This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ogasawara, M. Articles by Ishii, K. Search for Related Content PubMed PubMed Citation Articles by Ogasawara, M. Articles by Ishii, K.

Tumor-associated Antigen Defined by a Monoclonal Antibody against Neuraminidase-treated Human Cancer Cells

The Second Department of Medicine, Asahikawa Medical College, Nishikagura 4-5-3-11, Asahikawa 078, Japan

A monoclonal antibody, MH-A6, was produced by immunization with a human gastric cancer cell line, MKN 74, treated with neuroaminidase. The antigen defined by the monoclonal antibody was detected on various tumor tissues and a limited number of normal tissues in immunoperoxidase assay, and the expression of MH-A6 antigen was not influenced by neuraminidase treatment except for some cases of tumor tissues. Interestingly, neuraminidase treatment enhanced binding of the antibody on some adenocarcinomas, but diminished binding of the antibody on squamous cell carcinomas. Both treatment of the immunizing tissues with trypsin and periodic acid diminished binding of the antibody. In isolation of MH-A6 antigen from MKN 74 cells by the monoclonal antibody coupled-affinity column, the epitope exists on molecules with molecular weights of 30,000 and 72,000, and with an acidic pH range in two-dimensional electrophoresis. CEA and CA 19-9 activities were not detected in purified MH-A6 antigen by solid-phase radioimmunoassay, and the reactivity of the MH-A6 antibody with CEA and CA 19-9 was not detected in enzyme-linked immunosorbent assay. Hemagglutination observed between erythrocytes (Lewis^a, Lewis^b, or NE-treated) and anti-Lewis^a, anti-Lewis^b sera, or anti-T-agglutinin (peanut lectin), respectively, was not inhibited by MH-A6 antigen. The results suggest that MH-A6 antigen is a tumor-associated antigen, probably glycoprotein, and different from CEA, CA 19–9, Lewis^a, Lewis^b, and Thomsen-Friedreich (T) antigen.

¹ To whom requests for reprints should be addressed.

Received 9/ 8/86. Revised 6/26/87. Revised 10/ 7/87. Accepted 10/13/87.