(A and B) Evaluation of tumor vascularization

Blood vessel staining of tumor histological sections was performed with an anti-CD31 antibody. The number and area of vessels were evaluated by fluorescence microscopy. As shown, although the number of vessels is not significantly different, vessel area and size are significantly reduced in Sema4D KO mice. Error bars indicate mean ± SD. *, P < 0.0001 ( = 8 mice per group, with 10 fields per animal). Bars, 100 μm. (C) To evaluate the presence of vessel-associated pericytes, tumor sections were costained with the pericyte-specific antibodies NG2 (red) and CD31 (green). Analysis was performed on one slice per mouse ( = 8 mice per group). As shown, vessels of tumors that originated in KO mice very rarely showed a normal interaction between ECs and pericytes, and in most cases they stained negative for the presence of pericytes (right), which were instead normally present in tumors originated in control mice (left). Statistical differences between groups were determined by using the two-tailed Student's test. v.f., visual field. Bars, 50 μm.Copyright information:Taken from "Tumor angiogenesis and progression are enhanced by Sema4D produced by tumor-associated macrophages"The Journal of Experimental Medicine 2008;205(7):1673-1685.Published online 7 Jul 2008PMCID:PMC2442644.