Analysis of the human DNA damageby antioxidants for evaluation of safety in cancer chemoprevention

分析抗氧化剂对人类 DNA 的损伤，以评估癌症化学预防的安全性

基本信息

批准号：
09670356
负责人：
MURATA Mariko
金额：
$ 1.92万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670356/
关键词：
cancer chemoprevention antioxidant DNA damage hydrogen peroxid copper ion prooxidat alpha-tocopherol vitamin A

项目摘要

As a method to evaluatesafety in cancer chemoprevention, we have investigated whether antioxidants have the ability of the human DNA damage, using human cultured cells and 32P-labeledisolated DNA fragnrents of the human p53 tumor suppressor gene and c-Ha-ras-l prctooncogene. For detection of ce1lularDN.A damage, human cultured celles were treated with antioxidants, and examined by the pulsed-field get electrophoresis method. As the result. celularDNA damage was detected by the treatment of vitamin A, retinal, alpha-tocopherol and quercetin. Furthermore. we measured 8-hydroxy deoxyguanosine (8-OH-dG) formation, which was an index to an oxidative DNA lesion, quaruitativelyby HPLC-ECD.lntracellu1ar8-OH-dG formation significantly increased in cells treated with vitamin A, retinal and N-acetylcysteine. For detection of damage to isolated DN.A, antioxidants were incubated with 32P-labled DNA fragment in the presence of metalions, and the autoradiogram was obtained. alpha-Tocopherol, vitamin A, retinal, quercetin and N-acetylcysceine caused site-specific DN,A-damage in the presence of Cm(II). Catalase and bathocuproine. a Cu(I)-specific chelaror. inhibited the Co(II)-mediated DNA damage, suggesting the involvement of H_2O_2 and Curl).The DNA cleavage was observed frequency at thymine and cytosine residues in the presence of Cu(II).So-called "antioxidants" act as antioxidants in some circumstances, but also act as prooxidants in other circumstances. In another word, antioxidants become to have ability of damaging DNA in some cases, although antioxidants protect from oxidative stress in other cases. These oxidative DNA damage could be responsible for initiation and/or tumor promotion the multi-stage of carcinogenesis. In is requested chat safety and efficacy should be estimated before recommending use of antioxidants for cancer chemopreventton.

作为评估癌症化学预防的方法，我们研究了抗氧化剂是否具有人类培养基细胞和32p标记的人p53肿瘤抑制基因和C-HA-HA-HA-HA-HA-RAS-L PRCTOONCOGEN的能力。为了检测Ce1lulardn.a损伤，用抗氧化剂处理人培养的细胞，并通过脉冲场获取电泳方法检查。结果。通过治疗维生素A，视网膜，α-生育酚和槲皮素来检测到Celulardna损伤。此外。我们测量了8-羟基脱氧鸟苷（8-OH-DG）的形成，这是氧化DNA损伤的指数，在用维生素A，视网膜和n-乙酰基囊中的维生素A，视网膜素和N-乙酰基囊中处理的细胞中，HPLC-ECD.LPLC-ECD.LNTRACELLU1AR8-OH-DG形成显着增加。为了检测对分离的DN.A的损伤，在金属存在的情况下，将抗氧化剂与32p具有DNA片段孵育，并获得了自显影图。 α-生育酚，维生素A，视网膜，槲皮素和N-乙酰偶联性在CM存在的情况下引起位点特异性DN，A-损伤（II）。过氧化氢酶和茶园。 Cu（i）特定的chelaror。抑制了CO（II）介导的DNA损伤，表明H_2O_2和卷曲的参与）。在甲状腺素和胞质残基的频率下观察到DNA裂解在CU（II）存在的情况下。SO被称为“抗氧化剂”的存在，在某些情况下是抗氧化剂，但在某些情况下也是其他情况下的抗氧化剂。在另一个词中，抗氧化剂在某些情况下具有破坏DNA的能力，尽管在其他情况下抗氧化剂可以防止氧化应激。这些氧化性DNA损伤可能导致癌的起始和/或肿瘤促进癌的多阶段。在建议将抗氧化剂用于癌症化学上，应估算聊天安全性。