title: Endogenous receptor-bound urokinase mediates tissue invasion of the human lung carcinoma cell lines A549 and Calu-1.
abstract: Macrophage colony-stimulating factor (CSF-1) increases the tissue invasive potential of the CSF-1 receptor-bearing lung carcinoma cell lines A549 and Calu-1 by increasing the number of endogenously bound urokinase-type plasminogen activators (u-PA)s on these cells. CSF-1, at concentrations which optimize invasion of A549 and Calu-1 cells into human amnion membranes (250 ng/ml), maximally augments the number of u-PA receptors occupied by endogenously produced urokinase. Preincubation of A549 and Calu-1 cells with the anti-u-PA monoclonal antibody MPW5UK (25 micrograms/ml) or with a 20- to 40-fold stoichiometric excess of fluid phase type 2 plasminogen activator inhibitor abrogates invasiveness, indicating that functionally active cell surface u-PA is essential for tissue invasion. In contrast, fluid phase type 1 plasminogen activator inhibitor (PAI-1, 5-15 units/ml) does not inhibit invasiveness unless preincubated with the amnion membranes. Inhibition of invasion by PAI-1 is abolished by presaturating the amnion membranes with antiitronectin monoclonal antibody (10 micrograms/ml) which prevents binding of PAI-1 to tissue-associated vitronectin. Binding of PAI-1 to tissue vitronectin is therefore a prerequisite for its inhibitory action. Thus, endogenously receptor-bound u-PA is the primary protease mediating CSF-1-induced tissue invasiveness of the lung carcinoma cell lines A549 and Calu-1.
authors.affiliation: Department of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: A
authors.initials: A
authors.lastname: Bruckner
authors.forename: A E
authors.initials: AE
authors.lastname: Filderman
authors.forename: J C
authors.initials: JC
authors.lastname: Kirchheimer
authors.forename: B R
authors.initials: BR
authors.lastname: Binder
authors.forename: H G
authors.initials: HG
authors.lastname: Remold
mesh_terms: D000650:Amnion; D000911:Antibodies, Monoclonal; D002460:Cell Line; D005109:Extracellular Matrix / Q000502:physiology; D005260:Female; D006023:Glycoproteins / Q000494:pharmacology / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms / Q000473:pathology* / Q000503:physiopathology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D015849:Plasminogen Inactivators / Q000494:pharmacology*; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000502:physiology*; D055293:Receptors, Urokinase Plasminogen Activator; D015854:Up-Regulation; D014568:Urokinase-Type Plasminogen Activator / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D019096:Vitronectin
chemical_list: D000911:Antibodies, Monoclonal; D006023:Glycoproteins; C524898:PLAUR protein, human; D015849:Plasminogen Inactivators; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D019096:Vitronectin; D016173:Macrophage Colony-Stimulating Factor; D014568:Urokinase-Type Plasminogen Activator