title: Targeting the platelet-derived growth factor receptor alpha with a neutralizing human monoclonal antibody inhibits the growth of tumor xenografts: implications as a potential therapeutic target.
abstract: Platelet-derived growth factor receptor alpha (PDGFRalpha) is a type III receptor tyrosine kinase that is expressed on a variety of tumor types. A neutralizing monoclonal antibody to human PDGFRalpha, which did not cross-react with the beta form of the receptor, was generated. The fully human antibody, termed 3G3, has a Kd of 40 pmol/L and blocks both PDGF-AA and PDGF-BB ligands from binding to PDGFRalpha. In addition to blocking ligand-induced cell mitogenesis and receptor autophosphorylation, 3G3 inhibited phosphorylation of the downstream signaling molecules Akt and mitogen-activated protein kinase. This inhibition was seen in both transfected and tumor cell lines expressing PDGFRalpha. The in vivo antitumor activity of 3G3 was tested in human glioblastoma (U118) and leiomyosarcoma (SKLMS-1) xenograft tumor models in athymic nude mice. Antibody 3G3 significantly inhibited the growth of U118 (P=0.0004) and SKLMS-1 (P <0.0001) tumors relative to control. These data suggest that 3G3 may be useful for the treatment of tumors that express PDGFRalpha.
authors.affiliation: Department of Protein Chemistry, ImClone Systems, Inc., 180 Varick Street, New York, NY 10014, USA. NickL@Imclone.com
authors.forename: Nick
authors.initials: N
authors.lastname: Loizos
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Jim
authors.initials: J
authors.lastname: Huber
authors.forename: Meilin
authors.initials: M
authors.lastname: Liu
authors.forename: Dan
authors.initials: D
authors.lastname: Lu
authors.forename: Bridget
authors.initials: B
authors.lastname: Finnerty
authors.forename: Robin
authors.initials: R
authors.lastname: Rolser
authors.forename: Asra
authors.initials: A
authors.lastname: Malikzay
authors.forename: Anita
authors.initials: A
authors.lastname: Persaud
authors.forename: Erik
authors.initials: E
authors.lastname: Corcoran
authors.forename: Dhanvanthri S
authors.initials: DS
authors.lastname: Deevi
authors.forename: Paul
authors.initials: P
authors.lastname: Balderes
authors.forename: Rajiv
authors.initials: R
authors.lastname: Bassi
authors.forename: Xenia
authors.initials: X
authors.lastname: Jimenez
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Joynes
authors.forename: Venkata R M
authors.initials: VR
authors.lastname: Mangalampalli
authors.forename: Philipp
authors.initials: P
authors.lastname: Steiner
authors.forename: James R
authors.initials: JR
authors.lastname: Tonra
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Pereira
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Zhu
authors.forename: Dale L
authors.initials: DL
authors.lastname: Ludwig
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hicklin
authors.forename: Peter
authors.initials: P
authors.lastname: Bohlen
authors.forename: Larry
authors.initials: L
authors.lastname: Witte
authors.forename: Paul
authors.initials: P
authors.lastname: Kussie
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000077214:Becaplermin; D001681:Biological Assay; D045744:Cell Line, Tumor; D004306:Dose-Response Relationship, Immunologic; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D008024:Ligands; D020935:MAP Kinase Signaling System; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D009368:Neoplasm Transplantation; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000737:chemistry; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D020574:Proto-Oncogene Proteins c-sis; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000276:immunology / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D008024:Ligands; D010982:Platelet-Derived Growth Factor; D011518:Proto-Oncogene Proteins; D020574:Proto-Oncogene Proteins c-sis; C075278:platelet-derived growth factor A; D000077214:Becaplermin; D020796:Receptor, Platelet-Derived Growth Factor alpha; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt