Mechanisms underlying USP1-mediated bypass of EWS-FLI1 oncogene-induced replication stress in Ewing sarcoma

USP1介导的EWS-FLI1癌基因诱导的尤文肉瘤复制应激旁路的机制

基本信息

批准号：
10446807
负责人：
GARGI GHOSAL
金额：
$ 35.11万
依托单位：
UNIVERSITY OF NEBRASKA 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：
2022-08-05 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10446807
关键词：
Apoptosis Basic Science Bypass Cell Aging Cell Cycle Cell Cycle Arrest Cell Cycle Progression Cell Death Cell Line Cell Maintenance Cell Proliferation Cell physiology Cells ChIP-seq Childhood Chromosomal translocation Chromosome 11 Chromosome 22 DNA DNA Damage DNA Repair DNA biosynthesis DNA-protein crosslink Data Deubiquitination Development Disease Progression E2F transcription factors EWSR1 gene Epigenetic Process Ewings sarcoma FLI1 gene Family Fiber Gene Expression Gene Fusion Generations Genes Genetic Transcription Genome Genome Stability Genomic Instability Growth HELLS gene Histones In Vitro Lysine Malignant Bone Neoplasm Maps Mediating Mesenchymal Stem Cells Molecular Normal Cell Oncogenes Oncogenic Pathogenesis Pathway interactions Patients Pharmaceutical Preparations Phenocopy Proteins Regulation Role S phase Site Testing Treatment Efficacy Ubiquitin Ubiquitination Xenograft Model base biological adaptation to stress bone cancer cell cell growth chemotherapy chromatin remodeling comparative epigenetic regulation genome wide methylation genome-wide analysis improved in vivo inhibitor insight knock-down methylation pattern mutant new therapeutic target novel overexpression repaired replication stress response sarcoma small molecule standard of care stem cells t(11 22)(q24 q12)targeted treatment transcription factor transcriptome sequencing treatment strategy tumor tumor growth tumorigenesis ubiquitin-protein ligase ubiquitin-specific protease

项目摘要

PROJECT SUMMARY Replication stress leading to genome instability is an early driver of tumorigenesis and has been associated with overexpression of oncogenes. In normal cells, activation of the DNA damage response (DDR) pathway serves as a barrier to tumorigenesis leading to cell cycle arrest inducing cellular senescence or cell death in response to high burden of genome instability. However, in cancer cells upon oncogene-induced replication stress the protective barrier of DDR, cell death and senescence is bypassed leading to uncontrolled cell proliferation. Therefore, deciphering the mechanisms that bypass oncogene-induced replication stress and senescence will help understand the basic science underlying disease progression and will identify new targets for therapy. Ewing sarcoma (EWS) is driven by a chromosomal translocation and in-frame gene fusion between EWSR1 and ETS family of transcription factors. In majority of the EWS cases, the chromosomal translocation results in the generation of EWS-FLI1 oncogene. EWS-FLI1 functions as an aberrant transcription factor that drives the development and progression of EWS. Expression of EWS-FLI1 oncogene leads to oncogene-induced replication stress and genome instability. However, the molecular mechanism underlying bypass of EWS-FLI1 oncogene-induced replication stress response pathways is largely unknown. Our preliminary data shows that USP1 deubiquitinase is overexpressed in EWS cell lines and tumors. USP1 regulates DDR and is required for genome stability and stem cell maintenance. We find that USP1 expression is regulated by EWS-FLI1 in EWS. Importantly, inhibition of USP1 activity using small molecule USP1 inhibitors resulted in growth arrest of EWS cell lines indicating that USP1 expression and activity is important for EWS cell proliferation and progression. Notably, USP1 depletion led to a decrease in the levels of HELLS chromatin remodeling protein. The function of USP1 or HELLS in EWS pathogenesis has not been investigated. In this study, we will examine the regulation of HELLS by USP1 deubiquitinase (Aim 1), determine the mechanism by which USP1 promotes EWS cell proliferation (Aim 2), and determine the effect of USP1 knockdown on EWS tumor formation in vivo and the efficacy of USP1 inhibition in combination with chemotherapeutic drugs at suppressing EWS cell proliferation (Aim 3). Successful completion of this study will unravel novel mechanistic insights into USP1 mediated bypass of EWS-FLI1 oncogene-induced replication stress and help evaluate USP1 targeted treatment strategies for EWS.

项目概要导致基因组不稳定的复制应激是肿瘤发生的早期驱动因素，并且已被证实与癌基因的过度表达有关。在正常细胞中，DNA 损伤反应 (DDR) 的激活途径作为肿瘤发生的屏障，导致细胞周期停滞，诱导细胞衰老或细胞因基因组不稳定的高负担而死亡。然而，在癌基因诱导的癌细胞中复制应激会绕过DDR的保护屏障，导致细胞死亡和衰老不受控制细胞增殖。因此，破译绕过癌基因诱导的复制应激和衰老将有助于了解疾病进展的基础科学，并确定新的目标用于治疗。尤文肉瘤 (EWS) 是由染色体易位和框内基因融合驱动的 EWSR1 和 ETS 转录因子家族。在大多数 EWS 病例中，染色体易位导致 EWS-FLI1 癌基因的产生。 EWS-FLI1 作为一种异常转录因子发挥作用推动EWS的发展和进步。 EWS-FLI1癌基因的表达导致癌基因诱导复制压力和基因组不稳定性。然而，EWS-FLI1旁路的分子机制癌基因诱导的复制应激反应途径在很大程度上是未知的。我们的初步数据表明 USP1 去泛素酶在 EWS 细胞系和肿瘤中过度表达。 USP1 规范 DDR，并且需要基因组稳定性和干细胞维护。我们发现EWS中USP1的表达受到EWS-FLI1的调节。重要的是，使用小分子 USP1 抑制剂抑制 USP1 活性导致 EWS 生长停滞细胞系表明 USP1 表达和活性对于 EWS 细胞增殖和进展很重要。值得注意的是，USP1 缺失导致 HELLS 染色质重塑蛋白水平下降。的功能 USP1 或 HELLS 在 EWS 发病机制中的作用尚未得到研究。在本研究中，我们将研究监管 USP1 去泛素酶对 HELLS 的影响（目标 1），确定 USP1 促进 EWS 细胞的机制增殖（目标 2），并确定 USP1 敲低对体内 EWS 肿瘤形成的影响以及 USP1 抑制与化疗药物联合抑制 EWS 细胞增殖的功效（目标 3）。这项研究的成功完成将揭示 USP1 介导的旁路的新机制见解 EWS-FLI1 癌基因诱导的复制应激，并帮助评估 USP1 靶向治疗策略电子预警系统。