VARIABLE LEVELS OF BCL-2, BCL-X AND BAX MESSENGER-RNA IN BLADDER-CANCER PROGRESSION

We investigated the expression of the anti-apoptotic genes bcl-2 and b cl-X and the pro-apoptotic gene bar in bladder tumors and normal sampl es from urinary bladder, using RT-PCR analysis. Bcl-2 mRNA was not det ected in any of the normal samples, while it was found expressed in 66 % of the low stage tumors and in 100% of the high stage tumors. Bar ex pression had an inverse progress, being present in 62% of the normal t issues examined, in 16% of the low stage tumors and in 14% of the high stage. Bcl-X gene expression was quite variable among all samples (37 % in normal tissues, 50% in the low stage tumors and 14% in the high s tage), bcl-X mRNA was only found in the isoform bcl-X-L, with anti-apo ptotic functions, whereas no sample expressed the isoform bcl-X-S, whi ch is known to suppress bcl-2 functions. Most samples expressing bcl-2 did not express bcl-X, and vice versa. These results, besides confirm ing the potential role of these genes in the pathogenesis of low stage bladder cancer strengthen the hypothesis concerning their possible in teraction in the progression of disease.