Role of oxidative DNA damage in cancer initiation and promotion.

摘要: Normal aerobic metabolism produces huge amounts of potentially dangerous oxidants, controlled by a variety antioxidant systems. An imbalance between the generated and exogenously inflicted oxidants oxidant system is termed oxidative stress. Even without stress, i.e. under normal physiological conditions, damage to vital cellular micromolecules, such as DNA, extensive, amounting hundreds hits per cell day. More than one hundred different modifications in DNA have been described. The hydroxylation guanine 8-position most frequent mutagenic lesion 8-hydroxylation leads lack base pairing specifically misreading modified adjacent residues. are so that extensive specific repair needed for survival. Indeed, multiple enzyme systems mediate remove/repair modification Within hot-spots subsequent mutation described, some specificity appears compared other agents can lead aflatoxin benzo[a]pyrene. Numerous publications from epidemiology intervention studies with antioxidants point at an important factor cancer development certain sites. Yet, direct evidence linking has not published. With regard antoxidant prevention no effective single substance far identified.