Clinical Investigation of Epigenetic Therapy

关键抑癌基因的表观遗传转录沉默在许多恶性肿瘤中的作用已被证实 久负盛名。导致这种转录沉默的分子机制已经开始 过去几年的研究发现，导致了DNA甲基化以一种动态的方式相互作用的概念 核组蛋白和基于BRG1和hBrm的SWI/SNF复合体抑制或增强的途径 抄写。慢性淋巴细胞白血病(CLL)的临床前研究已经证明了这些机制 事实上，基因沉默在临床上是相关的，并且针对不止一种基因沉默机制 导致协同基因再表达和伴随的细胞凋亡。更多的研究表明 这些药物激活不常用的可选的凋亡途径的能力 CLL的化疗或免疫治疗，以及上调作为潜在分子的细胞表面抗原 治疗靶点。这项翻译研究项目的总体假设是应用 针对染色质结构变化的表观遗传疗法将减轻异常转录 抑制肿瘤抑制基因，恢复正常的细胞增殖、分化和 细胞凋亡，最终使慢性淋巴细胞性白血病患者临床受益。对这些的理性评价 药物将需要详细研究这些药物在肿瘤样本和体内的一系列生物效应。AS 因此，在评论家的建议下，我们的研究将只集中在对外汉语教学上。我们的数据支持详细的 慢性淋巴细胞性白血病表观遗传学治疗的研究 治疗期间多个时间点血液中的肿瘤细胞数。这项建议的具体目标是： 1)对联合利妥昔单抗治疗卵巢癌的患者进行L/11期研究。 氟达拉滨-难治性CLL。这项研究将伴随着详细的机制研究，以评估 组蛋白脱乙酰酶抑制的动力学、组蛋白脱乙酰酶抑制调控的靶点及其机制 对脱氧核糖肽的耐药性。2)进行最小有效药理剂量发现研究 地西他滨联合丙戊酸治疗氟达拉滨难治性慢性淋巴细胞性白血病 确定这两种疗法的临床和基因再表达疗效的随机II期研究 接近了。3)同时进行详细的药理学和药效学研究，作为目标的一部分 2例临床试验。这些目标的发展在很大程度上依赖于基本目标的投入 科学项目，如确定目标基因(特别是项目2和3)，确定 组蛋白修饰(项目4)，以及基于Brgland hBrm的SWI/SNF复合体的重要性(项目5) 调节在此提出的表观遗传靶向治疗的生物学效应。此外，调查结果显示， 从这个翻译指导的项目派生出来的，已经为新的假设做出了贡献，将在 项目2-5中的实验室，如他们的每个提案中所概述的。

The role of epigenetic transcriptional silencing of key tumor suppressor genes in many malignancies has been well established. The molecular mechanisms leading to this transcriptional silencing have begun to be lucidated over the last several years, leading to the concept that methylation of DNA interacts in a dynamic way with nuclear histones and Brg1- and hBrm-based SWI/SNF complexes to either repress or enhance transcription. Pre-clinical work in Chronic Lymphocytic Leukemia (CLL) has demonstrated these mechanisms of gene silencing are in fact clinically relevant, and that targeting more than one mechanism of gene silencing results in synergistic gene re-expression and concomitant apoptosis. Additional studies have demonstrated the ability of these agents to both activate alternative pathways of apoptosis not commonly utilized by chemotherapy or immunotherapy in CLL, and to up-regulate cell surface antigens that are potential molecular therapeutic targets. The overall hypothesis of this translational research Project is that application of epigenetic therapy targeting chromatin structure changes will relieve aberrant transcriptional repression of tumor suppressor genes, restore normal patterns of cell proliferation, differentiation and apoptosis, and ultimately result in clinical benefit to patients with CLL. The rational evaluation of these agents will require detailed study of the serial biologic effect of these agents in tumor samples and in vivo. As suggested by the reviewers, our research therefore will focus on CLL only. Our data support a detailed investigation of epigenetic therapy in CLL; furthermore, this disease provides the ability to isolate a large number of tumor cells from the blood at multiple points during treatment. The specific aims of this proposal are: 1) To perform a phase l/ll study of a novel schedule of depsipeptide combined with rituximab in patients with fludarabine-refractory CLL. This study will be accompanied by detailed mechanistic studies to assess the kinetics of histone deacetylase inhibition, targets modulated by histone deacetylase inhibition, and mechanisms of resistance to depsipeptide. 2) To perform a minimum effective pharmacologic dose-finding study of decitabine and then decitabine combined with valproic acid in fludarabine refractory CLL patients, followed by a randomized phase II study to determine the clinical and gene re-expression efficacy of these two therapeutic approaches. 3) To perform concurrent detailed pharmacologic and pharmacodynamic studies as part of the Aim 2 clinical trial. The development of each of these aims has been heavily dependent on the input of the basic science Projects, such as for the determination of target genes (particularly Projects 2 and 3), identification of histone modifications (Project 4), and importance of Brgland hBrm based SWI/SNF complexes (Project 5) in mediating the biologic effect of the epigenetically targeted therapies proposed herein. In addition, the findings derived from this translationally directed Project have already contributed to new hypotheses to be tested in the laboratory in Projects 2-5, as outlined in each of their proposals.