Stress and Proliferation States Impact MicroRNA-Mediated Regulation in Cancer

压力和增殖状态影响 MicroRNA 介导的癌症调节

• 批准号: 8826043
• 负责人: Phillip A Sharp
• 金额: $ 47.74万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-14 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8826043
• 关键词: Adult; Alleles; Bibliography; Binding; Cancer Burden; Cancer cell line; Cell Survival; Cells; Cellular Stress; DNA Damage; Development; Epitopes; Family; Generations; Genes; Goals; Grant; Haploidy; Health; Health Care Costs; Homebound Persons; Human; Hypersensitivity; Immunoprecipitation; Individual; Knock-out; Link; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Messenger RNA; MicroRNAs; Missense Mutation; Mus; Mutate; Mutation; Nature; Non-Small-Cell Lung Carcinoma; Null Lymphocytes; Oxygen; Pathway interactions; Phenotype; Point Mutation; Preparation; Property; Protein Binding; Proteins; Public Health; Publications; RNA Sequences; Regulation; Repression; Research; Ribonuclease III; Role; Signal Transduction; Somatic Cell; Stress; System; Testing; Therapeutic; Tissues; Transcript; Tumor Suppressor Proteins; Up-Regulation; Xenograft procedure; arm; base; biological adaptation to stress; blastomere structure; cancer cell; cancer therapy; cell growth; chemotherapy; crosslinking and immunoprecipitation sequencing; deprivation; drug development; embryonic stem cell; endonuclease; enhancing factor; human DICER1 protein; improved; in vitro Model; in vivo; inhibitor/antagonist; malignant phenotype; miRNA expression profiling; mutant; neoplastic cell; novel therapeutics; overexpression; prevent; research study; response; sarcoma; stressor; therapy development; transcriptome sequencing; tumor; tumorigenesis

DESCRIPTION (provided by applicant): MicroRNAs are predicted to regulate a majority of genes in human cells and both overexpression and loss of expression of some miRNAs are correlated with malignant phenotypes in different cancer cells. A decrease in miRNA activity is most commonly observed and may be important for the plasticity of tumor cells to undergo transitions between differentiation states and to grow in different niches. One of the major objectives of this proposal is to investigate the functions of subsets of miRNAs in contributing to the properties of tumor cells and specifically to the ability of these cells to respond to stress. Many therapeutic treatments of cancer induce stress due to DNA damage, presence of unfolded proteins, deprivation of survival signals, and oxygen. We found that loss of miRNA regulation renders many types of cancer cells hypersensitive to such stress agents. For example, deletion of Dicer, a double strand endonuclease required for synthesis of most miRNAs, in many cancer cells yields viable cells that can in fact produce tumors in xenograft challenges but are hypersensitive to stress. Dicer- null human cancers have not been observed but recently sequencing of a haploid Dicer gene in several different types of human cancers identified a specific point mutation that inactivated one RNase III domain. This indicates that these tumor cells are being strongly selected for loss of a subset of miRNAs and for retention of other miRNAs. Cells expressing this mutant Dicer are defective for expression of the let-7 miRNA family but express near normal levels of other miRNAs. The four specific aims of this proposal build from progress over the past four years. First, we will further investigate the nature of factors targeting Argonaute 2 (Ago2) to specific RNA sequences in Dicer null cells. We will also investigate how this targeting enhances the quantitative level of silencing by co-binding miRNA. Second, we will characterize the subset of miRNAs generated by mutations of specific functions of Dicer and determine the consequences of expression of these subsets on tumor phenotype and response to stress. Third we will test if an inhibitor of Dicer should be considered as a promising objective for drug development to treat cancer in conjunction with chemotherapy. And fourth, we will investigate the function of Argonaute that is essential for viability in embryonic stem cells defective for synthesis of miRNAs, i.e. null for Dicer.

描述（由申请人提供）：预测MicroRNA调节人细胞中的大多数基因，并且一些miRNA的过表达和表达缺失与不同癌细胞中的恶性表型相关。最常观察到的是miRNA活性的降低，并且对于肿瘤细胞在分化状态之间经历转变和在不同的小生境中生长的可塑性可能是重要的。该提案的主要目标之一是研究miRNAs子集在促进肿瘤细胞特性中的功能，特别是这些细胞对应激反应的能力。许多癌症的治疗性治疗由于DNA损伤、未折叠蛋白质的存在、生存信号的剥夺和氧气而诱导应激。我们发现，miRNA调控的丧失使许多类型的癌细胞对这些应激剂高度敏感。例如，在许多癌细胞中，Dicer（一种合成大多数miRNA所需的双链核酸内切酶）的缺失产生了实际上可以在异种移植物挑战中产生肿瘤但对应激超敏感的活细胞。尚未观察到Dicer缺失的人类癌症，但最近对几种不同类型的人类癌症中的单倍体Dicer基因的测序鉴定了使一个RNase III结构域失活的特定点突变。这表明这些肿瘤细胞被强烈选择为丢失一个miRNA子集和保留其他miRNA。表达这种突变Dicer的细胞对于let-7 miRNA家族的表达是缺陷的，但表达接近正常水平的其他miRNA。这项建议的四个具体目标是在过去四年所取得进展的基础上提出的。首先，我们将进一步研究靶向Argonaute 2（Ago 2）的因子在Dicer无效细胞中的特异性RNA序列的性质。我们还将研究这种靶向如何通过共结合miRNA来提高沉默的定量水平。其次，我们将表征由Dicer特定功能突变产生的miRNA子集，并确定这些子集表达对肿瘤表型和应激反应的影响。第三，我们将测试Dicer抑制剂是否应该被视为与化疗联合治疗癌症的药物开发的有希望的目标。第四，我们将研究Argonaute的功能，它对合成miRNA有缺陷的胚胎干细胞的生存力至关重要，即Dicer无效。