Spatiotemporal Regulation of Chk1 in Cell Biology, Cancer Etiology and Therapy

Chk1 在细胞生物学、癌症病因学和治疗中的时空调控

基本信息

批准号：
8467694
负责人：
YOU-WEI ZHANG
金额：
$ 30.62万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-05-08 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8467694
关键词：
Attention Binding Binding Proteins Biochemical Biological Markers Breast Cancer Cell Camptothecin Cancer Etiology Cancer Patient Cancer cell line Cell Culture Techniques Cell Cycle Checkpoint Cell Line Cell Nucleus Cell Survival Cells Cellular biology Checkpoint kinase 1 Chemotherapy-Oncologic Procedure Chromatin Chromosomes Complex Cytoplasm DNA DNA Damage DNA Repair DNA-Binding Proteins Data Defect Development Diagnosis Disease Progression Embryonic Development Event Failure Goals Human Human Genome Immunohistochemistry In Vitro Knowledge Laboratories Laboratory Study Lead Leucine Life Light MCM2 gene Maintenance Malignant Neoplasms Measures Modeling Molecular Mutagenesis Nuclear Nuclear Export Pharmaceutical Preparations Phase Phosphorylation Process Progression-Free Survivals Proteins RNA Interference Recruitment Activity Regulation Research Resistance Role Signal Pathway Signal Transduction System Testing Tissues Xenograft procedure assault cancer cell cancer therapy cell killing chemotherapy effective therapy helicase insight mouse model mutant novel novel strategies repaired response spatiotemporal surveillance network transmission process triple-negative invasive breast carcinoma tumor tumor growth tumor initiation ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): DNA, the blueprint of life located inside our cells, is under continuous assault by both environmental and intracellular DNA damaging agents. If not corrected, these errors may lead to the development of cancer. Fortunately, cells have built up elegant DNA surveillance networks, termed cell cycle checkpoints, to detect and repair damaged DNA. Central to cell cycle checkpoints is a protein kinase, Chk1, which is essential for cell viability and mammalian embryonic development. Intriguingly, increasing evidence suggests that Chk1 may benefit tumor growth as well, as Chk1 expression is increased in malignant tumors and its level positively correlates with tumor grade. Most importantly, we recently showed that Chk1 is centrally involved in the resistance of cancer cells to chemotherapeutic drugs. These findings highlight the importance of Chk1 in cancer etiology and therapy. Therefore, a better understanding of Chk1 regulation not only provides insights the DNA damage response, but may also lead to the development of novel strategies in cancer therapy. Recent studies from this laboratory and others revealed an exciting spatiotemporal regulation model of Chk1, in which DNA damage induces phosphorylation and a rapid release of Chk1 from chromatin into the nucleus, and subsequently into the cytoplasm. Failure to undergo chromatin release of Chk1 impairs cell cycle checkpoints. On the other hand, cellular accumulation of active Chk1 proteins leads to the resistance of cancer cells to a clinically used chemotherapeutic drug, camptothecin (CPT). This is probably because Chk1-profient cells are better equipped to handle DNA damage induced by CPT. Thus, a general hypothesis is that the dynamic mobilization of Chk1 from one cellular compartment to another is crucial for the activation of cell cycle checkpoints in response to DNA damage, as well as for the chemotherapy response. In order to test this hypothesis, we first wish to understand the detailed molecular mechanisms underlying this chromatin->nucleus->cytoplasm mobilization of Chk1 in cells. We will first determine the factors that regulate chromatin association and disassociation of Chk1, a non-DNA binding protein (Aim 1). Second, we will define how Chk1 is exported from the nucleus to the cytoplasm (Aim 2). Further, we will interrogate the functional significance of the spatiotemporal regulation of Chk1. To do so, we will utilize a novel in vitro system established by this laboratory that highly recapitulates cell cycle checkpoints, as well as unique cell lines we generated with Chk1 mutant proteins specifically localized in a particular cellular compartment (Aim 2). Lastly, we will expand this study from a pure biochemical and molecular research into something that will offer novel insights into cancer etiology and chemotherapy through testing two hypotheses: one is that blocking the spatiotemporal mobilization of Chk1 sensitizes cancer cells to chemotherapeutic drugs, and the other is that Chk1 is a predictive marker for the therapy response of human tumors to chemotherapy (Aim 3).

描述（由申请人提供）：DNA 是我们细胞内生命的蓝图，不断受到环境和细胞内 DNA 损伤剂的攻击。如果不纠正，这些错误可能会导致癌症的发生。幸运的是，细胞已经建立了优雅的 DNA 监视网络，称为细胞周期检查点，用于检测和修复受损的 DNA。细胞周期检查点的核心是蛋白激酶 Chk1，它对于细胞活力和哺乳动物胚胎发育至关重要。有趣的是，越来越多的证据表明 Chk1 也可能有利于肿瘤生长，因为 Chk1 表达在恶性肿瘤中增加，并且其水平与肿瘤分级呈正相关。最重要的是，我们最近表明 Chk1 主要参与癌细胞对化疗药物的耐药性。这些发现强调了 Chk1 在癌症病因学和治疗中的重要性。因此，更好地了解 Chk1 调控不仅可以深入了解 DNA 损伤反应，还可能导致癌症治疗新策略的开发。该实验室和其他实验室的最新研究揭示了 Chk1 的令人兴奋的时空调控模型，其中 DNA 损伤诱导磷酸化，Chk1 从染色质快速释放到细胞核中，随后释放到细胞质中。 Chk1 染色质释放失败会损害细胞周期检查点。另一方面，活性 Chk1 蛋白的细胞积累导致癌细胞对临床使用的化疗药物喜树碱 (CPT) 产生耐药性。这可能是因为 Chk1 丰富的细胞能够更好地处理 CPT 引起的 DNA 损伤。因此，一个普遍的假设是，Chk1 从一个细胞区室到另一个细胞区室的动态动员对于响应 DNA 损伤而激活细胞周期检查点以及化疗反应至关重要。为了检验这一假设，我们首先希望了解细胞中 Chk1 从染色质->细胞核->细胞质动员的详细分子机制。我们将首先确定调节 Chk1（一种非 DNA 结合蛋白）染色质结合和解离的因素（目标 1）。其次，我们将定义 Chk1 如何从细胞核输出到细胞质（目标 2）。此外，我们将探讨 Chk1 时空调节的功能意义。为此，我们将利用该实验室建立的新型体外系统，该系统高度概括细胞周期检查点，以及我们用特定于特定细胞区室的 Chk1 突变蛋白生成的独特细胞系（目标 2）。最后，我们将把这项研究从纯粹的生化和分子研究扩展到通过测试两个假设来为癌症病因学和化疗提供新的见解：一个是阻断 Chk1 的时空动员使癌细胞对化疗药物敏感，另一个是阻止 Chk1 的时空动员使癌细胞对化疗药物敏感。 Chk1 是人类肿瘤对化疗的治疗反应的预测标记（目标 3）。