Abstract:Objective:To study the clinical significance of the gene protein expression of p16,nm23 and PTEN in bile duct carcinoma. Methods:The expression of p16,PTEN and nm23 gene protein in tissues of 63 cases of malignant tumors of biliary system(33 cases of bile duct carcinoma,30 cases of carcinoma of gallbladder) and 20 cases of benign bile duct lesion were studied by SP immunohistochemical technique and analyzed together with clinicopathologic data.Results:The positive expression of p16,PTEN and nm23 in bile duct carcinoma tissue was low to medium,their expression rate was 36.5%,38.1% and 23.8%,respectively,and was significantly lower than that of bile duct benign lesions(P<0.05). In the well-differentrated bile duct carcinoma and gallbladder carcinoma group,the expression of PTEN was significantly different(P<0.05),but p16,PTEN and nm23 expression was not significantly different. Conclusions:Mutation or deletion of the above 3 genes is present in malignant tumors of biliary system.PTEN and p16 gene mutation can loss control of the cell cycle and thus promote tumor development.PTEN and nm23 gene mutation can lower the controlability of invasiveness and metastasis of tumors of biliary system.