Carcinoembryonic antigen from human malignant melanoma cells. II. Grafting of the cells in the hamster cheek pouch.

The preceding paper described production and release of carcinoembryonic antigen (CEA) by in vitro culture of the human malignant melanotic melanoma (HMMC-ShAE+) cell line; the present paper reports on two findings related to CEA biofunction. 1) The function of cell membrane oligosaccharides on the antigen-antibody reaction, i.e. the binding of 125I-labelled monoclonal anti-HMMC-ShAE+ antibodies to enzymically modified HMMC-ShAE+ cells. In these experiments, two approaches were used: sequential treatment with exohydrolases and cultivation of the cells in media supplemented with nontoxic levels of tunicamycin and swainsonine. 2) The effect of grafting, into the hamster cheek pouch, of modified HMMC-ShAE+ cells on plasma CEA, plasma anti-CEA and antibody-dependent cell-mediated cytotoxicity. Commercially available 125I-labelled CEA and the "Abbott" enzyme-linked immunoassay were used to monitor plasma anti-CEA and CEA levels, respectively. 125I-deoxyuridine-labelled HMMC-ShAE+ were used to monitor plasma antibody-dependent cell-mediated cytotoxicity.