EXPRESSION OF THE PLASMINOGEN ACTIVATION SYSTEM IN KIDNEY CANCER CORRELATES WITH ITS AGGRESSIVE PHENOTYPE

Malignant tumors contrast with benign ones in their ability to invade adjacent tissue and to metastasize, The urokinase plasminogen activato r is a proteolytic enzyme that can facilitate these processes, In many carcinomas, the concentration of the urokinase plasminogen activator system is high. The high expression of these enzymes is related to tum or grade, In this study, we have investigated whether secretion of the urokinase plasminogen activator, urokinase plasminogen activator rece ptor, and plasminogen activator inhibitor 1 in normal kidney tissue an d kidney cancer tissue follows this pattern. We have found that urokin ase plasminogen activator, urokinase plasminogen activator receptor, a nd plasminogen activator inhibitor 1 were expressed in higher levels i n kidney cancers (squamous cell carcinoma and renal cell carcinoma) th an in normal kidney tissue and that these differences were statistical ly significant (P less than or equal to 0.05), In renal cell carcinoma s, we have observed differences between normal kidney tissue and renal cell carcinomas in males and Caucasians but not in females and Africa n Americans (P less than or equal to 0.05), Expression of the urokinas e plasminogen activator system was also higher in grade III tumors whe n compared with lower-grade tumors or normal tissue.