Deciphering molecular mechanisms of Epithelial Plasticity

解读上皮可塑性的分子机制

• 批准号: 10533831
• 负责人: Emily Nicole Arner
• 金额: $ 9.27万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10533831
• 关键词: AKT3 gene; Automobile Driving; Binding; Biological Assay; Cancer Biology; Cancer Etiology; Cell Line; Cell Survival; Cells; Cessation of life; Chemoresistance; Chronic; DNA Repair; DNA Sequence Alteration; Data; Development; Disseminated Malignant Neoplasm; Distant; Epithelium; Exhibits; Fibroblasts; Gene Amplification; Genetic Transcription; Glioma; Goals; Human; Immunofluorescence Immunologic; Immunoprecipitation; Invaded; KRAS2 gene; Location; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Mesenchymal; Molecular; Mutation; Neoplasm Metastasis; Oncogenes; Organ; Organoids; Pancreatic Ductal Adenocarcinoma; Paracrine Communication; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Postdoctoral Fellow; Process; Prognosis; Protein Isoforms; Proteins; Proto-Oncogene Proteins c-akt; Publishing; Receptor Protein-Tyrosine Kinases; Relapse; Research; Resistance; Role; TANK-binding kinase 1; Techniques; Technology; Therapeutic; Tissues; Work; axl receptor tyrosine kinase; cancer cell; cancer therapy; cancer type; cell motility; combat; effective therapy; epithelial to mesenchymal transition; experimental study; gain of function; in vivo; loss of function; malignant breast neoplasm; migration; mutant; neoplastic cell; novel; novel strategies; pancreatic cancer cells; pancreatic ductal adenocarcinoma cell; pharmacologic; programs; protein expression; response; single cell sequencing; slug; transcription factor; tumor; tumor microenvironment; tumor progression; tumorigenesis

Project Summary/Abstract Cellular plasticity, a feature associated with epithelial-to-mesenchymal transition (EMT), contributes to tumor cell survival, migration, invasion, and therapy resistance. Across human cancer, tumors that are high grade, poorly differentiated, and have undergone EMT carry a worse prognosis with a high likelihood of metastasizing to distant organs. EMT is a common feature associated with tumor progression and is thought to be critical to cancer cell dissemination in some tumors, such as pancreatic ductal adenocarcinoma (PDA). PDA is a lethal and poorly understood human malignancy that is characterized by an activating mutation in KRAS. Additionally, AXL, a receptor tyrosine kinase (RTK), has been implicated in tumor progression, metastasis, therapy resistance, and EMT in multiple cancer types including PDA. During my dissertation studies, I have found that TANK-binding kinase 1 (TBK1), a critical downstream effector of mutant active KRAS, is central to AXL-driven EMT in KRAS-mutant PDA. However, the mechanism of how TBK1 drives EMT has yet to be elucidated. We hypothesize that TBK1 drives EMT via activation of AKT3 and the stability of downstream transcriptional networks. My data demonstrate that AKT3 is activated downstream of TBK1 in response to stimulation of AXL, which leads to the binding of AKT3 and Slug in an AXL-TBK1 dependent manner. To complete my dissertation, I will establish the function of AKT3 in driving EMT downstream of Axl and TBK1 with the following goals: 1) Establish the necessity of AKT3 for Axl and TBK1 driven EMT; 2) Evaluate EMT transcription factors engaged downstream of TBK1 and 3) Determine the effect of AKT3 activation on the stability of EMT transcription factors. Despite significant evidence that EMT directly contributes to tumor progression, several studies have suggested EMT is not required for the metastatic spread of PDA and breast cancer. For example, most metastatic lesions are known to exhibit epithelial features, an observation that seems to be at odds with EMT as a prerequisite for metastasis. As such, the importance of EMT in cancer biology h as been questioned. I hypothesize that the chronic activation of an EMT program within a tumor may depend on paracrine signals within the tumor microenvironment, dictating whether the tumor cells undergo EMT or MET. Because these cells exist in a plastic state, it is possible that these tumor cells readily revert their phenotype based on a microenvironment-specific context and factors. Additionally, current in vivo lineage- tracing technology has not settled the debate between the importance of collective m igration and/or EMT for metastatic dissemination. During my postdoctoral research, I aim to investigate the role of EMT in metastasis using in vivo lineage tracing, single-cell sequencing, and organoids to better understand epithelial plasticity in an oncogene- and tissue-specific manner. Understanding this process will aid in the development of effective metastatic cancer therapies and will direct future research directions in metastasis.

项目概要/摘要 细胞可塑性是与上皮间质转化 (EMT) 相关的一个特征，有助于 肿瘤细胞的存活、迁移、侵袭和治疗抵抗。在人类癌症中，肿瘤发病率很高 分级、低分化且已接受 EMT 的预后较差，很可能出现以下情况： 转移至远处器官。 EMT 是与肿瘤进展相关的一个常见特征，被认为 对某些肿瘤（例如胰腺导管腺癌）中的癌细胞传播至关重要 （掌上电脑）。 PDA 是一种致命且人们知之甚少的人类恶性肿瘤，其特点是激活 KRAS 突变。此外，AXL，一种受体酪氨酸激酶 (RTK)，与肿瘤有关 包括 PDA 在内的多种癌症类型的进展、转移、治疗耐药和 EMT。在我的 在论文研究中，我发现 TANK 结合激酶 1 (TBK1) 是 突变活性 KRAS 是 KRAS 突变 PDA 中 AXL 驱动的 EMT 的核心。然而，其机制如何 TBK1 驱动 EMT 的机制尚未阐明。我们假设 TBK1 通过激活 AKT3 驱动 EMT 以及下游转录网络的稳定性。我的数据表明 AKT3 已激活 TBK1 下游响应 AXL 刺激，导致 AKT3 和 Slug 结合 AXL-TBK1依赖方式。为了完成我的论文，我将建立 AKT3 在驱动 EMT 中的功能 Axl 和 TBK1 的下游，目标如下： 1) 确定 AKT3 对于 Axl 和 TBK1 驱动的必要性 急救人员； 2) 评估参与 TBK1 下游的 EMT 转录因子，3) 确定 AKT3 的作用 激活对EMT转录因子稳定性的影响。 尽管有大量证据表明 EMT 直接促进肿瘤进展，但多项研究表明 建议 PDA 和乳腺癌的转移性扩散不需要 EMT。例如，大多数 已知转移性病变表现出上皮特征，这一观察结果似乎与 EMT作为转移的先决条件。因此，EMT 在癌症生物学中的重要性已被人们所认识。 质疑。我推测肿瘤内 EMT 程序的慢性激活可能取决于 肿瘤微环境中的旁分泌信号，决定肿瘤细胞是否经历 EMT 或 MET。由于这些细胞以可塑状态存在，因此这些肿瘤细胞可能很容易恢复其状态 基于微环境特定背景和因素的表型。此外，目前的体内谱系- 追踪技术尚未解决集体移民和/或紧急医疗救护的重要性之间的争论 用于转移性播散。在我的博士后研究期间，我的目标是研究 EMT 在 使用体内谱系追踪、单细胞测序和类器官更好地了解转移 以癌基因和组织特异性方式上皮可塑性。了解这个过程将有助于 开发有效的转移性癌症疗法并将指导转移的未来研究方向。