Abstract
The purpose of the article: The MIR137 gene acts as a tumor-suppressor gene in colon and gastric cancers. The aim of this study was to investigate the association of functional variable number tandem repeat (VNTR) polymorphism rs58335419 locating in the upstream of the MIR137 gene with the risk of colon and gastric cancers. Materials and methods: Totally, 429 individuals were contributed in the study, including 154 colon and 120 gastric cancer patients and 155 healthy controls. The target VNTR was genotyped using PCR and electrophoresis for all samples. Statistical analysis was performed using SPSS 21.0 software and by T, χ2 and logistic regression tests. Results: Excluding the rare genotypes, our results showed that genotype 3/5 (95% CI = 1.08-3.73, OR = 2.01, p = 0.026) significantly increased the risk of colon cancer but not gastric cancer (95% CI = 0.88-3.30, OR = 1.70, p = 0.114). Also, in the stratification analysis for VNTRs and sex, genotypes 3/4 (95% CI = 1.00-6.07, OR = 2.46, p = 0.049) and 3/5 (95% CI = 1.25-7.18, OR = 2.99, p = 0.014) significantly increased the risk of colon cancer in men but not in women. In addition, all genotypes including the rare genotypes as a group, significantly increase the risk of gastric (95% CI = 1.14-3.00, OR = 1.85, p = 0.012) and colon (95% CI = 1.38-3.43, OR = 2.17, p = 0.001) cancers compared to the genotype 3/3 as a reference. Conclusion: The results show that increasing the copy of VNTR in the MIR137 gene, increases the risk of colon and gastric cancers and can serve as a marker for susceptibility to colon and gastric cancers.