UROKINASE-TYPE PLASMINOGEN-ACTIVATOR OVEREXPRESSION ENHANCES THE INVASIVE CAPACITY OF ENDOTHELIAL-CELLS

Fetal bovine aortic endothelial GM 7373 cells were transfected with a viral expression vector harboring the human urokinase-type plasminogen activator (uPA) gene. The stable transfectant clone uPA-R5 overexpres sed and secreted human uPA as shown by Northern blot analysis, immunop recipitation of metabolically labeled proteins, plasmin chromogenic as says, and SDS-PAGE zymography of cell extracts and conditioned media. The uPA-R5 cells were analyzed for their invasive capacity in vitro in the Matrigel chemoinvasion assay in the presence of serine- or metall oprotease inhibitors. uPA overexpression enhanced the invasive capacit y of GM 7373 cells through a mechanism which differs from that mediate d by metalloproteases. Endothelial cell uPA transfectants may represen t an useful experimental model to investigate the role of uPA in angio genesis and angioproliferative diseases. (C) 1997 Academic Press.