Reduced expression of E-cadherin/catenin complex in hepatocellular carcinomas

To examine the immunoreactivity of E-cadherin and four subtypes of catenin family in human hepatocellular carcinomas (HCCs) and to investigate the correlation between expression of E-cadherin/catenin complex and clinicopathologic parameters of HCC patients.

An immunohistochemical study for E-cadherin and catenins was performed on 97 formalin-fixed, paraffin-embedded specimens of HCC.

Reduced expression of E-cadherin, alpha-, beta-, gamma-catenin and p120 was observed in 69%, 76%, 63%, 71% and 73%, respectively. Both expressions of E-cadherin and catenin components were significantly correlated with tumor grade (P = 0.000). It showed significant difference between expression of catenin members and tumor stage (P = 0.003, P = 0.017, P = 0.007 and P = 0.000, respectively). The reduced expression of E-cadherin in HCCs was significantly correlated with intrahepatic metastasis (IM) and capsular invasion (P = 0.008, P = 0.03, respectively). A close correlation was also observed between the expression of catenins and the tumor size (P = 0.002, P = 0.034, P = 0.016 and P = 0.000, respectively). In addition, the expression of each catenin was found correlated with IM (P = 0.012, P = 0.049, P = 0.026 and P = 0.014, respectively). No statistically significant difference was observed between the expression level of E-cadherin/catenin complex and lymph node permission, vascular invasion and satellite nodules. Interestingly, only expression of p120 showed correlation with AFP value (P = 0.035). The expression of E-cadherin was consistent with alpha-, beta-, gamma-catenin and p120 expression (P = 0.000). Finally, the abnormal expression of E-cadherin/catenin complex was significantly associated with patients' survival (P = 0.0253, P = 0.0052, P = 0.003, P = 0.0105 and P = 0.0016, respectively). Nevertheless, no component of E-cadherin/catenin complex was the independent prognostic factor of HCC patients.

Down-regulated expressions of E-cadherin, catenins and p120 occur frequently in HCCs and contribute to the progression and development of tumor. It may be more exact and valuable to detect the co-expression of E-cadherin/catenin complex than to explore one of them in predicting tumor invasion, metastasis and patient's survival.