Ultrasensitive and specific detection methods for exocylic DNA adducts: Markers for lipid peroxidation and oxidative stress
Ultrasensitive and specific detection methods for exocylic DNA adducts: Markers for lipid peroxidation and oxidative stress
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DOI：
10.1016/s0300-483x(00)00307-3
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发表时间：
2000-11-16
期刊：
影响因子：
4.5
通讯作者：
Nair, J
中科院分区：
文献类型：
--
作者：
Bartsch, H;Nair, J
在环外 DNA 加合物中，乙烯 (ε) 碱基（ε dA、ε dC、N-2,3-ε dG）是通过 DNA 碱基与源自内源性来源和致癌物质氯乙烯或氨基甲酸乙酯的脂质过氧化 (LPO) 产物反应生成的。最近发展的超灵敏方法使得在体内检测这些ε加合物并研究它们的形成以及在实验和人类致癌作用中的作用成为可能。促诱变的ε-DNA 修饰可以通过免疫亲和/P-32 后标记或免疫组织化学来检测。当从组织DNA中切除ε-加合物时，可以通过免疫亲和-HPLC-荧光方法对尿液中的修饰核苷进行定量。在未暴露的人类和啮齿动物的组织中检测到ε加合物的背景水平高度可变，这表明反式4-羟基-2-壬烯醛（通过其2,3-环氧化物）与DNA碱基的反应存在内源性形成途径。一些已知的癌症危险因素会增加这些 DNA 损伤的水平：在金属储存过量（血色素沉着病、威尔逊氏病）的患者的肝脏 DNA 中发现 epsilon 加合物升高，导致氧化应激和肝癌的高风险。炎症过程中产生的反应性 O/N-中间体，例如炎症性肠病 (IBD) 和家族性腺瘤性息肉病 (FAP) 患者，可能通过过氧亚硝酸盐介导的 LPO 和/或氧化花生四烯酸代谢增加，导致形成 ε 加合物 高 omega -6-多不饱和脂肪酸 (PUFA) 饮食增加 白细胞（WBC）中的ε-DNA加合物，特别是女性受试者（约40倍），而WBC-DNA脱氧鸟苷中的加合物丙二醛水平仅适度升高。总之，现在有越来越多的证据表明，在易患癌症的患者和啮齿类动物（肝脏、胰腺、结肠、皮肤）中，ε 加合物升高，这表明，当持续氧化应激形成促突变的ε加合物时，可以促使细胞发生恶性肿瘤。因此，环外 DNA 加合物的生物监测提供了有用的工具：（i）评估膳食脂肪、氧化应激和慢性炎症/感染过程的病因学贡献； (ii) 验证化学预防剂对内源性 DNA 损伤和癌症风险的功效； (iii) 深入了解氧化应激/LPO 衍生病变在人类癌症发生和进展中的作用。 (C) 2000 Elsevier Science Ireland Ltd. 保留所有权利。
Among exocyclic DNA adducts, etheno (epsilon) bases (epsilon dA, epsilon dC, N-2,3-epsilon dG) are generated by reactions of DNA bases with lipid peroxidation (LPO) products derived from endogenous sources and from the carcinogens vinyl chloride or urethane. The recent development of ultrasensitive methods has made it possible to detect these epsilon -adducts in vivo and to study their formation and role in experimental and human carcinogenesis. The promutagenic epsilon -DNA modifications call be detected by immunoaffinity/P-32-postlabelling or by immunohistochemistry. When epsilon -adducts are excised from tissue DNA, the modified nucleosides can be quantified in urine by an immunoaffinity-HPLC-fluorescence method. Highly variable background levels of epsilon -adducts were detected in tissues from unexposed humans and rodents, suggesting an endogenous pathway of formation from reaction of trans-4-hydroxy-2-nonenal (via its 2,3-epoxide) with DNA bases. Several known cancer risk factors increased the level of these DNA lesions: Elevated epsilon -adducts were found in hepatic DNA from patients with excess metal storage (haemochromatosis, Wilson's disease), resulting in oxidative stress and high risk of liver cancer. Reactive O/N-intermediates generated during inflammatory processes, for example in patients with inflammatory bowel disease (IBD) and familial adenomatous polyposis (FAP) led to the formation of epsilon -adducts likely through peroxynitrite-mediated LPO and/or increased oxidative arachidonic acid metabolism A high omega -6-polyunsaturated fatty acid (PUFA) diet increased epsilon -DNA adducts in white blood cells (WBC), particularly in female subjects (about 40-fold), while the level of adducted malondialdehyde in deoxyguanosine of WBC-DNA was only moderately elevated. In conclusion, there is now growing evidence that epsilon -adducts were elevated in cancer-prone patients and in rodents (liver, pancreas, colon, skin), suggesting that promutagenic epsilon -adducts, when formed as a consequence of persistent oxidative stress, can drive cells to malignancy. Therefore, biomonitoring of exocyclic DNA adducts offers useful tools: (i) to evaluate the etiological contributions of dietary fats, oxidative stress, and chronic inflammatory/infectious processes; (ii) to verify the efficacy of chemopreventive agents on endogenous DNA damage and cancer risk; and (iii) to gain mechanistic insights into the role of oxidative stress/LPO-derived lesions in the initiation and progression of human cancer. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.