Increased mutant frequency by carbon black, but not quartz, in the lacZ and cII transgenes of muta mouse lung epithelial cells.
Carbon black and quartz are relatively inert solid particulate materials that are carcinogenic in laboratory animals. Quartz is a human carcinogen, whereas data on carbon black are contradictory, and there are few data on mammalian mutagenesis. We determined the mutant frequency following eight repeated 72-hr incubations with 75 mug/ml carbon black (Printex 90) or 100 mug/ml quartz (SRM1878a) particles in the FE1 Muta Mouse lung epithelial cell line. For carbon black exposed cells, the mutant frequency was 1.40-fold (95% CI: 1.22-1.58) for cII and 1.23-fold (95% CI: 1.10-1.37) for lacZ compared with identically passaged untreated cells. Quartz did not significantly affect the mutant frequency. Carbon black also induced DNA strand breaks (P = 0.02) and oxidized purines (P = 0.008), as measured by the Comet assay. Quartz induced marginally more oxidized purines, but no change in strand breaks. We detected five (phenanthrene, flouranthene, pyrene, benzo[a]anthracene, and chrysene) of the 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) in an extract of carbon black. The detected PAHs are only weakly mutagenic compared with benzo[a]pyrene, and were present in very low amounts. In conclusion, carbon black was weakly mutagenic in vitro at the cII and lacZ loci. It also induced DNA strand breaks and oxidized DNA bases. More studies are essential for understanding the biological significance of these findings, and clearly documenting DNA sequence changes. The results do not necessarily imply that other carbonaceous nano materials are genotoxic.
Jacobsen
Nicklas Raun
NR
National Research Centre for the Working Environment, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark.
Saber
Anne Thoustrup
AT
White
Paul
P
Møller
Peter
P
Pojana
Giulio
G
Vogel
Ulla
U
Loft
Steffen
S
Gingerich
John
J
Soper
Lynda
L
Douglas
George R
GR
Wallin
Håkan
H
D000818:Animals; D002452:Cell Count; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004249:DNA Damage; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007763:Lac Operon / Q000235:genetics*; D008168:Lung / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D009154:Mutation / Q000235:genetics*; D052638:Particulate Matter / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011743:Pyrimidines / Q000633:toxicity; D011791:Quartz / Q000633:toxicity*; D053260:Soot / Q000633:toxicity*; D014157:Transcription Factors / Q000235:genetics*; D019076:Transgenes / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics*
D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D011743:Pyrimidines; D053260:Soot; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; D011791:Quartz; D007770:L-Lactate Dehydrogenase