Cytotoxicity assay, cell cycle, and annexin V analysis of HUT78 cell line treated with depsipeptide. (A) HUT78 cells were treated for 3 days with varying concentrations of depsipeptide. Cytotoxicity assay was performed using Owen reagent as described in “Materials and methods.” Data shown represent more than 3 experiments and are graphed on a linear scale. The cytotoxicity assay was performed in the absence or presence of 1 μg/mL valspodar, an inhibitor of Pgp. (B) Cell cycle analysis was performed using cells treated with or without depsipeptide (DP) at 0, 1, or 2 ng/mL for 48 and 72 hours. (C) Plot of annexin V staining of cells from the same experiment treated for 72 hours.