Single nucleotide polymorphisms in miRNA binding sites (miR-SNPs) are associated with cancer risk. We assessed the relationship between five miR-SNPs in the 3' untranslated region (3'-UTR) of RYR3 (rs1044129), KIAA0423 (rs1053667), C14orf101 (rs4901706), GOLGA7 (rs11337), and KRT81 (rs3660) and the risk of breast cancer (BC). The CC genotype of rs3660 located in the 3'-UTR of KRT81 was identified for its association with lower BC risk (odds ratio, 0.093; 95% confidence interval, 0.045-0.193; p = 0.000). Immunnochemical analysis and Renilla luciferase reporter assays indicated that the CC genotype of KRT81 was associated with lower expression of KRT81 (p < 0.05). The subsequently functional analysis showed that knockdown the KRT81 could inhibit proliferation and promote apoptosis of the MDA-MB-231 BC cells (p < 0.05) with monocyte chemotactic protein-1 (MCP-1) deregulation. Meanwhile, KRT81 overexpression could promote the proliferation and inhibit the apoptosis of MCF-7 BC cells (p < 0.05). Our data demonstrated that the KRT81 expressional change modulated by rs3660 miR-SNP could modify the carcinogenesis of BC, thereby KRT81 would be a new target for BC treatment.
Keywords: BC; KRT81; miR-SNP; rs3660.