Maimonis P, Hayes D F, O'Hara C, Kufe D
Laboratory of Clinical Pharmacology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Cancer Res. 1990 Oct 15;50(20):6738-43.
We have defined a human lung carcinoma antigen using murine monoclonal antibodies (DF-L1 and DF-L2) prepared against a primary adenocarcinoma of the lung. This antigen is expressed on the surface of human lung carcinoma cell lines and has an apparent Mr of 350,000-420,000. Immunoperoxidase staining has demonstrated expression of the antigen in the cytoplasm and membranes of adenocarcinomas and squamous cell carcinomas but not small cell tumors of the lung. Immunoprecipitation of the antigen following radiolabeling has demonstrated the presence of both protein and carbohydrate. Antigen purified by immunoaffinity was used to study the epitopes defined by monoclonal antibodies DF-L1 and DF-L2. The results indicate that the DF-L1 epitope primarily involves a peptide structure, while the DF-L2 epitope is comprised in part by peptide and O-linked carbohydrate. In contrast, there was no detectable evidence for the presence of N-linked glycosylation. The results also demonstrate that this antigen circulates at elevated levels in patients with carcinoma of the lung. These findings are similar to previous reports of high molecular weight glycoproteins in breast and ovarian carcinomas. Indeed, the present results in lung cancer identify another member of this heterogeneous family of human carcinoma-associated glycoproteins.
我们利用针对原发性肺腺癌制备的鼠单克隆抗体（DF-L1和DF-L2）定义了一种人肺癌抗原。这种抗原在人肺癌细胞系表面表达，表观分子量为350,000 - 420,000。免疫过氧化物酶染色显示该抗原在腺癌和鳞状细胞癌的细胞质和细胞膜中表达，但在肺小细胞肿瘤中不表达。放射性标记后该抗原的免疫沉淀显示存在蛋白质和碳水化合物。通过免疫亲和纯化的抗原用于研究单克隆抗体DF-L1和DF-L2所定义的表位。结果表明，DF-L1表位主要涉及一种肽结构，而DF-L2表位部分由肽和O-连接的碳水化合物组成。相比之下，没有可检测到的N-连接糖基化的证据。结果还表明，该抗原在肺癌患者体内循环水平升高。这些发现与先前关于乳腺癌和卵巢癌中高分子量糖蛋白的报道相似。事实上，目前肺癌的研究结果确定了这种人类癌相关糖蛋白异质家族的另一个成员。
