Mismatch Repair Gene Hmsh2 And Promoter Methylation And Gastric Cancer

AIM:To detect methylation status of the 5'CpG island locating in the promoter region of hMSH2(mismatch repair genes, MMR) gene and analyze the relationship between DNA hypermethylation status of hMSH2 and the tumorigenic process of gastric carcinoma.Methods:Methylation status of the hMSH2 promoter was examined by methylation specific PCR(MSP) in 40 cases of gastric carcinomas and its adjacent mucosa samples,14 cases of chronic superficial gastritis and 6 cases of chronic atrophic gastritis.Results:hMSH2 methylation was detected in 24 out of the 40 (60%) gastric cancers,15 out of the 40 (37.5%) corresponding cancer-adjacent mucosa tissues,5 out of the 14 (35.7%) chronic atrophic gastritis and no methylation was detected in the 6 chronic non-atrophic gastritis tissues. The methylation status was markedly higher in the gastric cancer than in other tissues(P<0.05). No significant difference was detected among non-cancer tissues. Methylation did not correlate with clinicopathological characteristics of gastric cancer.Conclusion:Methylation in the promoter region of hMSH2 is a main mechanism for the dysfunction of MMR. The dysfunction of MMR plays an important role in the beginning of the gastric cancer not in the development of the gastric cancer.