PIG7与丙戊酸促进人白血病细胞SKNO-1的分化和凋亡

 目的：研究p53诱导基因 7（PIG7）对人白血病细胞SKNO-1的作用及组蛋白脱乙酰酶抑制剂丙戊酸(VPA)的协同效应。方法：SKNO-1细胞经不同浓度的VPA（1~10 mmol/L）分别作用后,用MTT法检测VPA对SKNO-1细胞增殖的影响。通过病毒包装及感染系统分别将带有PIG7开放读码框和反义寡核苷酸片段的慢病毒载体导入SKNO-1细胞,用RT-PCR及Western blotting检测SKNO-1细胞中PIG7 的mRNA及蛋白表达情况;用流式细胞术检测VPA作用于病毒感染后SKNO-1细胞的凋亡率和分化抗原CD11b的表达; DNA ladder实验分析细胞的凋亡。结果：VPA可明显抑制SKNO-1细胞增殖,且具有时间、剂量依赖性。过表达PIG7促进SKNO-1细胞的凋亡和分化, 联合VPA作用后细胞分化抗原CD11b的表达水平和细胞凋亡率明显高于空载体组（P<0.05）,并出现典型的DNA梯状条带。结论：VPA具有抑制SKNO-1细胞增殖和诱导其分化及凋亡的作用。过表达PIG7可促进SKNO-1细胞的凋亡和分化,并增加SKNO-1细胞对VPA的敏感性。过表达PIG7联合VPA有望成为白血病治疗的新策略。     

Epigenetic regulation in antiviral innate immunity

Emerging life-threatening viruses have posed great challenges to public health. It is now increasingly clear that epigenetics plays a role in shaping host-virus interactions and there is a great need for a more thorough understanding of these intricate interactions through the epigenetic lens, which may represent potential therapeutic opportunities in the clinic. In this review, we highlight the current understanding of the roles of key epigenetic regulators — chromatin remodeling and histone modification — in modulating chromatin openness during host defense against virus. We also discuss how the RNA modification m6A (N6-methyladenosine) affects fundamental aspects of host-virus interactions. We conclude with future directions for uncovering more detailed functions that epigenetic regulation exerts on both host cells and viruses during infection.     

新型组蛋白去乙酰化酶抑制剂对缺氧损伤心肌细胞的保护作用研究

目的：利用化学发光方法和细胞筛选模型,检测新型组蛋白去乙酰化酶抑制剂（ histone deacetylase inhibitor, HDACi）JZ005的抑制组蛋白去乙酰化酶（histone deacetylases,HDACs）的活性;建立氯化钴损伤的心肌细胞缺氧模型,初步探讨JZ005对缺氧损伤细胞的保护作用。方法采用脂质体转染法将含有p21启动子元件的荧光素酶报告基因真核表达载体pCI-p21-Luc转入到人胚肾细胞293中,用G418筛选获得稳定转染荧光素酶报告基因的单克隆细胞系;采用已报道的HDACi曲古抑菌素A（ trichostatina A,TSA）为阳性对照,检测细胞筛选模型的稳定性;用HDACi化学发光检测试剂盒及上述细胞筛选模型测定JZ005抑制HDACs的活性;用不同浓度的JZ005处理氯化钴缺氧损伤的大鼠胚胎心肌细胞（H9c2）,MTT法检测JZ005对缺氧损伤细胞的保护作用。免疫印迹法检测JZ005处理后正常及缺氧损伤心肌细胞组蛋白H3的乙酰化水平变化。流式细胞术检测JZ005对H9c2细胞缺氧损伤后凋亡的影响。结果建立含p21启动子元件荧光素酶报告基因的HDACi细胞筛选模型;JZ005能够显著抑制HDACs的活性,浓度50～400μmol／L,抑制率＞50％。对缺氧损伤的心肌细胞具有明显保护作用,与对照组相比,细胞存活率提高38．33％、56．00％和35．20％,同时能够上调缺氧损伤心肌细胞组蛋白H3的乙酰化水平,拮抗缺氧损伤心肌细胞的凋亡,细胞凋亡数目从对照组的12．89％分别下降到给药组（25,50和100μmol／L）的6．63％、10．56％和8．89％。结论成功建立了HDACi的细胞筛选模型;JZ005作为一种新型的HDACi ,具有明显的保护心肌细胞拮抗缺氧损伤的作用,提示JZ005有可能开发成一种治疗缺氧损伤的药物。     

Epigenetics and pancreatic cancer:Pathophysiology and novel treatment aspects

An improvement in pancreatic cancer treatment represents an urgent medical goal.Late diagnosis and high intrinsic resistance to conventional chemotherapy has led to a dismal overall prognosis that has remained unchanged during the past decades.Increasing knowledge about the molecular pathogenesis of the disease has shown that genetic alterations,such as mutations of K-ras,and especially epigenetic dysregulation of tumor-associated genes,such as silencing of the tumor suppressor p16ink4a,are hallmarks of pancreatic cancer.Here,we describe genes that are commonly affected by epigenetic dysregulation in pancreatic cancer via DNA methylation,histone acetylation or miRNA(microRNA)expression,and review the implications on pancreatic cancer biology such as epithelial-mesenchymal transition,morphological pattern formation,or cancer stem cell regulation during carcinogenesis from PanIN(pancreatic intraepithelial lesions)to invasive cancer and resistance development.Epigenetic drugs,such as DNA methyltransferases or histone deactylase inhibitors,have shown promising preclinical results in pancreatic cancer and are currently in early phases of clinical development.Combinations of epigenetic drugs with established cytotoxic drugs or targeted therapies are promising approaches to improve the poor response and survival rate of pancreatic cancer patients.     

Histone Acetylation Level and Histone Acetyltransferase/Deacetylase Activity in Ejaculated Sperm from Normozoospermic Men

Purpose

The aim of this work was to evaluate nuclear histone acetylation level and total histone acetyltransferase (HAT) and deacetylase (HDAC) activity in ejaculated sperm and their relevance to conventional sperm parameters.

Materials and Methods

Thirty-three normozoospermic men were included in this study. Semen samples were processed by swim-up and then immunostained by six acetylation antibodies (H3K9ac, H3K14ac, H4K5ac, H4K8ac, H4K12ac, and H4K16ac). Our preliminary study verified the expression of HAT/HDAC1 in mature human sperm. From vitrified-warmed sperm samples, total HAT/HDAC activity was measured by commercially available kits. Nuclear DNA integrity was also measured by TUNEL assay.

Results

The levels of six acetylation marks were not related with conventional sperm parameters including sperm DNA fragmentation index (DFI) as well as HAT/HDAC activity. However, sperm DFI was positively correlated with HAT activity (r=0.038 after adjustment, p<0.02). HAT activity showed a negative relationship with HDAC activity (r=-0.51, p<0.01). Strict morphology was negatively correlated with acetylation enzyme index (=HAT activity/HDAC activity) (r=-0.53, p<0.01).

Conclusion

Our works demonstrated a significant relationship of acetylation-associated enzyme activity and strict morphology or sperm DFI.     

Design,synthesis, and biological evaluation of target water‐soluble hydroxamic acid‐based HDACi derivatives as prodrugs

Four compounds T1 , T2 , T3 , and T4 were designed and synthesized as Vorinostat and Belinostat derivatives being the target water‐soluble prodrugs. The water solubility of Vorinostat derivatives, T1 and T2 , exhibited 400‐ to 600‐fold higher than that of Vorinostat, and Belinostat derivatives, T3 and T4 , showed 600‐ to 750‐fold higher than that of Belinostat. Four compounds were evaluated for their inhibitory activities against tumor cell lines HT‐29 and Hut‐78 in the absence or presence of β‐D‐glucuronidase. The inhibitory effects of T1 and T2 were comparable to Vorinostat in the presence of β‐D‐glucuronidase, but were higher than 10 μM in the absence of β‐D‐glucuronidase. Therefore, T1 and T2 are promising candidates for in vivo investigations with high potential to be the target water‐soluble prodrugs. IC₅₀ values of Belinostat derivatives T3 and T4 were not affected by β‐D‐glucuronidase, but T3 and T4 had the excellent cell proliferation inhibition on Hut‐78.     

Inhibition of autophagy significantly enhances combination therapy with sorafenib and HDAC inhibitors for human hepatoma cells

AIM:To clarify whether histone deacetylase inhibitors histone deacetylase inhibitors(HDACIs)can sensitize hepatocellular carcinoma(HCC)cells to sorafenib treatment.METHODS:Bax,Bcl-2,ATG5-ATG12,p21,and p27protein levels in Hep3B,HepG2,and PLC/PRF/5 cells were examined by Western blot.CCK8 and a fluorometric caspase-3 assay were used to examine cellular viability and apoptosis levels.The effect of Beclin-1 on sensitization of HCC cells to sorafenib was examined by transfecting Beclin-1 siRNA into Hep3B,HepG2,and PLC/PRF/5 cells.RESULTS:Autophagy inhibition enhances the inhibitory effects of vorinostat and sorafenib alone or in combination on HCC cell growth.Vorinostat and sorafenib synergistically induced apoptosis and cell cycle alterations.Western blot data indicated that HDACIs and Beclin-1 knockdown increased the p53 acetylation level.The knockdown of Beclin-1 enhanced the synergistic effect of the combination of vorinostat with sorafenib.CONCLUSION:HDACIs can sensitize HCC cells to sorafenib treatment by regulating the acetylation level of Beclin-1.