Resistance to apoptosis is a major obstacle preventing effective therapy for malignancies. Bcl-2 plays a significant role in inhibiting apoptosis. We reconstructed a stable human Bcl-2 transfected cell line, BIU87-Bcl-2, that was derived from the transfection of human bladder carcinoma cell line BIU87 with a plasmid vector containing recombinant Bcl-2 [pcDNA3.1(+)-Bcl-2]. A cell line transfected with the plasmid alone [pcDNA3.1(+)-neo] was also established as a control. BIU87 and BIU87-neo proved sensitive to adriamycin induced apoptosis, while BIU87-Bcl-2 was more resistant. In view of the growing evidence that NF- may play an important role in regulating apoptosis, we determined whether Bcl-2 could modulate the activity of NF- in bladder carcinoma cells. Stimulation of BIU87, BIU87-neo and BIU87-Bcl-2 with ADR resulted in an increase expression of NF- (p in BIU87-Bcl-2 was higher than in the other two cases, with a concomitant reduction in the protein level. These results suggest that the overexpression of Bcl-2 renders human bladder carcinoma cells resistant to adriamycin-induced cytotoxicity and there is a link between Bcl-2 and the NF- signaling pathway in the suppression of apoptosis.
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