FIG. 6.

p21 induction in p53-deficient cells prevents MTI-induced endoreduplication. (A) Asynchronous cultures of HIp21 cells were treated with nocodazole (83 nM) in the presence or absence of muristerone (7.5 μM). At the indicated times, cells were harvested and processed for flow-cytometric analysis; 15,000 events were analyzed for each sample. Data are representative of three independent experiments. DNA content is represented on the x axis; the number of cells counted is represented on the y axis. The subdiploid populations have been excluded; thus, the histograms for later time points represent fewer cells. (B) Western analysis of p21 protein from HIp21 cells treated with nocodazole (83 nM) in the presence or absence of muristerone (7.5 μM). Asynchronous cells were treated for the indicated times, and protein was harvested.