title: Cytotoxicity of 213Bi- and 225Ac-immunoconjugates.
abstract: This paper describes in vitro cytotoxicity experiments with 213Bi- and 225Ac-immunoconjugates on the human epidermoid tumour cell line A431 using a blood group A-reactive murine IgG (2D11) as the specific antibody and MOPC 21 as the control antibody. With both radionuclides, specific cell-killing was achieved. The observed cytotoxicity of 213Bi (T1/2 - 47 min) indicates that this radionuclide is a useful alternative for the alpha-emitter 212Bi in the treatment of blood-borne malignancies. 225Ac-immunoconjugates (T1/2 of 225Ac is 10 days) may be applicable for the treatment of solid tumours, since the daughter radionuclides of 225Ac contribute to the cytotoxic efficacy by a field effect (i.e. toxicity in an area distal from the antibody-binding site). The lack of an adequate chelator for 225Ac is a major drawback.
authors.affiliation: NV Organon, Oss.
authors.forename: F M
authors.initials: FM
authors.lastname: Kaspersen
authors.forename: E
authors.initials: E
authors.lastname: Bos
authors.forename: A V
authors.initials: AV
authors.lastname: Doornmalen
authors.forename: M W
authors.initials: MW
authors.lastname: Geerlings
authors.forename: C
authors.initials: C
authors.lastname: Apostolidis
authors.forename: R
authors.initials: R
authors.lastname: Molinet
mesh_terms: D000186:Actinium / Q000633:toxicity*; D000818:Animals; D000918:Antibody Specificity; D001729:Bismuth / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D018796:Immunoconjugates / Q000633:toxicity*; D007074:Immunoglobulin G; D007700:Kinetics; D051379:Mice / Q000276:immunology; D004369:Pentetic Acid; D011868:Radioisotopes / Q000633:toxicity*; D014407:Tumor Cells, Cultured
chemical_list: D018796:Immunoconjugates; D007074:Immunoglobulin G; D011868:Radioisotopes; D004369:Pentetic Acid; D000186:Actinium; D001729:Bismuth