EXPRESSION OF UROKINASE-TYPE PLASMINOGEN-ACTIVATOR (UPA) AND ITS RECEPTOR (UPAR) IN HUMAN OVARIAN-CANCER CELLS AND IN-VITRO INVASION CAPACITY

Expression of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (t-PA), their inhibitor PAI-1 and the uPA-recept or (uPAR) was characterized in six human tumor cell lines (OV-MZ-6, -1 0, -13, -15, -19 and OVCAR-3) established from patients with cystadeno carcinoma of the ovary. The invasive potential of the ovarian cancer c ell lines determined in an in vitro invasion assay did neither correla te with the antigen level of uPA, t-PA, PAI-1 or uPAR nor with the cel l surface uPA activity, however, did correlate with the cell surface-b ound plasmin activity. The in vitro invasiveness of three cancer cell lines selected displaying a different pattern of uPA and uPAR expressi on was significantly inhibited by a recombinant soluble truncated form of the uPAR functioning as a scavenger for uPA. Our results suggest t hat the interference of the uPA/uPAR interaction leads to a reduced in vitro invasiveness of human ovarian cancer cells independent of the l evel of uPA and uPAR expression.