Evaluation of CpG-SNPs in miRNA promoters and risk of breast cancer

Abstract CpG-SNPs in gene promoter regions are proposed to be associated with multiple diseases. To date, few studies have focused on the associations between CpG-SNPs in miRNA promoters and the risk of breast cancer. In this study, 138 miRNAs differentially expressed between breast cancer and non-cancer tissues (fold change >2, P P  = 0.034; rs155247: adjusted OR = 0.83, 95% CI: 0.74–0.93, P  = 0.002; rs62382272: adjusted OR = 1.24, 95% CI: 1.04–1.47, P  = 0.016). eQTL analysis showed that these three SNPs were correlated with the expression of the related miRNAs in TCGA breast cancer tissues ( P  = 0.006,0.009,0.001 for rs1190983, rs155247, and rs62382272). Furthermore, rs1190983 was found to be associated with CpG site (cg20488673) methylation (meQTL) ( P  = 0.004), which was in turn correlated with miR-342 expression ( P  = 0.016). These findings indicated that the three CpG-SNPs in the promoters of miRNAs were likely to possess important biological functions to breast cancer in the Han Chinese population.