FIG. 3.

Apoptosis induced by M protein, actinomycin D, or DRB is reduced by overexpression of Bcl-2. HeLa cells (solid squares), HeLa-empty vector cells (solid circles), and HeLa-Bcl-2 cells (open circles) were either transfected with M mRNA (A), treated with actinomycin D (B), or treated with DRB (C) for the indicated times and analyzed for caspase-3 activity and protein concentrations as described in the legend to Fig. 2. The amount of caspase-3 activated is expressed in arbitrary fluorescence units per milligram of protein. The data represent the average ± standard deviation of three experiments.