Nuclear Function of Abl in DNA Damage Response

Abl 在 DNA 损伤反应中的核功能

• 批准号: 7814434
• 负责人: JEAN Y.J. WANG
• 金额: $ 41.83万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7814434
• 关键词: Adverse effects; Alternative Splicing; Apoptotic; C-terminal; CD44 gene; Cancer cell line; Cell Death; Cells; Cessation of life; Chromosomes, Human, Pair 9; Cisplatin; Code; Complex; DNA Damage; Doxorubicin; Drug usage; Embryonic Development; Epitopes; Experimental Models; Functional RNA; Funding; Gene Cluster; Gene Expression; Gene Targeting; Genes; Genotoxic Stress; Goals; Human; Human Chromosomes; Human Genome; Ionizing radiation; Knowledge; Laboratories; Length; Light; Malignant Neoplasms; Malignant neoplasm of ovary; Mediating; MicroRNAs; Microprocessor; Mutagens; Mutate; Nuclear; Nucleotides; Pathway interactions; Phosphotyrosine; Polyadenylation; Process; Protein Tyrosine Kinase; Protein Tyrosine Phosphatase; Protein p53; Proteins; Public Health; RNA Polymerase II; Recovery; Recruitment Activity; Regulation; Research; Role; Signal Transduction; Signal Transduction Pathway; Terminal Repeat Sequences; Testing; Therapeutic; Transcript; Tyrosine; Tyrosine Phosphorylation; United States National Institutes of Health; cancer therapy; cell killing; chemotherapy; chromatin immunoprecipitation; improved; interest; killings; neoplastic cell; parent grant; pre-miRNA; pri-miRNA; protein function; research study; response; transcription factor; tumor

DESCRIPTION (provided by applicant): In March of 2009, NIH announced the availability of Recovery Act funds for competitive revision applications (NOT-OD-09-058). In response to that announcement, this application seeks to expand the scope of a project that is directed at understanding the role of nuclear Abl tyrosine kinase in DNA damage-induced cell death response. DNA damage inducers, i.e., genotoxins, are some of the most effective agents in cancer therapy. Therefore, fundamental understanding of genotoxin-induced cell death mechanisms holds the promise of enhancing the efficacy of cancer therapeutics. Studies from our laboratory have identified the nuclear Abl tyrosine kinase as an activator of cell death response to DNA damage. We have recently found that activation of Abl tyrosine kinase can regulate the expression of microRNAs. MicroRNAs are non-coding RNAs that are between 18~25 nucleotides in length. The human genome contains 500 to 600 miRNA genes, the expression of which is regulated during embryonic development, cellular differentiation and in response to genotoxic stress. Three miRNA genes are targets of regulation by the p53 tumor suppressor and they contribute to DNA damage-induced cell death. However, little is known of the mechanisms by which DNA damage regulates the expression of other miRNAs. The proposed study will fill this knowledge gap by pursuing the miRNA regulatory function of nuclear Abl. With the two-year funding from the Recovery Act, we will investigate the hypothesis that Abl phosphorylates the RNA polymerase II-CTD to recruit a nuclear Drosha-complex to stimulate the expression of specific miRNAs. We will (1) investigate the interactions of Abl, tyrosine phosphorylated RNA polymerase II and the Drosha-complex with the identified miRNA genes and their pri-miRNA transcripts and (2) determine the role of Abl-regulated miRNAs in DNA damage-induced cell death by focusing on the Eya1 and Eya3 transcription factors, as their miRNAs are predicted targets of an Abl-regulated miRNA, and they have recently been shown to antagonize the cell death response to DNA damage through their tyrosine phosphatase activity. The proposed research will investigate a previously unknown pathway that transduces DNA damage signals to the regulation of miRNA expression and cell death. Because Abl is not mutated in sporadic human cancers and because Abl can activate p53-independent cell death, results from the proposed research will shed light on how to exploit the pro-apoptotic miRNAs induced by DNA damage through Abl to kill tumor cells. PUBLIC HEALTH RELENVANCE: The proposed research will acquire fundamental knowledge on how DNA damage triggers cell death. In particular, this research will investigate a previously unknown effect of DNA damage inducing agents, e.g., ionizing radiation, cisplatin and doxorubicin, on the expression of microRNAs, which are non-coding RNAs that regulate the functions of protein-coding mRNAs. Results from this study will advance our understanding of cellular response to DNA damage and this knowledge will help to reduce the harmful side effects while improving the efficacy of cancer therapy.

描述（由申请人提供）：2009年3月，NIH宣布恢复法案基金可用于竞争性修订申请（NOT-OD-09-058）。为了回应这一声明，本申请旨在扩大一个项目的范围，该项目旨在了解核Abl酪氨酸激酶在DNA损伤诱导的细胞死亡反应中的作用。DNA损伤诱导剂，即基因毒素，是癌症治疗中最有效的药物之一。因此，对基因毒素诱导的细胞死亡机制的基本理解有望提高癌症治疗的疗效。我们实验室的研究已经确定了核Abl酪氨酸激酶作为DNA损伤细胞死亡反应的激活剂。我们最近发现，激活Abl酪氨酸激酶可以调节microrna的表达。MicroRNAs是长度在18~25个核苷酸之间的非编码rna。人类基因组包含500至600个miRNA基因，其表达在胚胎发育、细胞分化和基因毒性应激反应中受到调控。三个miRNA基因是p53肿瘤抑制因子调控的靶点，它们参与DNA损伤诱导的细胞死亡。然而，DNA损伤调节其他mirna表达的机制尚不清楚。本研究将通过研究核Abl的miRNA调控功能来填补这一知识空白。在复苏法案的两年资助下，我们将研究Abl磷酸化RNA聚合酶II-CTD以招募核drosha复合物来刺激特定mirna的表达的假设。我们将(1)研究Abl、酪氨酸磷酸化RNA聚合酶II和drosha复合物与鉴定的miRNA基因及其pri-miRNA转录物的相互作用；(2)通过关注Eya1和Eya3转录因子，确定Abl调控的miRNA在DNA损伤诱导的细胞死亡中的作用，因为它们的miRNA是Abl调控的miRNA的预测靶标。最近有研究表明，它们可以通过酪氨酸磷酸酶的活性来对抗细胞对DNA损伤的死亡反应。拟议的研究将探索一个以前未知的途径，将DNA损伤信号转导到miRNA表达和细胞死亡的调节。由于Abl在散发性人类癌症中不会发生突变，并且由于Abl可以激活p53非依赖性细胞死亡，因此拟议研究的结果将揭示如何利用Abl通过DNA损伤诱导的促凋亡mirna来杀死肿瘤细胞。