Antioxidant enzyme levels in cancer.
Antioxidant enzyme levels in cancer.
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发表时间：
1997-04
影响因子：
2
通讯作者：
Oberley Td;Oberley Lw
中科院分区：
文献类型：
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作者：
Oberley Td;Oberley Lw
正常细胞受到抗氧化酶的保护，免受细胞代谢过程中产生的高浓度活性氧的毒性影响。尽管癌细胞产生活性氧，但生物化学已经证明，在大多数动物和人类癌症中，抗氧化酶水平很低。然而，已经发现一些癌症类型具有升高的抗氧化酶水平，特别是锰超氧化物歧化酶。动物和人类癌症的形态学研究已经证实，尽管来自几个器官系统的大多数肿瘤细胞类型具有低抗氧化酶，但腺癌可能具有升高的锰超氧化物歧化酶和过氧化氢酶水平。然而，迄今为止检查的所有癌症与起源细胞相比，抗氧化酶水平都有一些不平衡。抗氧化酶在癌症发生中的重要性难以使用生物化学技术在早期癌性病变中进行评估，因为这种病变很小，因此低于检测水平。使用免疫组织化学技术，人类和动物癌症的早期病变被证明具有低抗氧化酶，从而表明这些酶在癌症的发生和恶性表型中的作用。除了一种人类癌细胞类型（人类肾腺癌的颗粒细胞变体）外，所有检测的人类癌细胞类型都显示出低过氧化氢酶和谷胱甘肽过氧化物酶水平，这表明大多数癌细胞类型不能解毒过氧化氢。迄今为止，我们的研究结果用于提出基于细胞氧化还原状态调节的新癌症疗法。
: Normal cells are protected by antioxidant enzymes from the toxic effects of high concentrations of reactive oxygen species generated during cellular metabolism. Even though cancer cells generate reactive oxygen species, it has been demonstrated biochemically that antioxidant enzyme levels are low in most animal and human cancers. However, a few cancer types have been found to have elevated levels of antioxidant enzymes, particularly manganese superoxide dismutase. Morphologic studies of animal and human cancer have confirmed that although the majority of tumor cell types from several organ systems have low antioxidant enzymes, adenocarcinomas may have elevated manganese superoxide dismutase and catalase levels. However, all cancers examined to date have some imbalance in antioxidant enzyme levels compared with the cell of origin. Antioxidant enzyme importance in cancer genesis has been difficult to evaluate in early cancerous lesions using biochemical techniques because such lesions are small and therefore below the level of detection. Using immunohistochemical techniques, early lesions of human and animal cancers were demonstrated to have low antioxidant enzymes, thus suggesting a role for these enzymes both in the genesis of cancer and the malignant phenotype. All but one human cancer cell type (the granular cell variant of human renal adenocarcinoma) examined showed both low catalase and glutathione peroxidase levels, suggesting that most cancer cell types cannot detoxify hydrogen peroxide. Our results to date are used to propose new cancer therapies based on modulation of cellular redox state.