Transcription Coupled DNA Repair and Human Disease

转录耦合 DNA 修复与人类疾病

• 批准号: 6426802
• 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/6426802
• 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）该项目涉及 癌症的分子流行病学。许多独立的遗传事件发生在 从正常细胞向恶性肿瘤的转变。基因组 DNA 发生变化 在特定位点，可导致原癌基因激活或失活 通过突变、重组、基因扩增来抑制肿瘤抑制基因， 易位或其他染色体异常。在某些人类遗传 疾病，肿瘤发生率的增加与缺陷相关 受损 DNA 的修复和/或复制。我们的最终目标是 了解哺乳动物细胞中受损 DNA 的加工与 致癌作用。我们对人类细胞如何处理 DNA 特别感兴趣 通过全局基因组切除修复（GGR）的各个途径来修复病变 和转录偶联修复（TCR）。虽然 GGR 缺乏是众所周知的 易患癌症（TCR 缺陷），如遗传性疾病 Cockayne 综合征（CS），则不然。发育和神经学特征 CS 中的问题被认为是内源性 TCR 缺陷的结果 DNA 氧化损伤。我们已记录了“UV 敏感”中的 TCR 缺陷 综合症”（UVSS），一种遗传性疾病，不存在 CS 的发育/神经学特征。我们建议检验我们的假设 UVSS 基因产物通过核苷酸切除对于 TCR 至关重要 修复途径，但不通过碱基切除修复途径处理 DNA 氧化损伤。 UVSS可能是DNA修复之间联系的关键基因 和转录。 我们的建议包括以下子项目： (1) UVSS中将评估TCR在修复氧化DNA损伤中的作用 细胞，使用已建立的基因特异性修复方法。 (2) 修复其他类别的 DNA 损伤（例如苯并[a]芘二醇-环氧化物） 将使用单克隆抗体、32P 后标记和基因进行评估 特定的修复测定，以进一步表征 UVSS 中的修复缺陷 细胞。 (3) 将在紫外线照射的 UVSS 细胞中进行诱变研究 与CS中的比较。 (4) 活性或失活基因中GGR受到抑制的现象 TCR 缺陷细胞将被进一步表征。 (5) 互补分析将用于表征来自 未知基因型的光敏患者，从现有的 集合，用于分配给 UVSS、CS 或其他已知或未知的综合症。 这些结果应该会增强我们对 TCR 在以下方面的作用的理解： 人类肿瘤的发生和发展。与 TCR 相关的新基因可能是 发现了。可能会揭示新奇的互动，从而澄清关系 细胞 DNA 交易之间。