Deletion of wild-type R595 in FLT3-ITD-W51 results in reduced transforming potential and STAT5 activation in Ba/F3 cells. (A) Schematic representation of wild-type R595 (FLT3-W51-ΔR595) deletion mutant in the FLT3-ITD-W51 construct. (B) Ba/F3 cells expressing the FLT3-WT, FLT3-W51-ΔR595, FLT3-ITD-W51, and mock-transduced cells were seeded at a density of 4 × 104 cells/mL in the absence or presence of IL-3. Viable cells were counted after 72 hours by trypan blue exclusion. The growth of cells with IL-3 was defined as 100% (control). The standard error of the mean calculated from 3 independent experiments is indicated. (C) Western blot image showing the activation of STAT5 in cells expressing FLT3-W51-ΔR595 and FLT3-ITD-W51, when compared to FLT3-WT or mock-transduced cells. Cells were starved in the presence of 0.3% FBS for 24 hours. Blots were incubated with anti–phospho-STAT5 antibody, stripped, and reblotted with anti-STAT5 antibody.
