Investigating the role of DUX and miR-34a regulation in cell fate plasticity and cancer

研究 DUX 和 miR-34a 调节在细胞命运可塑性和癌症中的作用

• 批准号: 10293564
• 负责人: Bradley Don Weaver
• 金额: $ 5.18万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-11-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10293564
• 关键词: 3' Untranslated Regions; B-Cell Acute Lymphoblastic Leukemia; B-Lymphocyte Subsets; Binding Sites; Biological Assay; Cancer Biology; Cell Cycle; Cell Fate Control; Cell Proliferation; Cell Therapy; Cell model; Cells; Clinical; Collaborations; DNA Damage; Data; Development; Embryo; Ensure; Epigenetic Process; Facioscapulohumeral Muscular Dystrophy; Family; Feedback; G1 Phase; Genes; Genetic Transcription; Height; Human; Huntsman Cancer Institute at the University of Utah; Knock-out; Knockout Mice; Link; Luciferases; Malignant - descriptor; Malignant Neoplasms; Mammals; Maps; Measures; Mentorship; Messenger RNA; MicroRNAs; Molecular; Mus; Mutate; Mutation; Oncogenic; Pathway interactions; Physicians; Positioning Attribute; Post-Transcriptional Regulation; Probability; RNA; Regenerative Medicine; Regulation; Reporter; Reverse Transcriptase Polymerase Chain Reaction; Role; Scientist; Site; Surgeon; TP53 gene; Techniques; Teratoma; Testing; Therapeutic; Tissues; Totipotency; Totipotent; Transcript; Translational Regulation; Translational Repression; Translations; Tumor Suppressor Proteins; Work; base; cancer therapy; cell growth; cell regeneration; cell type; clinical development; embryo cell; embryo stage 2; embryonic stem cell; epigenetic silencing; experimental study; homeodomain; human tissue; improved; in vivo; insight; mRNA Expression; novel; novel therapeutics; overexpression; prevent; programs; response; ribosome profiling; sarcoma; stem cell fate; targeted cancer therapy; therapy resistant; transcription factor; transcriptome; tumorigenesis

Project Summary Hijacked plasticity of cell fate potential, combined with oncogenic mutations, drives malignant transformation and therapeutic resistance in many cancers. Totipotency – the ability of a cell to become all embryonic and extra- embryonic tissues – represents the height of embryonic/stem cell fate potential in mammals. DUX is a double homeodomain transcription factor that is misexpressed in subsets of B-cell acute lymphoblastic leukemia and round-cell sarcomas. Our lab recently defined DUX (mouse Dux / human DUX4) as a major driver of totipotent developmental programs in mouse and human. Pluripotent mouse embryonic stem cells (mESCs) expressing mouse Dux are potently converted into a ‘2C-like’ totipotent state, which epigenetically and transcriptionally resemble the 2-cell mouse embryo. In vivo, DUX expression is highly transient, and lasts less than a cell cycle in early embryos. Although the transcriptome of totipotency is well studied, it is unclear how the embryo employs post-transcriptional and translational regulation downstream of DUX to establish this plasticity in cell fate, and what mechanisms subsequently restrict developmental potency to ensure proper lineage determination. Recently, we and others have discovered a central role for p53 in DUX activation. P53 is a master tumor suppressor and transcription factor, which also activates the micro-RNA (miRNA) 34 family (a/b/c) in response to DNA damage. miR-34a is expressed in many mouse and human tissues, and is a well-studied tumor suppressor itself, repressing pathways involved in cellular growth and proliferation. Importantly, miR-34a deletion in mESCs confers a high probability of their conversion into a totipotent state, however the mechanisms governing this expanded cell fate plasticity are unclear. We find that loss of miR-34a in mESCs causes accumulation of Dux transcripts, and DUX4 contains a predicted miR-34a target site in its 3’ UTR, suggesting a direct regulatory role of miR-34a. We hypothesize that p53 and miR-34a activate and repress Dux (and/or Dux targets), respectively, forming a feedback loop which regulates the totipotency network and ultimately restricts cell fate plasticity in vivo. Uncovering the mechanisms safe-guarding cell fate potential and preventing oncogenesis in vivo will yield novel insights in both cancer biology and regenerative medicine. I am uniquely positioned to answer these questions in the Cairns Lab within the Huntsman Cancer Institute at the University of Utah. Leveraging our advanced DUX expertise, combined with key collaborations with experts in translational control, I am confident in my abilities to execute the experiments outlined within this proposal. Additionally, my excellent clinical mentorship team, crafted from highly productive physician- and surgeon-scientists, will promote my clinical development as I seek to combine key insights from molecular drivers of cell fate plasticity and oncogenesis into development of novel targets for cancer therapeutics and regenerative medicine.

项目概要 细胞命运潜力的可塑性被劫持，与致癌突变相结合，驱动恶性转化和 许多癌症的治疗耐药性。全能性——细胞变成全部胚胎和非胚胎细胞的能力 胚胎组织——代表哺乳动物胚胎/干细胞命运潜力的高度。 DUX是双 在 B 细胞急性淋巴细胞白血病亚群中错误表达的同源域转录因子 圆形细胞肉瘤。我们的实验室最近将 DUX（小鼠 Dux / 人类 DUX4）定义为全能的主要驱动力 小鼠和人类的发育程序。多能小鼠胚胎干细胞 (mESC) 表达 小鼠 Dux 被有效地转化为“2C 样”全能状态，这在表观遗传和转录上 类似于2细胞小鼠胚胎。在体内，DUX 表达是高度瞬时的，持续时间少于一个细胞周期 在早期胚胎中。尽管全能性的转录组已得到充分研究，但尚不清楚胚胎如何利用 DUX 下游的转录后和翻译调控，以建立细胞命运的可塑性，以及 随后哪些机制限制发育潜力以确保正确的谱系确定。 最近，我们和其他人发现了 p53 在 DUX 激活中的核心作用。 P53是主肿瘤 抑制因子和转录因子，也会激活 micro-RNA (miRNA) 34 家族 (a/b/c) 作为响应 对DNA损伤。 miR-34a 在许多小鼠和人体组织中表达，是一种经过充分研究的肿瘤 抑制因子本身，抑制参与细胞生长和增殖的途径。重要的是，miR-34a 缺失 在 mESC 中，它们有很高的概率转化为全能状态，但是机制 控制这种扩大的细胞命运可塑性尚不清楚。我们发现 mESC 中 miR-34a 的缺失会导致 Dux 转录本的积累，并且 DUX4 在其 3' UTR 中包含预测的 miR-34a 靶位点，表明 miR-34a 的直接调节作用。我们假设 p53 和 miR-34a 激活并抑制 Dux（和/或 Dux 目标），分别形成一个反馈回路，调节全能网络并最终限制 体内细胞命运的可塑性。揭示保护细胞命运潜力并预防细胞命运的机制 体内肿瘤发生将为癌症生物学和再生医学带来新的见解。我是独一无二的 凯恩斯大学亨茨曼癌症研究所的凯恩斯实验室可以回答这些问题 犹他州。利用我们先进的 DUX 专业知识，结合与转化专家的关键合作 控制，我对自己执行本提案中概述的实验的能力充满信心。另外，我的 由高产的内科医生和外科医生科学家组成的优秀临床指导团队将促进 我的临床发展，因为我寻求将细胞命运可塑性分子驱动因素的关键见解与 肿瘤发生转化为癌症治疗和再生医学新靶点的开发。