TNP-470 and recombinant human interferon-alpha 2a inhibit angiogenesis synergistically

The hypothesis that the combination of two known antiangiogenic agents TNP- 470 and interferon (IFN)-alpha exerts synergistic effects has been investig ated in vitro and in vivo. In vitro, TNP-470 and recombinant human IFN-alph a 2a (rhIFN-alpha 2a) resulted in a dose-dependent inhibition of proliferat ion of human umbilical vein endothelial cells (HUVECs) and EA.hy926 endothe lial cells. Compared with the two agents used singly at their lowest or ine ffective doses, combined treatment with the same doses inhibited more inten sely in the absence of cytotoxicity and displayed similar behaviour on cell chemotaxis and capillary morphogenesis on Matrigel. However, the secretion of matrix metalloproteinase 2 (MMP-2) and MMP-9 was not influenced by the two agents, either alone or in combination, even when they were applied at their lowest efficacious doses or at higher cytotoxic doses. Experiments in vivo with the chick embryo chorioallantoic membrane (CAM)-sponge assay rev ealed the same dose-dependent inhibition and synergy. As the basic fibrobla st growth factor (bFGF)-induced angiogenesis in the CAM-sponge model was st rongly inhibited by the combined treatment, TNP-470 and rhIFN-alpha 2a woul d appear to exert antiangiogenesis synergistically, perhaps by interfering with the bFGF-mediated pathway.