Linking cancer cell metabolic reprogramming to the DNA repair mechanism

将癌细胞代谢重编程与 DNA 修复机制联系起来

• 批准号: 8879428
• 负责人: Roger A Greenberg
• 金额: $ 17.4万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8879428
• 关键词: ATP Citrate (pro-S)-Lyase; Acetyl Coenzyme A; Acetylation; Adverse effects; Affect; Anabolism; BRCA1 gene; Biological Assay; Cancer Etiology; Carbon; Cell Cycle; Cell Survival; Cells; Chromosome abnormality; DNA Damage; DNA Double Strand Break; DNA Modification Process; DNA Repair; DNA Repair Pathway; DNA repair protein; Data; Development; Double Strand Break Repair; Enzymes; Epigenetic Process; Equilibrium; Fatty Acids; G2 Phase; Genome Stability; Genomic Instability; Glucose; Growth; Histone Acetylation; Histone H4; Ionizing radiation; Joints; Link; Lipids; Lysine; Mediating; Metabolic; Metabolic Control; Metabolism; Mutation; Nonhomologous DNA End Joining; Nuclear; Oncogenes; Oncogenic; PARP inhibition; Pathway interactions; Play; Predisposition; Process; Production; Proteins; Regulation; Role; S Phase; STK11 gene; Signal Transduction; Site; Source; Testing; Therapeutic; cancer cell; chemotherapeutic agent; chemotherapy; chromatin immunoprecipitation; chromatin modification; cytotoxic; genome integrity; glucose uptake; histone modification; homologous recombination; improved; inhibitor/antagonist; novel; novel strategies; p53-binding protein 1; public health relevance; repaired; response

 DESCRIPTION (provided by applicant): Metabolism is extensively rewired in cancer cells to support biosynthesis, growth, and proliferation. It has recently become apparent that many histone and DNA modifications are sensitive to cellular metabolic state. Histone acetylation is a dynamic chromatin modification, and global levels of histone acetylation are responsive to availability of the metabolite acetyl-CoA. However, the functional significance of metabolic control of histone acetylation remains poorly understood. The Wellen lab has recently shown that oncogenic activation of the PI3K-Akt pathway in cancer cells promotes acetyl-CoA production and elevated histone acetylation levels, indicating that normal metabolic controls on histone acetylation are disrupted in cancer cells. Extensive chromatin modifications, including histone acetylation, play crucial roles in the regulation of DNA repair. The Greenberg lab has recently shown that acetylation of histone H4 lysine 16 (H4K16ac) at sites of DNA double strand breaks (DSBs) plays a key role in recruitment of DNA repair proteins such as BRCA1 and utilization of DNA repair mechanisms. DSBs are repaired either by homologous recombination (HR) or non-homologous end joining (NHEJ). HR deficiencies, such as occur with BRCA1/2 mutations, result in genome instability and are a major cause of cancer predisposition and response to emerging chemotherapies. Since histone acetylation is responsive to acetyl-CoA availability and acetyl-CoA metabolism is frequently deregulated in cancer cells, we postulated that acetyl-CoA might impact H4K16ac levels at DSB sites to modulate the DNA repair efficiency. Our preliminary data shows that manipulation of nuclear-cytoplasmic acetyl-CoA levels by silencing the metabolic enzyme ATP-citrate lyase (ACLY) indeed impacts the recruitment of repair proteins to DSB sites, with recruitment of pro-NHEJ factor 53BP1 favored over pro-HR BRCA1 upon ACLY silencing. In this R21 application, we propose to test the hypothesis that oncogene-driven glucose uptake and acetyl- CoA production impact the acetylation state at DSBs and modulate the response to DNA damaging agents. We will pursue this hypothesis by first testing whether acetyl-CoA availability is indeed a critical determinant o DNA repair mechanism by affecting the balance of HR and NHEJ factors at DSBs. We will then examine the influence of altered acetyl-CoA metabolism mediated by the PI3K-Akt and LKB1-AMPK-ACC1 pathways on the DNA repair mechanism. This study has potential to identify previously unrecognized links between cellular metabolism and the DNA damage response and to identify new approaches to sensitize cells to chemotherapeutics.

 描述（由适用提供）：代谢在癌细胞中广泛冷藏以支持生物合成，生长和增殖。最近显而易见的是，许多组蛋白和DNA修饰对细胞代谢状态敏感。组蛋白乙酰化是动态染色质的修饰，组蛋白乙酰化的全球水平对代谢物乙酰-COA的可用性有反应。然而，组蛋白乙酰化的代谢控制的功能意义仍然很少了解。韦尔伦实验室最近表明，癌细胞中PI3K-AKT途径的致癌激活促进乙酰-COA的产生和组蛋白乙酰化水平升高，表明在癌细胞中，组蛋白乙酰化的正常代谢对照在癌细胞中受到破坏。包括组蛋白乙酰化在内的广泛的染色质修饰在DNA修复的调节中起着至关重要的作用。格林伯格实验室最近表明，在DNA双链断裂（DSB）部位，组蛋白H4赖氨酸16（H4K16AC）的乙酰化在募集DNA修复蛋白（如BRCA1）（例如BRCA1）（例如BRCA1）和DNA修复机制的利用中起关键作用。 DSB通过同源重组（HR）或非理论端连接（NHEJ）修复。人力资源缺陷（例如BRCA1/2突变发生）导致基因组不稳定性，是癌症易感性和对新兴化学疗法反应的主要原因。由于组蛋白乙酰化对乙酰-COA的可利用率有反应，并且乙酰-COA代谢在癌细胞中经常受到失控，因此我们假设乙酰-COA可能会影响DSB位点的H4K16AC水平，以调节DNA修复效率。我们的初步数据表明，通过沉默的代谢酶ATP-CITRATE裂解酸酯（ACLY）确实会影响将修复蛋白募集到DSB地点，而通过Pro-NHEJ因子53BP1招募Pro-HR BrcaLe silencing，对DSB的维修蛋白募集到DSB地点，从而对核周质乙酰-COA水平进行操纵。在此R21应用中，我们建议检验以下假设：癌基因驱动的葡萄糖摄取和乙酰基-COA的产生影响DSB处的乙酰-COA态并调节对DNA损伤剂的响应。我们将通过首先测试乙酰辅酶A的可用性是否确实是一种急切确定的ODNA修复机制来追求这一假设，该假设是否是通过影响DSBS的HR和NHEJ因子的平衡来确定的。然后，我们将研究由PI3K-AKT和LKB1-AMPK-ACC1途径介导的改变的乙酰-COA代谢对DNA修复机制的影响。这项研究具有鉴定细胞代谢与DNA损伤反应之间的先前未识别的联系，并确定对化学疗法敏感性细胞的新方法。