BYSTANDER EFFECTS AND X RAY INDUCED GENOMIC INSTABILITY

旁观者效应和 X 射线引起的基因组不稳定性

• 批准号: 6628427
• 负责人: William F Morgan
• 金额: $ 25.1万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-15 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6628427
• 关键词: MCF7 cell; X ray; affinity chromatography; chromosome aberrations; free radical oxygen; gel filtration chromatography; gene mutation; radiation genetics; radiation sensitivity; stress proteins

DESCRIPTION:A basic paradigm in radiobiology is that following cellular exposure to ionizing radiation it is the deposition of energy in the cell nucleus that is responsible for its deleterious biological effects, and that DNA is the principal target for radiation damage. Two rapidly expanding fields of research, radiation-induced genomic instability and bystander effects (BSEs) have caused us to reevaluate this central dogma. In this application we will investigate the role of BSEs, i.e., those effects occurring in cells that were not irradiated, but were bystanders at the time of irradiation, in contributing to the deleterious effects of radiation exposure. We propose that some bystander effect factor (BSEF) is stimulated by cellular irradiation and secreted into the culture medium. We hypothesize that this BSEF is a protein to protein complex. The BSEF could itself be responsible for the observed BSEs in non-irradiated cells and/or could generate reactive oxygen species (ROS) and act in conjunction with these ROS to elicit BSEs. In turn these ROS could stimulate BSEF creating cycles of BSEF/ROS/BSEF/ROS, thus perpetuating a source of damage over time to account for the observed detrimental effects of X-irradiation. These hypotheses will be best addressed in 3 specific aims: Specific aim 1 will test the hypothesis that the SBEF can mimic the deleterious effects of X-ray exposure in non-irradiated cells. Specific aim 2 will test the hypothesis that our unique collection of chromosomally unstable cloned can produce "instability" factor(s) that can induce cytogenetic damage and genomic instability in non-irradiated cells. Specific aim 3 is to isolate, purify, and identify the factor(s) responsible for the BSE, and those "instability" factors produced by unstable cells. We are uniquely qualified to do this. We have in hand the assays for potential BSEs, radiation-induced genomic instability, and a collection of well-characterized chromosomally unstable clones of cells. We have experience in isolating, purifying, and identifying potential BSEF(s) and have the methodology to test candidates. Identifying the BSEF would enhance our understanding of how radiation exerts its deleterious effects and could directly impact risk estimation for radiation exposure.

描述：放射生物学中的一个基本范例是以下细胞 暴露在电离辐射中它是能量在细胞中的沉积 对其有害的生物效应负责的核，以及 DNA是辐射损伤的主要目标。两个快速扩张的油田 辐射诱导的基因组不稳定性和旁观者效应(BSES) 促使我们重新评估这一中心教条。在此应用程序中，我们将 研究BSES的作用，即那些发生在细胞中的效应 没有受到辐射，但在辐射时是旁观者，在 对辐射暴露的有害影响。我们建议一些人 旁观者效应因子(BSEF)受细胞辐射和 分泌到培养基中。我们假设这个BSEF是一种蛋白质 蛋白质复合体。BSEF本身可能对观测到的BSE负责 未受辐射的细胞和/或可产生活性氧物种(ROS)和 与这些RO一起行动，以获得BSE。反过来，这些RO可能 刺激BSEF创建BSEF/ROS/BSEF/ROS循环，从而使来源永久化 随着时间推移的损害，以说明观察到的有害影响 X射线照射。这些假设将在三个具体目标中得到最好的解决： 具体目标1将检验SBEF可以模拟有害的假设 X射线照射对未受照射细胞的影响。《特定目标2》将测试 假设我们独一无二的染色体不稳定克隆人可以 产生可引起细胞遗传损伤和基因组的不稳定因子(S) 未辐照细胞中的不稳定性。具体目标3是分离、纯化和 找出导致疯牛病的因素(S)，以及那些“不稳定”因素 由不稳定的细胞产生。 我们是唯一有资格这样做的人。我们手头有潜力的化验报告 BSES，辐射诱导的基因组不稳定性，以及一系列 特征明确的染色体不稳定的细胞克隆。我们有经验 在分离、纯化和鉴定潜在的BSEF(S)中，并具有 测试考生的方法。确定BSEF将加强我们的 了解辐射如何发挥其有害影响，并可能 直接影响辐射暴露的风险评估。