Figure 4

Tumor vasculature and components of stroma in lung tumors are targeted by anti-angiogenesis. Formalin fixed paraffin embedded lung sections (5 μm) stained with anti-CD31 (endothelial cells), anti-desmin (smooth muscle cells), anti-F4-80 (macrophages), anti-VEGFR1 and anti-VEGFR2 as described in the materials and methods. The slides were scanned on Nanozoomer instrument using 20× magnification. Irrespective of treatment, AIs treated lungs showed lower CD31 and desmin density. F4-80 staining in vehicle treated mice showed greater infiltration of macrophages. However, AIs particularly axitinib and sunitinib significantly reduced macrophage infiltration in the tumors. AIs had differential effects on VEGFR1 and VEGFR2 expression since all treatments reduced VEGFR2 expression in the tumor vasculature, VEGFR1 expression was mainly inhibited by PF-210 and sunitinib. Pictures are the representative images of each staining from each treatment.