Figure 5. HOXA9 expression in EOC cells promotes the ability of fibroblasts to stimulate endothelial cell growth.

(A) The average number of microvessels per 10⁴ tumor cells was calculated in tumors derived from +HOXA9 control (nontargeting) and HOXA9-knockdown (shA9-B) SKOV3ip lines by scoring 5 random fields of CD34-stained tissue sections of each mouse (n = 5 mice per group). *P < 0.005. (B) Relative mRNA levels of IL6 and VEGFA in cultured SKOV3ip cells and of IL6 and VEGFA (in human EOC cells) and Il6 and Vegfa (in mouse host cells) in omental tumors of mice that were inoculated with SKOV3ip lines (n = 5 mice per group). *P = 0.03; ^†P = 0.007. P values > 0.05 were considered not significant. Evaluation of specificity of human- and mouse- specific qRT-PCR primers is shown in Supplemental Figure 6B. (C) Growth rates of mouse endothelial cells incubated in nonconditioned medium and in SKOV3ip-conditioned media. **P < 0.005. (D) Normal omental fibroblasts were left unprimed or primed with SKOV3ip-conditioned media (shown in pink) for 5 days. Fresh nonconditioned medium was added to washed fibroblasts. Two days thereafter, medium conditioned by fibroblasts (shown in light blue) was collected. Growth rates of endothelial cells incubated in fibroblast-conditioned medium were measured. *P < 0.005. Average results of assays using 3 independent sets of each type of conditioned medium are shown in C and D.