Abstract
Inhibitors of alpha(v)beta(3) and alpha(v)beta(5) integrin have entered clinical trials as antiangiogenic agents for cancer treatment but generally have been unsuccessful. Here we present in vivo evidence that low (nanomolar) concentrations of RGD-mimetic alpha(v)beta(3) and alpha(v)beta(5) inhibitors can paradoxically stimulate tumor growth and tumor angiogenesis. We show that low concentrations of these inhibitors promote VEGF-mediated angiogenesis by altering alpha(v)beta(3) integrin and vascular endothelial growth factor receptor-2 trafficking, thereby promoting endothelial cell migration to VEGF. The proangiogenic effects of low concentrations of RGD-mimetic integrin inhibitors could compromise their efficacy as anticancer agents and have major implications for the use of RGD-mimetic compounds in humans.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Angiogenesis Inhibitors / therapeutic use*
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Animals
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Disease Models, Animal
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Humans
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Integrin alphaVbeta3 / therapeutic use*
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Lung Neoplasms / blood supply
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Lung Neoplasms / drug therapy*
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Lung Neoplasms / pathology
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Melanoma, Experimental / blood supply
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Melanoma, Experimental / drug therapy*
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Melanoma, Experimental / pathology
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Mice
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Neoplasms / blood supply
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Neoplasms / drug therapy
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Neovascularization, Pathologic / prevention & control
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Oligopeptides / pharmacology
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Oligopeptides / therapeutic use
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Receptors, Vitronectin / therapeutic use*
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Vascular Endothelial Growth Factor A / pharmacology
Substances
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Angiogenesis Inhibitors
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Integrin alphaVbeta3
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Oligopeptides
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Receptors, Vitronectin
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Vascular Endothelial Growth Factor A
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integrin alphaVbeta5
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arginyl-glycyl-aspartic acid