Lack of effects of single nucleotide polymorphisms of the DNA methyltransferase 1 gene on gastric cancer in Iranian patients: a case control study.

Abstract

BACKGROUND: Gastric cancer is one of the most common malignant tumors in Iran. Hypomethylation and/or hypermethylation of DNA has been described in gastric cancer and is presumed to be an early event in carcinogeneisis. OBJECTIVE: We therefore hypothesized that single nucleotide polymorphisms of the DNMT1 gene may be associated with the genetic susceptibility to gastric cancer. METHODS: Totals of 200 patients and 200 controls, both of Iranian origin, were studied. Three polymorphisms were genotyped by PCR-RFLP and allele frequencies and genotypes were compared between the cases and controls. Odds ratios were calculated and the interactions between the polymorphisms, age and sex were examined. RESULTS: There were no significant associations between the DNMT1 polymorphisms and gastric cancer. CONCLUSION: We could not show any association between DNMT1 polymorphisms and gastric cancer. Larger sets of polymorphisms and sample sizes are required for future testing of possible associations.