title: Effect of a monoclonal anti-carcinoembryonic antigen antibody-ricin A-chain conjugate on human carcinoembryonic antigen-producing tumor cells.
abstract: For the development of therapeutic agents that are coupled to tumor specific carriers, an artificial protein hybrid conjugate (immunotoxin) containing monoclonal anti-carcinoembryonic antigen (CEA) antibody which binds specifically to the cell surface of CEA-producing tumor cells and a toxic subunit of ricin (A-chain) was prepared. This conjugate exerted strong cytotoxicity specifically toward CEA-producing tumor cells in vitro. In vivo, it has anti-tumor effects on ascitic tumor cells, and on free tumor cells before the solid tumor has been established. However, for the established solid tumor, a significant decrease of tumor growth was not seen even after repeated intravenous administrations of the antibody-ricin A-chain conjugate. Furthermore, the conjugate was found to be stable in both mouse and human serum in vitro, but after intravenous injection, it was inactivated in vivo quickly.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D004355:Drug Stability; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D009369:Neoplasms / Q000276:immunology; D009374:Neoplasms, Experimental / Q000188:drug therapy*; D012276:Ricin / Q000008:administration & dosage*
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D002272:Carcinoembryonic Antigen; D012276:Ricin