The results indicated that the PARP inhibitor GPI 15427 (IC50 on endothelial PARP: 237 ± 27 nM), at concentrations devoid of cytotoxic effects (0.5–1 μM), abrogated migration in response to vascular endothelial growth factor or placenta growth factor, hampered formation of tubule-like networks and impaired angiogenesis in vivo. The anti-angiogenic effect of the PARP inhibitor was confirmed in PARP-1 knock-out mice that displayed a defect of angiogenesis induced by growth factors.
These results provide evidence for targeting PARP for anti-angiogenesis, adding novel therapeutic implications to the use of PARP inhibitors in cancer treatment.