Bcl-2, Bax, Bcl-x(L) and Bcl-x(S) expression in neoplastic and normal endometrium.

The two anti-apoptotic proteins Bcl-2 and Bcl-x(L), and the two pro-apoptotic proteins Bax and Bcl-x(S) were measured by Western blotting in 51 neoplastic and 8 normal endometrial samples. The corresponding mRNA levels were analyzed by semiquantitative reverse transcriptase-polymerase chain reaction in a subgroup of 19 endometrial carcinomas. Neoplastic tissues had higher amounts of Bcl-2 protein than normal tissues (p < 0.051). Bcl-x(L) followed the same trend since its levels were higher in tumor than in normal samples (p < 0.048). Interestingly, Bcl-2 and Bcl-x(L) protein content showed a trend towards an inverse correlation (r = 0.27, p < 0.052). mRNA and protein levels directly correlated only with Bcl-2 (r = 0.63, p < 0.0032). Despite the fact that the amounts of Bcl-2, Bax and Bcl-x(L) proteins in the neoplastic population were not significantly differently distributed according to the clinicopathological features of the patients, the differences observed between normal and neoplastic samples suggest that these proteins may play a role in endometrial carcinoma: long-term follow-up studies will be required to confirm this hypothesis.