CHROMIUM-INDUCED GENOTOXICITY AND INTERFERENCE IN HUMAN LYMPHOBLASTOID CELL (TK6) REPAIR PROCESSES

Marcos, Ricard; Stoyanova, Elitsa; El-Yamani, Naouale; Creus, Amadeu; Zuniga, Liliana

Abstract

Two model chromium (Cr) compounds, one hexavalent (sodium chromate) and one trivalent (chromium chloride), were investigated in a human lymphoblastoid cell line (TK6) to increase our knowledge regarding Cr-induced genotoxicity mechanisms. Both selected compounds were genotoxic using the comet assay, although the percentage of DNA in tail obtained after treatment with Cr-VI was significantly higher than that obtained with Cr-III, at the higher concentrations tested. To determine the nature of the induced damage, enzymes recognizing oxidized bases were used. Treatments with formamidopyrimidine (FPG) and endonuclease III (EndoIII) displayed a greater degree of DNA damage, indicating that the induction of oxidized bases accounts for an important proportion of the damage induced by Cr compounds. In addition, the kinetic repair studies showed that generated DNA damage is removed in approximately 8 h, with the damage induced by Cr-III being removed/repaired more rapidly than damage produced by Cr-VI. To detect Cr interferences with the repair process, a post-treatment was applied after exposure to 2 Gy gamma radiation. Post-treatment significantly delayed the repair kinetics of DNA damage induced by radiation. This interference effect induced by Cr-VI was more pronounced. In conclusion, evidence indicates that a high proportion of the Cr-induced DNA damage is correlated with oxidative damage, and that both Cr compounds interfere with repair mechanisms involved in repair of DNA damage induced by gamma radiation.

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Título según WOS: ID WOS:000294904400008 Not found in local WOS DB
Título de la Revista: JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A-CURRENT ISSUES
Volumen: 74
Número: 15-16
Editorial: TAYLOR & FRANCIS INC
Fecha de publicación: 2011
Página de inicio: 1030
Página final: 1039
DOI:

10.1080/15287394.2011.582282

Notas: ISI