Correlation Between MIR-559 Polymorphism and Susceptibility of Gastric Cancer in Northern Iran

Gastric cancer is the fourth most common malignancy and the third leading cause of cancer death worldwide. Micro RNAs are single stranded molecules which can inhibit the expression of mRNA by binding to the 3’ UTR region. It has been demonstrated that miRNAs control several cancer related mechanisms. Several studies revealed that miRNAS play key roles in many cancers such as gastric cancer. A single nucleotide polymorphism (SNP) is the most common type of genetic variation which may occur every 100-300 bases. It has been recognized that SNPs might play role in cancer. Since miRNAs are small functional units, single base changes (i.e. SNP) in both the precursor elements as well as the mature miRNA sequence may result in the evolution of new microRNAs through altering their biological function. The relation between structural changes and ectopic expressions of miRNA, diagnosis and incidence of gastric cancer has been previously proven. Here, we investigated whether the miR-559 rs58450758 polymorphism affects the susceptibility to gastric cancer.This study included 65 patients with confirmed Gastric cancer and 70 control cases. The genomic DNA was extracted from peripheral blood using a GPP solution kit.Genotyping of miR-559 rs58450758 was performed by PCR-RFLP method. The amplicon was subsequently subjected to digestion using TaaI restriction enzyme.No significant difference was found between patients and control group in either allele frequencies or genotype distributions of the rs58450758 SNP. Accordingly, it seems that there is no correlation between the incidence of gastric cancer and mir-559 rs58450758 in northern Iran.