Mitochondrial damage mediates genotoxicity of arsenic in mammalian cells
| Autor: | Tom K. Hei, Su-Xian Liu, Xiuwei Tang, Vladimir N. Ivanov, Mercy M. Davidson, Mohammad Athar, Winsome F. Walker |
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| Rok vydání: | 2005 |
| Předmět: |
Cancer Research
DNA damage Arsenites Arsenic biochemistry chemistry.chemical_element Mutagen CHO Cells Mitochondrion Biology Hybrid Cells medicine.disease_cause DNA Mitochondrial Membrane Potentials Cricetinae Peroxynitrous Acid medicine Animals Humans Arsenic Carcinogen Arsenic toxicity Mutagenicity Tests Proteins Intracellular Membranes Sodium Compounds Mitochondria Oncology chemistry Biochemistry Tyrosine Reactive Oxygen Species Genotoxicity DNA Damage |
| Zdroj: | Cancer research. 65(8) |
| ISSN: | 0008-5472 |
| Popis: | Arsenic is an important environmental carcinogen that affects millions of people worldwide through contaminated water supplies. For decades, arsenic was considered a nongenotoxic carcinogen. Using the highly sensitive AL mutation assay, we previously showed that arsenic is, indeed, a potent gene and chromosomal mutagen and that its effects are mediated through the induction of reactive oxygen species. However, the origin of these radicals and the pathways involved are not known. Here we show that mitochondrial damage plays a crucial role in arsenic mutagenicity. Treatment of enucleated cells with arsenic followed by rescue fusion with karyoplasts from controls resulted in significant mutant induction. In contrast, treatment of mitochondrial DNA–depleted (ρ0) cells produced few or no mutations. Mitochondrial damage can lead to the release of superoxide anions, which then react with nitric oxide to produce the highly reactive peroxynitrites. The mutagenic damage was dampened by the nitric oxide synthase inhibitor, NG-methyl-l-arginine. These data illustrate that mitochondria are a primary target in arsenic-induced genotoxic response and that a better understanding of the mutagenic/carcinogenic mechanism of arsenic should provide a basis for better interventional approach in both treatment and prevention of arsenic-induced cancer. |
| Databáze: | OpenAIRE |
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