Fig. 2.
VEGFR inhibition produces greater reduction in central tumor vascularity than does anti-VEGF therapy. (A) Representative light microscopy images showing immunohistochemical detection of factor VIII (brown staining) in U87 tumors from control, bevacizumab (bev), sunitinib, and bev + sunitinib treated animals (200×) at 2, 4, and 6 weeks. (B) Bar graph demonstrating the average percentage of change in fractional area of factor VIII staining in central (c), middle (m), and peripheral (p) tumor locations in all treatment groups. *P < .05 compared with untreated controls; #P < .05 compared with sunitinib; ♦ P < .05 compared with the same treatment group at either 2 or 4 weeks. (C) Percent change in vascular density comparing the central vs peripheral tumor regions at each time point for each treatment group. *P < .05 compared with untreated controls; #P < .05 compared with sunitinib; +P < .05 compared with bev treatment. (D) Glioma cell proliferation using Ki-67 analysis at each time point. *P < .05 compared with untreated controls; #P < .05 compared with sunitinib; + P < .05 compared with the same treatment group at any of the 4.