CELL SITE SPECIFIC MICROBEAM IRRADIATION AND RESPONSES

描述：研究目标是为了了解 识别和处理辐射引起的损伤， 强调染色体畸变的形成。 核DNA变化 显著影响人类健康，与细胞死亡有明显关系， 突变和致癌变化。 然而，对于 非核靶中诱发应力对长寿命核聚变的潜在贡献 术语有害影响。 很明显， 膜、细胞质和细胞核有助于损伤识别、信号传导 和反应途径。 p53分子是一种通路成分， 在广泛的细胞控制反应中，在突变或废除的 形式涉及许多人类癌症。 对《公约》作用的理解 可以有效地获得辐射响应中的亚细胞成分， 通过使用微束。 高LET电荷粒子的定向束可以 在亚细胞微团中引发显著水平的损害， 单细胞显微镜检查可能定位基因产物 到这些亚细胞区域。 在本提案中，我们将使用小区站点 具体的微束照射问的问题：可以非核 辐射引发染色体断裂反应或细胞周期延迟 p53的表达和定位。 p53的动力学是什么 回应？ 受辐射的细胞能在未受辐射的细胞中引发反应吗？ 邻居？ （用微束唯一可实现的）。 人类起源的细胞， 正常和突变型（ATM），以及表达野生型和突变型p53的细胞 这些研究中将使用构建体。 基于染色体畸变 形成动力学，假设p53不参与初始的 DNA损伤检测和修复，但它是一个监视组件，有助于 确保基因组的完整性。 这些基于微束的研究将有助于 提供一个时空框架，用于识别和解决 辐射引起的损伤和分子成分。

DESCRIPTION: Research objectives are directed toward understanding the recognition and processing of radiation induced lesions with a particular emphasis on the formation of chromosomal aberrations. Nuclear DNA changes significantly impact human health with clear relationships to cell death, mutation and oncogenic change. There is uncertainly however as to the potentia contributions of stresses induced in non-nuclear targets to long term deleterious effects. It is clear that molecular interplay between membrane, cytoplasm and nucleus contributes to damage recognition, signaling and respons pathways. The p53 molecule is one pathway component implicated in a broad rang of cellular control responses and in a mutated or abrogated form is involved i many human cancers. An understanding of the role of sub-cellular components in radiation responses can efficiently be obtained by use of a microbeam. A directed beam of high LET charges particles can initiate significant levels of damage in sub-cellular microbolumes and single cell microscopic examination ca potentially localize gene product/s to such sub-cellular regions. In this proposal we will use cell site specific microbeam irradiation to ask the questions: Can non-nuclear irradiation initiate chromosomal clastogenic responses or cell cycle delay and p53 expression and localization. What is the kinetics of a p53 response? Can irradiated cells initiate responses in unirradiated neighbors? (uniquely achievable with a microbeam). Cells of human origin, normal and mutant (ATM), and cells expressing wild type and mutant p53 constructs will be used in these studies. Based on chromosomal aberration formation kinetics, it is hypothesized that p53 is not involved in initial DNA damage sensing and repair but is a surveillance component that helps to ensure genomic integrity. These microbeam based studies will help to provide a spatio-temporal framework for the recognition and resolution of radiation induced damage and the molecular components.