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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: Angiogenesis Inhibitors, Animals, Aorta, Capillaries, Capillary Permeability, Cell Division, Cells, Cultured, Dose-Response Relationship, Drug, Endothelial Growth Factors, Endothelium, Vascular, Humans, In Vitro Techniques, Lymphokines, Phosphorylation, Protein Binding, Rats, Receptor Protein-Tyrosine Kinases, Receptors, Growth Factor, Receptors, Vascular Endothelial Growth Factor, Tissue Extracts, Tyrosine, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factors.
user
Does the antiangiogenic agent neovastat ( AE-941 ) inhibit vascular endothelial growth factor-mediated biological effects? Context: Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis, which exerts direct effects on vascular endothelial cells, including endothelial cell proliferation and survival, tubulogenesis, and vascular permeability. In this study, we examined whether Neovastat, a naturally occurring multifunctional antiangiogenic drug, could inhibit the endothelial cell response to VEGF stimulation. We demonstrated that Neovastat was able to block the VEGF-dependent microvessel sprouting from Matrigel-embedded rat aortic rings, and it also blocked the VEGF-induced endothelial cell tubulogenesis in vitro. In vivo studies showed that Neovastat was able to specifically inhibit VEGF-induced plasma extravasation in numerous tissues, including pancreas and skin. The mechanism of action of Neovastat on VEGF-mediated effects was also evaluated at the molecular level. Neovastat was shown to compete against the binding of VEGF to its receptor in endothelial cells and significantly inhibited the VEGF-dependent tyrosine phosphorylation of VEGF receptor-2, whereas it had no significant effect on VEGF receptor-1 activity. Moreover, the inhibition of receptor phosphorylation was correlated with a marked decrease in the ability of VEGF to induce pERK activation. Neovastat does not compete against the binding of basic fibroblast growth factor, indicating a preferential inhibitory effect on the VEGF receptor.
assistant
Because Neovastat was shown previously to inhibit metalloproteinase activities, these results suggest that Neovastat is able to target multiple steps in tumor neovascularization, further emphasizing its use as a pleiotropic, multifunctional antiangiogenic drug. Final Decision: yes