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: 8128222
• 负责人: Minna Roh
• 金额: $ 4.84万
• 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/8128222
• 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; 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; Pattern; 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. PUBLIC HEALTH RELEVANCE: 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. Early identification of cancer, and knowledge about the metastatic potential of a tumor may facilitate treatment, and thus increase survival. With this work, we hope to understand the molecular basis of tumor cell spread, with the goal of uncovering new markers to identify high-risk patients and ultimately develop new anti-metastatic therapies.

描述（由申请人提供）：超过三分之一的人在其一生中会患上癌症，在美国每天大约有1500人死于癌症。需要侵袭和体内转移的转移是癌症相关死亡的主要原因。关键的细胞骨架蛋白、增殖蛋白和凋亡蛋白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”的一个组成部分是Mena，它是启用(Ena)/血管扩张剂刺激磷酸化蛋白（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，已知在细胞迁移中起关键作用。Ena/VASP蛋白包含几个保守结构域，这些结构域被认为通过选择性剪接引发Mena功能的特异性。Mena亚型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。在EGF水平降低的情况下，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方向移动，增加了血管内稳定性，并使跨内皮迁移（TEM）增加了200倍。另一种Mena亚型Mena11a的表达也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。虽然已经发现了Mena在肿瘤细胞转移中的许多作用，但表达Mena的癌细胞使用这些功能的机制仍然未知。因此，我们将利用简化的体外系统来特定控制参数，以及我们实验室开发的体内系统来考虑肿瘤微环境。有了这些方法，具体来说，我将测试在mena诱导的趋化、侵袭和内渗过程中侵入性的需求，以及调节这些过程的上游信号事件。具体而言，我提出以下目标：1)确定表达Mena亚型的细胞是否能够自主地化学感应化学引诱剂，以及入侵细胞形成的哪个步骤对化学感应至关重要；2)研究mena诱导的趋化性与体内侵入过继体形成的关系；3)确定表达menainv的细胞中TEM活性增加200倍的机制。最终，这些实验将为观察到的mena诱导的体内转移的机制提供见解，这可能对开发新的抗转移疗法至关重要。