Recognition of Chromosomal DNA by Double-Stranded RNA

描述（由申请人提供）：短干扰RNA（siRNA）识别mRNA的能力得到广泛认可。siRNA正在进入I期试验，但其影响人类健康的最终潜力尚不清楚。像任何候选药物一样，需要探索许多选择以使双链RNA更有效和更通用。我们已经观察到，21个碱基的反基因RNA（agRNA）互补的启动子序列内的双链体染色体DNA作为基因表达的有效抑制剂。核连续测定证明agRNA在转录水平上阻断基因表达。最近，我们发现了激活基因表达的agRNA，为在实验室和临床中使用双链RNA开辟了新的途径。目的：本提案的目的是了解agRNA的性质，阐明其作用机制，并表征其基因沉默或激活的潜力。在目的1中，我们研究了Argonaute蛋白在基因激活中的参与。在目标2中，我们研究了RNA介导的染色体DNA识别机制，并开发了具有改进效力和特异性的化学修饰RNA。在目标3中，我们通过建立将RNA序列与沉默效力相关联的数据库来开发用于预测agRNA活性的规则。对于目标4，我们提出了计算和实验策略来识别与人类或病毒基因的转录起始位点共享同一性的microRNA。基本原理：我们提出的研究将描述agRNA的机制。我们的实验将对生物医学研究产生重大影响，因为它们将1）将RNA介导的治疗范围扩大到染色体DNA内的靶点，2）开发使用agRNA控制基因表达的规则，3）检查agRNA在细胞调控基因表达的正常途径中的作用。我们的研究将大大扩大开发RNA药物的潜力。与公共卫生的相关性：增加或减少基因表达的药物有可能被开发为治疗大多数疾病的药物。我们的工作是相关的，因为它描述了一种增加或减少疾病相关蛋白质水平的新策略。具体来说，我们的工作将扩大设计RNA药物以减少基因表达的选择，并通过提供设计RNA以增加基因表达的新策略来填补未满足的需求。

DESCRIPTION (provided by applicant): The ability of short interfering RNAs (siRNAs) to recognize mRNA is widely appreciated. siRNAs are entering Phase I trials, but their ultimate potential to impact human health is unclear. Like any drug candidate, many options will need to be explored to make duplex RNAs more potent and more versatile. We have observed that 21-base antigene RNAs (agRNAs) complementary to promoter sequences within duplex chromosomal DNA act as potent inhibitors of gene expression. Nuclear run-on assays demonstrate agRNAs block gene expression at the level of transcription. Most recently, we have discovered agRNAs that activate gene expression, opening up new avenues for using duplex RNAs in the laboratory and the clinic. Objectives: The objective of this proposal is to understand the properties of agRNAs, elucidate their mechanism of action, and characterize their potential for gene silencing or activation. In Aim 1, we investigate involvement of argonaute proteins in gene activation. In Aim 2, we examine the mechanism of RNA-mediated recognition of chromosomal DNA and develop chemically modified RNAs with improved potencies and specificites. In Aim 3, we develop rules for predicting agRNA activity by building a database correlating RNA sequence with silencing potency. For Aim 4, we propose computational and experimental strategies to identify microRNAs that share identity with transcription start sites for human or viral genes. Rationale: Our proposed research will characterize the mechanism of agRNAs. Our experiments will have a substantial impact on biomedical research because they will 1) expand the reach of RNA-mediated therapy to targets within chromosomal DNA, 2) develop rules for using agRNAs to control gene expression, and 3) examine the role of agRNAs in normal pathways for cellular regulation of gene expression. Our studies will significantly expand the potential for developing RNA drugs. Relevance to Public Health: Agents that increase or decrease gene expression have the potential to be developed as agents for treating most diseases. Our work is relevant becauses it describes a new strategy for increasing or decreasing the levels of proteins involved in disease. Specifically, our work will expand the options available for designing RNA drugs to reduce gene expression and fills an unmet need by providing a new strategy for designing RNAs to increase gene expression.