幽门螺杆菌感染与胃癌及癌前病变中PCNA和Bcl-2表达关系的研究

目的:研究幽门螺杆菌(Helicobacter pylori,H.pylori)感染对胃癌及癌前病变患者增殖细胞核抗原(PCNA)和关键性凋亡调节基因Bcl-2蛋白表达的影响,探讨H.pylori可能的致癌机制.方法:应用免疫组化方法测定20例胃癌组织、18例重度异型增生、12例肠上皮化生、24例萎缩性胃炎、16例浅表性胃炎组织中Bcl-2、PCNA蛋白表达情况,快速尿素酶法和HE染色检测H.pylori感染情况.结果:胃癌组H.pylori感染12例,与慢性浅表性胃炎相比差异有显著性(P＜0.05).从浅表性胃炎到胃癌PCNA指数呈递增趋势,各组间差异均有显著性(P＜0.05).浅表性胃炎和萎缩性胃炎组中H.pylori阳性组与H.pyloir阴性组的PCNA LI差异有显著性(P＜0.05),其余各组间H.pylori阳性和H.pylori阴性病例间的PCNA LI差异无显著性.Bcl-2蛋白在异型增生组中的阳性表达率与胃癌、肠上皮化生相比差异无显著性,与慢性胃炎相比差异有显著性.H.pylori阳性组肠上皮化生、异型增生组织中Bcl-2阳性表达率显著高于H.pylort阴性组,它们之间差异有显著性(P＜0.05).结论:H.pylori感染可促使PCNA、Bcl-2蛋白表达增加,H.pylori可能作为促癌剂在胃癌的发生发展中起一定作用.

Study on the correlation between H. pylori infetion and expression of PCNA and Bcl-2 in gastric cancer and precancerous lesion

Objective:To investigate the potential role of infection with Helicobacter pylori( H.pylori )in the development of gastric cancer with increased expression of proliferating cell nuclear antigen(PCNA)and Bcl 2 protein. Methods:Immunohistochemical stain was used to detect the expression of PCNA and Bcl 2 protein in 16 cases of chronic superficial gastritis ,24 cases of chronic atrophic gastritis, 12 cases of intestinal metaplasia,18 cases of severe dysplasia,20 cases of gastric cancer. H.pylori was assessed by using rapid urease staining test combined with HE stain.Results:There was significant difference for infection rates of H.pylori between gastric carcinoma and chronic superficial gastritis group ( P <0.05) . PCNA LI was graduallly increased from superficial gastritis to gastric cancer. There were significant difference among five groups( P <0.05).There was significant difference for PCNA LI in chronic gastritis between H.pylori positive and negative group( P <0.05). The positive rate of Bcl 2 protein expression in gastric carcinoma and precancerous lesions group were significantly higher than that of chronic superficial gastritis group( P <0.05). There was no significant difference for the positive rate of Bcl 2 between dysplasia and gastric cancer or intestinal metaplasia( P <0.05).Expression of Bcl 2 protein in gastric carcinoma and precancerous lesions were significantly higher than that in chronic gastriti ( P <0.05) .Bcl 2 expression level was more intensive in H.pylori positive group when compared with H.pylori negative group in precancerous lesions( P <0.05). Conclusion: H.pylori infection may increase expression of PCNA and Bcl 2 protein,leading to increase of proliferation and depression of apoptosis in gasric epithelia,therefore act as a oncogenic agent in occurence and developement of gastric cancer.