Werts E D, Gould M N
Carcinogenesis. 1986 Jul;7(7):1197-201. doi: 10.1093/carcin/7.7.1197.
Increasing evidence suggests a role for reactive free radical oxygen species in the multi-stage events of chemical carcinogenesis. We hypothesized that variations in the level of superoxide dismutase (SOD), a major endogenous antioxidant enzyme, may account in part for variations in susceptibility to cancer induced by polycyclic aromatic hydrocarbons (PAH). The SOD activity of mammary epithelial cells from rats with varying susceptibility to dimethylbenz[a]anthracene (DMBA)-induced breast cancer was assayed. Ageing, pregnancy and previous multiple pregnancies reduce susceptibility of Sprague--Dawley female rats to DMBA. These decreases in susceptibility were correlated with increased levels of SOD activity. Only minor differences in SOD activity was observed in mammary epithelium of genetic strains of rats with differences in susceptibility to DMBA. These data suggest that, in models where physiological differences may account for variations in effectiveness of PAH to induce mammary cancer, SOD activity is inversely correlated with breast cancer susceptibility and support the hypothesis that cancer susceptibility may be partially mediated through reactive free radical oxygen intermediates.
越来越多的证据表明，活性自由基氧物种在化学致癌作用的多阶段事件中发挥作用。我们推测，超氧化物歧化酶（SOD）作为一种主要的内源性抗氧化酶，其水平的变化可能部分解释了多环芳烃（PAH）诱导的癌症易感性差异。对二甲基苯并[a]蒽（DMBA）诱导的乳腺癌易感性不同的大鼠乳腺上皮细胞的SOD活性进行了测定。衰老、怀孕和既往多次怀孕会降低Sprague-Dawley雌性大鼠对DMBA的易感性。这些易感性的降低与SOD活性水平的升高相关。在对DMBA易感性不同的大鼠遗传品系的乳腺上皮中，仅观察到SOD活性的微小差异。这些数据表明，在生理差异可能解释PAH诱导乳腺癌有效性差异的模型中，SOD活性与乳腺癌易感性呈负相关，并支持癌症易感性可能部分通过活性自由基氧中间体介导的假说。
