Figure 8.

RAIDD and caspase-2 are required for γ-IR-induced apoptosis in p53-deficient cells. (a) Western blot analyses for the status of the indicated proteins in HCT116 p53−/− cells that were either left untransfected or transfected with the indicated siRNAs before they were γ-irradiated. Cells were analyzed 3 days after γIR. The blots shown represent results from three independent experiments. The asterisk denotes a band of unknown origin (see also figure legend Figure 7a). (b) Determination of DEVDase activities in HCT116 p53−/− cells that were treated as described in panel a. Cells were analyzed 3 days after γIR. The arbitrary units (AU) shown are the mean of three independent experiments±(S.D.)