SFTG international collaborative study on in vitro micronucleus test. II. Using human lymphocytes
Por:
Clare M.G., Lorenzon G., Akhurst L.C., Marzin D., van Delft J., Montero R., Botta A., Bertens A., Cinelli S., Thybaud V., Lorge E.
Publicada:
1 ene 2006
Resumen:
This study on the in vitro micronucleus assay, comprising 11 laboratories using human lymphocytes, was coordinated by an organizing committee supported by the SFTG (the French branch of the European Environmental Mutagen Society). Nine coded substances were assessed for their ability to induce micronuclei in human lymphocytes in vitro, mitomycin C being used as a positive control. Cultures were exposed to the test substances for a short (early or late) time or for a long time, followed by a short or long recovery period, in the presence of cytochalasin B. Each chemical was evaluated, generally in two laboratories, using three treatment schedules at least twice. The data were assessed for acceptability, and then classified as negative, positive or equivocal. Two of seven genotoxic compounds, namely colchicine and bleomycin, clearly induced micronuclei. Reproducible results were difficult to obtain for some substances, which tended to be those acting at specific stages of the cell cycle. Cytosine arabinoside, diethylstilboestrol and 5-fluorouracil were classified as equivocal. Urethane and thiabendazole were classified as negative. The two presumed non-genotoxic compounds, mannitol and clofibrate, did not induce micronuclei. Repeat testing, exposing cells at both an early and late time after mitogenic stimulation, was needed to detect substances classified as equivocal. These results show the importance of achieving sufficient inhibition of nuclear division to avoid the possibility of missing an effect. The evaluation of micronuclei in mononucleated as well as binucleated cells was particularly useful to detect aneugens. There were no false positive results using lymphocytes, indicating a high specificity. It is concluded that the clastogenic or aneugenic potential in vitro of the substances tested was correctly identified in this study, but that refining the protocol to take into account factors such as the stages of the cell cycle exposed to the compound, or the duration of recovery would be likely to improve the sensitivity of detection using lymphocytes. © 2006 Elsevier B.V. All rights reserved.
Filiaciones:
Clare M.G.:
Department of Genetic Toxicology, Safety Assessment, Astra Charnwood, Bakewell Road, Loughborough, Leics. LE115RH, United Kingdom
Lorenzon G.:
ProStrakan Pharmaceuticals, F-93230 Romainville, France
Akhurst L.C.:
Huntingdon Life Sciences, Department of Genetic Toxicology, Woolley Road, Cambridgeshire PE28 4HS, United Kingdom
Marzin D.:
Institut Pasteur, Laboratoire de Toxicologie, F-59019 Lille, France
van Delft J.:
TNO Nutrition and Food Research Institute, Toxicology Division, P.O. Box 360, 3700 AJ Zeist, Netherlands
Montero R.:
Universidad Nacional Autonoma de México, Instituto de Investigaciones Biomédicas, Genetica Toxicologia Ambiantale, Apdo. Postal 70228, C.P. 04510 Mexico D.F., Mexico
Botta A.:
Universite d'Aix Marseille II, Laboratoire de Biogenotoxicologie, F-13385 Marseille, France
Bertens A.:
Notox B.V., PO Box 3475, 5203 DL's-Hertogenbosch, Netherlands
Cinelli S.:
Research Toxicology Center, via Tito Speri 12, 00040 Pomezia, Rome, Italy
Thybaud V.:
Sanofi Aventis, Drug Safety Evaluation, F-94400 Vitry-sur-Seine, France
Lorge E.:
Servier Group, Drug Safety Assessment, F-45403 Orleans-Gidy, France
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