新结构组蛋白去乙酰化酶抑制剂筛选及抗肿瘤活性初步观察

组蛋白的乙酰化调节是基因表达调控的一种重要机制，它参与了机体病理、生理水平的多方面调节。组蛋白乙酰转移酶和组蛋白去乙酰化酶活性共同决定了组蛋白的乙酰化水平。组蛋白去乙酰化酶抑制剂可以提高组蛋白的乙酰化水平，从而调节某些特定基因的表达。我们建立了非同位素法高通量筛选组蛋白去乙酰化酶抑制剂的模型，筛选了约二百种化合物，发现三种能够抑制组蛋白去乙酰化酶的化合物。实验证明，它们能在细胞水平促进组蛋白的乙酰化，并对体外培养的多种肿瘤细胞具有明显的杀伤作用。初步体内实验表明，化合物H9能抑制小鼠体内肿瘤的发生、发展。新结构的组蛋白去乙酰化酶抑制剂可能具有新型抗肿瘤药物的应用前景。     

环肽类组蛋白去乙酰化酶抑制剂研究进展

组蛋白去乙酰化酶是一类对染色体结构修饰和基因表达调控具有重要作用的蛋白酶,其异常活化与肿瘤的发生、发展密切相关。抑制组蛋白去乙酰化酶活性已成为抗肿瘤治疗的有效策略之一。对组蛋白去乙酰化酶抑制剂的抗肿瘤作用机制进行介绍,并重点综述环肽类组蛋白去乙酰化酶抑制剂的研究进展,旨在为该类药物的深入开发提供参考。     

组蛋白去乙酰化酶抑制剂的抗肿瘤活性

组蛋白去乙酰化酶（HDAC）与染色质重塑有关，在基因表达的表观遗传调控中扮演重要角色。此外，HDAC介导的低乙酰化作用可调节非组蛋白活性。近年来，抑制组蛋白去乙酰化酶成为逆转与肿瘤相关的表观遗传异常改变的潜在策略。临床前研究发现，多种组蛋白去乙酰化酶抑制剂（HDACi）表现出有效的、特异的抗肿瘤活性，然而其疗效相当广泛和复杂。     

组蛋白去乙酰酶抑制剂的研究进展

组蛋白乙酰转移酶(histone acetyltransferase,HAT)和组蛋白去乙酰酶(histone deacetylase,HDAC)通过对组蛋白氮端氨基酸残基进行乙酰化或去乙酰化,调节组蛋白的乙酰化水平,调控基因表达,该过程与癌症的发生具有密切的关系.组蛋白去乙酰酶抑制剂通过增加细胞内组蛋白的乙酰化程度,提高p21等基因的表达水平等途径,抑制肿瘤细胞的增殖,诱导细胞分化和(或)凋亡.该文对HDAC抑制剂的研究进展进行系统的综述.     

组蛋白去乙酰化酶抑制剂治疗血液肿瘤研究进展

表观遗传学修饰的改变,可使基因表达异常,并促进肿瘤的发生发展.表观遗传学修饰包括DNA甲基化修饰及组蛋白修饰.由组蛋白乙酰基转移酶及组蛋白去乙酰化酶调控的乙酰化修饰,是最重要的组蛋白修饰.应用组蛋白去乙酰化酶抑制刺对其进行调控,可使肿瘤细胞生长受抑,发生凋亡,并可增强肿瘤对化疗的敏感性.单独应用组蛋白去乙酰化酶抑制剂或联合其他化疗药物,成为抗血液肿瘤研究与治疗的新方向.     

SIRT1抑制剂的研究进展

组蛋白去乙酰化是一种重要的组蛋白共价修饰方式,在基因表达中起着非常重要的调控作用.组蛋白去乙酰化主要由组蛋白去乙酰化酶催化完成,现已发现的组蛋白去乙酰化酶除了经典的锌离子依赖的组蛋白去乙酰化酶外,还有一类较为特殊的组蛋白去乙酰化酶——沉默信息调节因子2 (silent information regulator 2,Sir2)相关蛋白.     

组蛋白甲基化及乙酰化修饰酶在卵巢癌中的机制研究及治疗进展

卵巢癌是恶性程度最高的妇科恶性肿瘤。近年来,组蛋白修饰(histone modifying enzymes, HMEs)作为表观遗传修饰的重要部分在卵巢癌中被广泛研究,包括组蛋白甲基转移酶及去甲基酶、组蛋白乙酰转移酶及去乙酰化酶在内的多种组蛋白修饰酶通过对组蛋白及非组蛋白进行修饰,在卵巢癌细胞的增殖、迁移等方面发挥了重要作用,并且能够调控化疗耐药的发生。多种组蛋白修饰酶的抑制剂通过促进细胞生长停滞及凋亡、抑制肿瘤细胞的侵袭、增加化疗敏感性等在卵巢癌中发挥良好的抗肿瘤作用,有望成为卵巢癌精准治疗的新策略。本文将针对参与甲基化及乙酰化过程的组蛋白修饰酶在卵巢癌中的作用机制及治疗潜力作一综述。     

组蛋白去乙酰化酶6的结构、功能及选择性抑制剂的研究进展

组蛋白去乙酰化酶6(HDAC6)是组蛋白去乙酰化酶家族中独具特色的一员。该酶具有两个去乙酰化功能区,可特异性催化非组蛋白底物,参与并调节众多生理或病理进程。目前已报道的选择性HDAC6抑制剂结构种类较多,有的正处于临床试验阶段。本文将对HDAC6的结构、功能及其选择性抑制剂的研究进展进行综述。     

基于榄香烯结构的新型组蛋白去乙酰化酶抑制剂的设计、合成及生物学活性研究

目的 设计、合成含有榄香烯结构的新型组蛋白去乙酰化酶抑制剂(histone deacetylase inhibitor,HDA-CI),评价其体外抗肿瘤细胞增殖活性及对组蛋白去乙酰化酶的抑制活性.方法 以β-榄香烯结构作为锌离子结合型HDACI表面识别基团,分别以脂肪酸、异羟肟酸、酰胺结构片段为锌离子结合基团,设计并合...     

在治疗肿瘤领域中组蛋白去乙酰化酶抑制剂的研究进展

近年来在治疗肿瘤领域中组蛋白去乙酰化酶（HDAC）抑制剂的研究已成为热点。组蛋白乙酰化转移酶（HAT）与组蛋白去乙酰化酶（HDAC）之间保持的动态平衡调控着有序的基因表达, HDAC表达过度造成乙酰化的失衡会形成肿瘤,而HDAC抑制剂可诱导肿瘤细胞分化、细胞周期停滞和凋亡,抑制肿瘤的生成。HDAC抑制剂是很有前途的新型癌症靶向治疗药物。本文将重点阐述HDAC抑制剂的作用机制以及在肿瘤治疗领域中的研究进展。     

Effect of inhibitors of histone deacetylase on the induction of cell differentiation in murine and human erythroleukemia cell lines

Histone deacetylase (HDAC) inhibitors are a novel class of promising anti-cancer agents. Little information is available on the capacity of structurally different HDAC inhibitors to induce terminal cell differentiation in different cell types in relation to enzyme inhibition and subtype selectivity. Consequently, the aim of this study was to provide a comprehensive comparison of these effects. New biarylalanine inhibitors of HDAC were synthesized and compared to a series of standard inhibitors from different laboratories. Chromatographically purified rat liver and immunoprecipitated FLAG-tagged recombinant human HDACs were used as sources of HDAC activity. Enzyme inhibition was studied using a fluorescent substrate and its conversion was monitored by high-performance liquid chromatography. The ability to induce cell differentiation was compared in murine (Friend DS-19) and human (K562) erythroleukemic cell lines, and was quantified by benzidine staining. Inhibition of cell proliferation was evaluated by cell counting. All HDAC inhibitors were identified as potent inhibitors of erythroleukemic cell proliferation. However, we observed a complex pattern of differentiation induction: structurally similar inhibitors resulted in disparate activity profiles, whereas similar profiles were detected within distinct structural classes. Among the newly synthesized biarylalanine compounds, a 3'-methoxy derivative was identified as a very effective inducer of terminal cell differentiation. We conclude that investigation of subtype selectivity of selected HDAC inhibitors does not provide a clear link between selectivity and the observed cellular activity profile. The predictive value of in vitro HDAC inhibition assays for identifying anti-proliferative compounds has been emphasized.     

Development and therapeutic impact of HDAC6-selective inhibitors

Histone deacetylases (HDAC) play a key role in regulating gene expression by deacetylating histones. Some HDAC isoforms can also modulate the function of nonhistone proteins implicated in regulatory processes, and therefore HDACs are recognized as useful targets for therapeutic purposes. HDAC inhibitors have generated substantial interest as antitumor agents, because they induce various cellular effects, including apoptosis, cell cycle arrest and inhibition of angiogenesis. The nature of cellular response likely depends on the biological context and on the pattern of HDAC isoform inhibition. Various HDAC inhibitors belonging to different structural classes have been developed. Many inhibitors are characterized by a pan-HDAC inhibitory profile. The potential advantages of isoform-selective inhibitors over pan-HDAC inhibitors in terms of efficacy or toxicity remain to be defined. The emerging interest for HDAC6-selective inhibitors is related to the modulation of acetylation of nonhistone regulatory proteins implicated in cancer-relevant processes, including cell migration, metastasis, angiogenesis and stress-response pathways. This review is focused on the recent development of HDAC inhibitors, with particular reference to HDAC6-selective inhibitors, and the efforts and perspectives in optimization of their therapeutic applications.     

用于筛选组蛋白去乙酰化酶抑制剂细胞模型的验证

目的验证已建立的组蛋白去乙酰化酶(HDAC)抑制剂筛选细胞模型,并采用该模型进行药物筛选。方法采用脂质体转染法将含有TA1和TA2启动子元件的荧光素酶报道基因真核表达载体pTA1-Luc和pTA2-Luc导入COS-7细胞,G418筛选获得稳定转染上述报告基因系统的细胞克隆。以特异性HDAC抑制剂缩酯环肽FK228,N-辛二酰苯胺异羟肟酸(SAHA)和曲古抑菌素A(TSA)为阳性对照,通过测定荧光素酶活性评估TA1和TA2启动子对HDAC抑制剂的反应;并采用此细胞模型对其他抗肿瘤药物和植物提取物进行初步筛选。结果稳定转染的COS-pTA1及COS-pTA2细胞对HDAC抑制剂具有良好的浓度依赖性(FK228:相关系数为0.7236;SAHA:相关系数为0.7997;TSA为相关系数为0.9815;P<0.01),其中COS-pTA1的特点是灵敏度高,可以有效避免因样品活性低而出现漏检。COS-pTA2细胞的特点是检测背景低,特异性强,可以有效排除假阳性的标本。两种细胞模型的联合筛选,可以鉴定具有HDAC抑制活性的化合物。结论该细胞模型可用于筛选具有HDAC抑制活性的先导化合物。     

Non-hydroxamate histone deacetylase inhibitors

A number of histone deacetylase (HDAC) inhibitors have been developed as anticancer agents and most of them are hydroxamic acid derivatives, typified by suberoylanilide hydroxamic acid (SAHA), Trichostatin A (TSA) and NVP-LAQ824. However, hydroxamic acids have been associated with poor pharmacokinetics and severe toxicity. In addition, although isozyme-selective HDAC inhibitors are considered useful not only as tools for probing the biology of an enzyme but as drugs with low toxicity, many of the hydroxamate HDAC inhibitors do not distinguish well among the HDAC isozymes. Thus, there has been considerable interest in developing non-hydroxamate HDAC inhibitors. To date, small fatty acids, o-aminoanilides, electrophilic ketones, N-formyl hydroxylamines, thiols and mercaptoamides have been reported as non-hydroxamate HDAC inhibitors, and some of them show antiproliferative activity comparable to hydroxamates. Interestingly, hydroxamate HDAC inhibitors such as SAHA and TSA do not discriminate well among the HDAC isozymes whereas many non-hydroxamate HDAC inhibitors have shown selectivity. These non-hydroxamate HDAC inhibitors should pave the way for the development of tools for biological research and new medicines with few side effects. In this review, we introduce non-hydroxamate HDAC inhibitors describing their design, enzyme inhibition, cancer cell growth inhibition and isozyme selectivity.     

Anti-Cancer Effect of IN-2001 in T47D Human Breast Cancer

Histone deacetylases (HDACs) are enzymes involved in the remodelling of chromatin, and have a key role in the epigenetic regulation of gene expression. Histone deacetylase (HDAC) inhibitors are emerging as an exciting new class of potential anti-cancer agents. In recent years, a number of structurally diverse HDAC inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. However, the underlying molecular mechanisms remain unclear. This study aimed at investigating the anti-tumor activity of various HDAC inhibitors, IN-2001, using T47D human breast cancer cells. Moreover, the possible mechanism by which HDAC inhibitors exhibit anti-tumor activity was also explored. In estrogen receptor positive T47D cells, IN-2001, HDAC inhibitor showed anti-proliferative effects in dose-and time-dependent manner. In T47D human breast cancer cells showed anti-tumor activity of IN-2001 and the growth inhibitory effects of IN-2001 were related to the cell cycle arrest and induction of apoptosis. Flow cytometry studies revealed that IN-2001 showed accumulation of cells at G₂/M phase. At the same time, IN-2001 treatment time-dependently increased sub-G₁ population, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with induction of cdk inhibitor expression. In T47D cells, IN-2001 as well as other HDAC inhibitors treatment significantly increased p21^WAF1 and p27^KIP1 expression. In addition, thymidylate synthase, an essential enzyme for DNA replication and repair, was down-regulated by IN-2001 and other HDAC inhibitors in the T47D human breast cancer cells. In summary, IN-2001 with a higher potency than other HDAC inhibitors induced growth inhibition, cell cycle arrest, and eventual apoptosis in human breast cancer possibly through modulation of cell cycle and apoptosis regulatory proteins, such as cdk inhibitors, cyclins, and thymidylate synthase.