Figure 5.

CD95-indcued senescence depends on p53. (a) CRC29 colonospheres were transduced with a lentiviral vector expressing control shRNA or shRNA-targeting p53, and were subsequently exposed to FC or FC-CD95L. CD95L-induced activation of caspase-8, caspase-3, cleaved iCAD, DNA damage (γ-H2AX), and p21 induction were then assessed by western blotting. (b and c) Control CRC29 and two independent clones of p53-suppressed colonospheres were exposed to FC-CD95L for 14 days, and analyzed for SA-βGAL activity (b) and for clone-forming capacity (c). The asterisks indicate significant differences (ordinary one-way ANOVA) (****P<0.00001; **P<0.001; *P<0.01). An overview of the significance of all comparisons is provided in Supplementary Table S1