Deregulation of long noncoding RNAs in cancer

项目摘要/摘要 长非编码RNA(LncRNA)MALAT1的异常高表达与肺密切相关 腺癌(LUAD)的进展和患者预后较差，一直被视为潜在的 治疗靶点。然而，这些相关的观察并没有揭示出是否异常表达 MALAT1是肿瘤发生的驱动力，MALAT1过表达促进肿瘤发生的机制是什么 疾病的发展。在初步研究中，我们开发了一种创新的CRISPR激活(CRISPRa) 在患者来源的细胞系和自体小鼠中成功模拟MALAT1过表达的系统 LUAD的模型。引人注目的是，我们发现在肿瘤发生时MALAT1的肿瘤特异性过度表达 启动足以加速小鼠LUAD向侵袭性和转移性疾病的进展， 证明MALAT1的过度表达是癌症发展的驱动因素。我们进一步确定， MALAT1过表达通过改变MALAT1对肿瘤微环境的影响 细胞因子和基质因子的表达。基于这些有希望的发现，我们的中心假设是 在LUAD中MALAT1的逐渐积累通过 转移促进基因表达程序的激活和转移前肿瘤的建立 微环境。在目标1中，我们描述了我们使用高级的、时间控制的鼠标模型来澄清 当MALAT1过表达促进肿瘤进展时，肿瘤发生的阶段，要求 持续的MALAT1过表达，当MALAT1下调时的机会之窗可能具有 治疗效果。目的研究MALAT1过表达对大鼠脑缺血再灌注损伤的非细胞自主性影响。 建立一个有利于转移的利基市场。我们建议对MALAT1依赖的基因进行详细的表征 肿瘤间质在肿瘤发生的不同阶段的变化以及使用遗传模型来探索 候选分泌因子的作用，如炎性细胞因子。最后，目标3概述了我们的计划 MALAT1过表达改变肿瘤表达的分子机制 微环境效应器。我们建议利用最先进的分子生物学方法，与 长期合作者，他们是生物信息学和化学生物学的专家，以确定MALAT1 过表达通过显性作用在转录或转录后水平影响靶基因 消极或功利性机制，以及通过直接或间接活动。总而言之，这项提案 概述了一个高度创新的实验和概念框架，用于剖析鲜为人知的角色 作为LUAD的一名司机，MALAT1过度表达。除了MALAT1之外，这项工作的广泛意义在于它 阐明异常表达的lncRNAs如何调控癌症发展和揭示 靶向异常表达的lncRNA是否可能具有治疗前景。

Project Summary/Abstract Aberrantly high expression of the long noncoding RNA (lncRNA) Malat1 is strongly associated with lung adenocarcinoma (LUAD) progression and poor patient prognosis and has been pursued as a potential therapeutic target. However, these correlative observations do not reveal whether the aberrant expression of Malat1 is a driver of tumorigenesis and what are the mechanisms by which Malat1 overexpression promotes disease progression. In preliminary studies, we developed an innovative CRISPR activation (CRISPRa) system that successfully models Malat1 overexpression in patient-derived cell lines and autochthonous murine models of LUAD. Strikingly, we uncovered that tumor-specific overexpression of Malat1 at the time of tumor initiation is sufficient to accelerate the progression of murine LUAD to aggressive and metastatic disease, demonstrating that Malat1 overexpression is a driver of cancer development. We further determined that Malat1 overexpression leads to pleiotropic effects on the tumor microenvironment through the altered expression of cytokines and stromal factors. Based on these promising findings, our central hypothesis is that progressive accumulation of Malat1 in LUAD drives the development of aggressive disease through the activation of a metastasis-promoting gene expression program and the establishment of a pro-metastatic tumor microenvironment. In Aim 1, we describe our use of advanced, temporally controlled mouse models to clarify the stage of tumorigenesis when overexpression of Malat1 promotes tumor progression, the requirement for sustained Malat1 overexpression, and the window of opportunity when downregulation of Malat1 may have a therapeutic impact. Aim 2 seeks to investigate the non-cell autonomous effects of Malat1 overexpression in the establishment of a pro-metastatic niche. We propose to perform detailed characterization of Malat1-dependent changes in the tumor stroma at different stages of tumorigenesis as well as use genetic models to explore the contributions of candidate secreted factors, such as inflammatory cytokines. Finally, Aim 3 outlines our plans to elucidate the molecular mechanism by which overexpressed Malat1 alters the expression of tumor microenvironment effectors. We propose to utilize state-of-the-art molecular biology approaches and work with long-term collaborators, who are experts in bioinformatics and chemical biology, to determine whether Malat1 overexpression affects target genes at the transcriptional or post-transcriptional level, through dominant negative or gain-of-function mechanisms, and through direct or indirect activities. In summary, this proposal outlines a highly innovative experimental and conceptual framework for dissecting the poorly understood role of overexpressed Malat1 as a driver in LUAD. Beyond Malat1, the broad significance of this work lies in its potential to elucidate how aberrantly expressed lncRNAs modulate cancer development and to uncover whether targeting aberrantly expressed lncRNAs might hold a therapeutic promise.