Delineating ARF negative regulation of PAF1C-dependent oncogenic programs

描绘 ARF 对 PAF1C 依赖性致癌程序的负调控

基本信息

批准号：
10588156
负责人：
Ivan D'Orso
金额：
$ 8.04万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-08 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10588156
关键词：
Abnormal Cell Acute Address Affect Applications Grants Binding Biochemical Biological Process Biology CDKN2A gene Cancer Biology Cancer Patient Cancer cell line Cell Death Cell Line Cells Clinic Clinical Complex Data Development Diagnostic Differentiation and Growth Equilibrium Exhibits GDF15 gene Gene Activation Gene Expression Regulation Genes Genetic Transcription Goals Growth Human In Vitro Interruption Knowledge Ligands Lung Adenocarcinoma Maintenance Malignant Neoplasms Mission Molecular Oncogenic Pancreatic Adenocarcinoma Patients Phosphorylation Pre-Clinical Model Process RUNX1 gene Reading Frames Regulation Repression Research Proposals Sampling Signal Transduction Specificity Specimen System TP53 gene Testing Therapeutic Tumor Promoters Tumor Suppression Tumor Suppressor Proteins Work Xenograft procedure bench to bedside bone cell growth derepression genetic approach improved insight lung cancer cell morphogens new therapeutic target novel pancreatic differentiation 2 protein prevent programs response restraint sarcoma small molecule therapeutic target transcription factor tumor tumorigenesis uncontrolled cell growth unpublished works

项目摘要

PROJECT SUMMARY Tumor suppressors (TS) tune the balance of cell growth and death by acting at multiple levels. Deregulation of any of these hierarchies can promote tumorigenesis, impact cancer patient’s survival and response to currently available treatments. Therefore, having a better understanding of these processes and the identification of novel therapeutic targets upon TS loss is a priority in the field of cancer biology. Decades of work have defined how the p14ARF (Alternative Reading Frame) TS operates in a p53-dependent manner to prevent tumorigenesis. However, ARF also operates in a p53-independent manner to potentially “back-up p53”, but the mechanisms remain poorly understood. There is a regained idea in the field to delve into tumor suppressive mechanisms and to leverage the basic biology to therapeutic opportunities. In this context, the major goal of this research proposal is to define how ARF (reactivated upon p53 loss) functions to restrain tumor promoter programs. Our unpublished studies have defined a previously overlooked mechanism of ARF tumor suppression. First, upon p53 loss, reactivated ARF selectively targets the Polymerase Associated Factor 1 complex (PAF1C) at genes encoding the pro-growth GDF and BMP ligands to restrain abnormal cell growth. Second, loss of ARF in primary p53-/- cells de-repress GDF/BMP programs leading to SMAD1/5 phosphorylation and target gene activation (“oncogenic GDF/SMAD axis”), suggesting oncogenic vulnerabilities accrued upon double TS (p53 and ARF) loss emerge as alternative therapeutic targets. However, it remains unknown how ARF inactivates PAF1C in a gene-specific manner and whether the oncogenic GDF/SMAD axis has any diagnostic and therapeutic value. This small grant proposal aims at addressing how ARF inactivates PAF1C in a gene-specific manner to restrain tumor promoter programs and to evaluate the therapeutic value of targeting the oncogenic GDF/SMAD program. Work in this proposal is guided by these previous findings and critical gaps in knowledge to test the central hypothesis that ARF binds Paf1 and the gene-specific factor RUNX1 to block PAF1C assembly in a gene-specific manner thereby restraining tumor promoter programs. To test the underlying hypothesis, we will leverage biochemical and genetic approaches as well as clinically and molecularly annotated preclinical models. Specifically, we will first investigate how ARF binds Paf1 and RUNX1 to block PAF1C assembly in a gene-specific manner (Aim 1), and then probe if tumors bearing double TS (p53 and ARF) loss exhibit reactivation of the oncogenic GDF/SMAD axis and examine its therapeutic and diagnostic potential (Aim 2). Together, elucidating the mechanisms by which ARF negatively regulates PAF1C-dependent tumor promoter transcriptional programs will improve our understanding of an important biological process and offer alternative opportunities to target TS loss in cancers with dual ARF and p53 inactivation (such as sarcoma, pancreas, and lung adenocarcinoma), which is in-line with NCI’s mission to identify novel targets to move the discoveries from the bench to the clinics.

项目概要肿瘤抑制因子（TS）通过在多个层面发挥作用来调节细胞生长和死亡的平衡。这些层次中的任何一个都可以促进肿瘤发生，影响癌症患者的生存和对当前疾病的反应因此，更好地了解这些过程并识别新的治疗方法。 TS 丧失的治疗目标是癌症生物学领域的一个优先事项，数十年的工作已经确定了如何实现这一目标。 p14ARF（替代阅读框）TS 以 p53 依赖性方式发挥作用，以预防肿瘤发生。然而，ARF 也以独立于 p53 的方式运行，以潜在地“备份 p53”，但其机制目前人们对肿瘤抑制机制的了解仍知之甚少。在这种背景下，利用基础生物学的治疗机会是本研究提案的主要目标。是定义 ARF（p53 丢失后重新激活）如何发挥作用来抑制我们未发表的肿瘤启动子程序。研究已经确定了一个以前被忽视的 ARF 肿瘤抑制机制：首先，p53 缺失后，重新激活的 ARF 选择性地靶向编码基因的聚合酶相关因子 1 复合物 (PAF1C) 促生长 GDF 和 BMP 配体抑制异常细胞生长其次，原代 p53-/- 中 ARF 的缺失。细胞去抑制 GDF/BMP 程序，导致 SMAD1/5 磷酸化和靶基因激活（“致癌 GDF/SMAD 轴”），表明双 TS（p53 和 ARF）产生致癌脆弱性然而，ARF 如何使 PAF1C 失活仍不清楚。基因特异性方式以及致癌 GDF/SMAD 轴是否具有任何诊断和治疗价值。这项小额赠款提案旨在解决 ARF 如何以基因特异性方式灭活 PAF1C 抑制肿瘤促进程序并评估针对致癌基因的治疗价值 GDF/SMAD 计划的工作以这些先前的发现和知识的关键差距为指导。检验 ARF 结合 Paf1 和基因特异性因子 RUNX1 以阻断 PAF1C 的中心假设以基因特异性方式组装，从而抑制肿瘤启动子程序。假设，我们将利用生化和遗传学方法以及临床和分子注释具体来说，我们将首先研究 ARF 如何结合 Paf1 和 RUNX1 来阻断 PAF1C。以基因特异性方式组装（目标 1），然后探测肿瘤是否具有双 TS（p53 和 ARF）丢失表现出致癌 GDF/SMAD 轴的重新激活并检查其治疗和诊断潜力（目标 2). 共同阐明ARF负向调节PAF1C依赖性肿瘤启动子的机制转录程序将提高我们对重要生物过程的理解并提供替代方案通过 ARF 和 p53 双重失活来靶向治疗 TS 丢失的机会（例如肉瘤、胰腺癌和肺腺癌），这符合 NCI 的使命，即新颖地确定目标以将发现转移到到诊所的长凳。