title: DNA-protein cross-links and sister chromatid exchanges induced by dimethylarsinic acid in human fibroblasts cells.
abstract: Biotransformation of inorganic arsenic to form both methylarsinic acid (MA) and dimethylarsinic acid (DMA) has traditionally been considered as a mechanism to facilitate the detoxification and excretion of arsenic. However, the methylation of inorganic arsenic as a detoxification mechanism has been questioned due to recent studies revealing an important role of organic arsenic in the induction of genetic damage. In a previous report a reduction of DNA migration after treatment of cells with DMA was described. In order to further evaluate the possible induction of protein-DNA adducts, an experiment was performed taking into account other parameters and modifications of the standard alkaline comet assay. In addition, the results obtained with the comet assay were compared with those obtained by analyzing the induction of sister chromatid exchanges (SCEs). SCE frequencies were significantly increased in treated cells in relation to controls (p<0.001). Furthermore, in the standard alkaline comet assay, as well as in the control assay for proteinase K treatment, a significant dose-dependent reduction in tail moment was observed. Nevertheless, the post-treatment with proteinase K induced the release of proteins joined to the DNA and consequently, a dose-dependent increment in DNA migration was observed (p<0.001). These results suggest that DNA-protein cross-links may be an important genotoxic effect induced by dimethylarsinic acid in human MRC-5 cells.
authors.affiliation: Centro de Investigaciones en Genética Básica y Aplicada (CIGEBA), Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118 s/n, B1900A V W, La Plata, Buenos Aires, Argentina.
authors.forename: Silvana Andrea
authors.initials: SA
authors.lastname: Mourón
authors.forename: Claudia Alejandra
authors.initials: CA
authors.lastname: Grillo
authors.forename: Fernando Noel
authors.initials: FN
authors.lastname: Dulout
authors.forename: Carlos Daniel
authors.initials: CD
authors.lastname: Golijow
mesh_terms: D000818:Animals; D002101:Cacodylic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D020552:Comet Assay; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006540:Herbicides / Q000494:pharmacology*; D006801:Humans; D011506:Proteins / Q000378:metabolism*; D012854:Sister Chromatid Exchange
chemical_list: D006540:Herbicides; D011506:Proteins; D004247:DNA; D002101:Cacodylic Acid