ArticleChemical research in toxicology2010
Redox cycling of catechol estrogens generating apurinic/apyrimidinic sites and 8-oxo-deoxyguanosine via reactive oxygen species differentiates equine and human estrogens.
Article in Chemical research in toxicology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 1 of them a synthesis that pooled it.
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Who cites it
23 citing papers in PubMed, 1 synthesis or guideline pooled it, 47 citations in OpenAlex.
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- The Influence of Menopause and Inflammation on Redox Status and Bone Mineral Density in Patients with Rheumatoid Arthritis.Oxidative medicine and cellular longevity · 2021Article
- Estrogen receptor-dependent and independent roles of benzo[a]pyrene in Ishikawa cells.The Journal of endocrinology · 2020Article
- Influence of pubertal development on urinary oxidative stress biomarkers in adolescent girls in the New York LEGACY cohort.Free radical research · 2020Article
- Systemic Oxidative Stress Is Increased in Postmenopausal Women and Independently Associates with Homocysteine Levels.International journal of molecular sciences · 2020Article
- Effects of Benzophenone-3 and Propylparaben on Estrogen Receptor-Dependent R-Loops and DNA Damage in Breast Epithelial Cells and Mice.Environmental health perspectives · 2020Article
- Formation and Biological Targets of Quinones: Cytotoxic versus Cytoprotective Effects.Chemical research in toxicology · 2017Article
- Genotoxicity ofToxicology research · 2017Article
- Estrogen- and stress-induced DNA damage in breast cancer and chemoprevention with dietary flavonoid.Genes and environment : the official journal of the Japanese Environmental Mutagen Society · 2017Review
- Effects of Oxidative Stress and Testosterone on Pro-Inflammatory Signaling in a Female Rat Dopaminergic Neuronal Cell Line.Endocrinology · 2016Article
- Oxidative Stress: An Effective Prognostic Tool for an Early Detection of Cardiovascular Disease in Menopausal Women.Biochemistry research international · 2016Article
- Dietary γ-Tocopherol-Rich Mixture Inhibits Estrogen-Induced Mammary Tumorigenesis by Modulating Estrogen Metabolism, Antioxidant Response, and PPARγ.Cancer prevention research (Philadelphia, Pa.) · 2015Article
- Oxidant/antioxidant status, paraoxonase activity, and lipid profile in plasma of ovariectomized rats under the influence of estrogen, estrogen combined with progesterone, and genistein.Drug design, development and therapy · 2015Article
- SERMs attenuate estrogen-induced malignant transformation of human mammary epithelial cells by upregulating detoxification of oxidative metabolites.Cancer prevention research (Philadelphia, Pa.) · 2014Article
- The role of oxidative stress in menopause.Journal of mid-life health · 2013Review
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Abstract
Metabolic activation of estrogens to catechols and further oxidation to highly reactive o-quinones generates DNA damage including apurinic/apyrimidinic (AP) sites. 4-Hydroxyequilenin (4-OHEN) is the major catechol metabolite of equine estrogens present in estrogen replacement formulations, known to cause DNA strand breaks, oxidized bases, and stable and depurinating adducts. However, the direct formation of AP sites by 4-OHEN has not been characterized. In the present study, the induction of AP sites in vitro by 4-OHEN and the endogenous catechol estrogen metabolite, 4-hydroxyestrone (4-OHE), was examined by an aldehyde reactive probe assay. Both 4-OHEN and 4-OHE can significantly enhance the levels of AP sites in calf thymus DNA in the presence of the redox cycling agents, copper ion and NADPH. The B-ring unsaturated catechol 4-OHEN induced AP sites without added copper, whereas 4-OHE required copper. AP sites were also generated much more rapidly by 4-OHEN. For both catechol estrogens, the levels of AP sites correlated linearly with 8-oxo-dG levels, implying that depuriniation resulted from reactive oxygen species (ROS) rather than depurination of estrogen-DNA adducts. ROS modulators such as catalase, which scavenges hydrogen peroxide and a Cu(I) chelator, blocked the formation of AP sites. In MCF-7 breast cancer cells, 4-OHEN significantly enhanced the formation of AP sites with added NADH. In contrast, no significant induction of AP sites was detected in 4-OHE-treated cells. The greater redox activity of the equine catechol estrogen produces rapid oxidative DNA damage via ROS, which is enhanced by redox cycling agents and interestingly by NADPH-dependent quinone oxidoreductase.
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