组蛋白去乙酰化酶抑制剂SAHA体外抑制人卵巢癌SKOV3细胞的实验研究

  目的   目的: 观察组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸(suberoylanilide hydroxamic acid, SAHA) 体外对人卵巢癌SKOV3细胞增殖和凋亡的作用, 并探讨其可能机制。   方法  体外应用SAHA作用于人卵巢癌SKOV3细胞, MTT法检测细胞增殖, 流式细胞术检测细胞凋亡率。Western blot法检测细胞内组蛋白H4乙酰化水平, 实时定量PCR方法检测p21、Bcl-2和Bax基因mRNA表达。   结果  经SAHA作用后的人卵巢癌SKOV3细胞生长受到抑制, 细胞凋亡增加(各实验组与对照组比较, 均P < 0.05), 呈剂量依赖性; 同时细胞内组蛋白H4乙酰化水平增加, p21基因和Bax基因mRNA表达增加(各实验组与对照组比较, 均P < 0.05), 呈剂量依赖性, Bcl-2基因表达无明显变化(各实验组与对照组比较, 均P > 0.05)。   结论  SAHA体外可抑制人卵巢癌SKOV3细胞增殖和诱导SKOV3细胞凋亡, 提高组蛋白乙酰化水平, 增加p21和Bax基因表达可能是其作用机制之一。      

辛二酰苯胺异羟肟酸（SAHA）对乳腺癌细胞增殖影响的动物实验研究

目的探讨组蛋白去乙酰化酶抑制剂SAHA对乳腺癌细胞株增殖周期的影响。方法饲养Balb/c-nu/nu雌性裸鼠,细胞悬液皮下注射法构建人乳腺癌细胞株MCF-7裸鼠移植瘤模型,随机分为6组,经尾静脉注射不同剂量的SAHA,获取血细胞分析、血脂、肝功能、肾功能、裸鼠体重、瘤重等数据,计算肿瘤生长抑制率、移植瘤的体积,进行统计分析。结果不同剂量的SAHA作用于乳腺癌荷瘤裸鼠后,通过比较肿瘤体积及抑瘤率均显示出疗效,在0.10~0.42 mg/kg剂量范围内,SAHA的治疗效应呈现剂量依赖关系;其作用后导致血清胆红素和谷丙转氨酶水平升高,对红细胞、白细胞及血小板计数、尿素氮、肌酐水平影响不明显。结论 SAHA是乳腺癌细胞增殖抑制剂,其抑制效应有一定的量效关系;其对机体副作用较小。     

调控组蛋白乙酰化水平抑制膀胱癌细胞增殖的实验研究

背景与目的： 探讨组蛋白去乙酰化酶抑制剂磺胺酰基苯胺复合物(sulfonamide anilimde compound, Compound)对人膀胱癌细胞BIU-87的杀伤作用和机制。 材料与方法： 以不同浓度的Compound和羟基喜树碱(HCPT)作用于体外培养的膀胱癌BIU-87细胞株;采用MTT法检测细胞生长抑制率;以流式细胞术测定不同浓度的Compound和HCPT作用前后膀胱癌细胞的调亡情况及细胞周期的变化;应用RT-PCR分析Compound和HCPT作用前后膀胱癌细胞中P21waf/cif1 mRNA表达的变化。 结果： Compound和HCPT在微摩尔级浓度即能有效抑制BIU-87细胞增殖,而Compound抑制BIU-87细胞增殖的效果更明显。流式细胞术测定结果表明Compound能显著诱导细胞发生调亡,且主要诱导G1期细胞发生调亡而出现调亡峰,HCPT也诱导细胞发生调亡,但是没有出现明显的调亡峰。RT-PCR结果示Compound和HCPT能显著诱导P21waf/cif1 mRNA表达。实时定量PCR分析显示,经Compound处理的BIU-87细胞能诱导P21waf/cif1 mRNA定量表达。上述结果均呈现出明显的量-效与时-效关系。 结论： Compound在体外能有效抑制对传统化疗耐药的人膀胱癌细胞生长,其抗肿瘤生长机制可能是通过上调P21waf/cif1 mRNA水平从而使细胞阻滞于G1期所致。     

三阴性乳腺癌和组蛋白乙酰化调控的研究进展

乳腺癌是女性常见的恶性肿瘤之一,在西方国家居女性恶性肿瘤发病率的首位,其中三阴性乳腺癌（triple—negative breast cancer,TNBC）的发病年龄轻,肿瘤直径较大,临床分期较晚,局部复发及远处转移率高,预后差,是近几年来比较受关注的乳腺癌类型。组蛋白的乙酰化和去乙酰化修饰影响到染色质重塑,在基因表达的表观遗传调控中扮演重要角色,研究证实TNBC的发生发展与组蛋白去乙酰化酶（histone deacetylases,HDACs）有一定的相关性,组蛋白去乙酰化酶抑制剂（histone deacetylase inhibitor,HDA．CI）靶向抑制HDAC,可以抑制乳腺癌细胞的增殖,增加其对化疗的敏感性,提示HDACI可能成为今后治疗TNBC的一个新的发展方向。     

组蛋白去乙酰化酶抑制剂辛二酰-双羟肟酸对乳腺癌细胞增殖的影响

背景与目的:目前乳腺癌发病率仍居首位,是严重威胁女性健康的主要肿瘤之一。组蛋白去乙酰化酶抑制剂辛二酰双羟肟酸(suberic bishydroxamate,suberoyl bishydroxamic acid,SBHA)能够抑制组蛋白去乙酰化酶(histone deacetylase,HDAC)中的HDAC1和HDAC3的活性,选择性抑制某些肿瘤的生长而对正常细胞无不良反应。本实验旨在研究SBHA对人乳腺癌细胞增殖及周期的影响。方法:将不同浓度的SBHA以不同时间作用于乳腺癌MCF-7及MDA-MB-231细胞,用WST-8法检测其对细胞增殖能力的影响;用相差显微镜观察药物对细胞形态学变化;用流式细胞仪分析细胞周期。结果:SBHA呈时间和剂量依赖性抑制乳腺癌细胞增殖,使细胞形态发生明显变化,明显使G0～G1期细胞比例增高,S期细胞比例降低,与对照组比较差异有统计学意义(P>0.05)。结论:SBHA具有抑制人乳腺癌细胞增殖作用,使细胞阻滞在G0～G1期。     

组蛋白去乙酰化酶抑制剂联合化疗对乳腺癌细胞增殖影响的动物实验研究

目的：通过动物模型研究组蛋白去乙酰化酶抑制剂联合化疗对乳腺癌细胞株增殖周期的影响。方法：饲养Balb/c-nu/nu雌性裸鼠,细胞悬液皮下注射法构建人乳腺癌细胞株MCF-7裸鼠移植瘤模型,随机分为6组 （对照组、组蛋白去乙酰化酶抑制剂SAHA组、紫杉醇组、阿霉素组、紫杉醇加SAHA组、阿霉素加SAHA组）,经尾静脉注射,获取血细胞（白细胞、红细胞、血小板）、血脂（胆固醇）、肝功能（血清谷丙转氨酶、血清胆红素）、肾功能（尿素氮、 肌酐）、裸鼠体重、瘤重等数据,计算肿瘤生长抑制率、移植瘤的体积,进行统计学分析。结果：与对照组比,各治疗组均显示出肿瘤体积的缩小及肿瘤生长抑制率增加 （P<0.05）;在治疗组间两两相比,紫杉醇加SAHA组显示出最大程度的肿瘤体积的缩小及肿瘤生长抑制率增加 （P<0.05）,在含有化疗药物紫杉醇或者阿霉素的治疗组中, 均出现裸鼠体重下降、白细胞计数下降、血清谷丙转氨酶水平升高、血清胆红素水平升高（P<0.05）;在单一的紫杉醇（或者阿霉素）组与紫杉醇（或者阿霉素）联合SAHA的比较中,这四项指标均未显示出差异（P>0.05）。结论：在动物模型实验中,SAHA与化疗药物紫杉醇（或者阿霉素）联合治疗乳腺癌能协同增效且未增加副作用,有望成为乳腺癌的治疗新途径。     

组蛋白去乙酰化酶抑制剂治疗乳腺癌的临床研究

组蛋白去乙酰化酶抑制剂（histone deacetylase inhibitors,HDACIs）作为第一个成功用于癌症治疗的表观遗传学相关药物,能够有效解除对抑癌基因转录的阻滞,已成为极具潜力的抗癌药物。近年来,HDACIs在乳腺癌治疗领域中的临床研究逐渐开展,已有个别HDACIs在大型临床研究中表现出较强的抗癌活性。本文针对HDACIs在乳腺癌治疗领域开展的临床研究作一综述,有利于临床医师更好的了解HDACIs在乳腺癌治疗中的现状与进展。     

组蛋白去乙酰化酶4与乳腺癌关系的研究进展

近年来,随着表观遗传学研究的不断深入,研究者发现蛋白质翻译后修饰可调控肿瘤的发展过程,其中蛋白质乙酰化修饰是受组蛋白乙酰化/去乙酰化介导,二者通过组蛋白乙酰转移酶和组蛋白去乙酰化酶的动态精细调节,实现相互转化,对基因表达调控发挥重要作用。组蛋白去乙酰化酶4(HDAC4)是组蛋白去乙酰化酶Ⅱa类家族成员,可以使组蛋白发生去乙酰化、抑制基因的转录等。目前HDAC4表达异常已经在肝癌、胃癌、乳腺癌、胰腺癌和膀胱癌等多种恶性肿瘤中证实,并与肿瘤的发生发展密切相关。乳腺癌是女性最常见的实体瘤之一,HDAC4可通过多种途径参与乳腺癌细胞的增殖、侵袭、凋亡等。本文主要对HDAC4与乳腺癌关系的研究进行总结,以期为临床治疗乳腺癌分子作用靶点的应用前景和可能面临的挑战提供参考。     

组蛋白去乙酰化酶抑制剂联合紫杉醇抑制宫颈癌细胞增殖的体外实验

目的：研究组蛋白去乙酰化酶抑制剂SAHA联合紫杉醇对宫颈癌HeLa细胞增殖的抑制效果及其机制。方法：设置空白对照组、紫杉醇（10 nmol/L）、SAHA（10 μmol/L）、紫杉醇（10 nmol/L）+SAHA（10 μmol/L）联合组,采用四甲基噻唑蓝（MTT）法检测各组HeLa细胞的生长抑制率,计算紫杉醇对HeLa细胞的IC₅₀。RT-PCR法检测各组HeLa细胞中抑癌基因p27 mRNA的相对表达,Western blot检测HeLa细胞乙酰化组蛋白H4（Ac-H4）的表达。结果：紫杉醇、SAHA、紫杉醇+SAHA联合组处理HeLa细胞24 h的相对抑制率分别为25.93%±5.32%、46.38%±3.66%、54.27%±4.02%,联合组抑制率与紫杉醇组相比明显升高,差异具有统计学意义（P < 0.01）;48 h的抑制率分别为29.12%±3.09%、65.26%±3.03%、77.02%±3.86%,联合组抑制率最强,显著高于SAHA组和紫杉醇组（P < 0.01）。经SAHA预处理后紫杉醇对HeLa细胞的IC₅₀较单独紫杉醇组均显著下降（P < 0.05或P < 0.01）。紫杉醇组、SAHA组、紫杉醇+SAHA联合组细胞中p27 mRNA的相对表达量分别为5.845±0.548、0.978±0.117和10.601±0.673,乙酰化组蛋白H4（Ac-H4）的相对表达分别为0.878±0.068、1.148±0.018、1.282±0.033,联合组中表达量均显著高于SAHA组和紫杉醇组（P均 < 0.01）。结论：SAHA联合紫杉醇在体外能显著抑制宫颈癌细胞HeLa的增殖,增强组蛋白乙酰化水平,诱导抑癌基因的表达。     

组蛋白去乙酰化酶抑制剂在HR阳性HER-2阴性晚期乳腺癌的研究进展

组蛋白去乙酰化酶（histone deacetylase,HDAC）是可调节表观遗传学改变的组蛋白修饰酶,在一些肿瘤中HDACs被异常激活,与肿瘤进展和耐药密切相关。HDAC抑制剂（HDAC inhibitor,HDACi）通过调节肿瘤细胞的表观遗传属性,靶向性控制肿瘤细胞增殖、调节肿瘤细胞周期及修复DNA损伤。HDACi可抑制多个乳腺癌致癌信号通路,从而有可能逆转激素受体（hormone receptor,HR）阳性HER-2阴性乳腺癌的治疗耐药。本文将对HDACi在HR阳性HER-2阴性晚期乳腺癌治疗方面进行综述,探讨其在乳腺癌治疗领域中的应用前景。     

Targeting triple-negative breast cancer cells with the histone deacetylase inhibitor panobinostat

Introduction

Of the more than one million global cases of breast cancer diagnosed each year, approximately fifteen percent are characterized as triple-negative, lacking the estrogen, progesterone, and Her2/neu receptors. Lack of effective therapies, younger age at onset, and early metastatic spread have contributed to the poor prognoses and outcomes associated with these malignancies. Here, we investigate the ability of the histone deacetylase inhibitor panobinostat (LBH589) to selectively target triple-negative breast cancer (TNBC) cell proliferation and survival in vitro and tumorigenesis in vivo.

Methods

TNBC cell lines MDA-MB-157, MDA-MB-231, MDA-MB-468, and BT-549 were treated with nanomolar (nM) quantities of panobinostat. Relevant histone acetylation was verified by flow cytometry and immunofluorescent imaging. Assays for trypan blue viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) proliferation, and DNA fragmentation were used to evaluate overall cellular toxicity. Changes in cell cycle progression were assessed with propidium iodide flow cytometry. Additionally, qPCR arrays were used to probe MDA-MB-231 cells for panobinostat-induced changes in cancer biomarkers and signaling pathways. Orthotopic MDA-MB-231 and BT-549 mouse xenograft models were used to assess the effects of panobinostat on tumorigenesis. Lastly, flow cytometry, ELISA, and immunohistochemical staining were applied to detect changes in cadherin-1, E-cadherin (CDH1) protein expression and the results paired with confocal microscopy in order to examine changes in cell morphology.

Results

Panobinostat treatment increased histone acetylation, decreased cell proliferation and survival, and blocked cell cycle progression at G2/M with a concurrent decrease in S phase in all TNBC cell lines. Treatment also resulted in apoptosis induction at 24 hours in all lines except the MDA-MB-468 cell line. MDA-MB-231 and BT-549 tumor formation was significantly inhibited by panobinostat (10 mg/kg/day) in mice. Additionally, panobinostat up-regulated CDH1 protein in vitro and in vivo and induced cell morphology changes in MDA-MB-231 cells consistent with reversal of the mesenchymal phenotype.

Conclusions

This study revealed that panobinostat is overtly toxic to TNBC cells in vitro and decreases tumorigenesis in vivo. Additionally, treatment up-regulated anti-proliferative, tumor suppressor, and epithelial marker genes in MDA-MB-231 cells and initiated a partial reversal of the epithelial-to-mesenchymal transition. Our results demonstrate a potential therapeutic role of panobinostat in targeting aggressive triple-negative breast cancer cell types.     

CXCL12受体抑制剂调控三阴性乳腺癌放射治疗的敏感性

目的 探讨趋化因子12（CXCL12）受体CXCR4抑制剂AMD3100对人乳腺癌MDA-MB 231细胞裸鼠移植瘤的放射增敏效应及其作用机制。方法 建立人乳腺癌裸鼠移植瘤模型,并随机分为4组：对照组、AMD3100处理组、放射治疗组和联合治疗组（AMD3100+放疗）;称量肿瘤的重量并测量移植瘤的体积,计算放射增敏比,绘制肿瘤生长曲线;实时荧光定量PCR（QPCR）检测CXCR4和表皮生长因子受体（EGFR）基因表达;蛋白质印迹法检测CXCR4、EGFR和基质金属蛋白酶-9（MMP-9）蛋白表达。结果 经统计CXCR4抑制剂AMD3100的放射增敏比为1:45。QPCR结果显示,与对照组比较,CXCR4和EGFR基因的相对表达量在AMD3100处理组、放射治疗组及联合治疗组分别下调60％、45％、82％和56％、48％、73％,差异有统计学意义（P＜0.05）。单纯AMD3100治疗或者放射治疗均能使CXCR4、EGFR表达下调（P＜0.05）,联合治疗较单纯AMD3100治疗和放疗更能显著地抑制CXCR4和EGFR的表达（P＜0.05）。Western blotting结果显示,与对照组比较,CXCR4、EGFR及MMP-9在AMD3100处理组、放射治疗组及联合治疗组中的蛋白相对表达量均下调（P＜0.05）。AMD3100与放疗均可抑制CXCR4、EGFR及MMP-9的表达,两者联用较单一治疗的效果更加显著（P＜0.05）。     

Epigenetic reprogramming of epithelial mesenchymal transition in triple negative breast cancer cells with DNA methyltransferase and histone deacetylase inhibitors

Background

Triple negative breast cancer (TNBC) is an aggressive neoplasia with no effective therapy. Our laboratory has developed a unique TNBC cell model presenting epithelial mesenchymal transition (EMT) a process known to be important for tumor progression and metastasis. There is increasing evidence showing that epigenetic mechanisms are involved in the activation of EMT. The objective of this study is to epigenetically reverse the process of EMT in TNBC by using DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi).

Methods

We evaluated the antitumor effect of three DNMTi and six HDACi using our TNBC cell model by MTT assay, migration and invasion assay, three dimensional culture, and colony formation assay. We then performed the combined treatment both in vitro and in vivo using the most potent DNMTi and HDACi, and tested the combined treatment in a panel of breast cancer cell lines. We investigated changes of EMT markers and potential signaling pathways associated with the antitumor effects.

Results

We showed that DNMTi and HDACi can reprogram highly aggressive TNBC cells that have undergone EMT to a less aggressive phenotype. SGI-110 and MS275 are superior to other seven compounds being tested. The combination of SGI with MS275 exerts a greater effect than single agent alone in inhibiting cell proliferation, motility, colony formation, and stemness of cancer cells. We also demonstrated that MS275 and the combination of SGI with MS275 exert in vivo antitumor effect. We revealed that the combined treatment synergistically reverses EMT through inhibiting EpCAM cleavage and WNT signaling, suppressing mutant p53, ZEB1, and EZH2, and inducing E-cadherin, apoptosis, as well as histone H3 tri-methylation.

Conclusions

Our study showed that DNMTi and HDACi exert antitumor activity in TNBC cells partially by epigenetically reprograming EMT. Our findings strongly suggest that TNBC is sensitive to epigenetic therapies. Therefore, we propose a new strategy to treat TNBC by using the combination of SGI-110 with MS275, which exerts superior antitumor effects by simultaneously targeting multiple pathways.

     

The histone deacetylase inhibitor trichostatin A alters microRNA expression profiles in apoptosis-resistant breast cancer cells

The development of drug resistance represents a major complication in the effective treatment of breast cancer. Epigenetic therapy, through the use of histone deacetylase inhibitors (HDACi) or demethylation agents, is an emerging area of therapeutic targeting in a number of ontological entities, particularly in the setting of aggressive therapy-resistant disease. Using the well-described HDAC inhibitor trichostatin?A (TSA) we demonstrate the suppression of in?vitro clonogenicity in the previously described apoptosis-resistant MCF-7TN-R breast carcinoma cell line. Additionally, recent work has demonstrated that these agents can alter the expression profile of microRNA signatures in malignant cells. Using an unbiased microRNA microarray analysis, changes in miRNA expression of MCF-7TN-R cells treated with TSA for 24?h were analyzed. We observed significant up-regulation of 22 miRNAs and down-regulation of 10 miRNAs in response to TSA treatment. Our results demonstrate that the HDACi, TSA, exerts anticancer activity in the apoptosis-resistant MCF-7TN-R breast carcinoma cell line. This activity is correlated with TSA alteration of microRNA expression profiles indicative of a less aggressive phenotype.     

Troglitazone inhibits histone deacetylase activity in breast cancer cells

We previously demonstrated that the PPARγ agonist Troglitazone (TRG), a potent antiproliferative agent, in combination with the anthracycline antibiotic Doxorubicin (DOX), is an effective killer of multiple drug resistant (MDR) human cancer cells. Cell killing was accompanied by increased global histone H3 acetylation. Presently, we investigated the epigenetic and cell killing effects of TRG in estrogen receptor (ER) positive MCF7 breast cancer cells. MCF7 cells were treated with the Thiazolidinediones (TZDs) TRG and Ciglitazone (CIG), the non-TZD PPARγ agonist 15PGJ2, and the histone deacetylase inhibitors (HDACi’s) Trichostatin A (TSA), sodium butyrate and PXD101. Using MTT cell viability assays, Western analyzes and mass spectrometry, we showed a dose-dependent increase in cell killing in TRG and HDACi treated cells, that was associated with increased H3 lysine 9 (H3K9) and H3K23 acetylation, H2AX and H3S10 phosphorylation, and H3K79 mono- and di-methylation. These effects were mediated through an ER independent pathway. Using HDAC activity assays, TRG inhibited HDAC activity in cells and in cell lysates, similar to that observed with TSA. Furthermore, TRG and TSA induced a slower migrating HDAC1 species that was refractory to HDAC2 associations. Lastly, TRG and the HDACi’s decreased total and phosphorylated AKT levels. These findings suggest that TRG’s mode of killing may involve downregulation of PI3K signaling through HDAC inhibition, leading to increased global histone post-translational modifications.     

Modulation of sensitivity to doxorubicin by the histone deacetylase inhibitor sodium butyrate in breast cancer cells

The histone deacetylase inhibitor sodium butyrate induces several gene products that modify cellular metabolism. Here, we investigated its ability to modulate glutathione-related detoxification enzymes in the breast cancer cell line MCF-7 and a derivative resistant to vincristine (VCREMS). We found that sodium butyrate induced glutathione S-transferase and glutathione-dependent peroxidase activities and triggered glutathione depletion. Expression of MRP1, an ATP-dependent GS-X pump, was unmodified. Moreover, isobologram analysis showed that sodium butyrate sensitized VCREMS to doxorubicin-mediated toxicity. Verapamil, an inhibitor of MRP1, did not significantly affect this chemosensitizing effect, suggesting that the observed toxicity stems from multifactorial mechanisms. Interestingly, synergism between sodium butyrate and doxorubicin was more pronounced in resistant VCREMS cells than in parental sensitive MCF-7 cells.     

组蛋白去乙酰化酶抑制剂MS-275在体外抑制胃癌细胞的实验研究

背景与目的:组蛋白去乙酰化酶抑制剂(histone deacetylase inhibitors,HDACis)对于很多肿瘤细胞具有选择性的诱导凋亡及分化作用,而对正常细胞的细胞毒性作用很低,这一选择性杀伤作用使HDACis成为目前抗肿瘤分子靶向药物的研究热点.本文研究了HDACis MS-275对人胃癌细胞SGC-7901、人胃黏膜正常细胞GES-1和张氏肝细胞(CHANG-LIVER)的选择性作用及机制,为HDACis的临床应用提供了理论依据.方法:不同终浓度MS-275处理SGC-7901细胞、GES-1和张氏肝细胞,用WST-1方法检测药物对细胞的生长抑制作用;AnnexinV、PI双标流式细胞术检测MS-275对肿瘤细胞SGC-7901和正常细胞的选择性杀伤作用;TUNEL染色观察肿瘤细胞核内凋亡情况.结果:MS-275对胃癌细胞SGC-7901具有明显的生长抑制作用,并且这种作用具有时间及剂量依赖性;MS-275的杀伤作用具有选择性,对正常细胞GES-1和张氏肝细胞并不表现出促凋亡作用;TUNEL染色证明MS-275能诱导SGC-7901细胞核内发生DNA断裂,是细胞发生凋亡的重要指标.结论:MS-275具有体外选择性杀伤胃癌细胞的作用,对正常细胞没有明显的杀伤作用,有希望成为新一代的胃癌临床治疗的肿瘤分子靶向药物.     

三阴性乳腺癌的治疗

三阴性乳腺癌（TNBC）是具有特殊侵袭性生物学行为及临床病理特征的一个乳腺癌亚型,其治疗一直是乳腺癌中的难点和热点问题。目前,手术和辅助放疗仍是早期TNBC局部治疗的主要方式,传统化疗、靶向治疗研究在TNBC的全身治疗中取得了一定的进展,同时,近几年新药物也不断涌现出来。