Anticancer activity of a novel small molecule tubulin inhibitor STK899704
Fig 2
Antimitotic effect of STK899704.
(A) Flow cytometric analysis for cell cycle distribution. HeLa cells were treated with the indicated concentrations of STK899704 for 24 h. Treated cells were then stained with propidium iodide (PI) and processed for cell cycle analysis. Data are representative of three independent experiments. (B) Mitotic index. HeLa cells were treated with the indicated concentrations of STK899704 for 17 h. Cells were then stained with Hoechst 33342 and mitotic cells were counted. At least 100 cells were counted from the different regions. (C) Cell cycle related protein expression. HeLa cells were treated with DMSO control, 200 ng/ml nocodazole (Noc), or indicated concentrations of STK899704 for 17 h. Treated cells were lysed and subjected to immunoblot analysis with antibodies against cyclinB1, Plk1, Cdc25C, histone H3, and phospho-histone H3 (S10). β-actin was used as a loading control. (D) Reversible effect of STK899704. HeLa cells were treated with nocodazole (200 ng/ml) or STK899704 (1 or 5 μM) for 17 h. Cells were washed twice and released into fresh DMEM without nocodazole or STK899704. Cells were then stained with PI at the indicated time and processed for cell cycle analysis. Each Bar indicates mean ± SD from three independent experiments.