Characterization of Murine and Human Cell Lines

All cells were maintained in RPMI 1640 culture medium supplemented with 10% fetal calf serum. Murine cell lines were derived in-house [4 (link), 6 (link), 14 (link)] and constantly monitored for the expression of their definitive chimeric kinases. Human KG1 cells were obtained from ATCC and similarly charcterized for the expression of the FGFR1OP2-FGFR1 fusion kinase. Cell proliferation was assessed using Trypan blue exclusion assays over a time course and cell viability was measured using the CellTitre Glow assay according to the manufacturer’s instructions (Promega). Western blot, genomic DNA preparation, plasmid transfection, quantitative RT-PCR, miR146b overexpression, cell cycle and cell apoptosis assays followed standard procedures that have been described extensively previously [9 (link), 15 (link)]. Antibodies used for western blotting (dilution 1:1000): β-Actin (Cell signaling, #5125), IRAK1 (Cell signaling, # 4504), p-IRAK1 (Sigma-Aldrich, SAB4504246), IFN-γ (Abclonal, # A12450), CXCL9 (Abclonal, # A19135), p-AKT (Cell Signaling, # 9272), AKT (Cell Signaling, # 9271), p- p38α (Cell Signaling, # 9211), p38α (Cell Signaling, # 9218), p-Stat3 (Cell Signaling, # 9134), Stat3 (Cell Signaling, # 4904).