曲古抑菌素A对肾癌细胞系GRC-1生长的抑制作用

目的 研究组蛋白去乙酰化酶(HDAC)抑制药曲古抑菌素A(TSA)对肾癌GRC-1细胞生长的影响及其作用机制. 方法使用TSA处理GRC-1细胞. 噻唑蓝(MTT)法检测细胞生长;流式细胞仪分析细胞凋亡及细胞周期;Western blot免疫印迹分析p53,p21和bcl-2表达. 结果 TSA能明显抑制GRC-1细胞的增殖,且具有明显的剂量依赖性;TSA处理72 h的GRC-1细胞早期凋亡率明显提高,G0/G1期细胞比例显著升高,S期细胞比例显著降低. TSA能够明显下调bcl-2的表达,上调p21的表达,而对p53的没有显著影响. 结论TSA可以通过诱导肾肿瘤细胞的凋亡和周期阻滞而抑制癌细胞生长;其发生机制可能与下调抗凋亡基因bcl-2和上调肿瘤抑制基因p21的表达有关,TSA可能依赖非p53途径调控p21的表达.     

曲古霉素A对人子宫内膜癌HEC-1B细胞增殖和凋亡的作用及相关机制

【目的】探讨组蛋白去乙酰化酶抑制剂曲古霉素A(trichostatin A,TSA)对人子宫内膜癌HEC-1B细胞增殖和凋亡的作用及其可能机制。【方法】应用不同浓度的TSA处理子宫内膜癌HEC-1B细胞72 h,Western blotting法检测细胞内组蛋白H4乙酰化水平及p21蛋白,荧光定量PCR方法检测p21基因mRNA表达,MTT法检测细胞增殖,流式细胞术检测细胞凋亡率。【结果】经TSA作用后,人子宫内膜癌HEC-1B细胞内组蛋白H4乙酰化水平增加,p21基因mRNA及蛋白表达增加;同时细胞生长受到抑制,细胞凋亡增加。【结论】TSA通过提高组蛋白乙酰化水平,增加p21基因表达,抑制子宫内膜癌HEC-1B细胞的增殖和诱导细胞凋亡。     

The epigenetics of Alzheimer's disease--additional considerations

The critical commentaries following our review of the epigenetics of Alzheimer's disease (AD) amplify a number of key points with respect to the role of 1-carbon metabolism, the phenomenon of allele-specific methylation, the potentially critical explanatory link provided by epigenetic mechanisms for genome-wide association and large-scale gene expression array studies, and new therapeutic approaches afforded by epigenetic manipulation in Alzheimer's disease.     

MS-275体外诱导膀胱癌细胞凋亡的机制探讨

目的研究组蛋白去乙酰化酶(HDAC)抑制剂MS-275对膀胱癌T24细胞的诱导凋亡作用,并初步探讨其分子机制。方法用MTT法检测MS-275对T24细胞的生长抑制作用,并观察其有效作用浓度,采用荧光显微镜及原位末端标记(TUNEL)法观察和检测MS-275对T24细胞的诱导凋亡作用,采用流式细胞仪(FCM)检测Bcl-2和Bax在细胞内表达的动态变化。结果 MS-275抑制T24细胞的半抑制浓度(IC50)为(5.21±0.61)μmol/L。4.0μmol/L的MS-275处理T24细胞后可观察到典型的凋亡形态学变化,且随着作用时间的延长,细胞凋亡率逐渐升高,同时引起Bcl-2及Bax的表达率分别下调和上调。结论 HDAC抑制剂具有体外诱导膀胱癌细胞凋亡的作用,其作用机制涉及Bcl-2及Bax表达的动态改变。     

DNA甲基转移酶1和组蛋白去乙酰化酶1在子宫内膜异位症在位内膜的表达

目的 探讨DNA甲基转移酶1（DNMT1）和组蛋白去乙酰化酶1（HDAC1）在子宫内膜异位症患者子宫内膜中的表达及其两者在子宫内膜异位症发生、发展中的作用。方法 选取子宫内膜异位症患者在位内膜18例, 无子宫内膜异位症的对照子宫内膜20例,应用免疫组织化学法测定DNMT1的分布,应用免疫印迹法检测内膜组织中DNMT1和HDAC1蛋白的表达。结果 免疫组织化学提示,DNMT1主要分布于子宫内膜腺上皮细胞和间质细胞的胞核;子宫内膜异位症在位内膜中DNMT1的表达强度显著高于对照组子宫内膜（P<0.01）。免疫印迹发现,子宫内膜异位症在位内膜DNMT1和HDAC1蛋白的表达高于对照组子宫内膜, 差异有统计学意义（P<0.05）;且两者的表达呈正相关 （P<0.05）。结论 DNMT1和HDAC1在EMs患者的高表达可能在子宫内膜异位症的发生、发展中起着重要作用。     

Inhibition of histone deacetylase for the treatment of biliary tract cancer： A new effective pharmacological approach

AIM:TO investigate in vitro and in vivo therapeutic effects of histone deacetylase inhibitors NVP-LAQ824 and NVP-LBH589 on biliary tract cancer. METHODS:Cell growth inhibition by NVP-LAQ824 and NVP-LBH589 was studied in vitro in 7 human biliary tract cancer cell lines by MTT assay.In addition,the anti- tumoral effect of NVP-LBH589 was studied in a chimeric mouse model.Anti-tumoral drug mechanism was assessed by immunoblotting for acH4 and p21~(WAF-1/CIP-1), PARP assay,cell cycle analysis,TUNEL assay,and immunhistochemistry for MIB-1. RESULTS:In vitro treatment with both compounds significantly suppressed the growth of all cancer cell lines[mean IC_(50)(3 d)0.11 and 0.05μmol/L, respectively],and was associated with hyperacetylation of nucleosomal histone H4,increased expression of p21~(WAF-1/CIP-1),induction of apoptosis(PARP cleavage),and cell cycle arrest at G2/M checkpoint.After 28 d,NVP- LBH589 significantly reduced tumor mass by 66%(bile duct cancer)and 87%(gallbladder cancer)in vivo in comparison to placebo,and potentiated the efficacy of gemcitabine.Further analysis of the tumor specimens revealed increased apoptosis by TUNEL assay and reduced cell proliferation(MIB-1). CONCLUSION:Our findings suggest that NVP-LBH589 and NVP-LAQ824 are active against human biliary tract cancer in vitro.In addition,NVP-LBH589 demonstrated significant in vivo activity and potentiated the efficacy of gemcitabine.Therefore,further clinical evaluation of this new drug for the treatment of biliary tract cancer is recommended.     

Screening of amide analogues of Trichostatin A in cultures of primary rat hepatocytes: search for potent and safe HDAC inhibitors

Summary  The vast majority of preclinical studies of HDAC inhibitors (HDAC-I) focus on the drug–target (cancer) cell interaction, whereas little attention is paid to the effects on non-target healthy cells, which could provide decisive information to eliminate potential cytotoxic compounds at a very early stage during drug development. In the current study we used cultures of primary rat hepatocytes as a read out system to select for the most potent HDAC-I in the group of structural analogues of an archetypal HDAC-I, namely Trichostatin A. This kind of approach allowed selecting compounds with high biological activity and with no apparent toxicity towards cultured hepatocytes. Joanna Fraczek and Sarah Deleu contributed equally to this article. T. Vanhaecke is a postdoctoral research fellow of the Fund for Scientific Research Flanders (FWO-Vlaanderen, Belgium)