Does the RNA editor Apobec-1 shift microRNA targeting to a tumorigenic effect?

RNA 编辑器 Apobec-1 是否会将 microRNA 靶向转变为致瘤作用？

• 批准号: 8795096
• 负责人: Dewi Harjanto
• 金额: $ 5.42万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8795096
• 关键词: 3' Untranslated Regions; Adenosine; Affect; Amino Acids; ApcMin/+ mice; Area; Automobile Driving; Binding; Bioinformatics; Biological Assay; Cancer Model; Cataloging; Catalogs; Categories; Cells; Characteristics; Chromatin; Code; Custom; Cytosine; DNA; DNA Methylation; DNA Sequence; DNA Sequence Alteration; Data; Deaminase; Development; Disease; Disease Outcome; Disease Progression; Enterocytes; Enzymes; Epigenetic Process; Exhibits; Functional disorder; Gastrointestinal tract structure; Gene Expression; Gene Expression Profile; Genes; Genetic; Genomics; Glioma; Goals; Health; High-Throughput Nucleotide Sequencing; Human; Immunoprecipitation; Inosine; Intestinal Cancer; Intestines; Investigation; Knock-out; Life; Link; Literature; Liver; Malignant Neoplasms; Mammalian Cell; Mediating; Methods; MicroRNAs; Mining; Modeling; Modification; Molecular Biology Techniques; Mus; Oncogenic; Outcome; Phenotype; Play; RNA; RNA Editing; RNA Sequences; RNA Splicing; Research Personnel; Role; Site; Small Intestinal Adenoma; Testing; Tissues; Transcript; Translations; Tumor Burden; Tumorigenicity; Untranslated Regions; Uracil; Work; adenoma; base; cancer cell; chromatin remodeling; crosslink; crosslinking and immunoprecipitation sequencing; epigenetic regulation; gain of function; histone modification; interest; macrophage; neoplastic cell; next generation sequencing; novel; novel diagnostics; research study; tool; transcriptome sequencing; tumor; tumor progression; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): According to the current paradigm, cancer originates in dysfunction at the DNA level. As such, studies into the epigenetic regulation of cancer have historically focused on the effects of DNA methylation, histone modifications, and chromatin remodeling (the last two being outcomes of DNA mutation). However, given that mutational signatures at the DNA level are insufficient to classify many subtypes of cancer, researchers have also begun exploring the role that RNA epigenetics may play in cancer progression. One potential RNA epigenetic mechanism of interest is RNA editing, or the site-specific modification of transcribed RNA by deaminases. RNA editing is known to affect splicing, amino acid coding, and microRNAs (miRNAs) and their targets. Very recently, evidence has emerged to support a direct causative role for adenosine to inosine (A-to- I) RNA editing in cancer (Chen et al., 2013). Here, I seek to determine if cytosine to uracil (C-to-U) editing, mediated by Apobec-1, can play causative roles in cancer progression. Genetic experiments had previously suggested an involvement of Apobec-1 in disease progression in the Apcmin/+ mouse model of intestinal cancer. I am therefore proposing studies to understand the mechanistic role of Apobec-1 mediated RNA editing in the context of cancer progression, in this tumor model. My preliminary data in primary mammalian cells suggest that C-to-U editing can affect translation levels of edited transcripts by modifying miRNA target sites. I hypothesize that Apobec-1-mediated RNA editing promotes a more aggressive phenotype in tumor cells by altering miRNA targeting to affect gene expression. This work will be accomplished by exploiting next generation sequencing, bioinformatics, and molecular biology techniques. Using small intestinal tissue from Apcmin/+ mice, I will: (a) catalog C-to-U edit sites throughout the transcriptome; (b) identify potential miRNA target sites affected by Apobec-1 editing, focusing on those occurring in potentially cancer-related genes; and (c) perform functional assays to evaluate the significance of the identified targets. These experiments aim to establish a direct mechanistic link between Apobec-1-mediated RNA editing and cancer. In addition, they will also provide evidence for a novel mechanism of cancer progression that could extend to all cancers, and will yield both novel diagnostic tools and chemotherapeutic targets.

描述（由申请人提供）：根据当前的范式，癌症起源于DNA水平的功能障碍。因此，对癌症表观调节的研究历史上一直集中在DNA甲基化，组蛋白修饰和染色质重塑的作用上（最后两个是DNA突变的结果）。但是，鉴于DNA水平的突变特征不足以分类许多癌症亚型，研究人员也开始探讨RNA表观遗传学在癌症进展中可能起的作用。感兴趣的一种潜在的RNA表观遗传机理是RNA编辑，或通过脱氨酶对转录RNA的位点特异性修饰。已知RNA编辑会影响剪接，氨基酸编码和microRNA（miRNA）及其靶标。最近，有证据表明腺苷对肌苷（A到I）RNA编辑的直接致病作用（Chen等，2013）。 在这里，我试图确定由APOBEC-1介导的尿素（C-TO-U）编辑是否可以在癌症进展中扮演致病作用。遗传实验先前表明，APOBEC-1参与疾病进展中的APCMIN/+小鼠肠癌模型。因此，我建议研究在癌症模型中，在癌症进展的背景下，APOBEC-1介导的RNA编辑的机理作用。我在原代哺乳动物细胞中的初步数据表明，C-TO-U编辑可以通过修改miRNA靶位点来影响编辑转录本的翻译水平。我假设APOBEC-1介导的RNA编辑通过改变miRNA靶向来影响基因表达，从而促进了肿瘤细胞中更具侵略性的表型。这项工作将通过利用下一代测序，生物信息学和分子生物学技术来完成。使用来自APCMIN/+小鼠的小肠组织，我将：（a）整个转录组中的目录C-TO-U编辑位点； （b）确定受APOBEC-1编辑影响的潜在miRNA靶位点，重点是在潜在癌症相关基因中发生的miRNA靶位点； （c）执行功能测定以评估确定目标的重要性。这些实验旨在在APOBEC-1介导的RNA编辑和癌症之间建立直接的机械联系。此外，它们还将提供有关癌症进展的新机制的证据，该机制可以扩展到所有癌症，并将产生新颖的诊断工具和化学治疗靶标。