MLL-AF9 AML mouse model

The model was established as described previously.12^,15 For the generation of primary MLL-AF9–driven AML, granulocyte-monocyte progenitors (GMPs) were sorted from lineage-depleted BM cell suspensions obtained from wild-type (WT), CD45.1 C57Bl/6, or mTmG donor mice using a FACS Aria II (BD Biosciences). GMPs were then transduced with retrovirus expressing the MLL-AF9 oncogene followed by IRES-GFP/dsRed; the transduction efficiency was determined by flow cytometry (using a FACS Canto II, BD Biosciences). pMIR/pMIG-FLAG-MLL-AF9 were a gift from Daisuke Nakada (Addgene plasmids #71444 and 71443). A total of 100-200 k transduced GMPs were injected intravenously into sublethally irradiated (450 rads) WT C57Bl/6 recipient mice and primary AML blasts were harvested from these animals upon full disease infiltration (about 3 months posttransplantation). A total of 100 000 leukemic cells were injected into nonirradiated secondary and tertiary recipients.