SU11248 inhibits FLT3-WT and FLT3-ITD phosphorylation.

(A) RS4;11 and (B) MV4;11 cells were incubated with SU11248 at the indicated concentrations for 2 hours. For RS4;11 only, cells were stimulated for 5 minutes with FL (150 ng/mL). Lysates were prepared and immunoprecipitated with an anti-FLT3 antibody. After SDS-PAGE and transfer to nitrocellulose, the blots were probed with an antiphosphotyrosine antibody (top) and subsequently stripped and reprobed with an anti-FLT3 antibody (bottom). Similar results were obtained in at least 4 independent experiments.