Generation of Leukemia Mouse Models

Bone marrow cells from constitutive or inducible knockout mice (for a list of genetic mouse models used in this study see Supplementary Table 4) were harvested and cultured in Iscove’s modified Dulbecco’s medium (IMDM, Invitrogen, Carlsbad, CA) with GlutaMAX containing 20% fetal bovine serum, 50 μM 2-mercaptoethanol, 100 IU/ml penicillin, 100 μg/ml streptomycin in the presence of cytokines. For pre-B cell culture, bone marrow cells were cultured in IMDM with 10 ng/ml recombinant mouse IL-7 (Peprotech, Rocky Hill, NJ) on OP9 stroma cells. For ALL leukemia model, pre-B cells were retrovirally transduced by BCR-ABL1. ALL cells generated from inducible knockout mice were retrovirally transduced with ERT2 or Cre ERT2 virus, and puromycin selection was performed. 4-OHT was used to induce Cre mediated gene deletion. For CML-like leukemia model, the myeloid-restricted protocol described previously was used^{23 (link)}, which generates CML-like cells. Briefly, bone marrow cells were cultured in IMDM with recombinant mouse IL-3 (10 ng/ml), IL-6 (25 ng/ml), SCF (50 ng/ml, PeproTech, Rocky Hill, NJ) and then transformed by BCR-ABL1 retroviurs. Cytokines were removed after BCR-ABL1 transduction.