Histone Deacetylase Inhibitor MS-275 Research Articles

UHRF1 downmodulation enhances antitumor effects of histone deacetylase inhibitors in retinoblastoma by augmenting oxidative stress-mediated apoptosis.

Identification of new genetic pathways or molecular targets that sensitize cancer cells to chemotherapeutic drugs may improve the efficacy of current chemotherapy. Here, we report that downmodulation of UHRF1 (ubiquitin‐like with PHD and RING finger domains 1) in retinoblastoma (RB) cells increases the sensitivity to histone deacetylase (HDAC) inhibitors, augmenting apoptotic cell death. We found that UHRF1 depletion downregulates two redox‐responsive genes GSTA4 (glutathione S‐transferase α4) and TXN2 (thioredoxin‐2) in RB cells, and increases the basal level of intracellular oxidative stress. Antioxidant treatment significantly reduced both basal and HDAC inhibitor‐induced DNA damage and apoptosis in UHRF1‐depleted cells. Knockdown of GSTA4 or TXN2 sensitized RB cells to HDAC inhibitors, demonstrating that GSTA4 and TXN2 play key roles in redox homeostasis in RB cells and the susceptibility to HDAC inhibitor treatment upon UHRF1 depletion. In human primary RB, GSTA4 and TXN2 proteins were found to be mostly elevated along with high UHRF1 expression. In addition to augmentation of apoptosis in UHRF1‐depleted RB cells, we also show that UHRF1 downmodulation derepresses the expression of photoreceptor‐specific genes in RB cells in cooperation with a HDAC inhibitor MS‐275 and promotes neuron‐like differentiation. However, further investigation revealed that the enhanced growth‐inhibitory effects of MS‐275 in UHRF1‐depleted cells were still mainly due to robust apoptosis induction rather than differentiation‐mediated growth arrest. Consistent with our findings, UHRF1 depletion in RB cells increased the therapeutic efficacy of MS‐275 in murine orthotopic xenografts. These results provide a novel basis for potential benefits of UHRF1 targeting for RB treatment.

Improved Preimplantation Development of Cloned Porcine Embryos through Supplementation of Histone Deacetylase Inhibitor MS-275

Improved Preimplantation Development of Cloned Porcine Embryos through Supplementation of Histone Deacetylase Inhibitor MS-275

Inflammation-mediated deacetylation of the ribonuclease 1 promoter via histone deacetylase 2 in endothelial cells.

Ribonuclease 1 (RNase1) is a circulating extracellular endonuclease that regulates the vascular homeostasis of extracellular RNA and acts as a vessel- and tissue-protective enzyme. Upon long-term inflammation, high amounts of proinflammatory cytokines affect endothelial cell (EC) function by down-regulation of RNase1. Here, we investigated the transcriptional regulation of RNase1 upon inflammation in HUVECs. TNF-α or IL-1β stimulation reduced the expression of RNase1 relative to the acetylation state of histone 3 at lysine 27 and histone 4 of the RNASE1 promoter. Inhibition of histone deacetylase (HDAC) 1, 2, and 3 by the specific class I HDAC inhibitor MS275 abolished the TNF-α- or IL-1β-mediated effect on the mRNA and chromatin levels of RNase1. Moreover, chromatin immunoprecipitation kinetics revealed that HDAC2 accumulates at the RNASE1 promoter upon TNF-α stimulation, indicating an essential role for HDAC2 in regulating RNase1 expression. Thus, proinflammatory stimulation induced recruitment of HDAC2 to attenuate histone acetylation at the RNASE1 promoter site. Consequently, treatment with HDAC inhibitors may provide a new therapeutic strategy to stabilize vascular homeostasis in the context of inflammation by preventing RNase1 down-regulation in ECs.-Bedenbender, K., Scheller, N., Fischer, S., Leiting, S., Preissner, K. T., Schmeck, B. T., Vollmeister, E. Inflammation-mediated deacetylation of the ribonuclease 1 promoter via histone deacetylase 2 in endothelial cells.

Research progress in the role of FBXW7 in drug resistance against non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors in the world. NSCLC shows serious effect on prognosis for drug resistance, and it is necessary to study the molecular mechanism for drug resistance in NSCLC. Ubiquitin-proteasome system (UPS) can regulate some important cellular processes by degrading short-term protein, and the abnormal expression is closely related to the occurrence, development and prognosis of tumor. The F-box family protein is an important component of the ubiquitin proteasome, such as cycle regulation, transcriptional regulation, signal transduction, apoptosis and differentiation. F-box and WD-40 domain protein 7 (FBXW7) is just the classic protein components among F-box family protein. Studies have shown that FBXW7 is related to drug resistance in NSCLC. The main mechanism is that FBXW7 mutation leads to drug resistance by reducing ubiquitination and degradation of its downstream proteins, including Snail protein, myeloid cell leukemia sequence 1 (MCL-1), mammalian target of rapamycin (mTOR), and coiled-coil-domain containing 6 (CCDC6). Rapamycin, histone deacetylase inhibitor MS-275, and rabdosia are effective in drug-resistant NSCLC patients with FBXW7 mutation.

Investigation into the use of histone deacetylase inhibitor MS-275 as a topical agent for the prevention and treatment of cutaneous squamous cell carcinoma in an SKH-1 hairless mouse model.

Cutaneous squamous cell carcinomas are a common form of highly mutated keratinocyte skin cancers that are of particular concern in immunocompromised patients. Here we report on the efficacy of topically applied MS-275, a clinically used histone deacetylase inhibitor, for the treatment and management of this disease. At 2 mg/kg, MS-275 significantly decreased tumor burden in an SKH-1 hairless mouse model of UVB radiation-induced skin carcinogenesis. MS-275 was cell permeable as a topical formulation and induced histone acetylation changes in mouse tumor tissue. MS-275 was also effective at inhibiting the proliferation of patient derived cutaneous squamous cell carcinoma lines and was particularly potent toward cells isolated from a regional metastasis on an immunocompromised individual. Our findings support the use of alternative routes of administration for histone deacetylase inhibitors in the treatment of high-risk squamous cell carcinoma which may ultimately lead to more precise delivery and reduced systemic toxicity.

MS-275 Chemical Analogues Promote Hemoglobin Production and Erythroid Differentiation of K562 Cells

β-Thalassemia (β-thal) is a hemoglobinopathy characterized by reduced or absent β-globin production. Pharmacological reactivation of the γ-globin gene for the production of fetal hemoglobin (Hb F) presents an attractive treatment strategy. In an effort to identify promising therapeutic agents, we evaluated 80 analogues of the histone deacetylase inhibitor MS-275, a known Hb F inducer. The chemical analogues were identified via molecular modeling and targeted chemical modifications. Nine novel agents exhibited significant hemoglobin (Hb)-inducing and erythroid differentiation activities in the human K562 erythroleukemia cell line. Five of them appeared to be stronger inducers than the lead compound, MS-275, demonstrating the effectiveness of our method.

Class I histone deacetylase inhibitor MS-275 attenuates vasoconstriction and inflammation in angiotensin II-induced hypertension

ObjectiveNon-selective histone deacetylase (HDAC) inhibitors are known to improve hypertension. Here, we investigated the therapeutic effect and regulatory mechanism of the class I HDAC selective inhibitors, MS-275 and RGFP966, in angiotensin (Ang) II-induced hypertensive mice.Methods and resultsMS-275 inhibited the activity of HDAC1, HDAC2, and HDAC3, while RGFP966 weakly inhibited that of HDAC3 in a cell-free system. MS-275 and RGFP966 treatment reduced systolic blood pressure and thickness of the aorta wall in Ang II-induced hypertensive mice. MS-275 treatment reduced aorta collagen deposition, as determined by Masson’s trichrome staining. MS-275 decreased the components of the renin angiotensin system and increased vascular relaxation of rat aortic rings via the nitric oxide (NO) pathway. NO levels reduced by Ang II were restored by MS-275 treatment in vascular smooth muscle cells (VSMCs). However, MS-275 dose (3 mg·kg-1·day-1) was not enough to induce NO production in vivo. In addition, MS-275 did not prevent endothelial nitric oxide synthase (eNOS) uncoupling in the aorta of Ang II-induced mice. Treatment with MS-275 failed to inhibit Ang II-induced expression of NADPH oxidase (Nox)1, Nox2, and p47phox. MS-275 treatment reduced proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and monocyte chemoattractant protein (MCP)-1, as well as adhesion molecules. Histological analysis showed that Ang II-induced macrophage infiltration was reduced by MS-275 and RGFP966 administration.ConclusionsOur results indicate that class I HDAC selective inhibitors may be good therapeutic agents for the treatment of hypertension through the regulation of vascular remodeling and vasoconstriction, as well as inflammation.

Nerve-mediated expression of histone deacetylases regulates limb regeneration in axolotls

Axolotls have amazing abilities to regenerate their lost limbs. Nerve and wound epidermis have great impacts on this regeneration. Histone deacetylases (HDACs) have been shown to play roles in the regeneration of amphibian tails and limbs. In this study, a bi-phasic up-regulation of HDAC1 was noted before early differentiation stage of axolotl limb regeneration. Limb regeneration was delayed in larvae incubated with an HDAC inhibitor MS-275. Local injection of MS-275 or TSA, another HDAC inhibitor, into amputation sites of the juveniles did not interfere with wound healing but more profoundly inhibited local HDAC activities and blastema formation/limb regeneration. Elevation of HDAC1 expression was more apparent in wound epidermis than in mesenchyme. Prior denervation prohibited this elevation and limb regeneration. Supplementation of nerve factors BMP7, FGF2, and FGF8 in the stump ends after amputation on denervated limbs not only enabled HDAC1 up-regulation but also led to more extent of limb regeneration. In conclusion, nerve-mediated HDAC1 expression is required for blastema formation and limb regeneration.

The pro-apoptotic Bcl-2 family member Harakiri (HRK) induces cell death in glioblastoma multiforme

Harakiri (HRK) is a BH3-only protein of the Bcl-2 family and regulates apoptosis by interfering with anti-apoptotic Bcl-2 and Bcl-xL proteins. While its function is mainly characterized in the nervous system, its role in tumors is ill-defined with few studies demonstrating HRK silencing in tumors. In this study, we investigated the role of HRK in the most aggressive primary brain tumor, glioblastoma multiforme (GBM). We showed that HRK is differentially expressed among established GBM cell lines and that HRK overexpression can induce apoptosis in GBM cells at different levels. This phenotype can be blocked by forced expression of Bcl-2 and Bcl-xL, suggesting the functional interaction of Bcl-2/Bcl-xL and HRK in tumor cells. Moreover, HRK overexpression cooperates with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a known tumor-specific pro-apoptotic agent. Besides, secondary agents that augment TRAIL response, such as the histone deacetylase inhibitor MS-275, significantly increases HRK expression. In addition, GBM cell response to TRAIL and MS-275 can be partly abolished by HRK silencing. Finally, we showed that HRK induction suppresses tumor growth in orthotopic GBM models in vivo, leading to increased survival. Taken together, our results suggest that HRK expression is associated with GBM cell apoptosis and increasing HRK activity in GBM tumors might offer new therapeutic approaches.

Tackling tumor heterogeneity and phenotypic plasticity in cancer precision medicine: our experience and a literature review.

The predominant cause of cancer mortality is metastasis. The major impediment to cancer cure is the intrinsic or acquired resistance to currently available therapies. Cancer is heterogeneous at the genetic, epigenetic, and metabolic levels. And, while a molecular-targeted drug may be pathway-precise, it can still fail to achieve wholesome cancer-precise toxicity. In the current review, we discuss the strategic differences between targeting the strengths of cancer cells in phenotypic plasticity and heterogeneity and targeting shared vulnerabilities of cancer cells such as the compromised integrity of membranous organelles. To better recapitulate subpopulations of cancer cells in different phenotypic and functional states, we developed a schematic combination of 2-dimensional culture (2D), 3-dimmensional culture in collagen I (3D), and mammosphere culture for stem cells (mammosphere), designated as Scheme 2D/3D/mammosphere. We investigated how the tumor suppressor maspin may limit carcinoma cell plasticity and affect their context-dependent response to drugs of different mechanisms including docetaxel, histone deacetylase (HDAC) inhibitor MS-275, and ionophore antibiotic salinomycin. We showed that tumor cell phenotypic plasticity is not an exclusive attribute to cancer stem cells. Nonetheless, three subpopulations of prostate cancer cells, enriched through Scheme 2D/3D/mammosphere, show qualitatively different drug responses. Interestingly, salinomycin was the only drug that effectively killed all three cancer cell subpopulations, irrespective of their capacity of stemness. Further, Scheme 2D/3D/mammosphere may be a useful model to accelerate the screening for curative cancer drugs while avoiding costly characterization of compounds that may have only selective toxicity to some, but not all, cancer cell subpopulations.

Sonoporation by microbubbles as gene therapy approach against liver cancer.

IntroductionAn innovative method, known as sonoporation, was used to induce the expression of silenced genes, such as (but not restricted to) TRAIL and p53, in liver cancer cells (HepG2). The principal aim of the present study was the re-activation of silenced apoptotic pathways in liver cancer models, by using diagnostic synovial microbubble as plasmid gene delivery tools in combination with epigenetic treatments.Material and methodsHepG2 cells were used as a liver cancer model. Microbubbles (Sonovue®) were chosen as gene deliver system in combination with the sonoporation approach. Plasmid pEGFP-TRAIL and pEGFP-p53 were selected and propagated in Escherichia coli grown in LB broth, in order to obtain the necessary amount.ResultsSonoporation was induced by using transducer (Sonitron 2000) and, among the several conditions tested, 3 MHz, 51% Duty Cycle, and 5 W/cm2, 30 s resulted as the best parameters. Data collected showed a dose dependent effect in terms of output energy. A transfection efficacy of 30 – 50% was achieved and recombinant gene expression induced apoptotic effects. In order to increase efficacy, we used the histone deacetylase inhibitor (HDACi, entinostat) MS-275, able to activate TRAIL and thus inducing a stronger pro-apoptotic effect in combination with TRAIL-gene re-expression.ConclusionFor the first time, it was shown the possibility to induce the exogenous expression of the pro-apoptotic gene TRAIL and p53 in a liver cancer HepG2 cells via a sonoporation procedure. The epigenetic treatment using HDACi was able to increase the pro-apoptotic effects of the gene therapy.

Role of class I histone deacetylase in myocardial ischemia-reperfusion injury in diabetic rats and the relationship with AMPK/mTOR signaling pathway

Objective To evaluate the role of class Ⅰ histone deacetylase (HDAC) in myocardial ischemia-reperfusion (I/R) injury in diabetic rats and the relationship with adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway. Methods SPF healthy adult male Sprague-Dawley rats, weighing 210-220 g, were used in this study.Type I diabetes mellitus was induced by single intraperitoneal injection of streptozotocin dissolved in citrate buffer 60 mg/kg, and 8 weeks later the rats with type I diabetes mellitus were used for experiment.Forty-eight diabetic rats were divided into 4 groups (n=12 each) by using a random number table method: sham operation group (group S), myocardial I/R group (group I/R), myocardial I/R plus class I HDAC inhibitor MS-275 group (group I/R+ MS) and myocardial I/R plus MS-275 plus AMPK inhibitor Compound C group (group I/R+ MS+ CC). Myocardial I/R was induced by ligation of the left anterior descending branch of the coronary artery for 45 min followed by 180 min of reperfusion in anesthetized rats.In group I/R+ MS, MS-275 10 mg/kg was intraperitoneally injected once a day for 7 consecutive days, and myocardial I/R was produced after the end of administration.AMPK inhibitor Compound C 0.5 mg/kg was intravenously injected at 30 min before ischemia in group I/R+ MS+ CC.Six rats were sacrificed at the end of reperfusion for determination of myocardial infarct size.Another 6 rats were selected at the end of reperfusion and sacrificed for determination of the level of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in serum (by enzyme-linked immunosorbent assay), expression of AMPK, phosphorylated AMPK (p-AMPK), mTOR, phosphorylated mTOR (p-mTOR), ubiquitin-binding protein P62 (P62), microtubule-associated protein 1 light chain 3 Ⅰ (LC3 Ⅰ) and LC3Ⅱ in myocardial tissues (by Western blot). The ratios of p-AMPK/AMPK, p-mTOR/mTOR and LC3Ⅱ/Ⅰ were calculated. Results Compared with group S, the myocardial infarct size and levels of serum CK-MB and LDH were significantly increased in I/R, I/R+ MS and I/R+ M+ CC groups, the ratios of p-AMPK/AMPK and LC3Ⅱ/Ⅰ were significantly increased, p-mTOR/mTOR ratio was decreased, and P62 expression was down-regulated in group I/R+ MS (P 0.05). Compared with group I/R, the myocardial infarct size and levels of serum CK-MB and LDH were significantly decreased, the ratios of p-AMPK/AMPK and LC3Ⅱ/Ⅰ were increased, p-mTOR/mTOR ratio was decreased, and P62 expression was down-regulated in group I/R+ MS (P 0.05). Compared with group I/R+ MS, the myocardial infarct size and levels of serum CK-MB and LDH were significantly increased, the ratios of p-AMPK/AMPK and LC3Ⅱ/Ⅰ were decreased, p-mTOR/mTOR ratio was increased, and P62 expression was up-regulated in group I/R+ M+ CC (P<0.05). Conclusion Class Ⅰ HDAC is involved in myocardial I/R injury through enhancing AMPK/mTOR signaling pathway-regulated level of autophagy in diabetic rats. Key words: Histone deacetylase; Autophagy; Diabetes mellitus; Myocardial reperfusion injury; Protein-serine-threonine kinases; Receptor-interacting protein serine-threonine kinases

Histone Deacetylase-6 Inhibition is Protective in Liver Ischemia-Reperfusion Injury and Acetaminophen Toxicity in a Murine Model

Introduction Ischemia/reperfusion injury (IRI) is a major source of morbidity in liver transplantation and other surgical scenarios. In liver transplantation, IRI contributes to poor outcomes and early graft loss. A better understanding of the mechanisms of hepatic IRI may facilitate the development of new strategies for prevention and treatment. Histone deacetylases (HDACs) regulate diverse cellular processes. In the kidney, class I HDAC inhibition provides protection after ischemia. We sought to delineate the role of HDAC inhibition in mitigating liver ischemia reperfusion injury and other forms of liver injury. Methods Male wild type C57BL/6 (WT) mice were treated with pan-HDAC inhibitor trichostain A (TSA), class I HDAC inhibitor MS-275, HDAC6 inhibitor Tubastatin-A (TubA), Hsp90 inhibitor (17AAG), or control vehicle (DMSO) at 16 and 1 hour pre-IRI. Whole-body tamoxifen-inducible HDAC-1, -2, -6, and -8 deficient and tamoxifen-treated WT male mice were also assessed. Mice were subjected to 70% liver ischemia for 60 minutes under strict temperature control. Histopathologic analysis was conducted at 24 hours post injury, and scored with the Suzuki Score for liver injury. In the acetaminophen (APAP) toxicity experiments, WT mice were treated with vehicle (Tween80, Peg500, and ddH20) or TubA at 16 hours and again just prior to administration of a sublethal dose of APAP (500mg/kg). In both experiments, AST and ALT levels were assessed 24 hours after injury. Results TSA- and TubA-treated mice developed significantly less hepatocellular injury after liver IRI than controls (Fig 1A). H1-/- mice developed significantly less injury after IRI compared to controls, but HDAC6 gene deletion did not mitigate IRI (Fig 1B). HDAC6 inhibition demonstrated decreased histologic liver injury (Figure 1C). TubA also mitigated APAP-induced hepatocellular injury (Fig 1D). Conclusion Pan-HDAC inhibition mitigates liver injury after IRI. Selective inhibition of HDAC1 via inducible gene deletion and pharmacologic inhibition of HDAC6 both replicate this protection. These findings are distinct from the pattern of HDAC involvement in renal IRI and suggest tissue-specific roles for HDACs in IRI response. Pharmacologic inhibition of HDAC6 also mitigated APAP-induced hepatocellular injury suggesting that the protective effects of TubA are not injury-type specific. Further experiments, including mechanistic studies, are required. NIH/NIDDK 1K08DK092282-01.

Palmitate and insulin counteract glucose-induced thioredoxin interacting protein (TXNIP) expression in insulin secreting cells via distinct mechanisms.

Glucose and palmitate synergistically stimulate insulin secretion, but chronically elevated they induce apoptotic β-cell death. The glucotoxic effect has been attributed, at least partly, to the upregulation of the oxidative stress marker thioredoxin interacting protein (TXNIP). Palmitate downregulates TXNIP expression, the functional significance of which is still under debate. This study examines the mechanism and consequence of palmitate-mediated TXNIP regulation in insulin secreting cells. Palmitate (600 μM) reduced TXNIP mRNA levels in isolated human and mouse islets independently of FFAR1/GPR40. Similar effects of palmitate were observed in INS-1E cells and mimicked by other long chain fatty acids. The lowering of TXNIP mRNA was significant already 1 h after addition of palmitate, persisted for 24 h and was directly translated to changes in TXNIP protein. The pharmacological inhibition of palmitate-induced phosphorylation of AMPK, ERK1/2, JNK and PKCα/β by BML-275, PD98059, SP600125 and Gö6976, respectively, did not abolish palmitate-mediated TXNIP downregulation. The effect of palmitate was superimposed by a time-dependent (8 h and 24 h) decline of TXNIP mRNA and protein. This decline correlated with accumulation of secreted insulin into the medium. Accordingly, exogenously added insulin reduced TXNIP mRNA and protein levels, an effect counteracted by the insulin/IGF-1 receptor antagonist linsitinib. The inhibition of PI3K and Akt/PKB increased TXNIP mRNA levels. The histone deacetylase (HDAC1/2/3) inhibitor MS-275 completely abrogated the time-dependent, insulin-mediated reduction of TXNIP, leaving the effect of palmitate unaltered. Acute stimulation of insulin secretion and chronic accentuation of cell death by palmitate occurred independently of TXNIP regulation. On the contrary, palmitate antagonized glucose-augmented ROS production. In conclusion, glucose-induced TXNIP expression is efficiently antagonized by two independent mechanisms, namely via an autocrine activation of insulin/IGF-1 receptors involving HDAC and by palmitate attenuating oxidative stress of β-cells.

Discovery of Novel Pazopanib-Based HDAC and VEGFR Dual Inhibitors Targeting Cancer Epigenetics and Angiogenesis Simultaneously.

Herein a novel series of pazopanib hybrids as polypharmacological antitumor agents were developed based on the crosstalk between histone deacetylases (HDACs) and vascular endothelial growth factor (VEGF) pathway. Among them, one ortho-aminoanilide 6d and one hydroxamic acid 13f exhibited considerable total HDACs and VEGFR-2 inhibitory activities. The HDAC inhibitory activities endowed 6d and 13f with potent antiproliferative activities, which was not observed in the approved VEGFR inhibitor pazopanib. Compounds 6d and 13f possessed comparable HDAC isoform selectivity profiles to the clinical class I HDAC inhibitor MS-275 and the approved pan-HDAC inhibitor SAHA, respectively. 6d and 13f also exhibited uncompromised multiple tyrosine kinases inhibitory activities relative to pazopanib. The intracellular dual inhibition to HDAC and VEGFR of 6d and 13f was validated by Western blot analysis. In both HUVECs tube formation assay and rat thoracic aorta rings assay, 6d and 13f showed comparable antiangiogenic potencies to pazopanib. What's more, 6d possessed desirable pharmacokinetic profiles with the oral bioavailability of 72% in SD rats and considerable in vivo antitumor efficacy in a human colorectal adenocarcinoma (HT-29) xenograft model.

The Nephroprotective Effect of MS-275 on Lipopolysaccharide (LPS)-Induced Acute Kidney Injury by Inhibiting Reactive Oxygen Species (ROS)-Oxidative Stress and Endoplasmic Reticulum Stress.

BackgroundHistone deacetylase (HDAC) inhibitors can attenuate acute kidney injury (AKI)-mediated damage and reduce fibrosis in kidney disease models. The aim of the present study was to investigate the effects of the HDAC inhibitor MS-275 on lipopolysaccharide (LPS)-induced AKI and the associated mechanisms.Material/MethodsA LPS-induced model in 6–8 weeks-old mice was established by intraperitoneal injection of LPS (10 mg/kg), with pre-treatment of MS-275 (2 mg/kg/day) administered intraperitoneally for five days. In addition, HK-2 cells were exposed to LPS (1 μg/mL) at 0.1 nM, 1 nM, 10 nM, and 100 nM. For our in vitro MS-275 study, detection programs included histology, biochemical, immunohistochemistry, mRNA and protein expression as well as apoptosis.ResultsMS-275 ameliorated renal damage, enhanced the survival rate of the LPS-induced sepsis model, decreased the expressions of TNF-α, IL-1β, IL-6, COX-2, and NF-κBp65 nucleus translocation, suppressed the HDAC activity which was enhanced in septic AKI mice, and enhanced the acetylation of histone H3 and H4. Reactive oxygen species (ROS) production was enhanced in the kidney of LPS mice compared to control mice, while MS-275 suppressed the production of ROS in kidney tissue. In the in vitro studies, MS-275 reduced the LPS-induced apoptosis of HK-2 cells, inhibited ROS and MDA production, increased the production GSH and SOD activity, decreased the expressions of CHOP, GRP78, caspase3, and capase12, which was related to endoplasmic reticulum stress in LPS stimulated HK-2 cells.ConclusionsMS-275 pre-treatment improved renal function and ameliorated histological alterations, inflammation, and ROS production in LPS-induced AKI mice and may act through inhibiting ROS-oxidative stress and endoplasmic reticulum stress.

Histone deacetylase inhibitor MS-275 restores social and synaptic function in a Shank3-deficient mouse model of autism.

Autism is a neurodevelopmental disorder characterized by social deficits and repetitive behaviors. Genetic screening has identified synaptic, transcriptional, and chromatin genes disrupted in autistic patients. Haploinsufficiency of Shank3, which encodes a scaffold protein at glutamatergic synapses, is causally linked to autism. Using a Shank3-deficient mouse model that exhibits prominent autism-like phenotypes, we have found that histone acetylation in the prefrontal cortex (PFC) is abnormally low, which can be reversed by MS-275 (also known as Entinostat, SNDX-275), a class I histone deacetylase (HDAC) inhibitor that is selectively potent in PFC. A brief (3-day) treatment with MS-275 (i.p.) led to the sustained (11 days) rescue of autistic social preference deficits in Shank3-deficient mice, without altering locomotion, motor coordination, anxiety, or the increased grooming. MS-275 treatment also rescued the diminished NMDAR surface expression and NMDAR function induced by Shank3 deficiency. Moreover, F-actin at synapses was restored and the transcription of actin regulators was elevated by MS-275 treatment of Shank3-deficient mice, which may contribute to the recovery of actin-based NMDAR synaptic delivery. Taken together, these results suggest that MS-275 treatment could normalize the aberrant epigenetic regulation of genes, leading to the amelioration of synaptic and social deficits associated with autism.

Abstract 5065: Harnessing epigenetic reprogramming by histone deacetylase inhibitor MS275 for pancreatic cancer therapy

Abstract Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 85% of pancreatic cancer and is one of the most lethal malignancies with limited therapeutic options. Chromatin-modulating small molecules, or epigenetic drugs, have the ability to reprogram cell fate and alter disease phenotypes. The potential of these drugs for PDAC therapy remains to be fully investigated. Screening a panel of epigenetic drugs identified MS275 (MS, also called entinostat), a histone deacetylase inhibitor, as capable of suppressing PDAC cell proliferation and inhibiting stromal fibrosis. Genome-wide expression analysis revealed that MS extensively reprograms the transcriptomes of tumor cells and cancer-associated fibroblasts (CAFs). In tumor cells, MS downregulates genes important for cell cycle progression inducing cytostasis. In CAFs, MS specifically represses the profibrotic transcription program responsive to TGF-beta, effectively inhibiting the fibrotic response. Consistent with this, MS blocks the activation of pancreatic stellate cells, the primary source for CAFs in PDAC, to repress the fibroblast-like phenotypes in these cells. Using an orthotopic transplantation model, we confirmed that MS treatment reduces tumor cell proliferation and decreases intratumoral fibrotic content. Importantly, we showed that MS substantially enhances chemocytotoxicity, synergizing with gemcitabine to reduce tumor burden in PDAC mouse models. Our study establishes a novel therapeutic strategy for PDAC based on epigenetic reprogramming induced by HDAC inhibition. Citation Format: Gaoyang Liang, Ruth Yu, Christopher Liddle, Morgan Truitt, Corina Antal, Annette Atkins, Ester Banayo, Michael Downes, Ronald Evans. Harnessing epigenetic reprogramming by histone deacetylase inhibitor MS275 for pancreatic cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5065. doi:10.1158/1538-7445.AM2017-5065

Histone deacetylase inhibitor MS-275 augments expression of a subset of IFN-γ-regulated genes in Toxoplasma gondii-infected macrophages but does not improve parasite control

Toxoplasma gondii is a ubiquitous apicomplexan parasite of mammals and birds and an important pathogen of humans. IFN-γ is the major mediator of host resistance against T. gondii but intriguingly, parasite-infected host cells including macrophages are severely impaired to respond to IFN-γ due to defective transcriptional activation of target genes. Here, we tested the possibility that the impaired responsiveness of T. gondii-infected macrophages to IFN-γ can be restored by inhibiting histone deacetylases (HDACs) using the class I-specific inhibitor MS-275. Treatment of RAW264.7 cells with MS-275 indeed increased MHC class II surface expression in infected and non-infected cells and largely abolished the inhibition of IFN-γ-regulated MHC class II expression exerted by T. gondii. Genome-wide transcriptome profiling revealed that MS-275 increased mean mRNA levels of IFN-γ-regulated genes particularly in non-infected macrophages. Transcript levels of 33% of IFN-γ secondary response genes but only those of a few primary response genes were also increased by MS-275 in T. gondii-infected cells. Importantly, the unresponsiveness of parasite-infected cells to IFN-γ was however not abolished by MS-275. Furthermore, MS-275 also up-regulated several anti-inflammatory cytokines or signaling molecules in T. gondii-infected macrophages. It additionally regulated expression of more than 2500 genes in non-infected macrophages expression of which was surprisingly counteracted by prior infection with T. gondii. FACS analysis and immunofluorescence microscopy revealed that MS-275 did not considerably diminish the number of parasite-positive cells or the intracellular replication in macrophages stimulated or not with IFN-γ. Thus, a supportive therapy using MS-275 appears inappropriate for treatment of toxoplasmosis.

Enhancing dopaminergic signaling and histone acetylation promotes long-term rescue of deficient fear extinction.

Extinction-based exposure therapy is used to treat anxiety- and trauma-related disorders; however, there is the need to improve its limited efficacy in individuals with impaired fear extinction learning and to promote greater protection against return-of-fear phenomena. Here, using 129S1/SvImJ mice, which display impaired fear extinction acquisition and extinction consolidation, we revealed that persistent and context-independent rescue of deficient fear extinction in these mice was associated with enhanced expression of dopamine-related genes, such as dopamine D1 (Drd1a) and -D2 (Drd2) receptor genes in the medial prefrontal cortex (mPFC) and amygdala, but not hippocampus. Moreover, enhanced histone acetylation was observed in the promoter of the extinction-regulated Drd2 gene in the mPFC, revealing a potential gene-regulatory mechanism. Although enhancing histone acetylation, via administering the histone deacetylase (HDAC) inhibitor MS-275, does not induce fear reduction during extinction training, it promoted enduring and context-independent rescue of deficient fear extinction consolidation/retrieval once extinction learning was initiated as shown following a mild conditioning protocol. This was associated with enhanced histone acetylation in neurons of the mPFC and amygdala. Finally, as a proof-of-principle, mimicking enhanced dopaminergic signaling by L-dopa treatment rescued deficient fear extinction and co-administration of MS-275 rendered this effect enduring and context-independent. In summary, current data reveal that combining dopaminergic and epigenetic mechanisms is a promising strategy to improve exposure-based behavior therapy in extinction-impaired individuals by initiating the formation of an enduring and context-independent fear-inhibitory memory.