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: 9452037
• 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/9452037
• 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; 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、增殖和分化，其失调在癌症进展和纤维化中发挥显着作用。在癌症中，TGF-β信号传导增强可促进上皮可塑性反应，进而进展为上皮-间质转化（EMT），这是由基因表达重编程驱动的，其特点是上皮细胞-细胞连接的丧失和顶端-基底极性、细胞骨架重组、额-后极性和运动性增加，这些通常会导致侵袭。由于 TGF-β 信号传导增加，部分或完全 EMT 与细胞侵袭和癌症扩散增加以及癌症产生癌症干细胞有关。 TGF-β 与两种类型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，进而激活 Smad 信号传导，同时还启动 Erk MAPK 和 PI3K-Akt 通路信号传导。 Smad 介导的基因表达以及 Erk MAPK 和 PI3K-Akt 通路信号传导的变化对于 EMT 的进展至关重要。将接头蛋白 ShcA（以两种功能形式生成，即 p52ShcA 和 p66ShcA）募集到激活的 TβRI，并通过 Tyr 上的 TβRI 对 ShcA 进行磷酸化，启动 TGF-β 诱导的 Erk MAPK 激活。然而，TβRI 主要在 Ser 上磷酸化 ShcA，但 TGF-β 诱导的 ShcA Ser 磷酸化的作用尚不清楚。 通过剖析 TGF-β 诱导的 EMT 的控制，我们发现主要表达为 p52ShcA 的 ShcA 下调，通过增加自分泌 TGF-β/Smad 信号传导导致 EMT。此外，p52ShcA 与 Smad3 竞争与 TβRI 的结合，并帮助定义 TGF-β 受体在网格蛋白相关的 Smad 激活复合物和小凹复合物之间的分布，其中 p52ShcA 将 TGF-β 受体招募到后者。因此，通过其抑制自分泌 TGF-β/Smad 反应的能力，ShcA 可以保护上皮细胞免受 EMT 影响，并有助于维持上皮完整性。我们现在提出了一项旨在确定 ShcA 在平衡 TGF-β 受体空间分布中的核心作用的计划 复合物和差异 TGF-β 信号反应，通过 TGF-β 信号传导控制 ShcA 功能，并因此了解其通过控制 TGF-β 信号传导在控制上皮可塑性、细胞侵袭、癌症干细胞生成和癌症进展中的作用。为了实现这些目标，我们建议（1）定义p52ShcA和p66ShcA在TGF-β受体的差异分布和信号传导以及TβRI稳定性和SUMO化中的作用，（）定义ShcA Ser磷酸化在TGF-β诱导的信号反应中的作用，（3）研究ShcA在上皮可塑性、细胞侵袭、癌症干细胞的调节中的作用 TGF-β信号传导的特性和肿瘤进展。我们的结果将有助于了解 ShcA 在控制 TGF-β 信号传导、癌细胞行为和癌症进展中的作用，这可能会导致找到稳定上皮表型并防止上皮可塑性反应的方法，从而促进癌症进展和扩散。