Endolysosomal-nuclear communication mediated through V-ATPase and NHE9 dependent epigenetic signaling

通过 V-ATP 酶和 NHE9 依赖的表观遗传信号介导的内溶酶体-核通讯

• 批准号: 9759328
• 负责人: Ronald Laribee
• 金额: $ 16.53万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759328
• 关键词: Acetylation; Affect; Alkylating Agents; Animals; Antineoplastic Agents; Attenuated; Binding; Biochemical; Cancer Biology; Cell model; Cells; Chromatin; Communication; Complex; Coupled; Critical Pathways; Cyclic AMP-Dependent Protein Kinases; Cytoplasmic Organelle; DNA; DNA Damage; DNA Repair; Data; Deacetylase; Defect; Drug Targeting; Environment; Enzymes; Epigenetic Process; Exposure to; FRAP1 gene; Family; Foundations; Gene Expression; Genes; Genetic Screening; Genetic Transcription; Genotoxic Stress; Glioblastoma; Growth; Growth Factor; Histone Acetylation; Histone H3; Histone H4; Homologous Gene; Human; Impairment; Knock-out; Libraries; Malignant Neoplasms; Malignant neoplasm of brain; Mammals; Mediating; Metabolic; Metabolic stress; Metabolism; Modeling; Modification; Neoplasm Metastasis; Nuclear; Nucleosomes; Nutrient; Orthologous Gene; Pathway interactions; Patients; Phenotype; Phosphorylation; Process; Proton Pump; Protons; Regulation; Repression; Resistance; Role; Saccharomycetales; Signal Pathway; Signal Transduction; Sirtuins; Stress; System; Testing; Yeasts; aerobic glycolysis; cancer cell; chemotherapeutic agent; chemotherapy; chromatin remodeling; drug development; epigenetic regulation; epigenome; extracellular; inhibitor/antagonist; innovation; mutant; neoplastic cell; novel; overexpression; response; standard of care; temozolomide; therapeutic candidate; therapeutic target; tool; tumor; tumorigenesis; vacuolar H+-ATPase; yeast genetics

Tumors are exposed to constantly changing nutrient environments which creates metabolic stress that impairs their growth and proliferation. Consequently, cancer cells evolve phenotypic adaptations to contend with this nutrient flux that require epigenetic and transcriptional reprogramming. These phenotypic adaptations also can affect tumor cell sensitivity to chemotherapeutic agents. How cytoplasmic organelles involved in nutrient signaling exert their effects on the nuclear epigenome remains a fundamental problem to define since these pathways are candidate therapeutic targets for anticancer drug development. The V-ATPase is an evolutionarily conserved multimeric proton pump that acidifies the endolysosomal compartment to regulate intracellular pH and activate essential nutrient signaling pathways. Na+/H+ exchanger (NHE) factors, specifically NHE9, antagonize V-ATPase dependent endosomal acidification. NHE9 is overexpressed in many tumors, and recent studies have demonstrated that NHE9 overexpression in glioblastoma (GBM) contributes directly to tumorigenesis. Intriguingly, genetic screens in budding yeast identified both the V-ATPase and the yeast NHE9 ortholog, Nhx1, as regulators of histone H3 and H4 (H3/H4) acetylation through unknown mechanisms. Our preliminary data demonstrate that V-ATPase signaling in human GBM cells also regulates H3/H4 acetylation, thus demonstrating that the V-ATPase is an evolutionarily conserved epigenetic regulator. This project will test the innovative hypothesis that the V-ATPase and Nhx1/NHE9 regulate the endolysosomal- nuclear communication required for epigenetic adaptation to altered nutrient states. Using yeast and human GBM models, we will perform the following Specific Aims. In Aim I, we will identify the key nutrient signaling pathways downstream of the V-ATPase controlling global H3/H4 acetylation, and then we will determine if this involves repression of the sirtuin family of deacetylases or if it involves non-sirtuin mechanisms. We will test specifically if V-ATPase dependent H3/H4 acetylation regulates the binding of ATP-dependent chromatin remodeling enzymes important for transcription of metabolic genes. In Aim II, we will determine if V-ATPase dependent H3/H4 acetylation controls the DNA damage response to alkylating agents, including the GBM standard of care chemotherapeutic agent temozolomide (TMZ), by anchoring ATP-dependent nucleosome remodeling enzymes onto chromatin. Upon the project's completion, we will have defined a novel paradigm by which the endolysosomal compartment regulates nuclear epigenetic pathways critical for metabolic gene expression and sensitivity to genotoxic stress.

肿瘤暴露于不断变化的养分环境，从而产生代谢压力会损害 它们的生长和扩散。因此，癌细胞进化了表型适应以与此抗衡 需要表观遗传和转录重编程的营养通量。这些表型适应也可以 影响肿瘤细胞对化学治疗剂的敏感性。细胞质细胞器如何参与营养 信号传导对核表观基因组的影响仍然是一个基本问题，因为这些问题 途径是抗癌药物开发的候选治疗靶标。 V-ATPase是 进化保守的多聚体质子泵，将内溶液室酸化以调节 细胞内pH并激活必需的养分信号通路。 Na+/H+交换器（NHE）因素， 特别是NHE9，拮抗依赖V-ATPase的内体酸化。 NHE9在许多人中过表达 肿瘤，最近的研究表明，胶质母细胞瘤（GBM）中的NHE9过表达有助于 直接进行肿瘤发生。有趣的是，萌芽酵母中的遗传筛选都确定了V-ATPase和 酵母NHE9直系同源物NHX1作为组蛋白H3和H4（H3/H4）乙酰化的调节剂 机制。我们的初步数据表明，人类GBM细胞中的V-ATPase信号传导也可以调节 H3/H4乙酰化，因此表明V-ATPase是进化保守的表观遗传调节剂。 该项目将测试V-ATPase和NHX1/NHE9调节内溶性 - 表观遗传学适应改变营养状态所需的核通信。使用酵母和人 GBM模型，我们将执行以下特定目标。在AIM I中，我们将确定关键的营养信号传导 控制全局H3/H4乙酰化的V-ATPase下游的途径，然后我们将确定是否 涉及抑制脱乙酰基酶家族，或者是否涉及非服装机制。我们将测试 具体而言，如果V-ATPase依赖性H3/H4乙酰化调节ATP依赖性染色质的结合 重塑酶对代谢基因转录很重要。在AIM II中，我们将确定V-ATPase是否 依赖性H3/H4乙酰化控制对烷基化剂的DNA损伤反应，包括GBM 护理标准化学治疗剂替莫唑胺（TMZ），通过锚定ATP依赖性核小体 重塑酶在染色质上。项目完成后，我们将定义一个新颖的范式 内溶性室调节代谢基因至关重要的核表观遗传途径 对遗传毒性应激的表达和敏感性。