Defining a mechanism of LRP1B tumor suppression in glioblastoma

确定胶质母细胞瘤中 LRP1B 肿瘤抑制的机制

• 批准号: 9258045
• 负责人: William Ellis Fondrie
• 金额: $ 3.02万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9258045
• 关键词: Affect; Affinity Chromatography; Alzheimer' s Disease; Amino Acid Sequence; Anchorage-Independent Growth; Atherosclerosis; Attenuated; Binding; Cell Nucleus; Cell Proliferation; Cells; Clinical; Combined Modality Therapy; Complement; Complex; DNA; DNA Sequence; Data; Development; Disease; Drug Design; Epidermal Growth Factor Receptor; Excision; Extracellular Domain; Family; Future; Gene Expression; Gene Targeting; Genes; Glioblastoma; Histopathology; Human; Investigation; Knowledge; LDL-Receptor Related Protein 1; Laboratories; Lipoprotein Receptor; Low Density Lipoprotein Receptor; MGMT gene; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of brain; Mass Spectrum Analysis; Mediating; Molecular; Molecular Biology Techniques; Mutation; Nature; Nuclear; Operative Surgical Procedures; Outcome; Patients; Pattern; Phosphorylation; Prevalence; Process; Progression-Free Survivals; Property; Proteins; Proteolysis; Proteomics; Publishing; Renal Cell Carcinoma; Research; Role; Signal Pathway; Signal Transduction; Smooth Muscle Myocytes; Survival Rate; Systems Biology; Tertiary Protein Structure; Testing; The Cancer Genome Atlas; Therapeutic; Treatment Efficacy; Tumor Cell Invasion; Tumor Suppression; Tumor Suppressor Proteins; U118; WNT Signaling Pathway; base; beta catenin; cancer type; cell motility; chemotherapy; chromatin immunoprecipitation; improved; insight; mRNA Expression; migration; mutant; next generation sequencing; protein complex; receptor; response; sequential proteolysis; temozolomide; transcription factor; tumor; tumor growth; tumor progression

PROJECT SUMMARY Glioblastoma is the most common form of malignant brain tumor, with a dismal 5-year survival rate of 5.0% after multimodal therapy. The highly aggressive and infiltrative properties of glioblastoma cells complicate treatment by evading surgical resection and local chemotherapies. Consequently, investigation into mechanisms of glioblastoma proliferation, migration and invasion are needed to develop improved therapeutics and increase the efficacy of current treatments. The low-density lipoprotein receptor-related protein 1B (LRP1B) is a large endocytic receptor that has been identified as one of the most commonly deleted genes across human cancers. Recently, deletion of LRP1B was shown to be significantly associated with poor overall survival and poor progression-free survival in glioblastoma patients. Despite its prevalence across human cancers, the mechanism(s) by which LRP1B acts as a tumor suppressor are largely unknown. A published study from our lab demonstrated that LRP1B undergoes regulated intramembrane proteolysis, a process that involves the sequential proteolysis of a protein to release a soluble extracellular domain and intracellular domain. The LRP1B intracellular domain (LICD) was found to localize to the nucleus and inhibit anchorage- independent growth. Additionally, LRP1B has been found to interact with proteins involved in Wnt signaling and a number of transcription factors. Preliminary studies have found strong negative correlations of LRP1B mRNA expression with the expression of Wnt signaling activators and target genes in glioblastoma patients. With this support, the central hypothesis of this project is that the deletion of LRP1B promotes glioblastoma progression through increased Wnt signaling. Our hypothesis will be tested in the following specific aims. 1) Determine if the LRP1B intracellular domain is sufficient to attenuate glioblastoma proliferation and migration. 2) Define the mechanism(s) by which LRP1B attenuates cellular proliferation and migration. Specific Aim 1 will investigate the LRP1B intracellular domain and define the specific amino acid sequences that contribute to its tumor suppressor function. To complement these studies, Specific Aim 2 will investigate the protein and DNA interactions of the LRP1B intracellular domain, and will quantify global proteomic and phosphorylation changes that occur upon LRP1B expression. Together these studies will give insight into mechanisms by which LRP1B mediates tumor suppression. These aims will be accomplished using a variety of strategies, including mass spectrometry-based proteomics, chromatin immunoprecipitation, next-generation sequencing and molecular biology techniques. Mechanistic knowledge of LRP1B has the potential to enable better therapeutic choices and reveal specific targets for rational drug design. Additionally, these insights reach beyond glioblastoma treatment, given the prevalence of LRP1B deletions across human cancers and the role of LRP1B in atherosclerosis and Alzheimer’s disease.

项目摘要 胶质母细胞瘤是最常见的恶性脑肿瘤，其5年生存率只有5.0% 多模式治疗后。胶质母细胞瘤细胞的高度侵袭性和浸润性使其复杂化， 避免手术切除和局部化疗。因此，调查 需要胶质母细胞瘤增殖、迁移和侵袭的机制来开发改进的治疗方法 并提高目前治疗的效果。低密度脂蛋白受体相关蛋白1B LRP1B是一种大的内吞受体，已被鉴定为最常见的缺失基因之一 在人类癌症中。最近，LRP1B的缺失被证明与总体不良相关。 在胶质母细胞瘤患者中的生存率和无进展生存率差。尽管它在人类中普遍存在， 在癌症中，LRP1B作为肿瘤抑制因子的机制在很大程度上是未知的。已发布的 我们实验室的研究表明，LRP 1B经历了受调节的膜内蛋白水解，这一过程 涉及蛋白质的顺序蛋白水解以释放可溶性细胞外结构域和细胞内结构域， 域LRP 1B胞内结构域（LICD）被发现定位于细胞核并抑制锚定。 独立成长。此外，已发现LRP 1B与参与Wnt信号传导的蛋白质相互作用 和一些转录因子。初步研究发现，LRP 1B与 胶质母细胞瘤患者中Wnt信号激活剂和靶基因的mRNA表达。 有了这个支持，这个项目的中心假设是LRP1B的缺失促进胶质母细胞瘤 通过增加Wnt信号传导进展。我们的假设将在以下具体目标中得到检验。第一章 确定LRP1B细胞内结构域是否足以减弱胶质母细胞瘤增殖和迁移。 2)定义LRP1B减弱细胞增殖和迁移的机制。具体目标1将 研究LRP1B胞内结构域，并确定有助于其表达的特定氨基酸序列。 肿瘤抑制功能为了补充这些研究，Specific Aim 2将研究蛋白质和DNA LRP1B胞内结构域的相互作用，并将量化整体蛋白质组学和磷酸化变化 LRP1B的表达。总之，这些研究将深入了解LRP 1B的机制， 介导肿瘤抑制。这些目标将通过各种战略来实现，包括大规模 基于光谱的蛋白质组学、染色质免疫沉淀、下一代测序和分子生物学 生物技术LRP1B的机制知识有可能实现更好的治疗选择 并揭示合理药物设计的具体目标。此外，这些见解超越了胶质母细胞瘤， 考虑到LRP1B缺失在人类癌症中的流行率以及LRP1B在癌症治疗中的作用， 动脉粥样硬化和阿尔茨海默病。