Saxton R E, Burke M W, Torbett B, Fairhurst M, Morton D L, Cochran A J
Jonsson Comprehensive Cancer Center, UCLA School of Medicine 90024.
Dis Markers. 1988 Jun;6(2):97-108.
Eleven murine monoclonal antibodies (MoAbs) were isolated that defined unique membrane antigens expressed on human melanoma cells but not detectable on human lymphoid cells by radioimmunometric assays. Five of these MoAbs each identified a separate melanoma cell surface antigen as shown by distinctly different in vitro MoAb binding patterns to a diverse panel of tumor cell lines. One of these 5 monoclonals, MoAb 34.1, reacted specifically with 9/11 melanoma lines and 0/28 other human tumor or lymphoid cell lines. The other 4 MoAbs reacted strongly with melanomas, but also bound to 1 or more non-melanoma lines. The remaining 6 MoAbs defined three distinct regions of a single melanoma cell membrane protein with a molecular weight of 125 kiloDaltons (kD) as shown by antibody crossblocking and gel electrophoresis. A sensitive radioimmunoassay developed with MoAbs to 2 epitopes of this 125 kD protein detected up to 500-fold higher levels of this antigen in extracts of melanoma cells compared to autologous lymphoid cells. The 125 kD antigen also was detected by indirect immunoperoxidase assays with the MoAbs on biopsied tumors in histologic tissue sections of 5/11 metastatic melanomas and 1/11 carcinomas but was found on some normal endothelium and smooth muscle. Another monoclonal, MoAb 705, reacted more broadly with tumor cells in 10/14 biopsied melanomas and 10/11 carcinomas, but also was reactive with basal epidermis and normal fibroblasts. By contrast, MoAb 34.1 bound specifically to tumor cells of 7/11 biopsied metastatic melanomas, but bound 0/10 carcinomas and few normal tissues except for some macrophages. Thus, MoAb 34.1 was the most specific diagnostic reagent for immunohistologic detection of melanoma. The 250 kD antigen defined by MoAb 34.1 is similar to a high molecular weight proteoglycan reported to be an excellent tumor marker for human melanomas. The results of these studies show that murine monoclonal antibodies can be used as sensitive reagents for radioimmunoassays and immunohistology of malignant melanoma.
分离出11种鼠单克隆抗体（MoAb），它们可识别在人黑色素瘤细胞上表达的独特膜抗原，但通过放射免疫测定法在人淋巴细胞上无法检测到。其中5种MoAb各自识别一种单独的黑色素瘤细胞表面抗原，这通过与多种肿瘤细胞系明显不同的体外MoAb结合模式得以证明。这5种单克隆抗体中的一种，即MoAb 34.1，与9/11的黑色素瘤细胞系特异性反应，与0/28的其他人类肿瘤或淋巴细胞系无反应。另外4种MoAb与黑色素瘤强烈反应，但也与1种或更多种非黑色素瘤细胞系结合。其余6种MoAb确定了一种分子量为125千道尔顿（kD）的单一黑色素瘤细胞膜蛋白的三个不同区域，这通过抗体交叉阻断和凝胶电泳得以证明。用针对这种125 kD蛋白的2个表位的MoAb开发的一种灵敏放射免疫测定法检测到，与自体淋巴细胞提取物相比，黑色素瘤细胞提取物中该抗原的水平高达500倍。通过用这些MoAb进行间接免疫过氧化物酶测定，在5/11的转移性黑色素瘤和1/11的癌组织切片活检肿瘤中也检测到了125 kD抗原，但在一些正常内皮细胞和平滑肌中也发现了该抗原。另一种单克隆抗体MoAb 705在10/14的活检黑色素瘤和10/11的癌中与肿瘤细胞的反应更广泛，但也与基底表皮和正常成纤维细胞有反应。相比之下，MoAb 34.1特异性结合7/11的活检转移性黑色素瘤的肿瘤细胞，但与0/10的癌无反应，除了一些巨噬细胞外，与很少的正常组织结合。因此，MoAb 34.1是黑色素瘤免疫组织化学检测中最特异的诊断试剂。由MoAb 34.1确定的250 kD抗原类似于一种据报道是人类黑色素瘤优秀肿瘤标志物的高分子量蛋白聚糖。这些研究结果表明，鼠单克隆抗体可作为恶性黑色素瘤放射免疫测定和免疫组织学的灵敏试剂。
