Combined Anti-PLGF and Anti-Endostatin Treatments Inhibit Ocular Hemangiomas.

BACKGROUND/AIMS The degree of neovascularization determines the aggressiveness of ocular hemangiomas (OH). So far, the anti-angiogenic treatments using either antagonists against vascular endothelial growth factor A (VEGF-A), or endostatin, do not always lead to satisfactory therapeutic outcome. METHODS We examined the VEGF receptor 1 (VEGFR1) levels in the OH specimen. We compared the effects of anti-PLGF, endostatin, as well as their combined treatments on the growth of OH in a mouse model, using bioluminescence imaging in living animals. We also examined vascularization by CD31 expression. RESULTS We detected higher VEGFR1 levels in the OH, compared to paired normal tissue. Thus, we hypothesize that as a major ligand for VEGFR1, placental growth factor (PLGF) may also play a role in the neovascularization and tumorigenesis of OH. In an implanted OH model in mice, we found that both anti-PLGF and endostatin significantly decreased OH growth as well as vascularization, while combined treatments had a significantly more pronounced effect. CONCLUSION Our data suggest that combined anti-PLGF and endostatin may be a more effective therapy for inhibition of ocular vascularization and the tumor growth in OH.