Expression of Urokinase-type Plasminogen Activator, a New Biologic Marker of the Invasion and Metastasis in Gastric Cancer

Mortality in gastric cancer is related to invasion and metastasis. Evidence has accumulated that invasion and rnetastasis in solid tumors require the action of tumor associated proteases, which promotes the dissolution of the surrounding tumor matrix and the basement membrane. The serine protease urokinase-type plasminogen activator(uPA), which is elevated in solid tumors, appears to play a key role in these processes. We used enzymelinked immunoabsorbent assays(ELISA) to test uPA antigen expression in tissue extracts of normal and cancer tissue of 160 gastric cancer patients. uPA level was significantly higher in cancerous tissue than normal gastric tissue(9.4 vs 5.3 ng/mg protein cytosol: p