The Involvement of Peroxyl Free Radicals in Tumor Initiation and Promotion
In recent years, there has been considerable interest in the involvement of free radicals in carcinogenesis (1–4). Much of the research emphasis has focused on intermediates of oxygen reduction such as superoxide anion and hydroxyl radical (2). Organic analogs of superoxide anion and its protonated form, perhydroxyl radical, have received less attention but may be just as important biologically as reduced oxygen intermediates. Our laboratory is interested in the role of hydroperoxide-dependent oxidations in carcinogenesis and much of our research is concerned with the chemistry and biology of peroxyl radicals generated by metal-catalyzed fragmentations of unsaturated fatty acid hydroperoxides. We believe evidence exists to support the hypothesis that peroxyl free radicals contribute to metabolic activation of chemical carcinogens (e.g., polycyclic hydrocarbons) in the initiation phase of tumorigenesis; circumstantial evidence implicates peroxyl radicals in tumor promotion as well.
KeywordsRetinoic Acid Benzoyl Peroxide Tumor Promotion Mouse Skin Peroxyl Radical
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