EXPRESSION OF E-CADHERIN AND ALPHA-CATENIN, BETA-CATENIN AND GAMMA-CATENIN IN HUMAN BLADDER CARCINOMAS - ARE THEY GOOD PROGNOSTIC FACTORS

E-cadherin, the epithelium-specific cadherin, is known to play a major role in tumor progression in many human carcinomas, via intercellular hemophilic Ca2+-dependent adhesion. This adhesion is mediated by a gr oup of cytoplasmic proteins, including the alpha-, beta- and gamma-cat enins that link the E-cadherin to the actin cytoskeleton. Recent studi es have shown that loss or reduction of either E-cadherin or catenin e xpression was strictly related to clinicopathological data in bladder tumors, and E-cadherin might constitute prognostic factors in bladder carcinogenesis. Here we continued a preliminary work on E-cadherin in bladder cancer. In an effort to evaluate their possible prognostic val ue, we investigated both E-cadherin and catenins in 99 bladder tumors by immunohistochemistry. E-cadherin and all the catenins were strongly expressed in normal urothelium. Regarding histopathological data, the tumors examined showed that the disrupted expression of each molecule , except for gamma-catenin, was directly related to increasing tumor g rade (mainly for alpha- and beta-catenin) and deep invasion (p less th an or equal to 0.01), The aberrant expression of E-cadherin and beta-c atenin was also correlated to the presence of distant metastasis (p < 0.05). However, only abnormal expression of alpha-catenin was associat ed with poor survival (p = 0.037). Therefore our results suggest that alpha-catenin is directly involved in tumor invasion and dedifferentia tion and is the only protein of any prognostic value, albeit low in pa tients with bladder cancer.