miR-21 signaling in tumor response to radiation treatment

miR-21信号传导在肿瘤对放射治疗的反应中

基本信息

批准号：
8693551
负责人：
YA WANG
金额：
$ 32.37万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-05-15 至 2019-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8693551
关键词：
A549 Address Affect Apoptosis Area Biopsy Specimen Cells Cellular biology DNA Double Strand Break Data Double Strand Break Repair Embryo Environment Epidermal Growth Factor Receptor Fibroblasts Future Grant Head and Neck Neoplasms Human Immune In Vitro Ionizing radiation Knock-in Mouse Knockout Mice Leg Lung Neoplasms Malignant Neoplasms Mediating Methods MicroRNAs Molecular Biology Molecular and Cellular Biology Mus Normal Cell Nude Mice Pathway interactions Policies Publishing Radiation Radiation Tolerance Radiation therapy Radioresistance Radiosensitization Reagent Regulation Reporting Resistance Role SP1 gene STAT3 gene Signal Transduction Solid Neoplasm Testing Therapeutic Tissues Tumor Cell Line Tumor Tissue United States National Institutes of Health Up-Regulation base design ds-DNA improved in vivo killings mouse model neoplastic cell prevent public health relevance repaired response transcription factor tumor tumor microenvironment tumor xenograft tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Overcoming radioresistance is essential for improving radiotherapy. Recently, we found that miR-21 as an onco-miR involved cell radioresistance through promoting DNA double strand repair. These results suggest that targeting miR-21 is a good strategy for sensitizing tumor cells to radiation; however, since radiation could induce miR-21 up-regulation, the up-regulated miR- 21 could in turn reduce the effects of targeting miR-21 alone on radiosensitization. In addition, the miR-21 status in the surrounding tumor tissue may affect tumor response to ionizing radiation treatment since the tumor microenvironment is an important factor that affects the tumor situation. Therefore, in order to efficiently block the function of miR-21 in tumor radioresistance, we need to know the whole picture of miR-21 signaling in irradiated tumor cells in vitro and in vivo. For this purpose, we designed two aims in this proposal. Aim 1: Determine how IR stimulates miR-21 up-regulation. We will elucidate IR-promoted upstream regulation of miR-21 with the methods and approaches of molecular and cellular biology by answering the following four questions: 1) Whether the IR-activated ATR stimulates miR-21 expression through phosphorylating STAT3 at S694. 2) Whether STAT3 as a transcription factor could directly stimulate the EGFR expression to respond to IR. 3) Whether EGFR inhibits miR-21 maturation through phosphorylating AGO2 at Y393 to respond to IR. 4) Whether miR-21 could directly target p53 that negatively regulates EGFR expression through inhibiting YY1 and SP1 (the transcription factors of EGFR). Aim 2: Determine whether and how miR-21 in the tumor microenvironment affects the tumor response to IR treatment. We will use two mouse models: 1) miR-21 knock-in or knockout mouse model: we will use tumor cells that can grow tumors in these immune efficient mice. 2) nude mouse model: we will use the human tumor cells that can grow xenograft tumors in the immune deficient mice. These tumor cell lines (mouse or human) will be down-regulated with miR-21 or its upstream regulators, subcutaneously inoculated into the hind legs of the mice. We will observe the tumor size and examine the level/activity of miR- 21/its relevant regulators in the tumor tissue and the surrounding tissues after the tumor areas are irradiated. The results from this proposal are expected to help us better understand the role of miR-21 in mediating tumor radioresistance in vitro and in vivo, thus, providing an efficient way to block the miR-21 pathway for improving radiotherapy in the near future.

描述（由申请人提供）：克服放射抗性对于改善放射治疗至关重要。最近，我们发现miR-21作为一种onco-miR通过促进DNA双链修复参与细胞放射抗性。这些结果表明，靶向 miR-21 是使肿瘤细胞对辐射敏感的良好策略。然而，由于辐射可以诱导 miR-21 上调，上调的 miR-21 反过来又可以降低单独靶向 miR-21 对放射增敏的影响。此外，肿瘤微环境是影响肿瘤状况的重要因素，周围肿瘤组织中的miR-21状态可能会影响肿瘤对电离辐射治疗的反应。因此，为了有效阻断miR-21在肿瘤放射抗性中的功能，我们需要了解体外和体内受照射肿瘤细胞中miR-21信号传导的全貌。为此，我们设计了两个目标这个建议。目标 1：确定 IR 如何刺激 miR-21 上调。我们将通过回答以下四个问题，用分子和细胞生物学的方法和手段来阐明IR促进的miR-21上游调控：1）IR激活的ATR是否通过磷酸化STAT3的S694来刺激miR-21的表达。 2）STAT3作为转录因子是否可以直接刺激EGFR表达来响应IR。 3) EGFR是否通过在Y393磷酸化AGO2来抑制miR-21成熟以响应IR。 4) miR-21是否可以通过抑制YY1和SP1（EGFR的转录因子）直接靶向负调控EGFR表达的p53。目标 2：确定肿瘤微环境中的 miR-21 是否以及如何影响肿瘤对 IR 治疗的反应。我们将使用两种小鼠模型：1）miR-21 敲入或敲除小鼠模型：我们将使用可以在这些免疫高效小鼠中生长肿瘤的肿瘤细胞。 2）裸鼠模型：我们将使用能够在免疫缺陷小鼠体内生长异种移植肿瘤的人类肿瘤细胞。这些肿瘤细胞系（小鼠或人）将被 miR-21 或其上游调节因子下调，并皮下接种到小鼠后腿。我们将在肿瘤区域照射后观察肿瘤大小并检查肿瘤组织和周围组织中miR-21/其相关调节因子的水平/活性。该提案的结果有望帮助我们更好地了解 miR-21 在体外和体内介导肿瘤放射抗性中的作用，从而为在不久的将来改善放疗提供阻断 miR-21 通路的有效方法。