Figure 2

Mitotic slippage after DZ treatment. a) Fragmented nuclei (arrows) in RPE-hTERT cells treated with either DMSO as a control or 10 nM of DZ for 38 hours and visualized by DAPI staining. b) Percentage of annexin-V positive cells (apoptotic cells) in untreated RPE-hTERT cells and RPE-hTERT cells treated with 10 nM of DZ, 100 nM of VBL, 1 uM of TXL for 38 hours. c) Live cell imaging of mitotic slippage. UPCI:SCC40 cells stably-transfected with GFP-H2B were pre-treated with 10 nM of DZ for 16 hours before analysis (also see the movie in Additional file 3). Arrow points to a cell that is first in mitosis and then undergoing mitotic slippage resulting in abnormally shaped nuclei. Timestamps: hours:minutes. d) Percentages of the fragmented nuclei (mitotic slippage) in cycling RPE-hTERT cells and RPE-hTERT cells arrested in the different phases of cell cycle. Serum-starvation or 4 mM hydroxyurea (HU) were used to stop cell cycling prior to the treatment with 10 nM of DZ, 100 nM of VBL, 1 μM of TXL for 38 hours. Results were averages of three independent experiments. e) Flow cytometry analysis of DNA content. RPE-hTERT cells were treated with 10 nM of DZ for 38 hours. Data are representative for three independent experiments.