Epigenetic regulation of cancer metabolism by G9A

G9A 对癌症代谢的表观遗传调控

• 批准号: 9323351
• 负责人: HAN-FEI DING
• 金额: $ 31.54万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9323351
• 关键词: Anabolism; Binding; Biochemical Reaction; Biological Assay; Cancer Cell Growth; Cell Proliferation; Coenzymes; DNA Binding; DNA Binding Domain; Dependence; Drug Targeting; Epigenetic Process; Flavin-Adenine Dinucleotide; Genes; Genetic Transcription; Glycine; Goals; Growth; Histone H3; Histone-Lysine N-Methyltransferase; Histones; Human; Investigation; KDM1A gene; Lead; Lysine; MYCN gene; Malignant Neoplasms; Membrane Lipids; Metabolic; Metabolism; Methylation; Methyltransferase; Modeling; Molecular; Molecular Target; Nucleic Acids; Outcome; Pathway interactions; Production; Proteins; Recruitment Activity; Regulation; Research; Role; S-Adenosylmethionine; Serine; Starvation; Testing; Transactivation; Transcriptional Activation; Transcriptional Regulation; anticancer research; cancer cell; demethylation; epigenetic regulation; macromolecule; methyl group; novel drug class; overexpression; promoter; public health relevance; response; targeted cancer therapy; transcription factor; tumor metabolism

DESCRIPTION (provided by applicant): Cancer cells reprogram their metabolism to meet the biosynthetic challenge of growth and proliferation. How cancer metabolism is initiated and maintained in cancer cells is a central question of cancer research. Recent studies demonstrate that increased activation of the serine-glycine synthesis pathway, which generates many biosynthetic precursors and metabolites essential for the production of proteins, lipid membranes and nucleic acids, is an integral part of cancer metabolism. We recently uncovered an essential role of the histone H3 lysine 9 (H3K9) methyltransferase G9A in epigenetic activation of this biosynthesis pathway. G9A has a primary role in catalyzing H3K9 monomethylation and dimethylation (H3K9me1 and H3K9me2), with H3K9me1 being an active mark and H3K9me2 being a repressive mark. G9A overexpression has been observed in many types of human cancers. We found that G9A transcriptionally activates serine-glycine synthesis by increasing H3K9me1 at the promoters of the pathway genes. The proposed research is to determine 1) how G9A is specifically targeted to the pathway genes, given that G9A has no sequence-specific DNA-binding domain, and 2) how G9A specifically marks these genes with H3K9me1, given that G9A can catalyze both H3K9me1 and H3K9me2. In Aim 1, we will investigate the sequence-specific DNA-binding transcription factor ATF4 as a mechanism for targeting G9A to the promoters of the serine pathway genes. We will determine whether ATF4 is required for G9A to bind to these promoters, to modulate their H3K9 methylation states, and to increase glycolic flux for serine-glycine synthesis. We will also investigate the molecular basis o the G9A-ATF4 interaction. In Aim 2, we will investigate the transcription factor MYCN as an alternative mechanism for targeting G9A to the serine pathway genes, particularly in cancer cells with G9A overexpression. We will determine whether MYCN is required for G9A to bind to these gene promoters, to modulate their H3K9 methylation states, and to increase glycolic flux for serine-glycine synthesis. We will also investigate the molecular basis of the G9A-MYCN interaction. In Aim 3, we will test the hypothesis that the H3K9 demethylase KDM4C, which specifically removes H3K9me2 and H3K9me3, cooperates with G9A to maintain high levels of H3K9me1 at these gene promoters. We will determine whether G9A and KDM4C bind simultaneously to these gene promoters and whether G9A requires KDM4C to maintain high-level H3K9me1 at these promoters for transcriptional activation. We will also investigate the molecular basis of the G9A-KDM4C cooperation. The proposed investigation is anticipated to identify a new regulatory mechanism for the control of serine-glycine synthesis and to introduce a new avenue to target cancer metabolism for therapy. Additionally, functional assays of

描述（由申请人提供）：癌细胞重新编程其新陈代谢，以满足生长和增殖的生物合成挑战。癌细胞中癌症代谢如何启动和维持是癌症研究的核心问题。最近的研究表明，丝氨酸-甘氨酸合成途径的激活增加是癌症代谢的一个组成部分，该途径产生许多生物合成前体和代谢物，这些前体和代谢物对于蛋白质、脂质膜和核酸的产生至关重要。我们最近发现了组蛋白 H3 赖氨酸 9 (H3K9) 甲基转移酶 G9A 在该生物合成途径的表观遗传激活中的重要作用。 G9A 在催化 H3K9 单甲基化和二甲基化（H3K9me1 和 H3K9me2）中起主要作用，其中 H3K9me1 是活性标记，H3K9me2 是抑制标记。在许多类型的人类癌症中都观察到 G9A 过度表达。我们发现 G9A 通过增加途径基因启动子处的 H3K9me1 转录激活丝氨酸-甘氨酸合成。拟议的研究旨在确定 1) 鉴于 G9A 没有序列特异性 DNA 结合域，G9A 如何特异性靶向通路基因；2) 鉴于 G9A 可以催化 H3K9me1 和 H3K9me2，G9A 如何用 H3K9me1 特异性标记这些基因。在目标 1 中，我们将研究序列特异性 DNA 结合转录因子 ATF4 作为将 G9A 靶向丝氨酸途径基因启动子的机制。我们将确定 G9A 是否需要 ATF4 才能与这些启动子结合、调节其 H3K9 甲基化状态以及增加丝氨酸-甘氨酸合成的乙醇通量。我们还将研究 G9A-ATF4 相互作用的分子基础。在目标 2 中，我们将研究转录因子 MYCN 作为将 G9A 靶向丝氨酸途径基因的替代机制，特别是在 G9A 过度表达的癌细胞中。我们将确定 G9A 是否需要 MYCN 才能与这些基因启动子结合、调节其 H3K9 甲基化状态以及增加丝氨酸-甘氨酸合成的乙醇通量。我们还将研究 G9A-MYCN 相互作用的分子基础。在目标 3 中，我们将测试以下假设：H3K9 去甲基化酶 KDM4C（专门去除 H3K9me2 和 H3K9me3）与 G9A 合作，在这些基因启动子处维持高水平的 H3K9me1。我们将确定 G9A 和 KDM4C 是否同时与这些基因启动子结合，以及 G9A 是否需要 KDM4C 在这些启动子处维持高水平的 H3K9me1 以进行转录激活。我们还将研究 G9A-KDM4C 合作的分子基础。拟议的研究预计将确定一种控制丝氨酸-甘氨酸合成的新调节机制，并引入一种针对癌症代谢进行治疗的新途径。此外，功能测定