ABSTRACT
This chapter provides a brief overview of the formation of several reactive species and their relevance to skin cancer. Reactive oxygen species (ROS) contribute to the induction and/or development of many human diseases such as heart attack, stroke, inflammatory bowel disease, cancer, emphysema, and the hereditary diseases ataxia telangiectasia, Fanconi’s anemia, and Bloom syndrome. It is increasingly proposed that, along with ROS, another chemical class of reactive intermediates that may play a significant role in skin-related disorders is the reactive nitrogen species derived from nitric oxide. Skin cancer is a well-studied phenomenon in murine models consisting of three sequential steps: tumor initiation, promotion and progression. Tumor initiation is an irreversible and inheritable process characterized by the alteration/modification of DNA resulting in altered gene function and cell responsiveness and a selective clonal expansion advantage. Tumor promotion in mouse skin can be accomplished by repetitive treatment with tumor-promoting chemicals such as phorbol esters, benzoyl peroxide, and so on.
