Figure 4. c-Met immunoreactivity and expression in RIP-Tag2 tumors.
Ai–Aiv, confocal micrographs show the vascular pattern of c-Met immunoreactivity (red, arrows) after vehicle or after XL999 but little or no vascular staining after XL880 or XL184. Bi–iv, same images as in Ai–iv, shown here with the CD31 channel (green) added, show the colocalization of CD31 with c-Met immunoreactivity after vehicle or XL999 (arrowheads) but not after XL880 or XL184. Ci–iv, surface plots of c-Met immunofluorescence intensity show peaks that coincide with tumor vessels after vehicle or XL999, and confirm the reduction in c-Met immunofluorescence of tumor vessels after XL880 or XL184. Di, confocal micrographs show the presence of c-Met immunoreactivity (red) in some RIP-Tag2 tumor cells (green, SV40 T-antigen, arrows) and in tumor vessels (cyan, CD31) after vehicle. Dii, measurements show decrease in CD31 pixels colocalized with c-Met pixels after XL880 or XL184 but not after XL999. Diii, immunoblots show large reduction in phosphorylated c-Met after XL184 but not after XL999. Dose of XL compounds was 60 mg/kg for 7 days. * P < 0.001 vs. vehicle. † P < 0.001 vs. XL880 and XL184. Scale bar: 30 µm (A, B) and 10 µm (D).