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: 8350064
• 负责人: William Stetler-Stevenson
• 金额: $ 64.29万
• 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/8350064
• 关键词: 3-Dimensional; A549; Amino Acid Sequence; Amino Acids; Antibodies; Apoptotic; Basement membrane; Behavior; Binding; Biochemical; Biological; Biology; Breast Cancer Cell; Cancer cell line; Cell Differentiation process; Cell Line; Cell Surface Receptors; Cells; Chemicals; Chronic Disease; Complex; Cues; Development; EGF gene; Elements; Endothelial Cells; Epidermal Growth Factor Receptor; Evolution; Excision; Extracellular Matrix; Family; Fibroblast Growth Factor; Fibroblast Growth Factor 2; Fibroblasts; Future; Gene Expression; Genes; Goals; Growth; Growth Factor; Growth Factor Receptors; Homeostasis; Human; Immune response; In Vitro; Inflammation; Inhibition of Matrix Metalloproteinases Pathway; Injection of therapeutic agent; Integrin Binding; Integrin alpha3beta1; Integrins; Kaposi Sarcoma; Laboratories; Lead; Malignant - descriptor; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of lung; Matrix Metalloproteinases; Mediating; Mus; Mutation; N-terminal; Neoplasm Metastasis; Non-Malignant; Normal Cell; Normal tissue morphology; Oncogenes; Organ; Organism; Pathway interactions; Peptides; Phenotype; Phosphorylation; Play; Primary Neoplasm; Process; Protein Tyrosine Phosphatase; Proteins; Reagent; Receptor Activation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Recombinants; Regulation; Relative (related person); Role; Signaling Molecule; Site; Solvents; Stimulation of Cell Proliferation; Structure; Teratocarcinoma; Therapeutic; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinases; Tissues; Tumor Angiogenesis; Tumor Cell Invasion; Tumor Suppression; Tumor Suppressor Genes; Tumor Suppressor Proteins; Vascular Endothelial Growth Factor Receptor-2; Vascular Endothelial Growth Factors; Work; Xenograft Model; angiogenesis; base; blastocyst; cancer therapy; cell behavior; cell growth; cell type; cytokine; epithelial to mesenchymal transition; extracellular; fibrosarcoma; flexibility; human tissue; in vivo; in vivo Model; lung Carcinoma; member; metastatic process; neoplastic cell; new therapeutic target; novel; novel therapeutics; overexpression; precursor cell; pressure; protein aminoacid sequence; receptor; research study; response; synthetic peptide; tumor; tumor growth; tumor progression; tumorigenic

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. Tissue inhibitor of metalloproteinases-2 (TIMP-2) inhibits angiogenesis by several mechanisms involving either MMP inhibition or direct endothelial cell binding. The primary aim of this study was to identify the TIMP-2 region involved in binding to the previously identified receptor integrin alpha3beta1, and to determine whether synthetic peptides derived from this region retained angio-inhibitory and tumor suppressor activity. We demonstrated that the N-terminal domain of TIMP-2 (N-TIMP-2) binds to alpha3beta1 and inhibits vascular endothelial growth factor-stimulated endothelial cell growth in vitro, suggesting that both the alpha3beta1-binding domain and growth suppressor activity of TIMP-2 localize to the N-terminal domain. Using a peptide array approach we identify a 24 amino acid region of TIMP-2 primary sequence, consisting of residues Ile43-Ala66, which shows alpha3beta1-binding activity. Subsequently we demonstrate that synthetic peptides from this region compete for TIMP-2 binding to alpha3beta1 and suppress endothelial growth in vitro. We define a minimal peptide sequence (peptide 8-9) that posses both angio-inhibitory and, using a murine xenograft model of Kaposis sarcoma, anti-tumorigenic activity in vivo. Thus, both the alpha3beta1-binding and angio-inhibitory activities co-localize to a solvent exposed, flexible region in the TIMP-2 primary sequence that is unique in amino acid sequence compared with other members of the TIMP family. Furthermore, comparison of the TIMP-2 and TIMP-1 protein 3-D structures in this region also identified unique structural differences. Our findings demonstrate that the integrin binding, tumor growth suppressor and in vivo angio-inhibitory activities of TIMP-2 are intimately associated within a unique sequence/structural loop (B-C loop).

摘要：EGF 刺激 A549 人肺癌细胞系表明，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 受体磷酸化减少。使用抗整合素抗体的竞争结合实验将整合素 α3β1 鉴定为人微血管内皮细胞 (hMVEC) 上 TIMP-2 的假定细胞表面受体。 Ala+TIMP-2 还抑制 VEGF-A 或 FGF-2 刺激的体外有丝分裂和体内血管生成，从而证明 TIMP-2 的血管抑制活性与 MMP 抑制是分离的。这种效应的机制涉及生长因子受体信号传导的整联蛋白受体失活，称为异源受体失活。这是首次证明整合素可以负向调节受体酪氨酸激酶的激活这项工作通过证明 TIMP 是多功能蛋白质，具有细胞表面受体，并且通过与这些受体相互作用，它们可以直接影响细胞行为，从而定义了 TIMP 生物学的新范式。使用体外和体内模型，我们当前和未来的工作重点是识别 TIMP-2 中的 α3β1 整合素结合域，并进一步了解 TIMP-2 与 α3β1 相互作用后在正常细胞和肿瘤细胞中的细胞效应，以及随后肿瘤微环境的变化。我们的目标是进一步表征 TIMP 在肿瘤微环境中的 MMP 独立和 MMP 依赖性作用及其对肿瘤抑制和/或进展的相对贡献。这些研究应该确定正常组织和肿瘤微环境中细胞外基质调节细胞行为的关键机制，并可能为癌症治疗带来新的治疗策略。这些发现表明，定义负责 TIMP-2 与 alpha3beta1 结合的结构域对于进一步剖析该复杂分子的多种生物活性以及定义该活性对正常和正常微环境的功能贡献至关重要。和恶性组织。该项目的重点是确定 Ala+TIMP-2 的抗血管生成和抗肿瘤生成作用的机制。对人类微血管内皮细胞的初步研究已经证明了一种称为异源受体失活的机制。在这种作用中，TIMP-2 受体 α3β1 通过激活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 (VEGFR)-2、成纤维细胞生长因子受体 (FGFR)-1 和表皮生长因子受体 (EGFR)一种称为 Shp-1 的磷酸酪氨酸磷酸酶。然而，最近在肿瘤细胞和内皮细胞中的实验表明，Ala+TIMP-2 的生长抑制活性更为复杂，似乎涉及细胞凋亡途径和上皮间质转化的基因表达变化，这对于肿瘤侵袭和扩散至关重要。转移。该项目的目的是识别和描述这些途径，旨在将 Ala+TIMP-2 开发为新型癌症治疗剂并确定潜在的新治疗靶点。金属蛋白酶组织抑制剂 2 (TIMP-2) 通过多种机制抑制血管生成，包括抑制 MMP 或直接与内皮细胞结合。本研究的主要目的是鉴定参与与先前鉴定的受体整合素α3β1结合的TIMP-2区域，并确定源自该区域的合成肽是否保留血管抑制和肿瘤抑制活性。我们证明 TIMP-2 (N-TIMP-2) 的 N 末端结构域与 alpha3beta1 结合并在体外抑制血管内皮生长因子刺激的内皮细胞生长，这表明 TIMP 的 alpha3beta1 结合结构域和生长抑制活性-2 定位到 N 端域。使用肽阵列方法，我们鉴定了 TIMP-2 一级序列的 24 个氨基酸区域，由残基 Ile43-Ala66 组成，显示出 alpha3beta1 结合活性。随后我们证明，来自该区域的合成肽竞争 TIMP-2 与 alpha3beta1 的结合，并在体外抑制内皮生长。我们定义了一个最小的肽序列（肽8-9），它具有血管抑制作用，并且使用卡波西肉瘤的鼠异种移植模型，具有体内抗肿瘤活性。因此，α3β1 结合和血管抑制活性共同定位于 TIMP-2 一级序列中暴露于溶剂的柔性区域，与 TIMP 家族的其他成员相比，该区域的氨基酸序列是独特的。此外，该区域中 TIMP-2 和 TIMP-1 蛋白 3-D 结构的比较也发现了独特的结构差异。我们的研究结果表明，TIMP-2 的整合素结合、肿瘤生长抑制剂和体内血管抑制活性在独特的序列/结构环（B-C 环）内密切相关。