Aim To investigate the effects of Helicobacter pylori(Hp) infection and CagA gene on the gastric epithelial cell proliferation and apoptosis, and investigate the mechanisms of Hp increasing the risk of development of gastric cancer.Methods Endoscopic gastric mucosal biopsies were taken from 127 patients(chronic superficial gastritis,CSG; chronic atrophic gastritis,CAG; chronic atrophic gastritis with intestinal metaplasia,CAGIM; dysplasia,DYS; gastric cancer,GC) and 14 normal subjects(NS).The gastric antral epithelial cell proliferation was evaluated by ki-67 immunohistochemical technique, apoptosis cells in the gastric mucosa were quantitated after terminal deoxynucleotidyl transferase mediated dUTP nick end-labelling and Hp CagA gene was detected by polymerase chain reaction(PCR).Results Ki-67 labelling index(LI) and apoptosis index(AI) of Hp positive patients were significantly higher than that of Hp negative patients or normal controls( P <0.05 and P<0.01) .The LI and AI in Hp positive CSG patients were significantly higher than that in Hp negative CSG patients ( P<0.01); there was no significant difference between the patients with Hp infection and without Hp infection of the other four groups.Patients infected with CagA + Hp had significantly higher LI and much lower AI than that infected with CagA - Hp( P<0.05 ).The AI and LI had a positive correlation in Hp positive or negative CSG group and NS group, and a negative correlation in GC group.There was no correlation between LI or AI and the severity of gastritis.Conclusions Hp induced gastric epithelial proliferation and apoptosis predominantly in the early stage of Hp infection.CagA +Hp and CagA - Hp had different ability of inducing proliferation and apoptosis.Hp infection might lead to the imbalance of the AI/LI ratio and ultimately promote the development of gastric cancer.
幽门螺杆菌(Helicobacter pylori,Hp)是一种生长在胃粘膜表面与粘膜层之间的微需氧菌.自1983年 Marshall et al 首次从胃粘膜中分离出 Hp 以来,大量研究表明该菌与慢性胃炎、消化性溃疡密切相关,也与胃癌有一定关系.但人群中Hp 感染率为50%左右,而只有少数 Hp 感染者发展为消化性溃疡甚至胃癌,造成这种反应的差异有两个原因,一是 Hp 毒力的大小,二是人体的防御能力.而 Hp 的毒力又依 Hp 亚型不同而不同,故各地区感染 Hp 的结果也不一样.因此,对 Hp毒力的研究受到重视.
