Zylstra S, Chen F A, Ghosh S K, Repasky E A, Rao U, Takita H, Bankert R B
Cancer Res. 1986 Dec;46(12 Pt 1):6446-51.
A monoclonal antibody (5E8) has been used to identify and structurally characterize a previously unreported macromolecule present on the surface of human lung tumors. This antibody was derived from a hybrid clone that was produced using spleen cells of mice immunized with a surgically excised squamous cell carcinoma. Using immunofluorescence, the 5E8 antibody was observed to stain many different human lung tumor cell lines and surgically excised human lung tumors including squamous cell carcinomas, adenocarcinomas, alveolar carcinomas, and a portion of the large cell tumors tested. With few exceptions, notably the basal layer of the skin, little or no detectable staining of 5E8 to normal human tissues (lung, brain, kidney, heart, stomach, breast, erythrocytes, or lymphocytes) was observed. The 5E8 antibody was used to immunoprecipitate detergent lysates of biosynthetically labeled or surface radioiodinated lung tumors. Analysis of the immunoprecipitates by sodium dodecyl sulfate gel electrophoresis revealed a major band and a faster migrating second minor band. The molecular weights of these two proteins were estimated to be 160,000 and 120,000, respectively. The addition of a reducing agent to the gels did not alter the migration pattern of the immunoprecipitated macromolecules. The removal of a terminal carbohydrate, sialic acid, did not restrict the binding of 5E8 to the tumor-associated antigen. However, labeling studies using galactose oxidase and tritiated borohydride revealed the presence of galactose on the immunoprecipitated protein. This major Mr 160,000 glycoprotein that was identified on two different human lung tumor cell lines was also found on a human large cell tumor tissue obtained by surgical biopsy. The 5E8 antibody and the Mr 160,000 glycoprotein that it recognizes represent two very useful components with which to test several new antibody-mediated drug delivery systems in the treatment of human lung tumors. The tumor-associated glycoprotein also represents a potential analyte for a diagnostic or prognostic immunoassay for lung cancer.
一种单克隆抗体（5E8）已被用于鉴定和从结构上表征人肺肿瘤表面存在的一种先前未报道的大分子。该抗体源自一个杂交克隆，该克隆是用手术切除的鳞状细胞癌免疫的小鼠脾细胞产生的。使用免疫荧光法，观察到5E8抗体可对许多不同的人肺肿瘤细胞系以及手术切除的人肺肿瘤进行染色，包括鳞状细胞癌、腺癌、肺泡癌以及所检测的一部分大细胞肿瘤。除少数例外情况，特别是皮肤的基底层，未观察到5E8对正常人组织（肺、脑、肾、心脏、胃、乳腺、红细胞或淋巴细胞）有明显或可检测到的染色。5E8抗体用于免疫沉淀生物合成标记或表面放射性碘化的肺肿瘤的去污剂裂解物。通过十二烷基硫酸钠凝胶电泳对免疫沉淀物进行分析，显示出一条主要条带和一条迁移较快的次要条带。这两种蛋白质的分子量估计分别为160,000和120,000。向凝胶中添加还原剂不会改变免疫沉淀的大分子的迁移模式。去除末端碳水化合物唾液酸并不限制5E8与肿瘤相关抗原的结合。然而，使用半乳糖氧化酶和氚化硼氢化钠的标记研究表明，免疫沉淀的蛋白质上存在半乳糖。在两种不同的人肺肿瘤细胞系上鉴定出的这种主要的分子量为160,000的糖蛋白，在通过手术活检获得的人肺大细胞肿瘤组织中也被发现。5E8抗体及其识别的分子量为160,000的糖蛋白是两种非常有用的成分，可用于测试几种新的抗体介导的药物递送系统在治疗人肺肿瘤中的应用。这种肿瘤相关糖蛋白也代表了一种用于肺癌诊断或预后免疫测定的潜在分析物。
