Abstract:Objective:To identify the expression of PTEN ,vascular endothelial growth factor(VEGF)and matrix metalloproteinase 9(MMP-9) in gastric carcinoma and its relationship to the biological behavior of gastric carcinoma. Methods:The expression of PTEN ,VEGF and MMP-9 in 71 cases of gastric carcinoma tissue and 37 cases of gastric mucosa distant from carcinoma were detected by streptavidin peroxidase immunohistochemistry. Results:The expression of PTEN in gastric carcinoma tissues(71.8%) was significantly lower than its expression in gastric mucosa distant from carcinoma(100%)(P<0.01),and expression of PTEN was inversely correlated with the histologic differentiation of the tumor,depth of tumor infiltration and lymph node metastasis(P<0.05,in all parameters),but was not related to age or sex of the patient(P>0.05).The expression of VEGF in gastric carcinoma(62.5%) was sigificantly higher than in gastric mucosa distant from carcinoma(29.7%)(P<0.01),The expression of VEGF was positively correlated with lymph node metastasis(P<0.01),but was not related to age,sex of the patient,and the degree of histological differentition or depth of tumor infiltration(P>0.05).The expression of MMP-9 in gastric carcinoma(69%) was significantly higer than in gastric mucosa distant form carcinoma(40.5%)(P<0.01) and was positively correlated with lymph node metastasis(P<0.05),but not related to age,sex of the patient,and the degree of histological differentiation or depth of tumor infiltration(P>0.05).The expression of PTEN in gastric carcinoma was inversely correlated with expression of VEGF and MMP-9(P<0.05). Conclusions:Decreased expression of PTEN was found in gastric carcinoma and significantly correlated with histologic differentiation、 depth of infiltration and lymph node metastasis of gastric carcinoma.Also,the expression of PTEN was inversely correlated with the expression of VEGF and MMP-9 in gastric carcinoma. The combined detection of PTEN,VEGF and MMP-9 may be of important clinical value toevaluate the infiltrative ability and prognosis of gastric carcinoma.