Cadherin-catenin Mediated Contact Inhibition of Cell Growth

钙粘蛋白-连环蛋白介导的细胞生长接触抑制

• 批准号: 8505505
• 负责人: BARRY M. GUMBINER
• 金额: $ 50.53万
• 依托单位: UNIVERSITY OF VIRGINIA
• 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 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8505505
• 关键词: Adhesions; Adhesives; Affect; Binding; Boxing; Cadherins; Cell Culture Techniques; Cell surface; Cell-Cell Adhesion; Cells; Communication; Complex; Contact Inhibition; Cytoplasmic Tail; Development; Drosophila genus; E-Cadherin; Embryo; Embryonic Development; Epidermal Growth Factor Receptor; Equilibrium; Growth; Growth Factor; Growth Factor Receptors; Homologous Gene; Malignant Neoplasms; Mammalian Cell; Mammals; Mammary Neoplasms; Mediating; Mediator of activation protein; Membrane; Modeling; Molecular; Morphogenesis; Mus; Natural regeneration; Normal tissue morphology; Nuclear; Organ Size; Pathway interactions; Phosphorylation; Physiological; Play; Process; Property; Proteins; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Reporting; Role; Signal Pathway; Signal Transduction; Testing; Tissues; Transcription Coactivator; Work; Wound Healing; beta catenin; cell growth; cell type; in vivo; mammary gland development; neoplastic cell; novel; src-Family Kinases; tissue regeneration; tumor; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): Contact inhibition limits cell growth in tissues, but is highly subject to regulation. It can be overcome in rapidly growing tissues during development, regeneration, and wound healing. Contact inhibition is frequently lost in tumor cells, allowing tumors to grow well beyond their normal tissue constraints. The mechanisms underlying contact inhibition are poorly understood, but cadherin-mediated cell-cell adhesion is thought to play an important role. We have shown that homophilic adhesive binding between E-cadherin proteins at the cell surface, in association with catenins bound to their cytoplasmic domains, directly mediate contact inhibition of growth. We've found that cadherin-catenin mediated contact inhibition occurs via two major pathways; inhibition of growth factor receptor signaling, which we now find results from inhibition of Src family kinases (SFKs); and our preliminary findings also implicate the Hippo signaling pathway, in particular the nuclear localization of the Hippo pathway transcriptional mediator YAP. The Hippo pathway was originally discovered as a regulator of organ size in Drosophila embryos, and recently has been shown to regulate mammalian cell growth, contact inhibition, and tumor development. We have made another novel preliminary finding that growth factor signaling and SFK activity affect YAP nuclear localization and function in some cells, suggesting another important mechanism of Hippo pathway regulation. The overall hypothesis is that E-cadherin-catenin regulates contact inhibition of growth both by stimulating the Hippo signaling pathway and by inhibiting src family kinase (SFK) activity, and in this way it serves to coordinate or balance growth inhibitory signaling with the mitogenic signaling by growth factor receptors. We will first investigate the functional and physiological relationships between E-cadherin-2-catenin mediate adhesion, Hippo pathway signaling, SFK signaling, and Epidermal Growth Factor Receptor (EGFR) signaling. We will determine the molecular mechanisms by which these pathways regulate each other in cell culture models and then test their importance in vivo for tumor formation and normal tissue development in mice. The specific aims are: A. Elucidate the mechanism(s) by which homophilic binding between E-cadherin-catenin complexes regulates signaling through the Hippo pathway. B. Determine how EGFR and SFK signaling regulate the nuclear localization and function of the Hippo pathway transcriptional activator YAP, understand the role of Hippo pathway-mediated growth inhibition in the regulation of mitogenic signaling by EGFR and SFKs, and elucidate the mechanism(s) of regulation SFK activity by E-cadherin-catenin adhesive complexes. C. Evaluate the roles of E-cadherin-catenin-mediated contact inhibition and Hippo pathway signaling in the development of mammary glands and mammary tumors in vivo in mice, and their roles in tumorigenesis driven by Receptor Tyrosine Kinase (RTK) and SFK signaling pathways. Findings from these studies should reveal how contact inhibition regulates normal tissue development and how the loss of contact inhibition leads to the formation and progression of tumors.

描述（由申请人提供）：接触抑制限制组织中的细胞生长，但高度受到调节。在发育、再生和伤口愈合过程中，快速生长的组织可以克服它。肿瘤细胞中经常失去接触抑制，使肿瘤生长远远超出其正常组织的限制。人们对接触抑制的机制知之甚少，但钙粘蛋白介导的细胞间粘附被认为发挥着重要作用。我们已经证明，细胞表面的 E-钙粘蛋白之间的同亲粘附结合与与其细胞质结构域结合的连环蛋白相关，直接介导生长的接触抑制。我们发现钙粘蛋白-连环蛋白介导的接触抑制通过两条主要途径发生；抑制生长因子受体信号传导，我们现在发现这是由于抑制 Src 家族激酶 (SFK) 造成的；我们的初步研究结果还涉及 Hippo 信号通路，特别是 Hippo 通路转录介质 YAP 的核定位。 Hippo 通路最初被发现是果蝇胚胎器官大小的调节因子，最近被证明可以调节哺乳动物细胞生长、接触抑制和肿瘤发展。我们取得了另一项新颖的初步发现，即生长因子信号传导和 SFK 活性影响某些细胞中 YAP 的核定位和功能，这表明 Hippo 通路调节的另一个重要机制。总体假设是，E-钙粘蛋白-连环蛋白通过刺激 Hippo 信号通路和抑制 src 家族激酶 (SFK) 活性来调节生长的接触抑制，并以这种方式协调或平衡生长抑制信号与有丝分裂信号通过生长因子受体。我们将首先研究 E-cadherin-2-catenin 介导的粘附、Hippo 通路信号、SFK 信号和表皮生长因子受体 (EGFR) 信号之间的功能和生理关系。我们将确定这些途径在细胞培养模型中相互调节的分子机制，然后测试它们在体内对小鼠肿瘤形成和正常组织发育的重要性。具体目标是： A. 阐明 E-钙粘蛋白-连环蛋白复合物之间的同亲结合通过 Hippo 途径调节信号传导的机制。 B. 确定 EGFR 和 SFK 信号如何调节 Hippo 通路转录激活因子 YAP 的核定位和功能，了解 Hippo 通路介导的生长抑制在 EGFR 和 SFK 促有丝分裂信号调节中的作用，并阐明其机制E-钙粘蛋白-连环蛋白粘附复合物调节 SFK 活性的研究。 C. 评估 E-钙粘蛋白-连环蛋白介导的接触抑制和 Hippo 通路信号在小鼠体内乳腺和乳腺肿瘤发育中的作用，以及它们在受体酪氨酸激酶 (RTK) 和 SFK 信号通路驱动的肿瘤发生中的作用。这些研究的结果应该揭示接触抑制如何调节正常组织发育以及接触抑制的丧失如何导致肿瘤的形成和进展。