Treatment with CBF-β-RUNX1 inhibitor induces greater lethality in mtRUNX1 expressing AML cells than wtRUNX1 AML cells. (A) OCI-AML2, OCI-AML5, and Mono-Mac-1 cells were treated with the indicated concentrations of CBF-β-RUNX1 inhibitor AI-10-104 for 72 hours. The percent cell viability was then determined by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide assay. Columns, mean of 3 experiments; bars, standard error of the mean. *Indicates values that are significantly less than untreated cells (P < .05). ^†Indicates values significantly less in mtRUNX1 AML cells vs than wtRUNX1 AML cells (P < .05). (B) Mono-Mac-1 and OCI-AML2 cells were treated with the indicated concentrations of inactive inhibitor AI-4-88 or active AI-10-104 for 96 hours. The percentage of annexin V–positive, To-Pro-3 iodide-positive apoptotic cells were determined by using flow cytometry. Representative scatter plots are shown. (C) PD CD34⁺ wtRUNX1 AML (n = 7), and mtRUNX1 AML (n = 7) cells were treated with the indicated concentrations of AI-4-88 or AI-10-014 for 48 hours. At the end of treatment, the percentage of To-Pro-3 iodide-positive, nonviable cells were determined by using flow cytometry (*P < .01 by Kruskal-Wallis test).