Force Sensing with Nanotubes

用纳米管进行力传感

• 批准号: 8191774
• 负责人: Brenda Frances Farrell
• 金额: $ 20.42万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8191774
• 关键词: Actins; Adhesives; Advanced Development; Binding; Biopolymers; Breast Carcinoma; Carcinoma; Cell membrane; Cells; Characteristics; Chemicals; Data; Diagnostic Neoplasm Staging; Embryonic Development; Epidermal Growth Factor; Epidermal Growth Factor Receptor; Epithelial; Epithelial Cells; F-Actin; Filament; Filopodia; Fluorescence; Fluorescence Microscopy; Free Energy; Goals; Growth Factor; Growth and Development function; Human; Image; Immune response; Invaded; Length; Life; Malignant Neoplasms; Mammalian Cell; Measurable; Measurement; Measures; Mechanics; Mediating; Membrane; Methodology; Methods; Microscopy; Modeling; Molecular; Monitor; Motor; Movement; Nanotechnology; Nanotubes; Natural regeneration; Neoplasm Metastasis; Organism; Pathway interactions; Play; Preparation; Primary Neoplasm; Production; Proteins; Reaction; Relative (related person); Research Technics; Role; Site; Solutions; Staging; Structure; Temperature; Time; Tissues; Tongue; Traction; Tube; Work; Wound Healing; base; cancer cell; cell growth; cell motility; cell transformation; chemical reaction; depolymerization; design; insight; laser tweezer; migration; monomer; mouth squamous cell carcinoma; neoplastic cell; operation; optical traps; polymerization; receptor; rho GTP-Binding Proteins; sensor

DESCRIPTION (provided by applicant): Most human malignancies are of epithelial origin. Transformed epithelial cells spread from the primary tumor site and invade surrounding tissues through the production of migratory structures (e.g., filopodia, invadopodia, and lamellapodia). The relative abundance of migratory structures is correlated with the metastatic potential of tumor cells. Migratory structures form by remodeling actin at the leading edge of transformed epithelial cells. Growth factors (e.g., epidermal growth factor, EGF) initiate actin remodeling by targeting their receptors (e.g., epidermal growth factor receptor) on the plasma membrane of transformed cells. Although the EGF pathway is well characterized, we lack experimental evidence to quantify forces that contribute to migration, including adhesive traction, resistive viscous drag, and protrusive forces. This work will focus on protrusive forces that occur at the leading edge of a living cell. They arise when the chemical energy released upon actin polymerization produces a pushing force against the plasma membrane, driven by the greater concentration of monomeric actin in the solution relative to the biopolymer. When an actin bundle is attached to the plasma membrane, depolymerization of F-actin produces a pulling force on the membrane. This reverse chemical reaction is driven by a lower concentration of monomer in the bulk relative to the biopolymer. Experimental measurements of the magnitude and time course of the pushing force in living cells are lacking and there are no measurements of the pulling force arising from the depolymerization of F-actin. The goal of this work is to determine the time course and magnitude of the pushing and pulling forces at the fast-growing end of an F-actin bundle. We will use the membrane as a sensor to determine the force at the motor-level in cancer cells. We will stimulate transformed epithelial cells to form migratory structures by EGF or with active effectors within the EGF pathway. We will use optical tweezers to measure the force, fluorescence microscopy to image F- actin, and develop methodology to measure both simultaneously. This work will provide a functional model of the actin motor at a leading edge of transformed epithelial cells, and advance the field in understanding cell migration during the invasive stage of cancer by providing measurements of the protrusive force at one leading edge. It will provide a quantitative experimental method to investigate the transduction machinery of this chemical motor, and fundamental insight into the integrated operations of the cell membrane and actin motor. This work will provide a basis to design force sensors for applications in nanotechnology. PUBLIC HEALTH RELEVANCE: This study will help us to better understand specific roles of F-actin, a key protein in all mammalian cells. This protein plays an important role in cell growth and development. It has a significant role during the invasive stage of many aggressive cancers. The research techniques will advance the development of bio-molecular sensors for applications in nanotechnology.

描述（由申请人提供）：大多数人类恶性肿瘤都是上皮起源的。转化的上皮细胞从原发肿瘤部位扩散并通过产生迁移结构（例如丝状伪足、侵入伪足和板状伪足）侵入周围组织。迁移结构的相对丰度与肿瘤细胞的转移潜力相关。迁移结构是通过在转化的上皮细胞前缘重塑肌动蛋白而形成的。生长因子（例如表皮生长因子，EGF）通过靶向转化细胞质膜上的受体（例如表皮生长因子受体）来启动肌动蛋白重塑。尽管 EGF 途径已得到很好的表征，但我们缺乏实验证据来量化有助于迁移的力，包括粘附牵引、阻力粘性阻力和突出力。这项工作将重点关注活细胞前缘发生的突出力。当肌动蛋白聚合时释放的化学能产生对质膜的推力时，它们就会出现，这是由溶液中相对于生物聚合物浓度更高的单体肌动蛋白驱动的。当肌动蛋白束附着在质膜上时，F-肌动蛋白的解聚会对膜产生拉力。这种逆化学反应是由本体中相对于生物聚合物较低浓度的单体驱动的。缺乏对活细胞中推力大小和时间过程的实验测量，也没有对 F-肌动蛋白解聚产生的拉力进行测量。这项工作的目标是确定 F-肌动蛋白束快速生长端推力和拉力的时间过程和大小。我们将使用膜作为传感器来确定癌细胞运动水平的力。我们将通过 EGF 或 EGF 通路内的活性效应器刺激转化的上皮细胞形成迁移结构。我们将使用光镊测量力，使用荧光显微镜对 F-肌动蛋白成像，并开发同时测量两者的方法。这项工作将提供转化上皮细胞前缘肌动蛋白运动的功能模型，并通过提供一个前缘突出力的测量来推进理解癌症侵袭阶段细胞迁移的领域。它将提供一种定量实验方法来研究这种化学马达的转导机制，并为细胞膜和肌动蛋白马达的集成操作提供基本见解。这项工作将为设计纳米技术应用的力传感器提供基础。 公共健康相关性：这项研究将帮助我们更好地了解 F-肌动蛋白（所有哺乳动物细胞中的一种关键蛋白）的具体作用。这种蛋白质在细胞生长和发育中起着重要作用。它在许多侵袭性癌症的侵袭阶段发挥着重要作用。该研究技术将推动纳米技术应用生物分子传感器的开发。