Expression of cadherins and α-catenin in primary epithelial tumors of the liver

Background and Aims: Cadherins and their associated molecules, such as α- catenin, have been shown recently to play a pivotal role in epithelial carcinogenesis. Methods: The expression of E-cadherin, N-cadherin, and α- catenin in 10 normal samples, 28 focal nodular hyperplasias, 9 liver cell adenomas, 65 hepatocellular carcinomas, and 9 cholangiocarcinomas was studied by immunohistochemistry and Western blotting. Results: In the normal liver, hepatocytes expressed E-cadherin and a 129-kilodalton cadherin identified by the anti-N-cadherin antibody GC4. The expression level of α-catenin was low. Bile duct cells expressed only E-cadherin and showed high levels of α- catenin. The expression of cadherins and α-catenin was preserved in focal nodular hyperplasia. In liver cell adenomas, cadherins and α-catenin were heterogeneously expressed. In hepatocellular carcinomas, cadherin and α- catenin expression was frequently reduced or absent. Alterations in cadherin expression correlated with large tumor size, low grade of histological differentiation, and occurrence of capsular and vascular invasion. In cholangiocarcinomas, neoplastic cells inconstantly expressed E-cadherin and α-catenin. Conclusions: Alterations of cadherin and α-catenin expression are frequent in liver cell adenomas and primary liver carcinomas. Their incidence in hepatocellular carcinomas is of prognostic significance.