Characterization of cluster 13: The epithelial/carcinoma antigen recognized by MAb RS7
Article first published online: 17 JUL 2006
Copyright © 1994 Wiley-Liss, Inc., A Wiley Company
International Journal of Cancer
Supplement: Third International IASLC Workshop on Long Tumor and Differentiation Antigens. University Hospital Zurich, Switzerland
Volume 57, Issue Supplement S8, pages 98–102, 1994
How to Cite
Stein, R., Basu, A., Goldenberg, D. M., Lloyd, K. O. and Mattes, M. Jules. (1994), Characterization of cluster 13: The epithelial/carcinoma antigen recognized by MAb RS7. Int. J. Cancer, 57: 98–102. doi: 10.1002/ijc.2910570721
- Issue published online: 17 JUL 2006
- Article first published online: 17 JUL 2006
- NIH. Grant Number: CA 39841
Cluster 13 was defined by 2 independently derived murine monoclonal antibodies (MAbs), RS7 (IgG1) and MR54 (IgG2a), which were raised against human squamous-cell carcinoma of the lung and a human ovarian-carcinoma cell line, respectively, Immunologic and biochemical evidence demonstrated that RS7 and MR54, as well as 2 additional MAbs, MR6 (IgG2a) and MR23 (IgG1), generated in the same fusion as MR54, recognize the same antigen, a 46- to 48-kDa glycoprotein. Evaluation of the expression of antigen on the surface of tumor cell lines, Western blotting analyses, competitive binding studies, and double-determinant ELISA assays, support this conclusion. Two distinct epitopes are defined by these MAbs.
In order to further characterize this antigen, amino-acid-sequence analyses were performed on peptides derived from antigen purified by affinity chromatography with MAb RS7. The sequence data obtained from 2 peptides, which were independently generated by CNBr cleavage and trypsin digestion respectively indicated identity to GA733-1. The GA733-1 genomic DNA sequence predicted a type-1 membrane protein of 35 kDa, with 4 potential N-linked glycosylation sites. The GA733-1 protein product has not been identified previously, and MAbs to this tumor-associated antigen were not previously known.