult to diagnose because symptoms may be absent or mistaken for more common diseases. Because carcinoids usually grow slowly over several years before spreading or causing symptoms, patients often seek medical attention late with advanced, incurable disease. However, when diagnosed at an early stage, carcinoid can be surgically cured. Presently, there are no long-term effective therapies for surgically non-resectable disease. Although carcinoids occur sporadically, there have been reports of family clusters (more than one blood relative with carcinoid). Hereditary small intestinal carcinoid has not been recognized as a disease and causative genetic factors have not been identified in either sporadic cases or families with multiple affected members.
If small intestinal carcinoid occurs in families on a hereditary basis, we hypothesized that asymptomatic relatives in families with carcinoid are at a high risk of harboring an undiscovered tumor. To test this, we established a clinical research protocol at the National Institutes of Health in Bethesda, Maryland to screen asymptomatic relatives in families with at least two cases of small intestinal carcinoid in the hope of detecting their tumors at an early surgically curable stage. If successful in our endeavor, we would improve the outcome of the disease in these asymptomatic relatives and position ourselves to discover the genetic basis for their disease. Understanding the gene mutations causing small intestinal carcinoid would allow us to screen for the disease with a blood test, help us understand what causes the disease, and treat the disease with specific targeted therapies.
29 Apr Rapid Genome Sequencing Helps Pinpoint Diagnosis In Ill Newborns
MedicalResearch.com Interview with:
Stephen F. Kingsmore MB ChB BAO DSc FRCPath
Dee Lyons/Missouri Endowed Chair in Genomic Medicine,
Children’s Mercy - Kansas City
Medical Research: What is the background for this study?
Response: The background to this study is that genetic diseases are the leading cause of death in infants and, especially, in infants in neonatal intensive care units. Making a molecular (etiologic) diagnosis of the specific genetic disease is critical for optimal care and decision making for acutely ill infants who are likely to have such diseases. However there are over 5000 known genetic diseases and their presentations overlap considerably in infants. Until now it has not been possible to make timely diagnoses in these infants.
Medical Research: What are the main findings?
Response: Rapid whole genome sequencing is a new way of making a genetic disease diagnosis in acutely ill newborns in neonatal intensive care units. It appears to be effective for diagnosis.
27 Apr Polygenic Risk Score Improves Breast Cancer Prediction
MedicalResearch.com Interview with:
Nasim Mavaddat M.B.B.S. MPhil PhD PhD
Centre for Cancer Genetic Epidemiology
Department of Public Health and Primary Care
University of Cambridge, Cambridge, UK
MedicalResearch: What is the background for this study?
What are the main findings?
Dr. Mavaddat: Recent large-scale genome wide association analyses have led to the discovery of genetic variation- called single nucleotide polymorphisms (SNPs) associated with breast cancer risk. Individually these variants confer risks that are too small to be useful for risk prediction. But when combined as a single score, called a polygenic risk score (PRS), this score may be used to stratify women according to their risk of developing breast cancer. This stratification could guide strategies for screening and prevention.
Our study was a large international collaboration involving 41 research groups from many different countries and included 33,673 breast cancer patients and 33,381 controls. We found that the genetic variants act more or less independently, and that the more risk variants a woman has the higher her risk of breast cancer. When women were ranked according to their PRS, women with scores in the top 1% had a threefold increased risk of breast cancer. This translates into an absolute risk of breast cancer of 29% by age 80. By contrast, women with the lowest 1% scores had a risk of 3.5%.
The PRS was effective in stratifying women with and without a family history of breast cancer, so that highest risk was for women with a family history and a high PRS. Finally, we showed that the PRS was better at predicting the risk of ER-positive breast cancer (potentially relevant to the application of risk stratification to chemoprevention for example, with tamoxifen, raloxifene or aromatase inhibitors).
There has been much debate as to whether genomic profiles are useful for individual risk prediction, especially in the context of the preventative strategies available at the present time. The estimates provided in this study will help inform these debates.
23 Apr Gene Expression Profile Improves Melanoma Risk Assessment
MedicalResearch.com Interview with:
Pedram Gerami, M.D.
Associate Professor of Dermatology
Director, Melanoma Research
Northwestern Skin Cancer Institute
Northwestern University
MedicalResearch: What is the basis and background for performing this study?
Dr. Gerami: Most of the existing literature shows that Sentinel Lymph Node Biopsy (SLNB) will identify 25 to 35 percent of patients who will ultimately die of metastatic melanoma. Hence while SLNB is reported to be the strongest predictor of outcome for melanoma, the vast majority of patients who ultimately die of metastatic melanoma have a negative Sentinel Lymph Node Biopsy result. Hence in this study we aimed to determine whether a GEP assay developed by Castle bioscience could be used independently or in conjunction with SLNB to better detect those patients who are at high risk for developing metastatic disease and dying from melanoma.
MedicalResearch: What are the findings of the study?
Dr. Gerami: Our study, which examined the use of a Gene Expression Profile (GEP) assay developed by Castle Biosciences and Sentinel Lymph Node Biopsy alone and in combination in a multi-center cohort of 217 patients, demonstrated that the use of the GEP identified more than 80 percent of patients who develop melanoma
Combining the two methods showed that patients predicted to be high risk based on the GEP test alone had similar rates of disease progression whether they were SLNB positive or negative. Patients who were SLNB negative and predicted to be low risk using the GEP test had lower rates of disease progression than the SLNB negative group as a whole.
21 Apr Targeted Melanoma Panel Identifies Genetic Subsets of Melanoma
Posted at 23:42h
in AACR, Author Interviews, Genetic Research, Melanoma, NYU/NYMC, Personalized Medicine, Wistar
MedicalResearch.com Interview with:
Melissa Wilson, MD, PhD
Assisstant Professor
Perlmutter Cancer Center
NYU Langone Medical Center
New York, NY
Medical Research: What is the background for this study? What are the main findings?
Dr. Wilson: Metastatic cutaneous melanoma is an extremely aggressive form of skin cancer. Traditionally, it has been characterized by clinicopathologic characteristics. More recently, melanoma tumors have also been stratified by common somatic mutations for which targeted therapies have been developed or are under investigation, including BRAF, NRAS and KIT. In addition to somatic mutations, aberrant intracellular signaling pathways and cell cycle disruption contribute to melanoma pathogenesis. Indeed, recent next generation sequencing studies have identified a number of new genes involved in melanomagenesis. A comprehensive evaluation and understanding of concurrent and mutually exclusive mutations in tumors has been lacking. Therefore, we developed a comprehensive custom targeted capture of 108 genes previously implicated in melanoma pathogenesis. We used the targeted panel to perform massively parallel sequencing on 94 well-established human melanoma cell lines, 67 patient-derived xenografts (PDX), and 5 cell lines made from PDX, all untreated.
Samples were clustered based on deleterious mutations. Eighty-three percent of samples had deleterious mutations in the MAPK signaling pathway (including BRAF, RAS) and NF1. Ten percent of samples had PI3K pathway mutations which were predominantly associated with BRAF mutations. TP53 was found to be mutated in 24% of the samples and were also associated with mutations in the MAPK pathway. Mutations in chromatin remodeling genes were mutually exclusive with each other, but were associated with BRAF and NRAS mutations. Of particular interest, five of the 10 NF1mutated samples harbored likely deleterious mutations in MAP3K5 or MAP3K9, suggesting the potential involvement of JNK signal transduction pathway in a cohort of samples.
21 Apr Epigenetic Changes May Account For How Some Lymphoma Tumors Change Over Time
MedicalResearch.com Interview with: Olivier Elemento, PhD Associate Professor Head, Laboratory of Cancer Systems Biology Department of Physiology and Biophysics Institute for Computational Biomedicine Weill Cornell Medical College New York, NY, 10021 Medical Research: What is the background for this study? What are the main findings? Dr. Elemento: In many cancer patients, initial treatment with chemotherapy or targeted therapy...