Expression patterns of E-cadherin and beta-catenin according to clinicopathological characteristics of hepatocellular carcinoma

BACKGROUND/AIMS: E-cadherin is involved in intercellular binding and cellular polarity formation. beta-catenin plays a fundamental role in regulation of the E-cadherin cell adhesion complex. The abnormalities of the components of the complex may disrupt this adhesive function. We investigated the expression patterns of E-cadherin and beta-catenin to determine the clinical significance of these proteins in hepatocellular carcinoma. MATERIALS/METHODS: Thirty-six hepaticellular carcinoma tissues and adjacent non-tumor specimens were analyzed. Subcellular distribution of E-cadherin and beta-catenin was examined by immunohistochemistry staining. We evaluated the patterns of the expression, and investigated the relationship with the cause of HCC; level of AFP; TNM stage; tumor size; growth types; metastasis; differentiation grade of HCC; and presence of portal vein thrombosis. RESULTS: Immunohistochemistry showed that all non-tumor tissues had membranous type staining of E-cadherin. All non-tumor tissues showed cytoplasmic type staining of beta-catenin, but no beta-catenin accumulation in nuclei was found. 58% (21/36) of HCC showed positive expression of E-cadherin in cytoplasmic membrane. The cytoplasmic expression of beta-catenin in HCC was 83% (30/36); nuclear expression in 14% (5/36); and no staining in 3% (1/36). Nuclear beta-catenin expression was observed in none (0/4) of the well-differentiated HCC; 17%(3/9) of moderate-differentiated HCC; and 17%(2/6) of poorly-differentiated HCC. There were no relationships between E-cadherin and beta-catenin expression with other clinicopathologic factors. CONCLUSIONS: Loss of cytoplasmic staining of E-cadherin and nuclear accumulation of beta-catenin were observed in HCC. Nuclear accumulation of beta-catenin was not found in well differentiated HCC but was found in poorly differentiated HCC.