Terminate Transducin Problems Completely

Likewise, F-14 treatment of mice transplanted with cells expressing KITD814V survived significantly longer than vehicle-treated mice (Figure?S5A; ?p?BTK inhibitor duration of F-14 treatment in KITD814V-bearing mice (6?weeks), whereas KITD814V-bearing mice treated with vehicle demonstrated a steady rise in WBC counts over time, a hallmark of MPN development and progression. At the end of 6?weeks, all mice were euthanized and analyzed. As seen in Figures 7E and 7F, vehicle-treated mice demonstrated significant enlargement of spleen compared to F-14-treated mice. Collectively, these data support the observation that targeting FAK rescues the development of FLT3ITD- and KITD814V-induced MPN in?vivo. To further investigate the role of FAK in FLT3ITD-induced MPN, we knocked down FAK expression using shRNA in cells bearing FLT3ITD and transplanted into mice as described in Figure?7A. Knockdown of FAK not only repressed the constitutive growth OTX015 of FLT3ITD-bearing cells (Figure?S5B), but more importantly, mice transplanted with cells coinfected with FLT3ITD and FAK shRNA survived significantly longer compared to mice transplanted with FLT3ITD and scrambled vector (Figure?S5C; ?p?Transducin in the FAK?/? background demonstrated reduced spleen size ( Figures 7H and 7I) and WBC counts relative to controls ( Figure?S5D). To further ascertain whether targeting FAK in the context of KITD814V-induced MPN inhibits the growth of cells that give rise to leukemia, we performed secondary transplants using BM cells derived from the primary cohorts. As seen in Figure?7J, mice transplanted with BM cells from primary donor harboring KITD814V in a FAK-deficient background (FAK?/? KITD814V) survived significantly longer than mice transplanted with BM from WT background (FAK+/+ KITD814V). The prolonged survival of these mice correlated with reduced splenomegaly ( Figures 7K and 7L). Importantly, loss of FAK in hematopoietic stem cells did not impair the engraftment or the self-renewal of these cells ( Lu et?al., 2012).