胃癌前组织和胃癌中Fas基因表达及其与细胞凋亡的关系

目的 探讨胃癌组织及胃癌中Fas基因表达状况及其与细胞凋亡的关系。方法 应用原位杂交和免疫组织化学技术检测10例正常胃粘膜、72例慢性胃炎和53例胃癌中Fas基因的表达，并采用凋亡细胞原位检测方法对组织切片中的凋亡细胞进行观察和比较。结果 正常胃粘膜无Fas基因表达。Fas mRNA在肠化生组织中的表达率为75．00％，显著高于萎缩性胃炎（37．50％，P＜0．01）和胃癌（52．83％，P＜0．05）。Fas蛋白在肠化生组织中的表达率为80．56％，显著高于萎缩性胃炎（37．50％，P＜0．01）、异型增生（55．00％，P＜0．05）和胃癌（45．28％，P＜0．01）。X^2检验表明两种方法检测阳性率差异无显著性。凋亡细胞原位检测结果显示，Fas蛋白表达阳性萎缩性胃炎、肠化生和胃癌组织中的凋亡细胞指数显著高于Fas蛋白阴性组（P＜0．05及P＜0．01），Fas蛋白表达状态与细胞凋亡指数呈正相关（r=0．393，P＜0．01）。结论 Fas基因对胃癌前组织及胃癌细胞凋亡具有促进性调控作用，细胞凋亡调控异常在胃癌发病中可能起重要作用。

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(P<0.01 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.