Association study of miR-100, miR-124-1, miR-218-2, miR-301b, miR-605, and miR-4293 polymorphisms and the risk of breast cancer in a sample of Iranian population.

MicroRNAs (miRNAs) regulate genes expression by directly binding to the 3' untranslated region (3'UTR) of specific target mRNAs. Single nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) are proposed to be important in the development of breast cancer (BC). In the present study, we conducted a case-control study with 266 BCE patients and 288 control women to examine the possible association of miRNAs polymorphisms (miR-100 rs1834306, miR-124-1 rs531564, miR-218-2 rs11134527, miR-301b rs384262, miR-605 rs2043556, and miR-4293 rs12220909) with BC susceptibility. Genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The findings showed miR-218-2 rs11134527 variant increased the risk of BC (OR = 7.70, 95%CI = 3.84-15.43, P < .0001, GA vs GG and OR = 6.86, 95%CI = 3.47-13.57, P < .0001, A vs G). Regarding miR-301b rs384262 polymorphism, we observed that this variant significantly increased the risk of BC (OR = 3.12, 95%CI = 2.20-4.45, P < .0001, AG vs AA and OR = 2.22, 95%CI = 1.68-2.93, P < .0001, G vs A). Our findings did not support an association between miR-100 rs1834306, miR-124-1 rs531564, miR-605 rs2043556 and miR-4293 rs12220909 polymorphism and the risk of BC. In conclusion, the finding showed that miR-218-2 rs11134527 and miR-301b rs384262 variant might contribute to increase the risk of BC in a sample of Iranian population. Additional studies with larger sample sizes and different ethnicities are necessary to confirm our finding.