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（由申请人提供）：胰腺导管腺癌（PDAC）是最致命的恶性肿瘤之一，中位生存时间不到一年。高达95%的患者在诊断时存在激活KRas突变，92%的早期胰腺上皮内肿瘤已经存在突变。此外，PDAC除了远端转移之外还显示出快速的局部侵袭，这是需要对治疗靶向至关重要的多个分子事件的过程。虽然不同的PDAC细胞的侵袭模式不同（即，单细胞，集体），但侵袭区前缘的细胞可能 开发探路者细胞功能，其可以通过细胞外基质（ECM）的降解产生肿瘤细胞将扩散的微轨道。富含肌动蛋白的膜突起（侵入伪足）在特定的细胞群中发育，这导致了入侵细胞的迁移队列。因此，了解这些探路者细胞形成的机制以及在入侵边缘发生的分子动力学是至关重要的。在这些事件中，突变的KRas是形成侵袭伪足所必需的，并且需要特定的细胞支架来介导所涉及的效应器信号传导途径。例如，埃兹蛋白（一种将质膜连接到肌动蛋白细胞骨架的支架蛋白）以及埃兹蛋白-根蛋白-膜突蛋白（ERM）家族的其他成员存在于富含肌动蛋白的侵袭伪足中，并在PDAC迁移中发挥重要作用。此外，在活动PDAC的前沿和后沿的活性RhoA的离散池对于侵入行为是至关重要的。我们已经描述了一种新的抗运动性靶点（km 23 -1），其耗尽被证明可以减少Ras和ERK活性，以及TGF β 1的产生和癌细胞的运动性和侵袭性。它还与许多肌动蛋白调节蛋白相互作用，并可以调节RhoA活性和Ezrin表达。我们假设km 23 -1通过促进富含Ezrin的复合物的组装在侵袭伪足的形成和活性中起重要作用，所述复合物进一步调节Ras活性和蛋白激酶A（PKA）调节的RhoA突出-收缩事件。因此，在目的1中，我们将在代表体内环境的器官型模型中检查km 23 -1耗竭抑制PDAC侵袭的能力，所述器官型模型将包括间质胰腺星状细胞。 进一步的研究将解决km 23 -1在调节侵袭伪足RhoA活性和前导细胞迁移中的功能作用。此外，由于ERM和肌动蛋白是Ras激活所需的，我们将测试这样的假设，即在PDAC侵袭期间，km 23 -1调节Ezrin支架复合物以控制Ras激活和涉及侵袭伪足突出的下游事件。在目的2中，我们将检查km 23 -1耗尽对体内致瘤性和转移的影响，以确定km 23 -1抑制剂作为抗转移治疗的潜在效用。这些研究的结果将提供重要的新信息的空间控制Ras和RhoA活性，以及Ezrin/肌动蛋白支架，PDAC的侵袭和转移。它们还将促进开发用于治疗PDAC的新型基于km 23 -1和Ezrin的抑制剂的努力。