Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Research Articles

KiSS-1 Modulation by Epigenetic Agents Improves the Cisplatin Sensitivity of Lung Cancer Cells.

Epigenetic alterations my play a role in the aggressive behavior of Non-Small Cell Lung Cancer (NSCLC). Treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA, vorinostat) has been reported to interfere with the proliferative and invasive potential of NSCLC cells. In addition, the DNA methyltransferase inhibitor azacytidine (AZA, vidaza) can modulate the levels of the metastasis suppressor KiSS-1. Thus, since cisplatin is still clinically available for NSCLC therapy, the aim of this study was to evaluate drug combinations between cisplatin and SAHA as well as AZA using cisplatin-sensitive H460 and -resistant H460/Pt NSCLC cells in relation to KiSS-1 modulation. An analysis of drug interaction according to the Combination-Index values indicated a more marked synergistic effect when the exposure to SAHA or AZA preceded cisplatin treatment with respect to a simultaneous schedule. A modulation of proteins involved in apoptosis (p53, Bax) was found in both sensitive and resistant cells, and compared to the treatment with epigenetic agents alone, the combination of cisplatin and SAHA or AZA increased apoptosis induction. The epigenetic treatments, both as single agents and in combination, increased the release of KiSS-1. Finally, the exposure of cisplatin-sensitive and -resistant cells to the kisspeptin KP10 enhanced cisplatin induced cell death. The efficacy of the combination of SAHA and cisplatin was tested in vivo after subcutaneous inoculum of parental and resistant cells in immunodeficient mice. A significant tumor volume inhibition was found when mice bearing advanced tumors were treated with the combination of SAHA and cisplatin according to the best schedule identified in cellular studies. These results, together with the available literature, support that epigenetic drugs are amenable for the combination treatment of NSCLC, including patients bearing cisplatin-resistant tumors.

A Combination of CPI-0610 and SAHA Induces Apoptosis through STAT3 and p38 Signalling Pathways in Diffuse Large B-cell Lymphoma Cells.

Although immunotherapies have greatly improved diffuse large B-cell lymphoma (DLBCL) prognosis, a proportion of patients remain to be relapsed or refractory. Therefore, the identification of novel therapeutic targets and drugs is urgently required. Inhibition of the bromodomain and extra-terminal (BET) proteins has been a promising therapeutic strategy for various haematologic cancers. CPI-0610 is a potent and selective BET inhibitor. The effects of CPI-0610 in DLBCL cells have not been reported yet. The aim of this study was to assess the effects of CPI-0610 in DLBCL and its underlying mechanisms. DLBCL cells were treated with CPI-0610, followed by measuring cell viability, cell cycle, apoptosis, autophagy, and specific cell signaling pathways. Moreover, immunodeficient mice were engrafted with SUDHL2 cells and then treated with CPI-0610 for analysis of tumor burden. We also analyzed the synergistic effect of CPI-0610 with histone deacetylase inhibitor suberoylanilide hydroxamic acid. The present study demonstrated that CPI-0610 displayed cell cytotoxicity by arresting the G1 cell cycle and inducing endogenous and exogenous apoptotic pathways. Additionally, CPI-0610 decreased BRD4 and c-Myc expressions and affected MAPK, JAK/STAT, and AKT signalling pathways in human DLBCL cells. An in vivo experiment exhibited that CPI-0610 decreased the primary tumour growth of the DLBCL xenograft model. Furthermore, the use of CPI-0610 in combination with suberoylanilide hydroxamic acid exhibited a specific synergistic effect in inducing apoptosis through the regulation of STAT3 and p38. Targeting BET may be an effective therapeutic strategy and potentiated by a combination with histone deacetylase inhibition in DLBCL.

Metabolomic, DNA Methylomic, and Transcriptomic Profiling of Suberoylanilide Hydroxamic Acid Effects on LPS-Exposed Lung Epithelial Cells.

Inflammation increases the risk of lung cancer and blocking inflammation could reduce the incidence of lung cancer. Herein, we demonstrate that histone deacetylase inhibitor suberoylanilide hydroxamic acid regulates metabolic rewiring and epigenetic reprogramming to attenuate lipopolysaccharide-driven inflammation in lung epithelial cells.

Epigenetic Modification of Mesenchymal Stromal Cells Derived from Bone Marrow and Embryonal Tumors to Facilitate Immunotherapeutic Approaches in Pediatric Malignancies.

Mesenchymal stromal cells (MSC) are part of the bone marrow architecture and contribute to the homeostasis of hematopoietic stem cells. Moreover, they are known to regulate immune effector cells. These properties of MSC are pivotal under physiologic conditions, and they may aberrantly also protect malignant cells. MSCs are also found in the leukemic stem cell niche of the bone marrow and as part of the tumor microenvironment. Here, they protect malignant cells from chemotherapeutic drugs and from immune effector cells in immunotherapeutic approaches. Modulation of these mechanisms may improve the efficacy of therapeutic regimens. We investigated the effect of the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA, Vorinostat™) on the immunomodulatory effect and cytokine profile of MSC derived from bone marrow and pediatric tumors. The immune phenotype of MSC was not markedly affected. SAHA-treated MSC showed reduced immunomodulatory effects on T cell proliferation and NK cell cytotoxicity. This effect was accompanied by an altered cytokine profile of MSC. While untreated MSC inhibited the production of certain pro-inflammatory cytokines, SAHA treatment led to a partial increase in IFNγ and TNFα secretion. These alterations of the immunosuppressive milieu might be beneficial for immunotherapeutic approaches.

The effects of epigenetic modifiers on the differentiation of human dental pulp stem cells into neural progenitor-like cells

Background: Human dental pulp stem cells (HDPSCs) may be differentiated into neural lineages. The main aim of the study was to assess the DNA demethylation and histone deacetylation inhibition on the differentiation of HDPSCs into neural progenitor-like cells (NPCs). Methods: HDPSCs were treated with 5-aza2′-deoxycytidine (AZA), DNA methylation inhibitor, and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) for 3 and 5 days followed by their differentiation into NPCs. The efficiency of the differentiation was evaluated by apoptosis, cellular proliferation, and relative expression of Nestin among the NPCs derived with the different treatments. Results: Five-day treatment of AZA was crucial for the more efficient demethylation of the HDPSCs. Analysis of the proliferation, apoptosis, and relative expression of the Nestin indicated that the AZA and SAHA neither enhance nor inhibit the differentiation of the HDPSCs into NPCs. Howevere, the expression of Nestin decreased at day 7 in NPCs derived with SAHAH treatment compared with NPCs derived with AZA treatmement. However, there was no difference in Nestin expression in any treatment-derived NPCs compared with control NPCs. All of the NPCs derived from all of the groups were able to differentiate into terminal neurons. Conclusion: Neither DNA demethylation nor the histone deacetylation has any main effects on proliferation and apoptosis during the differentiation of HDPSCs into NPCs. The only significant effect of the treatments was on the size of the NPCs at day 7; the SAHAH treatment had the smallest NPCs.

Improved oral bioavailability of poorly water-soluble vorinostat by self-microemulsifying drug delivery system

BackgroundVorinostat is a histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) with anticancer properties. However, it is plagued by low water solubility, low permeability (BCS class IV drug), and suboptimal pharmacokinetics. The purpose of the present study was to develop a self-microemulsifying drug delivery system (SMEDDS) to enhance the oral bioavailability of vorinostat. Capryol 90, labrasol, and polyethylene glycol (PEG 400) were selected as oil phase, surfactant, and co-surfactant, respectively. The vorinostat self-microemulsifying drug delivery systems were tested for self-microemulsifying time, phase separation, effect of pH, droplet size, zeta potential, dilution study, Fourier-transform infrared (FT-IR) spectroscopy analysis, and field emission scanning electron microscopy (FESEM). A rat model in vivo pharmacokinetic study was conducted for the optimized formulation against vorinostat pure drug powder.ResultsThe results from the characterization studies showed that the optimized formulation (F7) self-microemulsification time was 1.4 ± 0.05 min and no precipitation or phase separation was observed. The mean droplet size, polydispersity index (PDI), and zeta potential of the optimized formulation (F7) were found to be 272.9 ± 82.7 nm, 0.415, and − 57.2 mV, respectively. The pharmacokinetic parameters of the optimized formulation (F7) showed a 1.6-fold increase in maximum concentration (Cmax) and a 3.6-fold increase in area under the curve (AUC(0−∞)), in comparison with pure drug in suspension.ConclusionsThe findings suggest that SMEDDS formulation could be an effective method for increasing the oral bioavailability of vorinostat, which is poorly water soluble.

Suberoylanilide hydroxamic acid suppresses axonal damage and neurological dysfunction after subarachnoid hemorrhage via the HDAC1/HSP70/TDP-43 axis

Increased focus has been placed on the role of histone deacetylase inhibitors as crucial players in subarachnoid hemorrhage (SAH) progression. Therefore, this study was designed to expand the understanding of SAH by exploring the downstream mechanism of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in SAH. The expression of TDP-43 in patients with SAH and rat models of SAH was measured. Then, western blot analysis, immunofluorescence staining, and transmission electron microscope were used to investigate the in vitro effect of TDP-43 on a neuronal cell model of SAH established by oxyhemoglobin treatment. Immunofluorescence staining and coimmunoprecipitation assays were conducted to explore the relationship among histone deacetylase 1 (HDAC1), heat shock protein 70 (HSP70), and TDP-43. Furthermore, the in vivo effect of HDAC1 on SAH was investigated in rat models of SAH established by endovascular perforation. High expression of TDP-43 in the cerebrospinal fluid of patients with SAH and brain tissues of rat models of SAH was observed, and TDP-43 accumulation in the cytoplasm and the formation of inclusion bodies were responsible for axonal damage, abnormal nuclear membrane morphology, and apoptosis in neurons. TDP-43 degradation was promoted by the HDAC1 inhibitor SAHA via the acetylation of HSP70, alleviating SAH, and this effect was verified in vivo in rat models. In conclusion, SAHA relieved axonal damage and neurological dysfunction after SAH via the HSP70 acetylation-induced degradation of TDP-43, highlighting a novel therapeutic target for SAH.

Suberoylanilide hydroxamic acid induced microspore embryogenesis and promoted plantlet regeneration in ornamental kale (Brassica oleracea var. acephala).

Isolated Microspore Culture (IMC) is an efficient method to obtain the homozygous strain; however, it is difficult to apply in ornamental kale due to its low rate of microspore embryogenesis. Histone acetylation is an important epigenetic mechanism and may affect the changes of the microspore development pathway, promoting microspore embryogenesis. Here, microspores from three cut-flower ornamental kales, namely Crane Feather Queen (CFQ), Crane Pink (CP), and Crane Bicolor (CB), were treated with the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) to induce embryogenesis. The haploid 'CFQ' microspore plantlets were doubled with colchicine. The results for 'CFQ' revealed that, the appropriate concentration of SAHA was 0.03μM and obtained 17.27 embryos per bud. For 'CP,' the appropriate concentration of SAHA was 0.045μM and obtained 11.19 embryos per bud. For 'CB,' the appropriate concentration of SAHA was 0.045μM and obtained 6.10 embryos per bud. Haploid 'CFQ' microspore plantlets were treated with 75mg/L colchicine for 7 d and the doubling rate was 41.7%. Haploid 'CFQ' plantlets were treated with 1000mg/L colchicine by root-soaking for 4h and the doubling rate was 64.3%. SAHA could promote microspore embryogenesis, and colchicine root soaking was more effective than adding colchicine to the medium for haploid plantlet doubling in cut-flower ornamental kale.

LPS-induced lipid alterations in microglia revealed by MALDI mass spectrometry-based cell fingerprinting in neuroinflammation studies

Pathological microglia activation can promote neuroinflammation in many neurodegenerative diseases, and it has therefore emerged as a potential therapeutic target. Increasing evidence suggests alterations in lipid metabolism as modulators and indicators in microglia activation and its effector functions. Yet, how lipid dynamics in activated microglia is affected by inflammatory stimuli demands additional investigation to allow development of more effective therapies. Here, we report an extensive matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) whole cell fingerprinting workflow to investigate inflammation-associated lipid patterns in SIM-A9 microglial cells. By combining a platform of three synergistic MALDI MS technologies we could detect substantial differences in lipid profiles of lipopolysaccharide (LPS)- stimulated and unstimulated microglia-like cells leading to the identification of 21 potential inflammation-associated lipid markers. LPS-induced lipids in SIM-A9 microglial cells include phosphatidylcholines, lysophosphatidylcholines (LysoPC), sphingolipids, diacylglycerols and triacylglycerols. Moreover, MALDI MS-based cell lipid fingerprinting of LPS-stimulated SIM-A9 microglial cells pre-treated with the non-selective histone deacetylase inhibitor suberoylanilide hydroxamic acid revealed specific modulation of LPS-induced-glycerolipids and LysoPC(18:0) with a significant reduction of microglial inflammation response. Our study introduces MALDI MS as a complementary technology for fast and label-free investigation of stimulus-dependent changes in lipid patterns and their modulation by pharmaceutical agents.

Induction of funitatin A, a new polyketide from the Yellow River wetland-derived fungus Talaromyces funiculosus

• A novel polyketide was isolated from fungus Talaromyces funiculosus by adding the HDAC inhibitor SAHA. • The structure of the new compound was determined by analysis of 1D and 2D NMR and HRESIMS spectra. • The new compound was the first microbial natural product bearing a rare dimeric cyclopaldic acid structure. • The new compound showed moderate antimicrobial activity against the Proteus species and Escherichia coli . A new, highly modified fatty acid ester, funitatin A ( 1 ), was isolated from the Yellow River wetland-derived fungus Talaromyces funiculosus HPU-Y01 cultivated with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). The structure of 1 was established by analysis of NMR and HRESIMS data. Compound 1 featured a rare dimeric cyclopaldic acid structure and showed promising antimicrobial activity against both Proteus species and Escherichia coli with MIC values of 3.13 μM.

SAHA Inhibits Somatic Hyperalgesia Induced by Stress Combined with Orofacial Inflammation Through Targeting Different Spinal 5-HT Receptor Subtypes.

Epigenetic regulation of gene expression has been implicated in the development of chronic pain. However, little is known about whether this regulation is involved in the development and treatment of chronic pain comorbidities such as fibromyalgia syndrome (FMS) and temporomandibular disorder (TMD), a comorbidity predominantly occurring among women. Here we explored the impact of the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) on somatic hyperalgesia induced by stress or stress combined with orofacial inflammation, which mimicked the comorbidity of FMS and TMD in rats. Our data showed that somatic thermal hyperalgesia and mechanical allodynia induced by both conditions were completely prevented by intrathecal injection of SAHA, which upregulated 5-HT2C receptors but downregulated 5-HT3 receptors in the spinal dorsal horn. Subsequent spinal administration of RS102221 to inhibit 5-HT2C receptors or SR57227 to activate 5-HT3 receptors reversed the analgesic effect of SAHA under both conditions. These results indicate that SAHA attenuates the pro-nociceptive effects of stress combined with orofacial inflammation and the effects of stress alone. This likely occurs through epigenetic regulation of spinal 5-HT2C and 5-HT3 receptor expression, suggesting that SAHA has potential therapeutic value in FMS or comorbid FMS-TMD patients with somatic hyperalgesia.

Hydroxamate-Based Histone Deacetylase Inhibitors as Potential Mediators to Induce Dentine Regeneration by Human Dental Pulp Cell

Human dental pulp cells (hDPCs) have shown their plasticity when treated with the hydroxamate-based histone deacetylase (HDAC) inhibitor members, Trichostatin A (TSA), and suberoylanilide hydroxamic acid (SAHA). However, a comparison of their potency to stimulate odontoblast-like differentiation and mineralization has not been reported. The aim of our study was to confirm and compare these TSA and SAHA effects. Primary hDPCs cultured with/without various TSA or SAHA concentrations were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), ALP activity, alizarin red staining, and scratch wound healing assays. The inhibitory effect of TSA and SAHA on inhibiting the activity of HDAC was evaluated by HDAC activity assay. Odontoblast-related gene expression was determined using RT-qPCR. The MTT assay indicated that TSA or SAHA did not affect hDPC viability. TSA or SAHA treatment-induced odontoblast-like differentiation as evidenced by a significant increase in alkaline phosphatase activity and mineral deposition after 400 nM TSA or 1 μM SAHA treatment. A significant increase in nuclear factor I C, kruppel like factor 4, dentin matrix acidic phosphoprotein 1, dentin sialophosphoprotein, collagen type I alpha 1 chain, alkaline phosphatase (ALPL), integrin-binding sialoprotein, bone gamma-carboxyglutamate protein, vascular endothelial growth factor A, and cyclin-dependent kinase inhibitor 1A gene expression analyzed by RT-qPCR, at 24, 72 h, 7, and 10 days of treatment. The activity of HDAC in hDPCs culture was significantly inhibited after 72 h TSA and SAHA treatment. The scratch wound healing assay displayed enhanced cell migration at 72 h after TSA or SAHA treatment. Our findings demonstrated that TSA and SAHA have similar stimulatory effects in inducing HDPC odontogenic differentiation and mineralization and propose another potential use of TSA and SAHA to promote dentin regeneration.

MMP14 Contributes to HDAC Inhibition-Induced Radiosensitization of Glioblastoma.

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. Radiotherapy has long been an important treatment method of GBM. However, the intrinsic radioresistance of GBM cells is a key reason of poor therapeutic efficiency. Recently, many studies have shown that using the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) in radiotherapy may improve the prognosis of GBM patients, but the underlying molecular mechanisms remain unclear. In this study, Gene Expression Omnibus (GEO) datasets GSE153982 and GSE131956 were analyzed to evaluate radiation-induced changes of gene expression in GBM without or with SAHA treatment, respectively. Additionally, the survival-associated genes of GBM patients were screened using the Chinese Glioma Genome Atlas (CGGA) database. Taking the intersection of these three datasets, 11 survival-associated genes were discovered to be activated by irradiation and regulated by SAHA. The expressions of these genes were further verified in human GBM cell lines U251, T98G, and U251 homologous radioresistant cells (U251R) by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). It was found that MMP14 mRNA was considerably highly expressed in the radioresistant cell lines and was reduced by SAHA treatment. Transfection of MMP14 siRNA (siMMP14) suppressed cell survivals of these GBM cells after irradiation. Taken together, our results reveal for the first time that the MMP14 gene contributed to SAHA-induced radiosensitization of GBM.

Abstract 986: Induction of lytic cycle of Epstein-Barr virus by a novel organic compound through activation of the c-Jun N-terminal kinase pathway

Abstract The reactivation of lytic cycle of Epstein-Barr Virus (EBV) is an important component of the emerging lytic induction therapy to specifically target the virus in EBV-associated malignancies. The potency of the lytic induction is central to the effectiveness of the lytic induction therapy. It is hampered by cancer cells that are refractory to lytic induction. This study aims to elucidate novel pathways involved in inducing EBV lytic cycle in epithelial cancer cells using a small organic compound, E11 intermediate (E11.1), and develop new drug combinations to overcome the refractoriness of the cancer cells to lytic induction. E11.1 was found to be the active component in the original E11 compound which has a superior lytic induction capability in both gastric carcinoma (GC) and nasopharyngeal carcinoma (NPC) cells. Timepoint and dose dependent studies were performed to characterize E11.1's lytic reactivation kinetics of EBV in AGS-BDneo cells. Reactive oxygen species (ROS) scavengers and chemical pathway inhibitors were used to investigate the involvement of ROS and major cellular pathways in inducing lytic cycle of EBV by E11.1. Concomitant drug treatment of E11.1 and histone deacetylase (HDAC) inhibitor (suberoylanilide hydroxamic acid or romidepsin) was tested for synergistic action in lytic induction and cell death. E11.1 elicited a rapid kinetics of lytic induction through the activation of c-Jun N-terminal kinase (JNK) pathway in GC and NPC cells and induced the production of ROS and cell death at later timepoints. The combination of E11.1 and HDAC inhibitor reactivated the lytic cycle of EBV synergistically in both GC and NPC lines at 48 hours of treatment. In conclusion, we provided the evidence of activation of JNK pathway in the induction of EBV lytic cycle by E11.1 in EBV-positive epithelial malignancies. E11.1 and HDAC inhibitor induced the lytic cycle of EBV in EBV-positive epithelial cancer cells synergistically resulting in enhanced cell death. Citation Format: Mike Dorothea, Stephanie PT Yiu, Kwai Fung Hui, Alan K. S. Chiang. Induction of lytic cycle of Epstein-Barr virus by a novel organic compound through activation of the c-Jun N-terminal kinase pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 986.

In Vivo Evaluation of the Combined Anticancer Effects of Cisplatin and SAHA in Nonsmall Cell Lung Carcinoma Using [18F]FAHA and [18F]FDG PET/CT Imaging.

Combining standard drugs with low doses of histone deacetylase inhibitors (HDACIs) is a promising strategy to increase the efficacy of chemotherapy. The ability of well-tolerated doses of HDACIs that act as chemosensitizers for platinum-based chemotherapeutics has recently been proven in many types and stages of cancer in vitro and in vivo. Detection of changes in HDAC activity/expression may provide important prognostic and predictive information and influence treatment decision-making. Use of [18F] FAHA, a HDAC IIa-specific radionuclide, for molecular imaging may enable longitudinal, noninvasive assessment of HDAC activity/expression in metastatic cancer. We evaluated the synergistic anticancer effects of cisplatin and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in xenograft models of nonsmall cell lung cancer (NSCLC) using [18F] FAHA and [18F] FDG PET/CT imaging. Cisplatin alone significantly increased [18F] FAHA accumulation and reduced [18F] FDG accumulation in H441 and PC14 xenografts; coadministration of cisplatin and SAHA resulted in the opposite effects. Immunochemical staining for acetyl-histone H3 confirmed the PET/CT imaging findings. Moreover, SAHA had a more significant effect on the acetylome in PC14 (EGFR exon 19 deletion mutation) xenografts than H441 (wild-type EGFR and KRAS codon 12 mutant) xenografts. In conclusion, [18F] FAHA enables quantitative visualization of HDAC activity/expression in vivo, thus, may represent a clinically useful, noninvasive tool for the management of patients who may benefit from synergistic anticancer therapy.

Synergistic Combination of Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid and Natural Flavonoid Curcumin Exhibits Anticancer and Antibacterial Activity.

Curcumin is an effective anti-cancer agent used in thyroid cancer treatments. However, its use in clinical applications is limited due to low solubility and bioavailability. In this study, a novel combination strategy was applied by combining curcumin with Suberoylanilide Hydroxamic Acid (SAHA) to increase both bioavailability of curcumin and the efficiency of SAHA, which have limited efficiency when used alone. MTT assay was used to determine the cell viability of B-CPAP cells upon treatment with SAHA, curcumin and their combinations. Synergistic interactions between two agents were analyzed by Calcusyn software. Apoptosis and cell cycle assays were measured by flow cytometry. Expressions of apoptotic and cell cyclerelated proteins (PARP, P21/CDKN1A/WAF1, P27/KIP1) were examined by western blot analysis. Broth microdilution assay was performed to determine Minimum Inhibitory Concentration (MIC) values against S. aureus. Based on MTT assay, IC50 values for SAHA and curcumin were determined as 0.91μM and 20.97μM, respectively. The combination index CI value was determined as 0.891 in B-CPAP cells, which demonstrate synergistic activity. The apoptotic effect was achieved by combination treatment (51.85%) on B-CPAP cells using half of the dose required for SAHA and curcumin alone. Combination treatment showed a significant increase in the percentage of B-CPAP cells in the S-phase due to cell arrest. Cleaved-PARP, P21/CDKN1A/ WAF1 and P27/KIP1 protein expressions were upregulated. Curcumin was found to have better anti-microbial activity than SAHA as having a lower MIC value, and checkerboard synergy analysis revealed that the two compounds co-operate synergistically for the in vitro killing of S. aureus. In the present study, synergistic combinations of SAHA and curcumin were shown to have both anti-cancer and antibacterial activities that would provide a novel thyroid cancer treatment strategy.

Expression of DNA Methyltransferase 1 Is a Hallmark of Melanoma, Correlating with Proliferation and Response to B-Raf and Mitogen-Activated Protein Kinase Inhibition in Melanocytic Tumors

Aberrant DNA methylation is an epigenetic hallmark of melanoma, but the expression of DNA methyltransferase (Dnmt)-1 in melanocytic tumors is unknown. Dnmt1 expression was analyzed in primary melanocytes, melanoma cell lines, and 83 melanocytic tumors, and its associations with proliferation, mutational status, and response to B-Raf and mitogen-activated protein kinase kinase (MEK) inhibition were explored. Dnmt1 expression was increased incrementally from nevi [mean fluorescence intensity (MFI), 48.1; interquartile range, 41.7 to 59.6] to primary melanomas (MFI, 68.8; interquartile range, 58.4 to 77.0) and metastatic melanomas (MFI, 87.5; interquartile range, 77.1 to 114.5) (P<0.001). Dnmt1 expression was correlated with Ki-67 expression (Spearman correlation, 0.483; P<0.001) and was independent of BRAF mutation status (P=0.55). In BRAF-mutant melanoma, Dnmt1 was down-regulated during response to B-Raf and MEK inhibition and was again up-regulated on drug resistance invitro and invivo. Degradation of Dnmt1 by the histone deacetylase inhibitor suberoylanilide hydroxamic acid was associated with decreased cell viability in B-Raf inhibitor-sensitive and -resistant cell lines. This study demonstrates that Dnmt1 expression is correlated with proliferation in melanocytic tumors, is increased with melanoma progression, and is associated with response to B-Raf and MEK inhibition. Given its strong expression in metastatic melanoma, Dnmt1 may be a promising target for combined epigenetic and immunotherapy.

Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Improves Energetic Status and Cardiomyogenic Differentiation of Human Dilated Myocardium-Derived Primary Mesenchymal Cells.

Background. In this study the effect of histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) on the energetic status and cardiomyogenic differentiation of human healthy and dilated myocardium-derived mesenchymal stromal cells (hmMSC) have been investigated. Methods. The hmMSC were isolated from the healthy and dilated post-operation heart biopsies by explant outgrowth method. Cell proliferation, HDAC activity, mitochondrial membrane potential, and level of adenosine triphosphate (ATP) were evaluated. The effect of SAHA on mitochondrial parameters has been investigated also by Seahorse XF analyzer and cardiomyogenic differentiation was confirmed by the expression of transcription factor NK2 Homeobox 5 (Nkx2.5), cardiac troponin T and alpha cardiac actin at gene and protein levels. Results. Dilated myocardium-derived hmMSC had almost 1.5 folds higher HDAC activity compared to the healthy cells and significantly lower mitochondrial membrane potential and ATP level. HDAC class I and II inhibitor SAHA improved energetic status of mitochondria in dilated myocardium-isolated hmMSC and increased expression of cardiac specific proteins during 14 days of exposure of cells to SAHA. Conclusions. HDAC inhibitor SAHA can be a promising therapeutic for dilated cardiomyopathy (DCM). Dilated hmMSC exposed to SAHA improved energetic status and, subsequently, cardiomyogenic differentiation. Data suggest that human dilated myocardium-derived MSC still have cardio tissue regenerative potential, which might be stimulated by HDAC inhibitors.

Suberoylanilide Hydroxamic Acid Attenuates Interleukin-1β-Induced Interleukin-6 Upregulation by Inhibiting the Microtubule Affinity-Regulating Kinase 4/Nuclear Factor-κB Pathway in Synovium-Derived Mesenchymal Stem Cells from the Temporomandibular Joint.

Synovium-derived mesenchymal stem cells (SMSCs) can migrate to the site of destroyed condylar cartilage and differentiate into chondrocytes to repair temporomandibular joint (TMJ) damage. Interleukin (IL)-1β-induced IL-6 secretion has been shown to inhibit the chondrogenic potential of SMSCs. The histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) has recently been shown to be closely related to the inflammation induced by IL-1β. However, the relationship between SAHA and IL-6 secretion induced by IL-1β in SMSCs remains unclear. In this study, we evaluated the relationships between IL-1β and IL-6 in synovial specimens from patients with TMD and in model rats with osteoarthritis (OA). We found that IL-1β and IL-6 were positively correlated and that IL-6 expression in SMSCs increased with IL-1β stimulation in vitro. Moreover, microtubule affinity-regulating kinase 4 (MARK4) was significantly upregulated in IL-1β-stimulated SMSCs and in the synovium of rats with OA. MARK4 knockdown inhibited IL-6 secretion and nuclear factor (NF)-κB pathway activation in IL-1β-stimulated SMSCs. SAHA attenuated IL-6 secretion in IL-1β-induced SMSCs through NF-κB pathway inhibition, and MARK4 was also downregulated in SAHA-treated SMSCs. However, inhibition of the NF-κB pathway did not suppress MARK4 expression. Thus, these results showed that SAHA attenuated IL-6 secretion in IL-1β-induced SMSCs through inhibition of the MARK4/NF-κB pathway.

Inhibition of Histone Deacetylase Reinstates Hippocampus-Dependent Long-Term Synaptic Plasticity and Associative Memory in Sleep-Deprived Mice

Sleep plays an important role in the establishment of long-term memory; as such, lack of sleep severely impacts domains of our health including cognitive function. Epigenetic mechanisms regulate gene transcription and protein synthesis, playing a critical role in the modulation of long-term synaptic plasticity and memory. Recent evidences indicate that transcriptional dysregulation as a result of sleep deprivation (SD) may contribute to deficits in plasticity and memory function. The histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA), also known as Vorinostat, a clinically approved drug for human use, has been shown to ameliorate cognitive deficits in several neurological disease models. To further explore the therapeutic effect of SAHA, we have examined its potential role in improving the SD-mediated impairments in long-term plasticity, associative plasticity, and associative memory. Here we show that SAHA preserves long-term plasticity, associative plasticity, and associative memory in SD hippocampus. Furthermore, we find that SAHA prevents SD-mediated epigenetic changes by upregulating histone acetylation, hence preserving the ERK-cAMP-responsive element-binding protein (CREB)/CREB-binding protein-brain-derived neurotrophic factor pathway in the hippocampus. These data demonstrate that modifying epigenetic mechanisms via SAHA can prevent or reverse impairments in long-term plasticity and memory that result from sleep loss. Thus, SAHA could be a potential therapeutic agent in improving SD-related memory deficits.