Figure 1
Os induces cell death in cancer cells via apoptosis. (a) HCT116 cells (1.25 × 105) were seeded in 24-well plates, treated with increasing doses of Os for 24 or 48 h and cell survival was assessed by crystal violet assay. Results are expressed as average of the percentage of the relative growth. HCT116 cells were treated with 50 μM of Os for 16 h, (b) cell cycle profiles were obtained by PI staining and (c) subcellular fractions were subjected to western blot analysis. (d) Os-treated cells were harvested and assayed for caspases 3, 8 and 9 activities using fluorogenic substrates, as described in Materials and Methods. Lysates from cells treated with Os (50 μM) were probed for processing of caspase 3 (e) and PARP cleavage (f). (g) Cells were preincubated with zVAD (100 μM for 1.5 h) before exposure to Os (50 μM) or staurosporine (2.5 μM) for 24 h, and survival was assessed by crystal violet staining. •P<0.05, ••P<0.025 versus control
