Effect of trichostatin A on lipopolysaccharide-induced injury and apoptosis of human microvascular endothelial cell / 中国小儿急救医学

Objective:To investigate the effect of histone deacetylase inhibitor trichostatin A(TSA) on the lipopolysaccharide(LPS)-induced injury and apoptosis of human microvascular endothelial cell(HMEC).Methods:HMECs were used as research cells to establish LPS-induced septic cell model, which were divided into three groups according to different treatments: control group (150 μL of phosphate buffer), LPS group (150 μL of 5 μg/mL LPS), LPS+ TSA group (150 μL of 5 μg/mL LPS and 500 μg/L TSA). After cells of each group were cultured for 24 h and 48 h, the concentration of lactate dehydrogenase(LDH)in the culture supernatant was detected by enzyme-linked immunosorbent assay and the apoptosis rate of HMECs was detected by Annexin V-FTTC/PI staining, then comparison between different groups were made.Results:Compared with the control group, LDH concentration in LPS group increased significantly at 24 h[(4.67±1.27) ng/L vs. (11.57±0.83) ng/L ] and 48 h[(7.93±0.80) ng/L vs. (12.72±0.89) ng/L ]; Compared with LPS group, LDH concentration in LPS + TSA group decreased significantly at 24 h[(6.01±0.29) ng/L ] and 48 h[(5.96±0.27) ng/L ], and the differences were statistically significant ( P<0.05). Compared with the control group, the apoptosis rates of HMEC cells in LPS group were significantly higher at 24 h[(0.92±0.89)% vs. (1.66±0.09)% ] and 48 h[(1.09±0.14)% vs. (5.01±0.16)%]; Compared with LPS group, the apoptosis rate of HMEC cells in LPS + TSA group significantly decreased at 24 h[(1.36±0.01)% ] and 48 h[(4.19±0.23)% ], the differences were statistically significant ( P<0.05). Conclusion:TSA has the protective effect of reducing cell injury and apoptosis in sepsis.

Entinostat, a class I selective histone deacetylase inhibitor, plus exemestane for Chinese patients with hormone receptor-positive advanced breast cancer: A multicenter, randomized, double-blind, placebo-controlled, phase 3 trial

Entinostat plus exemestane in hormone receptor-positive (HR+) advanced breast cancer (ABC) previously showed encouraging outcomes. This multicenter phase 3 trial evaluated the efficacy and safety of entinostat plus exemestane in Chinese patients with HR + ABC that relapsed/progressed after ≥1 endocrine therapy. Patients were randomized (2:1) to oral exemestane 25 mg/day plus entinostat (n = 235) or placebo (n = 119) 5 mg/week in 28-day cycles. The primary endpoint was the independent radiographic committee (IRC)-assessed progression-free survival (PFS). The median age was 52 (range, 28-75) years and 222 (62.7%) patients were postmenopausal. CDK4/6 inhibitors and fulvestrant were previously used in 23 (6.5%) and 92 (26.0%) patients, respectively. The baseline characteristics were comparable between the entinostat and placebo groups. The median PFS was 6.32 (95% CI, 5.30-9.11) and 3.72 (95% CI, 1.91-5.49) months in the entinostat and placebo groups (HR, 0.76; 95% CI, 0.58-0.98; P = 0.046), respectively. Grade ≥3 adverse events (AEs) occurred in 154 (65.5%) patients in the entinostat group versus 23 (19.3%) in the placebo group, and the most common grade ≥3 treatment-related AEs were neutropenia [103 (43.8%)], thrombocytopenia [20 (8.5%)], and leucopenia [15 (6.4%)]. Entinostat plus exemestane significantly improved PFS compared with exemestane, with generally manageable toxicities in HR + ABC (ClinicalTrials.gov #NCT03538171).

Histone deacetylase (HDAC) inhibitors- based drugs are effective to control Mycobacterium tuberculosis infection and promote the sensibility for rifampicin in MDR strain

BACKGROUND Tuberculosis (TB) is a major public health problem, which has been aggravated by the alarming growth of drug-resistant tuberculosis. Therefore, the development of a safer and more effective treatment is needed. OBJECTIVES The aim of this work was repositioning and evaluate histone deacetylases (HDAC) inhibitors- based drugs with potential antimycobacterial activity. METHODS Using an in silico pharmacological repositioning strategy, three molecules that bind to the catalytic site of histone deacetylase were selected. Pneumocytes type II and macrophages were infected with Mycobacterium tuberculosis and treated with pre-selected HDAC inhibitors (HDACi). Subsequently, the ability of each of these molecules to directly promote the elimination of M. tuberculosis was evaluated by colony-forming unit (CFU)/mL. We assessed the expression of antimicrobial peptides and respiratory burst using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) FINDINGS Aminoacetanilide (ACE), N-Boc-1,2-phenylenediamine (N-BOC), 1,3-Diphenylurea (DFU), reduce bacillary loads in macrophages and increase the production of β-defensin-2, LL-37, superoxide dismutase (SOD) 3 and inducible nitric oxide synthase (iNOS). While only the use of ACE in type II pneumocytes decreases the bacterial load through increasing LL-37 expression. Furthermore, the use of ACE and rifampicin inhibited the survival of intracellular multi-drug resistance M. tuberculosis. MAIN CONCLUSIONS Our data support the usefulness of in silico approaches for drug repositioning to provide a potential adjunctive therapy for TB.

Protective effects of valproic acid on cardiac and cerebral injury in rats subjected to severe scalding combined with seawater immersion injury with delayed fluid replacement / 中国药房

OBJECTIVE To study the protective effects o f valproic acid on cardiac and cerebral injury in rats subjected to severe scalding combined with seawater immersion injury with delayed fluid replacement. METHODS The rats were divided into scalding+delayed fluid replacement group （group S ），scalding+seawater immersion+delayed fluid replacement group （group SS ）， scalding+seawater immersion+valproic acid+delayed fluid replacement group （group SSV ）according to random number table ，with 60 rats in each group. All groups were subjected to 35％total body surface area third-degree full-thickness scalding with boiled water. Group SS and group SSV were immersed in artificial ；seawater（30 min）immediately after scalding ，and group SSV was subcutaneously injected with valproic acid 300 mg/kg immediately after out of water. Sodium lactate Ringer ’s 0314-2279277。E-mail：125467374@qq.com injection was injected intravenously within 30 minutes according to 1/2 Parkland formula at 2 h after scalding in each group for delayed fluid replacement. The death time of rats was recorded ，and the average survival time and 24 h survival rate of rats in each group were calculat ed. Mean arterial pressure （MAP），heart rate （HR），respiration rate （RR），rectal temperature （RT），arterial blood pH ，arterial partial pressure of oxygen （PaO2），arterial blood partial pressure of carbon dioxide （PaCO2），HCO3－，creatine kinase MB isoenzyme （CK-MB）and neuron specific enolase （NSE）were detected before scalding ，at 0，2，5 h after scalding. The pathological changes of cardiac and cerebral tissue were observed. RESULTS The 24 h survival rate of group SS （55％）was significantly lower than that of group S （90％）， while that of group SSV （75％）was increased significantly ，compared with group SS （P＜0.05）. Compared with group S ，the levels of MAP ，RT，HR，pH，PaO2 and HCO 3－ in group SS were significantly lowered ，while the levels of CK-MB and NSE were increased significantly at 0，2，5 h after scalding ；the levels of PaCO 2 were increased significantly at 2，5 h after scalding ， while the levels of RR were decreased significantly at 0，2 h after scalding （P＜0.05）. Compared with group SS ，the levels of MAP，RT，HR，pH，PaO2 and HCO 3－ in group SSV were significantly increased ，while the levels of PaCO 2，CK-MB and NSE were decreased significantly at 2，5 h after scalding ；the level of RR was increased significantly at 2 h after scalding （P＜0.05）. At 2，5 h after scalding ，cardiac and cerebral injury of rats in group SS were aggravated significantly than that in group S ；cardiac and cerebral injury of rats in group SSV were relieved significantly than that in group SS. CONCLUSIONS After severe scalding combined seawater immersion injury ，hypodermic injection of sodium valproate could protect cardiac and cerebral function of rats ， improve vital signs and blood gas index ，prolong survival time and improve survival rate in rats.

Histone Deacetylase Inhibitors in the in Vitro Expansion of Hematopoietic Stem Cells / 中国医学科学院学报

The self-renewal and differentiation of hematopoietic stem cells(HSCs)are highly regulated by epigenetic modification,in which histone acetylation can activate or silence gene transcription.Histone deacetylase inhibitors(HDACIs)can inhibit the activity of histone deacetylase in HSCs to increase histone acetylation.A variety of HDACIs,such as trichostatin A and valproic acid,are used to expand HSCs in vitro,especially cord blood HSCs,combined with cytokines in serum-free culture to obtain more long-term repopulating cells.HDACIs promote the transcription of pluripotent genes related to stem cell self-renewal and inhibit the expression of genes related to differentiation,so as to promote the expansion and inhibit differentiation of HSCs.The expansion of cord blood HSCs by small molecular HDACIs in vitro is expected to improve the quantity of cord blood HSCs.The further research will focus on high-throughput screening for the most powerful HDACIs and the highly selective HDACIs,exploring the combination of epigenetic modifiers of different pathways.

Planejamento, síntese, modelagem molecular e avaliação biológica de novos potenciais inibidores duais HDAC/ MMP não-hidroxamatos / Design, synthesis, molecular modeling and biological evaluation of novel potential non-hydroxamate dual HDAC/ MMP inhibitors

A inibição de alvos específicos como metaloproteinase de matriz (MMP) e histona desacetilase (HDAC) é amplamente estudada para impedir o progresso do câncer. Foi estabelecido que a inibição concomitante de MMP e HDAC é eficaz no combate de tumores sólidos e hematológicos. Ambos os alvos possuem um íon Zn2+ em seu sítio ativo, fundamental para a atividade destas enzimas. A alta afinidade dos inibidores conhecidos de MMP e de HDAC é conferida, principalmente, por um potente grupo ligante de zinco (ZBG). O ácido hidroxâmico é o ZBG mais potente conhecido atualmente, entretanto, este apresenta instabilidade farmacocinética, levando a ineficácia e genotoxicidade em testes clínicos. Frente a este contexto, o presente trabalho teve como objetivo o planejamento, síntese, modelagem molecular e avaliação biológica de novos inibidores duais MMP/HDAC não-hidroxamatos. Os compostos foram planejados utilizando estratégias de hibridação molecular, a partir de arcabouços provenientes inibidores de HDAC e MMP, gerando compostos arilsulfonamídicos com variações no tipo de ZBG inserido e na sua respectiva posição relativa na estrutura geral. Foram sintetizados sete análogos, em duas a três etapas reacionais, utilizando métodos de sulfonilação e acoplamento com agentes condensantes, partindo dos ésteres para e meta aminobenzoicos. Os rendimentos globais variaram de 25% a 55% e os produtos obtidos foram caracterizados por RMN 1H e 13C, LC/MS, CLAE e ponto de fusão. Os compostos tiveram sua atividade citotóxica avaliada em células HOG (oligodendroma) e T98G (glioblastoma), dentre os quais o 6a, que possui o ZBG 2-amino anilida, foi o mais promissor, apresentando atividade nas duas linhagens na casa de nM. Ensaios de coordenação com Fe2+ comprovaram a capacidade quelante dos análogos contendo ácido hidroxâmico e dos demais compostos citotóxicos, 4a e 4b (ZBG-2, salicilal-hidrazona), o que não foi observado para o composto 6a. Os estudos de ancoramento molecular permitiram sugerir um modo de interação para todos os ZBG propostos frente aos respectivos alvos (HDAC e MMP), sendo observado que o ZBG 4 (2-amino anilida) faria a interação de modo monodentado com a HDAC, enquanto não seria possível o encaixe no sítio catalítico da MMP. Conclui-se, portanto, que o planejamento proposto permitiu a obtenção de compostos promissores como antitumorais, e que a substituição do ácido hidroxâmico por outros ZBG fornece moléculas ativas frente a células tumorais. Entretanto, a avaliação biológica frente à MMP e HDAC é necessária para confirmar o mecanismo de ação proposto

Inhibition of specific targets such as matrix metalloproteinase (MMP) and histone deacetylase (HDAC) is extensively studied regarding arrest cancer growth. Particularly, concomitant inhibition of MMP and HDAC is effective against solid and hematologic tumors. Both targets have an ion Zn2+ at their catalytic site, which is essential for respective enzymatic activity. High affinity of known MMP and HDAC inhibitors is mainly provided by a potent zinc binding group (ZBG). Hydroxamic acid is the most potent ZBG currently known; however, it presents low pharmacokinetics stability, which results in its ineffectiveness and genotoxicity along clinical trial. So, the aim of this work comprised the design, synthesis, molecular modeling and biological evaluation of novel potential non-hydroxamate dual HDAC/ MMP inhibitors. Compounds were designed by molecular hybridation, employing scaffolds from HDAC and MMP inhibitors, which provided arylsulfonamides with variation about the ZBG type and its respective relative position in the general structure. Seven compounds were synthesized, in two to three reaction steps, through methods that comprise sulfonilation and coupling with condensing agents, using para and meta-aminobenzoic esters as starting material. Compounds showed global yields around 25-55 % and were characterized by 1H and 13C NMR, LC/MS, HPLC and melting point. Compounds were evaluated about their cytotoxicity against HOG (oligodendroma) and T98G (glioblastoma) cells, which 6a, with ZBG 2-aminobenzamide, was the most promising molecules, presenting activity against both cell lines at nM range. Coordination assays with Fe2+ proved the chelating capacity of hydroxamate analogues as well as the cytotoxic compounds, 4a and 4b (ZBG-2, salicylal-hydrazone), which was not observed about 6a. Molecular docking allowed to suggest an interaction model for all proposed ZBG with the respective targets (MMP and HDAC), showing that (ZBG-4) 2-aminobenzamide interacts with HDAC by monodentate way, but does not docks at MMP catalytic site. We conclude that the proposed design allowed obtaining promising compounds as antitumors agents, and the replacement of hydroxamic acid by other ZBG provide active molecules against tumor cells. However, biological evaluation against MMP and HDAC is necessary to confirm the proposed action mechanism

Research progress in the molecular mechanisms of histone deacetylase inhibitors for radiosensitization / 中华放射医学与防护杂志

Radiotherapy is one of the most commonly used and effective method to treat malignant tumors in clinical practice. However, there are still some limitations including high radiotherapy doses, harmful side effects on normal tissues, and radiation resistance of tumor cells. Therefore, seeking safe and effective radiotherapy sensitizers to improve radiation sensitivity of tumor cells has been focused for a long time. Histone deacetylase inhibitors (HDACIs), as a kind of epigenetic modifiers, can regulate the sensitivity of tumor cells to ionizing radiation and ultraviolet radiation in addition to the inherent anticancer characteristics. This article reviewed the molecular mechanisms of HDACIs in enhancing radiation sensitivity and by selectively killing tumor cells.

Epigenetic therapies in patients with solid tumors: Focus on monotherapy with deoxyribonucleic acid methyltransferase inhibitors and histone deacetylase inhibitors

Epigenomics is the study of the gene expression changes due to epigenetic processes and not due to the deoxyribonucleic acid (DNA) base sequence alterations. The key mechanisms of epigenetic regulation include DNA methylation, histone modifications, and noncoding RNAs. Epigenetic alterations in cancer are predominantly linked with hypermethylation of promoters of the tumor suppressor genes, global DNA hypomethylation, and increased expression of histone deacetylases (HDAC). There is a growing need to investigate epigenetic patterns and to provide safe and effective, innovative therapeutic strategies for oncology patients, who did not improve on traditional anticancer regimens. The epi-drugs (e.g., DNA methyltransferase inhibitors, e.g., azacitidine and decitabine and HDAC inhibitors, e.g., vorinostat and romidepsin) have been approved for the clinical use. In this paper, we provide a brief overview of the mechanisms of action and targets for novel epi-drugs, focusing on their potential clinical applications in patients with solid tumors, resistant to standard oncology treatments

El ácido valproico como agente sensibilizador al tratamiento anticáncer / Valproic acid as a sensitizing agent in anticancer treatment

Resumen El ácido valproico es un fármaco antiepiléptico con más de 50 años de uso clínico. En la década pasada se descubrieron sus efectos anticancerígenos. El análisis de grupos de pacientes que utilizaron este fármaco durante años ha mostrado que disminuye la frecuencia de cáncer de cabeza y cuello. Estudios recientes evidencian el efecto anticáncer al combinar el ácido valproico con la quimioterapia, terapia biológica e inhibidores de sistemas antioxidantes, con resultados excepcionales. En esta revisión se analiza el metabolismo del ácido valproico y su aplicación contra el cáncer.

Abstract Valproic acid is an antiepileptic drug with more than 50 years of clinical use. In the past decade, its anticancer effects were discovered. Analyses in groups of patients who used this drug for years have shown that it decreases the frequency of head and neck cancer. Recent studies show the anticancer effect of combining valproic acid with chemotherapy, biological therapy and antioxidant systems inhibitors, with exceptional results. In this review, we analyze the metabolism of valproic acid and its application against cancer.

Effect of histone deacetylase and its inhibitor on tumor / 国际肿瘤学杂志

The occurrence and progress of tumor is the result of the interaction of heredity and epigenetics. Histone deacetylation modification,as an important epigenetic modification,plays an important role in tumorigenesis and development. The abnormal expression of histone deacetylase in normal tissues and cells promotes the development of tumor and is related to the proliferation and apoptosis,angiogenesis,metastasis and drug resistance of tumor cells,and becomes a new target of tumor therapy. Histone deacetylase inhibitors as anti-tumor drugs have a good prospect of application.

Role of Akt∕GSK-3β signaling pathway in trichostatin-A-induced reduction of cerebral ischemia-reperfusion injury in mice / 中华麻醉学杂志

Objective To evaluate the role of protein kinase B∕glycogen synthase kinase-3 beta (Akt∕GSK-3β) signaling pathway in trichostatin-A (TSA)-induced reduction of cerebral ischemia-reperfu-sion ( I∕R) injury in mice. Methods Forty pathogen-free healthy male Balb∕c mice, weighing 18-22 g, were divided into 4 groups ( n=10 each) using a random number table method: sham operation group ( S group), I∕R group, TSA group and TSA plus Akt inhibitor LY294002 group (TL group). Cerebral I∕R was induced by middle cerebral artery occlusion ( 1-h ischemia followed by 24-h reperfusion) . TSA 5 mg∕kg was intraperitoneally injected for 3 consecutive days before establishing the model in TSA group. TSA 5 mg∕kg was intraperitoneally injected for 3 consecutive days before establishing the model, and LY29400215 nmol∕kg was injected via the caudal vein at 30 min before establishing the model. Brain tissues were ob-tained at 24 h of reperfusion for determination of cerebral infarct size ( by TTC ) , activities of superoxidedismutase ( SOD) and reactive oxygen species ( ROS) and malondialdehyde ( MDA) content ( by colorimet-ric assay), cell apoptosis (by TUNEL) and expression of Akt, phosphorylated Akt (p-Akt), GSK-3βand phosphorylated GSK-3β ( p-GSK-3β) . The apoptosis index and ratios of p-Akt∕Akt and p-GSK-3β∕GSK-3β were calculated. Results Compared with S group, the cerebral infarct size was significantly in-creased, the activity of SOD in brain tissues was decreased, the MDA content and ROS activity in brain tissues and apoptosis index were increased, and the ratios of p-Akt∕Akt and p-GSK-3β∕GSK-3β were de-creased in I∕R group ( P<0. 05) . Compared with I∕R group, the cerebral infarct size was significantly de-creased, the activity of SOD in brain tissues was increased, the MDA content and ROS activity in brain tis-sues and apoptosis index were decreased, and the ratios of p-Akt∕Akt and p-GSK-3β∕GSK-3β were de-creased in TSA group ( P<0. 05) . Compared with TSA group, the cerebral infarct size was significantly in-creased, the activity of SOD in brain tissues was decreased, the MDA content and ROS activity in brain tissues and apoptosis index were increased, and the ratios of p-Akt∕Akt and p-GSK-3β∕GSK-3β were de-creased in TL group ( P<0. 05) . Conclusion The mechanism by which TSA attenuates cerebral I∕R injury is related to activating Akt∕GSK-3β signaling pathway in mice.

Anti-tumor effect of histone deacetylase inhibitors / 国际肿瘤学杂志

Histone deacetylase (HDAC) is a kind of protease,which plays an important role in the structural modification of chromosomes and the regulation of gene expression.Its excessive expression in cancer cells causes acetylation imbalance,which is closely related to the occurrence of tumor.The high efficiency and low toxicity of histone deacetylase inhibitor (HDACi) has been widely recognized as anti-tumor drug with the deepening of the study in epigenetics.It is expected to bring more breakthroughs in the treatment of tumor.

Histone deacetylase inhibitors:research advances / 国际药学研究杂志

Histone deacetylases(HDAC)and its inhibitors have been the hot spots in the field of cancer-treatment.At pres?ent,six HDAC inbibitors(HDACi)have been approved by FDA for the treatment of various hematological neoplasms and solid tu?mors.Besides,a number of new HDACi are undergoing clinical trials in different stages or preclinical experiments,which have shown great inhibitory activities.However,a series of side effects and dose-dependent problems have appeared due to the poor selectivity of inhibitors in HDAC subtypes.So a new HDACi with high-selectity to HDAC subtypes or drug-combination will be of importance to im?prove the therapeutic effect.This review highlights the structure modification in HDACi and multiple drugs combination to summarize the latest evolution of HDACi.

Progress of T-cell lymphoma treatment / 白血病·淋巴瘤

The 14th International Conference on Malignant Lymphoma (ICML) was held in Lugano, Switzerland from June 14, 2017 to June 17, 2017. More than 3500 lymphoma experts and scholars attended this unprecedented conference. In particular, the Joint Forum on Union for China Lymphoma Investigators (UCLI)-ICML jointly organised by UCLI and ICML had greatly improved Chinese academic status in the field of lymphoma worldwide. Chinese experience on the treatment of T-cell lymphoma was exchanged during the conference. This paper reviews the recent progress in treatment of T-cell lymphoma in the meeting.

Radiobiological effects of VPA-BSANPs on C6 and U87 glioma cells / 中华放射肿瘤学杂志

Objective To investigate the radiobiological effects of VPA-BSANPs on C6 and U87 glioma cells in vitro.Methods C6 and U87 glioma cells were treated with different concentrations of VPA and VPA-BSANPs for 12 h and 24 h,and MTT assay was used to determine cell viability.C6 and U87 cells were treated with different concentrations of VPA and VPA-BSANPs conbined with X-ray irradiation (0,2,4,6,and 8 Gy),and colony formation assay was used to determine plating efficiency (PE).C6 and U87 glioma cells were treated with different concentrations of VPA and VPA-BSANPs for 12 h,followed by X-ray irradiation (0,4,and 8 Gy),and flow cytometry using Annexin V-FITC/PI staining was used to examine cell apoptosis.Western blot was used to evaluate the effects of VPA and VPA-BSANPs on radiation-induced apoptosis protein expression.One-way ANOVA was used for comparison of means with homogeneity of variance between multiple groups,and the t-test was used for comparison of means between two groups.Results Without irradiation,VPA and VPA-BSANPs had no significant inhibitory effects on the proliferation of C6 and U87 cells (P=0.328,0.920).The PE of cells treated with VPA-BSANPs combined with irradiation was significantly lower than that of cells treated with VPA combined with irradiation (P=0.000).In C6 and U87 cells,VPA-BSANPs combined with irradiation increased the expression of p53 and Bax (P =0.000,0.000 and P =0.010,0.002),but reduced the expression of Bcl-2 (P =0.008,0.000).Active caspase-3 fragments were only found in the cells treated with VPA-BSANPs combined with irradiation and VPA combined with irradiation,but were less in the former cells than in the latter cells (P=0.004).The active fragments of peroxisome proliferator-activated receptor were only found in the cells treated with VPA-BSANPs combined with irradiation.Conclusions VPA-BSANPs can increase the radiosensitivity of C6 and U87 glioma cells in vitro,possibly by promoting the apoptosis of tumor cells induced by radiation.

Drug repurposing of histone deacetylase inhibitors that alleviate neutrophilic inflammation in acute lung injury and idiopathic pulmonary fibrosis via inhibiting leukotriene a4 hydrolase and blocking LTB4 biosynthesis / 中国药理学与毒理学杂志

OBJECTIVE Leukotriene B4 (LTB4) biosynthesis and subsequently neutrophilic inflam?mation may provide a potential strategy for the treatment of acute lung injury (ALI) or idiopathic pulmonary fibrosis (IPF). To provide a potential strategy for the treatment of ALI or IPF, we identified potent inhibi?tors of Leukotriene A4 hydrolase (LTA4H), a key enzyme in the biosynthesis of LTB4. METHODS In this study, we identified two known histone deacetylase (HDAC) inhibitors, suberanilohydroxamic acid (SAHA) and its analogue 4-(dimethylamino)-N-〔7-(hydroxyamino)-7-oxoheptyl〕benzamide (M344), as effective inhibitors of LTA4H using enzymatic assay, thermofluor assay, and X- ray crystallographic investigation. We next tested the effect of SAHA and M344 on endogenous LTB4 biosynthesis in neutrophils by ELISA and neutrophil migration by transwell migration assay. A murine experimental model of ALI was induced by lipopolysaccharide(LPS) inhalation. Histopathological analysis of lung tissue using H&E staining revealed the serious pulmonary damage caused by LPS treatment and the effect of the SAHA. We next examined mRNA and protein levels of pro-inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid using qRT- PCR and ELISA to further investigate the underlying mechanisms of anti-inflammatory activities by SAHA. We also investigated the effects of SAHA and M344 on a murine experimental model of bleomycin (BLM)-induced IPF model. RESULTS The results of enzymatic assay and X-ray crystallography showed that both SAHA and M344 bind to LTA4H, signif?icantly decrease LTB4 levels in neutrophil, and markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose. CONCLUSION Collectively, SAHA and M344 would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis.

Effects of Histone Deacetylase Inhibitor (Valproic Acid) on the Expression of Hypoxia-inducible Factor-1 Alpha in Human Retinal Müller Cells

PURPOSE: To evaluate the effects of valproic acid (VPA), a histone deacetylase inhibitor (HDACI), on the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) in human retinal Müller cells under hypoxic conditions. METHODS: Chemical hypoxia was induced in human retinal Müller cells (MIO-M1) by treatment with increasing concentrations of cobalt(II) chloride (CoCl₂). Müller cells were also treated with a set concentration of CoCl₂, along with various concentrations of VPA. The expression of HIF-1α and VEGF in the treated Müller cells was determined by enzyme-linked immunosorbent assay. RESULTS: Exposure of human retinal Müller cells to increasing concentrations of CoCl₂ produced a dose-dependent increase in HIF-1α expression. The addition of increasing concentrations of VPA lead to a dose-dependent decrease in expression of HIF-1α and VEGF in Müller cells exposed to a set concentration of CoCl₂. CONCLUSIONS: HDACI VPA downregulated the expressions of HIF-1α and VEGF in human retinal Müller cells under hypoxic conditions. Using HDACI to target HIF-1α expression in Müller cells could be a new therapeutic strategy for the treatment of retinal vascular diseases.

Induction of Apoptosis in Intestinal Toxicity to a Histone Deacetylase Inhibitor in a Phase I Study with Pelvic Radiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: When integrating molecularly targeted compounds in radiotherapy, synergistic effects of the systemic agent and radiation may extend the limits of patient tolerance, increasing the demand for understanding the pathophysiological mechanisms of treatment toxicity. In this Pelvic Radiation and Vorinostat (PRAVO) study, we investigated mechanisms of adverse effects in response to the histone deacetylase (HDAC) inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) when administered as a potential radiosensitiser. MATERIALS AND METHODS: This phase I study for advanced gastrointestinal carcinoma was conducted in sequential patient cohorts exposed to escalating doses of vorinostat combined with standard-fractionated palliative radiotherapy to pelvic target volumes. Gene expression microarray analysis of the study patient peripheral blood mononuclear cells (PBMC) was followed by functional validation in cultured cell lines and mice treated with SAHA. RESULTS: PBMC transcriptional responses to vorinostat, including induction of apoptosis, were confined to the patient cohort reporting dose-limiting intestinal toxicities. At relevant SAHA concentrations, apoptotic features (annexin V staining and caspase 3/7 activation, but not poly-(ADP-ribose)-polymerase cleavage) were observed in cultured intestinal epithelial cells. Moreover, SAHA-treated mice displayed significant weight loss. CONCLUSION: The PRAVO study design implemented a strategy to explore treatment toxicity caused by an HDAC inhibitor when combined with radiotherapy and enabled the identification of apoptosis as a potential mechanism responsible for the dose-limiting effects of vorinostat. To the best of our knowledge, this is the first report deciphering mechanisms of normal tissue adverse effects in response to an HDAC inhibitor within a combined-modality treatment regimen.

Epigenetic Modifications: Novel Therapeutic Approach for Thyroid Cancer

The incidence of thyroid cancer is growing the fastest among all cancers in the United States, especially in women. The number of patients with thyroid neoplasm is part of an even larger number of patients who often need to undergo an operation to exclude a cancer diagnosis. While differentiated thyroid cancer (papillary thyroid cancer and follicular thyroid cancer) accounts for most cases of thyroid cancer and has a relatively good prognosis, effective treatments for patients with de-differentiated and anaplastic thyroid cancer are still gravely needed. Despite progress in the identification of genetic changes in thyroid cancer, the impact of aberrant epigenetic alterations on thyroid cancer remains to be fully elucidated. Understanding of the roles of epigenetic changes in thyroid cancer could open new opportunities for the identification of innovative molecular targets for novel treatment modalities, especially for anaplastic thyroid cancer for which treatment is very limited. This article briefly reviews the studies that exemplify the potential for and promise of using epigenetic regulators in the treatment of thyroid cancer.

Protective effect of histone deacetylase inhibitor MS-275 on acute liver failure induced by D-galactosamine and lipopolysaccharide in mice / 中华临床感染病杂志

Objective To investigate the effect of MS-275, an histone deacetylase ( HDAC ) inhibitor, on acute liver failure ( ALF ) induced by D-galactosamine and lipopolysaccharide in mice. Methods Thirty specific pathogen free (SPF) C57BL/6 male mice were randomly and equally divided into control, ALF model and MS-275 groups. ALF model was induced by D-galactosamine ( D-Gal ) and lipopolysaccharide (LPS), and the mice in MS-275 group received MS-275 (1 mg/kg) at 2 h before the induction of ALF.Serum and liver samples of mice were obtained at 24 h after ALF induction.The serum levels of ALT, AST, TBil and tumor necrosis factor-alpha ( TNF-α) , interferon γ( IFNγ) , interleukin ( IL )-1β, high mobility group box 1 ( HMGB1 ) were tested by biochemical methods or ELISA kit, respectively.The expression of HDAC1, HDAC3, acetylation of histone H3, H4, P65, acetylation and phosphorylation of P65 in liver were detected by Western blotting.The changes of histology in liver was detected by HE staining, and the translocation of P65 in liver was detected by immunohistochemistry. Comparison of variables among the groups was performed using t test.Results MS-275 inhibited the infiltration of inflammatory cells and improved the pathological changes of liver tissue.Compared with ALF group, serum ALT, AST, TBil levels were decreased in MS-275 group ( t =-22.215, -11.914 and-12.160, all P<0.05), but still higher than those in the control group (t=14.852, 11.692 and 8.333, all P<0.05); serum TNF-α, IFNγ, IL-1β, HMGB1 levels were also significantly decreased in MS-275 group (t=-7.926, -3.427, -2.475 and -5.920, all P<0.05), but TNF-αand IFNγwere still higher than those in the control group (t=5.541 and 5.514, all P<0.05).Compared with control group, the expression of class I HDAC in liver tissue was significantly decreased in MS-275 group ( t=-3.676 and-10.576, P<0.05), while the expressions of acetylation of histone H3, H4 and P65 were significantly increased (t=3.976, 5.559 and 4.588, all P<0.05).MS-275 inhibited the translocation of P65 from cytoplasm to the nucleus.Conclusion MS-275 can protect liver from acute failure in mice through enhancing the acetylation levels of non-histones.