Macrophages form functional vascular mimicry channels in vivo.

Macrophages, key cells of the innate immune system, are known to support angiogenesis but are not believed to directly form vessel walls. Here we show that macrophages structurally form primitive, NON-ENDOTHELIAL "vessels" or vascular mimicry (VM) channels in both tumor and angiogenesis in vivo models. These channels are functionally connected to the systemic vasculature as they are perfused by intravenously injected dye.

Combination angiostatic therapy completely inhibits ocular and tumor angiogenesis.

Angiostatic therapies designed to inhibit neovascularization associated with multiple pathological conditions have only been partially successful; complete inhibition has not been achieved. We demonstrate synergistic effects of combining angiostatic molecules that target distinct aspects of the angiogenic process, resulting in the complete inhibition of neovascular growth associated with development, ischemic retinopathy, and tumor growth, with little or no effect on normal, mature tissue vasculature. Tumor vascular obliteration using combination angiostatic therapy was associated with reduced tumor mass and increased survival in a rat 9L gliosarcoma model, whereas individual monotherapies were ineffective.