Objective:To study the expression of E-cadherin,N-cadherin,TGF-|3 1 and Twist protein and investigate its significance in the occurrence and development of prostate cancer.Methods:The expression of E-cadherin,N-cadherin,TGF-β1 and Twist protein in 59 prostate cancer tissues and 21 adjacent tissues were detected by immunohistochemical SABC staining,and the correlation with clinicopathological features was analyzed.Results:Positive rates of E-cadherin,N-cadherin,TGF-β1 and Twist were 32.2%,54.2%,71.2%and 74.6%,respectively,in prostate cancer tissues and 85.7%,9.52%,19.0%and 9.52%,respectively,in cancer—adjacent tissues,with significant differences between the two groups(P<0.05).The reduced expression of E-cadherin was related to the differentiation of prostate cancer tissues and PSA level,but was not associated with clinical stage,lymph node metastasis,bony metastasis and age.The increased expression of N-cadherin,TGF-β1 and Twist was related to the differentiation of prostate cancer tissues,clinical stage,lymph node metastasis,bony metastasis,but not to age.The difference in positive expression of N-cadherin and TGF-β1 was significant between PSA≤20μg/L group and PSA>20μg/L group,but the positive expression of Twist was not significant between groups.The expression of E-cadherin was highly negatively correlated with that of N-cadherin and also highly negatively correlated with that of Twist The expression of TGF-β1 was correlated with those of E-cadherin,N-cadherin and Twist.Conclusions:The reduced expression of E-cadherin,abnormal expression of N-cadherin,transformation form E-cadherin to N-cadherin and the increased expression of TGF-β1 and Twist play an important role in the occurrence and development of prostate cancer. Objective: To study the expression of E-cadherin, N-cadherin, TGF- | 3 1 and Twist protein and investigate its significance in the occurrence and development of prostate cancer. Methods: The expression of E-cadherin, N-cadherin, TGF -β1 and Twist protein in 59 prostate cancer tissues and 21 adjacent tissues were detected by immunohistochemical SABC staining, and the correlation with clinicopathological features were analyzed. Results: Positive rates of E-cadherin, N-cadherin, TGF-β1 and Twist were 32.2 %, 54.2%, 71.2% and 74.6% respectively, in prostate cancer tissues and 85.7%, 9.52%, 19.0% and 9.52%, respectively, in cancer- adjacent tissues with significant differences between the two groups (P < . The reduced expression of E-cadherin was related to the differentiation of prostate cancer tissues and PSA level, but was not associated with clinical stage, lymph node metastasis, bony metastasis and age. And the increased expression of N-cadherin, TGF-β1 and Twist was related to the differentiation of prostate cance r tissues, clinical stage, lymph node metastasis, bony metastasis, but not to age. difference between positive expression of N-cadherin and TGF-β1 was significantly between PSA≤20 μg / L group and PSA> 20 μg / L group, the the positive expression of Twist was not significant between groups. The expression of E-cadherin was highly negative correlated with that of N-cadherin and also highly negatively correlated with that of Twist The expression of TGF-β1 was correlated with those of E-cadherin, N-cadherin and Twist. Conclusions: The reduced expression of E-cadherin, abnormal expression of N-cadherin, transformation form E-cadherin to N-cadherin and the increased expression of TGF-β1 and Twist play an important role in the occurrence and development of prostate cancer.