GA101 induces nonapoptotic cell death in CD40-stimulated CLL cells. (A) Representative FACS plots of intracellular active caspase-3 staining of CD40-stimulated CLL cells incubated with GA101 for 24 hours. As a positive control, unstimulated CLL cells incubated with roscovitine are shown. Indicated are low (lo), intermediately (int), and highly (hi) caspase-3 positive cells. (B) Western blot for cleaved PARP and active caspase-3 of cell lysates from CD40-stimulated CLL cells incubated with GA101 for 24 hours. As a positive control, unstimulated CLL cells treated with roscovitine are shown. Cleaved caspase 3 (CC3; 19 and 17 kDa) and caspase-3–induced cleavage fragment of PARP-1 of 89 kDa in the presence or absence of 20μM of Q-VD are shown. Percentage cell death as assessed with MitoTracker is indicated. Results are representative of 4 experiments. (C) RXL- and GA101-induced cell death in CD40-stimulated CLL cells was not blocked by 100μM Z-VAD or 20μM Q-VD (left). Right: roscovitine-induced cell death in unstimulated CLL cells was blocked by Z-VAD or Q-VD (positive control). Data are presented as percentage specific cell death (mean ± SEM from 4 independent experiments). **.001 < P < .01 and ***P < .001 significant difference from controls (3T3).