PTEN基因编码产物与胃癌发生发展相关性的研究

目的 :观察抑癌基因PTEN编码蛋白在正常胃黏膜、肠上皮化生及胃癌组织中的表达 ,探讨PTEN与胃癌发生发展的关系及作用机制。方法 :采用sABC免疫组化方法检测 184例胃癌及其癌旁肠上皮化生组织中PTEN蛋白表达 ,比较其与胃癌的WHO组织学分型、Lauren分型、临床病理分期及淋巴结转移的关系 ;另对其中 6 8例胃癌同时检测血管内皮生长因子 (VEGF)并比较它与PTEN蛋白表达的关系。结果 :胃癌组织PTEN蛋白表达显著低于正常胃黏膜 (47 8%vs 10 0 % ,P <0 0 1)。弥漫型胃癌PTEN表达显著低于肠型胃癌 (41 5 %vs 5 7 8% ,P <0 0 5 ) ;弥漫型胃癌癌旁肠上皮化生组织PTEN蛋白表达显著低于肠型胃癌旁肠化组织 (5 2 5 %vs 10 0 % ,P <0 0 1) ;进展期胃癌PTEN表达显著低于早期胃癌 (40 9%vs 6 7 6 % ,P <0 0 1) ;PTEN蛋白表达降低或失活与胃癌淋巴结转移显著正相关 (转移组4 0 3%vs非转移组 6 3 3% ,P <0 0 1) ;PTEN蛋白与VEGF表达 (31/6 8,4 5 6 %vs 5 1/6 8,75 0 % )呈一定负相关。结论 :PTEN失活或蛋白表达降低与胃癌细胞分化程度、临床病理分期及转移能力密切相关。提示PTEN基因编码产物的检测可作为判定胃癌发生及侵袭转移能力的一项客观指标

PTEN Coding Product:A Marker for Tumorigenesis and Progression of Gastric Carcinoma

Objective To detect the expression of PTEN gene product in intestinal metaplasia(IM) and neoplasm of the stomach,and investigate its clinical implication in tumorigenesis and progression of gastric carcinoma.Methods Formalin-fixed paraffin embedded tissues from 184 cases of gastric carcinoma and IM of their adjacent mucosa were evaluated for PTEN protein expression by SABC immunohistochemistry and the results were compared with clinical parameters (WHO histological classification,Lauren's classification,tumor stage,and lymph node metastasis).VEGF was also detected in 68 cases of gastric carcinoma and its correlation with PTEN was concerned.Results PTEN protein was found positive in all normal gastric mucosa.In gastric carcinoma tissues,it was negatively associated with tumor stage(40.9% in AGC vs.67.6% in EGC,P<0.01),diffuse gastric carcinoma(41.5% in diffuse type vs.57.8% in intestinal type,P<0.05),lymph node metastasis(40.3% with metastsis vs.63.3% without metastasis,P<0.01),and a negative trend of correlation toward significance was found for PTEN and VEGF (31/68,45.6% vs.51/68,75.0%).IM adjacent to diffuse gastric carcinoma showed significantly lower expression of PTEN protein than that adjacent to the intestinalgastric carcinoma (52.5% vs.100% P<0.01).Conclusion Loss or reducing expression of PTEN protein occurs commonly in gastric carcinoma and correlates with tumor stage,histologically poor differentiation and lymph node metastasis.It is suggested that PTEN can be a useful marker for predicting invasion and metastatic ability of gastric carcinoma cells.