幽门螺杆菌感染对Fas/FasL表达的影响在胃癌发生中的作用

The role of Fas/FasL expression caused by H.pylori in gastric adenocarcinoma.

目的 观察幽门螺杆菌 (Hp)及其不同毒力株 (cagA阳性与cagA阴性株 )感染对胃黏膜上皮细胞Fas/FasL表达的影响 ,进而探讨胃癌的发生机制。方法 胃镜下取胃窦黏膜标本 ,将研究对象按病理结果分为黏膜萎缩组、黏膜萎缩伴轻度不典型增生组、黏膜萎缩伴中度不典型增生组、胃腺癌组 ,黏膜大致正常组为对照组 ,再根据Hp感染情况分为Hp阳性组与阴性组 ,并将Hp阳性组进一步分成cagA阳性组及阴性组 ,共 9组 80例。以快速尿素酶试验、PCR及组织学等三种方法检测Hp ,用PCR方法对Hp进行分型。用免疫组化法检测Fas、FasL等表达情况。 结果 Hp感染率为 6 0 .0 % ,cagA阳性率为 90 .4 7%。非腺癌病人Hp阳性组Fas/FasL表达明显高于Hp阴性组 (P <0 .0 5 ) ,腺癌组Fas/FasL表达明显高于大致正常组及黏膜萎缩、黏膜萎缩伴轻度不典型增生、黏膜萎缩伴中度不典型增生组 (P<0 .0 1)。cagA阳性组Fas/FasL表达与cagA阴性组差异无显著性 (P >0 .0 5 )。 结论 幽门螺杆菌感染后早期即黏膜萎缩阶段已出现Fas、FasL等的表达增加 ,随细胞凋亡的增加 ,黏膜上皮细胞萎缩加重 ,细胞DNA不稳定性增加 ,并出现不典型增生加重 ,Fas、FasL的表达随之增强 ,一旦肿瘤细胞形成 ,Fas/FasL表达进一步增强 ,形成局部免疫豁免区 。

Objective To observe the effects of different H.pylori strains (cagA + and cagA -) infection on Fas/FasL expression and the pathogenesis of gastirc carcinoma. Methods Gastric biopsy specimens were taken from 80 patients, and these patients were divided into 9 groups according to the H E staining and H.pylori infection. H.pylori (+) groups were subdivided into cagA + and cagA - groups. RUT, PCR and histology were used to detect H.pylori and PCR for cagA detection. Immunohistochemical staining was used to detect Fas/FasL expression. Results The infection rate of H.pylori was 60.0%, and rate of cagA(+) is 90.47%. H.pylori (+) specimens express Fas/FasL more higher than H.poylori (-) ones ( P <0.05). The expression of Fas/FasL in gastric adenocarcinoma was higher than that in other lesions ( P <0.01). The expression of Fas/FasL in cagA(+) group did not differ significantly from that in cagA(-) group ( P > 0.05). Conclusions Our data suggest that H.pylori infection can induce the expression of Fas/FasL in gastric epithelial cells. Gastric adenocarcinoma express high amount of FasL, which may plays an important role in immune escape of stomach cancer.