Fig. 7.

Overexpression of Bcl-2 inhibits both caspase-3 activation and apoptosis induction by H₂O₂ or C₆-ceramide. A: A549 cells stably transfected either with an empty vector or with vector containing human Bcl-2 cDNA were lysed and analyzed by SDS-PAGE and Western immunoblotting using anti-Bcl-2 antibody. B and C: cells transfected with empty vector and Bcl-2 overexpressing A549 cells were treated with 150 µM H₂O₂ or 50 µM C₆-ceramide. Caspase-3 activity (B) was determined by FIENA after 12 h, whereas apoptosis (C) was detected by flow cytometry after 24 h. D: cells transfected with empty vector (○) and Bcl-2 overexpressing (●) A549 cells were treated with 50–400 µM H₂O₂ and apoptosis was measured (by flow cytometry) after 24 h. Values are presented as the percent (%) of control untreated cells.