title: A fibrin antibody binding to fibronectin induces potent inhibition of angiogenesis.
abstract: Antiserum from rabbits immunised with pure human fibrinogen was affinity purified on immobilised fibrin fragment E (FFE). This FFE antibody (Ab) induced significant growth inhibition of a human cancer xenograft in mice and suppression of tumour angiogenesis, leaving no formed vessels and only CD31-staining endothelial fragments in place. Tubule formation of HUVEC on MatrigelTM was also significantly inhibited by FFE Ab. Since MatrigelTM is fibrin-free, this effect implicated a different FFE Ab binding site than FFE. Flow cytometry of HUVEC showed that FFE Ab bound to HUVEC, but with a broad range of 55-98 %. Immunofluorescent staining of HUVEC explained this range, since FFE Ab was seen not to bind to human umbilical vein endothelial cells (HUVEC) directly but instead to a matrix protein variably adherent to HUVEC. This protein was identified as fibronectin (FN) by appearance, staining with FN Ab, and by a FN knockdown study. Neither HUVEC nor matrix reacted with fibrin D-dimer (DD) Ab. Immunofluorescent stains of HUVEC matrix with FFE and FN Ab's showed that these Ab's bound to the same epitopes on FN, as also seen on Western blots of purified FN. These findings indicate the presence of an antigenic determinant in fibrinogen/FFE that is homologous with an epitope(s) in FN recognised by FFE Ab, and critical for angiogenesis in this xenograft. The FN epitope(s) remains to be identified, but the present findings can be used for the selection of the appropriate clones from mice immunised with fibrinogen which can facilitate this identification, and which may also be of clinical use.
authors.forename: Fida
authors.initials: F
authors.lastname: El-Ayoubi
authors.forename: Jean
authors.initials: J
authors.lastname: Amiral
authors.forename: Juliette
authors.initials: J
authors.lastname: Pascaud
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Charrin
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Tassel
authors.affiliation: Georges Uzan, Director of research at CNRS and INSERM U 972, Paul Brousse Hospital, 12 Ave Paul Vaillant Couturier, 94807 Villejuif, France, Tel.: +33 1 45 59 52 67, Fax: +33 1 45 59 52 68, E-mail: georges.uzan@inserm.fr.
authors.forename: Georges
authors.initials: G
authors.lastname: Uzan
authors.forename: Victor
authors.initials: V
authors.lastname: Gurewich
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000098:blood supply* / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D000939:Epitopes; D005338:Fibrin Fibrinogen Degradation Products / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D019073:HT29 Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008297:Male; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D011485:Protein Binding; D034622:RNA Interference; D013997:Time Factors; D014162:Transfection; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D000906:Antibodies; D000939:Epitopes; D005338:Fibrin Fibrinogen Degradation Products; D005353:Fibronectins; C072054:fibrin fragment E-2
keywords: FFE antibody; Fibrin fragment E (FFE); angiogenesis; fibronectin