Figure 4

Cyclin B degradation is correlated with mitotic slippage. RPE-hTERT cells were treated with 10 nM of DZ in the following experiments. a) Immunoblot analysis of cyclin B during a time course from 4 to 48 hours. Actin was a loading control. b) Percentages of fragmented nuclei analyzed at the same time points as in a. c) Upper panel: a schematic experimental design. Cells were treated with DZ for 47 hours. 5 μM MG132 was added 23 hours after DZ was added to avoid a lethal toxicity effect on the cells. Lower panels: cyclin B protein levels and percentages of fragmented nuclei analyzed as in above experiments. Data are representative for three independent experiments.