胃癌及其癌前病变中细胞凋亡及其调控基因的表达

目的:通过观察胃癌及其癌前病变中细胞凋亡及其调控基因p53、bcl-2、c-myc的表达,探讨其在胃癌恶性转化进程中的作用。方法:利用DNA末端标记技术(TdT-mediateddUTP-biotinnickendlabeling,TUNEL法)和免疫组织化学(streptavidin/peroxidase,S-P法),原位观察了46例胃癌、20例癌前病变、24例正常粘膜中的凋亡细胞和p53、bcl-2、c-myc的表达。结果:癌前病变和胃癌中凋亡指数显著高于正常粘膜(P＜0.01),癌前病变组高于胃癌组(P＜0.01)。p53、bcl-2、c-myc蛋白在胃癌中阳性率分别为60.9%、67.4%、73.2%,均高于正常粘膜组(P＜0.01);在癌前病变中3种蛋白阳性表达率分别为40%、95%、58.8%(P＜0.01)。胃癌中p53、bcl-2蛋白阳性细胞凋亡指数分别低于阴性组(P＜0.05),c-myc蛋白阳性组细胞凋亡指数高于阴性组(P＜0.01)。结论:细胞凋亡调控异常在胃癌发生中可能起重要作用。p53、bcl-2蛋白分别抑制细胞凋亡,c-myc蛋白在胃癌中促进细胞凋亡。

Apoptosis and expression of its regulating gene in gastric carcinoma and its precancerous lesions

AIM: To study apoptosis and the involved genes in malignant transformation of gastric carcinoma. METHODS: Apoptotic cell and apoptotic regulating gene p53,bcl-2,c-myc were detected in 46 cases with gastric carcinomas, 20 cases with precancerous lesions and 24 cases with normal mucosa in situ using TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique and immunohistochemical stain. RESULTS: Apoptotic index in precancerous lesion(intestinal metaplasia and dysplasia) and gastric carcinoma were significantly higher than that in normal mucosa( P<0.01 ); The positive expression rate of p53, bcl-2,c-myc protein were 60.9%, 67.4%,73.2% respectively in gastric carcinoma, significantly higher than that in normal mucosa ( P<0.01 ). And they were 40%, 95%, 58.5% respectively in precancerous lesion ( P<0.01 ). CONCLUSION: The abnormal regulation of apoptosis may play an important role in the pathogenesis of gastric carcinoma. p53, bcl-2 proteins may inhibit apoptosis, c-myc protein may induce apoptosis in gastric carcinoma.