胃癌及其有关病变的幽门螺杆菌感染与抑癌基因表达的相关性研究

背景与目的:幽门螺杆菌(Helicobacterpylori,Hp)是确定的胃癌致癌因子,但其致癌的确切机制仍不清楚。p53、p21WAF1、p16为主要的细胞周期负调控基因。本研究旨在探讨胃癌及其有关病变中,上述3种抑癌基因的作用及其与幽门螺杆菌感染的关系。方法:应用HID-AB(pH2.5)-PAS、SP免疫组化染色及Warthin-Starry染色,对65例慢性萎缩性胃炎(chronicatrophicgastritis,CAG),93例肠上皮化生(intestinalmetaplasia,IM),94例胃上皮不典型增生(gastricepithelialdysplasia,GED)及60例胃癌(gastriccarcinoma,GC)中3种抑癌基因表达和幽门螺杆菌感染情况进行检测。结果:在胃癌发生的不同阶段,p53阳性表达率随病变发展而升高,在CAG、IMⅠ～Ⅱ、IMⅢ、GEDⅠ级、GEDⅡ～Ⅲ级及GC中分别为0、1.64%、6.25%、5.45%、23.08%、70.00%。p21WAF1和p16阳性表达率随病变发展而降低,p21WAF1阳性表达率分别为100%、95.08%、100%、100%、71.79%、45.00%,p16阳性表达率分别为83.08%、81.97%、78.13%、89.09%、69.23%、40.00%。三者表达在GEDⅡ～Ⅲ与GEDⅠ组间、GC与GEDⅡ～Ⅲ组间的差异均具有显著性(P<0.05)。同一病变中,Hp感染阳性组p53、p21WAF1及p16阳性表达率虽然高于Hp阴性组,但差异无显著性(P>0.05)。结论:p53突变及p21WAF1、p16失活

Relationship between Helicobacter pylori infection and expressions of tumor suppressor genes in gastric carcinoma and related lesions

BACKGROUND & OBJECTIVE: Helicobacter pylori (Hp) are believed to be a carcinogen of gastric carcinoma. However, its mechanism was yet not clearly understood. p53, p21WAF1, and p16 are main negative regulator genes of cell cycle. This study was designed to investigate the relationship between these 3 genes and Hp infection. METHODS: The authors examined the expression of these 3 tumor suppressor genes and Hp infection in 65 cases with chronic atrophic gastritis (CAG), 93 cases with intestinal metaplasia(IM), 94 cases with gastric epithelial dysplasia (GED) and 60 cases with gastric carcinoma (GC) using HID-AB (pH 2.5)-PAS, SP immunohistochemistry staining, and Warthin-Starry staining. RESULTS: For CAC, IM stage I-II, IM stage III, GED stage I, GED stage II-III, and GC, the positive expression rates of p53 were 0, 1.64%, 6.25%, 5.45%, 23.08%, and 70.00%, respectively (increased with pathological process); the positive expression rates of p21WAF1 were 100%, 95.08%, 100%, 100%, 71.79%, and 45.00%, respectively; the positive expression rates of p16 were 83.08%, 81.97%, 78.13%, 89.09%, 69.23%, and 40.00%, respectively. All the expression of these 3 genes showed significant difference between GED stage II-III and GED stage I, GC and GED stage II-III. In the same pathological changes, the positive expression rate of these 3 genes was higher in Hp infection group than in no Hp infection group, while there was no significant difference (P > 0.05). CONCLUSION: The mutation of p53 and inactivation of p21WAF1 and p16 play an important role in carcinogenesis of stomach. However, Hp infection was not associated with the abnormal expression of these 3 genes.