Journal Article

Induction of oxidative DNA damage by arsenite and its trivalent and pentavalent methylated metabolites in cultured human cells and isolated DNA

Tanja Schwerdtle, Ingo Walter, Iris Mackiw and Andrea Hartwig

in Carcinogenesis

Volume 24, issue 5, pages 967-974
Published in print May 2003 | ISSN: 0143-3334
Published online May 2003 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/bgg018
Induction of oxidative DNA damage by arsenite and its trivalent and pentavalent methylated metabolites in cultured human cells and isolated DNA

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

Even though a well-known human carcinogen the underlying mechanisms of arsenic carcinogenicity are still not fully understood. For arsenite, proposed mechanisms are the interference with DNA repair processes and an increase in reactive oxygen species. Even less is known about the genotoxic potentials of its methylated metabolites monomethylarsonous [MMA(III)] and dimethylarsinous [DMA(III)] acid, monomethylarsonic [MMA(V)] and dimethylarsinic [DMA(V)] acid. Within the present study we compared the induction of oxidative DNA damage by arsenite and its methylated metabolites in cultured human cells and in isolated PM2 DNA, by frequencies of DNA strand breaks and of lesions recognized by the bacterial formamidopyrimidine–DNA glycosylase (Fpg). Only DMA(III) (≥10 µM) generated DNA strand breaks in isolated PM2 DNA. In HeLa S3 cells, short-term incubations (0.5–3 h) with doses as low as 10 nM arsenite induced high frequencies of Fpg-sensitive sites, whereas the induction of oxidative DNA damage after 18 h incubation was rather low. With respect to the methylated metabolites, both trivalent and pentavalent metabolites showed a pronounced induction of Fpg-sensitive sites in the nanomolar or micromolar concentration range, respectively, which was present after both short-term and long-term incubations. Furthermore MMA(III) and DMA(V) generated DNA strand breaks in a concentration-dependent manner. Taken together our results show that very low physiologically relevant doses of arsenite and the methylated metabolites induce high levels of oxidative DNA damage in cultured human cells. Thus, biomethylation of inorganic arsenic may be involved in inorganic arsenic-induced genotoxicity/carcinogenicity.

Keywords: AP sites, apurinic/apyrimidinic sites; DMA(III), dimethylarsinous acid; DMA(V), dimethylarsinic acid; MMA(III), monomethylarsonous acid; MMA(V), monomethylarsonic acid.

Journal Article.  6401 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.