Changes in cadherin-catenin complexes in the progression of human bladder carcinoma

We are investigating the hypothesis that cancer progression involves the fo rmation of abnormal cadherin-catenin complexes, The detailed analysis of ca dherins and catenins expressed in a panel of 17 human bladder-cancer cell l ines revealed that E-cadherin was down-regulated at the mRNA level in 5 cel l lines. Interestingly, plakoglobin was also downregulated at the mRNA leve l in these 5 cell lines only, Furthermore, a slower migrating form of pp120 was detected in these cell lines and in 2 cell lines with heterogeneous E- cadherin expression, Cloning of the cadherins expressed in the bladder line s revealed that P-cadherin is expressed in the lines expressing E-cadherin and down-regulated at the mRNA level in lines devoid of E-cadherin. N-cadhe rin was expressed in the 5 lines with reduced E-cadherin expression, in the 2 lines with heterogeneous E-cadherin expression and in 2 other cell lines , Thus, we showed that catenin changes occur in correlation with lack of E- cadherin expression and that N-cadherin becomes predominantly expressed in cells that have lost E-cadherin expression, Our data suggest that coregulat ion of the expression of genes encoding different members of the classical cadherins occurs during tumor progression and that expression of some caten ins is also coordinated with cadherin expression. (C) 1999 Wiley-Liss, Inc.