Single-nucleotide variants in microRNAs associated with breast cancer in women from western Mexico.

MicroRNAs play a key role in regulating gene expression in human cells. Single-nucleotide variants in these molecules have been linked to cancer development, particularly breast cancer (BrC). To analyze the association of three microRNA polymorphisms with the risk of BrC in women from western Mexico. This case-control study included 71 women diagnosed with BrC and 215 women without BrC. Genotypes were determined using a real-time polymerase chain reaction allelic discrimination assay. Multiple genetic models - dominant, recessive, over-dominant, additive, and multiple comparison - were applied to assess the risk. The over-dominant model showed that the C/T genotype of MIR196A2 (rs11614913) is a protective factor against the ductal histological subtype of BrC in women from western Mexico [odds ratio (OR) = 0.4687, 95% confidence interval (CI): 0.2205-0.9963, P = 0.0489]. A protective effect was also observed for the C/A genotype (OR = 0.2612, 95%CI: 0.0900-0.7582, P = 0.0135) and A allele (OR = 0.2826, 95%CI: 0.0993-0.8044, P = 0.0179) of MIR618 (rs2682818). No significant association was found between MIR200C (rs73262897) and BrC risk. The C/T genotype of rs11614913 in MIR196A2, and C/A genotype and A allele of rs2682818 in MIR618, are associated with a protective effect against BrC in women from western Mexico.