Molecular Mechanisms Of Cell Adhesion And Invasion

细胞粘附和侵袭的分子机制

• 批准号: 8734055
• 负责人: Steven Akiyama
• 金额: $ 89.78万
• 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/8734055
• 关键词: Acute; Acute Disease; Adhesions; Adhesives; Animals; Arachidonic Acids; Automobile Driving; Basement membrane; Binding; Biological Models; Bone remodeling; Breast Carcinoma; CD29 Antigen; Cell Adhesion; Cell to Cell Adhesion Signaling Pathway; Cell-Cell Adhesion; Cells; Chimeric Proteins; Chronic; Chronic Disease; Collagen; Collagen Type IV; Complex; Cues; Cytoskeleton; Data; Development; Disease; Disease Progression; Embryo; Embryonic Development; Endogenous Factors; Environmental Risk Factor; Event; Exposure to; Extracellular Matrix; Family; Fatty Acids; Fibronectins; Fluorescence; Focal Adhesions; Glycoproteins; Goals; Human; Image; Inflammation; Inflammatory; Inflammatory Response; Integrin-mediated Cell Adhesion Pathway; Integrins; Intervention; Laminin; Lead; MAPK14 gene; Malignant Epithelial Cell; Malignant Neoplasms; Mediating; Membrane Glycoproteins; Microfilaments; Molecular; Morphogenesis; Neoplasm Metastasis; P-Selectin; Play; Post-Translational Protein Processing; Prevention strategy; Process; Protein Kinase; Proteins; Pseudopodia; Regulation; Research; Role; Selectins; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Stress Fibers; System; Tissues; Toxic Environmental Substances; Vinculin; Wound Healing; adhesion receptor; cell motility; design; exposed human population; extracellular; human MAPK14 protein; human disease; implantation; migration; neoplastic cell; receptor; tumor microenvironment

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. 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. Arachidonic acid stimulates cell adhesion by activating alpha2-beta1 integrins in a process that depends on protein kinases, including p38 mitogen activated protein kinase. We have investigated the interaction of cytoskeletal components with key signaling molecules that contribute to spreading of, and morphological changes in, arachidonic acid-treated MDA-MB-435 human breast carcinoma cells. Arachidonic acid-treated cells showed increased attachment and spreading on collagen type IV. Fatty acid-treated cells displayed short cortical actin filaments associated with an increased number of beta1 integrin-containing pseudopodia whereas untreated cells displayed elongated stress fibers and fewer clusters of beta1 integrins. Vinculin and phospho-p38 both appeared to be enriched in pseudopodia and at the tips of actin filaments arachidonic acid-treated cells.Fluorescence ratio imaging indicated the increase was specific for the phospho-(active) form of p38. Immunoprecipitates of phospho-p38 from extracts of arachidonic acid-treated cells contained vinculin, and GST-vinculin fusion proteins carrying the central region of vinculin bound phospho-p38, whereas fusion proteins expressing the terminal portions of vinculin did not. These data suggest that phospho-p38 associates with particular domains on critical focal adhesion proteins that are involved in tumor cell adhesion and spreading and that this association can be regulated by factors in the tumor microenvironment.

细胞粘附和迁移有助于正常过程，如分化、胚胎发育和伤口愈合，以及可能由急性或慢性暴露于环境毒物引起的疾病和病理状况的进展，如癌症和炎症反应。这些过程中的关键机制步骤涉及细胞外糖蛋白-如纤连蛋白，层粘连蛋白和胶原蛋白-与特异性粘附受体的相互作用，其中最具特征的是整合素，一个由α亚基和β亚基组成的异二聚体复合物家族。整合素是高度调节的受体，可以以活性或非活性状态存在。 我们的研究最近集中在肿瘤微环境的线索，可以调节整合素介导的肿瘤细胞迁移和侵袭的可能作用。作为一个模型系统，我们正在研究一种选择素，P-选择素，触发整合素介导的粘附和迁移的培养的人肿瘤细胞的能力。我们专注于这个项目的两个密切相关的方面：P-选择素诱导激活整合素介导的细胞粘附和细胞迁移的机制的特点。 花生四烯酸通过激活α 2-β 1整联蛋白来刺激细胞粘附，该过程依赖于蛋白激酶，包括p38促分裂原活化蛋白激酶。 我们研究了细胞骨架成分与关键信号分子的相互作用，这些分子有助于花生四烯酸处理的MDA-MB-435人乳腺癌细胞的扩散和形态学变化。 花生四烯酸处理的细胞表现出增加的附着和IV型胶原蛋白的蔓延。 脂肪酸处理的细胞显示短皮质肌动蛋白丝与β 1整合素的伪足数量增加，而未处理的细胞显示细长的应力纤维和较少的β 1整合素簇。花生四烯酸处理的细胞伪足和肌动蛋白丝的顶端都富含磷酸化的p38，荧光比率成像显示这种增加是磷酸化的p38特异性的。磷酸-p38从花生四烯酸处理过的细胞提取物中的免疫沉淀物中含有黏着斑蛋白，GST-黏着斑蛋白融合蛋白携带黏着斑蛋白结合磷酸-p38的中心区域，而融合蛋白表达黏着斑蛋白的末端部分没有。 这些数据表明，磷酸化p38与参与肿瘤细胞粘附和扩散的关键粘着斑蛋白上的特定结构域相关联，并且这种关联可以通过肿瘤微环境中的因素来调节。