Signaling Mechanisms of EphrinB1 in Cell Adhesion, Migration and Invasion

EphrinB1 在细胞粘附、迁移和侵袭中的信号机制

• 批准号: 8763283
• 负责人: Ira Daar
• 金额: $ 67.34万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8763283
• 关键词: Adhesions; Affect; Biochemical; Biological Models; Breast; Cancer cell line; Cell Adhesion; Cell Fate Control; Cell Line; Cell Lineage; Cell Polarity; Cell physiology; Cell-Cell Adhesion; Cells; Colon; Data; Development; Developmental Process; Disease; Disseminated Malignant Neoplasm; Distal; Ectoderm; Embryo; Embryonic Development; Environment; Eph Family Receptors; Ephrins; Epithelial Cells; Event; Family; Family member; Fibroblast Growth Factor Receptors; Germ Layers; Histologic; Human; Intercellular Junctions; Intervention; Investigation; Knowledge; Laboratories; Ligands; Maintenance; Malignant Neoplasms; Maps; Mediating; Mesoderm; Morphogenesis; Movement; Neoplasm Metastasis; Neuroblastoma; Ovarian; Pathway interactions; Play; Process; Prostate; Protein Tyrosine Kinase; Proteins; Rana; Receptor Protein-Tyrosine Kinases; Regulation; Research; Role; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; System; Tissues; Ubiquitination; Visual Fields; Work; Xenopus; Xenopus oocyte; angiogenesis; cell motility; improved; insight; intercellular communication; interest; loss of function; lung melanoma; member; migration; mutant; neoplastic; prevent; receptor; research study; retinal progenitor cell; tumor progression; tumorigenesis; ubiquitin ligase

Our current research interests are aimed toward examining the mechanism by which Eph receptor tyrosine kinases and their ephrin ligands signal events affecting cell-cell adhesion and morphogenetic movements. From the elucidation of these signal transduction pathways we may improve our understanding of oncogenesis. The cell-cell adhesion system plays a major role in normal development and morphogenesis. Inactivation of this adhesion system is thought to play a critical role in cancer invasion and metastasis. The Xenopus embryo is well suited for investigations of these processes because the frog has a well characterized and invariant cell fate map and cell lineage can be easily traced during experiments. Mutant receptors, ligands, and other proteins can be ectopically expressed in embryos. Thus, their effects on signal transduction, motility, and differentiation can be assessed morphologically and histologically as well as biochemically in a developing vertebrate. Our laboratory is currently investigating the role of the Xenopus Eph receptor tyrosine kinases and ephrinB transmembrane ligands in cell signaling and function using the Xenopus oocyte and embryo systems, as well as human cultured cell lines. At present, our emphasis is placed upon the mechanism by which these Eph family members send signals affecting morphogenetic movements. Members of the Eph family have been implicated in regulating numerous developmental processes and have been found to be de-regulated in metastatic cancers, for example, prostate, ovarian, breast, colon, neuroblastoma, lung, and melanoma. Our laboratory has continued these studies examining proximal and distal signaling from ephrinB1 that controls cell adhesion and cell movement. We recently found evidence that ephrinB1 signals via its intracellular domain to control retinal progenitor movement into the eye field by interacting with Dishevelled (dsh), and co-opting the planar cell polarity (PCP) pathway. Using biochemical analysis and gain or loss of function experiments, our data suggest that dsh associates with ephrinB1 and mediates ephrinB1 signaling via downstream members of the PCP pathway during eye field formation. thus, we have used the eye field as a model system for understanding how ephrinB1 controls cell movement. Most recently we have examined the mechanisms by which ephrinB1 affects cell-cell junctions. A body of evidence is emerging that shows a requirement for ephrin ligands in the proper migration of cells, and the formation of cell and tissue boundaries. These processes are dependent on the cell cell adhesion system, which plays a crucial role in normal morphogenetic processes during development, as well as in invasion and metastasis19. Although ephrinB ligands are bi-directional signalling molecules, the precise mechanism by which ephrinB1 signals through its intracellular domain to regulate cell-cell adhesion in epithelial cells remains unclear. Here, we demonstrate that the Smurfs regulate tissue separation at mesoderm/ectoderm boundaries through antagonistic interactions with ephrinB1, an Eph receptor ligand that has a key role in regulating the separation of embryonic germ layers. EphrinB1 is targeted by Smurf2 for degradation; however, a Smurf1 interaction with ephrinB1 prevents the association with Smurf2 and precludes ephrinB1 from ubiquitination and degradation, since it is a substantially weaker substrate for Smurf1. Inhibition of Smurf1 expression in embryonic mesoderm results in loss of ephrinB1-mediated separation of this tissue from the ectoderm, which can be rescued by the coincident inhibition of Smurf2 expression. This system of differential interactions between Smurfs and ephrinB1 regulates the maintenance of tissue boundaries through the control of ephrinB protein levels.We believe that these findings significantly broaden our concept and knowledge of the Smurf ubiquitin ligases and ephrinB regulation that affects tissue repulsion and border maintenance during embryogenesis. Furthermore, since both ephrinBs and Smurfs have been strongly implicated in cancer progression, this work may have implications when considering interventions regarding these molecules in metastatic disease.

我们目前的研究兴趣是研究Eph受体酪氨酸激酶及其ePhin配体信号影响细胞-细胞黏附和形态发生运动的机制。通过对这些信号转导途径的阐明，可以提高我们对肿瘤发生的认识。细胞-细胞黏附系统在正常发育和形态发生中起着重要作用。这种黏附系统的失活被认为在癌症的侵袭和转移中起着关键作用。非洲爪蛙胚胎非常适合研究这些过程，因为这种青蛙有一个很好的特征和不变的细胞命运图，而且在实验期间很容易追踪到细胞谱系。突变的受体、配体和其他蛋白质可以在胚胎中异位表达。因此，它们对信号转导、运动和分化的影响可以在发育中的脊椎动物中从形态和组织学以及生化方面进行评估。我们的实验室目前正在利用非洲爪哇的卵母细胞和胚胎系统以及人类培养的细胞系来研究非洲爪哇Eph受体酪氨酸激酶和eparinB跨膜配体在细胞信号和功能中的作用。目前，我们的重点放在这些Eph家族成员发出影响形态发生运动的信号的机制上。Eph家族成员参与了许多发育过程的调控，并被发现在转移性癌症中表达下调，例如前列腺癌、卵巢癌、乳腺癌、结肠癌、神经母细胞瘤、肺癌和黑色素瘤。我们的实验室继续进行这些研究，检测控制细胞黏附和细胞运动的ewitinB1的近端和远端信号。我们最近发现有证据表明，ewitinB1信号通过其细胞内结构域与Disheveled(Dsh)相互作用，并选择平面细胞极性(PCP)途径来控制视网膜前体细胞进入眼场。利用生化分析和功能得失实验，我们的数据表明，在眼场形成过程中，dsh与ewitinB1联系在一起，并通过PCP通路的下游成员介导ewitinB1信号传递。因此，我们使用眼场作为一个模型系统来理解ewitinB1是如何控制细胞运动的。最近，我们研究了ewitinB1影响细胞-细胞连接的机制。大量证据表明，在细胞的正常迁移以及细胞和组织边界的形成过程中，需要有肾上腺素配体。这些过程依赖于细胞黏附系统，细胞黏附系统在发育过程中的正常形态发生过程以及侵袭和转移过程中起着至关重要的作用。虽然ewitinB配体是双向信号分子，但ewitinB1信号通过其胞内结构域调节上皮细胞细胞间黏附的确切机制尚不清楚。在这里，我们证明了蓝精灵通过与Eph1受体配体的拮抗相互作用来调节中胚层/外胚层边界的组织分离，Eph受体配体在调节胚胎胚层的分离方面具有关键作用。E蛋白B1是S-2降解的靶标；然而，S-1与E蛋白B1的相互作用阻止了与S-B的结合，并阻止了E-B 1的泛素化和降解，因为它是S-1的一个相当弱的底物。抑制胚胎中胚层中SMurf1的表达会导致eparinB1介导的该组织与外胚层分离的丧失，这可以通过同时抑制SMurf2的表达来挽救。我们相信，这些发现极大地拓宽了我们对蓝精灵泛素连接酶和eferinB调控的概念和认识，它们在胚胎发育过程中影响组织排斥和边界维持。此外，由于eparinB和蓝精灵都与癌症进展密切相关，这项工作可能会在考虑对转移性疾病中的这些分子进行干预时产生影响。