Carcinogenesis Advance Access originally published online on January 3, 2008
Carcinogenesis 2008 29(2):427-433; doi:10.1093/carcin/bgm243
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Clastogenic and aneugenic effects of multi-wall carbon nanotubes in epithelial cells
Unité de toxicologie industrielle et médecine du travail, Université catholique de Louvain, Avenue Mounier, 53.02, 1200 Bruxelles, Belgium
1 Laboratorium voor Cellulaire Genetica, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
2 Laboratorium voor Pneumologie, Katholieke Universiteit Leuven, Eenheid Longtoxicologie, Herestraat 49, 3000 Leuven, Belgium
3 Centrum voor Oppervlaktechemie en Katalyse, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Heverlee, Belgium
* To whom correspondence should be addressed. Tel: +32 2 764 53 36; Fax: +32 2 764 53 38; Email: julie.muller{at}uclouvain.be
Information on the toxicity of carbon nanotubes is still fragmentary but indicates that these particles can induce adverse effects. We previously demonstrated in rats that, when purified multi-wall carbon nanotubes (MWCNT) reach the lung, they are biopersistent and induce lung inflammation as well as fibrosis. The present study was designed to address the genotoxic potential of this material in the same species. In vivo, micronuclei (MN) were assessed in type II pneumocytes 3 days after a single intra-tracheal administration of MWCNT (0.5 or 2 mg). We also used the cytokinesis-block micronucleus assay in rat lung epithelial cells exposed in vitro to MWCNT (10, 25, 50 µg/ml). Finally, we applied a human pancentromeric fluorescent probe (fluorescent in situ hybridization assay) to differentiate clastogenic and/or aneugenic mechanisms in a human epithelial cell line (MCF-7). In vivo, we found a significant and dose-dependent increase in micronucleated pneumocytes after a single administration of MWCNT (
a 2-fold increase at the highest dose). In vitro, we observed a significant increase of MN in epithelial cells after exposure to MWCNT (up to a 2-fold increase at the cytotoxic dose of 50 µg/ml). Finally, we found that MWCNT induced both centromere-positive and -negative MN in MCF-7 cells. Overall, this study provides the first evidence of the potential of MWCNT to induce clastogenic as well as aneugenic events.
Abbreviations: CB, binucleated cells; CBPI, cytokinesis-block proliferation index; CNT, carbon nanotubes; FCS, fetal calf serum; FISH, fluorescent in situ hybridization; FITC, fluorescein isothiocyanate; LDH, lactate dehydrogenase; MN, micronuclei; MNCB, micronucleated binucleates; MTT, dimethylthiazole–tetrazolium; MWCNT, multi-wall carbon nanotube; PI, propidium iodide; RLE, rat lung epithelial; ROS, reactive oxygen species; WC–Co, tungsten carbide–cobalt mixture
Received May 23, 2007; revised October 25, 2007; accepted October 26, 2007.