Papel de las especies reactivas del oxígeno (ERO) en la carcinogenesis

Abstract

In aerobio llf'e, oxidative stress arise from both endogenous and exogenous sources. Despite antioxidant defense mechanisms, cell damage from oxygen free radicals (OFR), which include superoxide anion, hydrogen perox­ide and hydroxyl radical, is ubiquitous. OFR-related lesions that do not cause cell death can stimulate the development of several age-dependent pathologies such as atherosclerosis, arthritis, neurodegenerative disorders and cancer. This review discusses the effects of oxidative stress at different stages of carcino­genesis and the role of antioxidant enzymes and sorne nutrients in this microevolutive process that requires the cumulative action of multiple events. Mutagenesis through oxidative DNA damage is widely hypothesized to be a fre­quent event in the normal human cell. A large body of evidence suggests an important role of OFR in the expansion of tumor clones and acquisition of ma­hgnant properties, being considered a relevant class of carcinogens. In addi­tion, the use of immunohistochemical techniques has showed that all cancers examined to date manifest some imbalance in theirantioxidant mechanisms to respect the primary cell. In the near future new insights in cancer therapies, based on modulation of cellular redox state, may lead to a way to additional tools against carcinogenesis from OFR.