title: Targeting immunotherapy using the avidin-biotin system for a human colon adenocarcinoma in vitro.
abstract: A new method of targeting immunotherapy using the avidin-biotin system in vitro was investigated. Both an anti-carcinoembryonic antigen monoclonal antibody (anti-CEA MAb) and an anti-cancer drug, neocarzinostatin (NCS), were biotinylated. A human colon adenocarcinoma cell line (LoVo) was immunized with biotinylated anti-CEA MAb; avidin was added, and the cell line was incubated with various concentrations of biotinylated NCS for either 72 h or 7 min. In the incubation for 72 h, the IC50 was similar (approximately 0.45 microgram/ml) for biotinylated NCS for LoVo cells immunized with biotinylated anti-CEA MAb and those without immunization. In the incubation for 7 min, the IC50 (concentration producing 50% cytotoxicity) of biotinylated NCS for LoVo cells immunized with biotinylated anti-CEA MAb (0.35 microgram/ml) was five times less than that of non-immunized LoVo cells (1.8 micrograms/ml). Thus the present system has the potential to reduce the dosage of anti-cancer drugs needed, and this strategy seems likely to be a valuable clinical tool in targeting immunotherapy.
authors.affiliation: Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakaki
authors.forename: H
authors.initials: H
authors.lastname: Takikawa
authors.forename: M
authors.initials: M
authors.lastname: Yamanaka
mesh_terms: D000230:Adenocarcinoma / Q000628:therapy*; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal; D001360:Avidin / Q000737:chemistry; D001710:Biotin / Q000737:chemistry; D002272:Carcinoembryonic Antigen / Q000737:chemistry / Q000276:immunology*; D002462:Cell Membrane / Q000737:chemistry / Q000276:immunology; D003110:Colonic Neoplasms / Q000628:therapy*; D003601:Cytotoxicity Tests, Immunologic; D004354:Drug Screening Assays, Antitumor; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D014407:Tumor Cells, Cultured; D009353:Zinostatin / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D000903:Antibiotics, Antineoplastic; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D001360:Avidin; D001710:Biotin; D009353:Zinostatin