Dissecting the opposing roles of alpha-3 integrin in metastasis

剖析 α-3 整合素在转移中的相反作用

• 批准号: 7729089
• 负责人: Christopher S. Stipp
• 金额: $ 30.91万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7729089
• 关键词: Adherence; Adherens Junction; Adhesions; Amplifiers; Animal Model; Antibodies; Attention; Basement membrane; Biochemistry; Biological Assay; Breast Carcinoma; Cadherins; Carcinoma; Cardiomyopathies; Cell Adhesion; Cell Communication; Cell physiology; Cell-Cell Adhesion; Cells; Cellular biology; Clinical; Complex; Data; E-Cadherin; ERBB2 gene; Endothelial Cells; Epithelial Cells; Equilibrium; Event; Extravasation; Future; Glioma; Glycoproteins; Goals; Health; Human; In Vitro; Integrin alpha3; Integrins; Intercellular Junctions; Knockout Mice; Ligand Binding; Link; Literature; Lung; Malignant Epithelial Cell; Malignant Neoplasms; Mediating; Methods; Modeling; Monomeric GTP-Binding Proteins; Neoplasm Metastasis; Pathology; Phenotype; Play; Polycystic Kidney Diseases; Primary Neoplasm; Process; Property; Protein Family; Proteins; Publishing; RNA Interference; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Research; Role; Signal Transduction; Site; Staging; System; Testing; Tetanus Helper Peptide; Therapeutic; Tissues; Tumor Biology; Tumor Cell Invasion; Variant; Work; base; cancer therapy; cell motility; design; fibrosarcoma; host neoplasm interaction; human PHEMX protein; in vivo; inhibitor/antagonist; innovation; keratinocyte; laminin-10; laminin-5; loss of function; malignant breast neoplasm; melanoma; member; migration; neoplastic cell; novel; promoter; public health relevance; receptor; research study; src-Family Kinases; tegrin; therapeutic target; treatment strategy; tumor; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): The role of a3b1 integrin in malignancy is complex: while some studies have indicated a tumor suppressive role, many others have shown that a3b1 is a potent promoter of tumor cell adhesion, motility and invasion. This paradox may be reconciled by the fact that, in addition to a3b1's ability to mediate rapid migration on laminin-5, it can also transduce signals that promote the stable organization of E-cadherin-based adherens junctions. The balance between these opposing a3b1 functions may be regulated by a3b1- associated tetraspanin proteins. In particular, the loss of tetraspanin CD9 in tumor cells is linked to enhanced metastasis in clinical and experimental studies. Despite these data, neither the a3b1 loss-of-function pheno- type nor the role of a3b1's junction-stabilizing activity has been explored in the context of tumor biology. Our long term goal is to understand how tumor-host interactions can be manipulated to inhibit tumor cell metastasis. The objectives of this application are to (i) determine the role of a3b1 integrin in regulating collective tumor cell migration, local invasion, and metastatic colonization in conjunction with, and independently of, its ability to promote adherens junction stability, and (ii) define the mechanism by which a3b1 signals to promote the stability of carcinoma cell-cell junctions. The central hypothesis is that a3b1's ability to promote tumor invasion and metastatic colonization is balanced by a3b1's ability to promote adherens junction stability by a mechanism that depends on a3b1 association with tetraspanin CD9. This hypothesis will be tested in three specific aims. The first specific aim is to determine the roles of a3b1 integrin, tetraspanin CD9, and a3b1-CD9 association in promoting carcinoma cell junctional stability. Using epidermoid and breast carcinoma cells in which we have manipulated (i) a3 or CD9 expression, (ii) a3b1-CD9 association, and (iii) a3b1 ligand binding, we will assess adherens junction organization and stability, collective cell migration, and the cellular dynamics within intact cell sheets. The second specific aim is to define the role of a3b1 integrin expression and association with CD9 in tumor invasion and metastatic colonization. We will use a novel orthotopic invasion assay for epidermal carcinoma cells and an established orthotopic model of spontaneous breast cancer metastasis to test tumor cells in which a3 integrin or CD9 expression, a3-CD9 association, or a3 ligand binding have been separately manipulated. The third specific aim is to determine the mechanism by which a3b1 signals to promote adherens junction stability. We will use our tumor cell variants together with selective inhibitors and activators of specific cytoplasmic signaling effectors identified in our preliminary experiments to determine the connection between a3b1 signaling and the resulting stabilization of adherens junctions. Collectively, the experiments in this proposal are expected to provide critical data on the function of a3b1 in metastatic colonization, and how it relates to a3b1's role as a regulator of E-cadherin. Such results may yield important information on the suit- ability of a3b1 integrin, its associated proteins, and downstream effectors as therapeutic targets in malignancy. PUBLIC HEALTH RELEVANCE: To develop more effective and efficient cancer treatments, a major goal is to identify methods for controlling metastasis without harming healthy tissue. The proposed studies are relevant to this goal because they are expected to illuminate an as yet poorly understood mechanism that regulates the ability of tumor cells to metastasize. Once we understand more about the factors that contribute to metastasis, we may be able to identify tumor-specific processes that could be therapeutically targeted.

描述（由申请人提供）：A3B1整联蛋白在恶性肿瘤中的作用很复杂：虽然一些研究表明肿瘤抑制作用，但其他许多研究表明A3B1是肿瘤细胞粘附，运动性和侵袭的有效启动子。这种悖论可能会通过以下事实来调和，除了A3B1介导层粘连蛋白5上快速迁移的能力外，它还可以传递信号，从而促进稳定的基于E-Cadherin的粘附蛋白的粘附连接。这些相反的A3B1功能之间的平衡可以由A3B1相关的四翼胺蛋白调节。特别是，在临床和实验研究中，肿瘤细胞中四叠蛋白CD9的丧失与增强的转移有关。尽管有这些数据，但在肿瘤生物学的背景下，均未探索A3B1功能丧失的现象和A3B1连接稳定活性的作用。我们的长期目标是了解如何操纵肿瘤宿主相互作用以抑制肿瘤细胞转移。该应用的目的是（i）确定A3B1整合素在调节集体肿瘤细胞迁移，局部侵袭和转移定植中的作用，并独立于其促进粘附稳定性稳定性的能力，以及（ii）定义A3B1信号来促进Carcinoloma Cell-Cell-Cell-Cell-Cell-Cell Chinctions稳定性的机制。中心假设是A3B1促进肿瘤侵袭和转移性定植的能力取决于A3B1通过依赖于A3B1与四面蛋白CD9关联的机制促进粘附连接稳定性的能力。该假设将以三个特定目的进行检验。第一个具体目的是确定A3B1整联蛋白，四叠蛋白CD9和A3B1-CD9关联在促进癌细胞连接稳定性中的作用。使用我们操纵的表皮和乳腺癌细胞（I）A3或CD9表达，（ii）A3B1-CD9关联和（iii）A3B1配体结合，我们将评估粘附连接的组织和稳定性组织和稳定性，集体细胞迁移以及完整细胞板中的细胞动力学。第二个具体目的是定义A3B1整联蛋白表达以及与CD9在肿瘤侵袭和转移定殖中的作用。我们将对表皮癌细胞的新型矫形入侵测定法和自发性乳腺癌转移的已建立的原位模型来测试肿瘤细胞，其中A3整合素或CD9表达，A3-CD9缔合或A3配体结合已被单独操纵。第三个具体目的是确定A3B1信号促进粘附连接稳定性的机制。我们将使用我们的肿瘤细胞变体以及在我们的初步实验中鉴定的特定细胞质信号效应子的选择性抑制剂和活化剂，以确定A3B1信号传导与粘附连接的稳定稳定之间的联系。总的来说，该提案中的实验有望提供有关A3B1在转移性定植中功能的关键数据，以及它与A3B1作为E-钙粘蛋白调节剂的作用的关系。这样的结果可能会产生有关A3B1整合素，其相关蛋白质和下游效应子作为恶性靶标的适应能力的重要信息。公共卫生相关性：为了开发更有效，更有效的癌症治疗方法，一个主要目标是确定控制转移的方法而不会损害健康组织。拟议的研究与该目标有关，因为它们应阐明一种尚未了解的机制，可以调节肿瘤细胞转移的能力。一旦我们更多地了解导致转移的因素，我们就可以识别可以针对治疗靶向的肿瘤特异性过程。