RESUMO
Alteration of the intercellular adhesion system plays an essential role in the initiation and progression of bladder carcinomas. We followed the immunoexpression of adhesion molecules, E-cadherin, ß-catenin and Claudin-1, in relation to the histopathological grade and the pT category in a number of 50 urothelial carcinomas of the bladder, based on a final staining score (FSS), calculated on the basis of reaction intensity and labeled cells number. E-cadherin immunoexpression was identified in the membrane of tumor cells, low FSS being associated with invasive high-grade carcinomas. ß-catenin reactions were membranous in the case of low-grade noninvasive carcinomas and predominantly cytoplasmic and nuclear in the case of high-grade invasive ones, for which high FSS were associated. Claudin-1 was identified at the membrane level, the high FSS values being more frequent in the case of high-grade invasive carcinomas, although there were no significant statistical associations. Loss of E-cadherin expression and the associated positive linear relation of ß-catenin and Claudin-1 indicate the usefulness of the analyzed markers in identifying the invasive aggressive phenotype of urothelial bladder carcinomas.
Assuntos
Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Caderinas/metabolismo , Moléculas de Adesão Celular/metabolismo , Claudina-1 , Progressão da Doença , Humanos , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/patologia , beta Catenina/metabolismoRESUMO
The involvement of claudins in urothelial carcinogenesis is controversial. In this study, we analyzed Claudin-4 immunoexpression in 50 cases of bladder urothelial carcinomas depending on the main prognostic parameters of the lesions represented by the tumor grade and tumor extension. Claudin-4 immunoexpression scores were significantly higher in high-grade urothelial carcinomas and in tumors with invasion in muscularis propria. The results obtained indicate the involvement of Claudin-4 in the progression of urothelial bladder carcinomas.