Rønne E, Behrendt N, Ploug M, Nielsen H J, Wöllisch E, Weidle U, Danø K, Høyer-Hansen G
Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.
J Immunol Methods. 1994 Jan 3;167(1-2):91-101. doi: 10.1016/0022-1759(94)90078-7.
Binding of the urokinase plasminogen activator (uPA) to a specific cell surface receptor (uPAR) plays a crucial role in proteolysis during tissue remodelling and cancer invasion. An immunosorbent assay for the quantitation of uPAR has now been developed. This assay is based on two monoclonal antibodies recognizing the non-ligand binding part of this receptor, and it detects both free and occupied uPAR, in contrast to ligand-binding assays used previously. In a variant of the assay, the occupied fraction of uPAR is selectively detected with a uPA antibody. To be used as a standard, a soluble variant of uPAR, suPAR, has been constructed by recombinant technique and the protein content of a purified suPAR standard preparation was determined by amino acid composition analysis. The sensitivity of the assay (0.6 ng uPAR/ml) is strong enough to measure uPAR in extracts of cultured cells and cancer tissue. Recent studies have shown that a high uPA level in tumor extracts is in some cancers associated with poor prognosis. The present assay will now allow similar prognostic studies of uPAR levels.
尿激酶型纤溶酶原激活剂（uPA）与特定细胞表面受体（uPAR）的结合在组织重塑和癌症侵袭过程中的蛋白水解中起着关键作用。现在已经开发出一种用于定量uPAR的免疫吸附测定法。该测定法基于两种识别该受体非配体结合部分的单克隆抗体，与先前使用的配体结合测定法不同，它能检测游离的和被占据的uPAR。在该测定法的一个变体中，用uPA抗体选择性地检测uPAR的被占据部分。为用作标准品，通过重组技术构建了uPAR的可溶性变体suPAR，并通过氨基酸组成分析确定了纯化的suPAR标准制剂的蛋白质含量。该测定法的灵敏度（0.6 ng uPAR/ml）足以测量培养细胞提取物和癌组织中的uPAR。最近的研究表明，肿瘤提取物中高uPA水平在某些癌症中与预后不良相关。目前的测定法现在将允许对uPAR水平进行类似的预后研究。
