Identifying the Mechanisms Governing Mena-Induced Tumor Cell Dissemination

确定 Mena 诱导的肿瘤细胞传播的控制机制

• 批准号: 8366273
• 负责人: Minna Roh
• 金额: $ 5.22万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8366273
• 关键词: Accounting; Actins; Affect; Alternative Splicing; Apoptotic; Behavior; Biological Assay; Blocking Antibodies; Blood Vessels; Cancer Etiology; Cells; Cessation of life; Chemotactic Factors; Chemotaxis; Coupled; Data; Development; Early identification; Endothelial Cells; Environment; Epidermal Growth Factor; Event; Extracellular Matrix; Family; Gene Expression Profile; Goals; Hand; Heregulin; Immunohistochemistry; In Vitro; Knowledge; Laser Scanning Confocal Microscopy; Lead; Length; Life; Light; Malignant Epithelial Cell; Malignant Neoplasms; Mammary Neoplasms; Microscopy; Migration Assay; Mind; Molecular; Movement; Needles; Neoplasm Metastasis; Patients; Phenotype; Play; Process; Protein Isoforms; Proteins; Role; Signal Pathway; Signal Transduction; Source; Specificity; System; Testing; United States; Work; base; cell motility; cell type; cellular imaging; design; high risk; in vivo; insight; macrophage; member; migration; neoplastic cell; novel marker; research study; response; tumor; vasodilator-stimulated phosphoprotein

DESCRIPTION (provided by applicant): More than 1 in 3 people will develop cancer in their lifetime, and approximately 1,500 people die from cancer each day in the United States. Metastases, which require invasion and intravasation, are the major causes of cancer-related deaths. Key cytoskeletal, proliferative and apoptotic proteins have been shown to dynamically alter their gene expression patterns during cell invasion and intravasation, suggesting their involvement in regulating some or all of the processes involved in these cell migration phenotypes. These proteins have been termed collectively as the "Invasion Signature". One of the components of the "Invasion Signature" is Mena, a member of the Enabled (Ena)/vasodilator-stimulated phosphoprotein (VASP) family. Ena/VASP proteins are highly conserved regulators of actin dynamics, known to play critical roles in cell migration. Ena/VASP proteins contain several conserved domains that are thought to elicit specificity of Mena function through alternative splicing. Expression of a Mena isoform, MenaINV, sensitizes carcinoma cells to epidermal growth factor (EGF)- induced carcinoma cell invasion and metastasis. In response to lower levels of EGF, expression of MenaINV leads to enhanced metastasis in vivo. Furthermore, expression of MenaINV results in directional movement of carcinoma cells toward blood vessels, increased invadopodium stability, and a 200-fold increase in transendothelial migration (TEM). Expression of another Mena isoform, Mena11a, also results in increased tumor cell migration. Therefore, Mena plays critical roles in invasion and intravasation. Although many roles for Mena in tumor cell metastasis have been discovered, the mechanisms by which Mena-expressing carcinoma cells use to carry out these functions are still unknown. Thus, we will take advantage of a simplified in vitro system for specific control of parameters, as well as an in vivo system developed in our lab to take into account the tumor microenvironment. With these approaches in hand, specifically, I will test the requirement of invadopodia during Mena-induced chemotaxis, invasion and intravasation, and the upstream signaling events that regulate these processes. In particular, I propose the following aims: 1) Determining whether Mena isoform-expressing cells can autonomously chemosense a chemoattractant, and what step(s) of invadopodium formation is critical for chemosensing; 2) Investigating the relationship between Mena-induced chemotaxis and invadopodium formation in vivo; and 3) Identifying the mechanism underlying the 200 fold increase in TEM activity in MenaINV-expressing cells. Ultimately, these experiments will provide insight into the mechanisms governing the observed Mena-induced metastasis in vivo, which may be critical to the development of new anti-metastatic therapies.

描述（由申请人提供）：超过三分之一的人一生中会患上癌症，在美国每天约有 1,500 人死于癌症。需要侵袭和内渗的转移是癌症相关死亡的主要原因。关键的细胞骨架、增殖和凋亡蛋白已被证明在细胞侵袭和内渗过程中动态改变其基因表达模式，表明它们参与调节这些细胞迁移表型的部分或全部过程。这些蛋白质被统称为“入侵特征”。 “入侵特征”的组成部分之一是 Mena，它是启用 (Ena)/血管舒张刺激磷蛋白 (VASP) 家族的成员。 Ena/VASP 蛋白是高度保守的肌动蛋白动力学调节因子，已知在细胞迁移中发挥关键作用。 Ena/VASP 蛋白含有几个保守结构域，这些结构域被认为可以通过选择性剪接引发 Mena 功能的特异性。 Mena 异构体 MenaINV 的表达使癌细胞对表皮生长因子 (EGF) 诱导的癌细胞侵袭和转移敏感。响应较低水平的 EGF，MenaINV 的表达导致体内转移增强。此外，MenaINV 的表达导致癌细胞向血管定向移动，增加侵袭伪足的稳定性，并使跨内皮迁移 (TEM) 增加 200 倍。另一种 Mena 异构体 Mena11a 的表达也会导致肿瘤细胞迁移增加。因此，Mena 在侵袭和内渗中起着至关重要的作用。尽管已发现 Mena 在肿瘤细胞转移中的许多作用，但表达 Mena 的癌细胞用于执行这些功能的机制仍不清楚。因此，我们将利用简化的体外系统来具体控制参数，以及我们实验室开发的体内系统来考虑肿瘤微环境。具体来说，有了这些方法，我将测试 Mena 诱导的趋化性、侵袭和内渗过程中侵袭伪足的需求，以及调节这些过程的上游信号事件。我特别提出以下目标：1）确定表达 Mena 亚型的细胞是否可以自主化学感应化学引诱剂，以及入侵伪足形成的哪些步骤对于化学感应至关重要； 2）研究Mena诱导的趋化性与体内侵入足形成的关系； 3) 确定 MenaINV 表达细胞中 TEM 活性增加 200 倍的机制。最终，这些实验将深入了解控制所观察到的 Mena 诱导的体内转移的机制，这对于开发新的抗转移疗法可能至关重要。