Oxidative stress and redox signaling in carcinogenesis

Carcinogenesis leads to a self-replicating transformed cell which conveys the generation of a larger number of cells with an increasing accumulation of abnormalities. Oxidative stress and reactive species (RS) participate at all stages of the malignancy/carcinogenic process aroused from both inherited and environmental factors. This chapter begins with a discussion on the redox environment and cancer. Next, it talks about the oxidative modifications to biomolecules and carcinogenesis and about the measurement of oxidative data damage in human cancer. Epigenetic involvement in oxidative stress-induced carcinogenesis is explained. The chapter concludes with a discussion on deregulation of cell death pathways by oxidative stress in cancer progression. Impairment and/or alteration of cell death pathways are a central element in cancer progression, and chemotherapeutic approaches involve either the depletion of antioxidant defenses in cancer cells or enhancement of oxidative damage in order to overcome anti-apoptotic defenses and activate cell death pathways.