膀胱癌细胞尿激酶受体的放射配基结合分析

Radio-ligand binding assay of urokinase receptor on cellular membrane of bladder cancer

目的 :研究膀胱移行细胞癌细胞膜尿激酶受体 (uPAR)与尿激酶 (uPA)的结合特性及其与膀胱移行细胞癌生物学行为之间的关系。方法 :采用放射配基结合受体分析方法对 18例膀胱移行细胞癌组织及 6例正常膀胱粘膜uPAR的表达及与uPA的亲和力进行检测。结果 :膀胱癌组织uPAR最大结合容量Bmax为 ( 4 2 0 8± 84 6)pmol/ g蛋白 ,平衡解离常数Kd值为 ( 1 2 3± 0 5 )nmol/L ,正常膀胱黏膜Bmax为 ( 84 5± 10 4)pmol/ g蛋白 ,Kd值为 ( 5 5 0± 1 48)nmol/L ,二者比较差异具有统计学意义 ,P <0 0 1。随着膀胱肿瘤分级、分期的增高和转移的出现 ,uPAR结合位点数明显增加 ,与uPA的结合能力显著增强。结论 :uPAR在膀胱移行细胞癌中的表达明显升高 ,与uPA的结合力明显增强 。

OBJECTIVE:To investigate the combining effect of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) on membrane of transitional cell carcinoma of bladder.METHODS:Eighteen cases with bladder cancer and 6 cases of normal bladder mucosae were quantiated for uPAR on membrane by means of radio-ligand binding assay.RESULTS:The maximal binding capacity (Bmax) of uPAR in bladder cancer membrane and normal bladder mucosae were (420.8±84.6) pmol/g and (84.5±10.4)pmol/g of protein,P<0.01, and the dissociation constants (Kd) were (1.23±0.5) nmol/L and (5.50±1.48) nmol/L,P<0.01,respectively. The number of uPARs on membrane were higher and the blinding was faster with uPA according to increasing malignant degree of cancer.CONCLUSIONS:uPAR plays an important role in invasion and metastasis of transitional cell carcinoma of bladder.