Figure 3.

Combined inhibition of MEK and BCL-2/X_L is synergistic and induces cell death in HGSOC PDX models in vitro.

A-B, Dose-response curves of 14 HGSOC PDX ascites cells treated with ABT-263 alone (A) or in fixed ratio combination with GDC-0973 (B) for 96 h. Cell number was measured by luciferase assay and data are normalized to DMSO control. Data represents mean ± SEM of three independent experiments. Each experiment was performed with six technical replicates. C, IC₅₀ of ABT-263 alone or in combination with GDC-0973. Data are derived from the experiments in (A) and (B). Bars represent mean ± SEM of three independent experiments. D, Bliss score calculated for each of the dose combinations of GDC-093 and ABT-263 across the 14 PDX models. The dose response data of GDC-0973 alone are derived from Fig. 2A. These experiments were performed at the same time. Average of the Bliss score across the 5 doses is also reported. For Bliss score calculation details see Materials and Methods. Data are derived from experiment in (A) and (B) and Bliss score represents the mean of three independent experiments. E, Analysis of cell death induced by single agents and the ABT-263 plus GDC-0973 drug combination 96h after drug exposure (1μM of each drug). Dead cells were detected as described in Fig. 2C. Data are representative of two independent experiments and error bars are SEM (n=4 wells). DF181 was excluded from this analysis because it showed green autofluorescence that interfered with the Nuncgreen dye used to detect dead cells. F, Analysis of cell death induced by ABT-263 plus GDC-0973 drug combination (1μM of each drug) in the presence of the pan-caspase inhibitor Z-VAD-FMK as indicated. Pre-treatment with 50μM of Z-VAD-FMK was performed 24h before addition of ABT-263 plus GDC-0973. Dead cells were detected as in Fig. 2C. Data are representative of two independent experiments and error bars are SEM (n=4 wells)