Urokinase plasminogen activator is elevated in human astrocytic gliomas relative to normal adjacent brain

We assayed urokinase plasminogen activator (uPA), tissue type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) in 43 human brain tumors (predominantly astrocytic gliomas) and in histologically disease-free brain tissue resected with 21 of the tumors. Levels of uPA, tPA, and PAI-1, measured by enzyme-linked immunosorbent assay, varied widely among individuals in neoplastic and in normal tissue but did not correlate with age or sex. Pairwise comparison of neoplastic and normal tissue from 21 individuals revealed that mean tumor uPA level was elevated 6-fold (P < 0.001). Mean tumor tPA and PAI-1 were 2.5-fold greater than those of normal brain, but these differences were not statistically significant. Tumor uPA was elevated 2- to 30-fold in 16/21 paired samples (76%). In contrast, tumor tPA was elevated 2- to 22-fold in 7/21 (33%) of pairs, whereas tumor PAI-1 was 2- to 13-fold greater in 10/21 (48%) of pairs. Our results demonstrate that elevation of uPA content is frequent in astroglial tumors, as is the case in other major human cancers.