title: SFTG international collaborative study on in vitro micronucleus test I. General conditions and overall conclusions of the study.
abstract: This study, coordinated by the SFTG (French branch of European Environmental Mutagen Society), included 38 participants from Europe, Japan and America. Clastogens (bleomycin, urethane), including base and nucleoside analogs (5-fluorouracil and cytosine arabinoside), aneugens and/or polyploidy inducers (colchicine, diethylstilboestrol, griseofulvin and thiabendazole), as well as non-genotoxic compounds (mannitol and clofibrate), were tested. Four cell types were used, i.e. human lymphocytes in the presence of cytochalasin B and CHO, CHL and L5178Y cell lines, in the presence or absence of cytochalasin B, with various treatment-recovery schedules. Mitomycin C was used as a positive control for all cell types. Mannitol and clofibrate were consistently negative in all cell types and with all treatment-recovery conditions. Urethane, known to induce questionable clastogenicity, was not found as positive. Bleomycin and mitomycin C were found positive in all treatment-recovery conditions. The base and nucleoside analogs were less easy to detect, especially 5-fluorouracil due to the interference with cytotoxicity, while cytosine arabinoside was detected in all cell types depending on the treatment-recovery schedule. Aneugens (colchicine, diethylstilboestrol and griseofulvin) were all detected in all cell types. In this study, the optimal detection was ensured when a short treatment followed by a long recovery was associated with a long continuous treatment without recovery. There was no impact of the presence or absence of cytochalasin B on the detection of micronucleated cells on cell lines. Scoring micronucleated cells in both mononucleated and binucleated cells when using cytochalasin B was confirmed to be useful for the detection and the identification of aneugens. In conclusion, these results, together with previously published validation studies, provide a useful contribution to the optimisation of a study protocol for the detection of both clastogens and aneugens in the in vitro micronucleus test.
authors.affiliation: Servier Group, Drug Safety Assessment, Orleans-Gidy, France. elisabeth.lorge@fr.netgrs.com
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lorge
authors.forename: Veronique
authors.initials: V
authors.lastname: Thybaud
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Aardema
authors.forename: Jo
authors.initials: J
authors.lastname: Oliver
authors.forename: Akihiro
authors.initials: A
authors.lastname: Wakata
authors.forename: Giocondo
authors.initials: G
authors.lastname: Lorenzon
authors.forename: Daniel
authors.initials: D
authors.lastname: Marzin
mesh_terms: D024422:Aneugens / Q000633:toxicity; D000818:Animals; D001761:Bleomycin / Q000633:toxicity; D016466:CHO Cells; D002460:Cell Line; D002994:Clofibrate / Q000633:toxicity; D003078:Colchicine / Q000633:toxicity; D006224:Cricetinae; D003561:Cytarabine / Q000633:toxicity; D003571:Cytochalasin B; D004054:Diethylstilbestrol / Q000633:toxicity; D005472:Fluorouracil / Q000633:toxicity; D006118:Griseofulvin / Q000633:toxicity; D006801:Humans; D066298:In Vitro Techniques; D007391:International Cooperation; D007940:Leukemia L5178; D008214:Lymphocytes / Q000187:drug effects; D008353:Mannitol / Q000633:toxicity; D051379:Mice; D015162:Micronucleus Tests / Q000379:methods* / Q000592:standards; D016685:Mitomycin / Q000633:toxicity; D009153:Mutagens / Q000633:toxicity; D013827:Thiabendazole / Q000633:toxicity
chemical_list: D024422:Aneugens; D009153:Mutagens; D003561:Cytarabine; D001761:Bleomycin; D006118:Griseofulvin; D003571:Cytochalasin B; D008353:Mannitol; D016685:Mitomycin; D004054:Diethylstilbestrol; D002994:Clofibrate; D013827:Thiabendazole; D003078:Colchicine; D005472:Fluorouracil