title: Characterization of plasminogen binding to NB4 promyelocytic cells using monoclonal antibodies against receptor-induced binding sites in cell-bound plasminogen.
abstract: The NB4 promyelocytic cell line exhibits many of the characteristics of acute promyelocytic leukemia blast cells, including the translocation (15 : 17) that fuses the PML gene on chromosome 15 to the RARα gene on chromosome 17. These cells have a very high fibrinolytic capacity. In addition to a high secretion of urokinase, NB4 cells exhibit a 10-fold higher plasminogen binding capacity compared with other leukemic cell lines. When tissue-type plasminogen activator was added to acid-treated cells, plasmin generation was 20-26-fold higher than that generated by U937 cells or peripheral blood neutrophils, respectively. We found that plasminogen bound to these cells can be detected by fluorescence-activated cell sorting using an antiplasminogen monoclonal antibody that specifically reacts with this antigen when it is bound to cell surfaces. All-trans retinoid acid treatment of NB4 cells markedly decreased the binding of this monoclonal antibody. This cell line constitutes a unique model to explore plasminogen binding and activation on cell surfaces that can be modulated by all-trans retinoid acid treatment.
authors.affiliation: Cell Biology Department, Pompeu Fabra University, Barcelona, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Jardí
authors.forename: Pere
authors.initials: P
authors.lastname: Fàbregas
authors.forename: María
authors.initials: M
authors.lastname: Sagarra-Tió
authors.forename: María José
authors.initials: MJ
authors.lastname: Pérez-Lucena
authors.forename: Jordi
authors.initials: J
authors.lastname: Félez
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D001665:Binding Sites; D001752:Blast Crisis / Q000276:immunology / Q000473:pathology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism* / Q000473:pathology*; D010958:Plasminogen / Q000276:immunology* / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D055293:Receptors, Urokinase Plasminogen Activator / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D055293:Receptors, Urokinase Plasminogen Activator; D014212:Tretinoin; D010958:Plasminogen