Figure 2. In vitro effects of Cabozantinib on c-MET and VEGFR2 signaling.

Panel A shows a Western blot of E98NT cell extracts (20 µg per lane) treated for 30 minutes with different concentrations of cabozantinib as indicated. Protein extracts were analyzed for c-MET, phospho-c-MET, AKT, and ERK1/2, using α-tubulin as a loading control. B) MTT assays were done to determine the IC₅₀ concentration of cabozantinib on E98NT cells. Experiments were performed at least in triplicate. C) Effects of cabozantinib on cell migration. Shown are representative examples of DAPI-stained spheroids after 24 hr incubation with indicated concentrations. Number of outgrowing and migrating cells per spheroid are shown in panel D (***: p<0.001). Number of migrating cells were significantly different between groups (one-way ANOVA, p<0.0001). Post-hoc Tukey's Multiple Comparison Test revealed significant differences groups as indicated (***: p<0.001). E) Western blot of cell lysates of E98NT and HUVEC extracts, treated with 10 ng/ml VEGF with or without cabozantinib, and stained for VEGFR2, phospho-VEGFR2 and α-tubulin as an internal control. Note the absence of VEGFR2 in E98NT cells. F) Western blot of treated E98NT cell extracts with the anti-apoptotic antibody U1-70. Control sample consists of Jurkat cells treated with anisomycin.