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-receptor (uPAR) was characterized in six human tumor cell lines (OV-MZ-6, -10, -13, -15, -19 and OVCAR-3) established from patients with cystadenocarcinoma of the ovary. The invasive potential of the ovarian cancer cell lines determined in an in vitro invasion assay did neither correlate with the antigen level of uPA, t-PA, PAI-1 or uPAR nor with the cell surface uPA activity, however, did correlate with the cell surface-bound plasmin activity. The in vitro invasiveness of three cancer cell lines selected displaying a different pattern of uPA and uPAR expression was significantly inhibited by a recombinant soluble truncated form of the uPAR functioning as a scavenger for uPA. Our results suggest that the interference of the uPA/uPAR interaction leads to a reduced in vitro invasiveness of human ovarian cancer cells independent of the level of uPA and uPAR expression.