Molecular Mechanisms Of Cell Adhesion And Invasion

细胞粘附和侵袭的分子机制

• 批准号: 8336528
• 负责人: Steven Akiyama
• 金额: $ 182.32万
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 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/8336528
• 关键词: 1-Phosphatidylinositol 3-Kinase; Acute; Acute Disease; Adhesions; Adhesives; Affinity Chromatography; Animals; Autoimmunity; Automobile Driving; Basement membrane; Binding; Biological Models; Blood Platelets; Blood Vessels; Bone remodeling; CD29 Antigen; Cell Adhesion; Cell Adhesion Molecules; Cell Line; Cell Surface Receptors; Cell surface; Cell to Cell Adhesion Signaling Pathway; Cell-Cell Adhesion; Cells; Chimeric Proteins; Chronic; Chronic Disease; Collagen; Complex; Cues; Cytoskeleton; Data; Development; Disease; Disease Progression; E-Selectin; Embryo; Embryonic Development; Endogenous Factors; Endothelial Cells; Endothelium; Environmental Risk Factor; Event; Exposure to; Extracellular Matrix; Family; Fibronectins; Gelatinase B; Glycoproteins; Goals; Human; Immunoglobulin G; Inflammation; Inflammatory; Inflammatory Response; Integrin-mediated Cell Adhesion Pathway; Integrins; Intervention; L-Selectin; Laminin; Leukocyte Rolling; Leukocyte Trafficking; Leukocytes; MAP Kinase Gene; MAPK14 gene; Malignant Neoplasms; Mediating; Melanoma Cell; Membrane Glycoproteins; Membrane Proteins; Molecular; Morphogenesis; Neoplasm Metastasis; P-Selectin; Pathway interactions; Phenotype; Play; Post-Translational Protein Processing; Prevention strategy; Process; Proteins; Proteomics; Recombinants; Regulation; Research; Role; Selectins; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Site; Small Interfering RNA; Stimulus; System; Thrombin; Thrombosis; Tissues; Toxic Environmental Substances; Tyrosine Phosphorylation; Wound Healing; adhesion receptor; cell motility; design; exposed human population; extracellular; human disease; human migration; implantation; member; migration; mitogen-activated protein kinase p38; neoplastic cell; novel; nucleolin; receptor; response; tumor

Cell adhesion and migration contribute to normal processes such as differentiation, embryonic development, and wound healing as well as to the progression of diseases and pathological conditions that can result from either acute or chronic exposure to environmental toxicants, such as cancer and inflammatory responses. Key mechanistic steps in these processes involve the interactions of extracellular glycoproteins--such as fibronectin, laminin, and collagens--with specific adhesive receptors, the best characterized of which are the integrins, a family of heterodimeric complexes consisting of an alpha subunit and a beta subunit. Integrins are highly regulated receptors that can exist in either an active or inactive state. Selectins are vascular cell-cell adhesion molecules involved in leukocyte trafficking, inflammation, thrombosis, autoimmunity and cancer. Accumulation of leukocytes at sites of inflammation is initiated by selectins that mediate the capturing and rolling of leukocytes on endothelium. Three major members of the selectin family have been identified: L-selectin, E-selectin and P-selectin. L-Selectin is constitutively expressed on leukocytes. P-and E-selectins are expressed on activated endothelial cells in response to microenvirnomental stimuli. P-selectin is also expressed on thrombin-activated platelets. All three members of the selectin family, E-, L-, and P-selectin can bind to human tumor cells and cancer-derived cell line. Our research has focused recently on the possible role of cues from the tumor microenvironment that can regulate integrin-mediated tumor cell migration and invasion. As a model system, we are examining the ability of one selectin, P-selectin, to trigger integrin-mediated adhesion and migration of cultured human tumor cells. We focus on two closely related aspects of this project: to characterize the mechanisms of P-selectin-induced activation of integrin-mediated cell adhesion and cell migration. We have previously shown that binding of soluble, recombinant P-selectin-IgG Fc chimeric protein to Colo-320 cells stimulates cell adhesion to fibronectin through the specific activation of the alpha5-beta1 integrin by means of the p38 MAP kinase and PI-3 kinase (PI3-k) signaling pathways. We have now identified nucleolin as a novel cell surface P-selectin receptor on Colo-320 cells using affinity chromatography and a proteomic approach. We have also found that P-selectin binding to Colo-320 cells induces tyrosine phosphorylation specifically of cell-surface nucleolin and formation of a signaling complex containing cell surface nucleolin, PI 3-K, and p38 MAPK. Using siRNA approaches, we showed that both P-selectin binding to Colo-320 cells and formation of the P-selectin-mediated p38 MAPK/ PI 3-K signaling complex require nucleolin expression. Thus, we have characterized nucleolin (or a nucleolin-like protein) as a novel, signaling cell-surface receptor for P-selectin on Colo-320 cells and suggest a mechanism for linkage of nucleolin to P-selectin-induced signal transduction pathways that regulate the adhesion of Colo-320 on fibronectin substrates. We have recently been characterizing the stimulation of integrin-mediated tumor cell migration by the binding of soluble, recombinant P-selectin-IgG Fc chimeric protein. We have found that P-selectin stimulates the secretion of matrix metalloproteinase-9 (MMP-9) by A375 human melanoma cells and that direct addition of exogenous MMP-9 to A-375 cells can stimulate the migratory phenotype. The current paradigm in the field states that MMP-9 stimulates migration by digesting basement membrane proteins, allowing tumor cells to clear a migratory pathway. However, we have preliminary data that show that stimulation of cell migration by MMP-9 can occur even in the absence of catalytic activity.

细胞粘附和迁移有助于正常过程，例如分化、胚胎发育和伤口愈合，以及由于急性或慢性暴露于环境毒物（例如癌症和炎症反应）而导致的疾病和病理状况的进展。这些过程中的关键机制步骤涉及细胞外糖蛋白（例如纤连蛋白、层粘连蛋白和胶原蛋白）与特定粘附受体的相互作用，其中最具特征的是整合素，这是一个由 α 亚基和 β 亚基组成的异二聚体复合物家族。整合素是高度调控的受体，可以以活性或非活性状态存在。 选择素是血管细胞间粘附分子，参与白细胞运输、炎症、血栓形成、自身免疫和癌症。白细胞在炎症部位的积累是由选择素引发的，选择素介导白细胞在内皮上的捕获和滚动。 已鉴定出选择素家族的三个主要成员：L-选择素、E-选择素和P-选择素。 L-选择素在白细胞上组成型表达。 P-和E-选择素在响应微环境刺激的活化内皮细胞上表达。 P-选择素也在凝血酶激活的血小板上表达。 选择素家族的所有三个成员，E-、L-和P-选择素都可以与人类肿瘤细胞和癌症衍生细胞系结合。 我们的研究最近集中在肿瘤微环境中的线索可能发挥的作用，这些线索可以调节整合素介导的肿瘤细胞迁移和侵袭。作为一个模型系统，我们正在研究一种选择素（P-选择素）触发整合素介导的培养人类肿瘤细胞粘附和迁移的能力。我们重点关注该项目的两个密切相关的方面：表征 P-选择素诱导的整合素介导的细胞粘附和细胞迁移激活的机制。 我们之前已经证明，可溶性重组 P-选择素-IgG Fc 嵌合蛋白与 Colo-320 细胞的结合可通过 p38 MAP 激酶和 PI-3 激酶 (PI3-k) 信号通路特异性激活 α5-β1 整合素，从而刺激细胞与纤连蛋白的粘附。 我们现在使用亲和层析和蛋白质组学方法将核仁素鉴定为 Colo-320 细胞上的新型细胞表面 P-选择素受体。 我们还发现，P-选择素与 Colo-320 细胞结合可诱导细胞表面核蛋白特异性酪氨酸磷酸化，并形成含有细胞表面核蛋白、PI 3-K 和 p38 MAPK 的信号复合物。 使用 siRNA 方法，我们发现 P-选择素与 Colo-320 细胞的结合以及 P-选择素介导的 p38 MAPK/PI 3-K 信号复合物的形成都需要核仁素的表达。因此，我们将核仁素（或核仁素样蛋白）描述为 Colo-320 细胞上 P-选择素的新型信号传导细胞表面受体，并提出了核仁素与 P-选择素诱导的信号转导途径的连接机制，该途径调节 Colo-320 在纤连蛋白基质上的粘附。 我们最近一直在研究通过可溶性重组 P-选择素-IgG Fc 嵌合蛋白的结合来刺激整合素介导的肿瘤细胞迁移。 我们发现P-选择素刺激A375人黑色素瘤细胞分泌基质金属蛋白酶9（MMP-9），并且直接向A-375细胞添加外源MMP-9可以刺激迁移表型。 该领域当前的范例表明，MMP-9 通过消化基底膜蛋白来刺激迁移，从而使肿瘤细胞能够清除迁移途径。 然而，我们的初步数据表明，即使在没有催化活性的情况下，MMP-9 也会刺激细胞迁移。