Figure 1.

Synergistic induction of cell death by β-lapachone and taxol. Colony formation was carried out as described in Materials and Methods. (A). In a typical experiment, control DU145 cells in well 1 were treated with solvent on days 1 and 2. Cells in well 2 were treated with β-lapachone at 4 μM on day 1 for 4 h, incubated in drug-free medium for 20 h, and then treated with solvent control on day 2. Taxol-alone well 3 was treated with solvent control for 4 h on day 1 and with taxol at 0.02 μM for 4 h on day 2. Cells in well 4 were treated with β-lapachone on day 1 and with taxol on day 2. In well 5, cells were treated with taxol on day 1 and with β-lapachone on day 2. In well 6, cells were treated with β-lapachone and taxol on day 2. (B) Average of results of three independent experiments.