Figure 3

Immunohistochemical staining for COX-2 and VEGF. A, B, and C show immunohistochemical staining for COX-2 in lungs of rats injected with RCN-9. A, group 1 (control group); B and C, group 4 (JTE-522; 30 mg/kg/day). Tumor cells in all groups expressed COX-2. Degree of staining between groups 1 and 4 did not differ. Vascular structures (black arrow, B) and large airways (black arrow, C) in the rat lung were stained for COX-2. White arrow in C shows tumor cells stained for COX-2. Original magnification, A and B, ×400, C, ×200. D, E, and F show immunohistochemical staining for VEGF in lungs of rats injected with RCN-9. D and E, group 1 (control); F, group 2 (JTE-522; 3 mg/kg/day). Tumor cells of all groups expressed VEGF. Degrees of staining between groups 1 and 2 did not differ (D and F). Vascular structures (black arrow, E) and large airways (white arrow, F) were stained for VEGF in rat lung. Black arrow in F shows tumor cells stained for VEGF. Original magnification, ×400.