Activation of Organic Hydroperoxide Tumor Promoters to Free Radicals in Target Cells

Although the molecular mechanisms involved in carcinogenesis are poorly understood at this time, intermediary events in the development of cancer have been described through the selective actions of discrete chemical agents (1). These processes have been studied in various model systems and have been termed initiation, promotion and progression (2). Initiation appears to involve the modification of cellular DNA, resulting in genotypically altered cells, while promotion encompasses a continuum of events allowing for the selection and clonal expansion of the initiated cells (3). Finally, progression completes the conversion of pre-malignant cells to malignant cells. Substantial evidence supports the involvement of free radical species, especially those derived from molecular oxygen, in multiple aspects of these processes (4).