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VEGF Inhibitors (vegf + inhibitor)
Selected AbstractsCarbohydrate-Based VEGF InhibitorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 36 2007Tobias Haag Abstract Cyclic peptide,carbohydrates (compounds 1a,c, 2, 33, 34) were designed and synthesized to act as mimetics of loop 2 of the proangiogenic molecule vascular endothelial growth factor D (VEGF-D). The mimetics were designed to inhibit dimerization of the receptors (VEGFR-2 and VEGFR-3) by VEGF-D, and thus have the potential to inhibit angiogenesis. To this end, in the previously described cyclic octapeptide CNEESLIC and the cyclic nonapeptide CGNEESLIC inhibitors derived from VEGF-D loop 2, the NEES tetrapeptide residue was replaced by a carbohydrate scaffold having the amino acid side chain mimics in positions proposed by modeling studies. Attachment of the additional amino acids using the Fmoc technology, then formation of the cyclic disulfides, and finally total deprotection afforded the target molecules of which 2 and 34 showed an ability to inhibit the biological activity of VEGF-D through VEGFR-2 in cell-based assays, albeit at high mimetic concentration.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Glioma cells under hypoxic conditions block the brain microvascular endothelial cell death induced by serum starvationJOURNAL OF NEUROCHEMISTRY, Issue 1 2005Yoshifumi Ueda Abstract Angiogenesis is one of essential components for the growth of neoplasms, including malignant gliomas. However, tumor vascularization is often poorly organized and marginally functional due to tumor strucutural abnormalities, inducing regional or temporal hypoxic conditions and nutritional shortages in tumor tissues. We investigated how during angiogenesis migrating endothelial cells survive in these hypoxic and reduced nutritional conditions. Human brain microvascular endothelial cells (HBMECs) underwent apoptosis and necrosis after serum withdrawal. This endothelial cell death was blocked by recombinant VEGF protein or the culture medium of U251 glioma cells exposed to hypoxia (H-CM). Hypoxic treatment increased vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF-,) expression in U251 glioma cells. H-CM activated nuclear factor-,B (NF,B) protein and increased the gene expression of antiapoptotic factors including Bcl-2, Bcl-XL, survivin and X-chromosome-linked inhibitor of apoptosis protein (XIAP) in endothelial cells. The survival activity of H-CM for endothelial cells was abolished by two kinds of VEGF inhibitors {Cyclopeptidic VEGF inhibitor and a VEGF receptor tyrosine kinase inhibitor (4-[(4,-chloro-2,-fluoro) phenylamino]-6, 7-dimethoxyquinazoline)} or NF,B inhibitors (ALLN and BAY 11,7082). These VEGF inhibitors did not block the activation of NF,B induced by H-CM in endothelial cells. On the contrary, TNF-, antagonist WP9QY enhanced the survival activity of H-CM for endothelial cells and blocked NF,B activation induced by H-CM under serum-starved conditions. Taken together, our data suggest that both the secretion of VEGF from glioma cells and activation of NF,B in endothelial cells induced by TNF-, are necessary for endothelial cell survival as they increase the expression of antiapoptotic genes in endothelial cells under conditions of serum starvation. These pathways may be one of the mechanisms by which angiogenesis is maintained in glioma tissues. [source] Reversible skeletal changes after treatment with bevacizumab in a child with cutaneovisceral angiomatosis with thrombocytopenia syndromePEDIATRIC BLOOD & CANCER, Issue 3 2008Angela R. Smith MD Abstract Cutaneovisceral angiomatosis with thrombocytopenia (CAT) syndrome is a rare vascular disorder of the skin and gastrointestinal tract for which there is no standard treatment. We present a case in which a child with CAT syndrome was treated with bevacizumab, a vascular endothelial growth factor inhibitor, and subsequently developed asymptomatic metaphyseal bone lesions. Though not previously described as a side effect, we hypothesize that the use of bevacizumab in a child with active epiphyseal growth plates caused these radiographic lesions. Because of the potential for altered bone growth and metabolism, children receiving VEGF inhibitors should be monitored closely for bony toxicity. Pediatr Blood Cancer 2008;51:418,420. © 2008 Wiley-Liss, Inc. [source] 3361: History of development of VEGF inhibitorsACTA OPHTHALMOLOGICA, Issue 2010E GRAGOUDAS [source] Toxicity testing of the VEGF inhibitors bevacizumab, ranibizumab and pegaptanib in rats both with and without prior retinal ganglion cell damageACTA OPHTHALMOLOGICA, Issue 5 2010Sebastian Thaler Abstract. Purpose:, To evaluate the effects of intravitreally introduced vascular endothelial growth factor (VEGF) inhibitors in rat eyes with healthy retinal ganglion cells (RGC) and into others with N-methyl-D-aspartate (NMDA)-induced RGC damage. Methods:, Bevacizumab, ranibizumab and pegaptanib were intravitreally injected each at two different concentrations. Respective vehicles of the three substances served as controls. In a different group, additionally a rat anti-VEGF antibody was injected after NMDA treatment. Retrogradely labelled RGC were counted on retinal wholemounts 1 week or 2 months after intravitreal introduction of the VEGF inhibitors. Electron microscopy (EM) was performed on normal rat eyes 2 months after introduction of the VEGF inhibitors. Results:, RGC counts in healthy rat eyes were essentially unchanged from those of the control animals after the administration of both low and high concentrations of bevacizumab, ranibizumab or pegaptanib. Compared to the other two substances, however, high doses of pegaptanib and its respective vehicle significantly decreased RGC after 1 week and led to a marked increase of mitochondrial swelling in EM. In eyes with NMDA-induced RGC damage, no changes of RGC numbers were detected after rat anti-VEGF antibody or bevacizumab, ranibizumab and pegaptanib at both tested concentrations. Conclusions:, Even at higher doses, bevacizumab and ranibizumab showed no toxic effects on RGC in vivo in either untreated rats or in the NMDA-induced RGC damage model. Also a rat anti-VEGF antibody showed no adverse effects after NMDA. Anti-VEGF therapy therefore appears safe even for eyes with additional excitotoxic RGC damage. Potential harm from the pegaptanib carrier solution at very high local concentrations cannot be excluded. [source] |