01838nas a2200289   4500008004100000245014100041210006900182260001400251300001300265490000700278520091500285100002001200700002101220700001501241700002601256700002001282700002701302700002501329700002101354700002201375700002101397700002101418700002101439700002101460700001801481856004901499       2010                        eng d00aEffective suppression of vascular network formation by combination of antibodies blocking VEGFR ligand binding and receptor dimerization0 aEffective suppression of vascular network formation by combinati  c2010/Dec/  a630 - 400 v183 aAntibodies that block vascular endothelial growth factor (VEGF) have become an integral part of antiangiogenic tumor therapy, and antibodies targeting other VEGFs and receptors (VEGFRs) are in clinical trials. Typically receptor-blocking antibodies are targeted to the VEGFR ligand-binding site. Here we describe a monoclonal antibody that inhibits VEGFR-3 homodimer and VEGFR-3/VEGFR-2 heterodimer formation, signal transduction, as well as ligand-induced migration and sprouting of microvascular endothelial cells. Importantly, we show that combined use of antibodies blocking ligand binding and receptor dimerization improves VEGFR inhibition and results in stronger inhibition of endothelial sprouting and vascular network formation in vivo. These results suggest that receptor dimerization inhibitors could be used to enhance antiangiogenic activity of antibodies blocking ligand binding in tumor therapy.1 aTvorogov, Denis1 aAnisimov, Andrey1 aZheng, Wei1 aLeppänen, Veli-Matti1 aTammela, Tuomas1 aLaurinavicius, Simonas1 aHolnthoner, Wolfgang1 aHeloterä, Hanna1 aHolopainen, Tanja1 aJeltsch, Michael1 aKalkkinen, Nisse1 aLankinen, Hilkka1 aOjala, Päivi, M1 aAlitalo, Kari  uhttp://view.ncbi.nlm.nih.gov/pubmed/2113004302522nas a2200241   4500008004100000245008800041210006900129260001200198300001400210490000800224520178600232100002602018700002102044700002102065700002102086700002102107700002002128700002102148700002002169700002402189700001802213856004902231       2010                        eng d00aStructural determinants of growth factor binding and specificity by VEGF receptor 20 aStructural determinants of growth factor binding and specificity  c02/2010  a2425 - 300 v1073 aVascular endothelial growth factors (VEGFs) regulate blood and lymph vessel formation through activation of three receptor tyrosine kinases, VEGFR-1, -2, and -3. The extracellular domain of VEGF receptors consists of seven immunoglobulin homology domains, which, upon ligand binding, promote receptor dimerization. Dimerization initiates transmembrane signaling, which activates the intracellular tyrosine kinase domain of the receptor. VEGF-C stimulates lymphangiogenesis and contributes to pathological angiogenesis via VEGFR-3. However, proteolytically processed VEGF-C also stimulates VEGFR-2, the predominant transducer of signals required for physiological and pathological angiogenesis. Here we present the crystal structure of VEGF-C bound to the VEGFR-2 high-affinity-binding site, which consists of immunoglobulin homology domains D2 and D3. This structure reveals a symmetrical 22 complex, in which left-handed twisted receptor domains wrap around the 2-fold axis of VEGF-C. In the VEGFs, receptor specificity is determined by an N-terminal alpha helix and three peptide loops. Our structure shows that two of these loops in VEGF-C bind to VEGFR-2 subdomains D2 and D3, while one interacts primarily with D3. Additionally, the N-terminal helix of VEGF-C interacts with D2, and the groove separating the two VEGF-C monomers binds to the D2/D3 linker. VEGF-C, unlike VEGF-A, does not bind VEGFR-1. We therefore created VEGFR-1/VEGFR-2 chimeric proteins to further study receptor specificity. This biochemical analysis, together with our structural data, defined VEGFR-2 residues critical for the binding of VEGF-A and VEGF-C. Our results provide significant insights into the structural features that determine the high affinity and specificity of VEGF/VEGFR interactions.1 aLeppänen, Veli-Matti1 aProta, Andrea, E1 aJeltsch, Michael1 aAnisimov, Andrey1 aKalkkinen, Nisse1 aStrandin, Tomas1 aLankinen, Hilkka1 aGoldman, Adrian1 aBallmer-Hofer, Kurt1 aAlitalo, Kari  uhttp://view.ncbi.nlm.nih.gov/pubmed/2014511601519nas a2200193   4500008004100000245014600041210006900187260001400256300001500270490000800285520086800293100002101161700002001182700002001202700001501222700002101237700001801258856004901276       2006                        eng d00aVascular endothelial growth factor (VEGF)/VEGF-C mosaic molecules reveal specificity determinants and feature novel receptor binding patterns0 aVascular endothelial growth factor VEGFVEGFC mosaic molecules re  c2006/Apr/  a12187 - 950 v2813 aVascular endothelial growth factors (VEGFs) and their receptors play key roles in angiogenesis and lymphangiogenesis. VEGF activates VEGF receptor-1 (VEGFR-1) and VEGFR-2, whereas VEGF-C activates VEGFR-2 and VEGFR-3. We have created a library of VEGF/VEGF-C mosaic molecules that contains factors with novel receptor binding profiles, notably proteins binding to all three VEGF receptors ("super-VEGFs"). The analyzed super-VEGFs show both angiogenic and lymphangiogenic effects in vivo, although weaker than the parental molecules. The composition of the VEGFR-3 binding molecules and scanning mutagenesis revealed determinants of receptor binding and specificity. VEGFR-2 and VEGFR-3 showed striking differences in their requirements for VEGF-C binding; extracellular domain 2 of VEGFR-2 was sufficient, whereas in VEGFR-3, both domains 1 and 2 were necessary.1 aJeltsch, Michael1 aKarpanen, Terhi1 aStrandin, Tomas1 aAho, Kukka1 aLankinen, Hilkka1 aAlitalo, Kari  uhttp://view.ncbi.nlm.nih.gov/pubmed/16505489