Treatment with FHD-286 overcomes differentiation block and significantly induced CD11b expression and morphologic features of differentiation in AML cell lines with MLL1r and mtNPM1. (A-C) MV4-11, OCI-AML3, and MOLM13 cells were treated with the indicated concentrations of FHD-286 for 7 days. At the end of the treatment, cells were assessed for CD11b expression, morphologic features of differentiation, and percentage of nonviable cells. Columns, mean of 3 experiments; bars, standard error of the mean. (D) PD mtNPM1 and MLL1r AML cells were treated with the indicated concentrations of FHD-286 for 72 hours. After this, cells were stained with TO-PRO-3 iodide, and the percentage nonviable cells were determined by flow cytometry. (E-H) MV4-11, MV4-11-MITR, OCI-AML3, and OCI-AML3-MITR cells were treated with the indicated concentrations of FHD-286 for 7 days. After this, cells were assessed for the percentage expression and the mean fluorescent intensity (MFI) of CD11b by flow cytometry and morphologic features of differentiation. Data are the mean of 3 experiments; error bars indicate the standard error of the mean. ∗P < .05; ∗∗∗P < .005.