Investigating the functions of the miR-17~92 family of oncogenic microRNA cluster

致癌microRNA簇miR-17~92家族功能的研究

基本信息

批准号：
8034401
负责人：
Andrea Ventura
金额：
$ 38.42万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2015-01-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): MicroRNAs are small non-coding RNAs that have recently emerged as important modulators of gene expression in metazoans and in plants. In addition to playing important roles in normal development and differentiation, some miRNAs have been shown to act as oncogenes and tumor suppressors. In particular, several lines of evidence indicate that the miR-17~92 cluster includes at least one oncogenic miRNA. Amplification and overexpression of this cluster are frequently observed in a subset of human B-cell lymphomas and in a significant number of other human cancers. The goal of this project is to investigate the biological functions, the physiological targets and the oncogenic properties of this cluster and its two paralogs: miR-106b~25 and miR-106a~363. We propose to use the laboratory mouse as the model organism for these studies and we have already generated mice carrying conditional and constitutive loss-of-function alleles of these three clusters. This application is articulated in three specific aims. In aim 1 we will investigate the functions of miR-17~92 and its two paralogs in mammalian development. The experiments proposed in this aim will allow us to genetically dissect the miR-17~92 cluster and to assign specific biological functions to the six microRNAs that it encodes. In addition they will allow us to determine the extent of functional overlap between miR-17~92 and its two paralogs, miR-106~363 and miR-106b~25. In aim 2, we will investigate the role of miR-17~92 in tumor maintenance in the context of c-Myc induced B cell lymphomas. The rationale for this specific aim is based on the observation that c-Myc is a potent transcriptional transactivator of miR-17~92 and on our own preliminary studies showing that acute deletion of miR-17~92 leads to a dramatic reduction in the proliferation of E5-Myc B-lymphoma cells. The ultimate goal of this aim is to determine the therapeutic potential of pharmacological antagonists of miR-17~92 in a preclinical model of B cell lymphomas. The objective of aim 3 is to identify the set of genes that are physiologic targets of miR-17~92 and to validate their functional relevance in cell-based experiments and in vivo. These goals will be achieved by combining a computation and an experimental approached that takes advantage of the conditional knockout allele of miR- 17~92 that we have recently generated. The work we are proposing will increase our understanding of the biological functions and mechanism of action of this important class of non-coding genes. Of even greater relevance for human health, it will provide insights into the role of miRNAs in the development to human cancer and may pave the way for novel therapeutic approaches based on their pharmacological inhibition.

描述（由申请人提供）：MicroRNA 是小型非编码 RNA，最近已成为后生动物和植物中基因表达的重要调节剂。除了在正常发育和分化中发挥重要作用外，一些 miRNA 还被证明可以充当癌基因和肿瘤抑制基因。特别是，多项证据表明 miR-17~92 簇包含至少一种致癌 miRNA。该簇的扩增和过度表达经常在人类 B 细胞淋巴瘤的子集和大量其他人类癌症中观察到。该项目的目标是研究该簇及其两个旁系同源物：miR-106b~25 和 miR-106a~363 的生物学功能、生理目标和致癌特性。我们建议使用实验室小鼠作为这些研究的模型生物，并且我们已经生成了携带这三个簇的条件性和组成性功能丧失等位基因的小鼠。该应用程序有三个具体目标。在目标 1 中，我们将研究 miR-17~92 及其两个旁系同源物在哺乳动物发育中的功能。这一目标中提出的实验将使我们能够从基因角度剖析 miR-17~92 簇，并为其编码的 6 个 microRNA 分配特定的生物学功能。此外，它们将使我们能够确定 miR-17~92 及其两个旁系同源物 miR-106~363 和 miR-106b~25 之间的功能重叠程度。在目标 2 中，我们将研究 miR-17~92 在 c-Myc 诱导的 B 细胞淋巴瘤背景下肿瘤维持中的作用。这一特定目标的基本原理是基于以下观察：c-Myc 是 miR-17~92 的有效转录反式激活因子，并且我们自己的初步研究表明，miR-17~92 的急性缺失会导致增殖急剧减少E5-Myc B 淋巴瘤细胞。该目的的最终目标是确定 miR-17~92 药理学拮抗剂在 B 细胞淋巴瘤临床前模型中的治疗潜力。目标 3 的目标是确定作为 miR-17~92 生理靶标的一组基因，并验证它们在细胞实验和体内的功能相关性。这些目标将通过结合计算和实验方法来实现，该方法利用我们最近生成的 miR-17~92 的条件敲除等位基因。我们提出的工作将增加我们对这一类重要非编码基因的生物学功能和作用机制的理解。它将提供对 miRNA 在人类癌症发展中的作用的深入了解，并可能为基于其药理抑制的新治疗方法铺平道路，这对人类健康具有更大的意义。