title: Identification of a natural soluble neuropilin-1 that binds vascular endothelial growth factor: In vivo expression and antitumor activity.
abstract: Neuropilin-1 (NRP1) is a 130-kDa transmembrane receptor for semaphorins, mediators of neuronal guidance, and for vascular endothelial growth factor 165 (VEGF(165)), an angiogenesis factor. A 2.2-kb truncated NRP1 cDNA was cloned that encodes a 644-aa soluble NRP1 (sNRP1) isoform containing just the a/CUB and b/coagulation factor homology extracellular domains of NRP1. sNRP1 is secreted by cells as a 90-kDa protein that binds VEGF(165), but not VEGF(121). It inhibits (125)I-VEGF(165) binding to endothelial and tumor cells and VEGF(165)-induced tyrosine phosphorylation of KDR in endothelial cells. The 3' end of sNRP1 cDNA contains a unique, 28-bp intron-derived sequence that is absent in full-length NRP1 cDNA. Using a probe corresponding to this unique sequence, sNRP1 mRNA could be detected by in situ hybridization differentially from full-length NRP1 mRNA, for example, in cells of liver, kidney, skin, and breast. Analysis of blood vessels in situ showed that NRP1, but not sNRP1, was expressed. sNRP1 was functional in vivo. Unlike control tumors, tumors of rat prostate carcinoma cells expressing recombinant sNRP1 were characterized by extensive hemorrhage, damaged vessels, and apoptotic tumor cells. These results demonstrate the existence of a naturally occurring, soluble NRP1 that is expressed differently from intact NRP1 and that appears to be a VEGF(165) antagonist.
authors.affiliation: Departments of Surgical Research, Pathology, and Urology, Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Gagnon
authors.forename: D R
authors.initials: DR
authors.lastname: Bielenberg
authors.forename: Z
authors.initials: Z
authors.lastname: Gechtman
authors.forename: H Q
authors.initials: HQ
authors.lastname: Miao
authors.forename: S
authors.initials: S
authors.lastname: Takashima
authors.forename: S
authors.initials: S
authors.lastname: Soker
authors.forename: M
authors.initials: M
authors.lastname: Klagsbrun
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism*; D017209:Apoptosis; D015152:Blotting, Northern; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D007438:Introns; D008099:Liver / Q000378:metabolism; D008222:Lymphokines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D039942:Neuropilin-1; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology; D011485:Protein Binding / Q000187:drug effects; D020033:Protein Isoforms; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D000970:Antineoplastic Agents; D018076:DNA, Complementary; D016228:Endothelial Growth Factors; D008222:Lymphokines; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D039942:Neuropilin-1; D014443:Tyrosine