Figure 1

Enhanced TH-302 cytotoxicity by Chk1 inhibitors was observed in p53-mutant HT29 cells. HT29 cells were seeded for 24 h, and then exposed to TH-302 alone, or combined with 0.1 μM of AZD7762 (A), 0.5 μM LY2603618 (B), or 0.4 μM PF477736 (C) for 2 h under either air (21% O₂) or hypoxia (N₂). After wash, cells were treated with the Chk1 inhibitors for an additional 70 h under air (21% O₂). The viable cells were detected using AlamarBlue and quantified with spectrophotometer. IC₅₀ values are presented in Table 1. Combination indexes from Chou-Talalay (CalcuSyn) analyses are presented in Table 2 (air group and N₂ group). The data are the representative of four independent experiments.