Fig. 3.

Western Blots for detection of pKit, total KIT, p-PDGFRα, and p-PDGFRβ and total PDGFRβ. Upper panel: Canine UC cells were serum starved for 2 h and protein lysates were generated. Relative phosphorylation of RTKs was assessed using the Proteome Profiler Human Phospho-RTK Array Kit. Shown are representative examples of phosphoprotein arrays of canine UC cell lines. RTKs targeted by toceranib phosphate, PDGFRα, PDGFRβ, and VEGFR2 are indicated in the figure legend. Lower panel: Canine UC cells were serum starved for 2 h and protein lysates were generated. Protein was separated by SDS PAGE and western blotting for A p-KIT, total KIT, and β-actin or B p-PDGFRα/β, PDGFRβ, and β-actin was performed to validate findings of the phosphoprotein arrays. The C2 canine mastocytoma cell line (Lane 1) was used as a positive control for detection of p-KIT and total KIT