GM-CSF restores proliferation of MV 4-11 in the presence of FLT3 inhibitors.

Cells were incubated with varying concentrations of inhibitors with or without GM-CSF for 72 hours, and proliferation was assessed with an XTT-based assay. The proliferation values are expressed as a percentage of vehicle-treated controls (error bars indicate standard deviation). (A) In the absence of GM-CSF, the IC₅₀ for SU5416 and SU5614 were similar to our previous experiments (Figure 7). (B) However, in the presence of 100 ng/mL GM-CSF, no more than 60% inhibition of proliferation could be achieved even with a dose of 10 μM.