Dynamics of Signaling Pathways: Mechanism and Function

项目摘要 我们的长期目标是了解生物信号的动态行为是如何被控制的，以及这些信号是如何被控制的。 动力学影响细胞反应。该建议侧重于p53的基本细胞机制， 信令网p53系统协调细胞对环境损伤的反应， 尤其是那些会破坏DNA的。p53系统的缺失或突变强烈倾向于 人类细胞的癌症，并在大部分癌症中观察到。虽然分子功能和 p53通路的调节已经被广泛研究，野生型或突变型p53 决定了单个细胞的命运，以及为什么暴露于相同损伤的细胞最终会有不同的命运， 是很难理解的。要回答这些问题，就需要对事件发生的顺序有一个定量的了解， 单个细胞和细胞背景（癌细胞和非癌细胞）之间的因果关系，p53 状态（野生型或突变型）、p53动力学和细胞结果（生长、停滞或死亡）。 在之前的资助期间，我们发现p53的时间动态（即p53水平的变化） 随着时间的推移）在细胞命运决定中发挥作用。不同的压力导致不同的p53动力学和调制， p53动力学改变细胞结果。此外，细胞间p53诱导率的差异解释了 因毒品引发的派系杀戮我们现在建议将p53的联合收割机定量动态测量 及其靶基因在单细胞中的表达，结合单细胞RNA-Seq和数学建模来确定 p53应答的异质性起源以及将p53动力学与 特定的表型结果。我们还将研究p53在不同癌症模型中的动力学， 物种和组织在体内，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节和功能，并确定治疗方法 这将提高放射治疗和化学治疗对具有特定突变的癌细胞的疗效。 我们的研究结果将为p53通路的控制和操纵提供新的见解，也许是最重要的。 保护人类细胞免受癌症发展的重要途径。我们预计详细的 定量了解p53回路，这一控制单个细胞生长或死亡的关键回路 细胞，将帮助我们理解为什么一些细胞在化疗药物的反应中死亡，而另一些细胞存活， 并可能提出新的策略来选择性地将癌细胞推向永久性停滞或死亡。它 此外，我们的研究将有助于预测特定药物对特定基因型肿瘤的影响， 为分析、描述和理解其他信令的动态提供原型 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.