STK295900, a Dual Inhibitor of Topoisomerase 1 and 2, Induces G2 Arrest in the Absence of DNA Damage
Figure 2
STK295900 induces G2 phase arrest in HeLa cells.
(A) Flow cytometric analysis for cell cycle distribution. HeLa cells were treated with the indicated concentrations of STK295900 for 24 h. Treated cells were then stained with propidium iodide (PI) and processed for cell cycle analysis. The bar graph represents the mean percentage of each cell cycle phase ± SD from three independent experiments. * = p<0.05 versus the respective G1, S, or G2/M phase of DMSO-treated cells. (B) Mitotic index of STK295900. HeLa cells were treated with the indicated concentrations of STK295900 for 24 h. Cells were then stained with Hoechst 33342 and mitotic cells were counted. The bar graph shows mean ± SD from the representative of triplicate experiments. (C) Cell cycle related proteins expression. HeLa cells were treated with DMSO control, STK295900 (STK) 1 or 5 µM, camptothecin (CPT) 10 µM, etoposide (ETO) 10 µM, or nocodazole (NOC) 200 ng/ml for 24 h. Treated cells were lysed and subjected to immunoblot analyses with antibodies against cyclin A, cyclin B1, phospho-Histone H3 (S10), and Histone H3. β-actin was used as a loading control.