Fig. 1.

Depletion of spindle checkpoint blocks cell death induced by diazonamide or taxol. a Dose-dependent killing of HeLa cells by diazonamide (DA) or taxol (TX). Cells were treated with indicated concentrations of diazonamide or taxol. Cell viability was determined by measuring ATP levels using the CellTiter-Glo assay kit. In this and all the subsequent studies, cell survival was presented as the percentage of viable or dead cells compared with untreated control, and is represented as the mean ± s.d. of triplicates. b–d Effect of knockdown of spindle checkpoint protein Mad2 on diazonamide- or taxol- induced cell death. b HeLa cells were transfected with Luciferase siRNA or Mad2 siRNA for 24 h prior to incubation with 100 nM diazonamide or taxol for another 48 h. Phase-contrast images of cells are shown. Scale bars represent 100 µm. c Cell viability was determined after 48 h treatment of 100 nM diazonamide or taxol. d Mad2 knockdown efficiency was analyzed by western blotting with an anti-Mad2 antibody and normalized by Actin