Fas gene expression and its relationship with apoptosis in human gastric carcinoma and precancerous lesions

Objective To explore the relationship between Fas gene expression and the frequency of apoptosis in different stages of malignant transformation of gastric epithelium in precancerous lesions and gastric carcinomas. Methods In situ hybridization and immunohistochemical methods were used to study the frequencies of expression of Fas gene in 10 cases of normal gastric mucosa, 72 chronic gastritis and 53 gastric carcinoma. Meanwhile, in situ apoptotic cell detection was adopted to detect the apoptotic cells in these lesions, and the number of apoptotic cells was compared with the Fas gene expression in each case. Results Fas gene didn't express in normal gastric mucosa. In situ hybridization revealed that the positive frequency of Fas gene expression in intestinal metaplasia was significantly higher than that in atrophic gastritis and gastric carcinoma(P0.01 and P 0.05), and the expression rate at the protein level of Fas gene products as detected by immunohistochemical method in intestinal metaplasia was significantly higher than that in atrophic gastritis,gastric dysplasia and gastric carcinoma ( P 0.01 and P 0.05). There was no significant difference between the positive rates obtained by these 2 methods. Comparing the Fas expression and apoptotic cell number in these specimens, the apoptotic index in Fas expression positive group was higher than that in Fas negative group ( P 0.01). Conclusion Results suggest that Fas gene can promote apoptosis in gastric carcinoma and its precancerous lesions. The abnormal regulation of apoptosis may play an important role in the pathogenesis of gastric carcinoma.