title: A mutated soluble neuropilin-2 B domain antagonizes vascular endothelial growth factor bioactivity and inhibits tumor progression.
abstract: Neuropilins (NRP1 and NRP2) are coreceptors for vascular endothelial growth factor (VEGF) and mediate angiogenesis and tumor progression. VEGF binds to the NRP1 and NRP2 B domains. Previously, it was shown that mutagenesis of the soluble NRP2 B domain (MutB-NRP2) increased affinity to VEGF by 8-fold. Here, we show that MutB-NRP2 inhibited (125)I-VEGF binding to NRP1, NRP2, and VEGFR-2. It antagonized VEGF-induced VEGFR-2/NRP2 complex formation and inhibited VEGF-induced activation of AKT, a mediator of cell survival, without affecting activation of VEGFR-2. In three-dimensional embryoid bodies, a model of VEGF-induced angiogenesis, MutB-NRP2 inhibited VEGF-induced sprouting. When overexpressed in human melanoma cells, MutB-NRP2 inhibited tumor growth compared with control tumors. Avastin (bevacizumab), a monoclonal antibody to VEGF, inhibited VEGF interactions with VEGFR-2, but not with NRPs. The combination of MutB-NRP2 and Avastin resulted in an enhanced inhibition of human melanoma tumor growth compared with MutB-NRP2 treatment only or Avastin treatment only. In conclusion, these results indicate that MutB-NRP2 is a novel antagonist of VEGF bioactivity and tumor progression.
authors.affiliation: Department of Surgery, Children's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Geretti
authors.forename: Laurens A
authors.initials: LA
authors.lastname: van Meeteren
authors.forename: Akio
authors.initials: A
authors.lastname: Shimizu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Dudley
authors.forename: Lena
authors.initials: L
authors.lastname: Claesson-Welsh
authors.forename: Michael
authors.initials: M
authors.lastname: Klagsbrun
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000068258:Bevacizumab; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D051379:Mice; D008819:Mice, Nude; D009154:Mutation / Q000235:genetics*; D039942:Neuropilin-1 / Q000378:metabolism; D039943:Neuropilin-2 / Q000502:physiology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D013552:Swine; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D039943:Neuropilin-2; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D039942:Neuropilin-1; D000068258:Bevacizumab; D040301:Vascular Endothelial Growth Factor Receptor-2