Mi503

For MI-503 (Active Biochem) treatments, leukemia cells were seeded at a density of 4 × 10⁵ cells/mL, treated with limiting dilutions of the inhibitor as indicated or 0.25% DMSO (vehicle). Cells were re-plated every 4 days to the initial density and re-treated. Viability was assessed at various time points by using the CellTiter-Glo Luminescent Cell Viability assay (Promega) following the manufacturer’s guidelines. Ratio of luminescence signal from metabolically active cells in MI-503 versus DMSO were plotted to calculate IC50 values (Prism 8, GraphPad). For MI-503 (Active Biochem) and Palbociclib HCl (Selleckchem) combination treatments, 25,000 leukemia cells in 250μL of drug-containing medium were seeded in a 48-well plate and viability was assessed every 4 days by using the CellTiter-Glo Luminescent Cell Viability assay (Promega). For RNA-Seq and ChIP-Seq experiments, cells were cultured at 4 × 10⁵ cells/mL, treated with MI-503 (concentrations as indicated in figure legends) or 0.25% DMSO for 4 days. Cells were collected, washed with PBS, pelleted, and flash-frozen before RNA or chromatin isolation. For in vivo VTP-50649 treatment, mice were randomly assigned to either normal or 0.1% VTP-50469 rodent special diet. Mice were bled weekly to monitor leukemia burden and euthanized when showing clinical signs of disease (experimental endpoint).