Effect of N-Acetyl Cysteine on Oxidative DNA Damage and the Frequency of DNA Deletions in Atm-Deficient Mice

R Reliene, E Fischer, RH Schiestl - Cancer research, 2004 - AACR
Cancer research, 2004AACR
Ataxia telangiectasia (AT) is a hereditary human disorder resulting in a wide variety of
clinical manifestations, including progressive neurodegeneration, immunodeficiency, and
high incidence of lymphoid tumors. Cells from patients with AT show genetic instability,
hypersensitivity to radiation, and a continuous state of oxidative stress. Oxidative stress and
genetic instability, including DNA deletions, are involved in carcinogenesis. We examined
the effect of dietary supplementation with the thiol-containing antioxidant N-acetyl-l-cysteine …
Abstract
Ataxia telangiectasia (AT) is a hereditary human disorder resulting in a wide variety of clinical manifestations, including progressive neurodegeneration, immunodeficiency, and high incidence of lymphoid tumors. Cells from patients with AT show genetic instability, hypersensitivity to radiation, and a continuous state of oxidative stress. Oxidative stress and genetic instability, including DNA deletions, are involved in carcinogenesis. We examined the effect of dietary supplementation with the thiol-containing antioxidant N-acetyl-l-cysteine (NAC) on levels of oxidative DNA damage and the frequency of DNA deletions in Atm-deficient (AT-mutated) mice. We confirmed that Atm-deficient mice display an increased frequency of DNA deletions (Bishop et al., Cancer Res 2000;60:395). Furthermore, we found that Atm-deficient mice have significantly increased levels of 8-OH deoxyguanosine, an indication of oxidative DNA damage. Dietary supplementation with NAC significantly reduced 8-OH deoxyguanosine level and the frequency of DNA deletions in Atm-deficient mice. These levels were similar to the levels in wild-type mice. Our findings demonstrate that NAC counteracts genetic instability and suggest that genetic instability may be a consequence of oxidative stress in Atm-deficient mice.
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