幽门螺杆菌cagA基因株与胃癌p53,bcl—2表达的研究

目的　通过研究幽门螺杆菌（Ｈｐ）及细胞毒蛋白相关基因Ａ 株〔ｃａｇＡ（＋ ）株〕感染与胃癌组织ｐ５３、ｂｃｌ２ 表达的相互关系，以探讨Ｈｐ 的可能致癌机制。　方法　聚合酶链反应（ＰＣＲ）检测９２ 例胃癌和２４ 例浅表胃炎组织石蜡标本Ｈｐ 和ｃａｇＡ（＋ ）株感染。用免疫组化方法检测全部标本的ｐ５３、ｂｃｌ２ 表达。　结果　（１）Ｈｐ 感染在胃癌和浅表胃炎病例间差异无显著性（７９４％ 及６６７％ ，Ｐ＞ ００５），而ｃａｇＡ（＋ ）株感染前者高于后者（９３２％ 及５００％ ，Ｐ＜ ００１）；（２）ｐ５３、ｂｃｌ２ 的表达在Ｈｐ（＋ ）与Ｈｐ（－ ）组之间差异无显著性，而ｃａｇＡ（＋ ）株感染组均显著高于ｃａｇＡ（－ ）株组（Ｐ＜００１）。　结论　胃癌的发生可能与不同Ｈｐ 菌株感染有关。产生细胞毒素的Ｈｐ 菌株〔ｃａｇＡ（＋ ）株〕与胃癌关系更密切，它可能是导致ｐ５３ 基因突变和ｂｃｌ２基因过度表达的原因之一。

A study on helicobacter pylori strains possessing cagA gene and expressions of p53, bcl 2 in gastric carcinoma

Objective To study the relationship between helicobacter pylori(Hp) infection and expressions of p53, bcl 2 in gastric carcinoma (GC). Methods PCR assay was used for the detection of Hp and cagA positive strains in GC(n=92) and chronic superficical gastritis (CSG, n=24). Expressions of bcl 2, p53 were detected by immunohistochemical staining in all the cases. Results (1)There were no difference between the cases of GC and CSG about Hp infection (79 4% vs 66 7%, P >0 05), however, it was higher in cagA positive cases of GC than in CSG (93 2% vs 50 0%, P <0 01). (2)There were no significant difference between Hp positive cases and negative ones about abnomal expressions of bcl 2, p53, however,they were higher in cagA positive cases than in cagA negative ones( P <0 01). Conclusions Infection with Hp strains possessing cagA gene had a close relationship with the GC, particularly the intestinal type GC, it might contribute to the pathogenesis of gastric carcinoma through p53 gene mutation and abnomal expression of bcl 2.