Central role of ShcA in differential TGF-beta signaling, epithelial plasticity and carcinoma cell behavior

ShcA 在差异 TGF-β 信号传导、上皮可塑性和癌细胞行为中的核心作用

• 批准号: 9894637
• 负责人: RIK M DERYNCK
• 金额: $ 36.26万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 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/9894637
• 关键词: AKT Signaling Pathway; Adaptor Signaling Protein; Apical; Binding; Breast Carcinoma; Cancer Control; Carcinoma; Caveolae; Cell Culture Techniques; Cell Line; Cell Maintenance; Cell physiology; Cell surface; Cells; Clathrin; Complex; Cytoskeletal Modeling; Development; Differentiation and Growth; Disease; Down-Regulation; Epithelial; Epithelial Cells; Epithelium; Equilibrium; Family; Fibrosis; Funding; Gene Activation; Gene Expression; Generations; Goals; Growth Factor; Human; Immunohistochemistry; Intercellular Junctions; Invaded; Lead; Light; Link; MAP Kinase Gene; Malignant Epithelial Cell; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Mesenchymal; Mutation Analysis; Names; Organ; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Play; Positioning Attribute; Property; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Research; Role; Signal Pathway; Signal Transduction; Spatial Distribution; Specificity; Surface; Tissues; Transforming Growth Factor beta; Transforming Growth Factor beta Receptors; autocrine; cancer cell; cancer stem cell; cell behavior; cell motility; coated pit; epithelial to mesenchymal transition; mouse ShcA protein; prevent; programs; prototype; public health relevance; receptor; recruit; response; tumor progression; tumorigenesis

 DESCRIPTION (provided by applicant): TGF-β signaling controls cell physiology, proliferation and differentiation, and its deregulation acts prominently in cancer progression and fibrosis. In carcinomas, increased TGF- signaling promotes an epithelial plasticity response that can progress to epithelial-mesenchymal transition (EMT), which is driven by reprogramming of gene expression and marked by loss of epithelial cell-cell junctions and apical-basal polarity, cytoskeletal reorganization, frontal-rear polarity and increased motility that often enables invasion. Partial or complete EMT, as a result of increased TGF-β signaling, associates with increased cell invasion and cancer dissemination, and with cancer stem cell generation by carcinomas. TGF-β binding to a cell surface complex of two types of transmembrane dual-specificity kinase receptors activates the "type I receptor" TβRI, which in turn activates Smad signaling, yet also initiates Erk MAPK and PI3K-Akt pathway signaling. Smad-mediated changes in gene expression and Erk MAPK and PI3K-Akt pathway signaling are essential for progression through EMT. Recruitment of the adaptor protein ShcA, which is generated as two functional forms, i.e. p52ShcA and p66ShcA, to the activated TβRI, and phosphorylation of ShcA by TβRI on Tyr initiate TGF-β-induced Erk MAPK activation. However, TβRI phosphorylates ShcA predominantly on Ser, but the role of TGF-β-induced Ser phosphorylation of ShcA is unknown. Dissecting the control of TGF-β-induced EMT, we found that downregulation of ShcA, expressed primarily as p52ShcA, leads to EMT through increased autocrine TGF-β/Smad signaling. Furthermore, p52ShcA competes with Smad3 for binding to TβRI and helps define the distribution of TGF-β receptors between clathrin-associated Smad activating complexes, and caveolar complexes, with p52ShcA recruiting TGF-β receptors to the latter. Thus, through its ability to repress autocrine TGF-β/Smad responses, ShcA protects epithelial cells against EMT, and helps maintain epithelial integrity. We now propose a program aimed at defining the central role of ShcA in balancing the spatial distribution of TGF-β receptor complexes and differential TGF-β signaling responses, the control of ShcA function by TGF-β signaling, and to consequently appreciate its role in controlling epithelial plasticity, cell invason, cancer stem cell generation and cancer progression, through its control of TGF-β signaling. Toward these goals, we propose (1) to define the roles of p52ShcA and p66ShcA in the differential distribution and signaling of TGF-β receptors, and TβRI stability and sumoylation, () to define the roles of ShcA Ser phosphorylation in TGF-β-induced signaling responses, (3) to study the role of ShcA in the regulation of epithelial plasticity, cell invasion, cancer stem cell properties and tumor progression by TGF-β signaling. Our results will help understand the role of ShcA in the control of TGF-β signaling, cancer cell behavior and cancer progression, which may lead to approaches to stabilize the epithelial phenotype and prevent epithelial plasticity responses that enable cancer progression and dissemination.

 描述（由申请人提供）：TGF-β信号传导控制细胞生理学、增殖和分化，其失调在癌症进展和纤维化中起重要作用。在癌中，增加的TGF-β信号传导促进上皮可塑性反应，其可以进展为上皮-间充质转化（EMT），其由基因表达的重编程驱动，并且以上皮细胞-细胞连接和顶端-基底极性的丧失、细胞骨架重组、前-后极性和增加的运动性为标志，这通常使得能够侵入。由于TGF-β信号传导增加，部分或完全EMT与增加的细胞侵袭和癌症传播以及癌的癌症干细胞产生相关。 TGF-β与两种类型的跨膜双特异性激酶受体的细胞表面复合物结合激活“I型受体”TβRI，TβRI进而激活Smad信号传导，但也启动Erk MAPK和PI 3 K-Akt通路信号传导。Smad介导的基因表达和Erk MAPK和PI 3 K-Akt通路信号传导的变化对于通过EMT的进展至关重要。TGF-β诱导的Erk MAPK激活主要是由于两种功能性的ShcA（p52 ShcA和p66 ShcA）被激活的TβRI募集，并被Tyr上的TβRI磷酸化。然而，TβRI主要在Ser上磷酸化ShcA，但TGF-β诱导的ShcA的Ser磷酸化的作用尚不清楚。 分析TGF-β诱导的EMT的控制，我们发现主要表达为p52 ShcA的ShcA的下调通过增加自分泌TGF-β/Smad信号传导导致EMT。此外，p52 ShcA与Smad 3竞争结合TβRI，并帮助确定TGF-β受体在网格蛋白相关的Smad激活复合物和小窝复合物之间的分布，其中p52 ShcA将TGF-β受体募集到后者。因此，通过其抑制自分泌TGF-β/Smad应答的能力，ShcA保护上皮细胞免受EMT，并有助于维持上皮完整性。我们现在提出一个旨在确定ShcA在平衡TGF-β受体空间分布中的中心作用的计划。 本发明的目的是为了研究TGF-β信号复合物和不同的TGF-β信号应答，通过TGF-β信号调节ShcA的功能，并因此了解其通过控制TGF-β信号在控制上皮可塑性、细胞侵袭、癌症干细胞生成和癌症进展中的作用。为此，我们提出：（1）确定p52 ShcA和p66 ShcA在TGF-β受体的不同分布和信号传导中的作用，（2）确定ShcA Ser磷酸化在TGF-β诱导的信号传导反应中的作用，（3）研究ShcA在调节上皮可塑性、细胞侵袭、通过TGF-β信号传导的癌症干细胞特性和肿瘤进展。我们的研究结果将有助于理解ShcA在控制TGF-β信号传导、癌细胞行为和癌症进展中的作用，这可能会导致稳定上皮表型和防止上皮可塑性反应的方法，从而使癌症进展和传播成为可能。