Control of Breast Cancer Metastasis by Epstein-Barr Virus microRNA

EB 病毒 microRNA 控制乳腺癌转移

• 批准号: 9187428
• 负责人: KAZUKO NISHIKURA
• 金额: $ 39.43万
• 依托单位: WISTAR INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9187428
• 关键词: 3' Untranslated Regions; ADAR1; Adenosine; Animals; Binding Sites; Biogenesis; Biological Assay; Breast Cancer Patient; Breast Cancer Treatment; Breast Cancer cell line; Breast cancer metastasis; Burkitt Lymphoma; Cause of Death; Cells; Clinical; Collection; Complex; Detection; Development; Disease; Double-Stranded RNA; Doxycycline; Epithelial; Epstein-Barr Virus Infections; Epstein-Barr Virus latency; Etiology; Fatty acid glycerol esters; Future; Gene Expression; Genes; Goals; Hodgkin Disease; Human; Human Herpesvirus 4; Immunoblotting; Implant; Injection of therapeutic agent; Inosine; Lead; Luciferases; Lung; MCF7 cell; Malignant Neoplasms; Mammary Neoplasms; Mammary gland; Measurement; Mediating; Messenger RNA; Metastatic Neoplasm to Lymph Nodes; Metastatic breast cancer; Metastatic to; MicroRNAs; Monitor; Mus; Nasopharynx Carcinoma; Neoplasm Metastasis; Pathologist; Patients; Phenotype; Play; Population; Preventive Intervention; Primary Neoplasm; Proteins; Quantitative Reverse Transcriptase PCR; RNA; RNA Editing; RNA Interference; Reporting; Research; Research Proposals; Resources; Role; SCID Mice; Snails; Specimen; Subfamily lentivirinae; Testing; Tetracyclines; Therapeutic; Transcript; Virus; Virus Diseases; adenosine deaminase; cell motility; cranium; epithelial to mesenchymal transition; experimental study; implantation; in vivo; in vivo imaging system; insight; knock-down; malignant breast neoplasm; mouse model; overexpression; public health relevance; slug; small hairpin RNA; transcription factor; tumor

DESCRIPTION (provided by applicant): Adenosine deaminase acting on RNA (ADAR) converts adenosine to inosine specifically in dsRNA (A-to-I RNA editing). Our pioneering studies demonstrated the involvement of A-to-I RNA editing in the control of miRNA biogenesis and function. We recently found that loading of the EBV (Epstein-Barr-virus) miRNA miR- BART6 onto a functional RISC complex is inhibited by A-to-I editing of its primary transcript (pri-miR-BART6) by ADAR1. Moreover, four binding sites of miR-BART6-5p were identified within the human Dicer mRNA 3'UTR, revealing a unique strategy of EBV to manipulate the host RNAi mechanism. Tumor metastasis is the most common cause of death in patients with cancer, including breast cancer. The Epithelial-to-Mesenchymal Transition (EMT) plays an important role in metastasis. Snail, Slug, and Twist have been identified as major regulators of EMT. In addition to these conventional transcription factor proteins, miRNAs have emerged as new key factors that control EMT. Recent studies suggest that two miRNAs, miR- 103 and miR-107, promote the EMT by silencing Dicer and thereby repressing global synthesis of miRNAs, including a major EMT-inhibitory miRNA, miR-200. EBV is one of the most common human viruses, infecting more than 90% of the world's population, and association of latent EBV infection with a variety of human cancers such as Burkitt's lymphoma, Hodgkin's disease, and nasopharyngeal carcinoma is well established. EBV is frequently detected in human breast cancer specimens. Furthermore, more frequent detection of EBV in higher grade (metastatic) breast cancers has been reported. However, very little is known about the relevance of EBV to breast cancer causation and in particular metastasis. Recent studies by us indicate a previously unexplored possibility that EBV infection may play an important role in progression of breast tumors to metastasis. We hypothesize that miR-BART6-5p and its editing by ADAR1 control EMT through targeting Dicer, and contribute to metastasis of EBV positive breast cancer. Information obtained through this research proposal may lead to a new intervention for the prevention or therapeutic treatment of metastatic breast cancer. The long-term goal of this project is to better understand functions of EBV miR-BART6 in metastasis and the control mechanism mediated via A-to-I RNA editing. Specifically, we will determine: 1) the function of miR-BART6 RNAs in promotion of EMT in human breast cancer cell lines; 2) the significance of RNA editing in the EMT promoting function of miR-BART6; 3) the role of miR-BART6 in vivo in breast cancer metastasis using an orthotopic tumor implantation mouse model; and 4) the miR-BART6 and ADAR1 expression levels in human breast tumor specimens and their relevance to metastatic progression.

描述（由申请人提供）：作用于RNA的腺苷脱氨酶（ADAR）在dsRNA（A到I RNA编辑）中特异性地将腺苷转化为肌苷。我们的开创性研究证明了 A-to-I RNA 编辑参与了 miRNA 生物发生和功能的控制。我们最近发现，ADAR1 对 EBV（Epstein-Barr 病毒）miRNA miR-BART6 的初级转录本 (pri-miR-BART6) 进行 A-to-I 编辑，会抑制其加载到功能性 RISC 复合体上。此外，在人 Dicer mRNA 3'UTR 内鉴定出 miR-BART6-5p 的四个结合位点，揭示了 EBV 操纵宿主 RNAi 机制的独特策略。肿瘤转移是癌症患者最常见的死亡原因，包括乳腺癌。上皮间质转化（EMT）在转移中发挥重要作用。 Snail、Slug 和 Twist 已被确定为 EMT 的主要监管者。除了这些传统的转录因子蛋白外，miRNA 已成为控制 EMT 的新关键因子。最近的研究表明，两种 miRNA，miR-103 和 miR-107，通过沉默 Dicer 从而抑制 miRNA 的整体合成来促进 EMT，其中包括主要的 EMT 抑制 miRNA，miR-200。 EBV 是最常见的人类病毒之一，感染了世界上 90% 以上的人口，并且潜伏 EBV 感染与多种人类癌症（如伯基特淋巴瘤、霍奇金病和鼻咽癌）之间的关联已得到充分证实。 EBV 经常在人类乳腺癌样本中检测到。此外，据报道，在较高级别（转移性）乳腺癌中更频繁地检测到 EBV。然而，人们对 EBV 与乳腺癌病因，特别是转移的相关性知之甚少。我们最近的研究表明，EBV 感染可能在乳腺肿瘤进展至转移过程中发挥重要作用，这一此前未曾探索过的可能性。我们假设 miR-BART6-5p 及其 ADAR1 编辑通过靶向 Dicer 控制 EMT，并有助于 EBV 阳性乳腺癌的转移。通过这项研究计划获得的信息可能会导致预防或治疗转移性乳腺癌的新干预措施。该项目的长期目标是更好地了解 EBV miR-BART6 在转移中的功能以及通过 A-to-I RNA 编辑介导的控制机制。具体来说，我们将确定：1）miR-BART6 RNA在促进人乳腺癌细胞系EMT中的功能； 2）RNA编辑在miR-BART6促进EMT功能中的意义； 3）使用原位肿瘤植入小鼠模型观察miR-BART6在体内乳腺癌转移中的作用； 4) 人类乳腺肿瘤标本中的 miR-BART6 和 ADAR1 表达水平及其与转移进展的相关性。