Langkilde N C, Wolf H, Clausen H, Orntoft T F
Department of Experimental Clinical Oncology, Danish Cancer Society, Aarhus.
Cancer Res. 1992 Sep 15;52(18):5030-6.
T- and T-like antigens on glycoproteins and glycolipids were examined in extracts of human urinary bladder tumors and normal tissue by Western blot analysis and reagent binding to thin layer chromatograms. Three different anti-T-reagents were used: peanut (Arachis hypogaea) lectin (PNA) and mono- and polyclonal antibodies specific for T-antigen (Gal beta(1-3)GalNAc alpha 1-O-R). Immunodetection with the T-specific reagents in nitrocellulose replicas of bladder tumor glycoproteins, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, demonstrated tumor-specific T-antigen-bearing glycoproteins compared to normal urothelial glycoproteins. In addition, a remarkable difference in binding was found between the immunological reagents and PNA lectin. PNA showed major reactivity to a 28-kD glycoprotein extracted from tumors. Monoclonal anti-T-antibody (clone HH8) showed major reactivity with an M(r) 34,000 glycoprotein, and polyclonal anti-T-antibody showed major reactivity with an M(r) 36,000 glycoprotein. PNA agarose column affinity-purified tumor glycoproteins did not bind the antibodies. Glycoproteins, M(r) 28,000 and 34,000, were shown to be O-linked by stepwise deglycosylation. In solid phase monosaccharide inhibition tests, galactose followed by N-acetyl-galactosamine were the most potent monosaccharides inhibiting binding to immobilized bladder tumor glycoproteins. None of the anti-T-reagents reacted with glycolipids extracted from tumor tissue. It is concluded that PNA lectin, in addition to the T-disaccharide, reacts with other protein-anchored carbohydrate structures in carcinomas.
通过蛋白质免疫印迹分析以及试剂与薄层层析图谱的结合,对人膀胱肿瘤和正常组织提取物中的糖蛋白和糖脂上的T及T样抗原进行了检测。使用了三种不同的抗T试剂:花生(花生属)凝集素(PNA)以及对T抗原(Galβ(1-3)GalNAcα1-O-R)具有特异性的单克隆和多克隆抗体。在经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离的膀胱肿瘤糖蛋白的硝酸纤维素复制品中,用T特异性试剂进行免疫检测,结果显示与正常尿路上皮糖蛋白相比,存在肿瘤特异性的携带T抗原的糖蛋白。此外,还发现免疫试剂与PNA凝集素之间在结合上存在显著差异。PNA对从肿瘤中提取的一种28-kD糖蛋白具有主要反应性。单克隆抗T抗体(克隆HH8)对一种分子量为34,000的糖蛋白具有主要反应性,多克隆抗T抗体对一种分子量为36,000的糖蛋白具有主要反应性。PNA琼脂糖柱亲和纯化的肿瘤糖蛋白不与抗体结合。通过逐步去糖基化显示,分子量为28,000和34,000的糖蛋白为O-连接型。在固相单糖抑制试验中,半乳糖随后是N-乙酰半乳糖胺是抑制与固定化膀胱肿瘤糖蛋白结合的最有效单糖。没有一种抗T试剂与从肿瘤组织中提取的糖脂发生反应。结论是,除了T二糖外,PNA凝集素还与癌组织中其他蛋白质锚定的碳水化合物结构发生反应。