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

Objective To investigate the expression and clinical significance of urokin ase 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 c ases 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 mR NA level in high-grade gliomas was considerably higher than that in low-gra de gliomas and normal brain tissues (P < 0.01). Levels of uPA mRNA expressi on in tumor tissues with recurrence during 18 postoperative months and a su rvival period less than 3 years, were significantly higher than counterpart s (P < 0.01). uPA mRNA expression was strongly correlated with the microves sel quantity (MVQ) in gliomas ( r = 0.56, P < 0.01). uPA protein was mainly distributed in tumor cells and endothelial cells of glioblastomas and anap lastic astrocytomas. Conclusion Expression of uPA is associated with the malignant progression, invasion and angiogenesis of gliomas, and it may play a critical role in th e recurrence and prognosis of gliomas.