[On the clinical usefulness of a few sugar antigens and a galactosyl-transferase].

Using human cultured cell lines or lymphocytes, two kinds of murine- and one human-monoclonal antibodies were produced, respectively and their clinical usefulness were investigated, and the possibility of galactosyl-transferase as a new tumor maker was also discussed. (1) A murine monoclonal antibody MSN-1, which was raised against human endometrial cancer cell line and recognized blood type sugar chain Leb, reacted with about 85% of endometrial cancer tissues, indicating that useful clinical information may be obtained by applying MSN-1 to immunohistochemistry and flow cytometry. (2) A new assay system using two murine monoclonal antibodies MA54 and MA61, which were raised against human lung cancer cell line and reacted with mucin sugar residues, revealed 76% positive rate in ovarian cancer patients, especially 82% in mucinous cystadenocarcinoma, indicating the clinical effectiveness as a new tumor maker compensating for the drawbacks of CA-125. (3) Galactosyl-transferase isozyme GT-2 was analyzed by the assay system using a newly produced monoclonal antibody. GT-2 was positive in 74% of ovarian cancers, especially in 89% of meso-nephroid cancer, indicating that GT-2 could be a useful tumor maker in ovarian tumors. (4) Human monoclonal antibody, which recognized "type 1 sugar chain" or iso-paragloboside, reacted about one half of endometrial cancer tissues. The production of human monoclonal antibody may contribute to the cancer imaging and the missile therapy.