MECHANISM OF BYSTANDER MUTAGENESIS

旁观者诱变机制

• 批准号: 7992114
• 负责人: Tom K. Hei
• 金额: $ 27.97万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7992114
• 关键词: Abdomen; Abdominal Cavity; Address; Animals; Apoptosis; Area; Bystander Effect; Cell Culture Techniques; Cell Nucleus; Cell physiology; Cells; Chest; Chromosome abnormality; Collaborations; Communication; Connexins; Control Animal; Cytoplasm; DNA; Data; Diagnostic radiologic examination; Dose; Embryo; Female; Fibroblasts; Gap Junctions; Gene Expression; Genes; Genetic; Genomic Instability; Genotype; Goals; Health; High Pressure Liquid Chromatography; Hour; Human; Hydrolysis; In Vitro; Incidence; Instruction; Ionizing radiation; Low Dose Radiation; Lung; Mammalian Cell; Mammary Gland Parenchyma; Mammary gland; Mediating; Mediator of activation protein; Mitochondria; Mitochondrial DNA; Modeling; Mus; Mutagenesis; Mutate; Mutation; NF-kappa B; Nuclear; Oxidative Stress Induction; PTGS2 gene; Patients; Play; Point Mutation; Population; Process; Proteins; Publishing; Radiation; Radiation therapy; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Risk Assessment; Roentgen Rays; Role; Sampling; Series; Signal Pathway; Signaling Molecule; Signaling Pathway Gene; Signaling Protein; Small Interfering RNA; Staging; Time; Tissue Stains; Tissues; Transgenic Mice; Transgenic Organisms; Universities; cancer risk; cellular targeting; cyclooxygenase 1; cyclooxygenase 2; human tissue; in vivo; irradiation; micronucleus; mitochondrial DNA mutation; novel; oxidative DNA damage; programs; response; theories

PROJECT SUMMARY (See instructions): Radiation induced bystander effects have been demonstrated with a variety of endpoints using mammalian cell cultures as well as 3D human tissues. However, neither the mechanism nor the relevance of the bystander response to human health is clear. While gap junction communication and presence of soluble mediator(s) are known to play an important role in the bystander response, the precise signaling molecules have yet to be identified. The overall goals of this project are to define the incidence and mechanism of radiation-induced bystander mutagenic response in vivo (non-targeted response); to clarify the role of cyclooxygenase-2(COX-2) signaling pathways in the process; and to examine the incidence of genomic instability in bystander tissues in wild type and in genetic susceptible animals. The central testable hypothesis is that COX-2 mediates radiation induced bystander mutagenesis in vivo and that the bystander cells are genomically unstable in ATM homozygously mutated animals. A series of five inter-related specific aims are proposed to address these goals. The novel gpt delta ttansgenic mice and embryo fibroblasts from these animals will be used to conelate the findings under both in vitro and in vivo conditions. A small 1 cm by 1 cm zone in the lower abdominal area will be inadiated with graded doses of X-rays and the expression of COX-2 levels as well as incidence and types of Spi (deletions) and gpt (point mutations) mutations will be examined in the non-targeted lung and breast tissues. Bystander response as a result of nuclei and cytoplasmic targeting in MEF cells from wild type and COX-2knock out mice will be conducted with a microbeam to delineate specific gene signaling pathways. To further define genomic instability in bystander tissues, incidence of gpt and Spi mutations will be examined over a period of several weeks post-irradiation in wild type as well as y47Mknock out mice. Extensive program interaction with Projects 1 and 3 are planned in that the role of Rad9 (Project 1) and the connexin protein (TCTP, Project 3) in modulating COX-2 function will be examined. Radiation induced bystander effects represent a paradigm shift in our understanding of the basic radiobiological principle and target theory of ionizing radiation. A better understanding of the mechanism of the bystander effect is important for an accurate assessment of cancer risk associated with low dose radiation exposure.

项目摘要（请参阅说明）： 使用哺乳动物细胞培养物以及3D人体组织，已经证明了辐射诱导的旁观者效应。但是，旁观者对人类健​​康的反应的机制和相关性都不明确。虽然已知间隙连接通信和可溶性介体的存在在旁观者的响应中起着重要作用，但精确的信号分子尚未确定。该项目的总体目标是定义体内辐射引起的旁观者诱变反应的发病率和机制（非靶向反应）；为了澄清过程中环氧合酶-2（COX-2）信号通路的作用；并检查野生型和遗传易感动物中旁观者组织中基因组不稳定性的发生率。中心可检验的假设是，COX-2介导了体内诱导的旁观者诱导的辐射诱导的诱因，并且旁观者细胞在ATM纯合突变的动物中基因组上不稳定。提出了一系列相互关联的特定目标来解决这些目标。来自这些动物的新型GPT DEDA TTANSGENIC小鼠和胚胎成纤维细胞将用于在体外和体内条件下连接发现。在下腹区域中，小1厘米乘1 cm的区域将被X射线级分，COX-2水平的表达以及SPI（缺失）和GPT（点突变）突变的发病率和类型将在非针对性的肺和乳房组织中检查。旁观者的反应是由野生型和Cox-2敲除小鼠的MEF细胞中的细胞核和细胞质靶向的结果，将使用微片进行描绘特定的基因信号传导途径。为了进一步定义旁观者组织中的基因组不稳定性，将在野生型和Y47MKNOCK OUT小鼠的几周内检查GPT和SPI突变的发生率。计划与项目1和项目3进行广泛的计划互动，因为将检查RAD9（项目1）的作用（项目1）和连接蛋白（TCTP，项目3）在调节COX-2功能中的作用。辐射诱导的旁观者效应代表了我们对基本放射生物学原理和电离辐射的靶标理论的理解。更好地理解旁观者效应的机制对于准确评估 与低剂量辐射暴露有关的癌症风险。