FIGURE 2.

AZD8055 and ABT-737 cooperate to trigger caspase activation, mitochondrial perturbations and caspase-dependent apoptosis. TE671 and RMS13 cells were treated for indicated times (A and D) or for 48 h (B and C) with 1 μm AZD8055 and/or 1 μm ABT-737 in the presence or absence of 50 μm Z-VAD-fmk. In A, caspase activation and PARP cleavage were assessed by Western blotting; arrows indicate cleavage fragments, and an asterisk indicates unspecific bands. In B, cell death was determined by PI staining and flow cytometry. In C, apoptosis was determined by analysis of DNA fragmentation of PI-stained nuclei. In D, loss of mitochondrial membrane potential (MMP) was analyzed by flow cytometry using the dye tetramethylrhodamine methyl ester. Mean + S.D. of three independent experiments performed in triplicate are shown (B–D); **, p < 0.01; ***, p < 0.001.