Association of rs9122 Polymorphism in the MCC Gene with Increasing the Risk of Gastric Cancer

Abstract Background and Aim: Gastric cancer is one of the most common malignancies in the world. Genetic background is known to be one of the risk factors for gastric cancer. One of the genes that have been shown to be involved in various cancers, including gastric cancer, is the MCC gene. There are many SNPs in the MCC gene in the encoding and regulatory regions, one of which is rs9122, which is in the binding site to several micro-RNAs. The aim of this study was to investigate the association between rs9122 polymorphism in the MCC gene and the risk of gastric cancer. Methods: In this case-control study, following DNA extraction from the blood sample of 214 gastric cancer patients and 211 healthy individuals, genotype of all samples for rs9122 polymorphism were detemined using the RFLP PCR technique (MluI enzyme). The association between this polymorphism with susceptibility to gastric cancer was assessed using SPSS software and logistic regression test. Results: The results of this study showed that the frequency of allele A and G in the control group, was 48.1 and 51.9%, respectively, and the frequency of AA, AG and GG genotypes in this group was 27, 42.2 and 30.8 %. In the patient group, the frequency of allele A and G was 40.7 and 59.3%, respectively, and the frequency of AA, AG and GG genotypes was 23.4, 34.6 and 42%, respectively. The genotype GG increases the risk of gastric cancer (p = 0.071, OR = 1.578, 95% CI= 0.961- 2.592), and allele G is as a risk allele in the gastric cancer (p = 0.029, OR = 1.353, 95% CI 1.031- 1.775). In addition, the genotype GG increased the risk of gastric cancer by comparison with the total of AA + AG genotypes (p = 0.016, OR = 1.630, 95% CI= 1.094- 2.429 ), whereas the sum of AG + GG genotypes was not associated with the risk of gastric cancer (p = 0.386). Conclusion: It seems allele G in the rs9122 polymorphism of MCC gene increase the risk of gastric cancer as a recessive model. Key words: MCC Gene, Gastric Cancer, Single-Nucleotide Polymorphism rs9122.