EXPRESSION OF 3 CELL-ADHESION MOLECULES IN BLADDER CARCINOMAS - CORRELATION WITH PATHOLOGICAL FEATURES

Recently, independent studies have shown that the expression of two in tegrin chains, beta 4 and alpha 2, plus the epithelial cadherin are re lated to tumour progression in human bladder carcinomas. For the first time, we compare the expression of these three cell adhesion molecule s using immunohistochemical analysis of consecutive cryosections from a series of 50 bladder tumours. E-cadherin, beta 4, and alpha 2 were s trongly expressed in normal urothelium. A majority of non-invasive bla dder cancers stained positively for E-cadherin (62%), whereas only 29% expressed normal positivity for alpha 2, and only 35% for beta 4. How ever, most invasive tumours presented an aberrant expression of alpha 2 (81%), beta 4 (100%), and E-cadherin (75%). We studied the correlati on of immunoreactivity with histological grade and stage. The alpha 2 pattern was not correlated with stage and grade. In contrast, loss of normal beta 4 expression was significantly related to increasing tumou r grade and deep invasion with a higher correlation for grade. Finally , E-cadherin expression was highly correlated with stage, but not with grade. Thus our results indicate that, although many invasive bladder rumours presented a disorder in expression of the two integrins alpha 2 and beta 4, E-cadherin appeared to be a better marker of invasivene ss in bladder carcinomas.