Increased Risk of Gastric Cancer with VNTR Polymorphism of SIRT3 Gene

Background and Gastric cancer is the most common cancer associated with high mortality worldwide. One of the genes that is down-regulated in gastric cancer, is the SIRT3 that encodes the histone deacetylase enzyme. There is a variable number tandem repeat (VNTR) polymorphism in the intron 5 of SIRT3 gene and evidence shows that expression of SIRT3 gene increases by increase in the number of repeats. According to the deregulation of SIRT3 gene expression in gastric cancer and the effect of intron 5 VNTR polymorphism in the transcription, we investigated the association between intron 5 VNTR polymorphism of SIRT3 gene and the risk of developing gastric cancer.
A case-control study was performed in 116 patients with gastric cancer (attending Isfahan Omid Hospital, Iran) and healthy controls (n= 116). After DNA extraction, all samples were genotyped using PCR and electrophoresis techniques and the results were analyzed applying logistic regression and Chi-square tests.
In addition to the alleles that have been reported so far, alleles with 8 and 9 repeats were observed too, in this study. The results showed that genotype 4-1 increases significantly the risk of gastric cancer (P=0.028, OR= 13.00).
Some variants of intron 5 VNTR polymorphism SIRT3 gene is associated with risk of developing gastric cancer.