Figure 1

E2F7/8 repress tumor angiogenesis in a two-stage skin carcinogenesis model. (a) Immunohistochemical staining for Factor VIII in wildtype (WT), E2f7/8 double knockout (DKO) or E2f7/8/1 triple knockout (TKO) papillomas. Papillomas were obtained from a previously performed two-stage (application of 7,12-Dimethylbenz(a)anthracene/12-O-Tetradecanoylphorbol-13-acetate) skin carcinogenesis study.¹³ The brown staining shows factor VIII positive cells. Arrows indicate micro blood vessels (MBV) in each genetic group. (b) Quantification of MBV as depicted in (a). MBV were counted in 25, 21 and 13 fields in wildtype, DKO and TKO papillomas, respectively. Wildtype and DKO papillomas were harvested from six mice, TKO from three mice. Quantified data present the average±s.e.m. (c) qPCR analysis of Nrp1a, Vegfa, E2f1, E2f7 and E2F8 mRNA levels analyzed in wildtype (n=6) and DKO (n=9) papillomas. Quantified data present the average±s.d. compared with the indicated controls. **P<0.01; ***P<0.001; ns, not significant.