(A) Cells were cultured in serum-free medium for 16 hours and washed once with PBS once before stimulation with FL (100 ng/mL for 15 minutes). Total cellular protein extracts derived from 1 × 107 cells were immunoprecipitated with anti-FLT3 antibody. The immunoprecipitates were resolved by 8% SDS-PAGE and subjected to immunoblot analysis with antiphosphotyrosine antibody 4G10. The same blot was stripped and reprobed with anti-FLT3 antibody. Total protein lysates (50 μg) were resolved by 10% SDS-PAGE and subjected to immunoblot analysis with anti-phosphoSTAT5, anti-phosphoAKT, and anti-phosphoMAPK antibody. The same blot was stripped and reprobed with anti-STAT5, anti-AKT, anti-MAPK, and anti-HSP90 antibodies.
(B) Cells were cultured in serum free medium for 4 days in the presence and absence of FL (100 ng/mL). The survival of the cells was assessed by MTT assay. The result shown here is representative of three independent experiments (Bars represent standard deviation in the figure).