Carcinogenic 3-nitrobenzanthrone induces oxidative damage to isolated and cellular DNA.
Free Radic Biol Med
; 40(7): 1242-9, 2006 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-16545693
ABSTRACT
3-Nitrobenzanthrone (3-NBA) is an extremely potent mutagen in diesel exhaust. It is a lung carcinogen to rats, and therefore a suspected carcinogen to human. In order to clarify the mechanism of carcinogenicity of 3-NBA, we investigated oxidative DNA damage by N-hydroxy-3-aminobenzanthrone (N-OH-ABA), a metabolite of 3-NBA, using 32P-labeled DNA fragments from the human p53 tumor-suppressor gene. N-OH-ABA caused Cu(II)-mediated DNA damage, and endogenous reductant NADH dramatically enhanced this process. Catalase and a Cu(I)-specific chelator decreased DNA damage, suggesting the involvement of hydrogen peroxide (H2O2) and Cu(I). N-OH-ABA induced DNA damage at cytosine and guanine residues of ACG sequence complementary to codon 273, a well-known hot spot of the p53 gene. N-OH-ABA dose dependently induced 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in the presence of Cu(II) and NADH. Treatment with N-OH-ABA increased amounts of 8-oxodG in HL-60 cells compared to the H2O2-resistant clone HP100, supporting the involvement of H2O2. The present study has demonstrated that the N-hydroxy metabolite of 3-NBA induces oxidative DNA damage through H2O2 in both a cell-free system and cultured human cells. We conclude that oxidative DNA damage may play an important role in the carcinogenic process of 3-NBA in addition to previously reported DNA adduct formation.
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Base de dados:
MEDLINE
Assunto principal:
Benzo(a)Antracenos
/
Dano ao DNA
/
Carcinógenos
/
Estresse Oxidativo
Idioma:
En
Revista:
Free Radic Biol Med
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Japão