Building a Systems-Level View of Cell Cycle Checkpoints

构建细胞周期检查点的系统级视图

• 批准号: 7015372
• 负责人: JILL C SIBLE
• 金额: $ 22.28万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-06 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7015372
• 关键词: DNA damage; DNA replication; Xenopus oocyte; biological signal transduction; cell cycle; cell free system; cell growth regulation; developmental genetics; gene mutation; genetic regulation; mathematical model; model design /development; molecular biology information system; neoplastic cell; nonmammalian vertebrate embryology; protein kinase

DESCRIPTION (provided by applicant): Because the cell cycle underlies the growth and development of all eukaryotes, and misregulation of the cell cycle typifies cancers, achieving a systems-level understanding of how the cell cycle is controlled ranks among the most important goals in modern cell biology. Pairing experimental biology with mathematical modeling in a highly interactive collaboration creates a powerful approach to develop a comprehensive understanding of cell cycle control. This approach was used to discover that mitotic transitions are regulated by hysteresis and bistability. The next goal is to build on this foundation by addressing a critical issue: how the cell cycle engine is affected by external events, in particular, those events that threaten the integrity of the genome. Checkpoints arrest the cell cycle when a threat to genomic stability, such as unreplicated or damaged DMA, exists. Loss of checkpoint control characterizes nearly all cancer cells. Checkpoints will be investigated in the experimentally tractable cell-free extracts derived from eggs of Xenopus laevis and in Xenopus embryos, where the cell cycle extensively remodels during early development. To build this understanding, a mathematical model of the DNA replication checkpoint will be constructed and subjected to rigorous experimental testing. This model should reveal underlying dynamical controls and serve as a powerful tool for predicting the effect of pathologic and pharmacologic perturbations upon cell cycle checkpoints. To reach the goal of constructing a systems-level view of the DNA replication checkpoint, the following specific aims will be completed: 1) A mathematical model representing the effect of unreplicated DNA on the core cell cycle engine will be constructed, parameters will be optimized, and the model will be made available for public use on the World Wide Web. 2) Concurrently, key quantitative experiments concerning how nuclear concentration and cell cycle enzymes impact the DNA replication checkpoint will be conducted and data used to inform the model. 3) Once this fundamental view of how unreplicated DNA affects the cell cycle engine is in hand, the model will be extended to include the Chk1 kinase signaling pathway, a key potential target for cancer chemotherapeutics. 4) Finally, the model will be challenged to accurately represent three distinct behaviors of the DNA replication checkpoint during early development, providing a physiologic test case for the model and informing where additional data are needed.

描述（由申请人提供）：由于细胞周期是所有真核生物生长和发育的基础，而细胞周期的失调是癌症的典型特征，因此对细胞周期如何控制进行系统层面的理解是现代医学中最重要的目标之一。细胞生物学。在高度互动的协作中将实验生物学与数学模型结合起来，创建了一种强大的方法来全面了解细胞周期控制。这种方法用于发现有丝分裂转变受到滞后和双稳态的调节。下一个目标是在此基础上解决一个关键问题：细胞周期引擎如何受到外部事件的影响，特别是那些威胁基因组完整性的事件。当存在对基因组稳定性的威胁（例如未复制或损坏的 DMA）时，检查点会阻止细胞周期。失去检查点控制是几乎所有癌细胞的特征。将在从非洲爪蟾卵和非洲爪蟾胚胎中提取的实验上易处理的无细胞提取物中研究检查点，其中细胞周期在早期发育过程中广泛重塑。为了建立这种理解，将构建 DNA 复制检查点的数学模型并进行严格的实验测试。该模型应揭示潜在的动态控制，并作为预测病理和药理扰动对细胞周期检查点的影响的强大工具。为了达到构建DNA复制检查点的系统级视图的目标，将完成以下具体目标：1）构建代表未复制DNA对核心细胞周期引擎影响的数学模型，并优化参数，该模型将在万维网上供公众使用。 2) 同时，将进行关于核浓度和细胞周期酶如何影响 DNA 复制检查点的关键定量实验，并使用数据为模型提供信息。 3) 一旦掌握了关于未复制的DNA如何影响细胞周期引擎的基本观点，该模型将扩展到包括Chk1激酶信号通路，这是癌症化疗的一个关键潜在靶点。 4) 最后，模型将面临在早期开发过程中准确表示 DNA 复制检查点的三种不同行为的挑战，为模型提供生理测试用例并告知哪里需要额外的数据。