Fig. 1

CPT induces S phase arrest and cells death in human OS cells. a Clonogenicity of OS cells treated with various concentrations of CPT (as indicated). b Representative images of TUNEL staining in OS cells treated with various concentrations of CPT (as indicated). Bar represents 50 μm. c OS cells were treated with control and CPT (as indicated) for 24 h. Flow-cytometric analysis and quantification of distribution of cell cycle were assessed. d OS cell viability following treatment with the various concentrations of CPT for 24, 48, and 72 h. CCK-8 assay was used to assess OS cell proliferation. The results were expressed as the means ± SD from three independent experiments. *P < 0.05, significantly different compared with control