Directional Motility and ERM Scaffolding in Pathfinder Pancreatic Carcinoma Cells

Pathfinder 胰腺癌细胞的定向运动和 ERM 支架

• 批准号: 8779713
• 负责人: Kathleen M Mulder
• 金额: $ 16.64万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8779713
• 关键词: 3-Dimensional; A kinase anchoring protein; Actin-Binding Protein; Actins; Address; Adenocarcinoma Cell; Behavior; Binding; Binding Proteins; Biosensor; Cause of Death; Cell membrane; Cell physiology; Cells; Complex; Cyclic AMP-Dependent Protein Kinases; Cytoskeleton; Development; Diagnosis; Disease; Disease Progression; Distant; Distant Metastasis; Environment; Epithelial Cells; Event; Extracellular Matrix Degradation; Extracellular Matrix Proteins; Family; Fibroblasts; Fibronectins; Focal Adhesions; Growth; Human; Interphase Cell; Intraepithelial Neoplasia; Invaded; Label; Lead; Life; Link; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Membrane; Mitogen-Activated Protein Kinases; Modeling; Molecular; Mutation; Neoplasm Metastasis; Pancreas; Pancreatic Ductal Adenocarcinoma; Pancreatic carcinoma; Patients; Play; Population; Process; Production; Property; Protein Family; Proteins; Recruitment Activity; Regulation; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Site; Staging; Stress Fibers; Testing; Therapeutic; Time; Tumor Cell Invasion; Tumorigenicity; Validation; base; cancer cell; cell motility; cellular imaging; cohort; ezrin; genetic regulatory protein; in vitro Model; in vivo; in vivo Model; inhibitor/antagonist; knock-down; member; migration; moesin; molecular dynamics; mutant; neoplastic cell; novel; novel therapeutic intervention; pancreatic neoplasm; protein complex; public health relevance; radixin protein; rapid growth; rho; scaffold; stellate cell; targeted treatment; tumor; tumor growth

DESCRIPTION (provided by applicant): Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, with median survival times of less than a year. Activating KRas mutations are present at diagnosis in up to 95% of patients, with alterations already existing in 92% of early-stage pancreatic intraepithelial neoplasms. In addition, PDAC displays rapid invasion locally, in addition to distant metastasis, processes that require multiple molecular events that are critical to target therapeutically. While the mode of invasion varies among different PDAC cells (ie, single-cell, collective), cells at the leading edge of invasion zones may develop pathfinder cell functions, which can create the microtracks through which the tumor cells will spread, by degradation of the extracellular matrix (ECM). Actin-rich membrane protrusions (invadopodia) develop in specific cell populations, which lead the migratory cohort of invading cells. Thus, it is critical to understand the mechanisms involved in the formation of these pathfinder cells and the molecular dynamics that occur at the invading edges. Among these events, mutant KRas is required for the formation of invadopodia, and specific cellular scaffolds are required for mediating the effector signaling pathways involved. For example, Ezrin, a scaffold protein that links the plasma membrane to the actin cytoskeleton, as well as other members of the ezrin-radixin-moesin (ERM) family, are present in actin-rich invadopodia and play important roles in PDAC migration. In addition, discrete pools of active RhoA at the leading and lagging edges of motile PDACs are critical for invasive behavior. We have described a novel anti-motility target (km23-1), the depletion of which was shown to diminish Ras and ERK activity, as well as TGFss1 production and cancer cell motility and invasion. It also interacts with numerous actin-regulatory proteins and can modulate RhoA activity and Ezrin expression. We hypothesize that km23-1 plays an important role in the formation and activity of invadopodia by facilitating the assembly of Ezrin- enriched complexes that further regulate Ras activity and protein kinase A (PKA)-modulated RhoA protrusion- retraction events. Therefore, in Aim 1, we will examine the ability of km23-1 depletion to inhibit PDAC invasion in organotypic models representative of the in vivo setting, which will include stromal pancreatic stellate cells. Additional studies will address the functional role of km23-1 in regulating invadopodia RhoA activity and leader cell migration. Further, since ERM and actin are required for Ras activation, we will test the hypothesis that km23-1 regulates Ezrin scaffolded complexes to control Ras activation and downstream events involved in invadopodia protrusion during PDAC invasion. In Aim 2, we will examine the effect of km23-1 depletion on tumorigenicity and metastasis in vivo to determine the potential utility of km23-1 inhibitors as anti-metastatic therapy. The results of these studies will provide significant new information regarding the spatial control of Ras and RhoA activity, as well as Ezrin/actin scaffolding, in PDAC invasion and metastasis. They will also facilitate efforts to develop novel km23-1- and Ezrin-based inhibitors for the treatment of PDAC.

描述(申请人提供)：胰腺导管腺癌(PDAC)是最致命的恶性肿瘤之一，中位生存期不到一年。高达95%的患者在确诊时存在激活的KRAS突变，92%的早期胰腺上皮内肿瘤已经存在变化。此外，除了远处转移外，PDAC还表现出快速的局部侵袭，这一过程需要多个分子事件，这些事件对靶向治疗至关重要。虽然不同的PDAC细胞(即单细胞、集体)的侵袭方式不同，但侵袭区前沿的细胞可能 开发探路细胞功能，通过降解细胞外基质(ECM)来创造肿瘤细胞扩散的微轨迹。富含肌动蛋白的膜突起在特定的细胞群中发育，导致入侵细胞的迁移队列。因此，了解这些探路细胞形成的机制和发生在入侵边缘的分子动力学是至关重要的。在这些事件中，突变的KRAS是形成啮齿动物所必需的，而特定的细胞支架是调节所涉及的效应器信号通路所必需的。例如，Ezrin是一种连接质膜和肌动蛋白细胞骨架的支架蛋白，以及Ezrin-Radisin-moesin(ERM)家族的其他成员，它们存在于富含肌动蛋白的不定形体内，并在PDAC的迁移中发挥重要作用。此外，在可移动的PDAC的前沿和滞后边缘的离散的活性RhoA池对侵入性行为至关重要。我们已经描述了一种新的抗运动靶点(km23-1)，它的缺失被证明降低了RAS和ERK的活性，以及TGFss1的产生和癌细胞的运动和侵袭。它还与许多肌动蛋白调节蛋白相互作用，并能调节RhoA活性和Ezrin的表达。我们推测，km23-1通过促进富含Ezrin的复合体的组装，进一步调节Ras活性和蛋白激酶A(PKA)调节的RhoA突起-收缩事件，在内向足突的形成和活动中发挥重要作用。因此，在目标1中，我们将在代表体内环境的器官模型中检测km23-1缺失抑制PDAC侵袭的能力，其中将包括基质胰腺星状细胞。 更多的研究将涉及km23-1在调节剑尾轮虫RhoA活性和领导细胞迁移中的功能作用。此外，由于ERM和肌动蛋白是RAS激活所必需的，我们将检验这样的假设，即km23-1调节Ezrin支架复合体以控制RAS的激活和参与PDAC侵袭过程中的不对称突起的下游事件。在目标2中，我们将检测km23-1缺失在体内对肿瘤发生和转移的影响，以确定km23-1抑制剂作为抗转移治疗的潜在用途。这些研究结果将提供关于Ras和RhoA活性的空间调控以及Ezrin/肌动蛋白支架在PDAC侵袭和转移中的重要新信息。它们还将促进开发用于治疗PDAC的新型km23-1和Ezrin抑制剂的努力。