UROKINASE PLASMINOGEN-ACTIVATOR AND UROKINASE PLASMINOGEN-ACTIVATOR RECEPTOR IN BREAST-CANCER

Urokinase plasminogen activator (uPA) is a serine protease involved in cancer invasion and metastasis. uPA mediates its action while attache d to a membrane-bound receptor (uPAR). In this investigation we show t hat uPAR levels correlate with uPA levels in human breast cancers. uPA R levels, however, do not correlate with other components of the plasm inogen activator system such as tissue-type plasminogen activator (t-P A), PAI-1 or PAI-2. In addition, uPAR revels showed no correlation wit h tumor size, axillary-node status or estrogen-receptor status. On the basis of an optimum cut-oft point, patients with breast cancers conta ining high levels of uPAR had a worse prognosis than patients with low levels of the receptor. However, as a prognostic marker in breast can cer, uPAR was not as strong as uPA, Our results are consistent with da ta from model systems suggesting that both uPA and uPAR are necessary for metastasis. (C) 1995 Wiley-Liss, Inc.