The Role of TIMPs in Cell Growth and Differentiation: Tumor Angiogenesis

TIMP 在细胞生长和分化中的作用：肿瘤血管生成

• 批准号: 8158279
• 负责人: William Stetler-Stevenson
• 金额: $ 62.76万
• 依托单位: DIVISION OF CLINICAL 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/8158279
• 关键词: Apoptotic; Binding; Breast Cancer Cell; Cues; Elements; Inhibition of Matrix Metalloproteinases Pathway; Integrin Binding; Malignant Epithelial Cell; Non-Malignant; Receptor Activation; Receptor Signaling; Recombinants; Role; Signaling Molecule; Stimulation of Cell Proliferation; Tissue Inhibitor of Metalloproteinases; Tumor Angiogenesis; Tumor Cell Invasion; Vascular Endothelial Growth Factors; blastocyst; cell growth; human embryonic stem cell; in vivo; in vivo Model

Summary: EGF-stimulation of the A549 human lung carcinoma cell line demonstrated that the suppression of cell growth response was mediated by the activation of protein tyrosine phosphatase activity and resulted in reduced EGF receptor phosphorylation. Competition binding experiments using anti-integrin antibodies identified integrin alpha3beta1 as a putative cell surface receptor for TIMP-2 on human microvascular endothelial cells (hMVECs). Ala+TIMP-2 also inhibited VEGF-A or FGF-2 stimulated mitogenesis in vitro and angiogenesis in vivo a, thus demonstrating that the angio-inhibitory activity of TIMP-2 is dissociable from MMP-inhibition. The mechanism of this effect involves an integrin receptor inactivation of growth factor receptor signaling, known as heterologous receptor inactivation. This was the first demonstration that integrins could negatively regulate activation of a receptor tyrosine kinase This work has defined a new paradigm for TIMP biology by demonstrating that TIMPs are multifunctional proteins, with cell surface receptors and through interaction with these receptors they can directly influence cellular behavior. Using both in vitro and in vivo models our current and future work is focused on identifying the alpha3beta1 integrin binding domain(s) in TIMP-2 and furthering our understanding of the cellular effects following TIMP-2 interaction with alpha3beta1 in both normal and neoplastic cells, as well as the subsequent alterations in the tumor microenvironment. It is our goal to further characterize the MMP-independent and MMP-dependent effects of TIMPs in the tumor microenvironment and their relative contribution to tumor suppression and/or progression. These studies should identify crucial mechanisms in the regulation of cell behavior by the extracellular matrix in normal tissues and the tumor microenvironment, and possibly lead to new therapeutic strategies for cancer treatment. These findings suggest that defining the domain(s) responsible for TIMP-2-binding to alpha3beta1 will be critical to further dissecting the multiple biological activities of this complex molecule, as well as defining the functional contributions of this activity to the microenvironment in both normal and malignant tissues. The focus of this project is to determine the mechanisms of the anti-angiogenic and anti-tumorigenic effects of Ala+TIMP-2. Preliminary work with human microvascular endothelial cells has demonstrated a mechanism known as heterologous receptor inactivation. In this effect the TIMP-2 receptor alpha3beta1 decreases phosphorylation and activation of receptor tyrosine kinases such as the vascular endothelial growth factor receptor (VEGFR)-2, fibroblast growth factor recetpor (FGFR)-1 and epidermal growth factor receptor (EGFR) by activation a phosphotyrosine phosphatase known as Shp-1. However, recent experiments in tumor cells and endothelial cells have revealed that the growth suppressor activity of Ala+TIMP-2 is more complex and appears to involve apoptotic pathways and changes in gene expression of the epithelial to mesenchymal transition that is essential to tumor invasion and metastasis. It is the purpose of this project to identify and delineate these pathways with the aim of developing Ala+TIMP-2 as a novel cancer therapeutic and identifying potential new therapeutic targets.

摘要：A549人肺癌细胞系的EGF刺激表明，细胞生长反应的抑制是通过蛋白酪氨酸磷酸酶活性的激活介导的，并导致EGF受体磷酸化降低。使用抗整合蛋白抗体的竞争结合实验将整联蛋白alpha3beta1鉴定为人类微血管内皮细胞（HMVECS）的TIMP-2的假定细胞表面受体。 ALA+TIMP-2还抑制了VEGF-A或FGF-2在体内刺激的有丝分裂发生和血管生成，因此表明TIMP-2的血管抑制活性与MMP抑制作用可分离。这种作用的机制涉及生长因子受体信号传导的整合素受体失活，称为异源受体失活。这是首次证明整联蛋白可以负调节受体酪氨酸激酶的激活，这项工作通过证明TIMP是多功能蛋白，与细胞表面受体并与这些受体相互作用来定义了TIMP生物学的新范式，它们可以直接影响细胞行为。使用体外和体内模型，我们的当前和将来的工作都集中在TIMP-2中识别alpha3beta1整合蛋白结合域（S），并在正常和肿瘤细胞中与alpha3beta1相互作用后，进一步了解了我们对TIMP-2相互作用后的细胞效应的理解，以及随后的Micro Enronmerm Micro Enronmment中的变化。我们的目标是进一步表征TIMP在肿瘤微环境中及其对肿瘤抑制和/或进展的相对贡献的TIMP的依赖性和MMP依赖性作用。这些研究应确定正常组织中细胞外基质和肿瘤微环境调节细胞行为的关键机制，并可能导致新的治疗策略用于癌症治疗。这些发现表明，定义负责TIMP-2结合到alpha3beta1的结构域对于进一步剖析该复合物分子的多种生物学活性至关重要，并定义了这种活性对正常组织和恶性组织中微环境的功能贡献。该项目的重点是确定ALA+TIMP-2的抗血管生成和抗肿瘤效应的机制。与人类微血管内皮细胞的初步工作表明了一种称为异源受体失活的机制。在这种效果中，TIMP-2受体α3Beta1降低受体酪氨酸激酶的磷酸化和激活，例如血管内皮生长因子受体受体（VEGFR）-2，成纤维细胞生长因子recetpor（FGFR）-1和表皮生长因子受体受体（EGFR）通过激活磷酸酶磷酸酶磷酸酶磷酸酶（1）。然而，最近在肿瘤细胞和内皮细胞中进行的实验表明，ALA+TIMP-2的生长抑制活性更为复杂，似乎涉及凋亡途径以及上皮细胞对间质转变的基因表达的变化，这对于肿瘤侵袭和转移至关重要。该项目的目的是识别和描述这些途径，目的是将ALA+TIMP-2开发为一种新型的癌症治疗，并确定潜在的新治疗靶标。