The Role of JAK2 in ILEI-Induced Cancer Stem Cell Formation

JAK2 在 ILEI 诱导的癌症干细胞形成中的作用

• 批准号: 9049982
• 负责人: Ken Noguchi
• 金额: $ 4.52万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9049982
• 关键词: Address; Affect; Binding; Biological Assay; Breast Cancer Cell; Breast Cancer Patient; Breast Cancer cell line; Breast cancer metastasis; Cause of Death; Cell Line; Cell-Cell Adhesion; Cells; Developmental Process; Disease; Epithelial Cells; Exhibits; Fatty acid glycerol esters; Genes; Goals; Heterogeneous-Nuclear Ribonucleoproteins; Immunoblotting; Immunoprecipitation; In Vitro; Interleukins; JAK2 gene; Janus kinase 2; Lead; Malignant Neoplasms; Mammary gland; Mammospheres; Measures; Mesenchymal; Messenger RNA; Metastatic Neoplasm to the Lung; Metastatic breast cancer; Metastatic to; Modeling; Molecular; Mus; Neoplasm Metastasis; Phenotype; Polyribosomes; Primary Neoplasm; Property; RNA; RNAi vector; Regulation; Relapse; Repression; Research; Role; SCID Mice; STAT3 gene; Signal Pathway; Signal Transduction; System; Transcript; Transforming Growth Factor beta; Translating; Translational Regulation; Translations; Tumor Suppressor Proteins; Work; bioluminescence imaging; cancer care; cancer stem cell; cofactor; cytokine; epithelial to mesenchymal transition; in vivo; inhibitor/antagonist; interest; knock-down; mortality; neoplastic cell; new therapeutic target; novel; novel therapeutics; overexpression; public health relevance; research study; targeted treatment; tumor

 DESCRIPTION (provided by applicant) Metastatic disease causes the mortality of most breast cancer patients, but the molecular mechanism of metastasis remains unclear. One hypothesis is that a specific subset of primary breast cancer cells known as cancer stem cells (CSCs) contributes to metastatic outgrowths (1). It has been shown that cells that have undergone a TGF-β-induced epithelial-to-mesenchymal transition (EMT) possess CSC properties (2). Because traditional chemotherapeutics cannot eradicate CSCs, clarifying the molecular mechanism of TGF-β-induced CSC formation could allow for targeted therapies against CSCs and provide a paradigm shift for cancer care. One of the ways TGF-β can induce EMT is the tumor suppressor hnRNP-E1 (3-5). Under normal conditions hnRNP-E1 binds and inhibits the translation of EMT-related mRNAs, but TGF-β treatment releases hnRNP-E1 from the mRNAs, allows for translation, and induces EMT. As stated previously, cells that have undergone a TGF-β-induced EMT possess CSC properties so we wanted to know the downstream effectors of TGF- β/hnRNP-E1 that confer CSC properties. We began our search by focusing on genes that were regulated by both TGF-β and hnRNP-E1, and chose the cytokine Interleukin-like EMT Inducer (ILEI). Preliminary results have shown that ILEI is necessary but not sufficient to activate STAT3 signaling and initiate CSC formation in vitro. Our previous work suggested that JAK2, a canonical activator of STAT3 signaling, was regulated by the same TGF-β/hnRNP-E1 mechanism as ILEI. These findings lead us to hypothesize that ILEI requires an additional TGF-β/hnRNP-E1-regulated gene such as JAK2 to phosphorylate STAT3 and initiate CSC formation. This hypothesis will be addressed through the following Specific Aims. Aim 1 will establish the role of TGF-β and hnRNP-E1 in JAK2 expression. Polysome profiling and RNA-Immunoprecipitations will confirm whether JAK2 is translationally regulated by hnRNP-E1. Aim 2 will determine the role of JAK2 in ILEI signaling. JAK2 will be modulated in several cell lines, and we will measure its effect on STAT3 activation as well as mammosphere formation. Aim 3 will validate the in vivo significance of ILEI signaling in CSC formation. We are interested in CSCs because of their putative role in metastatic outgrowths. Thus, in our final aim we will use a murine breast cancer metastasis model and apply the JAK inhibitor ruxolitinib to block ILEI signaling. These Aims will support the targeting of ILEI signaling as a novel therapy against metastatic breast cancer.

 描述（申请人提供）转移性疾病导致大多数乳腺癌患者死亡，但转移的分子机制仍不清楚。一种假设是，被称为癌症干细胞（CSC）的原发性乳腺癌细胞的特定子集有助于转移性生长（1）。已经表明，经历了TGF-β诱导的上皮-间充质转化（EMT）的细胞具有CSC特性（2）。由于传统的化疗药物不能根除CSC，因此阐明TGF-β诱导的CSC形成的分子机制可以允许针对CSC的靶向治疗，并为癌症护理提供范式转变。TGF-β诱导EMT的方式之一是肿瘤抑制因子hnRNP-E1（3-5）。在正常条件下，hnRNP-E1结合并抑制EMT相关mRNA的翻译，但TGF-β治疗从mRNA中释放hnRNP-E1，允许翻译并诱导EMT。如前所述，经历了TGF-β诱导的EMT的细胞具有CSC特性，因此我们想知道赋予CSC特性的TGF- β/hnRNP-E1的下游效应物。我们通过关注受TGF-β和hnRNP-E1调节的基因开始了我们的搜索，并选择了细胞因子白介素样EMT诱导剂（ILEI）。初步结果表明，ILEI是必要的，但不足以激活STAT 3信号转导和启动CSC形成在体外。我们以前的工作表明，JAK 2是STAT 3信号传导的典型激活剂，与ILEI一样受TGF-β/hnRNP-E1机制的调节。这些发现使我们假设ILEI需要额外的TGF-β/hnRNP-E1调节基因如JAK 2来磷酸化STAT 3并启动CSC形成。这一假设将通过以下具体目标来解决。目的1探讨TGF-β和hnRNP-E1在JAK 2表达中的作用。多核糖体分析和RNA免疫沉淀将证实JAK 2是否受hnRNP-E1的调控。目的2将确定JAK 2在ILEI信号传导中的作用。JAK 2将在几种细胞系中被调节，我们将测量其对STAT 3激活以及乳腺球形成的影响。目的3将验证ILEI信号传导在CSC形成中的体内意义。我们对CSC感兴趣是因为它们在转移性副产物中的假定作用。因此，在我们的最终目标中，我们将使用鼠乳腺癌转移模型并应用JAK抑制剂ruxolitinib来阻断ILEI信号传导。这些目标将支持靶向ILEI信号传导作为针对转移性乳腺癌的新疗法。