Mapping the indirect p53 gene regulatory network

转录因子p53作为肿瘤进展的中心抑制因子。它通过调节大量的靶基因来控制细胞增殖和凋亡。然而，目前尚不清楚p53如何调节其许多靶基因，除了p53本身之外，还有哪些因素是上调或下调所必需的，以及它们的调节对正常细胞或癌细胞有什么贡献。我们的p53依赖的基因调控的分子基础的不完整的图片仍然是一个关键的差距，我们的整体理解肿瘤suppressing.I建议，在p53基因调控网络的几个途径贡献独立的，独特的和必要的基因调控活动响应p53激活。为了确定介导p53依赖性基因调控的新因子，我将采用我早先开发的一种新的荟萃分析方法。基于这种方法，我确定了一个潜在的p53-p21依赖性开关从MYC-MAX到MAD-MAX启动子占用。为了剖析转录因子介导p53依赖性基因调控的分子机制，我们将使用生物化学和遗传学方法。这个建议的目标是区分特定的调节器，介导p53依赖的转录调控的贡献，并确定其在肿瘤suppressing.Aim 1的作用：为了确定候选转录因子，如MYC/MAD/MAX，对p53依赖的基因调控的影响，我们将采用双重的方法。我们将确定高置信度的目标基因的荟萃分析和进行实验，以确定不同的转录因子结合的影响，特定的启动子元件的要求和细胞responsibility.Aim 2的变化：为了系统地确定其他候选人，我将采用我的荟萃分析方法和测试什么因素是丰富的结合p53调节基因的DREAM和p53的结合。此外，鉴于小鼠模型在弥合基础研究和临床研究之间的差距中的重要作用，我将确定介导人类和小鼠之间间接p53依赖性基因调控的候选途径的保守性。我将确定高置信度的目标基因图谱，并确定人类和小鼠基因列表之间的重叠和差异。总之，这些结果将提供一个更好的了解如何多个途径协同工作，以介导p53依赖的基因regulation.This应用程序旨在挑战和改变目前的范式，形成我们的理解的基础上p53信号通路在生长抑制。一个详细的p53依赖的转录调控的分子概况将开发和干扰间接调节的后果将被确定。实现这一目标的建议将澄清哪些因素介导p53依赖的基因调控，以及它们如何有助于肿瘤抑制。了解p53如何抑制肿瘤进展可能会发现新的治疗靶点来控制细胞生长。

The transcription factor p53 serves as a central suppressor of tumor progression. It controls cell proliferation and apoptosis by regulating a plethora of target genes. However, it is not clear how p53 regulates many of its target genes, what factors besides p53 itself are necessary for up or downregulation and what their regulation contributes to a normal or cancer cell. Our incomplete picture of the molecular basis of p53-dependent gene regulation remains a critical gap to our overall understanding of tumor suppression.I propose that several pathways in the p53 gene regulatory network contribute independent, distinct and essential gene regulatory activities in response to p53 activation. To identify novel factors that mediate p53-dependent gene regulation, I will employ a novel meta-analysis approach that I developed earlier. Based on this approach, I identified a potential p53-p21-dependent switch from MYC-MAX to MAD-MAX promoter occupancy. To dissect the molecular mechanisms by which the transcription factors mediate p53-dependent gene regulation, we will use biochemical and genetic approaches. The goals of this proposal are to distinguish contributions of specific regulators that mediate p53-dependent transcriptional regulation and to determine their roles in tumor suppression.Aim 1: To determine the impact of candidate transcription factors, such as MYC/MAD/MAX, on p53-dependent gene regulation, we will employ a dual approach. We will identify high confidence target genes with the meta-analysis and perform experiments to determine the impact of differential transcription factor binding, the requirement for specific promoter elements and changes in cellular response.Aim 2: To systematically identify additional candidates, I will employ my meta-analysis approach and test what factors are enriched for binding p53 regulated genes independent of DREAM and p53 binding. Moreover, given the important role of mouse models in bridging the gap between basic and clinical research, I will determine conservation of candidate pathways mediating indirect p53-dependent gene regulation between human and mouse. I will identify high confidence target gene maps and determine overlaps and differences between the human and mouse gene lists. Together, the results will provide a better understanding on how multiple pathways work in concert to mediate p53-dependent gene regulation.This application seeks to challenge and shift current paradigms that form the basis of our understanding of p53 signaling pathways in growth suppression. A detailed molecular profile of p53-dependent transcriptional regulation will be developed and the consequences of perturbing indirect regulators will be determined. Achieving the goals of this proposal will clarify what factors mediate p53-dependent gene regulation and how they contribute to tumor suppression. Understanding how p53 suppresses tumor progression may identify novel therapeutic targets to control cell growth.