Ring D B, Kassel J A, Hsieh-Ma S T, Bjorn M J, Tringale F, Eaton A M, Reid S A, Frankel A E, Nadji M
Cetus Corporation, Department of Immunology, Emeryville, California 94608.
Cancer Res. 1989 Jun 1;49(11):3070-80.
Of 122 mouse monoclonal antibodies selective for human breast cancer, 13 immunoprecipitated an acidic glycoprotein from SK-Br-3 and ZR-75-30 human breast cancer cells. The antigen (BCA200) migrates with an apparent molecular weight of 200,000 on reducing and 180,000 on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting a single polypeptide chain with a folded domain stabilized by a disulfide bond. Cross-blocking and sandwich immunoassays detected at least three distinct antigenic determinants on BCA200. Scatchard experiments measured 1,000,000 to 5,000,000 antigen copies per SK-Br-3 cell. The tissue distribution of BCA200 was studied using two monoclonals to different epitopes. Neither antibody stained any cells in human blood. When frozen sections of 20 normal human tissues were immunoperoxidase stained, the only positive structures were mucinous glands of colon, transitional epithelium of bladder, sweat glands of skin, and acinar epithelium of breast. Antibody 454C11 stained 16 of 21 breast tumor frozen sections and 9 of 12 breast cancer cell lines, while antibody 520C9 stained 5 of 20 breast tumors and 4 of 10 breast cancer lines. Cross-reaction was observed with lung, prostatic, pancreatic, endometrial, and ovarian cancer, but not with lymphoma, melanoma, colon, stomach, bladder, or esophageal cancer. When conjugated to ricin A chain, 10 of 13 antibodies produced immunotoxins selectively cytotoxic to SK-Br-3 breast cancer cells.
在122种对人乳腺癌具有选择性的小鼠单克隆抗体中，有13种能从SK - Br - 3和ZR - 75 - 30人乳腺癌细胞中免疫沉淀出一种酸性糖蛋白。该抗原（BCA200）在还原条件下的十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳中，表观分子量为200,000，在非还原条件下为180,000，这表明它是一条由二硫键稳定折叠结构域的单多肽链。交叉阻断和夹心免疫测定法检测到BCA200上至少有三个不同的抗原决定簇。Scatchard实验测得每个SK - Br - 3细胞中有1,000,000至5,000,000个抗原拷贝。使用针对不同表位的两种单克隆抗体研究了BCA200的组织分布。两种抗体均未对人血液中的任何细胞染色。当对20种正常人体组织的冰冻切片进行免疫过氧化物酶染色时，仅在结肠黏液腺、膀胱移行上皮、皮肤汗腺和乳腺腺泡上皮中出现阳性结构。抗体454C11对21例乳腺肿瘤冰冻切片中的16例以及12种乳腺癌细胞系中的9种呈阳性染色，而抗体520C9对20例乳腺肿瘤中的5例以及10种乳腺癌细胞系中的4种呈阳性染色。在肺癌、前列腺癌、胰腺癌、子宫内膜癌和卵巢癌中观察到交叉反应，但在淋巴瘤、黑色素瘤、结肠癌、胃癌、膀胱癌或食管癌中未观察到。当与蓖麻毒素A链偶联时，13种抗体中的10种产生了对SK - Br - 3乳腺癌细胞具有选择性细胞毒性的免疫毒素。
