胃癌及其癌前病变中细胞凋亡及其调控基因的表达

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

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p5 3、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、2 0例癌前病变、2 4例正常粘膜中的凋亡细胞和p5 3、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 0 1) ,癌前病变组高于胃癌组 (P <0 0 1)。p5 3、bcl- 2、c -myc蛋白在胃癌中阳性率分别为 6 0 9%、6 7 4%、73 2 % ,均高于正常粘膜组(P <0 0 1) ;在癌前病变中 3种蛋白阳性表达率分别为 40 %、95 %、5 8 8% (P <0 0 1)。胃癌中p5 3、bcl- 2蛋白阳性细胞凋亡指数分别低于阴性组 (P <0 0 5 ) ,c -myc蛋白阳性组细胞凋亡指数高于阴性组 (P <0 0 1)。结论 :细胞凋亡调控异常在胃癌发生中可能起重要作用。p5 3、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。

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.