多药耐药基因产物及p53、Bcl-2蛋白在胃癌组织中的表达

Expression of multidrug resistant gene products and p53and Bcl-2 proteins in gastric carcinoma

目的 探讨多药耐药基因产物P -糖蛋白(P - gp)、谷胱甘肽 -S-转移酶π(GSTπ)及DNA拓扑异构酶Ⅱ(TopoⅡ)、p53、Bcl-2蛋白在胃癌发生、发展和耐药性产生中的作用以及相互间的关系。 方法 应用免疫组化SP法检测胃癌组织中P - gp、GSTπ及TopoⅡ与 p53、Bcl-2蛋白的表达情况。结果 胃癌组织中P - gp在淋巴结转移组和癌组织浸润达浆膜外组的阳性表达率显著高于无淋巴结转移组和浆膜内浸润组的阳性表达率(P<0.05) ;GSTπ及p53蛋白在淋巴结转移组的阳性表达率显著高于无淋巴结转移组的阳性表达率(P<0.05) ;Bcl-2蛋白的阳性表达率为50.0% ,高分化腺癌的阳性表达率显著高于未分化癌的阳性表达率(P<0.05)。胃癌组织中P- gp与 p53、Bcl-2蛋白的表达有正相关性 (r>0.3)。 结论 p53、Bcl-2蛋白参与了胃癌的发生 ;P - gp阳性表达提示胃癌细胞对化疗药物存在原发性耐药 ,同时与癌细胞浸润深度、淋巴结转移有关。有多种耐药机制参与了胃癌耐药性的发生。

Objective To detect P-gp,GSTπ,TopoⅡand p53,Bcl-2proteins in gastric carcinoma and to discuss their relation to carcinogenesis,tumor progression and drug resistant of gastric cancer.Methods The expressions of P-gp,GSTπ,TopoⅡand p53,Bcl-2protein were examined with SP immunohistochemical technique in70cases of gastric carcinoma.Results In patients with lymph node metastasis,the positive rates of P-gp,GSTπand p53were significantly higher than those in patients without lymph node metastasis(P<0.05),the positive rate of P-gp in the carcinomas with serous membrane infiltration was significantly higher than those in the carcinomas without serous membrane infiltration(P<0.05).The overall expression rate of Bcl-2protein in gastric carcinoma was50.0%(35/70),however,that in well differentiated adenocarcinomas was significantly higher than that in undifferentiated carcinoma(P<0.05).There was a significant relationship between the ex-pressions of P-gp and p53,P-gp and Bcl-2(r>0.3).Conclusion The mechanism of drug resistance in gastric carcinomas is various;the expressions of P-gp may represent the primary drug resistance in gastric car-cinoma.