Fig. 5.

Nonhematopoietic ablation of EpoR increases anti-VEGF sensitivity. (A) Tumor growth rates (n = 6 animals per group). (B) Analyses of red blood cells, hemoglobin levels, and hematocrits (n = 6 animals per group). (C–E) Immunohistochemical analyses of CD31⁺ microvessels and vascular perfusion of 2,000-kDa dextran (n = 6 animals per group). Arrows in C, Upper point to CD31⁺ blood vessels and in Lower indicate perfused dextran⁺ signals (n = 10 samples per group). Quantifications of CD31⁺ vessel density and dextran blood perfusion (n = 10 samples per group). (F–K) Immunohistochemical analyses of PCNA⁺ proliferating tumor cells, Ki67⁺ proliferating tumor cells, cleaved caspase-3⁺ apoptotic tumor cells, TUNEL⁺ apoptotic tumor cells, and tumor hypoxia (n = 10 random fields per group; six animals per group). Epor (^−/−) indicates EpoR(^−/−)::HG1-EpoR mice. *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant. Data are means ± SEM. (Scale bars: 50 μm.)