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

• 批准号: 10437541
• 负责人: Ivan D'Orso
• 金额: $ 8.2万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 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/10437541
• 关键词: Abnormal Cell; Acute; Address; Affect; Applications Grants; Back; Binding; Biochemical; Biochemical Genetics; 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; 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; genetic approach; improved; insight; loss of function; lung cancer cell; morphogens; new therapeutic target; novel; pancreatic differentiation 2 protein; prevent; programs; response; sarcoma; small molecule; therapeutic target; transcription factor; tumor; tumorigenesis; uncontrolled cell growth; unpublished works

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.

项目摘要 肿瘤补充剂（TS）通过作用多种水平调节细胞生长和死亡的平衡。放松管制 这些层次结构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的反应 可用的治疗。因此，对这些过程有更好的了解和新颖的识别 TS损失时的治疗靶标在癌症生物学领域是优先事项。数十年的工作定义了如何 p14arf（替代阅读框架）TS以p53依赖性方式进行，以防止结核病。 但是，ARF还以p53独立的方式运行，以潜在的“备份p53”，但机制是 保持不当理解。该领域还有一个想法，可以研究肿瘤抑制机制和 利用基本的生物学到治疗机会。在这种情况下，该研究建议的主要目标 是为了定义ARF（p53损失时重新激活）功能以限制肿瘤启动子程序。我们未发表的 研究定义了先前被忽视的ARF肿瘤抑制机制。首先，损失p53， 重新激活的ARF选择性靶向编码的基因上的聚合酶相关因子1复合物（PAF1C） 促增长的GDF和BMP配体以限制异常细胞生长。其次，主要p53 - / - 损失ARF 细胞驱动抑制GDF/BMP程序导致SMAD1/5磷酸化和靶基因激活 （“致癌GDF/SMAD轴”），表明在双TS（p53和ARF）上产生了致癌脆弱性 损失作为替代性治疗靶标。但是，尚不清楚ARF如何使PAF1C失活 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。 这个小的赠款提案旨在解决ARF如何以基因特异性的方式使PAF1C失活 限制肿瘤启动子程序并评估靶向致癌的治疗价值 GDF/SMAD程序。这些提案中的工作由以前的发现和知识差距指导 为了测试ARF结合PAF1和基因特异性因子Runx1的中心假设以阻断PAF1C 以基因特异性方式组装，从而限制肿瘤启动子程序。测试基础 假设，我们将利用生化和遗传方法以及临床和分子注释 临床前模型。特别是，我们将首先研究ARF如何结合PAF1和RUNX1以阻止PAF1C 以基因特异性方式组装（AIM 1），然后探测带有双TS（P53和ARF）损失的肿瘤 表现出致癌GDF/SMAD轴的重新激活，并检查其治疗和诊断潜力（AIM 2）。共同阐明ARF负调节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 靶向双重ARF和p53失活的癌症的TS损失的机会（例如肉瘤，胰腺和 肺腺癌），该瘤与NCI的使命是识别新的目标以从 诊所的长凳。