CQ potentiates the effect of VPA and vorinostat in long-term experiments and colony-formation assay. (A-B) Kasumi-1 cells were treated with the indicated concentrations of (A) VPA (mM) or (B) vorinostat (Vor, μM) with or without CQ for the indicated times, and cell viability was determined by FACS analysis of PI-stained cells. (C-D) HL60 cells were treated as in A and B, and cell viability was determined by FACS analysis of PI-stained cells. (E) Kasumi-1 cells were treated with VPA (0.75 mM) or vorinostat (0.5 μM) in the absence or presence of CQ for 16 hours, 800 cells were seeded in Methocult medium in the absence of drugs, and colonies were scored 8 days later. All bars represent mean values ± SEM quantified from ≥3 independent experiments. *P < .05; **P < .01; ***P < .001.