Fig. 4.

Prolonged mitosis precedes SKI-178–induced apoptotic cell death. (A) Flow cytometry analysis of cell cycle distribution in HL-60 cells treated with SKI-178 or vehicle (DMSO) control for indicated time intervals. Histograms are representative of three separate experiments. (B) Percentage of AML cell lines in G2/M after 16 hours of treatment with SKI-178 (5 μM) or vehicle (DMSO). Error bars indicate S.D. of triplicate counts of 25,000 cells. Statistical significance was assessed by two-tailed paired student’s t test. Asterisks indicate significance: *P ≤ 0.01.