Non-coding single nucleotide polymorhpisms (SNPs) account for over 85% of the genotype-phenotype associations identified in genomewide association studies (GWAS), yet we understand almost nothing about their functional mechanisms. Numerous lines of evidence demonstrate that regulatory SNPs play causal roles in many complex human phenotypes. GWAS associations are enriched for variants associated with gene expression levels (eQTLs) and within cis-regulatory elements (CREs). Because eQTLs and CREs are often functional in a subset of cell types, and because a particular cell type is often of interest for a disease, it is critical that analyses of GWAS-eQTL overlap consider cell specificity. Our long term research objective is to determine, for every non-coding SNP, if it is functional in a particular cell type and, if so, the specific mechanism by which it functions. In order to reach this goal, we need to have in hand a large set of cell specific, causal functional SNPs from which we can begin to generalize; the results from current eQTL studies are typically insufficient because they are not always relevant for a cell type of interest, they identify tag SNPs instead of the causal SNP, and they do not integrate CREs. Our objectives in this proposal are to develop statistical models to identify, quantify, and functionally interpret cell specific eQTLs in cis and trans, and to experimentally validate causal variant predictions using novel massively parallel CRE reporter assays.
In Aim 1, we will develop multivariate Bayesian regression models that will improve power for eQTL detection, improve the interpretibility of eQTL cell specificity, and identify the CREs through which each SNP functions.
In Aim 2, we will develop structured sparse latent factor models to identify cell specific gene coexpression modules that will be used to identify trans-eQTLs while simulataneously controlling for hidden confounding variables.
In Aim 3, we will develop and apply massively parallel CRE reporter assays to validate thousands of predicted causal variants that underlie eQTL associations. With such a large collection of cell specific causal eQTNs and CREs in hand, we hope to mechanistically interpret GWAS associations, identify cancer-causing somatic mutations, and specify novel drug targets for human disease.

Public Health Relevance

Genome-wide association studies have identified thousands of genetic variants that contribute to the risk of developing disease. However, we have not often translated these results into a mechanistic understanding of how diseases manifest, which is important for risk screening and drug design. To make this translation possible, we propose to identify causal variants that affect disease risk by regulating gene expression, the tissues in which they are active, and the genomic regulatory mechanisms that are disrupted by each variant.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH101822-03
Application #
8878357
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Addington, Anjene M
Project Start
2013-08-01
Project End
2017-06-30
Budget Start
2015-07-01
Budget End
2016-06-30
Support Year
3
Fiscal Year
2015
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Genetics
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
McDowell, Ian C; Barrera, Alejandro; D'Ippolito, Anthony M et al. (2018) Glucocorticoid receptor recruits to enhancers and drives activation by motif-directed binding. Genome Res 28:1272-1284
Agrawal, A; Chou, Y-L; Carey, C E et al. (2018) Genome-wide association study identifies a novel locus for cannabis dependence. Mol Psychiatry 23:1293-1302
Zhang, Mingfeng; Lykke-Andersen, Soren; Zhu, Bin et al. (2018) Characterising cis-regulatory variation in the transcriptome of histologically normal and tumour-derived pancreatic tissues. Gut 67:521-533
Trizzino, Marco; Park, YoSon; Holsbach-Beltrame, Marcia et al. (2017) Transposable elements are the primary source of novelty in primate gene regulation. Genome Res 27:1623-1633
Collado-Torres, Leonardo; Nellore, Abhinav; Kammers, Kai et al. (2017) Reproducible RNA-seq analysis using recount2. Nat Biotechnol 35:319-321
Benítez-Buelga, Carlos; Baquero, Juan Miguel; Vaclova, Tereza et al. (2017) Genetic variation in the NEIL2 DNA glycosylase gene is associated with oxidative DNA damage in BRCA2 mutation carriers. Oncotarget 8:114626-114636
Tukiainen, Taru; Villani, Alexandra-Chloé; Yen, Angela et al. (2017) Landscape of X chromosome inactivation across human tissues. Nature 550:244-248
Chiang, Colby; Scott, Alexandra J; Davis, Joe R et al. (2017) The impact of structural variation on human gene expression. Nat Genet 49:692-699
Gudmundsson, Julius; Thorleifsson, Gudmar; Sigurdsson, Jon K et al. (2017) A genome-wide association study yields five novel thyroid cancer risk loci. Nat Commun 8:14517
Dolan, M Eileen; El Charif, Omar; Wheeler, Heather E et al. (2017) Clinical and Genome-Wide Analysis of Cisplatin-Induced Peripheral Neuropathy in Survivors of Adult-Onset Cancer. Clin Cancer Res 23:5757-5768

Showing the most recent 10 out of 47 publications