P53 Signaling and Cellular Response after Stress

描述（由申请人提供）：作为对no - od -09-058的回应，NIH宣布恢复法案基金可用于竞争性修订申请，我们为R01拨款CA070856提出竞争性修订，题为“p53信号传导和应激后细胞反应”。p53信号通路是迄今为止在人类肿瘤中发现的最常见的被破坏的通路。由该基金资助的已完成和正在进行的实验已经并将继续测试p53通过靶基因的转录调控来调节应激后的细胞结果的假设，这些靶基因协调生长停滞、修复和生存与凋亡的途径。最初的目标有三个：(1)确定新的p53靶基因产物在调节应激后细胞存活中的作用（重点是EDN2）；(2)确定新型p53靶基因产物参与调节细胞对基因毒性应激敏感性的作用（初步关注RPS27L和ISG20L1）；(3)确定p53及其家族成员对目标基因的组成型调控与应激诱导型调控的机制。我们在这三个目标上都取得了进展，出版物证明了这一点；并且，我们将继续我们的特征选择p53靶基因的建议。然而，一个基因一次的方法是有限的，因为没有一个单一的靶基因可以解释p53的肿瘤抑制活性的一小部分。相反，p53调节了一个广泛的基因网络的转录，这些基因网络涉及多种功能，如细胞周期阻滞、细胞凋亡、衰老和自噬。p53反应的复杂性不仅仅局限于其基因组结合谱，还反映在两个p53同源物（p63和p73）的存在上，它们可以在物理和功能上与p53相互作用。我们将全面的p53基因组结合位点数据与微阵列表达数据叠加，生成一组新的p53调控靶基因。此外，我们将这组p53靶基因与我们的p63和p73分析中类似衍生的靶基因进行了比较，并确定哪些靶基因具有p53家族其他成员的独特或共同调控。考虑到深入表征每个靶基因产物（即抗体产生、模型系统和转化为人类疾病）所需的大量时间和资源，关键的下一步是筛选这组基因，并确定后续分析的优先顺序。我们提出了一个新的目标，涉及一组新的功能表征，p53家族靶基因在生理相关的模型系统中使用高效，高通量的方法。这一目标是扩大调查领域，这将需要招募额外的人员以及购买设备和用品，所有这些行动将刺激经济，并扩大我们对人类肿瘤中最常见的破坏途径的理解。

DESCRIPTION (provided by applicant): In response to NOT-OD-09-058, NIH Announces the availability of Recovery Act Funds for Competitive Revision Applications, we propose a competing revision for the R01 grant CA070856 entitled, "p53 Signaling and Cellular Response After Stress." The p53 signaling pathway is the most commonly subverted pathway yet identified in human tumors. Completed and ongoing experiments funded by this grant have and will continue to test the hypothesis that p53 regulates cellular outcome after stress through transcriptional regulation of target genes that coordinate pathways of growth arrest, repair, and survival versus apoptosis. Three original aims are under pursuit: (1) To determine the role of novel p53 target gene products involved in regulating cell survival after stress (with focus on EDN2); (2) To determine the role of novel p53 target gene products involved in regulating cell sensitivity to genotoxic stress (with initial focus on RPS27L and ISG20L1); and (3) To determine the mechanisms involved in dictating constitutive versus stress-inducible regulation of target genes by p53 and it family members. We have made progress on all three aims as evidenced by publications; and, we will continue our characterization of select p53 target genes as proposed. However, a gene-at-a-time approach is limiting given that no single target gene can explain more than a fraction of the tumor suppressive activity of p53. Instead, p53 regulates the transcription of an extensive network of genes involved in diverse functions such as cell cycle arrest, apoptosis, senescence, and autophagy. The complexity of the p53 response extends beyond just its genomic binding profile, and is reflected by the existence of two p53 homologs (p63 and p73) that can physically and functionally interact with p53 and one another. We overlaid comprehensive p53 genomic binding site data with microarray expression data to generate a panel of novel, p53-regulated target genes. Further, we compared this panel of p53 target genes with similarly derived panels from our p63 and p73 analyses and determined which of the target genes have unique or shared regulation by other members of the p53 family. A critical next step is to filter this panel of genes and prioritize the order of subsequent analyses given the significant investment of time and resources required for the in depth characterization of each target gene product (i.e., antibody production, model systems, and translation to human disease). We propose a new aim that involves functional characterization of a panel of novel, p53 family target genes in physiologically relevant models systems using an efficient, high-throughput approach. This aim is an expanded area of investigation that will require recruitment of additional personnel as well as purchase of equipment and supplies, all actions that will stimulate the economy and expand our understanding of the most commonly subverted pathway yet identified in human tumors. PUBLIC HEALTH RELEVACNE: In response to AARA NOT-OD-09-058, Recovery Act Funds for Competitive Revision Applications, we propose a competing revision for the R01 grant CA070856 entitled, "p53 Signaling and Cellular Response After Stress." Completed and ongoing experiments funded by this grant have and will continue to test the hypothesis, through three specific aims, that p53 regulates cellular outcome after stress through transcriptional regulation of target genes that coordinate pathways of growth arrest, repair, and survival versus apoptosis. We propose a new aim that involves functional characterization of a panel of novel, p53 family target genes in physiologically relevant models systems using an efficient, high-throughput approach; this aim represents an expanded area of investigation that will require recruitment of additional personnel as well as purchase of equipment and supplies, all actions that will stimulate the economy and expand our understanding of the most commonly subverted pathway yet identified in human tumors.