Mechanistic Studies of Nucleic Acid Damage and Their Application

描述(申请人提供)：这项研究的长期目标是了解核酸是如何被氧化损伤的，并利用这一知识来设计新的候选治疗方法和研究工具。核酸氧化在疾病的病因和治疗中起着重要的作用。例如，电离辐射会导致癌症，并通过破坏DNA来摧毁肿瘤细胞。核酸氧化也是一种重要的生物技术工具。例如，羟基自由基裂解有助于确定RNA结构和折叠动力学，以及确定核酸结合作用；这些研究将使用合成和物理有机化学、生物化学以及分子和细胞生物学来完成。我们采取的是一种互补的双重实验方法。我们通过设计分子来研究反应机理，这些分子使我们能够在寡核苷酸的特定位置独立产生活性中间体。此外，当我们的机制研究提供适当的动力时，我们就会合成利用这些发现的分子。建议的研究包括以下目标：1.在体外和细胞内设计和研究产生DNA链间交联物的基于机制的放射增敏剂。2.确定一个新的链间交联链家族在体外和在大肠杆菌中的修复情况。3.检测DNA中C5‘-氢原子抽提产生的自由基的反应性。这种自由基是由多种抗肿瘤药物产生的，是与羟基自由基反应产生裂解的主要来源。4.探索RNA中的碱基加合物产生直接链断裂的能力。5.设计分子，利用DNA中的电子转移作为产生链间交联链的手段。与公众健康相关：氧化核酸损伤在衰老以及癌症等遗传性疾病的病因和治疗中发挥着重要作用。核酸氧化也是生物技术中的一种宝贵的研究工具(例如，探测核酸结构和折叠动力学)，而这反过来又被用于研究人类疾病。因此，这项基础性研究对于了解癌症等疾病的病因和治疗具有重要价值。此外，从这项研究中收集到的知识的应用为潜在的新疗法和研究工具提供了起点。

DESCRIPTION (provided by applicant): The long term goal of this research is to understand how nucleic acids are oxidatively damaged, and to use this knowledge to design new therapeutic candidates and research tools. Nucleic acid oxidation is important in the etiology and treatment of disease. For instance, ionizing radiation causes cancer and destroys tumor cells by damaging DNA. Nucleic acid oxidation is also an important biotechnology tool. For instance, hydroxyl radical cleavage is useful for determining RNA structure and folding dynamics, as well as for determining nucleic acid binding interactions; These studies will be accomplished using synthetic and physical organic chemistry, biochemistry, as well as molecular and cellular biology. We pursue a complementary two-fold experimental approach. We study reaction mechanism by designing molecules that enable us to independently generate reactive intermediates at defined sites in oligonucleotides. In addition, when our mechanistic studies provide the appropriate impetus, we synthesize molecules that capitalize upon these discoveries. The proposed research encompasses the following goals: 1. Design and study in vitro and in cells of mechanism-based radiosensitizing agents that produce DNA interstrand cross-links. 2. Determine the repair of a novel family of interstrand cross-links in vitro and in E. coli. 3. Examine the reactivity of the radical resulting from C5'-hydrogen atom abstraction in DNA. This radical is produced by a variety of antitumor agents and is a major source of cleavage resulting from reaction with hydroxyl radical. 4. Explore the ability of nucleobase radical adducts in RNA to produce direct strand breaks. 5. Design molecules that will exploit electron transfer in DNA as a means for producing interstrand cross- links. Relevance to public health: Oxidative nucleic acid damage plays an important role in aging, as well as the etiology and treatment of genetic diseases, such as cancer. Nucleic acid oxidation is also an invaluable research tool in biotechnology (e.g. probing nucleic acid structure and folding dynamics), which is in turn used to study human disease. Hence, this fundamental research is valuable to understanding the etiology and treatment of diseases such as cancer. Furthermore, the application of the knowledge gleaned from this research provides the starting point for potentially new therapeutics and research tools.