Negative regulation by proteasomal degradation of receptor tyrosine kinase ErbB3

受体酪氨酸激酶 ErbB3 的蛋白酶体降解负调节

• 批准号: 8452424
• 负责人: Ignat Printsev
• 金额: $ 3.54万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8452424
• 关键词: 26S proteasome; Automobile Driving; Biochemical; Biochemistry; Breast; Breast Cancer Treatment; Cell surface; Cells; Co-Immunoprecipitations; Cytosol; Data; Degradation Pathway; Development; ERBB2 gene; Endoplasmic Reticulum; Ensure; Enzymes; Epidermal Growth Factor Receptor; Epithelial Cells; Event; Excision; Family; Fingers; Foundations; Goals; Growth; Human; Immunoprecipitation; Knowledge; Lesion; Light; Lysosomes; Malignant Neoplasms; Mammary Neoplasms; Mammary gland; Mediating; Membrane; Methods; Microscopy; Mission; Molecular; Molecular Biology; Molecular Cloning; Mutagenesis; Nature; Pathway interactions; Patients; Play; Polyubiquitin; Process; Property; Proteins; Quality Control; Reaction; Receptor Protein-Tyrosine Kinases; Regulation; Research; Resistance; Resolution; Roche brand of trastuzumab; Role; Series; Signal Transduction; Site; Solid Neoplasm; System; Techniques; Therapeutic; Therapeutic Intervention; Trastuzumab; Tumor Suppression; Ubiquitin-Conjugating Enzymes; Ubiquitination; Western Blotting; Work; anticancer research; arm; burden of illness; cancer therapy; cancer type; cell growth; design; drug development; humanized monoclonal antibodies; insight; malignant breast neoplasm; malignant state; molecular assembly/self assembly; multicatalytic endopeptidase complex; neoplastic cell; novel; overexpression; protein folding; protein misfolding; receptor; response; standard of care; stem; tissue culture; tumor; tumor initiation; tumor progression; tumorigenesis; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The primary objective of this project is to describe the regulatory systems of cellular growth in order to provide a foundation for cancer therapeutics and drug development. This goal well reflects the mission of the NCI as the resolution of this project would provide fundamental knowledge of a cellular system as a means to gain insight to the development of novel treatments for cancer and thereby reducing the burdens of disease on the state. The focus of this project will be on growth factor receptor tyrosine kinases (RTK) whose dysregulation contributes to solid tumor initiation, growth, and progression in an immense number and variety of cancer types (1-3). Treatments for these cancers are often designed to stem or retard the functionality of RTKs as in the case of ErbB2, an RTK overexpressed in 25% of breast cancers, where receptor activity is curtailed with trastuzumab (Herceptin), a humanized monoclonal antibody specific to ErbB2 (4). However, in recent years it has emerged that the overexpression of ErbB3, an RTK of the same family, contributes to the growth and progression of ErbB2-positive breast tumors, as well as to therapeutic resistance, a major barrier in breast cancer treatment (5), thus leading to a need of describing the regulatory mechanisms that restrict ErbB3 levels in normal (non-transformed) mammary epithelial cells. Studies in our lab strongly suggest that normal (non-transformed) mammary epithelial cells employ potent post-transcriptional negative regulatory mechanisms that restrict ErbB3 levels, while tumor cells inactivate these mechanisms to promote their growth and malignancy (6,7). Post-transcriptional negative regulation of RTKs often occurs through the lysosome-mediated degradation of receptors that have been internalized from the cell surface (8,9). However, our lab has recently discovered that cells suppress ErbB3 levels via the degradation of newly synthesized receptors at the endoplasmic reticulum (ER); extraneous receptors are targeted to the proteasome via their ubiquitination (10). This project will explore this novel type of regulatin of ErbB3 at the endoplasmic reticulum. Mechanisms of this control mechanism will be elucidated including the protein components that are involved in the targeting, ubiquitination, and retrotranslocation of ErbB3 to the cytosol for 26S proteasome-dependent degradation. This project is intended to be carried out using techniques in biochemistry, cell, and molecular biology including mammalian tissue culture, immunoprecipitation, western blotting, microscopy, and molecular cloning. The project will be supplemented by regular attendance of scientific presentations on topics in cancer research, biochemistry, and molecular biology that would be at all relevant to the subject matter and approaches outlined above. Furthermore, courses related to the project would aid in the development of perspectives and strategies important to the progression of the technical and theoretical facets of the research.

描述（由申请人提供）：该项目的主要目标是描述细胞生长的调节系统，以便为癌症治疗和药物开发提供基础。这一目标很好地体现了 NCI 的使命，因为该项目的解决方案将提供细胞系统的基础知识，作为深入了解癌症新疗法开发的手段，从而减轻国家的疾病负担。该项目的重点是生长因子受体酪氨酸激酶 (RTK)，其失调会导致多种癌症类型中实体瘤的发生、生长和进展 (1-3)。这些癌症的治疗通常旨在阻止或延缓 RTK 的功能，例如 ErbB2（一种在 25% 的乳腺癌中过度表达的 RTK），其中受体活性会被曲妥珠单抗（赫赛汀）（一种针对 ErbB2 的人源化单克隆抗体）抑制 (4)。然而，近年来发现 ErbB3（同一家族的 RTK）的过度表达会促进 ErbB2 阳性乳腺肿瘤的生长和进展，以及治疗耐药性，这是乳腺癌治疗的主要障碍 (5)，因此需要描述限制正常（非转化）乳腺上皮细胞中 ErbB3 水平的调节机制。我们实验室的研究强烈表明，正常（未转化）乳腺上皮细胞采用有效的转录后负调节机制来限制 ErbB3 水平，而肿瘤细胞则使这些机制失活以促进其生长和恶性 (6,7)。 RTK 的转录后负调节通常通过溶酶体介导的从细胞表面内化的受体降解来发生 (8,9)。然而，我们的实验室最近发现细胞通过降解内质网 (ER) 新合成的受体来抑制 ErbB3 水平；外来受体通过泛素化作用靶向蛋白酶体 (10)。该项目将探索 ErbB3 在内质网中的这种新型调节方式。该控制机制的机制将被阐明，包括参与 ErbB3 的靶向、泛素化和逆转位至胞质溶胶以进行 26S 蛋白酶体依赖性降解的蛋白质成分。该项目旨在利用生物化学、细胞和分子生物学技术进行，包括哺乳动物组织培养、免疫沉淀、蛋白质印迹、显微镜和分子克隆。该项目将通过定期参加有关癌症研究、生物化学和分子生物学主题的科学演讲来补充，这些主题与上述主题和方法完全相关。此外，与该项目相关的课程将有助于发展对研究的技术和理论方面的进展很重要的观点和策略。