The Role of miRNAs in Glioma Stem Cell and Glioma Biology

miRNA 在神经胶质瘤干细胞和神经胶质瘤生物学中的作用

• 批准号: 7966059
• 负责人: Howard Fine
• 金额: $ 73.26万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7966059
• 关键词: 5' Untranslated Regions; Apoptosis; Astrocytoma; Binding; Biological; Biological Assay; Biology; Brain; Brain Neoplasms; Cell Cycle Arrest; Cell Proliferation; Cells; Code; Collection; Computer Simulation; Data; Detection; Development; Down-Regulation; Embryonic Development; Epigenetic Process; Functional RNA; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genomics; Glioma; Gliomagenesis; Hand; Human; Human Genome; Loss of Heterozygosity; Maintenance; Mammals; Methods; MicroRNAs; Modeling; Molecular Profiling; Mus; Neuronal Differentiation; Neurons; Nucleotides; Oncogenes; Oncogenic; Organ; PPP3CA gene; Process; Proliferating; Proteins; Publishing; Regulation; Reverse Transcriptase Polymerase Chain Reaction; Role; Sampling; Stem cells; Testing; Tissues; Transcript; Translations; Tumor Suppressor Genes; Validation; Work; base; cancer cell; glioma cell line; in vitro Model; in vivo; interest; mouse model; therapeutic target; tumor

MicroRNAs that are over expressed in tumors might diminish the level of expression of targeted tumor suppressor genes whereas microRNAs down regulated might repress oncogenic genes contributing to the neoplasic process (oncomirs). Also, miRNAs are frequently located in regions of loss of heterozygosity, regions of amplification, or common breakpoint regions and they have been identified to regulate the expression of tumor-associated genes in several tumors including GBM. Several studies have been published to date analyzing miRNA expression profiles in normal brain and brain tumors using different detection methods. Analysis of murine and human brain miRNA indicated distinctive expression of miR-9,-101,-124 and -132 among others. miRNAs -10b and -21 have been found upregulated in astrocytic tumors appearing the former to work as an oncogene decreasing apoptosis in the malignant cells, whereas miRNA-124 and -137 were down regulated and involved in promotion of neuronal differentiation of brain tumor initiating cells (BTIC) and GBM cell cycle arrest. However, little is know about the expression levels and involvement by target genes regulation of miRNAs in astrocytic brain tumors or BTIC. To better understand the role of miRNAs in the regulation of GBM, we have started generating and comparing the global profile of expression of 365 miRNAs using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) based assays in primary GBM and BTIC derived from them, as well as neuronal stem cells and established glioma cell lines in proliferating and differentiating conditions, to identify specific miRNAs alterations. This analysis is revealing statistically significant downregulation miRNAs in tumors as well as in BTIC vs. non-tumor samples. Furthermore, this expression profile is corroborating BTIC as better models at miRNA level for the study of astrocytic brain tumors than established glioma cell lines, as we have previously described based on their genomic/gene expression profiles. We are also determining the correlation between expression of the miRNAs included in our study and the particular CNA or copy number alterations (deleted/amplified regions) of our tumor/ BTISC samples. miRNAs with non concordant CNA/expression level indicate a possible epigenetic regulation, that could point them as interesting therapeutics targets. This preliminary profile is being used in two ways. On one hand, miRNA analysis will be extended to GMDI collection of brain tumors adding highly valuable information to our already extensive data from them. On the other hand, biological validation of the involvement in gliomagenesis, cell proliferation or invasion of particular miRNAs and their specific targeted genes is being performed in our BTIC in vitro model as well as in vivo mouse models.

肿瘤中过度表达的 MicroRNA 可能会降低靶向肿瘤抑制基因的表达水平，而下调的 MicroRNA 可能会抑制有助于肿瘤形成过程的致癌基因 (oncomirs)。此外，miRNA 经常位于杂合性缺失区域、扩增区域或常见断点区域，并且已被鉴定可调节包括 GBM 在内的多种肿瘤中肿瘤相关基因的表达。迄今为止，已经发表了几项研究，使用不同的检测方法分析正常脑和脑肿瘤中的 miRNA 表达谱。对小鼠和人脑 miRNA 的分析表明 miR-9、-101、-124 和 -132 等的独特表达。已发现 miRNA -10b 和 -21 在星形细胞肿瘤中上调，前者似乎作为癌基因减少恶性细胞的凋亡，而 miRNA-124 和 -137 下调并参与促进脑肿瘤起始细胞 (BTIC) 的神经元分化和 GBM 细胞周期停滞。然而，对于星形细胞脑肿瘤或 BTIC 中 miRNA 的表达水平和靶基因调控的参与知之甚少。为了更好地了解 miRNA 在 GBM 调节中的作用，我们开始使用基于定量逆转录酶聚合酶链式反应 (qRT-PCR) 的检测方法，在原代 GBM 和源自 365 个 miRNA 的 BTIC 以及增殖和分化条件下的神经元干细胞和已建立的神经胶质瘤细胞系中生成和比较 365 个 miRNA 的全局表达谱，以识别特定的 miRNA 变化。该分析揭示了肿瘤以及 BTIC 与非肿瘤样本中 miRNA 的下调具有统计学意义。此外，这一表达谱证实了 BTIC 在 miRNA 水平上是比已建立的神经胶质瘤细胞系更好的 miRNA 水平模型，正如我们之前根据其基因组/基因表达谱所描述的那样。我们还在确定我们研究中包含的 miRNA 的表达与我们的肿瘤/BTISC 样本的特定 CNA 或拷贝数改变（删除/扩增区域）之间的相关性。 CNA/表达水平不一致的 miRNA 表明可能存在表观遗传调控，这可能会将它们作为有趣的治疗靶点。该初步概况有两种用途。一方面，miRNA 分析将扩展到脑肿瘤的 GMDI 收集，为我们已经广泛的数据添加非常有价值的信息。另一方面，我们的 BTIC 体外模型以及体内小鼠模型正在对特定 miRNA 及其特定靶基因参与神经胶质瘤发生、细胞增殖或侵袭进行生物学验证。