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: 8552901
• 负责人: Ira Daar
• 金额: $ 63.65万
• 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/8552901
• 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; Complex; Data; Development; Developmental Process; Disease; Disseminated Malignant Neoplasm; Distal; Embryo; Embryonic Development; Environment; Eph Family Receptors; Ephrins; Epithelial Cells; Event; Family; Family member; Fibroblast Growth Factor Receptors; Histologic; Human; Intercellular Junctions; Investigation; Laboratories; Ligands; Malignant Neoplasms; Maps; Mediating; Monomeric GTP-Binding Proteins; Morphogenesis; Movement; Neoplasm Metastasis; Neuroblastoma; Ovarian; Pathway interactions; Play; Process; Prostate; Protein Tyrosine Kinase; Proteins; Rana; Receptor Protein-Tyrosine Kinases; Research; Role; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; System; Therapeutic Intervention; Tight Junctions; Tissues; Visual Fields; Work; Xenopus; Xenopus oocyte; angiogenesis; cell motility; improved; insight; intercellular communication; interest; loss of function; lung melanoma; member; migration; mutant; neoplastic; protein complex; receptor; research study; retinal progenitor cell; tumorigenesis

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 cellcell adhesion system, which playsa crucial role in normal morphogenetic processes duringdevelopment, as well as in invasion and metastasis19. AlthoughephrinB ligands are bi-directional signalling molecules, theprecise mechanism by which ephrinB1 signals through itsintracellular domain to regulate cell-cell adhesion in epithelialcells remains unclear. Here, we present evidence that ephrinB1associates with the Par polarity complex protein Par-6 (ascaffold protein required for establishing tight junctions) andcan compete with the small GTPase Cdc42 for association withPar-6. This competition causes inactivation of the Par complex,resulting in the loss of tight junctions. Moreover, the interactionbetween ephrinB1 and Par-6 is disrupted by tyrosinephosphorylation of the intracellular domain of ephrinB1. Thus,we have identified a mechanism by which ephrinB1 signallingregulates cell-cell junctions in epithelial cells, and this mayinfluence how we devise therapeutic interventions regardingthese molecules in metastatic disease.

我们目前的研究兴趣旨在研究Eph受体酪氨酸激酶及其肝配蛋白配体信号影响细胞-细胞粘附和形态发生运动的机制。通过对这些信号转导通路的阐明，我们可以提高对肿瘤发生的认识。细胞间粘附系统在正常发育和形态发生中发挥着重要作用。这种粘附系统的失活被认为在癌症侵袭和转移中起关键作用。非洲爪蟾胚胎非常适合这些过程的调查，因为青蛙有一个很好的特点和不变的细胞命运图和细胞谱系可以很容易地在实验中跟踪。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、运动性和分化的影响可以在发育中的脊椎动物中从形态学、组织学以及生物化学上进行评估。我们的实验室目前正在研究非洲爪蟾Eph受体酪氨酸激酶和ephrinB跨膜配体在细胞信号转导和功能中的作用，使用非洲爪蟾卵母细胞和胚胎系统，以及人类培养的细胞系。目前，我们的重点放在这些Eph家族成员发送影响形态发生运动的信号的机制上。Eph家族的成员参与调节许多发育过程，并已发现在转移性癌症（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）中去调节。我们的实验室继续这些研究，检查控制细胞粘附和细胞运动的ephrinB 1的近端和远端信号。我们最近发现的证据表明，ephrinB 1信号通过其细胞内结构域控制视网膜祖细胞的运动进入视野，通过与Dishevelled（dsh）相互作用，并选择平面细胞极性（PCP）途径。使用生化分析和增益或功能丧失的实验，我们的数据表明，dsh协会与ephrinB 1和介导ephrinB 1信号通过下游成员的PCP途径在视野形成。因此，我们用眼区作为了解ephrinB 1如何控制细胞运动的模型系统，最近我们研究了ephrinB 1影响细胞-细胞连接的机制。大量的证据表明肝配蛋白配体在细胞的适当迁移以及细胞和组织边界的形成中是必需的。这些过程依赖于细胞粘附系统，其在发育期间的正常形态发生过程以及侵袭和转移中起关键作用19。虽然ephrinB配体是双向信号分子，但ephrinB 1通过其胞内结构域信号调节上皮细胞中细胞-细胞粘附的确切机制尚不清楚。在这里，我们提出的证据表明ephrinB 1与Par极性复合蛋白Par-6（一种建立紧密连接所需的caffold蛋白）相关联，并可以与小的GTdR Cdc 42竞争与Par-6的关联。这种竞争导致Par复合物的失活，导致紧密连接的丧失。此外，ephrinB 1和Par-6之间的相互作用被ephrinB 1胞内结构域的酪氨酸磷酸化破坏。因此，我们已经确定了ephrinB 1信号调节上皮细胞中细胞-细胞连接的机制，这可能会影响我们如何设计在转移性疾病中抑制这些分子的治疗干预措施。