Cell-type-specific eQTL of primary melanocytes facilitates identification of melanoma susceptibility genes

Research output: Contribution to journalArticle

Abstract

Most expression quantitative trait locus (eQTL) studies to date have been performed in heterogeneous tissues as opposed to specific cell types. To better understand the cell-type-specific regulatory landscape of human melanocytes, which give rise to melanoma but account for <5% of typical human skin biopsies, we performed an eQTL analysis in primary melanocyte cultures from 106 newborn males. We identified 597,335 cis-eQTL SNPs prior to linkage disequilibrium (LD) pruning and 4997 eGenes (FDR < 0.05). Melanocyte eQTLs differed considerably from those identified in the 44 GTEx tissue types, including skin. Over a third of melanocyte eGenes, including key genes in melanin synthesis pathways, were unique to melanocytes compared to those of GTEx skin tissues or TCGA melanomas. The melanocyte data set also identified trans-eQTLs, including those connecting a pigmentation-associated functional SNP with four genes, likely through cis-regulation of IRF4. Melanocyte eQTLs are enriched in cis-regulatory signatures found in melanocytes as well as in melanoma-associated variants identified through genome-wide association studies. Melanocyte eQTLs also colocalized with melanoma GWAS variants in five known loci. Finally, a transcriptome-wide association study using melanocyte eQTLs uncovered four novel susceptibility loci, where imputed expression levels of five genes (ZFP90, HEBP1, MSC, CBWD1, and RP11-383H13.1) were associated with melanoma at genome-wide significant P-values. Our data highlight the utility of lineage-specific eQTL resources for annotating GWAS findings, and present a robust database for genomic research of melanoma risk and melanocyte biology.

Details

Authors
  • Tongwu Zhang
  • Jiyeon Choi
  • Michael A. Kovacs
  • Jianxin Shi
  • Mai Xu
  • Melanoma Meta Analysis Consortium
  • Alisa M. Goldstein
  • Adam J. Trower
  • D. Timothy Bishop
  • Mark M. Iles
  • David L. Duffy
  • Stuart MacGregor
  • Laufey T. Amundadottir
  • Matthew H. Law
  • Stacie K. Loftus
  • William J. Pavan
  • Kevin M. Brown
  • NISC Comparative Sequencing Program
  • Håkan Olsson (Contributor)
Organisations
External organisations
  • National Cancer Institute, USA
  • University of Leeds
  • QIMR Berghofer Medical Research Institute
  • National Human Genome Research Institute
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology
Original languageEnglish
Pages (from-to)1621-1635
JournalGenome Research
Volume28
Issue number11
Publication statusPublished - 2018 Nov 1
Publication categoryResearch
Peer-reviewedYes