Wong C, Waibel R, Sheets M, Mach J P, Finnern R
University of Lausanne, Department of Biochemistry, Epalinges, Switzerland.
Cancer Immunol Immunother. 2001 Apr;50(2):93-101. doi: 10.1007/s002620100174.
New anti-cancer agents are being developed that specifically recognise tumour cells. Recognition is dependent upon the enhanced expression of antigenic determinants on the surface of tumour cells. The tumour exposure and the extracellular accessibility of the mucin MUC-1 make this marker a suitable target for tumour diagnosis and therapy. We isolated and characterised six human scFv antibody fragments that bound to the MUC-1 core protein, by selecting a large naive human phage display library directly on a MUC-1-expressing breast carcinoma cell line. Their binding characteristics have been studied by ELISA, FACS and indirect immunofluorescence. The human scFv antibody fragments were specific for the tandem repeat region of MUC-1 and their binding is inhibited by soluble antigen. Four human scFv antibody fragments (M2, M3, M8, M12) recognised the hydrophilic PDTRP region of the MUC-1 core protein, which is thought to be an immunodominant region. The human scFv antibody fragments were stable in human serum at 37 degrees C and retained their binding specificity. For imaging or targeting to tumours over-expressing MUC-1, it might be feasible to use these human scFv, or multivalent derivatives, as vehicles to deliver anti-cancer agents.
新型抗癌药物正在研发中，这些药物能够特异性识别肿瘤细胞。识别过程依赖于肿瘤细胞表面抗原决定簇表达的增强。黏蛋白MUC-1在肿瘤中的暴露情况及其细胞外可及性，使得该标志物成为肿瘤诊断和治疗的合适靶点。我们通过直接在表达MUC-1的乳腺癌细胞系上筛选一个大型天然人噬菌体展示文库，分离并鉴定了六个与MUC-1核心蛋白结合的人单链抗体片段。通过酶联免疫吸附测定（ELISA）、荧光激活细胞分选术（FACS）和间接免疫荧光法研究了它们的结合特性。人单链抗体片段对MUC-1的串联重复区域具有特异性，其结合可被可溶性抗原抑制。四个单链抗体片段（M2、M3、M8、M12）识别MUC-1核心蛋白的亲水性PDTRP区域，该区域被认为是一个免疫显性区域。人单链抗体片段在37℃的人血清中稳定，并保留其结合特异性。对于成像或靶向过表达MUC-1的肿瘤，使用这些人单链抗体或多价衍生物作为载体来递送抗癌药物可能是可行的。
