BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260207T201830EST-2328fvGIEI@132.216.98.100 DTSTAMP:20260208T011830Z DESCRIPTION:Hierarchical Bayes Modeling Of Mediation Through High-Dimension al --Omics Data\n\n \n\nDr. Thomas is Professor of Biostatistics in the De partment of Preventive Medicine\, and Verna R. Richter Chair in Cancer Res earch at the University of Southern California\, Keck School of Medicine. He received his Ph.D. from Թ in 1976\, where he continued as a faculty member until his recruitment to USC in 1984. There he served as the Head of the Biostatistics Division until 2013 and co-directed the S outhern California Environmental Health Sciences Center and the Cancer Epi demiology Program in the USC/Norris Comprehensive Cancer Center. His prima ry research interest has been in the development of statistical methods fo r environmental and genetic epidemiology\, with numerous collaborations in both areas. On the environmental side\, he has been particularly active i n radiation carcinogenesis and air pollution health effects research\, not ably as one of the senior investigators on the Southern California Childre n’s Health Study and the Women’s Environmental Cancer and Radiation Exposu re (WECARE) study and as a member of President Clinton’s Advisory Committe e on Human Radiation Experiments. On the genetic side\, he is a coinvestig ator in the NCI’s Colon Cancer Family Registry\, the Genetic Analysis Work shop\, the ENDGAME consortium to develop methods for genome-wide associati on studies\, and past President of the International Genetic Epidemiology Society. Dr. Thomas has numerous publications\, including the textbooks St atistical Methods in Genetic Epidemiology (Oxford University Press\, 2004) and Statistical Methods in Environmental Epidemiology (Oxford University Press\, 2009). He currently directs a program project grant on “Statistica l methods for integrative genomics in cancer.”\n\n\nVarious high-dimension al epigenetic\, transcriptomic\, proteomic\, metabolomic\, and other – omi c data have become available to provide insight into the mediation of gene tic and environmental influences on disease risk through the internal envi ronment. For example\, the “exposome” concept has been implemented using m ass spectrometry metabolomic measurements to capture a broad spectrum of i nternal metabolites of exogenous exposures\, but statistical methods for a nalyzing these and other - omic data are in their infancy. The “Meeting-in -the-Middle” principle aims to identify the subset of metabolites that are related to both exposure and disease. Here\, we introduce a novel hierarc hical Bayes framework for implementing this idea through simultaneous vari able selection on exposure-metabolite and metabolite-disease associations\ , while incorporating external information such as the pathways in which t he different metabolites are thought to act. The approach is validated by simulation and applied to data on hepatocellular carcinoma of the liver in relation to a panel of 125 metabolites and 7 established risk factors fro m a nested case-control study within the EPIC cohort. 15 of the metabolite s yielded Bayes factors for mediation greater that 20 (“strong” evidence)\ , the majority of these with multiple exposures. To explore this phenomeno n further\, we expanded the hierarchical model to include the pathways thr ough which these metabolites act as prior covariates. The strongest associ ations with exposures were found for the class of lysophosphatidylcholines and the strongest with disease for biogenic amines and acylcarnitines. Th ese approaches could be extended to study mediation through multiple types of – omic data. Genetic Epidemiology 2016\;40 (11): 619.\n DTSTART:20170519T130000Z DTEND:20170519T140000Z LOCATION:Room 25\, Purvis Hall\, CA\, QC\, Montreal\, H3A 1A2\, 1020 avenue des Pins Ouest SUMMARY:Duncan Thomas\, PhD\, University of Southern California URL:/mathstat/channels/event/duncan-thomas-phd-univers ity-southern-california-268088 END:VEVENT END:VCALENDAR