Development of first-in-class histone acetyltransferase (HAT) activators for precision targeting of epigenetic derangements in lymphoma

开发一流的组蛋白乙酰转移酶 (HAT) 激活剂，用于精确靶向淋巴瘤表观遗传紊乱

• 批准号: 9790953
• 负责人: Jennifer E. Amengual
• 金额: $ 35.95万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-21 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9790953
• 关键词: Acetylation; Address; Affect; Affinity; Aggressive course; Alleles; Antibody Affinity; Antibody Repertoire; Apoptosis; Automobile Driving; B-Cell Development; B-Cell Lymphomas; B-Lymphocytes; BCL6 gene; Binding; Biological; Biological Assay; Biological Markers; Biophysics; Cell Cycle; Cell Death; Cell Line; Cells; Chromatin; Clinical; Clinical Trials; DNA Modification Methylases; DNA Repair; Deacetylase; Development; Disease; EP300 gene; EZH2 gene; Enzymes; Epigenetic Process; Evaluation; Event; Exposure to; Expression Profiling; Functional disorder; Gene Expression; Gene Expression Profile; Gene Mutation; Gene Silencing; Genes; Genetic Transcription; Germinal Center B-Lymphocyte; Goals; Histone Acetylation; Histone Deacetylase; Histone Deacetylase Inhibitor; Histone Deacetylation; Histones; Humoral Immunities; Immunoglobulin Class Switching; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Laboratories; Lead; Legal patent; Length; Libraries; Link; Lymphoma; Lymphomagenesis; Mass Spectrum Analysis; Mediating; Methylation; Methyltransferase; Modification; Molecular; Molecular Target; Mus; Mutagenesis; Mutation; Pathogenesis; Patients; Pharmaceutical Preparations; Pharmacology; Physiological; Post-Translational Protein Processing; Process; Property; Reaction; Recombinants; Sampling; Structure; Structure of germinal center of lymph node; TP53 gene; Therapeutic; Therapeutic Effect; Transcription Repressor/Corepressor; Transcriptional Activation; Translating; Tumor Suppressor Proteins; Xenograft procedure; analog; biophysical properties; chemical group; epigenetic therapy; gain of function; gene repression; genetic signature; histone acetyltransferase; histone methylation; histone methyltransferase; improved; inhibitor/antagonist; insight; large cell Diffuse non-Hodgkin' s lymphoma; lead candidate; lenalidomide; lymph nodes; molecular subtypes; mouse model; mutational status; nano-string; novel; novel strategies; off-patent; operation; pre-clinical; predicting response; predictive marker; recruit; response; response biomarker; success; synergism

Diffuse large B-cell lymphoma (DLCBL) is the most common type of lymphoma affecting ~30,000 patients annually. Recent insights into the molecular pathogenesis of DLBCL has divided this disease into two molecular subtypes: germinal center (GC) and ABC subtypes. Targeting molecular features of ABC-DLCBL are in the final stages of development, but such success has not been realized for the more common GC-DLCBL. The GC is a compartment of the lymph node responsible for generating high affinity antibodies via somatic hyper-mutation and class switch recombination. Epigenetic modifiers such as EZH2, histone acetyltransferases (HATs), and the transcriptional repressor, Bcl6, are essential to B-cell development allowing for requisite mutagenesis and silencing of tumor suppressors necessary for somatic hypermutation. This physiologic state is partly achieved by decreased acetylation and increased methylation of histones enforcing a transcriptionally repressed state. Mutations affecting these epigenetic and transcriptional modifiers, HATs, EZH2 and Bcl6, have been identified as driving events in GC-derived lymphomas. Given the critical importance of epigenetic dysfunction in the pathogenesis of GC-derived B-cell lymphomas, we hypothesize that if inactivating mutations in HAT alleles are crucial to GC-DLBCL then drugs activating the wild-type enzyme should demonstrate therapeutic effect. In addition, we believe that combined targeting of epigenetic machinery with HAT activators and other epigenetic modifying agents (HDAC and EZH2 inhibitors) may induce profound epigenetic modification leading to synergistic induction of programmed cell death. Finally, if mutational status and expression levels of specific genes such as EP300 correlate with response to HAT activators or combined epigenetic therapy, then a NanoString expression panel may be developed as a biomarker for response. The objectives of this proposal will be evaluated by addressing the following specific aims: (1) Characterize the HAT activator YF2 by determining binding to HAT enzymes and its functional effects on acetylation in cell- free assays. (2) Determine the effects of HAT activators in combination with clinically available epigenetic modifying agents in cell lines and mice. Epigenetic modifying agents will include HDAC and EZH2 inhibitors. The effects of HAT activators in combination with epigenetic modifying agents on post-translational modifications (methylation, acetylation), and gene expression of downstream targets will be determined. (3) Interrogate the mutational status of EP300 and epigenetic gene signatures of lymphoma cell lines to inform precision targeting with HAT activators. Basal gene mutation and expression profiles will be determined for candidate epigenetic and transcriptional modifiers in lymphoma cell lines and will be correlated to the IC50 of HAT activators and the synergy coefficients of combined epigenetic therapy. Should we accept these hypotheses, this would represent an opportunity to directly target mutations, such as HAT and EZH2, which drive GC-DLBCL.

弥漫性大B细胞淋巴瘤（DLCBL）是影响约30,000例患者的最常见淋巴瘤类型 每年。对DLBCL分子发病机理的最新见解已将该疾病分为两种分子 亚型：生发中心（GC）和ABC亚型。靶向ABC-DLCBL的分子特征是最终的 开发阶段，但对于更常见的GC-DLCBL尚未实现这种成功。 GC是一个 淋巴结的隔室，负责通过躯体超女的高亲和力产生高亲和力 和类开关重组。表观遗传修饰符，例如EZH2，组蛋白乙酰转移酶（帽子）和 转录阻遏物Bcl6对于B细胞的发展至关重要，允许必要的诱变和沉默 肿瘤抑制器的体细胞超成熟所必需的。这种生理状态部分由 乙酰化降低并增加组蛋白的甲基化，从而实施转录抑制状态。 影响这些表观遗传和转录修饰剂的突变，HATS，EZH2和BCL6已被确定为 GC衍生的淋巴瘤中的驾驶事件。 鉴于表观遗传功能障碍在GC衍生的B细胞淋巴瘤的发病机理中的重要性， 我们假设，如果帽子等位基因中的灭活突变对GC-DLBCL至关重要，那么药物会激活该药物 野生型酶应表现出治疗作用。此外，我们认为合并的定位 带有HAT激活剂和其他表观遗传修饰剂（HDAC和EZH2抑制剂）的表观遗传机制 可能引起深刻的表观遗传修饰，从而导致程序性细胞死亡的协同诱导。最后， 如果特定基因（例如EP300）的突变状态和表达水平与对HAT的反应相关 激活剂或联合表观遗传疗法，则可以开发纳米弦表达面板作为一种 生物标志物的反应。 该提案的目标将通过解决以下特定目的来评估：（1）表征 HAT激活剂YF2通过确定与HAT酶的结合及其对细胞中乙酰化的功能作用 免费测定。 （2）确定帽子激活剂与临床上可用的表观遗传学的影响 修饰细胞系和小鼠中的剂。表观遗传修饰剂将包括HDAC和EZH2抑制剂。 帽子激活剂与表观遗传修饰剂对翻译后的影响 将确定修饰（甲基化，乙酰化）和下游靶标的基因表达。 （3） 询问EP300的突变状态和淋巴瘤细胞系的表观遗传基因特征，以告知精度 用帽子激活器定位。将确定候选者的基础基因突变和表达谱 淋巴瘤细胞系中的表观遗传和转录修饰剂，并将与HAT激活剂的IC50相关 以及联合表观遗传疗法的协同系数。如果我们接受这些假设，这将 代表了直接靶向驱动GC-DLBCL的HAT和EZH2等直接靶向突变的机会。