DNA Double Strand Break Repair in Tobacco Carcinogenesis

烟草致癌过程中的 DNA 双链断裂修复

• 批准号: 6627743
• 负责人: JOEL S BEDFORD
• 金额: $ 7.25万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6627743
• 关键词: DNA damage; DNA repair; alveolar macrophages; benzopyrenes; cell death; cell population study; cell transformation; chemical carcinogenesis; chemical related neoplasm /cancer; chromosome aberrations; cytotoxicity; fluorescent in situ hybridization; gel electrophoresis; gene frequency; genetic susceptibility; immunocytochemistry; laboratory mouse; lung neoplasms; lymphocyte; nucleotides; protein kinase; respiratory disorder epidemiology; respiratory epithelium; smoking; tissue /cell culture; tobacco abuse

DESCRIPTION (provided by applicant): Despite strong epidemiological data associating tobacco smoke to lung cancer, the mechanism of carcinogenesis by tobacco chemicals is not well understood. Among those exposed to tobacco smoke, only a certain portion develop lung cancer suggesting the involvement of genetic factor(s) in the susceptible population. A difference in DNA repair ability has been suggested for the explanation of the susceptibility. Of the various DNA repair pathways, a relationship between nucleotide excision repair and tobacco carcinogens (e.g. benzo[a]pyrene) has been well documented. However, DNA double strand break (DSB) repair, another important repair pathway, has rarely been studied with tobacco chemicals in mammalian systems. Since a recent study revealed a positive association between lung cancer and the reduced activity of a protein involved in DNA DSB repair, this application is initiated to confirm and extend the study on the role of DNA DSB repair in tobacco carcinogenesis. DNA DSB is the most destructive form of DNA damage and can lead to cell death, mutation and transformation if not repaired or mis-repaired. An efficient way to study the role of DNA DSB repair is to use DNA DSB repair deficient mutant cell lines exposed to tobacco chemicals. Specific Aim 1 addresses: Various rodent and human DNA DSB repair deficient cell lines will be treated with several tobacco carcinogens and cigarette smoke condensate (CSC), and comparisons will be made to wild type cells with regard to cell survival and mutation frequency. This is to test the hypothesis "Mammalian cells utilize DNA DSB repair mechanism or protein(s) associated with DNA DSB repair in the recovery process of DNA damage induced by tobacco carcinogens". Further molecular studies are suggested based on the cell line studies. These studies have the potential to identify a new tobacco sensitive sub-population. The experiments in Specific Aim 2 are proposed based on our recent finding that lung cancer sensitive BALB/c mice showed a mild DNA DSB repair defect. Specific Aim 2 puts forward the studies on the cell viability, DNA DSB formation and chromosome rearrangements in alveolar macrophage (AM), lymphocytes and lung epithelial cells from BALB/c and C57BL/6 (control) mice exposed to tobacco carcinogens. Two hypotheses will be tested in this aim: (1) Cells from BALB/c mice show a higher level of chromosome misrejoining which is detected by a sensitive premature chromosome condensation (PCC) assay in interphase chromosomes combined with/without fluorescence in situ hybridization (FISH)." (2) There is a good correlation between the sensitivity data with lymphocytes and those with AM and/or lung epithelial cells. The proposed experiments not only provide new mechanistic insight on the initial step for tobacco carcinogenesis, but also help furnish sensitive diagnostic tools to identify lung cancer susceptible individuals.

描述（由申请人提供）： 尽管有大量流行病学数据将吸烟与肺癌联系起来， 烟草化学品致癌的机制还不十分清楚。 在那些暴露于烟草烟雾中的人中，只有一部分人会患上肺病。 癌症提示易感人群中遗传因素的参与 人口DNA修复能力的差异已经被认为是 解释易感性。在各种DNA修复途径中， 核苷酸切除修复与烟草致癌物（如烟草致癌物）之间的关系 苯并[a]芘）的情况已有很好的记录。然而，DNA双链断裂 (DSB)修复，另一个重要的修复途径，很少被研究， 哺乳动物系统中的烟草化学品。最近的一项研究显示， 肺癌与蛋白质活性降低之间的正相关 参与DNA DSB修复，启动本申请以确认 扩展了DNA双链断裂修复在烟草致癌过程中的作用研究。DNA DSB是最具破坏性的DNA损伤形式，可导致细胞死亡， 突变和转化，如果没有修复或错误修复。一种有效的方式 研究DNA DSB修复的作用是利用DNA DSB修复缺陷突变体， 暴露于烟草化学品的细胞系。具体目标1：各种 啮齿动物和人DNA DSB修复缺陷细胞系将用 几种烟草致癌物和香烟烟雾冷凝物（CSC），以及 将与野生型细胞在细胞存活方面进行比较， 突变频率这是为了验证“哺乳动物细胞利用 DNA DSB修复机制或与DNA DSB修复相关的蛋白质 烟草致癌物诱导的DNA损伤的恢复过程”。进一步 基于细胞系研究，建议进行分子研究。这些研究 有可能发现一个新的烟草敏感亚群。的 在具体目标2中的实验是基于我们最近的发现提出的， 肺癌敏感的BALB/c小鼠表现出轻微的DNA DSB修复缺陷。 具体目标2提出了对细胞活力、DNA DSB 肺泡巨噬细胞（AM）中的染色体形成和重排， BALB/c和C57 BL/6（对照）小鼠的淋巴细胞和肺上皮细胞 接触烟草致癌物。本文将检验两个假设：（1） 来自BALB/c小鼠的细胞显示出较高水平的染色体错连， 通过敏感的早熟染色体凝集（PCC）试验检测， 间期染色体原位结合/不结合荧光 杂交（FISH）。the results showed that the results of the test results were significantly higher than that of the test results.“ 淋巴细胞和AM和/或肺上皮细胞的数据。的 提出的实验不仅提供了新的机制的见解， 烟草致癌作用步骤，而且有助于提供敏感的诊断 用于识别肺癌易感个体的工具。

项目成果

Cytotoxicity of cigarette smoke condensate is not due to DNA double strand breaks: Comparative studies using radiosensitive mutant and wild-type CHO cells.

香烟烟雾冷凝物的细胞毒性不是由于 DNA 双链断裂：使用放射敏感性突变体和野生型 CHO 细胞的比较研究。

• DOI: 10.1080/09553000701481790
• 发表时间: 2007
• 期刊: International journal of radiation biology
• 影响因子: 2.6
• 作者: Kato,Takamitsu;Nagasawa,Hatsumi;Warner,Christy;Okayasu,Ryuichi;Bedford,JoelS
• 通讯作者: Bedford,JoelS