Mohanam S, Sawaya R E, Yamamoto M, Bruner J M, Nicholson G L, Rao J S
Department of Neurosurgery, University of Texas M.D. Anderson Cancer Center, Houston, USA.
J Neurooncol. 1994;22(2):153-60. doi: 10.1007/BF01052890.
The cellular receptor for urokinase-type plasminogen activator (uPAR) in glioblastoma cell lines has been identified and found to be similar to the uPAR expressed by other tumor cell lines. Increased levels of uPAR have been found in primary malignant brain tumor tissues, especially highly malignant glioblastoma, and, to a lesser degree, in malignant astrocytomas, suggesting that this receptor might be involved in efficient activation of pro-uPA and confinement of uPA activity on the cell surface of invading brain tumors. The cell surface uPARs in gliomas could constitute an optimum environment for the generation and activity of plasmin, which is known to play a crucial role in the dissolution of the extracellular matrix during tumor cell invasion. In situ hybridization studies have shown that uPAR mRNA is expressed abundantly in tumor cells and is consistently present at the invasive edges of malignant gliomas. These results imply that uPAR is involved in plasmin-catalyzed proteolysis during glioma invasion and that interference with the uPA:uPAR interactions could constitute a novel approach for developing therapeutic strategies to counteract invasion of brain tumors.
胶质母细胞瘤细胞系中尿激酶型纤溶酶原激活剂（uPAR）的细胞受体已被鉴定出来，发现其与其他肿瘤细胞系所表达的uPAR相似。在原发性恶性脑肿瘤组织中已发现uPAR水平升高，尤其是在高度恶性的胶质母细胞瘤中，在恶性星形细胞瘤中程度较轻，这表明该受体可能参与了pro - uPA的有效激活以及uPA活性在侵袭性脑肿瘤细胞表面的限制。胶质瘤中的细胞表面uPAR可能构成纤溶酶生成和活性的最佳环境，已知纤溶酶在肿瘤细胞侵袭过程中细胞外基质的溶解中起关键作用。原位杂交研究表明，uPAR mRNA在肿瘤细胞中大量表达，并始终存在于恶性胶质瘤的侵袭边缘。这些结果意味着uPAR参与了胶质瘤侵袭过程中纤溶酶催化的蛋白水解作用，并且干扰uPA:uPAR相互作用可能构成开发对抗脑肿瘤侵袭治疗策略的新方法。
