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: 9252224
• 负责人: Ken Noguchi
• 金额: $ 4.57万
• 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/9252224
• 关键词: Address; Alpha Cell; 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; Immunoprecipitation; In Vitro; Injectable; 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; Quantitative Reverse Transcriptase PCR; RNA; RNAi vector; Regulation; Relapse; Repression; Research; Role; SCID Mice; STAT3 gene; Signal Pathway; Signal Transduction; System; Transcript; Transforming Growth Factor alpha; Transforming Growth Factor beta; Translating; Translational Regulation; Translations; Tumor Suppressor Proteins; Work; cancer care; cancer stem cell; cell motility; cofactor; cytokine; epithelial to mesenchymal transition; experimental study; in vivo; in vivo bioluminescence imaging; inhibitor/antagonist; interest; knock-down; mortality; neoplastic cell; new therapeutic target; novel; novel therapeutics; overexpression; public health relevance; 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，称为癌症干细胞 (CSC) 的原发性乳腺癌细胞的特定子集会导致转移性生长 (1)。研究表明，经历 TGF-β 诱导的上皮间质转化 (EMT) 的细胞具有 CSC 特性 (2)。由于传统化疗无法根除 CSC，阐明 TGF-β 诱导 CSC 形成的分子机制可能有助于针对 CSC 进行靶向治疗，并为癌症治疗提供范式转变。 TGF-β 诱导 EMT 的方式之一是肿瘤抑制因子 hnRNP-E1 (3-5)。在正常情况下，hnRNP-E1 结合并抑制 EMT 相关 mRNA 的翻译，但 TGF-β 治疗会从 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，因此我们想了解赋予 CSC 特性的 TGF-β/hnRNP-E1 下游效应子。我们首先关注受 TGF-β 和 hnRNP-E1 调节的基因，并选择了细胞因子白细胞介素样 EMT 诱导剂 (ILEI)。初步结果表明，ILEI 对于激活 STAT3 信号传导和启动体外 CSC 形成是必要的，但还不够。我们之前的工作表明，JAK2（STAT3 信号传导的经典激活剂）与 ILEI 受相同的 TGF-β/hnRNP-E1 机制调节。这些发现使我们推测 ILEI 需要额外的 TGF-β/hnRNP-E1 调节基因（例如 JAK2）来磷酸化 STAT3 并启动 CSC 形成。这一假设将通过以下具体目标得到解决。目标 1 将确定 TGF-β 和 hnRNP-E1 在 JAK2 表达中的作用。多核糖体分析和 RNA 免疫沉淀将确认 JAK2 是否受 hnRNP-E1 翻译调节。目标 2 将确定 JAK2 在 ILEI 信号传导中的作用。 JAK2 将在几种细胞系中受到调节，我们将测量其对 STAT3 激活以及乳腺球形成的影响。目标 3 将验证 ILEI 信号传导在 CSC 形成中的体内重要性。我们对 CSC 感兴趣是因为它们在转移性生长中的假定作用。因此，在我们的最终目标中，我们将使用小鼠乳腺癌转移模型并应用 JAK 抑制剂鲁索替尼来阻断 ILEI 信号传导。这些目标将支持将 ILEI 信号作为针对转移性乳腺癌的新型疗法。