Mismatch Repair Gene HMLH1 And HMSH2 Expression In Gastric Cancer Tissue And Its Significance

Objective:To investigate the role of mismatch repair gene hMLH1 and hMSH2 in carcinogenesis of gastric cancer, we measured hMLH1 and hMSH2 protein expression in specimens of gastric carcinoma tissues and adjacent 5 cm tissues which from 40 patients with gastric cancer and gastric mucosa of 20 patients with gastritis. Analyze the role of hMLH1 and hMSH2 in gastric cancer pathogenesis. And explored the role of mismatch repair genes hMLH1 and hMSH2 in mechanism of gastric cancer occurrence and development and early diagnosis to provides a theoretical basisMethods:40 specimens of gastric carcinoma tissues, adjacent tissues(male 25, female 15, with an average age of 58.2 years, male to female ratio 5:3),33 cases of pathologically diagnosed adenocarcinoma, mucinous adenocarcinoma 7 cases. None received preoperative chemotherapy and immune therapy. And 20 gastritis mucosa tissue by Gastroscope biopsy(10 cases of chronic superficial gastritis, chronic atrophic gastritis in 10 cases, including 9 males and 11 females, mean age 46.3 years),all the tissues was examined by western-blot method.Result:(1) 10 cases of superficial gastritis mucosa hMSH2 protein expression was lost, the rate of lost expression was 100%,4 cases of atrophic gastritis mucosa was lost the expression of hMSH2 protein, the rate of lost expression was 40%. hMSH2 protein expression in gastric cancer group was significantly higher than the corresponding adjacent group (F=8.798,P=0.004);compared with the gastritis group, the expression of hMSH2 protein in gastric cancer group was significantly increased (F=33.969,P<0.01); adjacent group and gastritis group to the difference was statistically significant (F=28.590,P<0.01).(2) gastritis group and adjacent groups was significantly higher than the expression of hMLH1 protein in gastric carcinoma (F=9.798,P=0.003); gastritis group and the adjacent group no significant differences (F=1.244,P=0.281); gastritis group, superficial gastritis and atrophic gastritis compared no significant differences (F=2.885,P=0.107).(3) gastric cancer patients in all age groups, sex, tumor location, tumor size, invasive depth, histological type, differentiation degree, lymph node metastasis and clinical stage by comparison, hMSH2 and hMLH1 protein expression was no significant difference (P>0.05).Conclusions:(1)hMSH2 protein expression in gastric cancer group was significantly higher than the corresponding adjacent group, compared with gastritis group, the expression of hMSH2 protein in gastric cancer group was significantly increased;(2) the expression of hMLH1 protein in gastritis mucosa and adjacent tissues was significantly higher than the expression in gastric cancer tissue; gastritis group and the adjacent group with no significant difference; gastritis group, superficial gastritis and atrophic gastritis compared no significant differences; (3) hMSH2 and hMLH1 protein expression in patients with different age groups, sex, tumor location, tumor size, invasive depth, histological type, differentiation degree, lymph node metastasis and clinical stage, etc., the difference was no significant;(4)The high expression of hMSH2 may be one of potential makers of gastric cancer:hMLH1 protein may be histological maker predicting gastric cancer occurrence.