Figure 3

Effects of p53 and p21 inhibition on the induction of cell death and SLP in doxorubicin-treated HCT116 cells. (a) Percentages of attached HCT116 wild-type, p21−/− and p53−/− cells with apoptotic morphology (A), cells with multiple micronuclei (MN), or SA-β-gal+ cells, and the percentage of SA-β-gal+ cells in the dying (A+MN) population after 4-day exposure to 50 nM doxorubicin. The percentages of dying or SA-β-gal+ cells in untreated cell populations were ⩽2%. All the experiments were repeated with similar results. Error bars represent the Poisson standard deviation calculated as the square root of counted events and expressed as per cent abundance. (b) FACS analysis of cell division in HCT116 wild-type, p21−/− and p53−/− lines treated for 1 day with 100 nM doxorubicin and grown without drug for 6 days. Prior to drug treatment, cells were labeled with PKH2 and 10 000 cells were analysed in each sample. D: dividing cells. GA: growth-arrested cells