Dynamics of Signaling Pathways: Mechanism and Function

项目总结 我们的长期目标是了解生物信号的动态行为是如何控制的，以及如何 动力学会影响细胞的反应。这项建议集中在p53的基本细胞机制上。 信令网络。P53系统协调细胞对环境的侮辱和自发的反应 损害，特别是那些损害DNA的损害。P53系统的丢失或突变极易发生 人类细胞致癌，并在很大一部分癌症中观察到。而分子的功能和 对p53通路的调控已经进行了广泛的研究，野生型或突变型p53到底是如何 决定了单个细胞的命运，以及为什么暴露在相同侮辱下的细胞最终会有不同的命运， 人们对此知之甚少。回答这些问题需要对事件的顺序有定量的了解 单细胞与细胞背景(癌与非癌细胞)、P53的因果关系 状态(野生型或突变)、P53动态和细胞结果(生长、停滞或死亡)。 在上一个资助期/S我们发现P53的时间动态(即P53水平的变化 随着时间的推移)在细胞命运的决定中发挥作用。不同的胁迫导致不同的P53动态和调控 P53的动态改变了细胞的结果。此外，细胞间p53诱导率的差异解释了 针对毒品的派系杀戮。我们现在建议将p53的定量动态测量结合起来 以及其在单细胞中的靶基因，结合单细胞RNA-Seq和数学模型来确定 P53反应异质性的起源和将P53动态与转录级联联系起来 特定的表型结果。我们还将研究不同癌症模型中P53的动态变化， 并将寻找新的工具来扰乱P53的动态。我们的最终目标是 了解P53在不同遗传背景下的调控和功能，并确定治疗方法 这将提高对具有特定突变的癌细胞的放射和化疗效果。 我们的结果将为控制和操纵p53通路提供新的见解，可能是最 保护人类细胞免受癌症发展的重要途径。我们预计会有一份详细的 定量了解P53电路，这是控制单个细胞生长或死亡的关键电路 细胞，将帮助我们理解为什么一些细胞在化疗药物的作用下死亡，而另一些细胞存活， 并可能提出有选择地将癌细胞推向永久停滞或死亡的新策略。它 此外，我们的研究将有助于预测特定药物对具有特定基因类型的肿瘤的影响，并将 为分析、描述和理解其他信令的动态提供一个原型 人类细胞中的通路。

PROJECT SUMMARY Our long-term goal is to understand how the dynamic behavior of biological signals is controlled and how these dynamics affect cellular responses. This proposal focuses on fundamental cellular mechanisms of the p53 signaling network. The p53 system orchestrates cellular responses to environmental insult and spontaneous damage, particularly those that damage DNA. Loss or mutation of the p53 system strongly predisposes human cells to cancer, and is observed in a large fraction of cancers. While the molecular function and regulation of the p53 pathway have been extensively investigated, exactly how wild-type or mutant p53 determines the fate of individual cells, and why cells exposed to the same insult end up having different fates, is poorly understood. Answering these questions requires a quantitative understanding of the order of events in single cells and the causal relationships between cellular background (cancer and non-cancerous cells), p53 status (wild-type or mutated), p53 dynamics and cellular outcomes (growth, arrest or death). In the previous funding period/s we found that the temporal dynamics of p53 (i.e. changes in the levels of p53 over time) play a role in cell fate decisions. Different stresses lead to different p53 dynamics and modulation of p53 dynamics alters cellular outcomes. In addition, cell-to-cell variability in the rate of p53 induction explained factional killing in response to a drug. We now propose to combine quantitative dynamic measurements of p53 and its target genes in single cells, together with single cell RNA-Seq and mathematical modeling to determine the origin of heterogeneity in the p53 response and the transcriptional cascades that link p53 dynamics with specific phenotypic outcomes. We will also investigate the dynamics of p53 across different cancer models, species and tissues in vivo and will search for new tools to perturb p53 dynamics. Our ultimate goal is to understand the regulation and function of p53 under different genetic backgrounds and to identify treatments that will increase the efficacy of irradiation and chemotherapy for cancer cells with specific mutations. Our results will provide new insights into the control and manipulation of the p53 pathway, perhaps the most important pathway protecting human cells against the development of cancer. We anticipate that a detailed quantitative understanding of the p53 circuit, the key circuit controlling the decision to grow or die in single cells, will help us understand why some cells die in response to chemotherapeutic drugs while others survive, and may suggest novel strategies to selectively push cancer cells toward permanent arrest or death. It addition, our study will be help predict the effects of specific drugs on tumors with specific genotypes and will provide a prototype for the analysis, description, and understanding of the dynamics of other signaling pathways in human cells.