Fig. 4.

Critical involvement of PPARδ in angiogenic process. PPARδ silencing in the tumor microenvironment inhibits tumor growth (A) and reduces tumor microvascular density (B) in LLC and B16 melanoma, two syngeneic tumors growing s.c. in WT (wt) and PPARδ (−/−) mice. A shows tumor volumes assessed 20 (LLC) and 29 (B16) days after s.c. tumor injection. Bars are mean ± SD (*, P < 0.01 in −/− vs. WT). (B) Reduced vascular density in −/− mice is demonstrated in LLC tumors (view, ×200) by CD31 (green, Alexa488, tumor vascular endothelium) and nuclear (blue, DAPI) costaining.