Expression and significance of urokinase-type plasminogen activator in human gliomas.

OBJECTIVE: To investigate the expression and clinical significance of urokinase type plasminogen activator (uPA) in human gliomas. METHODS: mRNA and protein expressions of uPA were examined by Northern blot hybridization and immunohistochemical method in 43 cases of gliomas and 5 cases of normal brain tissues and their relationship to clinical indexes was comprehensively analyzed. RESULTS: All tissues expressed the 2.5 kb transcript of uPA mRNA. The uPA mRNA level in high-grade gliomas was considerably higher than that in low-grade gliomas and normal brain tissues (P < 0.01). Levels of uPA mRNA expression in tumor tissues with recurrence during 18 postoperative months and a survival period less than 3 years, were significantly higher than counterparts (P < 0.01). uPA mRNA expression was strongly correlated with the microvessel quantity (MVQ) in gliomas (r = 0.56, P < 0.01). uPA protein was mainly distributed in tumor cells and endothelial cells of glioblastomas and anaplastic astrocytomas. CONCLUSION: Expression of uPA is associated with the malignant progression, invasion and angiogenesis of gliomas, and it may play a critical role in the recurrence and prognosis of gliomas.