Expression and significance of urokinase type plasminogen activator gene in human brain gliomas

Background and Objectives: Urokinase type plasminogen activator (uPA) regul ates a variety of processes involved in tissue morphogenesis, cell differen tiation, migration and invasion. We analyzed the available informations to better interpret the pathogenetic relationship between uPA activity and the malignant biological behavior of human brain gliomas. Methods: We retrospectively studied the presence and distribution of uPA in human brain gliomas by Northern blot hybridization and immunohistochemical methods in 43 cases of brain gliomas and 5 cases of normal brain tissues. Results: All tissues expressed 2.5 kb transcripts of uPA mRNA. The uPA mRNA levels were significantly higher in high-grade gliomas than in low-grade g liomas and normal brain tissues (P < 0.01). Levels of uPA mRNA expression i n tumor tissues with recurrence in 18 months postoperatively and survival p eriod less than 3 years were significantly higher than counterparts (P < 0. 01). The distribution of uPA protein in the immunoreactivity was mainly in tumor cells and microvascular endothelial cells of glioblastomas and anapla stic astrocytomas, localizing at, cytoplasms, especially near sites of vasc ular proliferation and at the leading edges of tumors. Conclusions: High expression of uPA gene is associated with the malignant p rogression of gliomas and demonstrates a high level of correlation with the recurrence and invasive behaviors of high grade gliomas. J. Surg. Oncol. 2 000:74:90-94. (C) 2000 Wiley-Liss, Inc.