KT-NB arrests cells in the M phase and increases sub-G1 cell population. (A) FACS analysis of DNA content after KT-NB treatment. HeLa cells were treated with 6.75 μg/ml of KT-NB or DMSO as control. Cells were harvested for analysis after 24, 48 and 72-h treatment. Tables showed the percentage of relative cell numbers of different cell cycle phases. (B) Cells were treated with 6.75 μg/ml KT-NB for 24 h. Quantitation of the mitotic index in control and KT-NB treated cells (n > 500, three independent experiments). (C) Percentage of relative cell numbers of sub-G1 cells. Cells were calculated based on the results shown in (A).