Sequence-specific DNA damage by reactive oxygen species: Implications for carcinogenesis and aging
1Department of Environmental and Molecular Medicine, Mie University School of Medicine, Edobashi 2-174, 514-8507, Tsu, Mie, Japan, s-oikawa@doc.medic.mie-u.ac.jp.
Environmental Health and Preventive Medicine
|March 25, 2011
Summary
Environmental chemicals and UVA radiation cause sequence-specific DNA damage via reactive oxygen species (ROS), contributing to cancer and aging. This study elucidates these mechanisms, highlighting catechol
Area of Science:
- Molecular Biology
- Environmental Health
- Genetics
Background:
- Reactive oxygen species (ROS) from environmental factors induce DNA damage, potentially leading to carcinogenesis and aging.
- Sequence-specific DNA damage is implicated in aging and cancer development.
- Telomere shortening is linked to cellular senescence and aging.
Purpose of the Study:
- To investigate the mechanisms of DNA damage induced by environmental chemicals (catechol, propyl gallate, bisphenol-A), homocysteine, and UVA radiation.
- To explore the role of oxidative DNA damage in catechol-induced carcinogenesis.
- To examine the effect of UVA irradiation on telomere shortening and its underlying DNA damage mechanisms.
Main Methods:
- Utilized human cultured cell lines (HL-60, HP100, WI-38 fibroblasts) and (32)P-labeled DNA fragments.
- Assessed DNA damage by measuring piperidine-labile sites and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation.
- Quantified telomere length changes using terminal restriction fragment length analysis after UVA exposure.
Main Results:
- Catechol induced thymine-specific DNA damage and increased 8-oxodG levels in an H(2)O(2)-dependent manner, suggesting a role in carcinogenesis.
- Bisphenol-A and propyl gallate also caused sequence-specific DNA damage through ROS generation.
- UVA irradiation led to dose-dependent telomere shortening in WI-38 cells, with GGG-specific DNA damage observed in telomeric sequences.
Conclusions:
- Oxidative DNA damage mediated by ROS plays a significant role in the carcinogenic effects of catechol.
- Environmental and dietary factors can induce sequence-specific DNA damage, contributing to cellular damage.
- UVA-induced GGG-specific DNA damage in telomeres contributes to accelerated telomere shortening and cellular aging.
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