miR-581-Related Single Nucleotide Polymorphism, rs2641726, Located in MUC4 Gene, is Associated with Gastric Cancer Incidence.

MUC4 is aberrantly expressed in several carcinomas including breast, colon, ovarian, lung, prostate, stomach and pancreatic cancers. MUC4 can regulate cell apoptosis negatively and facilitate stomach tumorigenesis. In this research, we aimed to evaluate the possible association between rs2641726 (C > A) polymorphism of MUC4 and gastric cancer risk in the Iranian population. In this case-control study, we collected blood samples from 168 gastric cancer patients and 66 healthy subjects. Allele-specific primer polymerase chain reaction method was applied to genotype rs2641726 in the obtained DNA samples. This study demonstrated that rs2641726 C allele was significantly associated with the incidence of gastric cancer, odds ratio = 3.382, 95% confidence interval: 1.840-6.217 (P < 0.001). Furthermore, the distribution of this risk allele was highly enriched in the samples with stage III. In silico studies revealed that the C allele of rs2641726, located within MUC4 3'UTR, is potential to attenuate the interaction between miR-581 and MUC4 mRNA. This disturbing effect, which might result in higher expression of MUC4 oncoprotein, was proposed for the mechanism of action of the rs2641726 risk allele. rs2641726 C allele is significantly enriched in gastric cancer specimens. The attenuating effect of this allele on miR-581 and MUC4 interaction might be a potential mechanism of action by which C allele imposes its oncogenic impact.