MI-2-2 exhibits pronounced activity in MV4;11 human leukemia cells with MLL-AF4 translocation. (A) Inhibition of cell proliferation in MV4;11 cells induced by MI-2-2 after 72 hours of treatment, as detected by the MTT cell viability assay. Data represent mean values for 4 samples ± SD. The experiment was performed 3 times. (B) Apoptosis and cell death induced by MI-2-2 in MV4;11 cells as detected by flow cytometry using Annexin V/propidium iodide (PI) staining. Data represent mean values for duplicates ± SD. (C) Histograms from cell-cycle analysis performed by FACS after PI staining in MV4;11 cells treated with DMSO and MI-2-2. (D) Dose-dependent effect of MI-2-2 on cell-cycle progression measured by FACS in MV4;11 cells after PI staining. Data represent the mean values for 4 experiments ± SD. (E) Expression of the HOXA9 and MEIS1 genes normalized to 18S rRNA determined by quantitative RT-PCR in MV4;11 cells treated for 4 days with MI-2-2 referenced to DMSO-treated cells. Data represent the mean values for duplicates ± SD. (F) Quantification of CD11b expression in MV4;11cells treated for 7 days with the MI-2-2 as detected by flow cytometry. Data represent the mean values for duplicates ± SD. The experiment was performed 2 times. (G) Wright-Giemsa–stained cytospins demonstrating differentiation of MV4; 11 cells after 10 days of treatment with MI-2-2 and compared with DMSO. (H). Comparison of growth curves for MV4;11 cells treated with DMSO, MI-2, and MI-2-2.