Transcription Coupled DNA Repair and Human Disease

转录耦合 DNA 修复与人类疾病

• 批准号: 6620051
• 负责人: PHILIP COURTLAND HANAWALT
• 金额: $ 26.1万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-28 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6620051
• 关键词: DNA damage; DNA repair; benzopyrenediol epoxide; chemical carcinogenesis; congenital skin disorder; enzyme linked immunosorbent assay; genetic transcription; mutagens; neoplasm /cancer genetics; oxidative stress; radiation carcinogenesis; radiation genetics; radiation sensitivity; southern blotting; tissue /cell culture; ultraviolet radiation; western blottings

DESCRIPTION: (PROVIDED BY APPLICANT) This project is concerned with the molecular epidemiology of cancer. Many independent genetic events occur in the transformation from a normal cell to malignancy. Changes in genomic DNA occur at specific sites and can lead to activation of proto-oncogenes or inactivation of tumor suppressor genes through mutation, recombination, gene amplification, translocation, or other chromosomal abnormalities. In some human hereditary diseases, an increased incidence of neoplasia is correlated with a defect in the repair and/or replication of damaged DNA. Our ultimate objective is to understand how the processing of damaged DNA in mammalian cells relates to carcinogenesis. We are particularly interested in how human cells process DNA lesions through the respective pathways of global genomic excision repair (GGR) and transcription-coupled repair (TCR). While a deficiency in GGR is well-known to predispose to cancer, a defect in TCR, as in the hereditary disease Cockayne syndrome (CS), does not. The characteristic developmental and neurological problems in CS are thought to be a consequence of defective TCR of endogenous oxidative DNA damage. We have documented a TCR deficiency in "UV Sensitive syndrome" (UVSS), a hereditary disease that does not present the developmental/neurological features of CS. We propose to test our hypothesis that the UVSS gene product is essential for TCR through the nucleotide excision repair pathway but not through the base excision repair pathway that deals with oxidative DNA lesions. UVSS could be a key gene in the link between DNA repair and transcription. Our proposal includes the following sub-projects: (1) The role of TCR in repair of oxidative DNA lesions will be assessed in UVSS cells, using established methods for gene-specific repair. (2) Repair of other classes of DNA damage (e.g., Benzo[a]pyrene diol-epoxide) will be assessed, using monoclonal antibodies, 32P post-labeling, and gene specific repair assays, to further characterize the repair deficiency in UVSS cells. (3) Mutagenesis studies will be performed in UV-irradiated UVSS cells for comparison with those in CS. (4) The phenomenon of inhibited GGR in active or inactive genes in TCR-deficient cells will be further characterized. (5) A complementation assay will be used to characterize cells from photosensitive patients of unknown genotype, obtained from existing collections, for assignment to UVSS, CS, or other known or unknown syndromes. The results should enhance our understanding of the role of TCR in relation to human tumorigenesis and development. New genes implicated in TCR may be discovered. Novel interactions may be revealed that will clarify relationships between cellular DNA transactions.

描述：（由申请人提供）本项目涉及 癌症的分子流行病学许多独立的遗传事件发生在 从正常细胞到恶性细胞的转变。基因组DNA发生变化 在特定位点并可导致原癌基因激活或失活 通过突变、重组、基因扩增， 易位或其他染色体异常。在一些人类遗传性 疾病中，肿瘤发生率的增加与肿瘤的缺陷相关 修复和/或复制受损的DNA。我们的最终目标是 了解哺乳动物细胞中受损DNA的加工过程与 致癌作用我们对人类细胞如何处理DNA特别感兴趣 损伤通过各自的途径的全球基因组切除修复（GGR） 和转录偶联修复（TCR）。虽然GGR的缺陷是众所周知的， 易患癌症，TCR缺陷，如遗传性疾病Cockayne 综合征（CS），没有。典型的发育和神经系统 CS中的问题被认为是内源性TCR缺陷的结果。 氧化性DNA损伤我们已经记录了在“紫外线敏感”中TCR缺陷， 综合征”（UVSS），一种遗传性疾病， CS的发育/神经学特征。我们打算验证我们的假设 UVSS基因产物通过核苷酸切除对TCR是必需的 修复途径，但不通过碱基切除修复途径， DNA氧化损伤UVSS可能是DNA修复之间联系的关键基因 和转录。 我们的提案包括以下子项目： (1)TCR在氧化DNA损伤修复中的作用将在UVSS中评估。 细胞，使用已建立的基因特异性修复方法。 (2)修复其他类型的DNA损伤（例如，苯并[a]芘二醇-环氧化物） 将使用单克隆抗体、32 P后标记和基因 特异性修复测定，以进一步表征UVSS中的修复缺陷 细胞 (3)将在紫外线辐照的UVSS细胞中进行诱变研究， 与CS相比。 (4)GGR抑制的现象，在活跃或不活跃的基因， 将进一步表征TCR缺陷细胞。 (5)将使用互补测定来表征来自 基因型未知的光敏患者，从现有的 集合，用于分配给UVSS、CS或其他已知或未知的综合征。 这些结果应该能加强我们对TCR在以下方面的作用的理解： 人类肿瘤发生和发展。与TCR有关的新基因可能是 发现了新的相互作用可能会被揭示，这将澄清关系 细胞DNA交易之间的联系