Vimentin Phospho-Malleability is Critical for Maintaining Stemness and Metastatic Properties

波形蛋白磷酸延展性对于维持干性和转移特性至关重要

• 批准号: 10795597
• 负责人: Sendurai Ayyavoo Mani
• 金额: $ 39.72万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10795597
• 关键词: Vimentin; Phospho; Malleability; Critical; Maintaining

Project Summary Metastasis remains a major obstacle in the treatment of breast cancer. A key contributor to metastasis is the epithelial-to-mesenchymal transition (EMT) program. During EMT, cancer cells gain mesenchymal, migratory, invasive, and stem cell properties. Cancer stem cells (CSCs) play crucial roles in metastatic progression, cancer recurrence, and chemoresistance. There is an urgent need for CSC-targeting therapies to combat recurrence and prevent metastasis. The premiere strategy to exploit the vulnerabilities of CSCs is to identify essential factors that support the stemness phenotype. Recent research has shown that the EMT process does not move cells between the binary “epithelial” and “mesenchymal” states. Instead, it is a continuum, and the cells can maintain both epithelial and mesenchymal characteristics (hybrid E/M) and possess high cellular plasticity and stemness. During EMT, changes in intermediate filaments, particularly upregulation of the mesenchymal-associated filament protein vimentin, have been documented. However, the role of vimentin in EMT and stemness and the consequence of co-expression of vimentin and cytokeratin (CK) in hybrid E/M cells with high stemness are not known. Besides, the function of vimentin is regulated through dynamic phosphorylation and dephosphorylation on critical sites, also known as “vimentin phospho-malleability. Preliminary data show that inhibiting phospho- malleability of vimentin serine-56 (S56) inhibits stemness and induces multinucleation in triple-negative breast cancer (TNBC) cells. It does not affect cancer cells with epithelial phenotypes, which do not express vimentin, or fibroblasts, which only express vimentin. Among the various phosphorylation sites, the phospho-malleability of S56 alone can induce multinucleation and inhibit stemness. Therefore, we hypothesize that vimentin S56 phospho-malleability is critical for maintaining the stemness of carcinoma cells expressing vimentin, and it is a driver of metastasis. Interfering with vimentin S56 phosphorylation will result in selective elimination of CSCs, inhibition of metastasis, and increased chemo-sensitivity. We propose the following aims to test this hypothesis: (1) Characterize how vimentin S56 phospho-malleability influences EMT and stem cell properties. (2) Define how the interaction between phospho-malleable vimentin and CK affects stemness in hybrid E/M cells with plasticity. (3) Determine the importance of vimentin S56 phospho-malleability on metastasis. Through innovative experiments using hybrid E/M cell lines, we will identify signaling pathways and vimentin-interacting proteins in the context of vimentin S56 phospho-malleability. Using patient TNBC samples, syngeneic tumor xenografts, and human patient-derived xenografts, we will demonstrate the biological importance of vimentin S56 phospho-malleability for stemness in vitro and metastasis in vivo. Understanding the importance of vimentin S56 phospho-malleability and the impact of impairing this will aid in developing novel EMT and CSC-targeting therapies to treat metastasis-prone TNBCs.

项目摘要 转移仍然是乳腺癌治疗的主要障碍。转移的一个关键因素是 上皮细胞向间充质细胞转化（EMT）程序。在EMT期间，癌细胞获得间质，迁移， 以及干细胞特性。癌症干细胞（CSC）在转移进展、癌症治疗和癌症治疗中起着至关重要的作用。 复发和耐药性。迫切需要CSC靶向治疗来对抗复发 并防止转移。利用CSC的脆弱性的首要策略是确定关键因素 支持干性表型的基因最近的研究表明，EMT过程不会移动细胞， 介于“上皮”和“间充质”之间。相反，它是一个连续体，细胞可以维持 上皮和间充质特征（混合E/M），并具有高细胞可塑性和干性。 在EMT过程中，中间丝的变化，特别是间充质相关细胞的上调， 丝蛋白波形蛋白，已经被记录。然而，波形蛋白在EMT和干性中的作用以及 在高干细胞性的E/M细胞中，波形蛋白和细胞角蛋白（CK）共表达的结果并不 知道的此外，波形蛋白的功能是通过动态磷酸化和去磷酸化来调节的 也称为“波形蛋白磷酸延展性”。初步数据显示，抑制磷酸- 波形蛋白丝氨酸-56（S56）的延展性抑制三阴性乳腺癌的干性并诱导多核化 癌症（TNBC）细胞。它不影响不表达波形蛋白的上皮表型癌细胞， 或者只表达波形蛋白的成纤维细胞。在各种磷酸化位点中， 单独使用S56可诱导多核化，抑制茎干。因此，我们假设波形蛋白S56 磷酸化延展性对于维持表达波形蛋白的癌细胞的干性是关键的， 它是肿瘤转移的驱动因素。干扰波形蛋白S56磷酸化将导致选择性的 消除CSC、抑制转移和增加化学敏感性。我们提议下列 目的是验证这一假设：（1）描述波形蛋白S56磷酸化延展性如何影响EMT和干细胞 细胞特性。(2)定义磷酸化延展性波形蛋白和CK之间的相互作用如何影响 具有可塑性的E/M细胞。(3)确定波形蛋白S56磷酸化延展性对 转移通过使用混合E/M细胞系的创新实验，我们将识别信号通路， 波形蛋白S56磷酸延展性背景下的波形蛋白相互作用蛋白。使用患者TNBC样品， 同基因肿瘤异种移植物和人类患者来源的异种移植物，我们将证明生物学 波形蛋白S56磷酸延展性对体外干性和体内转移重要性了解 波形蛋白S56磷酸延展性的重要性以及削弱这一点的影响将有助于开发新的 EMT和CSC靶向疗法治疗易转移的TNBC。