title: DNA damage by singlet oxygen and cellular protective mechanisms.
abstract: Reactive oxygen species, as singlet oxygen ((1)O(2)) and hydrogen peroxide, are continuously generated by aerobic organisms, and react actively with biomolecules. At excessive amounts, (1)O(2) induces oxidative stress and shows carcinogenic and toxic effects due to oxidation of lipids, proteins and nucleic acids. Singlet oxygen is able to react with DNA molecule and may induce G to T transversions due to 8-oxodG generation. The nucleotide excision repair, base excision repair and mismatch repair have been implicated in the correction of DNA lesions induced by (1)O(2) both in prokaryotic and in eukaryotic cells. (1)O(2) is also able to induce the expression of genes involved with the cellular responses to oxidative stress, such as NF-κB, c-fos and c-jun, and genes involved with tissue damage and inflammation, as ICAM-1, interleukins 1 and 6. The studies outlined in this review reinforce the idea that (1)O(2) is one of the more dangerous reactive oxygen species to the cells, and deserves our attention.
authors.affiliation: Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Lucymara F
authors.initials: LF
authors.lastname: Agnez-Lima
authors.forename: Julliane T A
authors.initials: JT
authors.lastname: Melo
authors.forename: Acarízia E
authors.initials: AE
authors.lastname: Silva
authors.forename: Ana Helena S
authors.initials: AH
authors.lastname: Oliveira
authors.forename: Ana Rafaela S
authors.initials: AR
authors.lastname: Timoteo
authors.forename: Keronninn M
authors.initials: KM
authors.lastname: Lima-Bessa
authors.forename: Glaucia R
authors.initials: GR
authors.lastname: Martinez
authors.forename: Marisa H G
authors.initials: MH
authors.lastname: Medeiros
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Mascio
authors.forename: Rodrigo S
authors.initials: RS
authors.lastname: Galhardo
authors.forename: Carlos F M
authors.initials: CF
authors.lastname: Menck