目的探讨抑癌基因PTEN在胃癌组织中的表达水平及与其生物学行为的关系。方法应用免疫组织化学EnVision法检测116例胃癌组织,35例癌旁异型组织,56例癌旁正常黏膜组织中的PTEN蛋白表达情况。结果胃癌组织中PTEN阳性率为53.4 %(62/116),显著低于异型增生、癌旁正常黏膜组织中的阳性率71.4 %(25/35)、100 %(56/56)(P<0.001)。在各组织学类型中,高中分化腺癌PTEN蛋白阳性表达率最高(72.7 %,32/44),显著高于印戒细胞癌(29.2 %,7/24),P<0.001。PTEN蛋白的表达与淋巴结转移、侵袭程度密切相关(P<0.05)。结论PTEN基因的异常改变与胃癌的发生发展密切相关,可能是胃癌进一步恶化的标志之一,可作为胃癌生物学行为的参考指标,为胃癌的基因治疗提供参考依据。 Objective To investigate the expression of tumor suppressor gene PTEN in gastric carcinoma and its relationship with its biological behavior. Methods Immunohistochemistry EnVision method was used to detect the expression of PTEN protein in 116 cases of gastric cancer tissues, 35 cases of adjacent tissues and 56 cases of adjacent normal mucosa tissues. Results The positive rate of PTEN in gastric cancer tissues was 53.4% ​​(62/116), significantly lower than that in dysplasia tissues (71.4%, 100/56, respectively) (P <0.001) ). Among all the histological types, the positive rate of PTEN protein in high school differentiation adenocarcinoma was the highest (72.7%, 32/44), which was significantly higher than that in signet ring cell carcinoma (29.2%, 7/24), P <0.001. The expression of PTEN protein was closely related to the degree of lymph node metastasis and invasion (P <0.05). Conclusions The abnormal changes of PTEN gene are closely related to the occurrence and development of gastric cancer and may be one of the markers of further deterioration of gastric cancer. It may serve as a reference index for the biological behavior of gastric cancer and provide a reference for the gene therapy of gastric cancer.