title: Population differences in microRNA expression and biological implications.
abstract: Population differences observed for complex traits may be attributed to the combined effect of socioeconomic, environmental, genetic and epigenetic factors. To better understand population differences in complex traits, genome-wide genetic and gene expression differences among ethnic populations have been studied. Here we set out to evaluate population differences in small non-coding RNAs through an evaluation of microRNA (miRNA) baseline expression in HapMap lymphoblastoid cell lines (LCLs) derived from 53 CEU (Utah residents with northern and western European ancestry) and 54 YRI (African from Ibadan, Nigeria). Using the Exiqon miRCURYTM LNA arrays, we found that 16% of all miRNAs evaluated in our study differ significantly between these 2 ethnic groups (pBonferroni corrected< 0.05). Furthermore, we explored the potential biological function of these observed differentially expressed miRNAs by comprehensively examining their effect on the transcriptome and their relationship with cellular sensitivity drug phenotypes. After multiple testing adjustment (false discovery rate (FDR)< 0.1), we found that 55% and 88% of the differentially expressed miRNAs were significantly and inversely correlated with an mRNA expression phenotype in the CEU and YRI samples, respectively. Interestingly, a substantial proportion (64%) of these miRNAs correlated with cellular sensitivity to chemotherapeutic agents (FDR< 0.05). Lastly, upon performing a genome-wide association study between SNPs and miRNA expression, we identified a large number of SNPs exhibiting different allele frequencies that affect the expression of these differentially expressed miRNAs, suggesting the role of genetic variants in mediating the observed population differences.
authors.affiliation: Section of Hematology-Oncology, University of Illinois at Chicago, Chicago, IL, USA. rhuang@medicine.bsd.uchicago.edu
authors.forename: R Stephanie
authors.initials: RS
authors.lastname: Huang
authors.forename: Eric R
authors.initials: ER
authors.lastname: Gamazon
authors.forename: Dana
authors.initials: D
authors.lastname: Ziliak
authors.forename: Yujia
authors.initials: Y
authors.lastname: Wen
authors.forename: Hae Kyung
authors.initials: HK
authors.lastname: Im
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Claudia
authors.initials: C
authors.lastname: Wing
authors.forename: Shiwei
authors.initials: S
authors.lastname: Duan
authors.forename: Wasim K
authors.initials: WK
authors.lastname: Bleibel
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Cox
authors.forename: M Eileen
authors.initials: ME
authors.lastname: Dolan
mesh_terms: D044383:Black People / Q000235:genetics*; D002460:Cell Line; D020869:Gene Expression Profiling; D005787:Gene Frequency; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D060148:HapMap Project; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D059467:Transcriptome; D044465:White People / Q000235:genetics*
chemical_list: D035683:MicroRNAs