Cell-based phenotypic assays revealed the superior antileukemic activity of NTX-301. (A), Dose–response curves of five AML cell lines (MV4-11, MOLM-13, HL-60, THP-1, and KG-1) that were treated with NTX-301 or DAC for the indicated times. The p53 status of the cell lines is shown. (B–E), Flow cytometric analyses of MV4-11 cells that were treated with NTX-301 or DAC (500 nM) for 2 days to evaluate cell cycle progression by phospho-histone H3 and PI staining (B), apoptosis by Annexin V and PI staining (C), and apoptosis by cleaved Caspase 3 and PI staining (D), and those treated with NTX-301 or DAC (60 and 200 nM) for 6 days to evaluate AML differentiation by CD14 and CD11b staining (E). (F), A representative micrograph showing the morphology of MV4-11 cells that were treated with NTX-301 or DAC (60 nM).