胃粘膜癌前病变Hp感染与bax蛋白表达及细胞凋亡的关系

Relationship of bax protein expression with Helicobacter pylori infection and apoptosis in gastric precancerous lesions of gastritis patients

目的 研究幽门螺杆菌 (Hp)感染后胃粘膜癌前病变中bax蛋白表达状态及其与细胞凋亡的关系 ,了解Hp在胃癌发生过程中的作用。方法 采用免疫组织化学等方法检测 83例经病理证实为慢性胃炎病人胃粘膜上皮细胞中bax蛋白的表达情况 ,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 在浅表性胃炎、萎缩性胃炎、肠化生及异型增生中 ,bax蛋白表达率分别为 2 6 .6 7%、45 .45 %、70 .0 0 %、5 6 .2 5 % ,bax蛋白在肠化生组织中的表达率显著高于浅表性胃炎 (P <0 .0 1)。Hp感染者bax蛋白表达率为 6 4.2 8% ,显著高于未感染者的 2 9.6 2 % (P <0 .0 1)。在萎缩、肠化生及异型增生等癌前病变中 ,Hp感染者与未感染者bax蛋白表达率分别为 70 .2 1%及 33.33% (P <0 .0 1)。凋亡细胞原位检测结果显示 ,bax蛋白表达阳性肠化生和异型增生组织中的凋亡细胞指数显著高于bax蛋白阴性组 (P <0 .0 5及P <0 .0 1)。结论 Hp感染对bax蛋白表达有一定的影响 ,bax基因对胃粘膜上皮细胞凋亡具有促进性调控作用 ,Hp感染可促进bax蛋白表达增加 ,这可能是Hp感染诱导胃粘膜上皮细胞凋亡的机制之一。

Objective To study the expression of bax protein and its relationship with apoptosis in precancerous lesions after Helicobacter pylori (Hp) infection for the role of Hp in the progression of gastric carcinogenesis. Methods The expression rates of bax protein in gastric epithelial tissues from 83 histopathologically proven chronic gastritis patients were detected with immunohistochemical staining. In situ apoptotic cell detection method was employed to detect the apoptotic cells in these tissues, and the number of apoptotic cells was compared with the bax gene expression in each case. Results The expression rates of bax protein were 26.67%, 45.45%, 70.00% and 56.25% respectively for chronic superficial gastritis, chronic atrophic gastritis, intestinal metaplasia and dysplasia, with that of intestinal metaplasia significantly higher than that in chronic superficial gastritis ( P <0.01). The positive rates of bax protein were markedly higher in patients infected with Hp than those without (64.28% vs 29.62%). In the precancerous lesions of atrophy, intestinal metaplasia and dysplasia, the expression rates of Hp infected patients were significantly higher (70.21%) than those uninfected patients (33.33%, P <0.01). The apoptotic index in bax expression positive intestinal metaplasia and dysplasia tissues was higher than that in bax negative tissues ( P <0.01 and P <0.05). Conclusion Results indicate that Hp enhances the expression of bax gene which can promote the apoptosis in gastric precancerous lesions. This may be one of the mechanisms by which Hp infection induces the apoptosis of gastric epithelial cell.