Study for mechanisms of reactive oxygen species related carcinogenesis

活性氧相关致癌机制研究

• 批准号: 09670358
• 负责人: TAKEUCHI Toru
• 金额: $ 2.05万
• 依托单位: Osaka 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-09670358/
• 关键词: Reactive oxygen species; oxidative DNA damage; mutation; carcinogenesis; hprt

Every life which depends on oxygen generates reactive oxygen species (ROS) in the body.ROS induce many kinds of damage, among which oxidative DNA damage is closely related to carcinogenesis.Oxidative DNA damage may induce mutations and the accumulation of the mutations may cause the cancer development.However no reports have described the mutagenicity and mutation spectra of randomly induced oxidative DNA damage in mammalian systems.In this study, using 8-hydroxydeoxyguanosine(8OHdG) as a marker of oxidative DNA damage, we evaluated the mutagenicity and mutation spectra of oxidative DNA damage in Chinese hamster V79 cell.Using a photo-Fenton reagent(NP-III) and UVA irradiation, we could induce considerable amounts of 8OHdG and DNA strand breaks in V79 cell.We then studied the mutant frequency in hypoxanthine-guanine phosphoribosyltransferase (hprt) locus by 6-thioguanine (6-TG) resistance.NP-III and UVA induced dose-dependent increase in both 8OHdG and mutant frequency, however, the in … More crease in 8OHdG was greater than that in mutant frequency.We collected 6-TG resistant clones and studied how their hprt gene had been mutated.We extracted DNA and mRNA from the clones and analyzed their genomic and complementary DNA of hprt.Most of the mutants showed deletion and 2-base exchange at T : A sites.From these results we conclude that randomly induced oxidative DNA damage may not be highly mutagenic at hprt locus and may induce mostly deletion type mutations.Oxidative DNA damage is considered highly mutagenic and 8OHdG is reported to induce G : C * T : A point mutation.These conclusion were drawn mainly from cell-free systems or bacteria with deficient to DNA repair enzymes.In our system 8OHdG was removed efficiently from the damaged DNA, thus oxidative DNA damage including 8OHdG might not induce mutant frequency and mutation spectra as expected.However, to draw a generalized conclusion in mammalian systems, we should study the effects of ROS on mutant frequency and mutation spectra in genes other than hprt. Less

每一个依赖氧的生命体都会在体内产生活性氧（reactive oxygen species，ROS），ROS可引起多种损伤，其中DNA氧化损伤与肿瘤的发生密切相关，DNA氧化损伤可诱发突变，突变的积累可导致肿瘤的发生。然而，在哺乳动物系统中随机诱导的DNA氧化损伤的致突变性和突变谱尚未见报道。本研究以DNA氧化损伤为研究对象，对DNA氧化损伤的致突变性和突变谱进行了研究。以8-羟基脱氧鸟苷（8-hydroxydeoxyguanosine，8 OHdG）作为DNA氧化损伤的标志物，研究了DNA氧化损伤对中国仓鼠V79细胞的致突变性和突变谱。结果表明，在V79细胞中，8 OHdG和DNA链断裂的发生率较高，而次黄嘌呤-鸟嘌呤磷酸核糖转移酶（hypoxanthine-guanine phosphoribosyltransferase，hprt）的突变频率较高。NP-III和UVA诱导8 OHdG和突变频率的剂量依赖性增加，然而， ...更多信息 我们收集了6-TG抗性克隆，研究了它们的hprt基因是如何发生突变的，提取了它们的DNA和mRNA，分析了它们的基因组DNA和互补DNA，发现大多数突变体在T：结果表明，随机诱导的DNA氧化损伤在hprt位点可能不是高度致突变性的，而可能诱导大多数缺失型突变，被认为具有高度致突变性，据报告，8 OHdG可诱导G：C * T：点突变。这些结论主要是从无细胞系统或缺乏DNA修复酶的细菌中得出的。在我们的系统中，8 OHdG被有效地从受损的DNA中去除，因此包括8 OHdG在内的氧化DNA损伤可能不会引起预期的突变频率和突变谱。然而，为了得出哺乳动物系统中的普遍结论，我们应该研究ROS对hprt以外基因突变频率和突变谱的影响。少

项目成果

Toru Takeuchi: "Mutagenicity of oxidative DNA damage in Chinese hamster V79 cell" Carcinogenesis. 18. 2051-2055 (1997)

Toru Takeuchi：“中国仓鼠 V79 细胞氧化 DNA 损伤的致突变性”致癌作用。

Mamoru Miyaguchi: "Correlation of epidennal growth factor receptor and radiosenistivity in human maxillary carcinoma cell lines" Acta Oto-Laryngologica. 118. 428-431 (1998)

Mamoru Miyaguchi：“人上颌癌细胞系表皮生长因子受体与放射敏感性的相关性”Acta Oto-Laryngologica。

Toru Takeuchi: "A human cell system for detecting asbestos cytogenotoxicity in vitro" Mutation Resarch. 438. 63-70 (1999)

Toru Takeuchi：“体外检测石棉细胞基因毒性的人体细胞系统”突变研究。

Mamoru Miyaguchi: "Correlation of epidermal growth factor receptor and radcosensitivity in human maxillary carcinoma cell Lines" Acta Oto-Laryngologica. 118. 428-431 (1998)

Mamoru Miyaguchi：“人上颌癌细胞系表皮生长因子受体与放射敏感性的相关性”Acta Oto-Laryngologica。

Mamoru Miyaguchi: "Correlation of epidermal growth factor receptor and radiosensitivity in human maxillary carcinoma cell Lines" Acta Oto-Lavyngologica. (in press).

Mamoru Miyaguchi：“人上颌癌细胞系表皮生长因子受体与放射敏感性的相关性”Acta Oto-Lavyngologica。