DNA PK IN RADIATION DAMAGE REPAIR AND LYMPHOMAGENESIS

辐射损伤修复和淋巴生成中的 DNA PK

• 批准号: 2677318
• 负责人: GLORIA C LI
• 金额: $ 24.46万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 2003-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2677318
• 关键词: DNA damage; DNA repair; cell growth regulation; chromosome aberrations; enzyme complex; enzyme mechanism; gel electrophoresis; gene rearrangement; gene targeting; genetic crossing over; genetic recombination; genetically modified animals; immunogenetics; ionizing radiation; laboratory mouse; lymphocyte; lymphoma; neoplastic transformation; protein kinase; radiation carcinogenesis; radiation genetics; radiation related neoplasm /cancer; radiation sensitivity; tumor suppressor genes

DESCRIPTION: DNA-dependent protein kinase DNA-PK is a serine-threonine kinase that consists of a 465-kDA catalytic subunit, DNA-PKcs, and a 70 kDA and an 86-kDa heterodimeric DNA-targeting component, Ku70 and Ku80. Based on our recent pilot studies of Ku70- /- and Ku80-/- mice and earlier studies of SCID mice by others, it is postulated that each of the three components of DNA-PK may have distinct yet overlapping roles. The proposed studies aim at a test of this hypothesis and the elucidation of the physiological roles of the individual components of DNA-PK in DNA double- strand break (DSB) repair and V(D)J recombination, in lymphocyte development and lymphomagenesis. There are two specific aims. Specific Aim 1 focuses on the physiological role(s) of the individual subunits in DSB repair, V(D)J recombination and lymphocyte development. We plan to generate mutant mice and cell lines deficient in one or more of these polypeptides, and use them to deduce the roles of individual components of DNA-PK during T-and B-cell development, and in the repair of radiation-induced DSB and the associated effects on radiation sensitivity. In addition, we will examine the effect of low (non-lethal) does of ionizing radiation on V(D)J recombination in these mutant mice and evaluate whether T- and B-cell development can be restored by X- irradiation and whether such restoration enhances the development of lymphoma. Specific Aim II focuses on the role(s) of Ku70, Ku80 and DNA-PKcs in lymphomagenesis and tumorigenesis. We will test a hypothesis, inferred from our preliminary studies, that the loss of Ku70 enhances illegitimate recombination and leads to the development of lymphoma. Using various mutant mice and cell lines, spontaneous tumor development and tumor induction by ionizing radiation will be studied in vivo, and neoplastic transformation in vitro. In addition, the induction of chromosome damage (chromosome aberrations and sister chromatid exchanges) with and without X-irradiation will be examined with a view to understand the roles of the individual subunits of DNA-PK in the maintenance of genomic stability. The proposed study should add new information and insight regarding the physiological functions of DNA-PK and its individual subunits in programmed gene rearrangement and the maintenance of genomic stability. Furthermore, our studies should verify whether there is a role of Ku70 in lymphomagenesis, and specifically whether Ku70 may be considered as a candidate tumor suppressor gene.

描述：DNA 依赖性蛋白激酶 DNA-PK 是一种丝氨酸-苏氨酸 由 465-kDA 催化亚基、DNA-PKcs 和 70 kDA 和 86 kDa 异二聚体 DNA 靶向成分 Ku70 和 Ku80。 基于我们最近对 Ku70-/- 和 Ku80-/- 小鼠及早期的初步研究 其他人对 SCID 小鼠的研究，假设这三种小鼠中的每一种 DNA-PK 的组成部分可能具有不同但重叠的作用。拟议的 研究旨在检验这一假设并阐明 DNA-PK 各个成分在 DNA 双链中的生理作用 淋巴细胞中的链断裂 (DSB) 修复和 V(D)J 重组 发育和淋巴瘤发生。有两个具体目标。 具体目标 1 侧重于个人的生理角色 DSB 修复、V(D)J 重组和淋巴细胞发育中的亚基。我们 计划产生缺陷小鼠和细胞系中的一种或多种 这些多肽，并用它们来推断个体的作用 T 细胞和 B 细胞发育过程中以及修复过程中 DNA-PK 的组成部分 辐射引起的 DSB 及其对辐射敏感性的相关影响。 此外，我们将检查低（非致命）剂量的效果 电离辐射对这些突变小鼠 V(D)J 重组的影响 评估 X- 是否可以恢复 T 细胞和 B 细胞的发育 辐射以及这种恢复是否促进了发育 淋巴瘤。 具体目标 II 重点关注 Ku70、Ku80 和 DNA-PKcs 在 淋巴瘤发生和肿瘤发生。我们将检验一个假设，推断 从我们的初步研究来看，Ku70 的缺失增强了非法 重组并导致淋巴瘤的发展。使用各种 突变小鼠和细胞系、自发肿瘤发展和肿瘤 将在体内研究电离辐射诱导，以及肿瘤 体外转化。此外，诱导染色体损伤 （染色体畸变和姐妹染色单体交换）有或没有 将检查 X 射线，以了解 X 射线的作用 DNA-PK 的各个亚基在维持基因组稳定性中的作用。 拟议的研究应增加有关以下方面的新信息和见解： DNA-PK及其各个亚基的生理功能 程序化基因重排和基因组稳定性的维持。 此外，我们的研究应该验证 Ku70 是否在 淋巴瘤发生，特别是 Ku70 是否可以被视为 候选抑癌基因。