Expression of E-cadherin and catenins on testis tumor.

E-cadherin (ECD) is a homophilic Ca(2+)-dependent adhesion molecule associated with cell-to-cell interactions and normal growth. Recent reports have suggested that decrease or loss of ECD facilitates tumor progression and/or metastasis. ECD functions in a complex called an adherens junction, which includes several other proteins including alpha- and beta-catenin. In the present study, fresh-frozen sections from 32 testis cancers, 16 seminomas and 16 non-seminomatous germ cell tumors (NSGCT), were examined immunohistochemically. E-cadherin was not expressed on normal germ cells, but expressed on 3 (18.8%) of 16 seminomas and 10 (62.5%) of 16 NSGCTs, mainly on the epithelial component of teratoma cells. alpha-Catenin was detected on 0 (0%) of 13 seminomas and 4 (25%) of 16 NSGCTs. beta-Catenin was detected on 10 (71.4%) of 14 seminomas and 13 (81.2%) of 16 NSGCTs. ECD was detected significantly more frequently on NSGCTs than on seminomas. Immunoblot analysis confirmed the expression of ECD and beta-catenin in NSGCTs. Expression of ECD and catenins may reflect the degree of differentiation and provide some information on the character of the tumor. Copyright 2000 S. Karger AG, Basel