Science.gov

Sample records for acid hdac inhibitor

  1. Structural Requirements of HDAC Inhibitors: SAHA Analogs Functionalized Adjacent to the Hydroxamic Acid

    PubMed Central

    Bieliauskas, Anton V.; Weerasinghe, Sujith V. W.; Pflum, Mary Kay H.

    2007-01-01

    Inhibitors of histone deacetylase (HDAC) proteins such as suberoylanilide hydroxamic acid (SAHA) have emerged as effective therapeutic anti-cancer agents. To better understand the structural requirements of HDAC inhibitors, a small molecule library with a variety of substituents attached adjacent to the metal binding hydroxamic acid of SAHA was synthesized. The presence of a substituent adjacent to the hydroxamic acid led to an 800 to 5000-fold decrease in inhibition compared to SAHA. The observed results have implications for drug design, suggesting that HDAC inhibitors with substituents near the metal binding moiety will have inhibitory activities in the μM rather than nM range. PMID:17307359

  2. Structure of 'linkerless' hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket.

    PubMed

    Tabackman, Alexa A; Frankson, Rochelle; Marsan, Eric S; Perry, Kay; Cole, Kathryn E

    2016-09-01

    Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsin (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition.

  3. Olaparib hydroxamic acid derivatives as dual PARP and HDAC inhibitors for cancer therapy.

    PubMed

    Yuan, Zigao; Chen, Shaopeng; Sun, Qinsheng; Wang, Ning; Li, Dan; Miao, Shuangshuang; Gao, Chunmei; Chen, Yuzong; Tan, Chunyan; Jiang, Yuyang

    2017-08-01

    Olaparib was the first PARP inhibitor approved by the FDA for patients with BRCA-mutated ovarian cancer. Recent studies have demonstrated enhanced anticancer effects of combination therapy consisting of olaparib and HDAC inhibitors. Herein, based on rational drug design strategy, hydroxamic acid derivatives of olaparib were constructed as dual PARP and HDAC inhibitors. These hybrid compounds showed potent inhibitory activities against PARP1/2 and HDAC1/6 with IC50 values in the nanomolar range. Furthermore, compound P1 exhibited broad-spectrum antiproliferative activities in selected human cancer cell lines. Specially, P1 showed more potent activity than olaparib and SAHA in cancer cells MDA-MB-231, HCC1937 and Raji, and 4.1-fold less cytotoxicity compared with SAHA to normal cells MCF-10A. Further mechanism study indicated that P1 could induce the cleavage of PARP and the hyperacetylation of histones, increase the expression of DNA damage biomarker γ-H2AX, decrease the level of BRCA1 and RAD51, and regulate tumor cell growth and apoptosis through modulating both mitochondrial- and death receptor-mediated pathways. Therefore, our study suggested that compounds targeting PARP and HDAC concurrently might be a practical approach for cancer therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Design, synthesis and biological evaluation of thienopyrimidine hydroxamic acid based derivatives as structurally novel histone deacetylase (HDAC) inhibitors.

    PubMed

    Wang, Jiang; Su, Mingbo; Li, Tingting; Gao, Anhui; Yang, Wei; Sheng, Li; Zang, Yi; Li, Jia; Liu, Hong

    2017-03-10

    New thienopyrimidine hydroxamic acid derivatives as HDACs inhibitors were designed, synthesized and evaluated. All compounds were evaluated for their ability to inhibit recombinant human HDAC1, HDAC3, and HDAC6 isoforms and in vitro anti-proliferative activity on tumor cell lines RMPI 8226 and HCT 116. Most of these compounds displayed good to excellent inhibitory activities against HDACs. The IC50 values of compound 9m against HDAC1, HDAC3, and HDAC6 was 29.81 ± 0.52 nM, 24.71 ± 1.16 nM, and 21.29 ± 0.32 nM. Most of these compounds showed strong anti-proliferative activity against human cancer cell lines including RMPI 8226 and HCT 116. The IC50 values of compound 9m against RPMI 8226 and HCT 116 proliferation were 0.97 ± 0.072 μM and 1.01 ± 0.033 μM, respectively. In addition, compound 9m noticeably up-regulated the level of histone H3 acetylation at the low concentration of 0.3 μM.

  5. Quinolone-based HDAC inhibitors.

    PubMed

    Balasubramanian, Gopalan; Kilambi, Narasimhan; Rathinasamy, Suresh; Rajendran, Praveen; Narayanan, Shridhar; Rajagopal, Sridharan

    2014-08-01

    HDAC inhibitors emerged as promising drug candidates in combating wide variety of cancers. At present, two of the compounds SAHA and Romidepsin were approved by FDA for cutaneous T-cell lymphoma and many are in various clinical phases. A new quinolone cap structure was explored with hydroxamic acid as zinc-binding group (ZBG). The pan HDAC inhibitory and antiproliferative activities against three human cancer cell lines HCT-116 (colon), NCI-H460 (lung) and U251 (glioblastoma) of the compounds (4a-4w) were evaluated. Introduction of heterocyclic amines in CAP region increased the enzyme inhibitory and antiproliferative activities and few of the compounds tested are metabolically stable in both MLM and HLM.

  6. Inhibition of leukemic cells by valproic acid, an HDAC inhibitor, in xenograft tumors

    PubMed Central

    Zhang, Zhihua; Hao, Changlai; Wang, Lihong; Liu, Peng; Zhao, Lei; Zhu, Cuimin; Tian, Xia

    2013-01-01

    The chimeric fusion protein, AML1-ETO, generated by translocation of t(8;21), abnormally recruits histone deacetylase (HDAC) to the promoters of AML1 target genes, resulting in transcriptional repression of the target genes and development of t(8;21) acute myeloid leukemia. Abnormal expression of cyclin-dependent kinase inhibitors, especially p21, is considered a possible mechanism of the arrested maturation and differentiation seen in leukemia cells. A new generation of HDAC inhibitors is becoming an increasing focus of attention for their ability to induce differentiation and apoptosis in tumor cells and to block the cell cycle. Our previous research had demonstrated that valproic acid induces G0/G1 arrest of Kasumi-1 cells in t(8;21) acute myeloid leukemia. In this study, we further confirmed that valproic acid inhibits the growth of Kasumi-1 cells in a murine xenograft tumor model, and that this occurs via upregulation of histone acetylation in the p21 promoter region, enhancement of p21 expression, suppression of phosphorylation of retinoblastoma protein, blocking of transcription activated by E2F, and induction of G0/G1 arrest. PMID:23836985

  7. Synthesis of ST7612AA1, a Novel Oral HDAC Inhibitor, via Radical 
Thioacetic Acid Addition

    PubMed Central

    Battistuzzi, Gianfranco; Giannini, Giuseppe

    2016-01-01

    Abstract: Background In the expanding field of anticancer drugs, HDAC inhibitors are playing an increasingly important role. To date, four/five HDAC inhibitors have been approved by FDA. All these compounds fit the widely accepted HDAC inhibitors pharmacophore model characterized by a cap group, a linker chain and a zinc binding group (ZBG), able to bind the Zn2+ ion in a pocket of the HDAC active site. Romidepsin, a natural compound, is the only thiol derivative. We have selected a new class of synthetic HDAC inhibitors, the thio-ω(lactam-carboxamide) derivatives, with ST7612AA1 as drug candidate, pan-inhibitor active in the range of single- to two-digit nanomolar concentrations. Preliminary results of a synthetic optimization attempt towards a fast scale-up process are here proposed. Methods In the four steps of synthesis, from unsaturated amino acid intermediate to the final product, we explored different synthetic conditions in order to have a transferable process for a scale-up synthetic laboratory. Results In the first step, isobutyl chloroformate was used and, after a simple work up with 1M HCl, 2 (96% yield) was obtained as a white solid, which was used directly in the next step. For thioacetic acid addition to the double bond of intermediate 2, two different routes were possible, with addition reaction in the first (D’) or last step (D). Reactions of 2 to give 5 or of 4 to give ST7612AA1 were both performed in dioxane. Reactions were fast and did not need the usually advised radical quenching with cyclohexene. The corresponding products were obtained in good yields (step D’, 89%; step D, 81%) after a flash chromatography. Conclusion: ST7612AA1 , a thiol derivative prodrug of ST7464AA1, is the first of a new generation of HDAC inhibitors, very potent, orally administered, and well tolerated. Here, we have identified a synthetic route, competitive, versatile and easily transferable to industrial processes. PMID:27917100

  8. In silico modification of suberoylanilide hydroxamic acid (SAHA) as potential inhibitor for class II histone deacetylase (HDAC)

    PubMed Central

    2011-01-01

    Background The cervical cancer is the second most prevalent cancer for the woman in the world. It is caused by the oncogenic human papilloma virus (HPV). The inhibition activity of histone deacetylase (HDAC) is a potential strategy for cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is widely known as a low toxicity HDAC inhibitor. This research presents in silico SAHA modification by utilizing triazole, in order to obtain a better inhibitor. We conducted docking of the SAHA inhibitor and 12 modified versions to six class II HDAC enzymes, and then proceeded with drug scanning of each one of them. Results The docking results show that the 12 modified inhibitors have much better binding affinity and inhibition potential than SAHA. Based on drug scan analysis, six of the modified inhibitors have robust pharmacological attributes, as revealed by drug likeness, drug score, oral bioavailability, and toxicity levels. Conclusions The binding affinity, free energy and drug scan screening of the best inhibitors have shown that 1c and 2c modified inhibitors are the best ones to inhibit class II HDAC. PMID:22373132

  9. In silico modification of suberoylanilide hydroxamic acid (SAHA) as potential inhibitor for class II histone deacetylase (HDAC).

    PubMed

    Tambunan, Usman S F; Bramantya, N; Parikesit, Arli A

    2011-01-01

    The cervical cancer is the second most prevalent cancer for the woman in the world. It is caused by the oncogenic human papilloma virus (HPV). The inhibition activity of histone deacetylase (HDAC) is a potential strategy for cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is widely known as a low toxicity HDAC inhibitor. This research presents in silico SAHA modification by utilizing triazole, in order to obtain a better inhibitor. We conducted docking of the SAHA inhibitor and 12 modified versions to six class II HDAC enzymes, and then proceeded with drug scanning of each one of them. The docking results show that the 12 modified inhibitors have much better binding affinity and inhibition potential than SAHA. Based on drug scan analysis, six of the modified inhibitors have robust pharmacological attributes, as revealed by drug likeness, drug score, oral bioavailability, and toxicity levels. The binding affinity, free energy and drug scan screening of the best inhibitors have shown that 1c and 2c modified inhibitors are the best ones to inhibit class II HDAC.

  10. Discovery, synthesis, and pharmacological evaluation of spiropiperidine hydroxamic acid based derivatives as structurally novel histone deacetylase (HDAC) inhibitors.

    PubMed

    Varasi, Mario; Thaler, Florian; Abate, Agnese; Bigogno, Chiara; Boggio, Roberto; Carenzi, Giacomo; Cataudella, Tiziana; Dal Zuffo, Roberto; Fulco, Maria Carmela; Rozio, Marco Giulio; Mai, Antonello; Dondio, Giulio; Minucci, Saverio; Mercurio, Ciro

    2011-04-28

    New spiro[chromane-2,4'-piperidine] and spiro[benzofuran-2,4'-piperidine] hydroxamic acid derivatives as HDAC inhibitors have been identified by combining privileged structures with a hydroxamic acid moiety as zinc binding group. The compounds were evaluated for their ability to inhibit nuclear extract HDACs and for their in vitro antiproliferative activity on different tumor cell lines. This work resulted in the discovery of spirocycle 30d that shows good oral bioavailability and tumor growth inhibition in an HCT-116 murine xenograft model.

  11. Valproic Acid as a Potential Inhibitor of Plasmodium falciparum Histone Deacetylase 1 (PfHDAC1): An in Silico Approach

    PubMed Central

    Elbadawi, Mohamed A. Abdallah; Awadalla, Mohamed Khalid Alhaj; Abdel Hamid, Muzamil Mahdi; Mohamed, Magdi Awadalla; Awad, Talal Ahmed

    2015-01-01

    A new Plasmodium falciparum histone deacetylase1 (PfHDAC1) homology model was built based on the highest sequence identity available template human histone deacetylase 2 structure. The generated model was carefully evaluated for stereochemical accuracy, folding correctness and overall structure quality. All evaluations were acceptable and consistent. Docking a group of hydroxamic acid histone deacetylase inhibitors and valproic acid has shown binding poses that agree well with inhibitor-bound histone deacetylase-solved structural interactions. Docking affinity dG scores were in agreement with available experimental binding affinities. Further, enzyme-ligand complex stability and reliability were investigated by running 5-nanosecond molecular dynamics simulations. Thorough analysis of the simulation trajectories has shown that enzyme-ligand complexes were stable during the simulation period. Interestingly, the calculated theoretical binding energies of the docked hydroxamic acid inhibitors have shown that the model can discriminate between strong and weaker inhibitors and agrees well with the experimental affinities reported in the literature. The model and the docking methodology can be used in screening virtual libraries for PfHDAC1 inhibitors, since the docking scores have ranked ligands in accordance with experimental binding affinities. Valproic acid calculated theoretical binding energy suggests that it may inhibit PfHDAC1. PMID:25679451

  12. Structure of ‘linkerless’ hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket

    SciTech Connect

    Tabackman, Alexa A.; Frankson, Rochelle; Marsan, Eric S.; Perry, Kay; Cole, Kathryn E.

    2016-11-04

    Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsin (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98 Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition.

  13. HDAC and HDAC Inhibitor: From Cancer to Cardiovascular Diseases

    PubMed Central

    Yoon, Somy

    2016-01-01

    Histone deacetylases (HDACs) are epigenetic regulators that regulate the histone tail, chromatin conformation, protein-DNA interaction, and even transcription. HDACs are also post-transcriptional modifiers that regulate the protein acetylation implicated in several pathophysiologic states. HDAC inhibitors have been highlighted as a novel category of anti-cancer drugs. To date, four HDAC inhibitors, Vorinostat, Romidepsin, Panobinostat, and Belinostat, have been approved by the United States Food and Drug Administration. Principally, these HDAC inhibitors are used for hematologic cancers in clinic with less severe side effects. Clinical trials are continuously expanding to address other types of cancer and also nonmalignant diseases. HDAC inhibition also results in beneficial outcomes in various types of neurodegenerative diseases, inflammation disorders, and cardiovascular diseases. In this review, we will briefly discuss 1) the roles of HDACs in the acquisition of a cancer's phenotype and the general outcome of the HDAC inhibitors in cancer, 2) the functional relevance of HDACs in cardiovascular diseases and the possible therapeutic implications of HDAC inhibitors in cardiovascular disease. PMID:26865995

  14. LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington's Disease.

    PubMed

    Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B; Kazantsev, Aleksey G; Hersch, Steven

    2016-12-15

    Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington's disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates.

  15. LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington’s Disease

    PubMed Central

    Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B.; Kazantsev, Aleksey G.; Hersch, Steven

    2016-01-01

    Background: Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington’s disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. Objective: In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. Method: The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. Results: We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Conclusions: Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates. PMID:27983565

  16. In-Bead Screening of Hydroxamic Acids for the Identification of HDAC Inhibitors.

    PubMed

    Qvortrup, Katrine; Nielsen, Thomas E

    2016-03-24

    A one bead-one compound screening format is presented. Following solid-phase synthesis on a photolabile linker, library compounds were readily released and screened inside polymer beads. The release of screening compounds was readily controlled by varying photolysis time and light intensity. Dose-response experiments were carried out to effectively distinguish high- and low-affinity ligands. A library containing 55,800 compounds was synthesized and screened in a fluorometric assay, thereby identifying potent HDAC inhibitors with IC50 values in the nanomolar range. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Cellular prostatic acid phosphatase (cPAcP) serves as a useful biomarker of histone deacetylase (HDAC) inhibitors in prostate cancer cell growth suppression.

    PubMed

    Chou, Yu-Wei; Lin, Fen-Fen; Muniyan, Sakthivel; Lin, Frank C; Chen, Ching-Shih; Wang, Jue; Huang, Chao-Cheng; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the most commonly diagnosed solid tumor and the second leading cancer death in the United States, and also one of the major cancer-related deaths in Chinese. Androgen deprivation therapy (ADT) is the first line treatment for metastatic PCa. PCa ultimately relapses with subsequent ADT treatment failure and becomes castrate-resistant (CR). It is important to develop effective therapies with a surrogate marker towards CR PCa. Histone deacetylase (HDAC) inhibitors were examined to determine their effects in androgen receptor (AR)/cellular prostatic acid phosphatase (cPAcP)-positive PCa cells, including LNCaP C-33, C-81, C4-2 and C4-2B and MDA PCa2b androgen-sensitive and androgen-independent cells, and AR/cPAcP-negative PCa cells, including PC-3 and DU 145 cells. Cell growth was determined by cell number counting. Western blot analyses were carried out to determine AR, cPAcP and PSA protein levels. cPAcP protein level was increased by HDAC inhibitor treatment. Valproic acid, a HDAC inhibitor, suppressed the growth of AR/cPAcP-positive PCa cells by over 50% in steroid-reduced conditions, higher than on AR/cPAcP-negative PCa cells. Further, HDAC inhibitor pretreatments increased androgen responsiveness as demonstrated by PSA protein level quantitation. Our results clearly demonstrate that HDAC inhibitors can induce cPAcP protein level, increase androgen responsiveness, and exhibit higher inhibitory activities on AR/cPAcP-positive PCa cells than on AR/cPAcP-negative PCa cells. Upon HDAC inhibitor pretreatment, PSA level was greatly elevated by androgens. This data indicates the potential clinical importance of cPAcP serving as a useful biomarker in the identification of PCa patient sub-population suitable for HDAC inhibitor treatment.

  18. HDAC Inhibitors as Novel Anti-Cancer Therapeutics.

    PubMed

    De Souza, Cristabelle; Chatterji, Biswa Prasun

    2015-01-01

    Malignant growth of cells is a condition characterized by unchecked cellular proliferation, genetic instability and epigenetic dysregulation. Up-regulated HDAC (Histone Deacetylase) enzyme activity is associated with a closed chromatin assembly and subsequent gene repression, forming a characteristic feature of malignantly transformed cells. Novel therapeutics are now targeting the zinc containing HDAC enzymes for treating various types of cancers. Recently, a spate of drugs acting via HDAC inhibition have been undergoing clinical trials and several patents present exciting molecules like PCI-24781 (Abexinostat), ITF- 2357 (Givinostat); MS-275 (Entinostat), MGCD 0103 (Mocetinostat), LBH-589 (Panobinostat), FK228 (Romidepsin), PXD-101 (Belinostat) and Valproic Acid to be used as alternatives or adjuvants to traditional chemotherapeutics. However, only three HDAC inhibitors have acquired FDA approval till date. Recently, PXD-101 obtained FDA approval for the treatment of Refractory or Relapsed Peripheral T cell lymphoma. The current article reviews patents that have introduced novel molecules that are HDAC isoform specific, superior to first generation HDAC inhibitors like SAHA (Suberoylanilide Hydroxamic Acid) and TSA (Trichostatin A) and can be modified structurally to reduce toxic side effects and increase specificity. These molecules can combine the best characteristics of an ideal HDAC inhibiting drug either as monotherapy or in combinatorial therapy for cancer treatment thus, indicating promise to be included in the next generation of target specific HDAC inhibiting drugs.

  19. The histone deacetylase inhibitor valproic acid inhibits NKG2D expression in natural killer cells through suppression of STAT3 and HDAC3

    PubMed Central

    Ni, Lulu; Wang, Lixin; Yao, Chao; Ni, Zhongya; Liu, Fei; Gong, Chenyuan; Zhu, Xiaowen; Yan, Xuewei; Watowich, Stephanie S.; Lee, Dean A.; Zhu, Shiguo

    2017-01-01

    NKG2D is a major activating receptor of NK cells and plays a critical role in tumor immunosurveillance. NKG2D expression in NK cells is inhibited by the histone deacetylase (HDAC) inhibitor valproic acid (VPA) and enhanced by the narrow-spectrum HDAC inhibitor entinostat. We previously demonstrated that entinostat enhanced NKG2D transcription by increasing acetylation of Histones H3 and H4. However, the mechanism by which VPA reduces NKG2D expression in NK cells is not known. We have also shown that NKG2D transcription is regulated by STAT3 phosphorylation. In this study, we investigated regulation of NKG2D expression in NK cells by VPA and entinostat by assessing protein expression, phosphorylation, and interaction of HDACs and STAT3. We find that VPA selectively inhibits STAT3 tyrosine705 phosphorylation, but entinostat does not. STAT3 complexes with HDAC3, and HDAC3 inhibition represses STAT3 phosphorylation and therefore NKG2D expression. NK cells from STAT3 wild-type mice downregulate NKG2D in response to VPA, but not NK cells from STAT3 knockout mice. These results show that VPA is a potent inhibitor of STAT3 phosphorylation and demonstrate that histone acetylation and STAT3 tyrosine705 phosphorylation cooperate in regulating NKG2D expression in NK cells. PMID:28338101

  20. In silico modification of Zn2+ binding group of suberoylanilide hydroxamic acid (SAHA) by organoselenium compounds as Homo sapiens class II HDAC inhibitor of cervical cancer

    NASA Astrophysics Data System (ADS)

    Sumo Friend Tambunan, Usman; Bakri, Ridla; Aditya Parikesit, Arli; Ariyani, Titin; Dyah Puspitasari, Ratih; Kerami, Djati

    2016-02-01

    Cervical cancer is the most common cancer in women, and ranks seventh of all cancers worldwide, with 529000 cases in 2008 and more than 85% cases occur in developing countries. One way to treat this cancer is through the inhibition of HDAC enzymes which play a strategic role in the regulation of gene expression. Suberoyl Anilide Hydroxamic Acid (SAHA) or Vorinostat is a drug which commercially available to treat the cancer, but still has some side effects. This research present in silico SAHA modification in Zinc Binding Group (ZBG) by organoselenium compound to get ligands which less side effect. From molecular docking simulation, and interaction analysis, there are five best ligands, namely CC27, HA27, HB28, IB25, and KA7. These five ligands have better binding affinity than the standards, and also have interaction with Zn2+ cofactor of inhibited HDAC enzymes. This research is expected to produce more potent HDAC inhibitor as novel drug for cervical cancer treatment.

  1. A Linker for the Solid-Phase Synthesis of Hydroxamic Acids and Identification of HDAC6 Inhibitors.

    PubMed

    Bang, Claus G; Jensen, Jakob F; O'Hanlon Cohrt, Emil; Olsen, Lasse B; Siyum, Saba G; Mortensen, Kim T; Skovgaard, Tine; Berthelsen, Jens; Yang, Liang; Givskov, Michael; Qvortrup, Katrine; Nielsen, Thomas E

    2017-09-06

    We herein present broadly useful, readily available and nonintegral hydroxylamine linkers for the routine solid-phase synthesis of hydroxamic acids. The developed protocols enable the efficient synthesis and release of a wide range of hydroxamic acids from various resins, relying on high control and flexibility with respect to reagents and synthetic processes. A trityl-based hydroxylamine linker was used to synthesize a library of peptide hydroxamic acids. The inhibitory effects of the compounds were examined for seven HDAC enzyme subtypes using a chemiluminescence-based assay.

  2. Resistance after Chronic Application of the HDAC-Inhibitor Valproic Acid Is Associated with Elevated Akt Activation in Renal Cell Carcinoma In Vivo

    PubMed Central

    Juengel, Eva; Makarević, Jasmina; Tsaur, Igor; Bartsch, Georg; Nelson, Karen; Haferkamp, Axel; Blaheta, Roman A.

    2013-01-01

    Targeted drugs have significantly improved the therapeutic options for advanced renal cell carcinoma (RCC). However, resistance often develops, negating the benefit of these agents. In the present study, the molecular mechanisms of acquired resistance towards the histone deacetylase (HDAC) inhibitor valproic acid (VPA) in a RCC in vivo model were investigated. NMRI:nu/nu mice were transplanted with Caki-1 RCC cells and then treated with VPA (200 mg/kg/day). Controls remained untreated. Based on tumor growth dynamics, the mice were divided into “responders” and “non-responders” to VPA. Histone H3 and H4 acetylation and expression of cell signaling and cell cycle regulating proteins in the RCC mouse tumors were evaluated by Western blotting. Tumor growth of VPA responders was significantly diminished, whereas that of VPA non-responders even exceeded control values. Cdk1, 2 and 4 proteins were strongly enhanced in the non-responders. Importantly, Akt expression and activity were massively up-regulated in the tumors of the VPA non-responders. Chronic application (12 weeks) of VPA to Caki-1 cells in vitro evoked a distinct elevation of Akt activity and cancer cells no longer responded with cell growth reduction, compared to the short 2 week treatment. We assume that chronic use of an HDAC-inhibitor is associated with (re)-activation of Akt, which may be involved in resistance development. Consequently, combined blockade of both HDAC and Akt may delay or prevent drug resistance in RCC. PMID:23372654

  3. Design, synthesis and biological evaluation of a phenyl butyric acid derivative, N-(4-chlorophenyl)-4-phenylbutanamide: A HDAC6 inhibitor with anti-proliferative activity on cervix cancer and leukemia cells.

    PubMed

    Alberto, Rodríguez-Fonseca Rolando; Yudibeth, Sixto-López; Jonathan, Fragoso-Vázquez M; Raúl, Flores-Mejía; Cristina, Cabrera-Pérez Laura; Ismael, Vázquez-Moctezuma; Cecilia, Rosales-Hernández Martha; Martiniano, Bello; Martínez-Archundia, M; Guadalupe, Trujillo-Ferrara José; Elvia, Becerra-Martínez; José, Correa-Basurto

    2017-01-02

    The epigenetic regulation of genes in cancer could be targeted by inhibiting Histone deacetylase 6 (HDAC6), an enzyme involved in several types of cancer such as lymphoma, leukemia, ovarian cancer, etc. Through in silico methods, a set of Phenyl butyric acid derivatives with possible HDAC6 inhibitory activity were designed, rendering monophenylamides and biphenylamides using tubacin (HDAC6 selective inhibitor) as reference. The target compounds were submitted to theoretical ADMET analyses and their binding properties on different HDAC6 conformers were evaluated through docking calculations. These in silico studies allowed us to identify a compound named B-R2B. In order to have more information about the B-R2B binding recognition properties on HDAC6, the B-R2B-HDAC6 complex was submitted through 100 ns-long Molecular Dynamics (MD) simulation coupled to MMGBSA approach, revealing that B-R2B is located at the entrance of HDAC6 active pocket, blocking the passage of the substrate without reaching the HDAC6 binding site. Based on these results, B-R2B was synthesized, characterized and biologically tested. The HDAC6 fluorometric drug discovery kit Fluor-de-Lys (ENZO Life Sciences Inc.) was used to determine the HDAC6 human inhibitory activity (IC50 value) of B-R2B compound. In addition, B-R2B show IC50 values on cancer cell lines (HeLa; IC50 = 72.6 µM), acute myeloid leukemia (THP-1; IC50 = 16.5 µM), human mast leukemia (HMC; IC50 = 79.29 µM) and chronic myelogenous leukemia (Kasumi; IC50 = 101 µM). In conclusion, these results show that B-R2B is a HDAC6 inhibitor, specifically a non-competitive type in a similar way that tubacin does, according to MD simulations.

  4. Translating HDAC inhibitors in Friedreich's ataxia.

    PubMed

    Soragni, Elisabetta; Gottesfeld, Joel M

    2016-01-01

    Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by expansion of a GAA·TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Repeat expansion results in transcriptional silencing through an epigenetic mechanism, resulting in significant decreases in frataxin protein in affected individuals. Since the FXN protein coding sequence is unchanged in FRDA, an attractive therapeutic approach for this disease would be to increase transcription of pathogenic alleles with small molecules that target the silencing mechanism. We review the evidence that histone postsynthetic modifications and heterochromatin formation are responsible for FXN gene silencing in FRDA, along with efforts to reverse silencing with drugs that target histone modifying enzymes. Chemical and pharmacological properties of histone deacetylase (HDAC) inhibitors, which reverse silencing, together with enzyme target profiles and kinetics of inhibition, are discussed. Two HDAC inhibitors have been studied in human clinical trials and the properties of these compounds are compared and contrasted. Efforts to improve on bioavailability, metabolic stability, and target activity are reviewed. 2-aminobenzamide class I HDAC inhibitors are attractive therapeutic small molecules for FRDA. These molecules increase FXN gene expression in human neuronal cells derived from patient induced pluripotent stem cells, and in two mouse models for the disease, as well as in circulating lymphocytes in patients treated in a phase Ib clinical trial. Medicinal chemistry efforts have identified compounds with improved brain penetration, metabolic stability and efficacy in the human neuronal cell model. A clinical candidate will soon be identified for further human testing.

  5. Valproic Acid and Other HDAC Inhibitors Upregulate FGF21 Gene Expression and Promote Process Elongation in Glia by Inhibiting HDAC2 and 3

    PubMed Central

    Wang, Junyu; Wang, Zhifei; Liao, Hsiao-Mei; Wei, Monica; Leeds, Peter

    2016-01-01

    Background: Fibroblast growth factor 21, a novel regulator of glucose and lipid metabolism, has robust protective properties in neurons. However, its expression and function in glia are unknown. Valproic acid, a mood stabilizer and anticonvulsant, is a histone deacetylase inhibitor and a dynamic gene regulator. We investigated whether histone deacetylase inhibition by valproic acid and other inhibitors upregulates fibroblast growth factor 21 expression and, if so, sought to identify the histone deacetylase isoform(s) involved and their role in altering glial cell morphology. Methods: C6 glioma or primary cortical glial cultures were treated with histone deacetylase inhibitors, and fibroblast growth factor 21 levels and length of cell processes were subsequently measured. Histone deacetylase 1, 2, or 3 was also knocked down to detect which isoform was involved in regulating fibroblast growth factor 21 mRNA levels. Finally, knockdown and overexpression of fibroblast growth factor 21 were performed to determine whether it played a role in regulating cell process length. Results: Treatment of C6 cells or primary glial cultures with valproic acid elevated fibroblast growth factor 21 mRNA levels, extended cell process length, and markedly increased acetylated histone-H3 levels. Other histone deacetylase inhibitors including pan- and class I-specific inhibitors, or selective knockdown of histone deacetylase 2 or 3 isoform produced similar effects. Knockdown or overexpression of fibroblast growth factor 21 significantly decreased or increased C6 cell process length, respectively. Conclusions: In glial cell line and primary glia, using pharmacological inhibition and selective gene silencing of histone deacetylases to boost fibroblast growth factor 21 mRNA levels results in elongation of cell processes. Our study provides a new mechanism via which histone deacetylase 2 and 3 participate in upregulating fibroblast growth factor 21 transcription and extending process outgrowth

  6. Discovery of HDAC Inhibitors with Potent Activity Against Multiple Malaria Parasite Life Cycle Stages

    PubMed Central

    Hansen, Finn K.; Sumanadasa, Subathdrage D. M.; Stenzel, Katharina; Duffy, Sandra; Meister, Stephan; Marek, Linda; Schmetter, Rebekka; Kuna, Krystina; Hamacher, Alexandra; Mordmüller, Benjamin; Kassack, Matthias U.; Winzeler, Elizabeth A.; Avery, Vicky M.; Andrews, Katherine T.; Kurz, Thomas

    2015-01-01

    In this work we investigated the antiplasmodial activity of a series of HDAC inhibitors containing an alkoxyamide connecting-unit linker region. HDAC inhibitor 1a (LMK235), previously shown to be a novel and specific inhibitor of human HDAC4 and 5, was used as a starting point to rapidly construct a mini-library of HDAC inhibitors using a straightforward solid-phase supported synthesis. Several of these novel HDAC inhibitors were found to have potent in vitro activity against asexual stage P. falciparum malaria parasites. Representative compounds were shown to hyperacetylate P. falciparum histones and to inhibit deacetylase activity of recombinant PfHDAC1 and P. falciparum nuclear extracts. All compounds were also screened in vitro for activity against P. berghei exo-erythrocytic stages and selected compounds were further tested against late stage (IV and V) P. falciparum gametocytes. Of note, some compounds showed nanomolar activity against all three life cycle stages tested (asexual, exo-erythrocytic and gametocyte stages) and several compounds displayed significantly increased parasite selectivity compared to the reference HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). These data suggest that it may be possible to develop HDAC inhibitors that target multiple malaria parasite life cycle stages. PMID:24904967

  7. Potent, Selective, and CNS-Penetrant Tetrasubstituted Cyclopropane Class IIa Histone Deacetylase (HDAC) Inhibitors

    PubMed Central

    2015-01-01

    Potent and selective class IIa HDAC tetrasubstituted cyclopropane hydroxamic acid inhibitors were identified with high oral bioavailability that exhibited good brain and muscle exposure. Compound 14 displayed suitable properties for assessment of the impact of class IIa HDAC catalytic site inhibition in preclinical disease models. PMID:26819662

  8. Molecular dynamics simulation of complex Histones Deacetylase (HDAC) Class II Homo Sapiens with suberoylanilide hydroxamic acid (SAHA) and its derivatives as inhibitors of cervical cancer.

    PubMed

    Tambunan, Usman Sumo Friend; Bakri, Ridla; Prasetia, Tirtana; Parikesit, Arli Aditya; Kerami, Djati

    2013-01-01

    Cervical cancer is second most common cancer in woman worldwide. Cervical cancer caused by human papillomavirus (HPV) oncogene. Inhibition of histone deacetylase (HDAC) activity has been known as a potential strategy for cancer therapy. SAHA is an HDAC inhibitor that has been used in cancer therapy but still has side effects. SAHA modification proposed to minimize side effects. Triazole attachment on the chain of SAHA has been known to enhance the inhibition ability of SAHA and less toxic. In this study, it will be carried out with molecular dynamic simulations of SAHA modifications consisting ligand 1a, 2a and, 2c to interact with six HDAC in hydrated conditions. To all six HDAC Class II, performed docking with SAHA and a modified inhibitor. The docking results were then carried out molecular dynamics simulations to determine the inhibitor affinities in hydrated conditions. The molecular dynamic simulations results show better affinities of ligand 2c with HDAC 4, 6, and 7 than SAHA itself, and good affinity was also shown by ligand 2a and 1c on HDAC 5 and 9. The results of this study can be a reference to obtain better inhibitors.

  9. Induction of histone deacetylases (HDACs) in human abdominal aortic aneurysm: therapeutic potential of HDAC inhibitors

    PubMed Central

    Galán, María; Varona, Saray; Orriols, Mar; Rodríguez, José Antonio; Aguiló, Silvia; Dilmé, Jaume; Camacho, Mercedes; Martínez-González, José; Rodriguez, Cristina

    2016-01-01

    ABSTRACT Clinical management of abdominal aortic aneurysm (AAA) is currently limited to elective surgical repair because an effective pharmacotherapy is still awaited. Inhibition of histone deacetylase (HDAC) activity could be a promising therapeutic option in cardiovascular diseases. We aimed to characterise HDAC expression in human AAA and to evaluate the therapeutic potential of class I and IIa HDAC inhibitors in the AAA model of angiotensin II (Ang II)-infused apolipoprotein-E-deficient (ApoE−/−) mice. Real-time PCR, western blot and immunohistochemistry evidenced an increased expression of HDACs 1, 2 (both class I), 4 and 7 (both class IIa) in abdominal aorta samples from patients undergoing AAA open repair (n=22) compared with those from donors (n=14). Aortic aneurysms from Ang-II-infused ApoE−/− mice exhibited a similar HDAC expression profile. In these animals, treatment with a class I HDAC inhibitor (MS-275) or a class IIa inhibitor (MC-1568) improved survival, reduced the incidence and severity of AAA and limited aneurysmal expansion evaluated by Doppler ultrasonography. These beneficial effects were more potent in MC-1568-treated mice. The disorganisation of elastin and collagen fibres and lymphocyte and macrophage infiltration were effectively reduced by both inhibitors. Additionally, HDAC inhibition attenuated the exacerbated expression of pro-inflammatory markers and the increase in metalloproteinase-2 and -9 activity induced by Ang II in this model. Therefore, our data evidence that HDAC expression is deregulated in human AAA and that class-selective HDAC inhibitors limit aneurysm expansion in an AAA mouse model. New-generation HDAC inhibitors represent a promising therapeutic approach to overcome human aneurysm progression. PMID:26989193

  10. Induction of histone deacetylases (HDACs) in human abdominal aortic aneurysm: therapeutic potential of HDAC inhibitors.

    PubMed

    Galán, María; Varona, Saray; Orriols, Mar; Rodríguez, José Antonio; Aguiló, Silvia; Dilmé, Jaume; Camacho, Mercedes; Martínez-González, José; Rodriguez, Cristina

    2016-05-01

    Clinical management of abdominal aortic aneurysm (AAA) is currently limited to elective surgical repair because an effective pharmacotherapy is still awaited. Inhibition of histone deacetylase (HDAC) activity could be a promising therapeutic option in cardiovascular diseases. We aimed to characterise HDAC expression in human AAA and to evaluate the therapeutic potential of class I and IIa HDAC inhibitors in the AAA model of angiotensin II (Ang II)-infused apolipoprotein-E-deficient (ApoE(-/-)) mice. Real-time PCR, western blot and immunohistochemistry evidenced an increased expression of HDACs 1, 2 (both class I), 4 and 7 (both class IIa) in abdominal aorta samples from patients undergoing AAA open repair (n=22) compared with those from donors (n=14). Aortic aneurysms from Ang-II-infused ApoE(-/-) mice exhibited a similar HDAC expression profile. In these animals, treatment with a class I HDAC inhibitor (MS-275) or a class IIa inhibitor (MC-1568) improved survival, reduced the incidence and severity of AAA and limited aneurysmal expansion evaluated by Doppler ultrasonography. These beneficial effects were more potent in MC-1568-treated mice. The disorganisation of elastin and collagen fibres and lymphocyte and macrophage infiltration were effectively reduced by both inhibitors. Additionally, HDAC inhibition attenuated the exacerbated expression of pro-inflammatory markers and the increase in metalloproteinase-2 and -9 activity induced by Ang II in this model. Therefore, our data evidence that HDAC expression is deregulated in human AAA and that class-selective HDAC inhibitors limit aneurysm expansion in an AAA mouse model. New-generation HDAC inhibitors represent a promising therapeutic approach to overcome human aneurysm progression. © 2016. Published by The Company of Biologists Ltd.

  11. Development of N-hydroxycinnamamide-based HDAC inhibitors with improved HDAC inhibitory activity and in vitro antitumor activity.

    PubMed

    Zang, Jie; Shi, Baowen; Liang, Xuewu; Gao, Qianwen; Xu, Wenfang; Zhang, Yingjie

    2017-05-01

    Histone deacetylase inhibitors (HDACIs) are promising in the treatment of various diseases, among which cancer treatment has achieved the most success. We have previously developed series of HDACIs combining N-hydroxycinnamamide bioactive fragment and indole bioactive fragment, which showed moderate to potent antitumor activities. Herein, further structural derivatization based on our previous structure-activity relationship (SAR) got 25 novel compounds. Most compounds showed much more potent histone deacetylases (HDACs) inhibitory activity than their parent compound 1 and even the positive control SAHA. What's more, compared with the approved HDACs inhibitor SAHA, compounds 6i, 6k, 6q and 6t displayed better in vitro antiproliferation against multiple tumor cell lines. It is worth noting that though the 4-hydroxycinnamic acid-based compound 2 showed HDAC1/3 dual selectivity, its 4-hydroxy-3-methoxycinnamic acid-based analog 6t turned out to be a pan-HDACs inhibitor as SAHA, indicating that the 3-methoxy group on the N-hydroxycinnamamide fragment could dramatically influence the HDACs isoform selectivity of this series of compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Synergistic Interactions between HDAC and Sirtuin Inhibitors in Human Leukemia Cells

    PubMed Central

    Cea, Michele; Soncini, Debora; Fruscione, Floriana; Raffaghello, Lizzia; Garuti, Anna; Emionite, Laura; Moran, Eva; Magnone, Mirko; Zoppoli, Gabriele; Reverberi, Daniele; Caffa, Irene; Salis, Annalisa; Cagnetta, Antonia; Bergamaschi, Micaela; Casciaro, Salvatore; Pierri, Ivana; Damonte, Gianluca; Ansaldi, Filippo; Gobbi, Marco; Pistoia, Vito; Ballestrero, Alberto; Patrone, Franco

    2011-01-01

    Aberrant histone deacetylase (HDAC) activity is frequent in human leukemias. However, while classical, NAD+-independent HDACs are an established therapeutic target, the relevance of NAD+-dependent HDACs (sirtuins) in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD+-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527) and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD+ levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD+-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited. PMID:21818379

  13. Histone Deacetylase Inhibitor Phenylbutyrate Exaggerates Heart Failure in Pressure Overloaded Mice independently of HDAC inhibition

    PubMed Central

    Ma, Jing; Luo, Tao; Zeng, Zhi; Fu, Haiying; Asano, Yoshihiro; Liao, Yulin; Minamino, Tetsuo; Kitakaze, Masafumi

    2016-01-01

    4-Sodium phenylbutyrate (PBA) has been reported to inhibit endoplasmic reticulum stress and histone deacetylation (HDAC), both of which are novel therapeutic targets for cardiac hypertrophy and heart failure. However, it is unclear whether PBA can improve heart function. Here, we tested the effects of PBA and some other HDAC inhibitors on cardiac dysfunction induced by pressure overload. Transverse aortic constriction (TAC) was performed on male C57BL/6 mice. PBA treatment (100 mg/kg, 6 weeks) unexpectedly led to a higher mortality, exacerbated cardiac remodelling and dysfunction. Similar results were noted in TAC mice treated with butyrate sodium (BS), a PBA analogue. In contrast, other HDAC inhibitors, valproic acid (VAL) and trichostatin A (TSA), improved the survival. All four HDAC inhibitors induced histone H3 acetylation and inhibited HDAC total activity. An individual HDAC activity assay showed that rather than class IIa members (HDAC4 and 7), PBA and BS predominantly inhibited class I members (HDAC2 and 8), whereas VAL and TSA inhibited all of them. These findings indicate that PBA and BS accelerate cardiac hypertrophy and dysfunction, whereas VAL and TSA have opposing effects. PMID:27667442

  14. Roles of HDAC2 and HDAC8 in Cardiac Remodeling in Renovascular Hypertensive Rats and the Effects of Valproic Acid Sodium.

    PubMed

    Li, Rui-Fang; Cao, Shan-Shan; Fang, Wei-Jin; Song, Ying; Luo, Xue-Ting; Wang, Hong-Yun; Wang, Jian-Gang

    2017-01-01

    Recent studies indicate that histone deacetylases (HDACs) activity is associated with the development and progression of cardiac hypertrophy. In this study, we investigated the effects of a HDACs inhibitor, valproic acid sodium (VPA), on cardiac remodeling and the differential expression of HDACs in left ventricles (LVs) of renovascular hypertensive rats. Renovascular hypertension was induced in rats by the two-kidney two-clip (2K2C) method. Cardiac remodeling, heart function and the differential expression of HDACs were examined at different weeks after 2K2C operation. The effects of VPA on cardiac remodeling, the expressions of HDACs, transforming growth factor-beta 1 (TGF-β1) and connective tissue growth factor (CTGF) in LV were investigated. The expressions of atrial natriuretic factor, β-myosin heavy chain, HDAC2 and HDAC8 increased in LV of 2K2C rats at 4, 8, 12 weeks after operation. Cardiac dysfunction, cardiac hypertrophy and fibrosis were markedly attenuated by VPA treatment in 2K2C rats. Further studies revealed that VPA inhibited the expressions of HDAC2, HDAC8, TGF-β1 and CTGF in LV of 2K2C rats. In summary, these data indicate that HDAC2 and HDAC8 play a key role in cardiac remodeling in renovascular hypertensive rats and that VPA attenuates hypertension and cardiac remodeling. The effect of VPA is possibly exerted via decreasing HDAC2, HDAC8, TGF-β1 and CTGF expressions in LV of 2K2C rats.

  15. Development and validation of high-performance liquid chromatography-tandem mass spectrometry assay for 6-(3-benzoyl-ureido)-hexanoic acid hydroxyamide, a novel HDAC inhibitor, in mouse plasma for pharmacokinetic studies.

    PubMed

    Yeo, Pauline; Xin, Liu; Goh, Evelyn; New, Lee Sun; Zeng, Peizi; Wu, Xiaofeng; Venkatesh, P; Kantharaj, Ethirajulu

    2007-02-01

    A liquid chromatography/tandem mass spectrometric method for the quantification of 6-(3-benzoyl-ureido)-hexanoic acid hydroxyamide (EX-2), a novel histone deacetylase (HDAC) inhibitor, in mouse plasma was developed to support in-house pharmacokinetic (PK) studies in the lead optimization stage. In order to determine the PK parameters for EX-2 in comparison to other HDAC inhibitors such as suberoylanilide hydroxamic acid (SAHA), PXD-101 and LBH-589, which are currently in different stages of clinical trials, research-grade bio-analytical method validations were carried out for EX-2 and these reference HDAC inhibitors, which were synthesized by in-house medicinal chemists. The components of validation consisted of specificity, extraction efficiency, signal-response of calibration standards, lower limit of quantification, autosampler stability and accuracy and precision of quality control samples. The validated LC/MS/MS methods were accurate and precise. The calibration curve ranged from 1 to 1600 ng/mL for all the analytes. The methods developed were used to quantify EX-2 and other HDAC inhibitors in mouse plasma obtained from pharmacokinetic studies. The results suggest that EX-2 has better PK parameters compared with the reference drugs and is a promising drug development candidate. Copyright 2007 John Wiley & Sons, Ltd.

  16. HDAC inhibitors and immunotherapy; a double edged sword?

    PubMed

    Kroesen, Michiel; Gielen, Paul; Brok, Ingrid C; Armandari, Inna; Hoogerbrugge, Peter M; Adema, Gosse J

    2014-08-30

    Epigenetic modifications, like histone acetylation, are essential for regulating gene expression within cells. Cancer cells acquire pathological epigenetic modifications resulting in gene expression patterns that facilitate and sustain tumorigenesis. Epigenetic manipulation therefore is emerging as a novel targeted therapy for cancer. Histone Acetylases (HATs) and Histone Deacetylases (HDACs) regulate histone acetylation and hence gene expression. Histone deacetylase (HDAC) inhibitors are well known to affect cancer cell viability and biology and are already in use for the treatment of cancer patients. Immunotherapy can lead to clinical benefit in selected cancer patients, especially in patients with limited disease after tumor debulking. HDAC inhibitors can potentially synergize with immunotherapy by elimination of tumor cells. The direct effects of HDAC inhibitors on immune cell function, however, remain largely unexplored. Initial data have suggested HDAC inhibitors to be predominantly immunosuppressive, but more recent reports have challenged this view. In this review we will discuss the effects of HDAC inhibitors on tumor cells and different immune cell subsets, synergistic interactions and possible mechanisms. Finally, we will address future challenges and potential application of HDAC inhibitors in immunocombination therapy of cancer.

  17. HDAC inhibitors and immunotherapy; a double edged sword?

    PubMed Central

    Kroesen, Michiel; Armandari, Inna; Hoogerbrugge, Peter M.; Adema, Gosse J.

    2014-01-01

    Epigenetic modifications, like histone acetylation, are essential for regulating gene expression within cells. Cancer cells acquire pathological epigenetic modifications resulting in gene expression patterns that facilitate and sustain tumorigenesis. Epigenetic manipulation therefore is emerging as a novel targeted therapy for cancer. Histone Acetylases (HATs) and Histone Deacetylases (HDACs) regulate histone acetylation and hence gene expression. Histone deacetylase (HDAC) inhibitors are well known to affect cancer cell viability and biology and are already in use for the treatment of cancer patients. Immunotherapy can lead to clinical benefit in selected cancer patients, especially in patients with limited disease after tumor debulking. HDAC inhibitors can potentially synergize with immunotherapy by elimination of tumor cells. The direct effects of HDAC inhibitors on immune cell function, however, remain largely unexplored. Initial data have suggested HDAC inhibitors to be predominantly immunosuppressive, but more recent reports have challenged this view. In this review we will discuss the effects of HDAC inhibitors on tumor cells and different immune cell subsets, synergistic interactions and possible mechanisms. Finally, we will address future challenges and potential application of HDAC inhibitors in immunocombination therapy of cancer. PMID:25115382

  18. Synthesis of a selective HDAC6 inhibitor active in neuroblasts.

    PubMed

    Zwick, Vincent; Simões-Pires, Claudia A; Nurisso, Alessandra; Petit, Charlotte; Dos Santos Passos, Carolina; Randazzo, Giuseppe Marco; Martinet, Nadine; Bertrand, Philippe; Cuendet, Muriel

    2016-10-15

    In recent years, the role of HDAC6 in neurodegeneration has been partially elucidated, which led some authors to propose HDAC6 inhibitors as a therapeutic strategy to treat neurodegenerative diseases. In an effort to develop a selective HDAC6 inhibitor which can cross the blood brain barrier (BBB), a modified hydroxamate derivative (compound 3) was designed and synthetized. This compound was predicted to have potential for BBB penetration based on in silico and in vitro evaluation of passive permeability. When tested for its HDAC inhibitory activity, the IC50 value of compound 3 towards HDAC6 was in the nM range in both enzymatic and cell-based assays. Compound 3 showed a cell-based selectivity profile close to that of tubastatin A in SH-SY5Y human neuroblastoma cells, and a good BBB permeability profile.

  19. Synthesis and Biological Investigation of Oxazole Hydroxamates as Highly Selective Histone Deacetylase 6 (HDAC6) Inhibitors.

    PubMed

    Senger, Johanna; Melesina, Jelena; Marek, Martin; Romier, Christophe; Oehme, Ina; Witt, Olaf; Sippl, Wolfgang; Jung, Manfred

    2016-02-25

    Histone deacetylase 6 (HDAC6) catalyzes the removal of an acetyl group from lysine residues of several non-histone proteins. Here we report the preparation of thiazole-, oxazole-, and oxadiazole-containing biarylhydroxamic acids by a short synthetic procedure. We identified them as selective HDAC6 inhibitors by investigating the inhibition of recombinant HDAC enzymes and the protein acetylation in cells by Western blotting (tubulin vs histone acetylation). The most active compounds exhibited nanomolar potency and high selectivity for HDAC6. For example, an oxazole hydroxamate inhibits HDAC6 with an IC50 of 59 nM and has a selectivity index of >200 against HDAC1 and HDAC8. This is the first report showing that the nature of a heterocycle directly connected to a zinc binding group (ZBG) can be used to modulate subtype selectivity and potency for HDAC6 inhibitors to such an extent. We rationalize the high potency and selectivity of the oxazoles by molecular modeling and docking.

  20. New and emerging HDAC inhibitors for cancer treatment

    PubMed Central

    West, Alison C.; Johnstone, Ricky W.

    2014-01-01

    Epigenetic enzymes are often dysregulated in human tumors through mutation, altered expression, or inappropriate recruitment to certain loci. The identification of these enzymes and their partner proteins has driven the rapid development of small-molecule inhibitors that target the cancer epigenome. Herein, we discuss the influence of aberrantly regulated histone deacetylases (HDACs) in tumorigenesis. We examine HDAC inhibitors (HDACis) targeting class I, II, and IV HDACs that are currently under development for use as anticancer agents following the FDA approval of two HDACis, vorinostat and romidepsin. PMID:24382387

  1. Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by PET

    PubMed Central

    Kim, Sung Won; Hooker, Jacob M.; Otto, Nicola; Win, Khaing; Muench, Lisa; Shea, Colleen; Carter, Pauline; King, Payton; Reid, Alicia E.; Volkow, Nora D.; Fowler, Joanna S.

    2013-01-01

    The fatty acids, n-butyric acid (BA), 4-phenylbutyric acid (PBA) and valproic acid (VPA, 2-propylpentanoic acid) have been used for many years in the treatment of a variety of CNS and peripheral organ diseases including cancer. New information that these drugs alter epigenetic processes through their inhibition of histone deacetylases (HDACs) has renewed interest in their biodistribution and pharmacokinetics and the relationship of these properties to their therapeutic and side effect profile. In order to determine the pharmacokinetics and biodistribution of these drugs in primates, we synthesized their carbon-11 labeled analogues and performed dynamic positron emission tomography (PET) in six female baboons over 90 min. The carbon-11 labeled carboxylic acids were prepared by using 11CO2 and the appropriate Grignard reagents. [11C]BA was metabolized rapidly (only 20% of the total carbon-11 in plasma was parent compound at 5 min post injection) whereas for VPA and PBA 98% and 85% of the radioactivity was the unmetabolized compound at 30 min after their administration respectively. The brain uptake of all three carboxylic acids was very low (<0.006%ID/cc, BA>VPA>PBA), which is consistent with the need for very high doses for therapeutic efficacy. Most of the radioactivity was excreted through the kidneys and accumulated in the bladder. However, the organ biodistribution between the drugs differed. [11C]BA showed relatively high uptake in spleen and pancreas whereas [11C]PBA showed high uptake in liver and heart. Notably, [11C]VPA showed exceptionally high heart uptake possibly due to its involvement in lipid metabolism. The unique biodistribution of each of these drugs may be of relevance in understanding their therapeutic and side effect profile including their teratogenic effects. PMID:23906667

  2. Identification of HDAC Inhibitors with Benzoylhydrazide scaffold that Selectively Inhibit Class I HDACs

    PubMed Central

    Wang, Yunfei; Stowe, Ryan L.; Pinello, Christie E.; Tian, Guimei; Madoux, Franck; Li, Dawei; Zhao, Lisa Y.; Li, Jian-Liang; Wang, Yuren; Wang, Yuan; Ma, Haiching; Hodder, Peter; Roush, William R.; Liao, Daiqing

    2015-01-01

    SUMMARY Inhibitors of histone deacetylases (HDACi) hold a considerable therapeutic promise as clinical anticancer therapies. However, currently known HDACi exhibit limited isoform specificity, off-target activity, and undesirable pharmaceutical properties. Thus, HDACi with new chemotypes are needed to overcome these limitations. Here, we identify a class of HDACi with a previously undescribed benzoylhydrazide scaffold that is selective for the class I HDACs. These compounds are competitive inhibitors with a fast-on/slow-off HDAC-binding mechanism. We show that the lead compound, UF010, inhibits cancer cell proliferation via class I HDAC inhibition. This causes global changes in protein acetylation and gene expression resulting in activation of tumor suppressor pathways and concurrent inhibition of several oncogenic pathways. The isotype selectivity coupled with interesting biological activities in suppressing tumor cell proliferation support further preclinical development of the UF010 class of compounds for potential therapeutic applications. PMID:25699604

  3. The HDAC inhibitors trichostatin A and suberoylanilide hydroxamic acid exhibit multiple modalities of benefit for the vascular pathobiology of sickle transgenic mice

    PubMed Central

    Vercellotti, Gregory M.; Pace, Betty S.; Solovey, Anna N.; Kollander, Rahn; Abanonu, Chine F.; Nguyen, Julia; Vineyard, Julie V.; Belcher, John D.; Abdulla, Fuad; Osifuye, Shadé; Eaton, John W.; Kelm, Robert J.; Slungaard, Arne

    2010-01-01

    The vascular pathobiology of sickle cell anemia involves inflammation, coagulation, vascular stasis, reperfusion injury, iron-based oxidative biochemistry, deficient nitric oxide (NO) bioavailability, and red cell sickling. These disparate pathobiologies intersect and overlap, so it is probable that multimodality therapy will be necessary for this disease. We have, therefore, tested a histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), for efficacy in reducing endothelial activation. We found that pulmonary vascular endothelial VCAM-1 and tissue factor (TF) expression (both are indicators of endothelial activation) are powerfully and significantly inhibited by TSA. This is seen both with pretreatment before the inducing stress of hypoxia/reoxygenation (NY1DD sickle transgenic mouse), and upon longer-term therapy after endothelial activation has already occurred (hBERK1 sickle mouse at ambient air). In addition, TSA prevented vascular stasis in sickle mice, it exhibited activity as an iron chelator, and it induced expression of the antisickling hemoglobin, hemoglobin F. Notably, the TSA analog SAHA (suberoylanilide hydroxaminc acid) that is already approved for human clinical use exhibits the same spectrum of biologic effects as TSA. We suggest that SAHA possibly could provide true, multimodality, salubrious effects for prevention and treatment of the chronic vasculopathy of sickle cell anemia. PMID:20053759

  4. The HDAC inhibitors trichostatin A and suberoylanilide hydroxamic acid exhibit multiple modalities of benefit for the vascular pathobiology of sickle transgenic mice.

    PubMed

    Hebbel, Robert P; Vercellotti, Gregory M; Pace, Betty S; Solovey, Anna N; Kollander, Rahn; Abanonu, Chine F; Nguyen, Julia; Vineyard, Julie V; Belcher, John D; Abdulla, Fuad; Osifuye, Shadé; Eaton, John W; Kelm, Robert J; Slungaard, Arne

    2010-03-25

    The vascular pathobiology of sickle cell anemia involves inflammation, coagulation, vascular stasis, reperfusion injury, iron-based oxidative biochemistry, deficient nitric oxide (NO) bioavailability, and red cell sickling. These disparate pathobiologies intersect and overlap, so it is probable that multimodality therapy will be necessary for this disease. We have, therefore, tested a histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), for efficacy in reducing endothelial activation. We found that pulmonary vascular endothelial VCAM-1 and tissue factor (TF) expression (both are indicators of endothelial activation) are powerfully and significantly inhibited by TSA. This is seen both with pretreatment before the inducing stress of hypoxia/reoxygenation (NY1DD sickle transgenic mouse), and upon longer-term therapy after endothelial activation has already occurred (hBERK1 sickle mouse at ambient air). In addition, TSA prevented vascular stasis in sickle mice, it exhibited activity as an iron chelator, and it induced expression of the antisickling hemoglobin, hemoglobin F. Notably, the TSA analog SAHA (suberoylanilide hydroxaminc acid) that is already approved for human clinical use exhibits the same spectrum of biologic effects as TSA. We suggest that SAHA possibly could provide true, multimodality, salubrious effects for prevention and treatment of the chronic vasculopathy of sickle cell anemia.

  5. HDAC inhibitors: modulating leukocyte differentiation, survival, proliferation and inflammation.

    PubMed

    Sweet, Matthew J; Shakespear, Melanie R; Kamal, Nabilah A; Fairlie, David P

    2012-01-01

    Therapeutic effects of histone deacetylase (HDAC) inhibitors in cancer models were first linked to their ability to cause growth arrest and apoptosis of tumor cells. It is now clear that these agents also have pleiotropic effects on angiogenesis and the immune system, and some of these properties are likely to contribute to their anti-cancer activities. It is also emerging that inhibitors of specific HDACs affect the differentiation, survival and/or proliferation of distinct immune cell populations. This is true for innate immune cells such as macrophages, as well as cells of the acquired immune system, for example, T-regulatory cells. These effects may contribute to therapeutic profiles in some autoimmune and chronic inflammatory disease models. Here, we review our current understanding of how classical HDACs (HDACs 1-11) and their inhibitors impact on differentiation, survival and proliferation of distinct leukocyte populations, as well as the likely relevance of these effects to autoimmune and inflammatory disease processes. The ability of HDAC inhibitors to modulate leukocyte survival may have implications for the rationale of developing selective inhibitors as anti-inflammatory drugs.

  6. Isoxazole moiety in the linker region of HDAC inhibitors adjacent to the Zn-chelating group: effects on HDAC biology and antiproliferative activity.

    PubMed

    Tapadar, Subhasish; He, Rong; Luchini, Doris N; Billadeau, Daniel D; Kozikowski, Alan P

    2009-06-01

    A series of hydroxamic acid based histone deacetylase inhibitors 6-15, containing an isoxazole moiety adjacent to the Zn-chelating hydroxamic acid, is reported herein. Some of these compounds showed nanomolar activity in the HDAC isoform inhibitory assay and exhibited micro molar inhibitory activity against five pancreatic cancer cell lines.

  7. Combining HDAC inhibitors with oncolytic virotherapy for cancer therapy.

    PubMed

    Nakashima, Hiroshi; Nguyen, Tran; Chiocca, Ennio Antonio

    2015-01-01

    Histone deacetylase (HDAC) enzymes play a critical role in the epigenetic regulation of cellular functions and signaling pathways in many cancers. HDAC inhibitors (HDACi) have been validated for single use or in combination with other drugs in oncologic therapeutics. An even more novel combination therapy with HDACi is to use them with an oncolytic virus. HDACi may lead to an amplification of tumor-specific lytic effects by facilitating increased cycles of viral replication, but there may also be direct anticancer effects of the drug by itself. Here, we review the molecular mechanisms of anti-cancer effects of the combination of oncolytic viruses with HDACi.

  8. In Vivo Screening Using Transgenic Zebrafish Embryos Reveals New Effects of HDAC Inhibitors Trichostatin A and Valproic Acid on Organogenesis

    PubMed Central

    Li, Ling; Bonneton, François; Tohme, Marie; Bernard, Laure; Chen, Xiao Yong; Laudet, Vincent

    2016-01-01

    The effects of endocrine disrupting chemicals (EDCs) on reproduction are well known, whereas their developmental effects are much less characterized. However, exposure to endocrine disruptors during organogenesis may lead to deleterious and permanent problems later in life. Zebrafish (Danio rerio) transgenic lines expressing the green fluorescent protein (GFP) in specific organs and tissues are powerful tools to uncover developmental defects elicited by EDCs. Here, we used seven transgenic lines to visualize in vivo whether a series of EDCs and other pharmaceutical compounds can alter organogenesis in zebrafish. We used transgenic lines expressing GFP in pancreas, liver, blood vessels, inner ear, nervous system, pharyngeal tooth and pectoral fins. This screen revealed that four of the tested chemicals have detectable effects on different organs, which shows that the range of effects elicited by EDCs is wider than anticipated. The endocrine disruptor tetrabromobisphenol-A (TBBPA), as well as the three drugs diclofenac, trichostatin A (TSA) and valproic acid (VPA) induced abnormalities in the embryonic vascular system of zebrafish. Moreover, TSA and VPA induced specific alterations during the development of pancreas, an observation that was confirmed by in situ hybridization with specific markers. Developmental delays were also induced by TSA and VPA in the liver and in pharyngeal teeth, resulting in smaller organ size. Our results show that EDCs can induce a large range of developmental alterations during embryogenesis of zebrafish and establish GFP transgenic lines as powerful tools to screen for EDCs effects in vivo. PMID:26900852

  9. HDAC inhibitors as cognitive enhancers in fear, anxiety and trauma therapy: where do we stand?

    PubMed Central

    Whittle, Nigel; Singewald, Nicolas

    2014-01-01

    A novel strategy to treat anxiety and fear-related disorders such as phobias, panic and PTSD (post-traumatic stress disorder) is combining CBT (cognitive behavioural therapy), including extinction-based exposure therapy, with cognitive enhancers. By targeting and boosting mechanisms underlying learning, drug development in this field aims at designing CBT-augmenting compounds that help to overcome extinction learning deficits, promote long-term fear inhibition and thus support relapse prevention. Progress in revealing the role of epigenetic regulation of specific genes associated with extinction memory generation has opened new avenues in this direction. The present review examines recent evidence from pre-clinical studies showing that increasing histone acetylation, either via genetic or pharmacological inhibition of HDACs (histone deacetylases) by e.g. vorinostat/SAHA (suberoylanilide hydroxamic acid), entinostat/MS-275, sodium butyrate, TSA (trichostatin A) or VPA (valproic acid), or by targeting HATs (histone acetyltransferases), augments fear extinction and, importantly, generates a long-term extinction memory that can protect from return of fear phenomena. The molecular mechanisms and pathways involved including BDNF (brain-derived neurotrophic factor) and NMDA (N-methyl-D-aspartate) receptor signalling are just beginning to be revealed. First studies in healthy humans are in support of extinction-facilitating effects of HDAC inhibitors. Very recent evidence that HDAC inhibitors can rescue deficits in extinction-memory-impaired rodents indicates a potential clinical utility of this approach also for exposure therapy-resistant patients. Important future work includes investigation of the long-term safety aspects of HDAC inhibitor treatment, as well as design of isotype(s)-specific inhibitors. Taken together, HDAC inhibitors display promising potential as pharmacological adjuncts to augment the efficacy of exposure-based approaches in anxiety and trauma therapy

  10. Increased expression of histone deacetylaces (HDACs) and inhibition of prostate cancer growth and invasion by HDAC inhibitor SAHA

    PubMed Central

    Wang, Longgui; Zou, Xuanyi; Berger, Aaron D.; Twiss, Christian; Peng, Yi; Li, Yirong; Chiu, Jason; Guo, Hongfeng; Satagopan, Jaya; Wilton, Andrew; Gerald, William; Basch, Ross; Wang, Zhengxin; Osman, Iman; Lee, Peng

    2009-01-01

    Histone deacetetylases (HDACs) are a group of corepressors of transcriptional activators and their levels of expression are potentially dysregulated in prostate cancer. Certain inhibitors of histone deacetylases show anti-tumor activity in prostate cancer cell lines. Here, we systemically studied the expression of HDACs in human prostate cancer and the suppression of prostate cancer growth and invasion by HDAC inhibitor SAHA. HDAC1-5 showed increased expression using a combination of DNA microarray, in-situ hybridization, and immunohistochemistry in benign and malignant human prostate tissue as well as RT-PCR and Western blot analysis on various PCa cell lines. Importantly, HDAC inhibitor SAHA suppressed, in particular, prostate cancer cell growth and invasion determined using cell proliferation and Matrigel invasion assays. The findings of this study show that the expression of HDACs and their associated corepressors are increased in prostate cancer in humans and HDAC inhibitor SAHA could serve as a potential therapeutic agent in prostate cancer in addition to anti-androgens. PMID:19966939

  11. Oral Administration of the Pimelic Diphenylamide HDAC Inhibitor HDACi 4b Is Unsuitable for Chronic Inhibition of HDAC Activity in the CNS In Vivo

    PubMed Central

    Beconi, Maria; Aziz, Omar; Matthews, Kim; Moumné, Lara; O’Connell, Catherine; Yates, Dawn; Clifton, Steven; Pett, Hannah; Vann, Julie; Crowley, Lynsey; Haughan, Alan F.; Smith, Donna L.; Woodman, Ben; Bates, Gillian P.; Brookfield, Fred; Bürli, Roland W.; McAllister, George; Dominguez, Celia; Munoz-Sanjuan, Ignacio; Beaumont, Vahri

    2012-01-01

    Histone deacetylase (HDAC) inhibitors have received considerable attention as potential therapeutics for a variety of cancers and neurological disorders. Recent publications on a class of pimelic diphenylamide HDAC inhibitors have highlighted their promise in the treatment of the neurodegenerative diseases Friedreich’s ataxia and Huntington’s disease, based on efficacy in cell and mouse models. These studies’ authors have proposed that the unique action of these compounds compared to hydroxamic acid-based HDAC inhibitors results from their unusual slow-on/slow-off kinetics of binding, preferentially to HDAC3, resulting in a distinctive pharmacological profile and reduced toxicity. Here, we evaluate the HDAC subtype selectivity, cellular activity, absorption, distribution, metabolism and excretion (ADME) properties, as well as the central pharmacodynamic profile of one such compound, HDACi 4b, previously described to show efficacy in vivo in the R6/2 mouse model of Huntington’s disease. Based on our data reported here, we conclude that while the in vitro selectivity and binding mode are largely in agreement with previous reports, the physicochemical properties, metabolic and p-glycoprotein (Pgp) substrate liability of HDACi 4b render this compound suboptimal to investigate central Class I HDAC inhibition in vivo in mouse per oral administration. A drug administration regimen using HDACi 4b dissolved in drinking water was used in the previous proof of concept study, casting doubt on the validation of CNS HDAC3 inhibition as a target for the treatment of Huntington’s disease. We highlight physicochemical stability and metabolic issues with 4b that are likely intrinsic liabilities of the benzamide chemotype in general. PMID:22973455

  12. Design, synthesis and biological evaluation of bisthiazole-based trifluoromethyl ketone derivatives as potent HDAC inhibitors with improved cellular efficacy.

    PubMed

    Gong, Chao-Jun; Gao, An-Hui; Zhang, Yang-Ming; Su, Ming-Bo; Chen, Fei; Sheng, Li; Zhou, Yu-Bo; Li, Jing-Ya; Li, Jia; Nan, Fa-Jun

    2016-04-13

    Histone deacetylases (HDACs) are a class of epigenetic modulators with complex functions in histone post-translational modifications and are well known targets for antineoplastic drugs. We have previously developed a series of bisthiazole-based hydroxamic acids as novel potent HDAC inhibitors. In the present work, a new series of bisthiazole-based compounds with different zinc binding groups (ZBGs) have been designed and synthesized. Among them is compound 7, containing a trifluoromethyl ketone as the ZBG, which displays potent inhibitory activity towards human HDACs and improved antiproliferative activity in several cancer cell lines. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. HDAC Inhibitors as Epigenetic Regulators of the Immune System: Impacts on Cancer Therapy and Inflammatory Diseases

    PubMed Central

    Montgomery, McKale R.; Leyva, Kathryn J.

    2016-01-01

    Histone deacetylase (HDAC) inhibitors are powerful epigenetic regulators that have enormous therapeutic potential and have pleiotropic effects at the cellular and systemic levels. To date, HDAC inhibitors are used clinically for a wide variety of disorders ranging from hematopoietic malignancies to psychiatric disorders, are known to have anti-inflammatory properties, and are in clinical trials for several other diseases. In addition to influencing gene expression, HDAC enzymes also function as part of large, multisubunit complexes which have many nonhistone targets, alter signaling at the cellular and systemic levels, and result in divergent and cell-type specific effects. Thus, the effects of HDAC inhibitor treatment are too intricate to completely understand with current knowledge but the ability of HDAC inhibitors to modulate the immune system presents intriguing therapeutic possibilities. This review will explore the complexity of HDAC inhibitor treatment at the cellular and systemic levels and suggest strategies for effective use of HDAC inhibitors in biomedical research, focusing on the ability of HDAC inhibitors to modulate the immune system. The possibility of combining the documented anticancer effects and newly emerging immunomodulatory effects of HDAC inhibitors represents a promising new combinatorial therapeutic approach for HDAC inhibitor treatments. PMID:27556043

  14. The Class I HDAC Inhibitor RGFP963 Enhances Consolidation of Cued Fear Extinction

    ERIC Educational Resources Information Center

    Bowers, Mallory E.; Xia, Bing; Carreiro, Samantha; Ressler, Kerry J.

    2015-01-01

    Evidence indicates that broad, nonspecific histone deacetylase (HDAC) inhibition enhances learning and memory, however, the contribution of the various HDACs to specific forms of learning is incompletely understood. Here, we show that the Class I HDAC inhibitor, RGFP963, enhances consolidation of cued fear extinction. However, RGFP966, a strong…

  15. The Class I HDAC Inhibitor RGFP963 Enhances Consolidation of Cued Fear Extinction

    ERIC Educational Resources Information Center

    Bowers, Mallory E.; Xia, Bing; Carreiro, Samantha; Ressler, Kerry J.

    2015-01-01

    Evidence indicates that broad, nonspecific histone deacetylase (HDAC) inhibition enhances learning and memory, however, the contribution of the various HDACs to specific forms of learning is incompletely understood. Here, we show that the Class I HDAC inhibitor, RGFP963, enhances consolidation of cued fear extinction. However, RGFP966, a strong…

  16. Chemistry, biology, and QSAR studies of substituted biaryl hydroxamates and mercaptoacetamides as HDAC inhibitors-nanomolar-potency inhibitors of pancreatic cancer cell growth.

    PubMed

    Kozikowski, Alan P; Chen, Yufeng; Gaysin, Arsen M; Savoy, Doris N; Billadeau, Daniel D; Kim, Ki Hwan

    2008-03-01

    The histone deacetylases (HDACs) are able to regulate gene expression, and inhibitors of the HDACs (HDACIs) hold promise in the treatment of cancer as well as a variety of neurodegenerative diseases. To investigate the potential for isoform selectivity in the inhibition of HDACs, we prepared a small series of 2,4'-diaminobiphenyl ligands functionalized at the para-amino group with an appendage containing either a hydroxamate or a mercaptoacetamide group and coupled to an amino acid residue at the ortho-amino group. A smaller series of substituted phenylthiazoles was also explored. Some of these newly synthesized ligands show low-nanomolar potency in HDAC inhibition assays and display micromolar to low-nanomolar IC(50) values in tests against five pancreatic cancer cell lines. The isoform selectivity of these ligands for class I HDACs (HDAC1-3 and 8) and class IIb HDACs (HDAC6 and 10) together with QSAR studies of their correlation with lipophilicity are presented. Of particular interest is the selectivity of the mercaptoacetamides for HDAC6.

  17. Tau--an inhibitor of deacetylase HDAC6 function.

    PubMed

    Perez, Mar; Santa-Maria, Ismael; Gomez de Barreda, Elena; Zhu, Xiongwei; Cuadros, Raquel; Cabrero, Jose Roman; Sanchez-Madrid, Francisco; Dawson, Hana N; Vitek, Michael P; Perry, George; Smith, Mark A; Avila, Jesus

    2009-06-01

    Analysis of brain microtubule protein from patients with Alzheimer's disease showed decreased alpha tubulin levels along with increased acetylation of the alpha tubulin subunit, mainly in those microtubules from neurons containing neurofibrillary tau pathology. To determine the relationship of tau protein and increased tubulin acetylation, we studied the effect of tau on the acetylation-deacetylation of tubulin. Our results indicate that tau binds to the tubulin-deacetylase, histone deacetylase 6 (HDAC6), decreasing its activity with a consequent increase in tubulin acetylation. As expected, increased acetylation was also found in tubulin from wild-type mice compared with tubulin from mice lacking tau because of the tau-mediated inhibition of the deacetylase. In addition, we found that an excess of tau protein, as a HDAC6 inhibitor, prevents induction of autophagy by inhibiting proteasome function.

  18. A new HDAC inhibitor cinnamoylphenazine shows antitumor activity in association with intensive macropinocytosis.

    PubMed

    Zhu, Bing-Yan; Shang, Bo-Yang; Du, Yue; Li, Yi; Li, Liang; Xu, Xian-Dong; Zhen, Yong-Su

    2017-01-18

    Previous studies have shown that intensive macropinocytosis occurs in cancer cells and neutral red (NR) is noted for its capability to enter into the cell massively through a process mimetic to macropinocytosis. In addition, trans-cinnamic acid (tCA) has been found to be an inhibitor of histone deacetylase (HDAC). In the present study, cinnamoylphenazine (CA-PZ) that consists of NR and tCA moieties was synthesized and evaluated. As shown, CA-PZ massively entered into colon carcinoma HT-29 cells and pancreatic carcinoma MIA PaCa-2 cells and this entry was blocked by 5-(N-ethyl-N-isopropyl) amiloride (EIPA, an inhibitor of macropinocytosis), indicating a macropinocytosis-mediated uptake. Furthermore, CA-PZ markedly increased the protein expression levels of acetyl-H3, acetyl-H4 and p21 in HT-29 cells and MIA PaCa-2 cells. CA-PZ significantly inhibited the growth of colon carcinoma HT-29 and pancreatic carcinoma MIA PaCa-2 xenografts. By in vivo imaging, CA-PZ displayed prominent accumulation in the tumor xenografts. The study indicates that the newly synthesized CA-PZ acts as an HDAC inhibitor in association with intensive macropinocytosis-mediated intracellular delivery in cancer cells. The use of neutral red for preparation of chimeric molecules with the attribute of macropinocytosis-mediated intracellular delivery might open an alternative way for development of HDAC inhibitors.

  19. Sensitivity of osteosarcoma cells to HDAC inhibitor AR-42 mediated apoptosis.

    PubMed

    Murahari, Sridhar; Jalkanen, Aimee L; Kulp, Samuel K; Chen, Ching-Shih; Modiano, Jaime F; London, Cheryl A; Kisseberth, William C

    2017-01-21

    Osteosarcoma (OS) is the most common primary bone tumor in both humans and dogs and is the second leading cause of cancer related deaths in children and young adults. Limb sparing surgery along with chemotherapy has been the mainstay of treatment for OS. Many patients are not cured with current therapies, presenting a real need for developing new treatments. Histone deacetylase (HDAC) inhibitors are a promising new class of anticancer agents. In this study, we investigated the activity of the novel HDAC inhibitor AR-42 in a panel of human and canine OS cell lines. The effect of AR-42 and suberoylanilide hydroxamic acid (SAHA) alone or in combination with doxorubicin on OS cell viability was assessed. Induction of histone acetylation after HDAC inhibitor treatment was confirmed by Western blotting. Drug-induced apoptosis was analyzed by FACS. Apoptosis was assessed further by measuring caspase 3/7 enzymatic activity, nucleosome fragmentation, and caspase cleavage. Effects on Akt signaling were demonstrated by assessing phosphorylation of Akt and downstream signaling molecules. AR-42 was a potent inhibitor of cell viability and induced a greater apoptotic response compared to SAHA when used at the same concentrations. Normal osteoblasts were much less sensitive. The combination of AR-42 with doxorubicin resulted in a potent inhibition of cell viability and apparent synergistic effect. Furthermore, we showed that AR-42 and SAHA induced cell death via the activation of the intrinsic mitochondrial pathway through activation of caspase 3/7. This potent apoptotic activity was associated with the greater ability of AR-42 to downregulate survival signaling through Akt. These results confirm that AR-42 is a potent inhibitor of HDAC activity and demonstrates its ability to significantly inhibit cell survival through its pleiotropic effects in both canine and human OS cells and suggests that spontaneous OS in pet dogs may be a useful large animal model for preclinical

  20. Chemopreventive Effects of an HDAC2-Selective Inhibitor on Rat Colon Carcinogenesis and APCmin/+ Mouse Intestinal Tumorigenesis

    PubMed Central

    Ravillah, Durgadevi; Mohammed, Altaf; Qian, Li; Brewer, Misty; Zhang, Yuting; Biddick, Laura; Steele, Vernon E.

    2014-01-01

    Epigenetic modulators, particularly histone deacetylases (HDACs), are valid targets for cancer prevention and therapy. Recent studies report that HDAC2 overexpression is associated with colon tumor progression and is a potential target for colon cancer prevention. This study tested chemopreventive and dose-response effects of Ohio State University HDAC42 (OSU-HDAC42), a selective HDAC2 inhibitor, using a rat colon carcinogenesis model to assess aberrant crypt foci inhibition and a familial adenomatous polyposis model to assess intestinal tumor inhibition. Colonic aberrant crypt foci were induced by azoxymethane (AOM) (15 mg/kg body weight, once-weekly subcutaneous injections at 8 and 9 weeks age). One week after AOM treatment, groups of rats were fed an AIN-76A diet containing 0, 75, 150, and 300 ppm OSU-HDAC42 for 8 weeks, and colonic aberrant crypt foci were evaluated. To assess the inhibitory effect of OSU-HDAC42 on small-intestinal polyps and colon tumor growth, 6-week-old male C57Bl/6J-APCmin/+mice were fed an AIN-76A diet containing 150 ppm OSU-HADC42 or 300 ppm pan-HDAC inhibitor suberoylanilide hydroxyamic acid (SAHA) for 80 days. Our results demonstrate that dietary OSU-HDAC42 produced dose-dependent inhibition of AOM-induced colonic aberrant crypt foci formation (13–50%; P < 0.01 to < 0.0001) and reduced multiple crypts with ≥4 crypts per focus (25–57%; P < 0.01 to < 0.0001) in F344 rats. Our findings show that 150 ppm OSU-HDAC42 significantly inhibited small-intestinal polyps (>46%; P < 0.001), with polyp size measuring >1 mm (P < 0.001), and colon tumors (>26%) in APCmin/+mice, whereas 300 ppm SAHA showed nonsignificant inhibition. Mice fed 150 ppm OSU-HDAC42 had significantly decreased HDAC2, proliferating cell nuclear antigen, B cell lymphoma 2, cyclin-dependent kinase 2, and cell division cycle homolog 25C expression levels and increased p53 expression levels. These observations demonstrate the chemopreventive efficacy of OSU-HDAC42 against

  1. Inhibitors of histone deacetylase (HDAC) restore the p53 pathway in neuroblastoma cells

    PubMed Central

    Condorelli, F; Gnemmi, I; Vallario, A; Genazzani, A A; Canonico, P L

    2007-01-01

    Background and purpose: Inhibitors of histone deacetylase (HDAC) are emerging as a promising class of anti-cancer drugs, but a generic deregulation of transcription in neoplastic cells cannot fully explain their therapeutic effects. In this study we evaluated alternative molecular mechanisms by which HDAC inhibitors could affect neuroblastoma viability. Experimental approach: Effects of HDAC inhibitors on survival of the I-type SK-N-BE and the N-type NB SH-SY5Y neuroblastoma cell lines were assessed by the MTT assay. Molecular pathways leading to this were examined by western blot, confocal microscopy and cytofluorometry. The mRNA levels of apoptotic mediators were assessed semi-quantitatively by RT-PCR. Tumour-suppressor p53 trans activity was assessed in EMSA experiments. HDAC inhibitors were also studied in cells subjected to plasmid-based p53 interference (p53i). Key results: HDAC inhibitors induced cell death via the mitochondrial pathway of apoptosis with recruitment of Bcl-2 family members. Bcl-2 overexpression rendered neuroblastoma cells resistant to HDAC inhibitor treatment. Low concentrations of HDAC inhibitors (0.9 mM) caused a G2 cell-cycle arrest and a marked upregulation of the p21/Waf1/Cip1 protein. HDAC inhibitors also activate the p53 protein via hyper-acetylation and nuclear re-localization, without affecting its protein expression. Accordingly, HDAC inhibitor-induced cell-killing and p21/Waf1/Cip1 upregulation is impaired in p53i-cells. Conclusions and implications: In neuroblastoma cells, HDAC inhibitors may overcome the resistance to classical chemotherapeutic drugs by restoring the p53 tumour-repressor function via its hyper-acetylation and nuclear migration, events usually impaired in such tumours. In neuroblastoma cells, HDAC inhibitors are not able to induce p21/Waf1/Cip1 in the absence of a functional p53. PMID:18059320

  2. Identification of HDAC6-Selective Inhibitors of Low Cancer Cell Cytotoxicity.

    PubMed

    Gaisina, Irina N; Tueckmantel, Werner; Ugolkov, Andrey; Shen, Sida; Hoffen, Jessica; Dubrovskyi, Oleksii; Mazar, Andrew; Schoon, Renee A; Billadeau, Daniel; Kozikowski, Alan P

    2016-01-05

    The histone deacetylases (HDACs) occur in 11 different isoforms, and these enzymes regulate the activity of a large number of proteins involved in cancer initiation and progression. The discovery of isoform-selective HDAC inhibitors (HDACIs) is desirable, as it is likely that such compounds would avoid some of the undesirable side effects found with the first-generation inhibitors. A series of HDACIs previously reported by us were found to display some selectivity for HDAC6 and to induce cell-cycle arrest and apoptosis in pancreatic cancer cells. In the present work, we show that structural modification of these isoxazole-based inhibitors leads to high potency and selectivity for HDAC6 over HDAC1-3 and HDAC10, while unexpectedly abolishing their ability to block cell growth. Three inhibitors with lower HDAC6 selectivity inhibit the growth of cell lines BxPC3 and L3.6pl, and they only induce apoptosis in L3.6pl cells. We conclude that HDAC6 inhibition alone is insufficient for disruption of cell growth, and that some degree of class 1 HDAC inhibition is required. Moreover, the highly selective HDAC6Is reported herein that are weakly cytotoxic may find use in cancer immune system reactivation.

  3. Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites.

    PubMed

    Engel, Jessica A; Jones, Amy J; Avery, Vicky M; Sumanadasa, Subathdrage D M; Ng, Susanna S; Fairlie, David P; Adams, Tina S; Andrews, Katherine T

    2015-12-01

    Histone deacetylase (HDAC) enzymes work together with histone acetyltransferases (HATs) to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat(®)), romidepsin (Istodax(®)) and belinostat (Beleodaq(®)), are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10-200 nM), while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM). The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

  4. Structural basis for the design and synthesis of selective HDAC inhibitors.

    PubMed

    Di Micco, Simone; Chini, Maria Giovanna; Terracciano, Stefania; Bruno, Ines; Riccio, Raffaele; Bifulco, Giuseppe

    2013-07-01

    Histone Deacetylases are considered promising targets for cancer epigenetic therapy, and small molecules able to modulate their biological function have recently gained an increasing interest as potential anticancer agents. In spite of their potential application in cancer therapy, most HDAC inhibitors unselectively bind the several HDAC isoforms, giving rise to different side-effects. In this context, we have traced out the structural elements responsible of selective binding for the therapeutically relevant different HDAC isoforms. The structural analysis has been carried out by molecular modeling, docking in the binding pockets of HDAC1-4 and HDAC6-8, 36 inhibitors presenting a well defined selectivity for the different isoforms. As quick proof of evidence, we have designed, synthesized and experimentally tested three selective ligands. The experimental data suggest that the obtained structural guidelines can be useful tools for the rational design of new potent inhibitors against selected HDAC isoforms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Synthesis, biological characterization and molecular modeling insights of spirochromanes as potent HDAC inhibitors.

    PubMed

    Thaler, Florian; Moretti, Loris; Amici, Raffaella; Abate, Agnese; Colombo, Andrea; Carenzi, Giacomo; Fulco, Maria Carmela; Boggio, Roberto; Dondio, Giulio; Gagliardi, Stefania; Minucci, Saverio; Sartori, Luca; Varasi, Mario; Mercurio, Ciro

    2016-01-27

    In the last decades, inhibitors of histone deacetylases (HDAC) have become an important class of anti-cancer agents. In a previous study we described the synthesis of spiro[chromane-2,4'-piperidine]hydroxamic acid derivatives able to inhibit histone deacetylase enzymes. Herein, we present our exploration for new derivatives by replacing the piperidine moiety with various cycloamines. The goal was to obtain highly potent compounds with a good in vitro ADME profile. In addition, molecular modeling studies unravelled the binding mode of these inhibitors.

  6. Histone Deacetylase (HDAC) Inhibitors - emerging roles in neuronal memory, learning, synaptic plasticity and neural regeneration.

    PubMed

    Ganai, Shabir Ahmad; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

    2016-01-01

    Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed.

  7. Histone Deacetylase (HDAC) Inhibitors - Emerging Roles in Neuronal Memory, Learning, Synaptic Plasticity and Neural Regeneration

    PubMed Central

    Ahmad Ganai, Shabir; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

    2016-01-01

    Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed. PMID:26487502

  8. Metabolic inhibitors accentuate the anti-tumoral effect of HDAC5 inhibition.

    PubMed

    Hendrick, E; Peixoto, P; Blomme, A; Polese, C; Matheus, N; Cimino, J; Frère, A; Mouithys-Mickalad, A; Serteyn, D; Bettendorff, L; Elmoualij, B; De Tullio, P; Eppe, G; Dequiedt, F; Castronovo, V; Mottet, D

    2017-08-24

    The US FDA approval of broad-spectrum histone deacetylase (HDAC) inhibitors has firmly laid the cancer community to explore HDAC inhibition as a therapeutic approach for cancer treatment. Hitting one HDAC member could yield clinical benefit but this required a complete understanding of the functions of the different HDAC members. Here we explored the consequences of specific HDAC5 inhibition in cancer cells. We demonstrated that HDAC5 inhibition induces an iron-dependent reactive oxygen species (ROS) production, ultimately leading to apoptotic cell death as well as mechanisms of mitochondria quality control (mitophagy and mitobiogenesis). Interestingly, adaptation of HDAC5-depleted cells to oxidative stress passes through reprogramming of metabolic pathways towards glucose and glutamine. Therefore, interference with both glucose and glutamine supply in HDAC5-inhibited cancer cells significantly increases apoptotic cell death and reduces tumour growth in vivo; providing insight into a valuable clinical strategy combining the selective inhibition of HDAC5 with various inhibitors of metabolism as a new therapy to kill cancer cells.

  9. Discovery of a Selective Series of Inhibitors of Plasmodium falciparum HDACs.

    PubMed

    Ontoria, Jesus M; Paonessa, Giacomo; Ponzi, Simona; Ferrigno, Federica; Nizi, Emanuela; Biancofiore, Ilaria; Malancona, Savina; Graziani, Rita; Roberts, David; Willis, Paul; Bresciani, Alberto; Gennari, Nadia; Cecchetti, Ottavia; Monteagudo, Edith; Orsale, Maria V; Veneziano, Maria; Di Marco, Annalise; Cellucci, Antonella; Laufer, Ralph; Altamura, Sergio; Summa, Vincenzo; Harper, Steven

    2016-05-12

    The identification of a new series of P. falciparum growth inhibitors is described. Starting from a series of known human class I HDAC inhibitors a SAR exploration based on growth inhibitory activity in parasite and human cells-based assays led to the identification of compounds with submicromolar inhibition of P. falciparum growth (EC50 < 500 nM) and good selectivity over the activity of human HDAC in cells (up to >50-fold). Inhibition of parasital HDACs as the mechanism of action of this new class of selective growth inhibitors is supported by hyperacetylation studies.

  10. Discovery of a Selective Series of Inhibitors of Plasmodium falciparum HDACs

    PubMed Central

    2016-01-01

    The identification of a new series of P. falciparum growth inhibitors is described. Starting from a series of known human class I HDAC inhibitors a SAR exploration based on growth inhibitory activity in parasite and human cells-based assays led to the identification of compounds with submicromolar inhibition of P. falciparum growth (EC50 < 500 nM) and good selectivity over the activity of human HDAC in cells (up to >50-fold). Inhibition of parasital HDACs as the mechanism of action of this new class of selective growth inhibitors is supported by hyperacetylation studies. PMID:27190592

  11. A Rational Approach for the Identification of Non-Hydroxamate HDAC6-Selective Inhibitors

    NASA Astrophysics Data System (ADS)

    Goracci, Laura; Deschamps, Nathalie; Randazzo, Giuseppe Marco; Petit, Charlotte; Dos Santos Passos, Carolina; Carrupt, Pierre-Alain; Simões-Pires, Claudia; Nurisso, Alessandra

    2016-07-01

    The human histone deacetylase isoform 6 (HDAC6) has been demonstrated to play a major role in cell motility and aggresome formation, being interesting for the treatment of multiple tumour types and neurodegenerative conditions. Currently, most HDAC inhibitors in preclinical or clinical evaluations are non-selective inhibitors, characterised by a hydroxamate zinc-binding group (ZBG) showing off-target effects and mutagenicity. The identification of selective HDAC6 inhibitors with novel chemical properties has not been successful yet, also because of the absence of crystallographic information that makes the rational design of HDAC6 selective inhibitors difficult. Using HDAC inhibitory data retrieved from the ChEMBL database and ligand-based computational strategies, we identified 8 original new non-hydroxamate HDAC6 inhibitors from the SPECS database, with activity in the low μM range. The most potent and selective compound, bearing a hydrazide ZBG, was shown to increase tubulin acetylation in human cells. No effects on histone H4 acetylation were observed. To the best of our knowledge, this is the first report of an HDAC6 selective inhibitor bearing a hydrazide ZBG. Its capability to passively cross the blood-brain barrier (BBB), as observed through PAMPA assays, and its low cytotoxicity in vitro, suggested its potential for drug development.

  12. A Rational Approach for the Identification of Non-Hydroxamate HDAC6-Selective Inhibitors

    PubMed Central

    Goracci, Laura; Deschamps, Nathalie; Randazzo, Giuseppe Marco; Petit, Charlotte; Dos Santos Passos, Carolina; Carrupt, Pierre-Alain; Simões-Pires, Claudia; Nurisso, Alessandra

    2016-01-01

    The human histone deacetylase isoform 6 (HDAC6) has been demonstrated to play a major role in cell motility and aggresome formation, being interesting for the treatment of multiple tumour types and neurodegenerative conditions. Currently, most HDAC inhibitors in preclinical or clinical evaluations are non-selective inhibitors, characterised by a hydroxamate zinc-binding group (ZBG) showing off-target effects and mutagenicity. The identification of selective HDAC6 inhibitors with novel chemical properties has not been successful yet, also because of the absence of crystallographic information that makes the rational design of HDAC6 selective inhibitors difficult. Using HDAC inhibitory data retrieved from the ChEMBL database and ligand-based computational strategies, we identified 8 original new non-hydroxamate HDAC6 inhibitors from the SPECS database, with activity in the low μM range. The most potent and selective compound, bearing a hydrazide ZBG, was shown to increase tubulin acetylation in human cells. No effects on histone H4 acetylation were observed. To the best of our knowledge, this is the first report of an HDAC6 selective inhibitor bearing a hydrazide ZBG. Its capability to passively cross the blood-brain barrier (BBB), as observed through PAMPA assays, and its low cytotoxicity in vitro, suggested its potential for drug development. PMID:27404291

  13. Antidepressant-Like Properties of Novel HDAC6-Selective Inhibitors with Improved Brain Bioavailability

    PubMed Central

    Jochems, Jeanine; Boulden, Janette; Lee, Bridgin G; Blendy, Julie A; Jarpe, Matthew; Mazitschek, Ralph; Van Duzer, John H; Jones, Simon; Berton, Olivier

    2014-01-01

    HDAC inhibitors have been reported to produce antidepressant and pro-cognitive effects in animal models, however, poor brain bioavailability or lack of isoform selectivity of current probes has limited our understanding of their mode of action. We report the characterization of novel pyrimidine hydroxyl amide small molecule inhibitors of HDAC6, brain bioavailable upon systemic administration. We show that two compounds in this family, ACY-738 and ACY-775, inhibit HDAC6 with low nanomolar potency and a selectivity of 60- to 1500-fold over class I HDACs. In contrast to tubastatin A, a reference HDAC6 inhibitor with similar potency and peripheral activity, but more limited brain bioavailability, ACY-738 and ACY-775 induce dramatic increases in α-tubulin acetylation in brain and stimulate mouse exploratory behaviors in novel, but not familiar environments. Interestingly, despite a lack of detectable effect on histone acetylation, we show that ACY-738 and ACY-775 share the antidepressant-like properties of other HDAC inhibitors, such as SAHA and MS-275, in the tail suspension test and social defeat paradigm. These effects of ACY-738 and ACY-775 are directly attributable to the inhibition of HDAC6 expressed centrally, as they are fully abrogated in mice with a neural-specific loss of function of HDAC6. Furthermore, administered in combination, a behaviorally inactive dose of ACY-738 markedly potentiates the anti-immobility activity of a subactive dose of the selective serotonin reuptake inhibitor citalopram. Our results validate new isoform-selective probes for in vivo pharmacological studies of HDAC6 in the CNS and reinforce the viability of this HDAC isoform as a potential target for antidepressant development. PMID:23954848

  14. Mechanism of Action of 2-Aminobenzamide HDAC Inhibitors in Reversing Gene Silencing in Friedreich's Ataxia.

    PubMed

    Soragni, Elisabetta; Chou, C James; Rusche, James R; Gottesfeld, Joel M

    2015-01-01

    The genetic defect in Friedreich's ataxia (FRDA) is the hyperexpansion of a GAA•TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Histone post-translational modifications near the expanded repeats are consistent with heterochromatin formation and consequent FXN gene silencing. Using a newly developed human neuronal cell model, derived from patient-induced pluripotent stem cells, we find that 2-aminobenzamide histone deacetylase (HDAC) inhibitors increase FXN mRNA levels and frataxin protein in FRDA neuronal cells. However, only compounds targeting the class I HDACs 1 and 3 are active in increasing FXN mRNA in these cells. Structural analogs of the active HDAC inhibitors that selectively target either HDAC1 or HDAC3 do not show similar increases in FXN mRNA levels. To understand the mechanism of action of these compounds, we probed the kinetic properties of the active and inactive inhibitors, and found that only compounds that target HDACs 1 and 3 exhibited a slow-on/slow-off mechanism of action for the HDAC enzymes. HDAC1- and HDAC3-selective compounds did not show this activity. Using siRNA methods in the FRDA neuronal cells, we show increases in FXN mRNA upon silencing of either HDACs 1 or 3, suggesting the possibility that inhibition of each of these class I HDACs is necessary for activation of FXN mRNA synthesis, as there appears to be redundancy in the silencing mechanism caused by the GAA•TTC repeats. Moreover, inhibitors must have a long residence time on their target enzymes for this activity. By interrogating microarray data from neuronal cells treated with inhibitors of different specificity, we selected two genes encoding histone macroH2A (H2AFY2) and Polycomb group ring finger 2 (PCGF2) that were specifically down-regulated by the inhibitors targeting HDACs1 and 3 versus the more selective inhibitors for further investigation. Both genes are involved in transcriptional repression and we speculate

  15. Studies of benzamide- and thiol-based histone deacetylase inhibitors in models of oxidative-stress-induced neuronal death: identification of some HDAC3-selective inhibitors.

    PubMed

    Chen, Yufeng; He, Rong; Chen, Yihua; D'Annibale, Melissa A; Langley, Brett; Kozikowski, Alan P

    2009-05-01

    We compare three structurally different classes of histone deacetylase (HDAC) inhibitors that contain benzamide, hydroxamate, or thiol groups as the zinc binding group (ZBG) for their ability to protect cortical neurons in culture from cell death induced by oxidative stress. This study reveals that none of the benzamide-based HDAC inhibitors (HDACIs) provides any neuroprotection whatsoever, in distinct contrast to HDACIs that contain other ZBGs. Some of the sulfur-containing HDACIs, namely the thiols, thioesters, and disulfides present modest neuroprotective activity but show toxicity at higher concentrations. Taken together, these data demonstrate that the HDAC6-selective mercaptoacetamides that were reported previously provide the best protection in the homocysteic acid model of oxidative stress, thus further supporting their study in animal models of neurodegenerative diseases.

  16. The Role of Dietary Histone Deacetylases (HDACs) Inhibitors in Health and Disease

    PubMed Central

    Bassett, Shalome A.; Barnett, Matthew P. G.

    2014-01-01

    Modification of the histone proteins associated with DNA is an important process in the epigenetic regulation of DNA structure and function. There are several known modifications to histones, including methylation, acetylation, and phosphorylation, and a range of factors influence each of these. Histone deacetylases (HDACs) remove the acetyl group from lysine residues within a range of proteins, including transcription factors and histones. Whilst this means that their influence on cellular processes is more complex and far-reaching than histone modifications alone, their predominant function appears to relate to histones; through deacetylation of lysine residues they can influence expression of genes encoded by DNA linked to the histone molecule. HDAC inhibitors in turn regulate the activity of HDACs, and have been widely used as therapeutics in psychiatry and neurology, in which a number of adverse outcomes are associated with aberrant HDAC function. More recently, dietary HDAC inhibitors have been shown to have a regulatory effect similar to that of pharmacological HDAC inhibitors without the possible side-effects. Here, we discuss a number of dietary HDAC inhibitors, and how they may have therapeutic potential in the context of a whole food. PMID:25322459

  17. HDAC inhibitors induce epithelial-mesenchymal transition in colon carcinoma cells.

    PubMed

    Ji, Meiying; Lee, Eun Jeoung; Kim, Ki Bae; Kim, Yangmi; Sung, Rohyun; Lee, Sang-Jeon; Kim, Don Soo; Park, Seon Mee

    2015-05-01

    The effects of histone deacetylase (HDAC) inhibitors on epithelial-mesenchymal transition (EMT) differ in various types of cancers. We investigated the EMT phenotype in four colon cancer cell lines when challenged with HDAC inhibitors trichostatin A (TSA) and valproic acid (VPA) with or without transforming growth factor-β1 (TGF-β1) treatment. Four colon cancer cell lines with different phenotypes in regards to tumorigenicity, microsatellite stability and DNA mutation were used. EMT phenotypes were assessed by the expression of E-cadherin and vimentin using western blot analysis, immunofluorescence, quantitative real-time RT-PCR following treatment with TSA (100 or 200 nM) or VPA (0.5 mM) with or without TGF-β1 (5 ng/ml) for 24 h. Biological EMT phenotypes were also evaluated by cell morphology, migration and invasion assays. TSA or VPA induced mesenchymal features in the colon carcinoma cells by a decrease in E-cadherin and an increase in vimentin expression at the mRNA and protein levels. Confocal microscopy revealed membranous attenuation or nuclear translocation of E-cadherin and enhanced expression of vimentin. These responses occurred after 6 h and increased until 24 h. Colon cancer cells changed from a round or rectangular shape to a spindle shape with increased migration and invasion ability following TSA or VPA treatment. The susceptibility to EMT changes induced by TSA or VPA was comparable in microsatellite stable (SW480 and HT29) and microsatellite unstable cells (DLD1 and HCT116). TSA or VPA induced a mesenchymal phenotype in the colon carcinoma cells and these effects were augmented in the presence of TGF-β1. HDAC inhibitors require careful caution before their application as new anticancer drugs for colon cancers.

  18. Efficacious proteasome/HDAC inhibitor combination therapy for primary effusion lymphoma.

    PubMed

    Bhatt, Shruti; Ashlock, Brittany M; Toomey, Ngoc L; Diaz, Luis A; Mesri, Enrique A; Lossos, Izidore S; Ramos, Juan Carlos

    2013-06-01

    Primary effusion lymphoma (PEL) is a rare form of aggressive B cell lymphoma caused by Kaposi's sarcoma-associated herpesvirus (KSHV). Current chemotherapy approaches result in dismal outcomes, and there is an urgent need for new PEL therapies. Previously, we established, in a direct xenograft model of PEL-bearing immune-compromised mice, that treatment with the proteasome inhibitor, bortezomib (Btz), increased survival relative to that after treatment with doxorubicin. Herein, we demonstrate that the combination of Btz with the histone deacetylase (HDAC) inhibitor suberoylanilidehydroxamic acid (SAHA, also known as vorinostat) potently reactivates KSHV lytic replication and induces PEL cell death, resulting in significantly prolonged survival of PEL-bearing mice. Importantly, Btz blocked KSHV late lytic gene expression, terminally inhibiting the full lytic cascade and production of infectious virus in vivo. Btz treatment led to caspase activation and induced DNA damage, as evidenced by the accumulation of phosphorylated γH2AX and p53. The addition of SAHA to Btz treatment was synergistic, as SAHA induced early acetylation of p53 and reduced interaction with its negative regulator MDM2, augmenting the effects of Btz. The eradication of KSHV-infected PEL cells without increased viremia in mice provides a strong rationale for using the proteasome/HDAC inhibitor combination therapy in PEL.

  19. Rational design and simple chemistry yield a superior, neuroprotective HDAC6 inhibitor, tubastatin A.

    PubMed

    Butler, Kyle V; Kalin, Jay; Brochier, Camille; Vistoli, Guilio; Langley, Brett; Kozikowski, Alan P

    2010-08-11

    Structure-based drug design combined with homology modeling techniques were used to develop potent inhibitors of HDAC6 that display superior selectivity for the HDAC6 isozyme compared to other inhibitors. These inhibitors can be assembled in a few synthetic steps, and thus are readily scaled up for in vivo studies. An optimized compound from this series, designated Tubastatin A, was tested in primary cortical neuron cultures in which it was found to induce elevated levels of acetylated alpha-tubulin, but not histone, consistent with its HDAC6 selectivity. Tubastatin A also conferred dose-dependent protection in primary cortical neuron cultures against glutathione depletion-induced oxidative stress. Importantly, when given alone at all concentrations tested, this hydroxamate-containing HDAC6-selective compound displayed no neuronal toxicity, thus, forecasting the potential application of this agent and its analogues to neurodegenerative conditions.

  20. Phenylpyrrole-based HDAC inhibitors: synthesis, molecular modeling and biological studies.

    PubMed

    Brindisi, Margherita; Cavella, Caterina; Brogi, Simone; Nebbioso, Angela; Senger, Johanna; Maramai, Samuele; Ciotta, Alfonso; Iside, Concetta; Butini, Stefania; Lamponi, Stefania; Novellino, Ettore; Altucci, Lucia; Jung, Manfred; Campiani, Giuseppe; Gemma, Sandra

    2016-09-01

    Histone deacetylases (HDACs) regulate the expression and activity of numerous proteins involved in the initiation and progression of cancer. Currently, three hydroxamate-containing HDAC pan-inhibitors have been approved as antitumor agents. We herein present the development of a series of novel phenylpyrrole-based derivatives stemmed from combined computational and medicinal chemistry efforts to rationally modulate HDAC1/6 isoform selectivity. In vitro activity on HDAC1 and HDAC6 isoforms and the effects of selected analogs on histone H3 and α-tubulin acetylation levels were determined. Cell-based data evidenced, for selected compounds, a promising antitumor potential and low toxicity on normal cells. The newly developed compounds represent a valuable starting point for the development of novel anticancer agents.

  1. Selective class II HDAC inhibitors impair myogenesis by modulating the stability and activity of HDAC–MEF2 complexes

    PubMed Central

    Nebbioso, Angela; Manzo, Fabio; Miceli, Marco; Conte, Mariarosaria; Manente, Lucrezia; Baldi, Alfonso; De Luca, Antonio; Rotili, Dante; Valente, Sergio; Mai, Antonello; Usiello, Alessandro; Gronemeyer, Hinrich; Altucci, Lucia

    2009-01-01

    Histone deacetylase (HDAC) inhibitors are promising new epi-drugs, but the presence of both class I and class II enzymes in HDAC complexes precludes a detailed elucidation of the individual HDAC functions. By using the class II-specific HDAC inhibitor MC1568, we separated class I- and class II-dependent effects and defined the roles of class II enzymes in muscle differentiation in cultured cells and in vivo. MC1568 arrests myogenesis by (i) decreasing myocyte enhancer factor 2D (MEF2D) expression, (ii) by stabilizing the HDAC4–HDAC3–MEF2D complex, and (iii) paradoxically, by inhibiting differentiation-induced MEF2D acetylation. In vivo MC1568 shows an apparent tissue-selective HDAC inhibition. In skeletal muscle and heart, MC1568 inhibits the activity of HDAC4 and HDAC5 without affecting HDAC3 activity, thereby leaving MEF2–HDAC complexes in a repressed state. Our results suggest that HDAC class II-selective inhibitors might have a therapeutic potential for the treatment of muscle and heart diseases. PMID:19498465

  2. Imbalance between HAT and HDAC Activities in the PBMCs of Patients with Ankylosing Spondylitis or Rheumatoid Arthritis and Influence of HDAC Inhibitors on TNF Alpha Production

    PubMed Central

    Toussirot, Eric; Abbas, Wasim; Khan, Kashif Aziz; Tissot, Marion; Jeudy, Alicia; Baud, Lucile; Bertolini, Ewa; Wendling, Daniel; Herbein, Georges

    2013-01-01

    Objective Acetylation or deacetylation of histone proteins may modulate cytokine gene transcription such as TNF alpha (TNF). We evaluated the balance between histone deacetytlase (HDAC) and histone acetyltransferase (HAT) in patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) compared to healthy controls (HC) and determined the influence of HDAC inhibitors (trichostatin A -TSA- or Sirtinol -Sirt-) on these enzymatic activities and on the PBMC production of TNF. Methods 52 patients with RA, 21 with AS and 38 HC were evaluated. HAT and HDAC activities were measured on nuclear extracts from PBMC using colorimetric assays. Enzymatic activities were determined prior to and after ex vivo treatment of PBMC by TSA or Sirt. TNF levels were evaluated in PBMC culture supernatants in the absence or presence of TSA or Sirt. Results HAT and HDAC activities were significantly reduced in AS, while these activities reached similar levels in RA and HC. Ex vivo treatment of PBMC by HDACi tended to decrease HDAC expression in HC, but Sirt significantly reduced HAT in RA. TNF production by PBMC was significantly down-regulated by Sirt in HC and AS patients. Conclusion HAT and HDAC were disturbed in AS while no major changes were found in RA. HDACi may modulate HDAC and HAT PBMC expression, especially Sirt in RA. Sirtinol was able to down regulate TNF production by PBMC in HC and AS. An imbalance between HAT and HDAC activities might provide the rationale for the development of HDACi in the therapeutic approach to inflammatory rheumatic diseases. PMID:24039666

  3. Class I HDAC Inhibitors: Potential New Epigenetic Therapeutics for Alcohol Use Disorder (AUD).

    PubMed

    Bourguet, Erika; Ozdarska, Katarzyna; Moroy, Gautier; Jeanblanc, Jérôme; Naassila, Mickaël

    2017-08-22

    Alcohol use disorder (AUD) represents a serious public health issue, and discovery of new therapies is a pressing necessity. Alcohol exposure has been widely demonstrated to modulate epigenetic mechanisms, such as histone acetylation/deacetylation balance, in part via histone deacetylase (HDAC) inhibition. Epigenetic factors have been suggested to play a key role in AUD. To date, 18 different mammalian HDAC isoforms have been identified, and these have been divided into four classes. Since recent studies have suggested that both epigenetic mechanisms underlying AUD and the efficacy of HDAC inhibitors (HDACIs) in different animal models of AUD may involve class I HDACs, we herein report the development of class I HDACIs, including information regarding their structure, potency, and selectivity. More effort is required to improve the selectivity, pharmacokinetics, and toxicity profiles of HDACIs to achieve a better understanding of their efficacy in reducing addictive behavior.

  4. HDAC Inhibitors and RECK Modulate Endoplasmic Reticulum Stress in Tumor Cells

    PubMed Central

    Chen, Yun; Tsai, Ya-Hui; Tseng, Sheng-Hong

    2017-01-01

    In the tumor microenvironment hypoxia and nutrient deprived states can induce endoplasmic reticulum (ER) stress. If ER stress is not relieved, the tumor cells may become apoptotic. Therefore, targeting ER homeostasis is a potential strategy for cancer treatment. Various chemotherapeutic agents including histone deacetylase (HDAC) inhibitors can induce ER stress to cause cell death in cancers. Some HDAC inhibitors can prevent HDAC from binding to the specificity protein 1-binding site of the promoter of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) and up-regulate RECK expression. Up-regulation of RECK expression by HDAC inhibitors has been observed in various cancer types. RECK is a tumor and metastasis suppressor gene and is critical for regulating tumor cell invasiveness and metastasis. RECK also modulates ER stress via binding to and sequestering glucose-regulated protein 78 protein, so that the transmembrane sensors, such as protein kinase RNA-like ER kinase are released to activate eukaryotic translational initiation factor 2α phosphorylation and enhance ER stress. Therefore, HDAC inhibitors may directly induce ER stress or indirectly induce this stress by up-regulating RECK in cancer cells. PMID:28134767

  5. HDAC Inhibitors and RECK Modulate Endoplasmic Reticulum Stress in Tumor Cells.

    PubMed

    Chen, Yun; Tsai, Ya-Hui; Tseng, Sheng-Hong

    2017-01-26

    In the tumor microenvironment hypoxia and nutrient deprived states can induce endoplasmic reticulum (ER) stress. If ER stress is not relieved, the tumor cells may become apoptotic. Therefore, targeting ER homeostasis is a potential strategy for cancer treatment. Various chemotherapeutic agents including histone deacetylase (HDAC) inhibitors can induce ER stress to cause cell death in cancers. Some HDAC inhibitors can prevent HDAC from binding to the specificity protein 1-binding site of the promoter of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) and up-regulate RECK expression. Up-regulation of RECK expression by HDAC inhibitors has been observed in various cancer types. RECK is a tumor and metastasis suppressor gene and is critical for regulating tumor cell invasiveness and metastasis. RECK also modulates ER stress via binding to and sequestering glucose-regulated protein 78 protein, so that the transmembrane sensors, such as protein kinase RNA-like ER kinase are released to activate eukaryotic translational initiation factor 2α phosphorylation and enhance ER stress. Therefore, HDAC inhibitors may directly induce ER stress or indirectly induce this stress by up-regulating RECK in cancer cells.

  6. HDAC-inhibitor (S)-8 disrupts HDAC6-PP1 complex prompting A375 melanoma cell growth arrest and apoptosis

    PubMed Central

    Balliu, Manjola; Guandalini, Luca; Romanelli, Maria Novella; D'Amico, Massimo; Paoletti, Francesco

    2015-01-01

    Histone deacetylase inhibitors (HDACi) are agents capable of inducing growth arrest and apoptosis in different tumour cell types. Previously, we reported a series of novel HDACi obtained by hybridizing SAHA or oxamflatin with 1,4-benzodiazepines. Some of these hybrids proved effective against haematological and solid cancer cells and, above all, compound (S)-8 has emerged for its activities in various biological systems. Here, we describe the effectiveness of (S)-8 against highly metastatic human A375 melanoma cells by using normal PIG1 melanocytes as control. (S)-8 prompted: acetylation of histones H3/H4 and α-tubulin; G0/G1 and G2/M cell cycle arrest by rising p21 and hypophos-phorylated RB levels; apoptosis involving the cleavage of PARP and caspase 9, BAD protein augmentation and cytochrome c release; decrease in cell motility, invasiveness and pro-angiogenic potential as shown by results of wound-healing assay, down-regulation of MMP-2 and VEGF-A/VEGF-R2, besides TIMP-1/TIMP-2 up-regulation; and also intracellular accumulation of melanin and neutral lipids. The pan-caspase inhibitor Z-VAD-fmk, but not the antioxidant N-acetyl-cysteine, contrasted these events. Mechanistically, (S)-8 allows the disruption of cytoplasmic HDAC6-protein phosphatase 1 (PP1) complex in A375 cells thus releasing the active PP1 that dephosphorylates AKT and blocks its downstream pro-survival signalling. This view is consistent with results obtained by: inhibiting PP1 with Calyculin A; using PPP1R2-transfected cells with impaired PP1 activity; monitoring drug-induced HDAC6-PP1 complex re-shuffling; and, abrogating HDAC6 expression with specific siRNA. Altogether, (S)-8 proved very effective against melanoma A375 cells, but not normal melanocytes, and safe to normal mice thus offering attractive clinical prospects for treating this aggressive malignancy. PMID:25376115

  7. Enhancement of pomalidomide anti-tumor response with ACY-241, a selective HDAC6 inhibitor

    PubMed Central

    Tamang, David; Yang, Min; Jones, Simon S.; Quayle, Steven N.

    2017-01-01

    Thalidomide-based Immunomodulatory Drugs (IMiDs®), including lenalidomide and pomalidomide, are effective therapeutics for multiple myeloma. These agents have been approved with, or are under clinical development with, other targeted therapies including proteasome inhibitors, αCD38 monoclonal antibodies, as well as histone deacetylase (HDAC) inhibitors for combination therapy. HDAC inhibitors broadly targeting Class I and IIb HDACs have shown potent preclinical efficacy but have frequently demonstrated an undesirable safety profile in combination therapy approaches in clinical studies. Therefore, development of more selective HDAC inhibitors could provide enhanced efficacy with reduced side effects in combination with IMiDs® for the treatment of B-cell malignancies, including multiple myeloma. Here, the second generation selective HDAC6 inhibitor citarinostat (ACY-241), with a more favorable safety profile than non-selective pan-HDAC inhibitors, is shown to synergize with pomalidomide in in vitro assays through promoting greater apoptosis and cell cycle arrest. Furthermore, utilizing a multiple myeloma in vivo murine xenograft model, combination treatment with pomalidomide and ACY-241 leads to increased tumor growth inhibition. At the molecular level, combination treatment with ACY-241 and pomalidomide leads to greater suppression of the pro-survival factors survivin, Myc, and IRF4. The results presented here demonstrate synergy between pomalidomide and ACY-241 in both in vitro and in vivo preclinical models, providing further impetus for clinical development of ACY-241 for use in combination with IMiDs for patients with multiple myeloma and potentially other B-cell malignancies. PMID:28264055

  8. HDAC3-selective inhibitor enhances extinction of cocaine-seeking behavior in a persistent manner.

    PubMed

    Malvaez, Melissa; McQuown, Susan C; Rogge, George A; Astarabadi, Mariam; Jacques, Vincent; Carreiro, Samantha; Rusche, James R; Wood, Marcelo A

    2013-02-12

    Nonspecific histone deacetylase (HDAC) inhibition has been shown to facilitate the extinction of drug-seeking behavior in a manner resistant to reinstatement. A key open question is which specific HDAC is involved in the extinction of drug-seeking behavior. Using the selective HDAC3 inhibitor RGFP966, we investigated the role of HDAC3 in extinction and found that systemic treatment with RGFP966 facilitates extinction in mice in a manner resistant to reinstatement. We also investigated whether the facilitated extinction is related to the enhancement of extinction consolidation during extinction learning or to negative effects on performance or reconsolidation. These are key distinctions with regard to any compound being used to modulate extinction, because a more rapid decrease in a defined behavior is interpreted as facilitated extinction. Using an innovative combination of behavioral paradigms, we found that a single treatment of RGFP966 enhances extinction of a previously established cocaine-conditioned place preference, while simultaneously enhancing long-term object-location memory within subjects. During extinction consolidation, HDAC3 inhibition promotes a distinct pattern of histone acetylation linked to gene expression within the infralimbic cortex, hippocampus, and nucleus accumbens. Thus, the facilitated extinction of drug-seeking cannot be explained by adverse effects on performance. These results demonstrate that HDAC3 inhibition enhances the memory processes involved in extinction of drug-seeking behavior.

  9. Dissecting structure-activity-relationships of crebinostat: Brain penetrant HDAC inhibitors for neuroepigenetic regulation.

    PubMed

    Ghosh, Balaram; Zhao, Wen-Ning; Reis, Surya A; Patnaik, Debasis; Fass, Daniel M; Tsai, Li-Huei; Mazitschek, Ralph; Haggarty, Stephen J

    2016-02-15

    Targeting chromatin-mediated epigenetic regulation has emerged as a potential avenue for developing novel therapeutics for a wide range of central nervous system disorders, including cognitive disorders and depression. Histone deacetylase (HDAC) inhibitors have been pursued as cognitive enhancers that impact the regulation of gene expression and other mechanisms integral to neuroplasticity. Through systematic modification of the structure of crebinostat, a previously discovered cognitive enhancer that affects genes critical to memory and enhances synaptogenesis, combined with biochemical and neuronal cell-based screening, we identified a novel hydroxamate-based HDAC inhibitor, here named neurinostat, with increased potency compared to crebinostat in inducing neuronal histone acetylation. In addition, neurinostat was found to have a pharmacokinetic profile in mouse brain modestly improved over that of crebinostat. This discovery of neurinostat and demonstration of its effects on neuronal HDACs adds to the available pharmacological toolkit for dissecting the molecular and cellular mechanisms of neuroepigenetic regulation in health and disease.

  10. Metabolic Effects of Known and Novel HDAC and SIRT Inhibitors in Glioblastomas Independently or Combined with Temozolomide.

    PubMed

    Cuperlovic-Culf, Miroslava; Touaibia, Mohamed; St-Coeur, Patrick-Denis; Poitras, Julie; Morin, Pier; Culf, Adrian S

    2014-09-12

    Inhibition of protein deacetylation enzymes, alone or in combination with standard chemotherapies, is an exciting addition to cancer therapy. We have investigated the effect of deacetylase inhibition on the metabolism of glioblastoma cells. 1H NMR metabolomics analysis was used to determine the major metabolic changes following treatment of two distinct glioblastoma cell lines, U373 and LN229, with five different histone deacetylase (HDAC) inhibitors, as well as one inhibitor of NAD+-dependent protein deacetylases (SIRT). The addition of the standard glioblastoma chemotherapy agent, temozolomide, to the HDAC and SIRT treatments led to a reduction in cell survival, suggesting a possibility for combined treatment. This study shows that distinct glioblastoma cell lines, with different metabolic profiles and gene expression, experience dissimilar changes following treatment with protein deacetylase inhibitors. The observed effects of inhibitors on mitochondrial metabolism, glycolysis and fatty acid synthesis suggest possible roles of protein deacetylases in metabolism regulation. Metabolic markers of the effectiveness of anti-protein deacetylase treatments have been explored. In addition to known deacetylation inhibitors, three novel inhibitors have been introduced and tested. Finally, 1H NMR analysis of cellular metabolism is shown to be a fast, inexpensive method for testing drug effects.

  11. Metabolic Effects of Known and Novel HDAC and SIRT Inhibitors in Glioblastomas Independently or Combined with Temozolomide

    PubMed Central

    Cuperlovic-Culf, Miroslava; Touaibia, Mohamed; St-Coeur, Patrick-Denis; Poitras, Julie; Morin, Pier Jr; Culf, Adrian S.

    2014-01-01

    Inhibition of protein deacetylation enzymes, alone or in combination with standard chemotherapies, is an exciting addition to cancer therapy. We have investigated the effect of deacetylase inhibition on the metabolism of glioblastoma cells. 1H NMR metabolomics analysis was used to determine the major metabolic changes following treatment of two distinct glioblastoma cell lines, U373 and LN229, with five different histone deacetylase (HDAC) inhibitors, as well as one inhibitor of NAD+-dependent protein deacetylases (SIRT). The addition of the standard glioblastoma chemotherapy agent, temozolomide, to the HDAC and SIRT treatments led to a reduction in cell survival, suggesting a possibility for combined treatment. This study shows that distinct glioblastoma cell lines, with different metabolic profiles and gene expression, experience dissimilar changes following treatment with protein deacetylase inhibitors. The observed effects of inhibitors on mitochondrial metabolism, glycolysis and fatty acid synthesis suggest possible roles of protein deacetylases in metabolism regulation. Metabolic markers of the effectiveness of anti-protein deacetylase treatments have been explored. In addition to known deacetylation inhibitors, three novel inhibitors have been introduced and tested. Finally, 1H NMR analysis of cellular metabolism is shown to be a fast, inexpensive method for testing drug effects. PMID:25222834

  12. A Thoroughly Validated Virtual Screening Strategy for Discovery of Novel HDAC3 Inhibitors

    PubMed Central

    Hu, Huabin; Xia, Jie; Wang, Dongmei; Wang, Xiang Simon; Wu, Song

    2017-01-01

    Histone deacetylase 3 (HDAC3) has been recently identified as a potential target for the treatment of cancer and other diseases, such as chronic inflammation, neurodegenerative diseases, and diabetes. Virtual screening (VS) is currently a routine technique for hit identification, but its success depends on rational development of VS strategies. To facilitate this process, we applied our previously released benchmarking dataset, i.e., MUBD-HDAC3 to the evaluation of structure-based VS (SBVS) and ligand-based VS (LBVS) combinatorial approaches. We have identified FRED (Chemgauss4) docking against a structural model of HDAC3, i.e., SAHA-3 generated by a computationally inexpensive “flexible docking”, as the best SBVS approach and a common feature pharmacophore model, i.e., Hypo1 generated by Catalyst/HipHop as the optimal model for LBVS. We then developed a pipeline that was composed of Hypo1, FRED (Chemgauss4), and SAHA-3 sequentially, and demonstrated that it was superior to other combinations in terms of ligand enrichment. In summary, we present the first highly-validated, rationally-designed VS strategy specific to HDAC3 inhibitor discovery. The constructed pipeline is publicly accessible for the scientific community to identify novel HDAC3 inhibitors in a time-efficient and cost-effective way. PMID:28106794

  13. A Thoroughly Validated Virtual Screening Strategy for Discovery of Novel HDAC3 Inhibitors.

    PubMed

    Hu, Huabin; Xia, Jie; Wang, Dongmei; Wang, Xiang Simon; Wu, Song

    2017-01-18

    Histone deacetylase 3 (HDAC3) has been recently identified as a potential target for the treatment of cancer and other diseases, such as chronic inflammation, neurodegenerative diseases, and diabetes. Virtual screening (VS) is currently a routine technique for hit identification, but its success depends on rational development of VS strategies. To facilitate this process, we applied our previously released benchmarking dataset, i.e., MUBD-HDAC3 to the evaluation of structure-based VS (SBVS) and ligand-based VS (LBVS) combinatorial approaches. We have identified FRED (Chemgauss4) docking against a structural model of HDAC3, i.e., SAHA-3 generated by a computationally inexpensive "flexible docking", as the best SBVS approach and a common feature pharmacophore model, i.e., Hypo1 generated by Catalyst/HipHop as the optimal model for LBVS. We then developed a pipeline that was composed of Hypo1, FRED (Chemgauss4), and SAHA-3 sequentially, and demonstrated that it was superior to other combinations in terms of ligand enrichment. In summary, we present the first highly-validated, rationally-designed VS strategy specific to HDAC3 inhibitor discovery. The constructed pipeline is publicly accessible for the scientific community to identify novel HDAC3 inhibitors in a time-efficient and cost-effective way.

  14. Inhibition and Mechanism of HDAC8 Revisited

    PubMed Central

    2015-01-01

    Histone deacetylases (HDACs) have found intense interest as drug targets for a variety of diseases, but there is disagreement about basic aspects of the inhibition and mechanism of HDACs. QM/MM calculations of HDAC8 including a large QM region provide a model that is consistent with the available crystal structures and structure–activity relationships of different HDAC inhibitors. The calculations support a spontaneous proton transfer from a hydroxamic acid to an active site histidine upon binding to the zinc. The role of the H142/D176 catalytic dyad as the general base of the reaction is elucidated. The reasons for the disagreements between previous proposals are discussed. The results provide detailed insights into the unique mechanism of HDACs, including the role of the two catalytic dyads and function of the potassium near the active site. They also have important implications for the design of novel inhibitors for a number of HDACs such as the class IIa HDACs. PMID:25060069

  15. Medicinal Chemistry Insights into Novel HDAC Inhibitors: An Updated Patent Review (2012-2016).

    PubMed

    Zhan, Peng; Wang, Xueshun; Liu, Xinyong; Suzuki, Takayoshi

    2017-01-01

    Many laboratories have made intensive efforts to develop potent, selective, and orally bioavailable HDAC inhibitors (HDACIs). Novel HDACIs are being developed with the objective of improving potency and selectivity against specific types of cancers or non-cancer diseases. This updated patent review is an attempt to compile the work of various researchers of HDACIs from 2012 to mid 2016, and to enlighten and surprise both newcomers in this field and devoted medicinal chemists. According to the literature research and the writers' own research experience in the discovery of HDAC inhibitors. The inhibitors possessing new chemical scaffolds have attracted immense interest because they have the ability to improve HDAC isoform specificity and pharmaceutical properties. Focus is given to emerging medicinal chemistry principles and insights into the discovery and development of HDAC inhibitors. The development of effective HDACIs is shifting from trial-and-error approaches to sophisticated strategies. Effective profiling technologies will continue to have important utility. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death

    SciTech Connect

    Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki . E-mail: kohnom@net.nagasaki-u.ac.jp

    2006-01-27

    Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated.

  17. Involvement of HDAC1 and the PI3K/PKC signaling pathways in NF-{kappa}B activation by the HDAC inhibitor apicidin

    SciTech Connect

    Kim, Yong Kee . E-mail: yksnbk@kwandong.ac.kr; Seo, Dong-Wan; Kang, Dong-Won; Lee, Hoi Young; Han, Jeung-Whan; Kim, Su-Nam . E-mail: snkim@kist.re.kr

    2006-09-08

    Histone deacetylase (HDAC) inhibitors are appreciated as one of promising anticancer drugs, but they exert differential responses depending on the cell type. We recently reported the critical role of NF-{kappa}B as a modulator in determining cell fate for apoptosis in response to an HDAC inhibitor. In this study, we investigate a possible signaling pathway required for NF-{kappa}B activation in response to the HDAC inhibitor apicidin. Treatment of HeLa cells with apicidin leads to an increase in transcriptional activity of NF-{kappa}B and the expression of its target genes, IL-8 and TNF-{alpha}. TNF-{alpha} expression by apicidin is induced at earlier time points than NF-{kappa}B activation or IL-8 expression. In addition, our data show that the early expression of TNF-{alpha} does not lead to activation of NF-{kappa}B, because disruption of TNF-{alpha} activity by a neutralizing antibody does not affect nuclear translocation of NF-{kappa}B, I{kappa}B{alpha} degradation or reporter gene activation by apicidin. However, this activation of NF-{kappa}B requires the PI3K and PKC signaling pathways, but not ERK or JNK. Furthermore, apicidin activation of NF-{kappa}B seems to result from HDAC1 inhibition, as evidenced by the observation that overexpression of HDAC1, but not HDAC2, 3 or 4, dramatically inhibits NF-{kappa}B reporter gene activity. Collectively, our results suggest that activation of NF-{kappa}B signaling by apicidin requires both the PI3K/PKC signaling pathways and HDAC1, and functions as a critical modulator in determining the cellular effect of apicidin.

  18. Chemistry and biology of chromatin remodeling agents: state of art and future perspectives of HDAC inhibitors.

    PubMed

    Rodriquez, Manuela; Aquino, Maurizio; Bruno, Ines; De Martino, Giovanni; Taddei, Maurizio; Gomez-Paloma, Luigi

    2006-01-01

    Chromatin remodeling is a fundamental phenomenon in the life of eukaryotic cells, bearing implications to numerous physiological and pathological phenomena. This review outlines the chemistry of natural and synthetic agents endowed with the ability to interfere with such biological function, with a particular emphasis on histone deacetylase (HDAC) inhibitors. Other aspects covered in this article comprise structure activity relationships (SAR) and modes of action at molecular level, including the description of crystal structures of enzyme-inhibitor complexes.

  19. A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance

    PubMed Central

    Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

    2017-01-01

    Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future. PMID:28134290

  20. The HDAC Inhibitor Phenylbutyrate Reverses Effects of Neonatal Ventral Hippocampal Lesion in Rats

    PubMed Central

    Sandner, Guy; Host, Lionel; Angst, Marie-Josée; Guiberteau, Thierry; Guignard, Blandine; Zwiller, Jean

    2011-01-01

    Recent evidence suggests that epigenetic mechanisms play a role in psychiatric diseases. In this study, we considered rats with neonatal ventral hippocampal lesions (NVHL) that are currently used for modeling neurodevelopmental aspects of schizophrenia. Contribution of epigenetic regulation to the effects of the lesion was investigated, using a histone deacetylase (HDAC) inhibitor. Lesioned or sham-operated rats were treated with the general HDAC inhibitor phenylbutyrate, which was injected daily from the day after surgery until adulthood. Changes in the volume of the lesion were monitored by magnetic resonance imaging (MRI). Anxiety was analyzed in the Plus Maze Test. Hypersensitivity of the dopaminergic system was evaluated by measuring the locomotor response to apomorphine. An associative conditioning test rewarded with food was used to evaluate learning abilities. The volume of the lesions expanded long after surgery, independently of the treatment, as assessed by MRI. Removal of the ventral hippocampus reduced anxiety, and this remained unchanged when animals were treated with phenylbutyrate. In contrast, NVHL rats’ hypersensitivity to apomorphine and deterioration of the associative learning were reduced by the treatment. Global HDAC activity, which was increased in the prefrontal cortex of lesioned non-treated rats, was found to be reversed by HDAC inhibition. The study provides evidence that chromatin remodeling may be useful for limiting behavioral consequences due to lesioning of the ventral hippocampus at an early age. This represents a novel approach for treating disorders resulting from insults occurring during brain development. PMID:21423460

  1. Lactam-based HDAC inhibitors for anticancer chemotherapy: restoration of RUNX3 by posttranslational modification and epigenetic control.

    PubMed

    Cho, Misun; Choi, Eunhyun; Kim, Jae Hyun; Kim, Hwan; Kim, Hwan Mook; Lee, Jang Ik; Hwang, Ki-Chul; Kim, Hyun-Jung; Han, Gyoonhee

    2014-03-01

    Expression and stability of the tumor suppressor runt-related transcription factor 3 (RUNX3) are regulated by histone deacetylase (HDAC). HDAC inhibition alters epigenetic and posttranslational stability of RUNX3, leading to tumor suppression. However, HDAC inhibitors can nonselectively alter global gene expression through chromatin remodeling. Thus, lactam-based HDAC inhibitors were screened to identify potent protein stabilizers that maintain RUNX3 stability by acetylation. RUNX activity and HDAC inhibition were determined for 111 lactam-based analogues through a cell-based RUNX activation and HDAC inhibition assay. 3-[1-(4-Bromobenzyl)-2-oxo-2,5-dihydro-1H-pyrrol-3-yl]-N-hydroxypropanamide (11-8) significantly increased RUNX3 acetylation and stability with relatively low RUNX3 mRNA expression and HDAC inhibitory activity. This compound showed significant antitumor effects, which were stronger than SAHA, in an MKN28 xenograft model. Thus, we propose a novel strategy, in which HDAC inhibitors serve as antitumor chemotherapeutic agents that selectively target epigenetic regulation and protein stability of RUNX3.

  2. Induction of USP17 by combining BET and HDAC inhibitors in breast cancer cells.

    PubMed

    Borbely, Gabor; Haldosen, Lars-Arne; Dahlman-Wright, Karin; Zhao, Chunyan

    2015-10-20

    Members of the bromodomain and extra-C terminal (BET) domain protein family and the histone deacetylase (HDAC) enzyme family regulate the expression of important oncogenes and tumor suppressor genes. Here we show that the BET inhibitor JQ1 inhibits proliferation and induces apoptosis of both triple negative and estrogen receptor positive breast cancer cells. Consistent with the critical role of histone acetylation in the regulation of gene expression, treatment with JQ1 or the HDAC inhibitor mocetinostat was associated with global changes in gene expression resulting in suppression of genes involved in cell-cycle regulation. Combining JQ1 with mocetinostat, further decreased cell viability. This synergistic effect was associated with increased suppression of genes essential for cell-cycle progression. Furthermore, we detected dramatic increase in the expression of several members of the ubiquitin-specific protease 17 (USP17) family of deubiquitinating enzymes in response to the combination treatment. Increased expression of USP17 enzymes were able to attenuate the Ras/MAPK pathway causing decrease in cell viability, while, siRNA mediated depletion of USP17 significantly decreased cytotoxicity after the combination treatment. In conclusion, our study demonstrates that co-treatment with BET inhibitors and HDAC inhibitors reduces breast cancer cell viability through induction of USP17.

  3. Induction of USP17 by combining BET and HDAC inhibitors in breast cancer cells

    PubMed Central

    Borbely, Gabor; Haldosen, Lars-Arne; Dahlman-Wright, Karin; Zhao, Chunyan

    2015-01-01

    Members of the bromodomain and extra-C terminal (BET) domain protein family and the histone deacetylase (HDAC) enzyme family regulate the expression of important oncogenes and tumor suppressor genes. Here we show that the BET inhibitor JQ1 inhibits proliferation and induces apoptosis of both triple negative and estrogen receptor positive breast cancer cells. Consistent with the critical role of histone acetylation in the regulation of gene expression, treatment with JQ1 or the HDAC inhibitor mocetinostat was associated with global changes in gene expression resulting in suppression of genes involved in cell-cycle regulation. Combining JQ1 with mocetinostat, further decreased cell viability. This synergistic effect was associated with increased suppression of genes essential for cell-cycle progression. Furthermore, we detected dramatic increase in the expression of several members of the ubiquitin–specific protease 17 (USP17) family of deubiquitinating enzymes in response to the combination treatment. Increased expression of USP17 enzymes were able to attenuate the Ras/MAPK pathway causing decrease in cell viability, while, siRNA mediated depletion of USP17 significantly decreased cytotoxicity after the combination treatment. In conclusion, our study demonstrates that co-treatment with BET inhibitors and HDAC inhibitors reduces breast cancer cell viability through induction of USP17. PMID:26378038

  4. HDAC Inhibitor-Mediated Beta-Cell Protection Against Cytokine-Induced Toxicity Is STAT1 Tyr701 Phosphorylation Independent

    PubMed Central

    Dahllöf, Mattias S.; Christensen, Dan P.; Harving, Mette; Wagner, Bridget K.; Mandrup-Poulsen, Thomas

    2015-01-01

    Histone deacetylase (HDAC) inhibition protects pancreatic beta-cells against apoptosis induced by the combination of the proinflammatory cytokines interleukin (IL)-1β and interferon (IFN)-γ. Decreased expression of cell damage-related genes is observed on the transcriptional level upon HDAC inhibition using either IL-1β or IFN-γ alone. Whereas HDAC inhibition has been shown to regulate NFκB-activity, related primarily to IL-1β signaling, it is unknown whether the inhibition of HDACs affect IFN-γ signaling in beta-cells. Further, in non-beta-cells, there is a dispute whether HDAC inhibition regulates IFN-γ signaling at the level of STAT1 Tyr701 phosphorylation. Using different small molecule HDAC inhibitors with varying class selectivity, INS-1E wild type and stable HDAC1-3 knockdown pancreatic INS-1 cell lines, we show that IFN-γ-induced Cxcl9 and iNos expression as well as Cxcl9 and GAS reporter activity were decreased by HDAC inhibition in a STAT1 Tyr701 phosphorylation-independent fashion. In fact, knockdown of HDAC1 increased IFN-γ-induced STAT1 phosphorylation. PMID:25062500

  5. Targeting HDAC with a novel inhibitor effectively reverses paclitaxel resistance in non-small cell lung cancer via multiple mechanisms

    PubMed Central

    Wang, L; Li, H; Ren, Y; Zou, S; Fang, W; Jiang, X; Jia, L; Li, M; Liu, X; Yuan, X; Chen, G; Yang, J; Wu, C

    2016-01-01

    Chemotherapy paclitaxel yields significant reductions in tumor burden in the majority of advanced non-small cell lung cancer (NSCLC) patients. However, acquired resistance limits its clinical use. Here we demonstrated that the histone deacetylase (HDAC) was activated in paclitaxel-resistant NSCLC cells, and its activation promoted proliferation and tumorigenesis of paclitaxel-resistant NSCLC cells in vitro and in vivo. By contrast, knockdown of HDAC1, a primary isoform of HDAC, sensitized resistant cells to paclitaxel in vitro. Furthermore, we observed that overexpression of HDAC1 was associated with the downregulation of p21, a known HDAC target, in advanced NSCLC patients with paclitaxel treatment, and predicted chemotherapy resistance and bad outcome. In addition, we also identified a novel HDACs inhibitor, SNOH-3, which inhibited HDAC expression and activity, induced cell apoptosis, and suppressed cell migration, invasion and angiogenesis. Notably, co-treatment with SNOH-3 and paclitaxel overcome paclitaxel resistance through inhibiting HDAC activity, leading to the induction of apoptosis and suppression of angiogenesis in vitro and in preclinical model. In summary, our data demonstrate a role of HDAC in paclitaxel-resistant NSCLC and provide a promising therapeutic strategy to overcome paclitaxel-acquired resistance. PMID:26794658

  6. HDAC Inhibitors Target Replication Forks to Take a Stab at Cancer | Center for Cancer Research

    Cancer.gov

    The stability and function of many proteins within the cell can be altered with the addition or removal of certain chemical groups, including acetyl groups. Therefore, the enzymes that regulate these modifications have an important impact on the cell. One class of such enzymes—histone deacetylases, or HDACs—has been implicated in cancer and has become a target for cancer therapy. One HDAC inhibitor, called SAHA, has been approved for use against cutaneous T-cell lymphoma, and more than 60 ongoing clinical trials are continuing to test this class of drugs in various forms of cancer. However, the mechanisms by which SAHA and other HDAC inhibitors undermine the viability of tumor cells are not completely understood.

  7. Targeting prostate cancer with compounds possessing dual activity as androgen receptor antagonists and HDAC6 inhibitors.

    PubMed

    Jadhavar, Pradeep S; Ramachandran, Sreekanth A; Riquelme, Eduardo; Gupta, Ashu; Quinn, Kevin P; Shivakumar, Devleena; Ray, Soumya; Zende, Dnyaneshwar; Nayak, Anjan K; Miglani, Sandeep K; Sathe, Balaji D; Raja, Mohd; Farias, Olivia; Alfaro, Ivan; Belmar, Sebastián; Guerrero, Javier; Bernales, Sebastián; Chakravarty, Sarvajit; Hung, David T; Lindquist, Jeffrey N; Rai, Roopa

    2016-11-01

    While enzalutamide and abiraterone are approved for treatment of metastatic castration-resistant prostate cancer (mCRPC), approximately 20-40% of patients have no response to these agents. It has been stipulated that the lack of response and the development of secondary resistance to these drugs may be due to the presence of AR splice variants. HDAC6 has a role in regulating the androgen receptor (AR) by modulating heat shock protein 90 (Hsp90) acetylation, which controls the nuclear localization and activation of the AR in androgen-dependent and independent scenarios. With dual-acting AR-HDAC6 inhibitors it should be possible to target patients who don't respond to enzalutamide. Herein, we describe the design, synthesis and biological evaluation of dual-acting compounds which target AR and are also specific towards HDAC6. Our efforts led to compound 10 which was found to have potent dual activity (HDAC6 IC50=0.0356μM and AR binding IC50=<0.03μM). Compound 10 was further evaluated for antagonist and other cell-based activities, in vitro stability and pharmacokinetics.

  8. HDAC and Proteasome Inhibitors Synergize to Activate Pro-Apoptotic Factors in Synovial Sarcoma

    PubMed Central

    Barrott, Jared J.; Yao, Ren Jie; Poulin, Neal M.; Brodin, Bertha A.; Jones, Kevin B.; Underhill, T. Michael; Nielsen, Torsten O.

    2017-01-01

    Conventional cytotoxic therapies for synovial sarcoma provide limited benefit, and no drugs specifically targeting its driving SS18-SSX fusion oncoprotein are currently available. Patients remain at high risk for early and late metastasis. A high-throughput drug screen consisting of over 900 tool compounds and epigenetic modifiers, representing over 100 drug classes, was undertaken in a panel of synovial sarcoma cell lines to uncover novel sensitizing agents and targetable pathways. Top scoring drug categories were found to be HDAC inhibitors and proteasomal targeting agents. We find that the HDAC inhibitor quisinostat disrupts the SS18-SSX driving protein complex, thereby reestablishing expression of EGR1 and CDKN2A tumor suppressors. In combination with proteasome inhibition, HDAC inhibitors synergize to decrease cell viability and elicit apoptosis. Quisinostat inhibits aggresome formation in response to proteasome inhibition, and combination treatment leads to elevated endoplasmic reticulum stress, activation of pro-apoptotic effector proteins BIM and BIK, phosphorylation of BCL-2, increased levels of reactive oxygen species, and suppression of tumor growth in a murine model of synovial sarcoma. This study identifies and provides mechanistic support for a particular susceptibility of synovial sarcoma to the combination of quisinostat and proteasome inhibition. PMID:28056055

  9. Combination of sapacitabine and HDAC inhibitors stimulates cell death in AML and other tumour types.

    PubMed

    Green, S R; Choudhary, A K; Fleming, I N

    2010-10-26

    Alternative treatments are needed for elderly patients with acute myeloid leukaemia, as the disease prognosis is poor and the current treatment is unsuitable for many patients. In this study, we investigated whether combining the nucleoside analogue sapacitabine with histone deacetylase (HDAC) inhibitors could be an effective treatment. Synergy and mode-of-action analysis were studied in cultured cell lines and the efficacy of the combination was confirmed in a xenograft model. CNDAC (1-(2-C-cyano-2-deoxy-β-D-arabino-pentofuranosyl)-cytosine), the active component of sapacitabine, synergised with vorinostat in cell lines derived from a range of tumour types. Synergy was not dependent on a specific sequence of drug administration and was also observed when CNDAC was combined with an alternative HDAC inhibitor, valproate. Flow cytometry and western blot analysis confirmed that the combination induced a significant increase in apoptosis. Mode-of-action analysis detected changes in Bcl-xl, Mcl-1, Noxa, Bid and Bim, which are all regulators of the apoptotic process. The sapacitabine/vorinostat combination demonstrated significant benefit compared with the single-agent treatments in an MV4-11 xenograft, in the absence of any observed toxicity. Sapacitabine and HDAC inhibitors are an effective drug combination that is worthy of clinical exploration.

  10. Kinetic and structural insights into the binding of histone deacetylase 1 and 2 (HDAC1, 2) inhibitors.

    PubMed

    Wagner, Florence F; Weïwer, Michel; Steinbacher, Stefan; Schomburg, Adrian; Reinemer, Peter; Gale, Jennifer P; Campbell, Arthur J; Fisher, Stewart L; Zhao, Wen-Ning; Reis, Surya A; Hennig, Krista M; Thomas, Méryl; Müller, Peter; Jefson, Martin R; Fass, Daniel M; Haggarty, Stephen J; Zhang, Yan-Ling; Holson, Edward B

    2016-09-15

    The structure-activity and structure-kinetic relationships of a series of novel and selective ortho-aminoanilide inhibitors of histone deacetylases (HDACs) 1 and 2 are described. Different kinetic and thermodynamic selectivity profiles were obtained by varying the moiety occupying an 11Å channel leading to the Zn(2+) catalytic pocket of HDACs 1 and 2, two paralogs with a high degree of structural similarity. The design of these novel inhibitors was informed by two ligand-bound crystal structures of truncated hHDAC2. BRD4884 and BRD7232 possess kinetic selectivity for HDAC1 versus HDAC2. We demonstrate that the binding kinetics of HDAC inhibitors can be tuned for individual isoforms in order to modulate target residence time while retaining functional activity and increased histone H4K12 and H3K9 acetylation in primary mouse neuronal cell culture assays. These chromatin modifiers, with tuned binding kinetic profiles, can be used to define the relation between target engagement requirements and the pharmacodynamic response of HDACs in different disease applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Cell-based multi-substrate assay coupled to UHPLC-ESI-MS/MS for a quick identification of class-specific HDAC inhibitors.

    PubMed

    Zwick, Vincent; Simões-Pires, Claudia; Cuendet, Muriel

    2016-01-01

    Histone deacetylases (HDAC) are involved in several diseases including cancer, cardiovascular and neurodegenerative disorders, and the search for inhibitors is a current topic in drug discovery. Four HDAC inhibitors have already been approved by the FDA for cancer therapy and others are under clinical studies. However, the clinical utility of some of them is limited because of unfavorable toxicities associated with their broad range of HDAC inhibitory effects. Toxicity could be decreased by using HDAC inhibitors with improved specificity. To date, the most popular screening assays are based on fluorescence-labeled substrates incubated with an enzymatic source (cells extracts or recombinant isoforms). Here, we describe a high-throughput cell-based UHPLC-ESI-MS/MS assay able to rapidly predict activity against HDAC1 and HDAC6 in a cell environment. This method is predicted to be a useful tool to accelerate the search for class-selective HDAC inhibitors in drug discovery.

  12. Identification of a better Homo sapiens Class II HDAC inhibitor through binding energy calculations and descriptor analysis.

    PubMed

    Tambunan, Usman Sumo Friend; Wulandari, Evi Kristin

    2010-10-15

    Human papillomaviruses (HPVs) are the most common on sexually transmitted viruses in the world. HPVs are responsible for a large spectrum of deseases, both benign and malignant. The certain types of HPV are involved in the development of cervical cancer. In attemps to find additional drugs in the treatment of cervical cancer, inhibitors of the histone deacetylases (HDAC) have received much attention due to their low cytotoxic profiles and the E6/E7 oncogene function of human papilomavirus can be completely by passed by HDAC inhibition. The histone deacetylase inhibitors can induce growth arrest, differentiation and apoptosis of cancer cells. HDAC class I and class II are considered the main targets for cancer. Therefore, the six HDACs class II was modeled and about two inhibitors (SAHA and TSA) were docked using AutoDock4.2, to each of the inhibitor in order to identify the pharmacological properties. Based on the results of docking, SAHA and TSA were able to bind with zinc ion in HDACs models as a drug target. SAHA was satisfied almost all the properties i.e., binding affinity, the Drug-Likeness value and Drug Score with 70% oral bioavailability and the carbonyl group of these compound fits well into the active site of the target where the zinc is present. Hence, SAHA could be developed as potential inhibitors of class II HDACs and valuable cervical cancer drug candidate.

  13. The anticancer effects of HDAC inhibitors require the immune system

    PubMed Central

    West, Alison C; Smyth, Mark J; Johnstone, Ricky W

    2014-01-01

    Histone deacetylase inhibitors (HDACis) are known to exert immunomodulatory effects. We have recently demonstrated that the therapeutic efficacy of HDACis against aggressive B-cell lymphoma and colon carcinoma relies on a functional immune system, in particular on the production of interferon γ (IFNγ). Our findings provide a rationale for the combination of HDACis with immunotherapeutic agents in the clinic. PMID:24701376

  14. The Role of HDACs Inhibitors in Childhood and Adolescence Acute Leukemias

    PubMed Central

    Masetti, Riccardo; Serravalle, Salvatore; Biagi, Carlotta; Pession, Andrea

    2011-01-01

    Acute leukemia is the most common type of childhood and adolescence cancer, characterized by clonal proliferation of variably differentiated myeloid or lymphoid precursors. Recent insights into the molecular pathogenesis of leukemia have shown that epigenetic modifications, such as deacetylation of histones and DNA methylation, play crucial roles in leukemogenesis, by transcriptional silencing of critical genes. Histone deacetylases (HDACs) are potential targets in the treatment of leukaemia, and, as a consequence, inhibitors of HDACs (HDIs) are being studied for therapeutic purposes. HDIs promote or enhance several different anticancer mechanisms, such as apoptosis, cell cycle arrest, and cellular differentiation and, therefore, are in evidence as promising treatment for children and adolescents with acute leukemia, in monotherapy or in association with other anticancer drugs. Here we review the main preclinical and clinical studies regarding the use of HDIs in treating childhood and adolescence leukemia. PMID:21318168

  15. Modulation of Activity Profiles for Largazole-Based HDAC Inhibitors through Alteration of Prodrug Properties

    PubMed Central

    2014-01-01

    Largazole is a potent and class I-selective histone deacetylase (HDAC) inhibitor purified from marine cyanobacteria and was demonstrated to possess antitumor activity. Largazole employs a unique prodrug strategy, via a thioester moiety, to liberate the bioactive species largazole thiol. Here we report alternate prodrug strategies to modulate the pharmacokinetic and pharmacodynamics profiles of new largazole-based compounds. The in vitro effects of largazole analogues on cancer cell proliferation and enzymatic activities of purified HDACs were comparable to the natural product. However, in vitro and in vivo histone hyperacetylation in HCT116 cells and implanted tumors, respectively, showed differences, particularly in the onset of action and oral bioavailability. These results indicate that, by employing a different approach to disguise the “warhead” moiety, the functional consequence of these prodrugs can be significantly modulated. Our data corroborate the role of the pharmacokinetic properties of this class of compounds to elicit the desired and timely functional response. PMID:25147612

  16. Thiol-Based Potent and Selective HDAC6 Inhibitors Promote Tubulin Acetylation and T-Regulatory Cell Suppressive Function.

    PubMed

    Segretti, Mariana C F; Vallerini, Gian Paolo; Brochier, Camille; Langley, Brett; Wang, Liqing; Hancock, Wayne W; Kozikowski, Alan P

    2015-11-12

    Several new mercaptoacetamides were synthesized and studied as HDAC6 inhibitors. One compound, 2b, bearing an aminoquinoline cap group, was found to show 1.3 nM potency at HDAC6, with >3000-fold selectivity over HDAC1. 2b also showed excellent efficacy at increasing tubulin acetylation in rat primary cortical cultures, inducing a 10-fold increase in acetylated tubulin at 1 μM. To assess possible therapeutic effects, compounds were assayed for their ability to increase T-regulatory (Treg) suppressive function. Some but not all of the compounds increased Treg function, and thereby decreased conventional T cell activation and proliferation in vitro.

  17. Thiol-Based Potent and Selective HDAC6 Inhibitors Promote Tubulin Acetylation and T-Regulatory Cell Suppressive Function

    PubMed Central

    2015-01-01

    Several new mercaptoacetamides were synthesized and studied as HDAC6 inhibitors. One compound, 2b, bearing an aminoquinoline cap group, was found to show 1.3 nM potency at HDAC6, with >3000-fold selectivity over HDAC1. 2b also showed excellent efficacy at increasing tubulin acetylation in rat primary cortical cultures, inducing a 10-fold increase in acetylated tubulin at 1 μM. To assess possible therapeutic effects, compounds were assayed for their ability to increase T-regulatory (Treg) suppressive function. Some but not all of the compounds increased Treg function, and thereby decreased conventional T cell activation and proliferation in vitro. PMID:26617971

  18. HDAC inhibitors induce global changes in histone lysine and arginine methylation and alter expression of lysine demethylases.

    PubMed

    Lillico, Ryan; Sobral, Marina Gomez; Stesco, Nicholas; Lakowski, Ted M

    2016-02-05

    Histone deacetylase (HDAC) inhibitors are cancer treatments that inhibit the removal of the epigenetic modification acetyllysine on histones, resulting in altered gene expression. Such changes in expression may influence other histone epigenetic modifications. We describe a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify lysine acetylation and methylation and arginine methylation on histones extracted from cultured cells treated with HDAC inhibitors. The HDAC inhibitors vorinostat, mocetinostat and entinostat induced 400-600% hyperacetylation in HEK 293 and K562 cells. All HDAC inhibitors decreased histone methylarginines in HEK 293 cells but entinostat produced dose dependent reductions in asymmetric dimethylarginine, not observed in K562 cells. Vorinostat produced increases in histone lysine methylation and decreased expression of some lysine demethylases (KDM), measured by quantitative PCR. Entinostat had variable effects on lysine methylation and decreased expression of some KDM while increasing expression of others. Mocetinostat produced dose dependent increases in histone lysine methylation by LC-MS/MS. This was corroborated with a multiplex colorimetric assay showing increases in histone H3 lysine 4, 9, 27, 36 and 79 methylation. Increases in lysine methylation were correlated with dose dependent decreases in the expression of seven KDM. Mocetinostat functions as an HDAC inhibitor and a de facto KDM inhibitor. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. miR-2861 as novel HDAC5 inhibitor in CHO cells enhances productivity while maintaining product quality.

    PubMed

    Fischer, Simon; Paul, Albert Jesuran; Wagner, Andreas; Mathias, Sven; Geiss, Melanie; Schandock, Franziska; Domnowski, Martin; Zimmermann, Jörg; Handrick, René; Hesse, Friedemann; Otte, Kerstin

    2015-10-01

    Histone deacetylase (HDAC) inhibitors have been exploited for years to improve recombinant protein expression in mammalian production cells. However, global HDAC inhibition is associated with negative effects on various cellular processes. microRNAs (miRNAs) have been shown to regulate gene expression in almost all eukaryotic cell types by controlling entire cellular pathways. Since miRNAs recently have gained much attention as next-generation cell engineering tool to improve Chinese hamster ovary (CHO) cell factories, we were interested if miRNAs are able to specifically repress HDAC expression in CHO cells to circumvent limitations of unspecific HDAC inhibition. We discovered a novel miRNA in CHO cells, miR-2861, which was shown to enhance productivity in various recombinant CHO cell lines. Furthermore, we demonstrate that miR-2861 might post-transcriptionally regulate HDAC5 in CHO cells. Intriguingly, siRNA-mediated HDAC5 suppression could be demonstrated to phenocopy pro-productive effects of miR-2861 in CHO cells. This supports the notion that miRNA-induced inhibition of HDAC5 may contribute to productivity enhancing effects of miR-2861. Furthermore, since product quality is fundamental to safety and functionality of biologics, we examined the effect of HDAC inhibition on critical product quality attributes. In contrast to unspecific HDAC inhibition using VPA, enforced expression of miR-2861 did not negatively influence antibody aggregation or N-glycosylation. Our findings highlight the superiority of miRNA-mediated inhibition of specific HDACs and present miR-2861 as novel cell engineering tool for improving CHO manufacturing cells.

  20. HDAC inhibitors: roles of DNA damage and repair.

    PubMed

    Robert, Carine; Rassool, Feyruz V

    2012-01-01

    Histone deacetylase inhibitors (HDACis) increase gene expression through induction of histone acetylation. However, it remains unclear whether specific gene expression changes determine the apoptotic response following HDACis administration. Herein, we discuss evidence that HDACis trigger in cancer and leukemia cells not only widespread histone acetylation but also actual increases in reactive oxygen species (ROS) and DNA damage that are further increased following treatment with DNA-damaging chemotherapies. While the origins of ROS production are not completely understood, mechanisms, including inflammation and altered antioxidant signaling, have been reported. While the generation of ROS is an explanation, at least in part, for the source of DNA damage observed with HDACi treatment, DNA damage can also be independently induced by changes in the DNA repair activity and chromatin remodeling factors. Recent development of sirtuin inhibitors (SIRTis) has shown that, similar to HDACis, these drugs induce increases in ROS and DNA damage used singly, or in combination with HDACis and other drugs. Thus, induction of apoptosis by HDACis/SIRTis may result through oxidative stress and DNA damage mechanisms in addition to direct activation of apoptosis-inducing genes. Nevertheless, while DNA damage and stress responses could be of interest as markers for clinical responses, they have yet to be validated as markers for responses to HDACi treatment in clinical trials, alone, and in combination.

  1. Proteomic Analysis of HDAC3 Selective Inhibitor in the Regulation of Inflammatory Response of Primary Microglia

    PubMed Central

    Zhao, Qiuchen; Zhang, He; Chen, Yanting; Yuan, Zengqiang; Xu, Yun

    2017-01-01

    HDAC3 has been shown to regulate inflammation. However, the role of HDAC3 in primary microglia is largely unknown. RGFP966 is a newly discovered selective HDAC3 inhibitor. In this study, we used protein mass spectrometry to analyze protein alterations in LPS-treated primary microglia with the application of RGFP966. Generally, about 2000 proteins were studied. 168 of 444 (37.8%) LPS-induced proteins were significantly reduced with the treatment of RGFP966, which mainly concentrated on Toll-like receptor signaling pathway. In this regard, we selected Toll-like receptor 2 (TLR2), TLR3, TLR6, MAPK p38, CD36, and spleen tyrosine kinase (SYK) for further validation and found that they were all significantly upregulated after LPS stimulation and downregulated in the presence of RGFP966. Additionally, RGFP966 inhibited supernatant tumor necrosis factor (TNF)-α and Interleukin 6 (IL-6) concentrations. Activation of STAT3 and STAT5 was partially blocked by RGFP966 at 2 h after LPS-stimulation. The fluorescence intensity of CD16/32 was significantly decreased in LPS + RGFP966-treated group. In conclusion, our data provided a hint that RGFP966 may be a potential therapeutic medication combating microglia activation and inflammatory response in central nervous system, which was probably related to its repressive impacts on TLR signaling pathways and STAT3/STAT5 pathways. PMID:28293439

  2. 4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide - A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation.

    PubMed

    Mahal, Katharina; Kahlen, Philip; Biersack, Bernhard; Schobert, Rainer

    2015-08-15

    Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazoles bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Use of the nitrile oxide cycloaddition (NOC) reaction for molecular probe generation: a new class of enzyme selective histone deacetylase inhibitors (HDACIs) showing picomolar activity at HDAC6.

    PubMed

    Kozikowski, Alan P; Tapadar, Subhasish; Luchini, Doris N; Kim, Ki Hwan; Billadeau, Daniel D

    2008-08-14

    A series of hydroxamate based HDAC inhibitors containing a phenylisoxazole as the CAP group has been synthesized using nitrile oxide cycloaddition chemistry. An HDAC6 selective inhibitor having a potency of approximately 2 picomolar was identified. Some of the compounds were examined for their ability to block pancreatic cancer cell growth and found to be about 10-fold more potent than SAHA. This research provides valuable, new molecular probes for use in exploring HDAC biology.

  4. HDAC2 blockade by nitric oxide and histone deacetylase inhibitors reveals a common target in Duchenne muscular dystrophy treatment

    PubMed Central

    Colussi, Claudia; Mozzetta, Chiara; Gurtner, Aymone; Illi, Barbara; Rosati, Jessica; Straino, Stefania; Ragone, Gianluca; Pescatori, Mario; Zaccagnini, Germana; Antonini, Annalisa; Minetti, Giulia; Martelli, Fabio; Piaggio, Giulia; Gallinari, Paola; Steinkuhler, Christian; Clementi, Emilio; Dell'Aversana, Carmela; Altucci, Lucia; Mai, Antonello; Capogrossi, Maurizio C.; Puri, Pier Lorenzo; Gaetano, Carlo

    2008-01-01

    The overlapping histological and biochemical features underlying the beneficial effect of deacetylase inhibitors and NO donors in dystrophic muscles suggest an unanticipated molecular link among dystrophin, NO signaling, and the histone deacetylases (HDACs). Higher global deacetylase activity and selective increased expression of the class I histone deacetylase HDAC2 were detected in muscles of dystrophin-deficient MDX mice. In vitro and in vivo siRNA-mediated down-regulation of HDAC2 in dystrophic muscles was sufficient to replicate the morphological and functional benefits observed with deacetylase inhibitors and NO donors. We found that restoration of NO signaling in vivo, by adenoviral-mediated expression of a constitutively active endothelial NOS mutant in MDX muscles, and in vitro, by exposing MDX-derived satellite cells to NO donors, resulted in HDAC2 blockade by cysteine S-nitrosylation. These data reveal a special contribution of HDAC2 in the pathogenesis of Duchenne muscular dystrophy and indicate that HDAC2 inhibition by NO-dependent S-nitrosylation is important for the therapeutic response to NO donors in MDX mice. They also define a common target for independent pharmacological interventions in the treatment of Duchenne muscular dystrophy. PMID:19047631

  5. HDAC2 blockade by nitric oxide and histone deacetylase inhibitors reveals a common target in Duchenne muscular dystrophy treatment.

    PubMed

    Colussi, Claudia; Mozzetta, Chiara; Gurtner, Aymone; Illi, Barbara; Rosati, Jessica; Straino, Stefania; Ragone, Gianluca; Pescatori, Mario; Zaccagnini, Germana; Antonini, Annalisa; Minetti, Giulia; Martelli, Fabio; Piaggio, Giulia; Gallinari, Paola; Steinkuhler, Christian; Steinkulher, Christian; Clementi, Emilio; Dell'Aversana, Carmela; Altucci, Lucia; Mai, Antonello; Capogrossi, Maurizio C; Puri, Pier Lorenzo; Gaetano, Carlo

    2008-12-09

    The overlapping histological and biochemical features underlying the beneficial effect of deacetylase inhibitors and NO donors in dystrophic muscles suggest an unanticipated molecular link among dystrophin, NO signaling, and the histone deacetylases (HDACs). Higher global deacetylase activity and selective increased expression of the class I histone deacetylase HDAC2 were detected in muscles of dystrophin-deficient MDX mice. In vitro and in vivo siRNA-mediated down-regulation of HDAC2 in dystrophic muscles was sufficient to replicate the morphological and functional benefits observed with deacetylase inhibitors and NO donors. We found that restoration of NO signaling in vivo, by adenoviral-mediated expression of a constitutively active endothelial NOS mutant in MDX muscles, and in vitro, by exposing MDX-derived satellite cells to NO donors, resulted in HDAC2 blockade by cysteine S-nitrosylation. These data reveal a special contribution of HDAC2 in the pathogenesis of Duchenne muscular dystrophy and indicate that HDAC2 inhibition by NO-dependent S-nitrosylation is important for the therapeutic response to NO donors in MDX mice. They also define a common target for independent pharmacological interventions in the treatment of Duchenne muscular dystrophy.

  6. Resveratrol as a Pan-HDAC Inhibitor Alters the Acetylation Status of Jistone Proteins in Human-Derived Hepatoblastoma Cells

    PubMed Central

    Böcker, Alexander; Busch, Christian; Weiland, Timo; Noor, Seema; Leischner, Christian; Schleicher, Sabine; Mayer, Mascha; Weiss, Thomas S.; Bischoff, Stephan C.; Lauer, Ulrich M.; Bitzer, Michael

    2013-01-01

    The polyphenolic alcohol resveratrol has demonstrated promising activities for the prevention and treatment of cancer. Different modes of action have been described for resveratrol including the activation of sirtuins, which represent the class III histone deacetylases (HDACs). However, little is known about the activity of resveratrol on the classical HDACs of class I, II and IV, although these classes are involved in cancer development or progression and inhibitors of HDACs (HDACi) are currently under investigation as promising novel anticancer drugs. We could show by in silico docking studies that resveratrol has the chemical structure to inhibit the activity of different human HDAC enzymes. In vitro analyses of overall HDAC inhibition and a detailed HDAC profiling showed that resveratrol inhibited all eleven human HDACs of class I, II and IV in a dose-dependent manner. Transferring this molecular mechanism into cancer therapy strategies, resveratrol treatment was analyzed on solid tumor cell lines. Despite the fact that hepatocellular carcinoma (HCC) is known to be particularly resistant against conventional chemotherapeutics, treatment of HCC with established HDACi already has shown promising results. Testing of resveratrol on hepatoma cell lines HepG2, Hep3B and HuH7 revealed a dose-dependent antiproliferative effect on all cell lines. Interestingly, only for HepG2 cells a specific inhibition of HDACs and in turn a histone hyperacetylation caused by resveratrol was detected. Additional testing of human blood samples demonstrated a HDACi activity by resveratrol ex vivo. Concluding toxicity studies showed that primary human hepatocytes tolerated resveratrol, whereas in vivo chicken embryotoxicity assays demonstrated severe toxicity at high concentrations. Taken together, this novel pan-HDACi activity opens up a new perspective of resveratrol for cancer therapy alone or in combination with other chemotherapeutics. Moreover, resveratrol may serve as a lead

  7. Late-Stage C-H Coupling Enables Rapid Identification of HDAC Inhibitors: Synthesis and Evaluation of NCH-31 Analogues.

    PubMed

    Sekizawa, Hiromi; Amaike, Kazuma; Itoh, Yukihiro; Suzuki, Takayoshi; Itami, Kenichiro; Yamaguchi, Junichiro

    2014-05-08

    We previously reported the discovery of NCH-31, a potent histone deacetylase (HDAC) inhibitor. By utilizing our C-H coupling reaction, we rapidly synthesized 16 analogues (IYS-1 through IYS-15 and IYS-Me) of NCH-31 with different aryl groups at the C4-position of 2-aminothiazole core of NCH-31. Subsequent biological testing of these derivatives revealed that 3-fluorophenyl (IYS-10) and 4-fluorophenyl (IYS-15) derivatives act as potent pan-HDAC inhibitor. Additionally, 4-methylphenyl (IYS-1) and 3-fluoro-4-methylphenyl (IYS-14) derivatives acted as HDAC6-insensitive inhibitors. The present work clearly shows the power of the late-stage C-H coupling approach to rapidly identify novel and highly active/selective biofunctional molecules.

  8. Late-Stage C–H Coupling Enables Rapid Identification of HDAC Inhibitors: Synthesis and Evaluation of NCH-31 Analogues

    PubMed Central

    2014-01-01

    We previously reported the discovery of NCH-31, a potent histone deacetylase (HDAC) inhibitor. By utilizing our C–H coupling reaction, we rapidly synthesized 16 analogues (IYS-1 through IYS-15 and IYS-Me) of NCH-31 with different aryl groups at the C4-position of 2-aminothiazole core of NCH-31. Subsequent biological testing of these derivatives revealed that 3-fluorophenyl (IYS-10) and 4-fluorophenyl (IYS-15) derivatives act as potent pan-HDAC inhibitor. Additionally, 4-methylphenyl (IYS-1) and 3-fluoro-4-methylphenyl (IYS-14) derivatives acted as HDAC6-insensitive inhibitors. The present work clearly shows the power of the late-stage C–H coupling approach to rapidly identify novel and highly active/selective biofunctional molecules. PMID:24900884

  9. Probing the bioactive conformation of an archetypal natural product HDAC inhibitor with conformationally homogeneous triazole-modified cyclic tetrapeptides.

    PubMed

    Horne, W Seth; Olsen, Christian A; Beierle, John M; Montero, Ana; Ghadiri, M Reza

    2009-01-01

    Fooling enzymes with mock amides: Analogues of apicidin, a cyclic-tetrapeptide inhibitor of histone deacetylase (HDAC), were designed with a 1,4- or 1,5-disubstituted 1,2,3-triazole in place of a backbone amide bond to fix the bond in question in either a trans-like or a cis-like configuration. Thus, the binding affinity of distinct peptide conformations (see picture) could be probed. One analogue proved in some cases to be superior to apicidin as an HDAC inhibitor.

  10. Unexpected Biotransformation of the HDAC Inhibitor Vorinostat Yields Aniline-Containing Fungal Metabolites.

    PubMed

    Adpressa, Donovon A; Stalheim, Kayla J; Proteau, Philip J; Loesgen, Sandra

    2017-07-21

    The diversity of genetically encoded small molecules produced by filamentous fungi remains largely unexplored, which makes these fungi an attractive source for the discovery of new compounds. However, accessing their full chemical repertoire under common laboratory culture conditions is a challenge. Epigenetic manipulation of gene expression has become a well-established tool for overcoming this obstacle. Here, we report that perturbation of the endophytic ascomycete Chalara sp. 6661, producer of the isofusidienol class of antibiotics, with the HDAC inhibitor vorinostat resulted in the production of four new modified xanthones. The structures of chalanilines A (1) and B (2) and adenosine-coupled xanthones A (3) and B (4) were determined by extensive NMR spectroscopic analyses, and the bioactivities of 1-4 were tested in antibiotic and cytotoxicity assays. Incorporation studies with deuterium-labeled vorinostat indicate that the aniline moiety in chalalanine A is derived from vorinostat itself. Our study shows that Chalara sp. is able to metabolize the HDAC inhibitor vorinostat to release aniline. This is a rare report of fungal biotransformation of the popular epigenetic modifier vorinostat into aniline-containing polyketides.

  11. Structure-Based Design and Synthesis of Novel Inhibitors Targeting HDAC8 from Schistosoma mansoni for the Treatment of Schistosomiasis.

    PubMed

    Heimburg, Tino; Chakrabarti, Alokta; Lancelot, Julien; Marek, Martin; Melesina, Jelena; Hauser, Alexander-Thomas; Shaik, Tajith B; Duclaud, Sylvie; Robaa, Dina; Erdmann, Frank; Schmidt, Matthias; Romier, Christophe; Pierce, Raymond J; Jung, Manfred; Sippl, Wolfgang

    2016-03-24

    Schistosomiasis is a major neglected parasitic disease that affects more than 265 million people worldwide and for which the control strategy consists of mass treatment with the only available drug, praziquantel. In this study, a series of new benzohydroxamates were prepared as potent inhibitors of Schistosoma mansoni histone deacetylase 8 (smHDAC8). Crystallographic analysis provided insights into the inhibition mode of smHDAC8 activity by these 3-amidobenzohydroxamates. The newly designed inhibitors were evaluated in screens for enzyme inhibitory activity against schistosome and human HDACs. Twenty-seven compounds were found to be active in the nanomolar range, and some of them showed selectivity toward smHDAC8 over the major human HDACs (1 and 6). The active benzohydroxamates were additionally screened for lethality against the schistosome larval stage using a fluorescence-based assay. Four of these showed significant dose-dependent killing of the schistosome larvae and markedly impaired egg laying of adult worm pairs maintained in culture.

  12. Histone deacetylase inhibitor BML-210 induces growth inhibition and apoptosis and regulates HDAC and DAPC complex expression levels in cervical cancer cells.

    PubMed

    Borutinskaite, Veronika V; Magnusson, Karl-Eric; Navakauskiene, Ruta

    2012-12-01

    Histone deacetylase inhibitors (HDACIs) represent a new class of targeted anti-cancer agents and different other diseases, like muscular disorders. A number of studies have shown that extracellular signal-activated kinases can target chromatin-modifying complexes directly and regulate their function. The molecular connection between the dystrophin-associated protein complex (DAPC) and chromatin has been described, by showing that NO signaling regulates histone deacetylase (HDAC) activity and influences gene expression in different cell types. In present study, we investigated HDACs changes in HeLa cells undergoing growth inhibition and apoptosis, caused by HDACI BML-210 and retinoic acid (ATRA). Cell cycle analysis indicated that HeLa cell treatment with 20 and 30 μM concentration of BML-210 increased the proportion of cells in G0/G1 phase, and caused accumulation in subG1, indicating that the cells are undergoing apoptosis. We determined down-regulation of HDAC 1-5 and 7 after treatment with BML-210. Also, we demonstrated expression of different isoforms of alpha-dystrobrevin (α-DB) and other components of DAPC such as syntrophin, dystrophin, beta-dystrobrevin (β-DB) and NOS in HeLa cells after treatments. We determined changes in protein expression level of dystrophin, NOS1, α- and β-DB and in subcellular localization of α-DB after treatments with BML-210 and ATRA. In conclusion, these results suggest that HDACI BML-210 can inhibit cell growth and induce apoptosis in cervical cancer cells, what correlates with down-regulation of HDAC class I and II and changes in the DAPC expression levels. This can be important for identifying target proteins in DAPC signaling to HDACs, as a target of pharmacological intervention for treatment of muscular dystrophies and other diseases.

  13. 4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide – A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation

    SciTech Connect

    Mahal, Katharina; Kahlen, Philip; Biersack, Bernhard; Schobert, Rainer

    2015-08-15

    Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazoles bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. - Graphical abstract: A novel histone deacetylase inhibitor with pleiotropic anticancer effects. - Highlights: • Etacrox is a new HDACi with cytotoxic, antiangiogenic and antiinvasive activity. • Etacrox causes aberrant cancer cell signalling and cytoskeletal reorganisation. • Pro-metastatic and angiogenic matrix metalloproteinases are inhibited by etacrox. • Etacrox impairs blood vessel maturation in vivo and cancer cell

  14. Cross metathesis with hydroxamate and benzamide BOC-protected alkenes to access HDAC inhibitors and their biological evaluation highlighted intrinsic activity of BOC-protected dihydroxamates.

    PubMed

    Zwick, Vincent; Nurisso, Alessandra; Simões-Pires, Claudia; Bouchet, Samuel; Martinet, Nadine; Lehotzky, Attila; Ovadi, Judit; Cuendet, Muriel; Blanquart, Christophe; Bertrand, Philippe

    2016-01-01

    Conditions for the metathesis of alkenes in the convergent synthesis of HDAC inhibitors have been improved by continuous catalyst flow injection in the reaction media. Intermediate and target compounds obtained were tested for their ability to induce HDAC inhibition and tubulin acetylation, revealing the key role of the tert-butyloxycarbonyl (BOC) group for more HDAC6 selectivity. Molecular modelling added rationale for this BOC effect.

  15. Design, synthesis and biological evaluation of saccharin-based N-hydroxybenzamides as histone deacetylases (HDACs) inhibitors.

    PubMed

    Fu, Huansheng; Han, Leiqiang; Hou, Xuben; Dun, Yanyan; Wang, Lei; Gong, Xiaowei; Fang, Hao

    2015-09-01

    We report the development of a novel series of saccharin-based N-hydroxybenzamides as histone deacetylases inhibitors. Among them, 6 j exhibited potent HDACs inhibitory activity against Hela nuclear extract. Further biological evaluation found 6 i showed similar antiproliferative activities in vitro compared with the approved SAHA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Methylseleninic acid inhibits HDAC activity in diffuse large B-cell lymphoma cell lines.

    PubMed

    Kassam, Shireen; Goenaga-Infante, Heidi; Maharaj, Lenushka; Hiley, Crispin T; Juliger, Simone; Joel, Simon P

    2011-09-01

    Selenium is a trace element that is fundamental to human health. Research has mainly focussed on its role in cancer prevention, but recent evidence supports its role in established cancer, with high concentrations inducing tumour cell death and non-toxic concentrations sensitising cells to chemotherapy. However, the precise mechanism of selenium action is not clear. The effect of methylseleninic acid (MSA), an organic selenium compound, on histone deacetylase (HDAC) activity in diffuse large B-cell lymphoma cell lines is reported here. Lymphoma cell lines were exposed to MSA under normoxic and hypoxic conditions. Protein expression was determined by western blotting, HDAC activity and VEGF concentration by fluorimetric and electrochemiluminescence assays, respectively, and intracellular selenium metabolites quantified by mass spectrometry. MSA inhibited HDAC activity, which resulted in the acetylation of histone H3 and α-tubulin. However, cellular metabolism of MSA to methylselenol was required for this effect. Dimethylselenide, the methylation product of methylselenol, was found to be the major intracellular metabolite. MSA also inhibited HIF-1α expression and VEGF secretion, a possible consequence of HDAC inhibition. The ability of methylselenol to inhibit HDAC activity has not been previously reported, thus providing a novel mechanism of selenium action.

  17. The NAE inhibitor pevonedistat interacts with the HDAC inhibitor belinostat to target AML cells by disrupting the DDR.

    PubMed

    Zhou, Liang; Chen, Shuang; Zhang, Yu; Kmieciak, Maciej; Leng, Yun; Li, Lihong; Lin, Hui; Rizzo, Kathryn A; Dumur, Catherine I; Ferreira-Gonzalez, Andrea; Rahmani, Mohamed; Povirk, Lawrence; Chalasani, Sri; Berger, Allison J; Dai, Yun; Grant, Steven

    2016-05-05

    Two classes of novel agents, NEDD8-activating enzyme (NAE) and histone deacetylase (HDAC) inhibitors, have shown single-agent activity in acute myelogenous leukemia (AML)/myelodysplastic syndrome (MDS). Here we examined mechanisms underlying interactions between the NAE inhibitor pevonedistat (MLN4924) and the approved HDAC inhibitor belinostat in AML/MDS cells. MLN4924/belinostat coadministration synergistically induced AML cell apoptosis with or without p53 deficiency or FLT3-internal tandem duplication (ITD), whereas p53 short hairpin RNA (shRNA) knockdown or enforced FLT3-ITD expression significantly sensitized cells to the regimen. MLN4924 blocked belinostat-induced antiapoptotic gene expression through nuclear factor-κB inactivation. Each agent upregulated Bim, and Bim knockdown significantly attenuated apoptosis. Microarrays revealed distinct DNA damage response (DDR) genetic profiles between individual vs combined MLN4924/belinostat exposure. Whereas belinostat abrogated the MLN4924-activated intra-S checkpoint through Chk1 and Wee1 inhibition/downregulation, cotreatment downregulated multiple homologous recombination and nonhomologous end-joining repair proteins, triggering robust double-stranded breaks, chromatin pulverization, and apoptosis. Consistently, Chk1 or Wee1 shRNA knockdown significantly sensitized AML cells to MLN4924. MLN4924/belinostat displayed activity against primary AML or MDS cells, including those carrying next-generation sequencing-defined poor-prognostic cancer hotspot mutations, and CD34(+)/CD38(-)/CD123(+) populations, but not normal CD34(+) progenitors. Finally, combined treatment markedly reduced tumor burden and significantly prolonged animal survival (P < .0001) in AML xenograft models with negligible toxicity, accompanied by pharmacodynamic effects observed in vitro. Collectively, these findings argue that MLN4924 and belinostat interact synergistically by reciprocally disabling the DDR in AML/MDS cells. This strategy

  18. HDAC3 Inhibitor RGFP966 Modulates Neuronal Memory for Vocal Communication Signals in a Songbird Model.

    PubMed

    Phan, Mimi L; Gergues, Mark M; Mahidadia, Shafali; Jimenez-Castillo, Jorge; Vicario, David S; Bieszczad, Kasia M

    2017-01-01

    Epigenetic mechanisms that modify chromatin conformation have recently been under investigation for their contributions to learning and the formation of memory. For example, the role of enzymes involved in histone acetylation are studied in the formation of long-lasting memories because memory consolidation requires gene expression events that are facilitated by an open state of chromatin. We recently proposed that epigenetic events may control the entry of specific sensory features into long-term memory by enabling transcription-mediated neuronal plasticity in sensory brain areas. Histone deacetylases, like HDAC3, may thereby regulate the specific sensory information that is captured for entry into long-term memory stores (Phan and Bieszczad, 2016). To test this hypothesis, we used an HDAC3-selective inhibitor (RGFP966) to determine whether its application after an experience with a sound stimulus with unique acoustic features could contribute to the formation of a memory that would assist in mediating its later recognition. We gave adult male zebra finches limited exposure to unique conspecific songs (20 repetitions each, well below the normal threshold to form long-term memory), followed by treatment with RGFP966 or vehicle. In different groups, we either made multi-electrode recordings in the higher auditory area NCM (caudal medial nidopallidum), or determined expression of an immediate early gene, zenk (also identified as zif268, egr-1, ngfi-a and krox24), known to participate in neuronal memory in this system. We found that birds treated with RGFP966 showed neuronal memory after only limited exposure, while birds treated with vehicle did not. Strikingly, evidence of neuronal memory in NCM induced by HDAC3-inhibition was lateralized to the left-hemisphere, consistent with our finding that RGFP966-treatment also elevated zenk expression only in the left hemisphere. The present findings show feasibility for epigenetic mechanisms to control neural plasticity

  19. Yakushinamides, Polyoxygenated Fatty Acid Amides That Inhibit HDACs and SIRTs, from the Marine Sponge Theonella swinhoei.

    PubMed

    Takada, Kentaro; Imae, Yasufumi; Ise, Yuji; Ohtsuka, Susumu; Ito, Akihiro; Okada, Shigeru; Yoshida, Minoru; Matsunaga, Shigeki

    2016-09-23

    Yakushinamides A (1) and B (2), prolyl amides of polyoxygenated fatty acids, have been isolated from the marine sponge Theonella swinhoei as inhibitors of HDACs and SIRTs. Their planar structures were determined by interpretation of the NMR data of the intact molecules and tandem FABMS data of the methanolysis products. For the assignment of the relative configurations of the three contiguous oxymethine carbons in 1 and 2, Kishi's universal NMR database was applied to the methanolysis products. During the assignments of relative configurations of the isolated 1-hydroxy-3-methyl moiety in 1 and the isolated 1-hydroxy-2-methyl moiety in 2, we found diagnostic NMR features to distinguish each pair of diastereomers. The absolute configurations of 1 and 2 were determined by a combination of the modified Mosher's method and Marfey's method. Although the modified Mosher's method was successfully applied to the methanolysis product of 1, this method gave an ambiguous result at C-20 when applied to the methanolysis product of 2, even after oxidative cleavage of the C-14 and C-15 bond.

  20. XPLN is modulated by HDAC inhibitors and negatively regulates SPARC expression by targeting mTORC2 in human lung fibroblasts.

    PubMed

    Kamio, Koichiro; Azuma, Arata; Usuki, Jiro; Matsuda, Kuniko; Inomata, Minoru; Nishijima, Nobuhiko; Itakura, Shioto; Hayashi, Hiroki; Kashiwada, Takeru; Kokuho, Nariaki; Atsumi, Kenichiro; Yamaguchi, Tomoyoshi; Fujita, Kazue; Saito, Yoshinobu; Abe, Shinji; Kubota, Kaoru; Gemma, Akihiko

    2017-06-01

    Pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unclear. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that participates in the assembly and turnover of the extracellular matrix, whose expression is regulated by transforming growth factor (TGF)-β1 through activation of mammalian target of rapamycin complex 2 (mTORC2). Exchange factor found in platelets, leukemic, and neuronal tissues (XPLN) is an endogenous inhibitor of mTORC2. However, whether XPLN modulates SPARC expression remains unknown. Herein, we investigated the regulatory mechanisms of XPLN in human lung fibroblasts. Effect of XPLN on mTORC2 activity was evaluated by silencing XPLN in human foetal lung fibroblasts (HFL-1 cells), using small interfering RNA. SPARC expression was quantified by quantitative real-time RT-PCR and western blotting. Fibroblasts were treated with TGF-β1, histone deacetylase (HDAC) inhibitors, entinostat, or vorinostat, to assess their effects on XPLN expression. Moreover, the effect of mTORC1 inhibition on SPARC and XPLN was examined. XPLN depletion stimulated SPARC expression and Akt phosphorylation on Ser473. TGF-β1 treatment down-regulated XPLN via Smad 2/3. XPLN mRNA expression was up-regulated upon treatment with HDAC inhibitors in a concentration-dependent manner, and TGF-β1-induced SPARC expression was reversed by entinostat treatment. mTORC1 inhibition by rapamycin and Raptor depletion stimulated SPARC expression. In conclusion, this is the first study describing the involvement of XPLN in the regulation of SPARC. These findings may help uncover the regulatory mechanisms of the mTORC2-SPARC axis. The up-regulation of XPLN by HDAC inhibitors may be a novel therapeutic approach in patients with IPF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A lazy learning-based QSAR classification study for screening potential histone deacetylase 8 (HDAC8) inhibitors.

    PubMed

    Cao, G P; Arooj, M; Thangapandian, S; Park, C; Arulalapperumal, V; Kim, Y; Kwon, Y J; Kim, H H; Suh, J K; Lee, K W

    2015-01-01

    Histone deacetylases 8 (HDAC8) is an enzyme repressing the transcription of various genes including tumour suppressor gene and has already become a target of human cancer treatment. In an effort to facilitate the discovery of HDAC8 inhibitors, two quantitative structure-activity relationship (QSAR) classification models were developed using K nearest neighbours (KNN) and neighbourhood classifier (NEC). Molecular descriptors were calculated for the data set and database compounds using ADRIANA.Code of Molecular Networks. Principal components analysis (PCA) was used to select the descriptors. The developed models were validated by leave-one-out cross validation (LOO CV). The performances of the developed models were evaluated with an external test set. Highly predictive models were used for database virtual screening. Furthermore, hit compounds were subsequently subject to molecular docking. Five hits were obtained based on consensus scoring function and binding affinity as potential HDAC8 inhibitors. Finally, HDAC8 structures in complex with five hits were also subjected to 5 ns molecular dynamics (MD) simulations to evaluate the complex structure stability. To the best of our knowledge, the NEC classification model used in this study is the first application of NEC to virtual screening for drug discovery.

  2. Overcoming Barriers in Oncolytic Virotherapy with HDAC Inhibitors and Immune Checkpoint Blockade

    PubMed Central

    Marchini, Antonio; Scott, Eleanor M.; Rommelaere, Jean

    2016-01-01

    Oncolytic viruses (OVs) target and destroy cancer cells while sparing their normal counterparts. These viruses have been evaluated in numerous studies at both pre-clinical and clinical levels and the recent Food and Drug Administration (FDA) approval of an oncolytic herpesvirus-based treatment raises optimism that OVs will become a therapeutic option for cancer patients. However, to improve clinical outcome, there is a need to increase OV efficacy. In addition to killing cancer cells directly through lysis, OVs can stimulate the induction of anti-tumour immune responses. The host immune system thus represents a “double-edged sword” for oncolytic virotherapy: on the one hand, a robust anti-viral response will limit OV replication and spread; on the other hand, the immune-mediated component of OV therapy may be its most important anti-cancer mechanism. Although the relative contribution of direct viral oncolysis and indirect, immune-mediated oncosuppression to overall OV efficacy is unclear, it is likely that an initial period of vigorous OV multiplication and lytic activity will most optimally set the stage for subsequent adaptive anti-tumour immunity. In this review, we consider the use of histone deacetylase (HDAC) inhibitors as a means of boosting virus replication and lessening the negative impact of innate immunity on the direct oncolytic effect. We also discuss an alternative approach, aimed at potentiating OV-elicited anti-tumour immunity through the blockade of immune checkpoints. We conclude by proposing a two-phase combinatorial strategy in which initial OV replication and spread is maximised through transient HDAC inhibition, with anti-tumour immune responses subsequently enhanced by immune checkpoint blockade. PMID:26751469

  3. Overcoming Barriers in Oncolytic Virotherapy with HDAC Inhibitors and Immune Checkpoint Blockade.

    PubMed

    Marchini, Antonio; Scott, Eleanor M; Rommelaere, Jean

    2016-01-06

    Oncolytic viruses (OVs) target and destroy cancer cells while sparing their normal counterparts. These viruses have been evaluated in numerous studies at both pre-clinical and clinical levels and the recent Food and Drug Administration (FDA) approval of an oncolytic herpesvirus-based treatment raises optimism that OVs will become a therapeutic option for cancer patients. However, to improve clinical outcome, there is a need to increase OV efficacy. In addition to killing cancer cells directly through lysis, OVs can stimulate the induction of anti-tumour immune responses. The host immune system thus represents a "double-edged sword" for oncolytic virotherapy: on the one hand, a robust anti-viral response will limit OV replication and spread; on the other hand, the immune-mediated component of OV therapy may be its most important anti-cancer mechanism. Although the relative contribution of direct viral oncolysis and indirect, immune-mediated oncosuppression to overall OV efficacy is unclear, it is likely that an initial period of vigorous OV multiplication and lytic activity will most optimally set the stage for subsequent adaptive anti-tumour immunity. In this review, we consider the use of histone deacetylase (HDAC) inhibitors as a means of boosting virus replication and lessening the negative impact of innate immunity on the direct oncolytic effect. We also discuss an alternative approach, aimed at potentiating OV-elicited anti-tumour immunity through the blockade of immune checkpoints. We conclude by proposing a two-phase combinatorial strategy in which initial OV replication and spread is maximised through transient HDAC inhibition, with anti-tumour immune responses subsequently enhanced by immune checkpoint blockade.

  4. Chemoresistance to Valproate Treatment of Bovine Leukemia Virus-Infected Sheep; Identification of Improved HDAC Inhibitors

    PubMed Central

    Gillet, Nicolas; Vandermeers, Fabian; de Brogniez, Alix; Florins, Arnaud; Nigro, Annamaria; François, Carole; Bouzar, Amel-Baya; Verlaeten, Olivier; Stern, Eric; Lambert, Didier M.; Wouters, Johan; Willems, Luc

    2012-01-01

    We previously proved that a histone deacetylase inhibitor (valproate, VPA) decreases the number of leukemic cells in bovine leukemia virus (BLV)-infected sheep. Here, we characterize the mechanisms initiated upon interruption of treatment. We observed that VPA treatment is followed by a decrease of the B cell counts and proviral loads (copies per blood volume). However, all sheep eventually relapsed after different periods of time and became refractory to further VPA treatment. Sheep remained persistently infected with BLV. B lymphocytes isolated throughout treatment and relapse were responsive to VPA-induced apoptosis in cell culture. B cell proliferation is only marginally affected by VPA ex vivo. Interestingly, in four out of five sheep, ex vivo viral expression was nearly undetectable at the time of relapse. In two sheep, a new tumoral clone arose, most likely revealing a selection process exerted by VPA in vivo. We conclude that the interruption of VPA treatment leads to the resurgence of the leukemia in BLV-infected sheep and hypothesize that resistance to further treatment might be due to the failure of viral expression induction. The development of more potent HDAC inhibitors and/or the combination with other compounds can overcome chemoresistance. These observations in the BLV model may be important for therapies against the related Human T-lymphotropic virus type 1. PMID:25436765

  5. Small molecule epigenetic screen identifies novel EZH2 and HDAC inhibitors that target glioblastoma brain tumor-initiating cells

    PubMed Central

    Grinshtein, Natalie; Rioseco, Constanza C.; Marcellus, Richard; Uehling, David; Aman, Ahmed; Lun, Xueqing; Muto, Osamu; Podmore, Lauren; Lever, Jake; Shen, Yaoqing; Blough, Michael D.; Cairncross, Greg J.; Robbins, Stephen M.; Jones, Steven J.; Marra, Marco A.; Al-Awar, Rima; Senger, Donna L.; Kaplan, David R.

    2016-01-01

    Glioblastoma (GBM) is the most lethal and aggressive adult brain tumor, requiring the development of efficacious therapeutics. Towards this goal, we screened five genetically distinct patient-derived brain-tumor initiating cell lines (BTIC) with a unique collection of small molecule epigenetic modulators from the Structural Genomics Consortium (SGC). We identified multiple hits that inhibited the growth of BTICs in vitro, and further evaluated the therapeutic potential of EZH2 and HDAC inhibitors due to the high relevance of these targets for GBM. We found that the novel SAM-competitive EZH2 inhibitor UNC1999 exhibited low micromolar cytotoxicity in vitro on a diverse collection of BTIC lines, synergized with dexamethasone (DEX) and suppressed tumor growth in vivo in combination with DEX. In addition, a unique brain-penetrant class I HDAC inhibitor exhibited cytotoxicity in vitro on a panel of BTIC lines and extended survival in combination with TMZ in an orthotopic BTIC model in vivo. Finally, a combination of EZH2 and HDAC inhibitors demonstrated synergy in vitro by augmenting apoptosis and increasing DNA damage. Our findings identify key epigenetic modulators in GBM that regulate BTIC growth and survival and highlight promising combination therapies. PMID:27449082

  6. Discovery of the first histone deacetylase 6/8 dual inhibitors.

    PubMed

    Olson, David E; Wagner, Florence F; Kaya, Taner; Gale, Jennifer P; Aidoud, Nadia; Davoine, Emeline L; Lazzaro, Fanny; Weïwer, Michel; Zhang, Yan-Ling; Holson, Edward B

    2013-06-13

    We disclose the first small molecule histone deacetylase (HDAC) inhibitor (3, BRD73954) capable of potently and selectively inhibiting both HDAC6 and HDAC8 despite the fact that these isoforms belong to distinct phylogenetic classes within the HDAC family of enzymes. Our data demonstrate that meta substituents of phenyl hydroxamic acids are readily accommodated upon binding to HDAC6 and, furthermore, are necessary for the potent inhibition of HDAC8.

  7. The class I HDAC inhibitor Romidepsin targets inflammatory breast cancer tumor emboli and synergizes with paclitaxel to inhibit metastasis.

    PubMed

    Robertson, Fredika M; Chu, Khoi; Boley, Kimberly M; Ye, Zaiming; Liu, Hui; Wright, Moishia C; Moraes, Ricardo; Zhang, Xuejun; Green, Tessa L; Barsky, Sanford H; Heise, Carla; Cristofanilli, Massimo

    2013-01-01

    Inflammatory breast cancer (IBC) is the most metastatic variant of locally advanced breast cancer. IBC has distinctive characteristics including invasion of tumor emboli into the skin and rapid disease progression. Given our previous studies suggesting that HDAC inhibitors have promise in targeting IBC, the present study revealed that the class I HDAC inhibitor Romidepsin (FK-288, Istodax; Celgene Corporation, Summit, NJ) potently induced destruction of IBC tumor emboli and lymphatic vascular architecture. associated with inhibition of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1alpha, (HIF1alpha) proteins in the Mary-X pre-clinical model of IBC. Romidepsin treatment induced clinically relevant biomarkers in including induction of acetylated Histone 3 (Ac-H3) proteins, apoptosis, and increased p21WAF1/CIP1. Romidepsin, alone and synergistically when combined with Paclitaxel, effectively eliminated both primary tumors and metastatic lesions at multiple sites formed by the SUM149 IBC cell line. This is the first report of the ability of an HDAC inhibitor to eradicate IBC tumor emboli, to destroy the integrity of lymphatic vessel architecture and to target metastasis. Furthermore, Romidepsin, in combination with a taxane, warrants evaluation as a therapeutic strategy that may effectively target the skin involvement and rapid metastasis that are hallmarks of IBC.

  8. HDAC inhibitors enhance the lethality of low dose salinomycin in parental and stem-like GBM cells.

    PubMed

    Booth, Laurence; Roberts, Jane L; Conley, Adam; Cruickshanks, Nichola; Ridder, Thomas; Grant, Steven; Poklepovic, Andrew; Dent, Paul

    2014-03-01

    The present studies determined whether the antibiotic salinomycin interacted with HDAC inhibitors to kill primary human GBM cells. Regardless of PTEN, ERBB1, or p53 mutational status salinomycin interacted with HDAC inhibitors in a synergistic fashion to kill GBM cells. Inhibition of CD95/Caspase 8 or of CD95/RIP-1/AIF signaling suppressed killing by the drug combination. Salinomycin increased the levels of autophagosomes that correlated with increased p62 and LC3II levels; valproate co-treatment correlated with reduced LC3II and p62 expression, and increased caspase 3 cleavage. Molecular inhibition of autophagosome formation was protective against drug exposure. The drug combination enhanced eIF2α phosphorylation and decreased expression of MCL-1 and phosphorylation of mTOR and p70 S6K. Activation of p70 S6K or mTOR promoted cell survival in the face of combined drug exposure. Overexpression of BCL-XL or c-FLIP-s was protective. Collectively our data demonstrate that the lethality of low nanomolar concentrations of salinomycin are enhanced by HDAC inhibitors in GBM cells and that increased death receptor signaling together with reduced mitochondrial function are causal in the combinatorial drug necro-apoptotic killing effect.

  9. The HDAC inhibitor SB939 overcomes resistance to BCR-ABL kinase Inhibitors conferred by the BIM deletion polymorphism in chronic myeloid leukemia.

    PubMed

    Rauzan, Muhammad; Chuah, Charles T H; Ko, Tun Kiat; Ong, S Tiong

    2017-01-01

    Chronic myeloid leukemia (CML) treatment has been improved by tyrosine kinase inhibitors (TKIs) such as imatinib mesylate (IM) but various factors can cause TKI resistance in patients with CML. One factor which contributes to TKI resistance is a germline intronic deletion polymorphism in the BCL2-like 11 (BIM) gene which impairs the expression of pro-apoptotic splice isoforms of BIM. SB939 (pracinostat) is a hydroxamic acid based HDAC inhibitor with favorable pharmacokinetic, physicochemical and pharmaceutical properties, and we investigated if this drug could overcome BIM deletion polymorphism-induced TKI resistance. We found that SB939 corrects BIM pre-mRNA splicing in CML cells with the BIM deletion polymorphism, and induces apoptotic cell death in CML cell lines and primary cells with the BIM deletion polymorphism. More importantly, SB939 both decreases the viability of CML cell lines and primary CML progenitors with the BIM deletion and restores TKI-sensitivity. Our results demonstrate that SB939 overcomes BIM deletion polymorphism-induced TKI resistance, and suggest that SB939 may be useful in treating CML patients with BIM deletion-associated TKI resistance.

  10. The HDAC inhibitor SB939 overcomes resistance to BCR-ABL kinase Inhibitors conferred by the BIM deletion polymorphism in chronic myeloid leukemia

    PubMed Central

    Rauzan, Muhammad; Chuah, Charles T. H.; Ko, Tun Kiat; Ong, S. Tiong

    2017-01-01

    Chronic myeloid leukemia (CML) treatment has been improved by tyrosine kinase inhibitors (TKIs) such as imatinib mesylate (IM) but various factors can cause TKI resistance in patients with CML. One factor which contributes to TKI resistance is a germline intronic deletion polymorphism in the BCL2-like 11 (BIM) gene which impairs the expression of pro-apoptotic splice isoforms of BIM. SB939 (pracinostat) is a hydroxamic acid based HDAC inhibitor with favorable pharmacokinetic, physicochemical and pharmaceutical properties, and we investigated if this drug could overcome BIM deletion polymorphism-induced TKI resistance. We found that SB939 corrects BIM pre-mRNA splicing in CML cells with the BIM deletion polymorphism, and induces apoptotic cell death in CML cell lines and primary cells with the BIM deletion polymorphism. More importantly, SB939 both decreases the viability of CML cell lines and primary CML progenitors with the BIM deletion and restores TKI-sensitivity. Our results demonstrate that SB939 overcomes BIM deletion polymorphism-induced TKI resistance, and suggest that SB939 may be useful in treating CML patients with BIM deletion-associated TKI resistance. PMID:28301600

  11. Time dependent modulation of tumor radiosensitivity by a pan HDAC inhibitor: abexinostat

    PubMed Central

    Rivera, Sofia; Leteur, Céline; Mégnin, Frédérique; Law, Frédéric; Martins, Isabelle; Kloos, Ioana; Depil, Stéphane; Modjtahedi, Nazanine; Perfettini, Jean Luc; Hennequin, Christophe; Deutsch, Eric

    2017-01-01

    Despite prominent role of radiotherapy in lung cancer management, there is an urgent need for strategies increasing therapeutic efficacy. Reversible epigenetic changes are promising targets for combination strategies using HDAC inhibitors (HDACi). Here we evaluated on two NSCLC cell lines, the antitumor effect of abexinostat, a novel pan HDACi combined with irradiation in vitro in normoxia and hypoxia, by clonogenic assays, demonstrating that abexinostat enhances radiosensitivity in a time dependent way with mean SER10 between 1.6 and 2.5 for A549 and H460. We found, by immunofluorescence staining, flow cytometry assays and western blotting, in abexinostat treated cells, increasing radio-induced caspase dependent apoptosis and persistent DNA double-strand breaks associated with decreased DNA damage signalling and repair. Interestingly, we demonstrated on nude mice xenografts that abexinostat potentiates tumor growth delay in combined modality treatments associating not only abexinostat and irradiation but also when adding cisplatin. Altogether, our data demonstrate in vitro and in vivo anti-tumor effect potentiation by abexinostat combined with irradiation in NSCLC. Moreover, our work suggests for the first time to our knowledge promising triple combination opportunities with HDACi, irradiation and cisplatin which deserves further investigations and could be of major interest in the treatment of NSCLC. PMID:28915585

  12. Time dependent modulation of tumor radiosensitivity by a pan HDAC inhibitor: abexinostat.

    PubMed

    Rivera, Sofia; Leteur, Céline; Mégnin, Frédérique; Law, Frédéric; Martins, Isabelle; Kloos, Ioana; Depil, Stéphane; Modjtahedi, Nazanine; Perfettini, Jean Luc; Hennequin, Christophe; Deutsch, Eric

    2017-01-25

    Despite prominent role of radiotherapy in lung cancer management, there is an urgent need for strategies increasing therapeutic efficacy. Reversible epigenetic changes are promising targets for combination strategies using HDAC inhibitors (HDACi).Here we evaluated on two NSCLC cell lines, the antitumor effect of abexinostat, a novel pan HDACi combined with irradiation in vitro in normoxia and hypoxia, by clonogenic assays, demonstrating that abexinostat enhances radiosensitivity in a time dependent way with mean SER10 between 1.6 and 2.5 for A549 and H460. We found, by immunofluorescence staining, flow cytometry assays and western blotting, in abexinostat treated cells, increasing radio-induced caspase dependent apoptosis and persistent DNA double-strand breaks associated with decreased DNA damage signalling and repair. Interestingly, we demonstrated on nude mice xenografts that abexinostat potentiates tumor growth delay in combined modality treatments associating not only abexinostat and irradiation but also when adding cisplatin.Altogether, our data demonstrate in vitro and in vivo anti-tumor effect potentiation by abexinostat combined with irradiation in NSCLC. Moreover, our work suggests for the first time to our knowledge promising triple combination opportunities with HDACi, irradiation and cisplatin which deserves further investigations and could be of major interest in the treatment of NSCLC.

  13. Profile of Class I Histone Deacetylases (HDAC) by Human Dendritic Cells after Alcohol Consumption and In Vitro Alcohol Treatment and Their Implication in Oxidative Stress: Role of HDAC Inhibitors Trichostatin A and Mocetinostat.

    PubMed

    Agudelo, Marisela; Figueroa, Gloria; Parira, Tiyash; Yndart, Adriana; Muñoz, Karla; Atluri, Venkata; Samikkannu, Thangavel; Nair, Madhavan P

    2016-01-01

    Epigenetic mechanisms have been shown to play a role in alcohol use disorders (AUDs) and may prove to be valuable therapeutic targets. However, the involvement of histone deacetylases (HDACs) on alcohol-induced oxidative stress of human primary monocyte-derived dendritic cells (MDDCs) has not been elucidated. In the current study, we took a novel approach combining ex vivo, in vitro and in silico analyses to elucidate the mechanisms of alcohol-induced oxidative stress and role of HDACs in the periphery. ex vivo and in vitro analyses of alcohol-modulation of class I HDACs and activity by MDDCs from self-reported alcohol users and non-alcohol users was performed. Additionally, MDDCs treated with alcohol were assessed using qRT-PCR, western blot, and fluorometric assay. The functional effects of alcohol-induce oxidative stress were measured in vitro using PCR array and in silico using gene expression network analysis. Our findings show, for the first time, that MDDCs from self-reported alcohol users have higher levels of class I HDACs compare to controls and alcohol treatment in vitro differentially modulates HDACs expression. Further, HDAC inhibitors (HDACi) blocked alcohol-induction of class I HDACs and modulated alcohol-induced oxidative stress related genes expressed by MDDCs. In silico analysis revealed new target genes and pathways on the mode of action of alcohol and HDACi. Findings elucidating the ability of alcohol to modulate class I HDACs may be useful for the treatment of alcohol-induced oxidative damage and may delineate new potential immune-modulatory mechanisms.

  14. Effect of clinically approved HDAC inhibitors on Plasmodium, Leishmania and Schistosoma parasite growth.

    PubMed

    Chua, Ming Jang; Arnold, Megan S J; Xu, Weijun; Lancelot, Julien; Lamotte, Suzanne; Späth, Gerald F; Prina, Eric; Pierce, Raymond J; Fairlie, David P; Skinner-Adams, Tina S; Andrews, Katherine T

    2017-04-01

    Malaria, schistosomiasis and leishmaniases are among the most prevalent tropical parasitic diseases and each requires new innovative treatments. Targeting essential parasite pathways, such as those that regulate gene expression and cell cycle progression, is a key strategy for discovering new drug leads. In this study, four clinically approved anti-cancer drugs (Vorinostat, Belinostat, Panobinostat and Romidepsin) that target histone/lysine deacetylase enzymes were examined for in vitro activity against Plasmodium knowlesi, Schistosoma mansoni, Leishmania amazonensis and L. donovani parasites and two for in vivo activity in a mouse malaria model. All four compounds were potent inhibitors of P. knowlesi malaria parasites (IC50 9-370 nM), with belinostat, panobinostat and vorinostat having 8-45 fold selectivity for the parasite over human neonatal foreskin fibroblast (NFF) or human embryonic kidney (HEK 293) cells, while romidepsin was not selective. Each of the HDAC inhibitor drugs caused hyperacetylation of P. knowlesi histone H4. None of the drugs was active against Leishmania amastigote or promastigote parasites (IC50 > 20 μM) or S. mansoni schistosomula (IC50 > 10 μM), however romidepsin inhibited S. mansoni adult worm parings and egg production (IC50 ∼10 μM). Modest in vivo activity was observed in P. berghei infected mice dosed orally with vorinostat or panobinostat (25 mg/kg twice daily for four days), with a significant reduction in parasitemia observed on days 4-7 and 4-10 after infection (P < 0.05), respectively.

  15. Effects of the Histone Deacetylase Inhibitor Valproic Acid on Human Pericytes In Vitro

    PubMed Central

    Friman, Tomas; Dencker, Lennart; Sundberg, Christian; Scholz, Birger

    2011-01-01

    Microvascular pericytes are of key importance in neoformation of blood vessels, in stabilization of newly formed vessels as well as maintenance of angiostasis in resting tissues. Furthermore, pericytes are capable of differentiating into pro-fibrotic collagen type I producing fibroblasts. The present study investigates the effects of the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on pericyte proliferation, cell viability, migration and differentiation. The results show that HDAC inhibition through exposure of pericytes to VPA in vitro causes the inhibition of pericyte proliferation and migration with no effect on cell viability. Pericyte exposure to the potent HDAC inhibitor Trichostatin A caused similar effects on pericyte proliferation, migration and cell viability. HDAC inhibition also inhibited pericyte differentiation into collagen type I producing fibroblasts. Given the importance of pericytes in blood vessel biology a qPCR array focusing on the expression of mRNAs coding for proteins that regulate angiogenesis was performed. The results showed that HDAC inhibition promoted transcription of genes involved in vessel stabilization/maturation in human microvascular pericytes. The present in vitro study demonstrates that VPA influences several aspects of microvascular pericyte biology and suggests an alternative mechanism by which HDAC inhibition affects blood vessels. The results raise the possibility that HDAC inhibition inhibits angiogenesis partly through promoting a pericyte phenotype associated with stabilization/maturation of blood vessels. PMID:21966390

  16. Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents

    PubMed Central

    Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

    2013-01-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while

  17. Resveratrol as a pan-HDAC inhibitor alters the acetylation status of histone [corrected] proteins in human-derived hepatoblastoma cells.

    PubMed

    Venturelli, Sascha; Berger, Alexander; Böcker, Alexander; Busch, Christian; Weiland, Timo; Noor, Seema; Leischner, Christian; Schleicher, Sabine; Mayer, Mascha; Weiss, Thomas S; Bischoff, Stephan C; Lauer, Ulrich M; Bitzer, Michael

    2013-01-01

    The polyphenolic alcohol resveratrol has demonstrated promising activities for the prevention and treatment of cancer. Different modes of action have been described for resveratrol including the activation of sirtuins, which represent the class III histone deacetylases (HDACs). However, little is known about the activity of resveratrol on the classical HDACs of class I, II and IV, although these classes are involved in cancer development or progression and inhibitors of HDACs (HDACi) are currently under investigation as promising novel anticancer drugs. We could show by in silico docking studies that resveratrol has the chemical structure to inhibit the activity of different human HDAC enzymes. In vitro analyses of overall HDAC inhibition and a detailed HDAC profiling showed that resveratrol inhibited all eleven human HDACs of class I, II and IV in a dose-dependent manner. Transferring this molecular mechanism into cancer therapy strategies, resveratrol treatment was analyzed on solid tumor cell lines. Despite the fact that hepatocellular carcinoma (HCC) is known to be particularly resistant against conventional chemotherapeutics, treatment of HCC with established HDACi already has shown promising results. Testing of resveratrol on hepatoma cell lines HepG2, Hep3B and HuH7 revealed a dose-dependent antiproliferative effect on all cell lines. Interestingly, only for HepG2 cells a specific inhibition of HDACs and in turn a histone hyperacetylation caused by resveratrol was detected. Additional testing of human blood samples demonstrated a HDACi activity by resveratrol ex vivo. Concluding toxicity studies showed that primary human hepatocytes tolerated resveratrol, whereas in vivo chicken embryotoxicity assays demonstrated severe toxicity at high concentrations. Taken together, this novel pan-HDACi activity opens up a new perspective of resveratrol for cancer therapy alone or in combination with other chemotherapeutics. Moreover, resveratrol may serve as a lead

  18. HDAC1 and HDAC2 Restrain the Intestinal Inflammatory Response by Regulating Intestinal Epithelial Cell Differentiation

    PubMed Central

    Turgeon, Naomie; Blais, Mylène; Gagné, Julie-Moore; Tardif, Véronique; Boudreau, François; Perreault, Nathalie; Asselin, Claude

    2013-01-01

    Acetylation and deacetylation of histones and other proteins depends on histone acetyltransferases and histone deacetylases (HDACs) activities, leading to either positive or negative gene expression. HDAC inhibitors have uncovered a role for HDACs in proliferation, apoptosis and inflammation. However, little is known of the roles of specific HDACs in intestinal epithelial cells (IEC). We investigated the consequences of ablating both HDAC1 and HDAC2 in murine IECs. Floxed Hdac1 and Hdac2 homozygous mice were crossed with villin-Cre mice. Mice deficient in both IEC HDAC1 and HDAC2 weighed less and survived more than a year. Colon and small intestinal sections were stained with hematoxylin and eosin, or with Alcian blue and Periodic Acid Schiff for goblet cell identification. Tissue sections from mice injected with BrdU for 2 h, 14 h and 48 h were stained with anti-BrdU. To determine intestinal permeability, 4-kDa FITC-labeled dextran was given by gavage for 3 h. Microarray analysis was performed on total colon RNAs. Inflammatory and IEC-specific gene expression was assessed by Western blot or semi-quantitative RT-PCR and qPCR with respectively total colon protein and total colon RNAs. HDAC1 and HDAC2-deficient mice displayed: 1) increased migration and proliferation, with elevated cyclin D1 expression and phosphorylated S6 ribosomal protein, a downstream mTOR target; 2) tissue architecture defects with cell differentiation alterations, correlating with reduction of secretory Paneth and goblet cells in jejunum and goblet cells in colon, increased expression of enterocytic markers such as sucrase-isomaltase in the colon, increased expression of cleaved Notch1 and augmented intestinal permeability; 3) loss of tissue homeostasis, as evidenced by modifications of claudin 3 expression, caspase-3 cleavage and Stat3 phosphorylation; 4) chronic inflammation, as determined by inflammatory molecular expression signatures and altered inflammatory gene expression. Thus

  19. Docking Studies of Glutamine Valproic Acid Derivative (S)-5- amino-2-(heptan-4-ylamino)-5-oxopentanoic Acid (Gln-VPA) on HDAC8 with Biological Evaluation in HeLa Cells.

    PubMed

    Martínez-Ramos, F; Luna-Palencia, G R; Vásquez-Moctezuma, I; Méndez-Luna, D; Fragoso-Vázquez, M J; Trujillo-Ferrara, J; Meraz-Ríos, M A; Mendieta-Wejebe, J E; Correa-Basurto, J

    2016-01-01

    In this contribution, we focused on evaluating a novel compound developed by our group. This molecule, derived from glutamine (Gln) and valproic acid (VPA), denominated (S)- 5-amino-2-(heptan-4-ylamino)-5-oxopentanoic acid (Gln-VPA), was submitted to docking studies on histone deacetylase 8 (HDAC8) to explore its non-bonded interactions. The theoretical results were validated in HeLa cells as a cancer cell model and in human dermal fibroblasts as a normal cell model. The effects of Gln-VPA on HeLa and normal fibroblasts in terms of cell survival and the ability to inhibit HDAC activity in nude nuclear proteins and in nuclear proteins of whole cells treated for 24 h were analyzed. The HeLa cell cycle was analyzed after 24 and 48 h of treatment with Gln-VPA. The docking studies show that Gln-VPA can reach the catalytic site of HDAC8. Gln-VPA was organically synthesized with a purity greater than 97%, and its structure was validated using mass spectrometry, nuclear magnetic resonance and infrared spectroscopy. Gln-VPA showed a similar effect to VPA as an HDAC inhibitor but with less toxicity to fibroblasts. Although Gln-VPA was less efficient than VPA in reducing the survival of HeLa cells, it could be studied for use as a cancer cell sensitizer.

  20. Intensified antineoplastic effect by combining an HDAC-inhibitor, an mTOR-inhibitor and low dosed interferon alpha in prostate cancer cells

    PubMed Central

    Tsaur, Igor; Hudak, Lukasz; Makarević, Jasmina; Juengel, Eva; Mani, Jens; Borgmann, Hendrik; Gust, Kilian M; Schilling, David; Bartsch, Georg; Nelson, Karen; Haferkamp, Axel; Blaheta, Roman A

    2015-01-01

    A significant proportion of men diagnosed with prostate cancer (PCa) eventually develop metastatic disease, which progresses to castration resistance, despite initial response to androgen deprivation. As anticancer therapy has become increasingly effective, acquired drug resistance has emerged, limiting efficacy. Combination treatment, utilizing different drug classes, exemplifies a possible strategy to foil resistance development. The effects of the triple application of the histone deacetylase (HDAC) inhibitor valproic acid (VPA), the mammalian target of rapamycin inhibitor everolimus and low dosed interferon alpha (IFNα) on PCa cell growth and dissemination capacity were investigated. For that purpose, the human PCa cell lines, PC-3, DU-145 and LNCaP were treated with the combined regimen or separate single agents. Cell growth was investigated by the MTT dye reduction assay. Flow cytometry served to analyse cell cycle progression. Adhesion to vascular endothelium or immobilized collagen, fibronectin and laminin was quantified. Migration and invasion characteristics were determined by the modified Boyden chamber assay. Integrin α and β subtypes were investigated by flow cytometry, western blotting and RT-PCR. Integrin related signalling, Epidermal Growth Factor Receptor (EGFr), Akt, p70S6kinase and extracellular signal-regulated kinases (ERK)1/2 activation were also assessed. The triple application of VPA, everolimus and low dosed IFNα blocked tumour cell growth and dissemination significantly better than any agent alone. Antitumour effects were associated with pronounced alteration in the cell cycle machinery, intracellular signalling and integrin expression profile. Combining VPA, everolimus and low dosed IFNα might be a promising option to counteract resistance development and improve outcome in PCa patients. PMID:25808196

  1. ZEB1-associated drug resistance in cancer cells is reversed by the class I HDAC inhibitor mocetinostat

    PubMed Central

    Meidhof, Simone; Brabletz, Simone; Lehmann, Waltraut; Preca, Bogdan-Tiberius; Mock, Kerstin; Ruh, Manuel; Schüler, Julia; Berthold, Maria; Weber, Anika; Burk, Ulrike; Lübbert, Michael; Puhr, Martin; Culig, Zoran; Wellner, Ulrich; Keck, Tobias; Bronsert, Peter; Küsters, Simon; Hopt, Ulrich T; Stemmler, Marc P; Brabletz, Thomas

    2015-01-01

    Therapy resistance is a major clinical problem in cancer medicine and crucial for disease relapse and progression. Therefore, the clinical need to overcome it, particularly for aggressive tumors such as pancreatic cancer, is very high. Aberrant activation of an epithelial–mesenchymal transition (EMT) and an associated cancer stem cell phenotype are considered a major cause of therapy resistance. Particularly, the EMT-activator ZEB1 was shown to confer stemness and resistance. We applied a systematic, stepwise strategy to interfere with ZEB1 function, aiming to overcome drug resistance. This led to the identification of both its target gene miR-203 as a major drug sensitizer and subsequently the class I HDAC inhibitor mocetinostat as epigenetic drug to interfere with ZEB1 function, restore miR-203 expression, repress stemness properties, and induce sensitivity against chemotherapy. Thereby, mocetinostat turned out to be more effective than other HDAC inhibitors, such as SAHA, indicating the relevance of the screening strategy. Our data encourage the application of mechanism-based combinations of selected epigenetic drugs with standard chemotherapy for the rational treatment of aggressive solid tumors, such as pancreatic cancer. PMID:25872941

  2. Acetylation of core histones in response to HDAC inhibitors is diminished in mitotic HeLa cells

    PubMed Central

    Patzlaff, Jason S.; Terrenoire, Edith; Turner, Bryan M.; Earnshaw, William C.; Paulson, James R.

    2010-01-01

    Histone acetylation is a key modification that regulates chromatin accessibility. Here we show that treatment with butyrate or other histone deacetylase (HDAC) inhibitors does not induce histone hyperacetylation in metaphase-arrested HeLa cells. When compared to similarly treated interphase cells, acetylation levels are significantly decreased in all four core histones and at all individual sites examined. However, the extent of the decrease varies, ranging from only slight reduction at H3K23 and H4K12 to no acetylation at H3K27 and barely detectable acetylation at H4K16. Our results show that the bulk effect is not due to increased or butyrate-insensitive HDAC activity, though these factors may play a role with some individual sites. We conclude that the lack of histone acetylation during mitosis is primarily due to changes in histone acetyltransferases (HATs) or changes in chromatin. The effects of protein phosphatase inhibitors on histone acetylation in cell lysates suggest that the reduced ability of histones to become acetylated in mitotic cells depends on protein phosphorylation. PMID:20452346

  3. ST7612AA1, a thioacetate-ω(γ-lactam carboxamide) derivative selected from a novel generation of oral HDAC inhibitors.

    PubMed

    Giannini, Giuseppe; Vesci, Loredana; Battistuzzi, Gianfranco; Vignola, Davide; Milazzo, Ferdinando M; Guglielmi, Mario Berardino; Barbarino, Marcella; Santaniello, Mosè; Fantò, Nicola; Mor, Marco; Rivara, Silvia; Pala, Daniele; Taddei, Maurizio; Pisano, Claudio; Cabri, Walter

    2014-10-23

    A systematic study of medicinal chemistry aimed at identifying a new generation of HDAC inhibitors, through the introduction of a thiol zinc-binding group (ZBG) and of an amide-lactam in the ω-position of the polyethylene chain of the vorinostat scaffold, allowed the selection of a new class of potent pan-HDAC inhibitors (pan-HDACis). Simple, highly versatile, and efficient synthetic approaches were used to synthesize a library of these new derivatives, which were then submitted to a screening for HDAC inhibition as well as to a preliminary in vitro assessment of their antiproliferative activity. Molecular docking into HDAC crystal structures suggested a binding mode for these thiol derivatives consistent with the stereoselectivity observed upon insertion of amide-lactam substituents in the ω-position. ST7612AA1 (117), selected as a drug candidate for further development, showed an in vitro activity in the nanomolar range associated with a remarkable in vivo antitumor activity, highly competitive with the most potent HDAC inhibitors, currently under clinical trials. A preliminary study of PK and metabolism is also illustrated.

  4. TACC3 overexpression in cholangiocarcinoma correlates with poor prognosis and is a potential anti-cancer molecular drug target for HDAC inhibitors

    PubMed Central

    Wang, Jian-ming; Schemmer, Peter; Yang, Yan; Liu, Yan; Qian, Ya-wei; Qi, Wei-peng; Zhang, Jian; Shen, Qi; Yang, Tao

    2016-01-01

    Histone deacetylases (HDACs) have been implicated in multiple malignant tumors, and HDAC inhibitors (HDACIs) exert anti-cancer effects. However, the expression of HDACs and the anti-tumor mechanism of HDACIs in cholangiocarcinoma (CCA) have not yet been elucidated. In this study, we found that expression of HDACs 2, 3, and 8 were up-regulated in CCA tissues and those patients with high expression of HDAC2 and/or HDAC3 had a worse prognosis. In CCA cells, two HDACIs, trichostatin (TSA) and vorinostat (SAHA), suppressed proliferation and induced apoptosis and G2/M cycle arrest. Microarray analysis revealed that TACC3 mRNA was down-regulated in CCA cells treated with TSA. TACC3 was highly expressed in CCA tissues and predicted a poor prognosis in CCA patients. TACC3 knockdown induced G2/M cycle arrest and suppressed the invasion, metastasis, and proliferation of CCA cells, both in vitro and in vivo. TACC3 overexpression reversed the effects of its knockdown. These findings suggest TACC3 may be a useful prognostic biomarker for CCA and is a potential therapeutic target for HDACIs. PMID:27705912

  5. HDAC inhibitors, MS-275 and salermide, potentiates the anticancer effect of EF24 in human pancreatic cancer cells

    PubMed Central

    Yar Saglam, Atiye Seda; Yilmaz, Akin; Onen, Hacer Ilke; Alp, Ebru; Kayhan, Handan; Ekmekci, Abdullah

    2016-01-01

    Histone deacetylases (HDACs) play a major role in the regulation of chromatin structure and gene expression by changing acetylation status of histone and non-histone proteins. MS-275 (entinostat, MS) is a well-known benzamide-based HDACI and Salermide (SAL), a reverse amide compound HDACI, have antiproliferative effects on several human cancer cells. In this study, we aimed to investigate the effects of HDACIs (MS and SAL) alone and/or combined use with EF24 (EF), a novel synthetic curcumin analog, on human pancreatic cancer cell line (BxPC-3). In vitro, BxPC-3 cells were exposed to varying concentrations of MS, SAL with or without EF, and their effects on cell viability, acetylated Histone H3 and H4 levels, cytotoxicity, and cleaved caspase 3 levels, and cell cycle distribution were measured. The viability of BxPC-3 cells decreased significantly after treatment with EF, MS and SAL treatments. MS and SAL treatment increased the acetylation of histone H3 and H4 in a dose dependent manner. MS and SAL alone or combined with EF were increased the number of cells in G1 phase. In addition, treatment with agents significantly decreased the ratio of cell in G2/M phase. There were significant dose-dependent increases at cleaved Caspase 3 levels after MS treatment but not after SAL treatment. Our results showed that HDAC inhibitors (MS and SAL), when combined with EF, may effectively reduce pancreatic cancer cell (BxPC-3) progression and stop the cell cycle at G1 phase. Further molecular analyses are needed to understand the fundamental molecular consequences of HDAC inhibition in pancreas cancer cells. PMID:27330528

  6. Rosiglitazone synergizes the neuroprotective effects of valproic acid against quinolinic acid-induced neurotoxicity in rats: targeting PPARγ and HDAC pathways.

    PubMed

    Mishra, Jitendriya; Chaudhary, Tanya; Kumar, Anil

    2014-08-01

    Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder which affects medium spiny GABAergic neurons mainly in the striatum. Oxidative damage, neuro-inflammation, apoptosis, protein aggregation, and signaling of neurotrophic factors are some of the common cellular pathways involved in HD. Quinolinic acid (QA) causes excitotoxicity by stimulating N-methyl-D-aspartate receptors via calcium overload leading to neurodegeneration. Neuroprotective potential of peroxisome proliferator activated receptor-γ (PPARγ) agonists and histone deacetylase (HDAC) inhibitors have been well documented in experimental models of neurodegenerative disorders; however, their exact mechanisms are not clear. Therefore, present study has been designed to explore possible neuroprotective mechanism of valproic acid (VPA) and its interaction with rosiglitazone against QA induced HD-like symptoms in rats. Single bilateral intrastriatal QA (200 nmol/2 μl saline) administration significantly caused motor incoordination, memory impairment, oxidative damage, mitochondrial dysfunction (complex I, II, II and IV), cellular alterations [tumor necrosis factor-alpha (TNF-α), caspase-3, brain derived neurotrophic factor, acetylcholinesterase], and striatal neurodegeneration as compared to sham group. Treatment with rosiglitazone (5, 10 mg/kg) and VPA (100, 200 mg/kg) for 21 days significantly attenuated these behavioral, biochemical, and cellular alterations as compared to control (QA 200 nmol) group. However, VPA (100 mg/kg) treatment in combination with rosiglitazone (5 mg/kg) for 21 days synergized their neuroprotective effect, which was significant as compared to their effects per se in QA-treated animals. The present study provides an evidence of possible interplay of PPARγ agonists and HDAC inhibitors as a novel therapeutic strategy in the management of HD.

  7. Phase I study of the mTOR inhibitor ridaforolimus and the HDAC inhibitor vorinostat in advanced renal cell carcinoma and other solid tumors

    PubMed Central

    Zibelman, Matthew; Wong, Yu-Ning; Devarajan, Karthik; Malizzia, Lois; Corrigan, Alycia; Olszanski, Anthony J.; Denlinger, Crystal S.; Roethke, Susan K.; Tetzlaff, Colleen H.; Plimack, Elizabeth R.

    2015-01-01

    Background Drugs inhibiting the mammalian target of rapamycin (mTOR) are approved in the treatment of renal cell carcinoma (RCC), but resistance inevitably emerges. Proposed escape pathways include increased phosphorylation of Akt, which can be down regulated by histone deacetylase (HDAC) inhibitors. We hypothesized that co-treatment with the mTOR inhibitor ridaforolimus and the HDAC inhibitor vorinostat may abrogate resistance in RCC. Methods This phase 1 study evaluated the co-administration of ridaforolimus and vorinostat in patients with advanced solid tumors. The primary objective was to determine the maximum tolerated dose (MTD) in RCC patients. Although all solid tumors were allowed, prior cytotoxic chemotherapy was limited to 1 regimen. Using a modified 3+3 dose escalation design, various dose combinations were tested concurrently in separate cohorts. Efficacy was a secondary endpoint. Results Fifteen patients were treated at one of three dose levels, thirteen with RCC (10 clear cell, 3 papillary). Dosing was limited by thrombocytopenia. The MTD was determined to be ridaforolimus 20mg daily days 1–5 with vorinostat 100mg BID days 1–3 weekly, however late onset thrombocytopenia led to a lower recommended phase II dose: ridaforolimus 20mg daily days 1–5 with vorinostat 100mg daily days 1–3 weekly. Two patients, both with papillary RCC, maintained disease control for 54 and 80 weeks, respectively. Conclusions The combination of ridaforolimus and vorinostat was tolerable at the recommended phase II dose. Two patients with papillary RCC experienced prolonged disease stabilization, thus further study of combined HDAC and mTOR inhibition in this population is warranted. PMID:26091915

  8. Phase I dose-escalation study of the mTOR inhibitor sirolimus and the HDAC inhibitor vorinostat in patients with advanced malignancy

    PubMed Central

    Park, Haeseong; Garrido-Laguna, Ignacio; Naing, Aung; Fu, Siqing; Falchook, Gerald S.; Piha-Paul, Sarina A.; Wheler, Jennifer J.; Hong, David S.; Tsimberidou, Apostolia M.; Subbiah, Vivek; Zinner, Ralph G.; Kaseb, Ahmed O.; Patel, Shreyaskumar; Fanale, Michelle A.; Velez-Bravo, Vivianne M.; Meric-Bernstam, Funda; Kurzrock, Razelle; Janku, Filip

    2016-01-01

    Preclinical models suggest that histone deacetylase (HDAC) and mammalian target of rapamycin (mTOR) inhibitors have synergistic anticancer activity. We designed a phase I study to determine the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), and dose-limiting toxicities (DLTs) of combined mTOR inhibitor sirolimus (1 mg-5 mg PO daily) and HDAC inhibitor vorinostat (100 mg-400 mg PO daily) in patients with advanced cancer. Seventy patients were enrolled and 46 (66%) were evaluable for DLT assessment since they completed cycle 1 without dose modification unless they had DLT. DLTs comprised grade 4 thrombocytopenia (n = 6) and grade 3 mucositis (n = 1). Sirolimus 4 mg and vorinostat 300 mg was declared RP2D because MTD with sirolimus 5 mg caused significant thrombocytopenia. The grade 3 and 4 drug-related toxic effects (including DLTs) were thrombocytopenia (31%), neutropenia (8%), anemia (7%), fatigue (3%), mucositis (1%), diarrhea (1%), and hyperglycemia (1%). Of the 70 patients, 35 (50%) required dose interruption or modification and 61 were evaluable for response. Partial responses were observed in refractory Hodgkin lymphoma (−78%) and perivascular epithelioid tumor (−54%), and stable disease in hepatocellular carcinoma and fibromyxoid sarcoma. In conclusion, the combination of sirolimus and vorinostat was feasible, with thrombocytopenia as the main DLT. Preliminary anticancer activity was observed in patients with refractory Hodgkin lymphoma, perivascular epithelioid tumor, and hepatocellular carcinoma. PMID:27589687

  9. A MEK/PI3K/HDAC inhibitor combination therapy for KRAS mutant pancreatic cancer cells

    PubMed Central

    Ischenko, Irene; Petrenko, Oleksi; Hayman, Michael J.

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive, metastatic disease with limited treatment options. Factors contributing to the metastatic predisposition and therapy resistance in pancreatic cancer are not well understood. Here, we used a mouse model of KRAS-driven pancreatic carcinogenesis to define distinct subtypes of PDAC metastasis: epithelial, mesenchymal and quasi-mesenchymal. We examined pro-survival signals in these cells and the therapeutic response differences between them. Our data indicate that the initiation and maintenance of the transformed state are separable, and that KRAS dependency is not a fundamental constant of KRAS-initiated tumors. Moreover, some cancer cells can shuttle between the KRAS dependent (drug-sensitive) and independent (drug-tolerant) states and thus escape extinction. We further demonstrate that inhibition of KRAS signaling alone via co-targeting the MAPK and PI3K pathways fails to induce extensive tumor cell death and, therefore, has limited efficacy against PDAC. However, the addition of histone deacetylase (HDAC) inhibitors greatly improves outcomes, reduces the self-renewal of cancer cells, and blocks cancer metastasis in vivo. Our results suggest that targeting HDACs in combination with KRAS or its effector pathways provides an effective strategy for the treatment of PDAC. PMID:26158412

  10. Disulfide cross-linked micelles of novel HDAC inhibitor thailandepsin A for the treatment of breast cancer

    PubMed Central

    Xiao, Kai; Li, Yuan-Pei; Wang, Cheng; Ahmad, Sarah; Vu, Michael; Kuma, Krishneel; Cheng, Yi-Qiang; Lam, Kit S.

    2015-01-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of targeted therapy against cancers. Thailandepsin A (TDP-A) is a recently discovered class I HDAC inhibitor with broad anti-proliferative activities. In the present study, we aimed to investigate the potential of TDP-A in the treatment of breast cancer. We demonstrated that TDP-A inhibited cell proliferation and induced apoptosis in breast cancer cells at low nanomolar concentrations. TDP-A activated the intrinsic apoptotic pathway through increase of pro-apoptotic protein Bax, decrease of anti-apoptotic Bcl-2, and cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP). TDP-A also induced cell cycle arrest at the G2/M phase, and promoted the production of reactive oxygen species (ROS). We have successfully encapsulated TDP-A into our recently developed disulfide cross-linked micelles (DCMs), improving its water solubility and targeted delivery. TDP-A loaded DCMs (TDP-A/DCMs) possess the characteristics of high loading capacity (> 20%, w/w), optimal and monodisperse particle size (16 ± 4 nm), outstanding stability with redox stimuli-responsive disintegration, sustained drug release, and preferential uptake in breast tumors. In the MDA-MB-231 breast cancer xenograft model, TDP-A/DCMs were more efficacious than the FDA-approved FK228 at well-tolerated doses. Furthermore, TDP-A/DCMs exhibited synergistic anticancer effects when combined with the proteasome inhibitor bortezomib (BTZ) loaded DCMs (BTZ/DCMs). Our results indicate that TDP-A nanoformulation alone or in combination with BTZ nanoformulation are efficacious against breast cancer. PMID:26218744

  11. Enhanced anti-tumor activity induced by adoptive T cell transfer and the adjunctive use of the HDAC Inhibitor LAQ824

    PubMed Central

    Vo, Dan D.; Prins, Robert M.; Begley, Jonathan L.; Donahue, Timothy R.; Morris, Lilah F.; Bruhn, Kevin W.; de la Rocha, Pilar; Yang, Meng-Yin; Mok, Stephen; Garban, Hermes J.; Craft, Noah; Economou, James S.; Marincola, Francesco M.; Wang, Ena; Ribas, Antoni

    2009-01-01

    Tumors grow in the presence of antigen-specific T cells, suggesting the existence of intrinsic cancer cell escape mechanisms. We hypothesized that a histone deacetylase (HDAC) inhibitor could sensitize tumor cells to immunotherapy because this class of agents has been reported to increase tumor antigen expression and shift gene expression to a pro-apoptotic milieu in cancer cells. To test this question, we treated B16 murine melanoma with the combination of the HDAC inhibitor LAQ824 together with the adoptive transfer (AT) of gp100 melanoma antigen-specific pmel-1 T cells. The combined therapy significantly improved antitumor activity through several mechanisms: 1) increase in MHC and tumor-associated antigen (TAA) expression by tumor cells; 2) decrease in competing endogenous lymphocytes in recipient mice, resulting in a proliferative advantage for the adoptively transferred cells; and 3) improvement in the functional activity of the adoptively transferred lymphocytes. We confirmed the beneficial effects of this HDAC inhibitor as sensitizer to immunotherapy in a different model of prophylactic prime-boost vaccination with the melanoma antigen tyrosinase-related protein-2 (TRP2), which also demonstrated a significant improvement in antitumor activity against B16 melanoma. In conclusion, the HDAC inhibitor LAQ824 significantly enhances tumor immunotherapy through effects on target tumor cells as well as improving the antitumor activity of tumor antigen-specific lymphocytes. PMID:19861533

  12. Activation of mPTP-dependent mitochondrial apoptosis pathway by a novel pan HDAC inhibitor resminostat in hepatocellular carcinoma cells

    SciTech Connect

    Fu, Meili; Shi, Wenhong; Li, Zhengling; Liu, Haiyan

    2016-09-02

    Over-expression and aberrant activation of histone deacetylases (HDACs) are often associated with poor prognosis of hepatocellular carcinoma (HCC). Here, we evaluated the potential anti-hepatocellular carcinoma (HCC) cell activity by resminostat, a novel pan HDAC inhibitor (HDACi). We demonstrated that resminostat induced potent cytotoxic and anti-proliferative activity against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, resminostat treatment in HCC cells activated mitochondrial permeability transition pore (mPTP)-dependent apoptosis pathway, which was evidenced by physical association of cyclophilin-D and adenine nucleotide translocator 1 (ANT-1), mitochondrial depolarization, cytochrome C release and caspase-9 activation. Intriguingly, the mPTP blockers (sanglifehrin A and cyclosporine A), shRNA knockdown of cyclophilin-D or the caspase-9 inhibitor dramatically attenuated resminostat-induced HCC cell apoptosis and cytotoxicity. Reversely, HCC cells with exogenous cyclophilin-D over-expression were hyper-sensitive to resminostat. Intriguingly, a low concentration of resminostat remarkably potentiated sorafenib-induced mitochondrial apoptosis pathway activation, leading to a profound cytotoxicity in HCC cells. The results of this preclinical study indicate that resminostat (or plus sorafenib) could be further investigated as a valuable anti-HCC strategy. - Highlights: • Resminostat inhibits human HCC cell survival and proliferation. • Resminostat activates mPTP-dependent mitochondrial apoptosis pathway in HCC cells. • Resminostat potentiates sorafenib-induced mitochondrial apoptosis pathway activation. • mPTP or caspase-9 inhibition attenuates apoptosis by resminostat or plus sorafenib.

  13. Design and synthesis of a potent histone deacetylase inhibitor.

    PubMed

    Liu, Tao; Kapustin, Galina; Etzkorn, Felicia A

    2007-05-03

    Histone deacetylase (HDAC) inhibitors have potential for cancer therapy. An HDAC inhibitor based on a cyclic peptide mimic of known structure, linked by an aliphatic chain to a hydroxamic acid, was designed and synthesized. The chimeric compound showed potent competitive inhibition of nuclear HDACs, with an IC50 value of 46 nM and a Ki value of 13.7 nM. The designed inhibitor showed 4-fold selectivity for HDAC1 (57 nM) over HDAC8 (231 nM).

  14. HDAC6 as a target for neurodegenerative diseases: what makes it different from the other HDACs?

    PubMed Central

    2013-01-01

    Histone deacetylase (HDAC) inhibitors have been demonstrated to be beneficial in animal models of neurodegenerative diseases. Such results were mainly associated with the epigenetic modulation caused by HDACs, especially those from class I, via chromatin deacetylation. However, other mechanisms may contribute to the neuroprotective effect of HDAC inhibitors, since each HDAC may present distinct specific functions within the neurodegenerative cascades. Such an example is HDAC6 for which the role in neurodegeneration has been partially elucidated so far. The strategy to be adopted in promising therapeutics targeting HDAC6 is still controversial. Specific inhibitors exert neuroprotection by increasing the acetylation levels of α-tubulin with subsequent improvement of the axonal transport, which is usually impaired in neurodegenerative disorders. On the other hand, an induction of HDAC6 would theoretically contribute to the degradation of protein aggregates which characterize various neurodegenerative disorders, including Alzheimer’s, Parkinson’s and Hutington’s diseases. This review describes the specific role of HDAC6 compared to the other HDACs in the context of neurodegeneration, by collecting in silico, in vitro and in vivo results regarding the inhibition and/or knockdown of HDAC6 and other HDACs. Moreover, structure, function, subcellular localization, as well as the level of HDAC6 expression within brain regions are reviewed and compared to the other HDAC isoforms. In various neurodegenerative diseases, the mechanisms underlying HDAC6 interaction with other proteins seem to be a promising approach in understanding the modulation of HDAC6 activity. PMID:23356410

  15. HDAC6 as a target for neurodegenerative diseases: what makes it different from the other HDACs?

    PubMed

    Simões-Pires, Claudia; Zwick, Vincent; Nurisso, Alessandra; Schenker, Esther; Carrupt, Pierre-Alain; Cuendet, Muriel

    2013-01-29

    Histone deacetylase (HDAC) inhibitors have been demonstrated to be beneficial in animal models of neurodegenerative diseases. Such results were mainly associated with the epigenetic modulation caused by HDACs, especially those from class I, via chromatin deacetylation. However, other mechanisms may contribute to the neuroprotective effect of HDAC inhibitors, since each HDAC may present distinct specific functions within the neurodegenerative cascades. Such an example is HDAC6 for which the role in neurodegeneration has been partially elucidated so far. The strategy to be adopted in promising therapeutics targeting HDAC6 is still controversial. Specific inhibitors exert neuroprotection by increasing the acetylation levels of α-tubulin with subsequent improvement of the axonal transport, which is usually impaired in neurodegenerative disorders. On the other hand, an induction of HDAC6 would theoretically contribute to the degradation of protein aggregates which characterize various neurodegenerative disorders, including Alzheimer's, Parkinson's and Hutington's diseases. This review describes the specific role of HDAC6 compared to the other HDACs in the context of neurodegeneration, by collecting in silico, in vitro and in vivo results regarding the inhibition and/or knockdown of HDAC6 and other HDACs. Moreover, structure, function, subcellular localization, as well as the level of HDAC6 expression within brain regions are reviewed and compared to the other HDAC isoforms. In various neurodegenerative diseases, the mechanisms underlying HDAC6 interaction with other proteins seem to be a promising approach in understanding the modulation of HDAC6 activity.

  16. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

    SciTech Connect

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling; Shen, Jie

    2015-08-07

    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice.

  17. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production.

    PubMed

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling; Shen, Jie

    2015-08-07

    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. HDAC1-3 inhibitor MS-275 enhances IL10 expression in RAW264.7 macrophages and reduces cigarette smoke-induced airway inflammation in mice

    PubMed Central

    Leus, Niek G. J.; van den Bosch, Thea; van der Wouden, Petra E.; Krist, Kim; Ourailidou, Maria E.; Eleftheriadis, Nikolaos; Kistemaker, Loes E. M.; Bos, Sophie; Gjaltema, Rutger A. F.; Mekonnen, Solomon A.; Bischoff, Rainer; Gosens, Reinoud; Haisma, Hidde J.; Dekker, Frank J.

    2017-01-01

    Chronic obstructive pulmonary disease (COPD) constitutes a major health burden. Studying underlying molecular mechanisms could lead to new therapeutic targets. Macrophages are orchestrators of COPD, by releasing pro-inflammatory cytokines. This process relies on transcription factors such as NF-κB, among others. NF-κB is regulated by lysine acetylation; a post-translational modification installed by histone acetyltransferases and removed by histone deacetylases (HDACs). We hypothesized that small molecule HDAC inhibitors (HDACi) targeting class I HDACs members that can regulate NF-κB could attenuate inflammatory responses in COPD via modulation of the NF-κB signaling output. MS-275 is an isoform-selective inhibitor of HDAC1-3. In precision-cut lung slices and RAW264.7 macrophages, MS-275 upregulated the expression of both pro- and anti-inflammatory genes, implying mixed effects. Interestingly, anti-inflammatory IL10 expression was upregulated in these model systems. In the macrophages, this was associated with increased NF-κB activity, acetylation, nuclear translocation, and binding to the IL10 promoter. Importantly, in an in vivo model of cigarette smoke-exposed C57Bl/6 mice, MS-275 robustly attenuated inflammatory expression of KC and neutrophil influx in the lungs. This study highlights for the first time the potential of isoform-selective HDACi for the treatment of inflammatory lung diseases like COPD. PMID:28344354

  19. Inactivation of histone deacetylase 1 (HDAC1) but not HDAC2 is required for the glucocorticoid-dependent CCAAT/enhancer-binding protein α (C/EBPα) expression and preadipocyte differentiation.

    PubMed

    Kuzmochka, Claire; Abdou, Houssein-Salem; Haché, Robert J G; Atlas, Ella

    2014-12-01

    Several drugs currently used in the management of mood disorders, epilepsy (ie, valproic acid), or the control of inflammation (ie, corticosteroids) have been shown to promote visceral obesity in humans by increasing the number of newly formed adipocytes. Valproic acid is classified as a nonspecific histone deacetylase (HDAC) inhibitor, along with trichostatin A and butyric acid. In vitro experiments have demonstrated that such molecules greatly enhance the rate of preadipocyte differentiation, similarly to the effect of corticosteroids. The glucocorticoid receptor stimulates adipogenesis in part by enhancing the transcription of C/ebpa through the titration, and subsequent degradation, of HDAC1 from the C/ebpα promoter. There is, however, controversy in the literature as to the role of HDACs during adipogenesis. In this study, we sought to demonstrate, using 2 different strategies, the definite role of HDAC1 in adipogenesis. By using small interference RNA-mediated knockdown of HDAC1 and by generating an enzymatically inactive HDAC1D181A by site-directed mutagenesis, we were able to show that HDAC1, but not HDAC2, suppresses glucocorticoid receptor-potentiated preadipocyte differentiation by decreasing CCAAT/enhancer-binding protein (C/ebp)α and Pparγ expression levels at the onset of differentiation. Finally, we demonstrate that HDAC1D181A acts as a dominant negative mutant of HDAC1 during adipogenesis by modulating C/EBPβ transcriptional activity on the C/ebpα promoter.

  20. In Silico Approach to Finding New Active Compounds from Histone Deacetylase (HDAC) Family.

    PubMed

    Yanuar, Arry; Azminah, EmptyYN Y; Andika, EmptyYN Y; Erlina, Linda; Syahdi, Rezi Riadhi

    2016-01-01

    Histone Deacetylase (HDAC) enzymes in the human body play an important role in the transcriptional regulation of gene expression. In the last decade, HDAC inhibitors and activators have been explored and have become known as therapeutic agents for many diseases such as osteodystrophy, neurogenerative disorders, cardiomyopathy, cancer, and diabetes. In recent years, the development of HDAC inhibitors or activators to obtain new potent lead compounds has been conducted using in vitro, in vivo, and in silico methods. Some HDAC family inhibitors and activators have been discovered. But some compounds have limitations such as not selectively binding to one of the HDAC variants. At present, through bioinformation, HDAC family sequences have been revealed, and some in silico methods such as molecular modelling (homology modelling and pharmacophore modelling), virtual screening, and molecular dynamics are widely used to find and develop new potent and selective compounds. The main utilization of molecular modelling in this work is intended to complete the HDAC structure that partially lacks data regarding its amino acid monomer. Virtual screening methods are helpful in finding the best binding affinity of the test compounds. By molecular dynamic simulation, the temperature, time, and pressure can be adjusted to analyze the hydrogen bond. Combining these in silico approaches will be a more effective and efficient solution in finding new lead compounds for HDAC drug discovery research in the future.

  1. Energy metabolism regulated by HDAC inhibitor attenuates cardiac injury in hemorrhagic rat model

    PubMed Central

    Kuai, Qiyuan; Wang, Chunyan; Wang, Yanbing; Li, Weijing; Zhang, Gongqing; Qiao, Zhixin; He, Min; Wang, Xuanlin; Wang, Yu; Jiang, Xingwei; Su, Lihua; He, Yuezhong; Ren, Suping; Yu, Qun

    2016-01-01

    A disturbance of energy metabolism reduces cardiac function in acute severe hemorrhagic patients. Alternatively, adequate energy supply reduces heart failure and increases survival. However, the approach to regulating energy metabolism conductive to vital organs is limited, and the underlying molecular mechanism remains unknown. This study assesses the ability of histone deacetylase inhibitors (HDACIs) to preserve cardiac energy metabolism during lethal hemorrhagic injury. In the lethally hemorrhagic rat and hypoxic myocardial cells, energy metabolism and heart function were well maintained following HDACI treatment, as evident by continuous ATP production with normal cardiac contraction. Valproic acid (VPA) regulated the energy metabolism of hemorrhagic heart by reducing lactate synthesis and protecting the mitochondrial ultrastructure and respiration, which were attributable to the inhibition of lactate dehydrogenase A activity and the increased myeloid cell leukemia-1 (mcl-1) gene expression, ultimately facilitating ATP production and consumption. MCL-1, the key target of VPA, mediated this cardioprotective effect under acute severe hemorrhage conditions. Our results suggest that HDACIs promote cardioprotection by improving energy metabolism during hemorrhagic injury and could therefore be an effective strategy to counteract this process in the clinical setting. PMID:27910887

  2. Energy metabolism regulated by HDAC inhibitor attenuates cardiac injury in hemorrhagic rat model.

    PubMed

    Kuai, Qiyuan; Wang, Chunyan; Wang, Yanbing; Li, Weijing; Zhang, Gongqing; Qiao, Zhixin; He, Min; Wang, Xuanlin; Wang, Yu; Jiang, Xingwei; Su, Lihua; He, Yuezhong; Ren, Suping; Yu, Qun

    2016-12-02

    A disturbance of energy metabolism reduces cardiac function in acute severe hemorrhagic patients. Alternatively, adequate energy supply reduces heart failure and increases survival. However, the approach to regulating energy metabolism conductive to vital organs is limited, and the underlying molecular mechanism remains unknown. This study assesses the ability of histone deacetylase inhibitors (HDACIs) to preserve cardiac energy metabolism during lethal hemorrhagic injury. In the lethally hemorrhagic rat and hypoxic myocardial cells, energy metabolism and heart function were well maintained following HDACI treatment, as evident by continuous ATP production with normal cardiac contraction. Valproic acid (VPA) regulated the energy metabolism of hemorrhagic heart by reducing lactate synthesis and protecting the mitochondrial ultrastructure and respiration, which were attributable to the inhibition of lactate dehydrogenase A activity and the increased myeloid cell leukemia-1 (mcl-1) gene expression, ultimately facilitating ATP production and consumption. MCL-1, the key target of VPA, mediated this cardioprotective effect under acute severe hemorrhage conditions. Our results suggest that HDACIs promote cardioprotection by improving energy metabolism during hemorrhagic injury and could therefore be an effective strategy to counteract this process in the clinical setting.

  3. Protective role of sodium butyrate, a HDAC inhibitor on beta-cell proliferation, function and glucose homeostasis through modulation of p38/ERK MAPK and apoptotic pathways: study in juvenile diabetic rat.

    PubMed

    Khan, S; Jena, G B

    2014-04-25

    Type 1 diabetes (T1D) also known as juvenile diabetes is a chronic autoimmune disorder that precipitates in genetically susceptible individuals by environmental factors particularly during early age. Both genetic and epigenetic factors are implicated in the beta-cell development, proliferation, differentiation and function. Recent evidences suggested that there is a link between diabetes and histone deacetylases (HDACs), because HDAC inhibitors promote beta-cell development, proliferation and function as well as improve glucose homeostasis. Sodium butyrate (NaB) is a short chain fatty acid having HDAC inhibition activity. The present study was aimed to investigate the protective role of NaB treatment on the beta-cell proliferation, function and glucose homeostasis as well as apoptosis in juvenile diabetic rat. Diabetes was induced by single injection of STZ (60 mg/kg, i.p.) in chilled citrate buffer, while NaB (500 mg/kg/day) was administrated by i.p. route for 21 days as pre- and post-treatment schedule. Plasma glucose and insulin levels, HbA1c, glucose tolerance, apoptosis, and expression of proliferating cell nuclear antigen (PCNA), p38, p53, caspase-3, extracellular signal-regulated kinase-1/2 (ERK-1/2), forkhead box protein O1 (FOXO1) and insulin receptor substrate-1 (IRS-1) as well as histone acetylation were evaluated. NaB treatment decreased plasma glucose, HbA1c, beta-cell apoptosis and improved plasma insulin level and glucose homeostasis through HDAC inhibition and histone acetylation in diabetic animal as compared to control. NaB treatment improved the beta-cell proliferation, function and glucose homeostasis as well as reduced beta-cell apoptosis in juvenile diabetic rat by the modulation of p38/ERK MAPK and apoptotic pathway.

  4. Alkyl-Substituted Polyaminohydroxamic Acids: A Novel Class of Targeted Histone Deacetylase Inhibitors

    PubMed Central

    Varghese, Sheeba; Gupta, Deepak; Baran, Tiffany; Jiemjit, Anchalee; Gore, Steven D.; Casero, Robert A.; Woster, Patrick M.

    2013-01-01

    The reversible acetylation of histones is critical for regulation of eukaryotic gene expression. The histone deacetylase inhibitors trichostatin (TSA, 1), MS-275 (2) and suberoylanilide hydroxamic acid (SAHA, 3) arrest growth in transformed cells and in human tumor xenografts. However, 1–3 suffer from lack of specificity among the various HDAC isoforms, prompting us to design and synthesize polyaminohydroxamic acid (PAHA) derivatives 6–21. We felt that PAHAs would be selectively directed to chromatin and associated histones by the positively charged polyamine side chain. At 1 μM, compounds 12, 15 and 20 inhibited HDAC by 74.86, 59.99 and 73.85%, respectively. Although 20 was a less potent HDAC inhibitor than 1, it was more potent than 2, more effective as an initiator of histone hyperacetylation, and significantly more effective than 2 at re-expressing p21Waf1 in ML-1 leukemia cells. On the basis of these results, PAHAs 6–21 represent an important new chemical class of HDAC inhibitors. PMID:16190761

  5. Protein kinase and HDAC inhibitors from the endophytic fungus Epicoccum nigrum.

    PubMed

    El Amrani, Mustapha; Lai, Daowan; Debbab, Abdessamad; Aly, Amal H; Siems, Karsten; Seidel, Carole; Schnekenburger, Michael; Gaigneaux, Anthoula; Diederich, Marc; Feger, Daniel; Lin, Wenhan; Proksch, Peter

    2014-01-24

    A chemical investigation of the endophytic fungus Epicoccum nigrum isolated from leaves of Mentha suaveolens collected in Morocco resulted in the isolation of five new polyketides, epicocconigrones A and B (1 and 2), 3-methoxyepicoccone B (3), 3-methoxyepicoccone (4), and 2,3,4-trihydroxy-6-(methoxymethyl)-5-methylbenzaldehyde (5), together with five known compounds (6-10). The structures of the new compounds were unambiguously determined by extensive analysis of the 1D and 2D NMR and mass spectroscopic data. Compounds 1 and 10 showed potent inhibition of at least 15 protein kinases with IC50 values ranging from 0.07 to 9.00 μM. Moreover, compounds 1 and 10 inhibited histone deacetylase (HDAC) activities with IC50 values of 9.8 and 14.2 μM, respectively. A preliminary structure-activity relationship is discussed. Interestingly, compounds 1 and 10 exert mainly cytostatic effects in human lymphoma RAJI and U-937 cell lines.

  6. HDAC 3-selective inhibitor RGFP966 demonstrates anti-inflammatory properties in RAW 264.7 macrophages and mouse precision-cut lung slices by attenuating NF-κB p65 transcriptional activity

    PubMed Central

    Leus, Niek G.J.; van der Wouden, Petra E.; van den Bosch, Thea; Hooghiemstra, Wouter T.R.; Ourailidou, Maria E.; Kistemaker, Loes E.M.; Bischoff, Rainer; Gosens, Reinoud; Haisma, Hidde J.; Dekker, Frank J.

    2016-01-01

    The increasing number of patients suffering from chronic obstructive pulmonary disease (COPD) represents a major and increasing health problem. Therefore, novel therapeutic approaches are needed. Class I HDACs 1, 2 and 3 play key roles in the regulation of inflammatory gene expression with a particular pro-inflammatory role for HDAC 3. HDAC 3 has been reported to be an important player in inflammation by deacetylating NF-κB p65, which has been implicated in the pathology of COPD. Here, we applied the pharmacological HDAC 3-selective inhibitor RGFP966, which attenuated pro-inflammatory gene expression in models for inflammatory lung diseases. Consistent with this, a robust decrease of the transcriptional activity of NF-κB p65 was observed. HDAC 3 inhibition affected neither the acetylation status of NF-κB p65 nor histone H3 or histone H4. This indicates that HDAC 3 inhibition does not inhibit NF-κB p65 transcriptional activity by affecting its deacetylation but rather by inhibiting enzymatic activity of HDAC 3. Taken together, our findings indicate that pharmacological HDAC 3-selective inhibition by inhibitors such as RGFP966 may provide a novel and effective approach toward development of therapeutics for inflammatory lung diseases. PMID:26993378

  7. Tubastatin A, an HDAC6 inhibitor, alleviates stroke-induced brain infarction and functional deficits: potential roles of α-tubulin acetylation and FGF-21 up-regulation

    PubMed Central

    Wang, Zhifei; Leng, Yan; Wang, Junyu; Liao, Hsiao-Mei; Bergman, Joel; Leeds, Peter; Kozikowski, Alan; Chuang, De-Maw

    2016-01-01

    Histone deacetylase (HDAC) 6 exists exclusively in cytoplasm and deacetylates cytoplasmic proteins such as α-tubulin. HDAC6 dysfunction is associated with several pathological conditions in the central nervous system. This study investigated the beneficial effects of tubastatin A (TubA), a novel specific HDAC6 inhibitor, in a rat model of transient middle cerebral artery occlusion (MCAO) and an in vitro model of excitotoxicity. Post-ischemic TubA treatment robustly improved functional outcomes, reduced brain infarction, and ameliorated neuronal cell death in MCAO rats. These beneficial effects lasted at least three days after MCAO. Notably, when given at 24 hours after MCAO, TubA still exhibited significant protection. Levels of acetylated α-tubulin were decreased in the ischemic hemisphere on Days 1 and 3 after MCAO, and were significantly restored by TubA. MCAO markedly downregulated fibroblast growth factor-21 (FGF-21) and TubA significantly reversed this downregulation. TubA also mitigated impaired FGF-21 signaling in the ischemic hemisphere, including up-regulating β-Klotho, and activating ERK and Akt/GSK-3β signaling pathways. In addition, both TubA and exogenous FGF-21 conferred neuroprotection and restored mitochondrial trafficking in rat cortical neurons against glutamate-induced excitotoxicity. Our findings suggest that the neuroprotective effects of TubA likely involve HDAC6 inhibition and the subsequent up-regulation of acetylated α-tubulin and FGF-21. PMID:26790818

  8. HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation

    PubMed Central

    Hong, Young Bin; Choi, Heesun; Kim, Jisoo; Choi, Hyunjung; Mook-Jung, Inhee; Ha, Nina; Kyung, Jangbeen; Koo, Soo Kyung

    2016-01-01

    The Charcot-Marie-Tooth disease 2F (CMT2F) and distal hereditary motor neuropathy 2B (dHMN2B) are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1) gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs) of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy. PMID:28105056

  9. HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation.

    PubMed

    Kim, Ji-Yon; Woo, So-Youn; Hong, Young Bin; Choi, Heesun; Kim, Jisoo; Choi, Hyunjung; Mook-Jung, Inhee; Ha, Nina; Kyung, Jangbeen; Koo, Soo Kyung; Jung, Sung-Chul; Choi, Byung-Ok

    2016-01-01

    The Charcot-Marie-Tooth disease 2F (CMT2F) and distal hereditary motor neuropathy 2B (dHMN2B) are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1) gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs) of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.

  10. Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

    PubMed

    Ning, Chengqing; Bi, Yanjing; He, Yujun; Huang, WenYuan; Liu, Lifei; Li, Yi; Zhang, Sihan; Liu, Xiaoyu; Yu, Niefang

    2013-12-01

    A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 μM, respectively.

  11. Histone deacetylase inhibitor valproic acid affects plasmacytoid dendritic cells phenotype and function.

    PubMed

    Arbez, Jessy; Lamarthée, Baptiste; Gaugler, Béatrice; Saas, Philippe

    2014-08-01

    Plasmacytoid dendritic cells (PDC) represent a rare subset of dendritic cells specialized in the production of type I IFN in response to microbial pathogens. Recent data suggested that histone deacetylase (HDAC) inhibitors possess potent immunomodulatory properties both in vitro and in vivo. In this study, we assayed the ability of the HDAC inhibitor, valproic acid (VPA), to influence the phenotype and functional properties of human PDC isolated from peripheral blood. We showed that VPA inhibited the production of IFN-α and the proinflammatory cytokines TNF-α and IL-6 by CpG-activated PDC. VPA also affected the phenotype of PDC by reducing the expression of costimulatory molecules induced by CpG activation. Moreover, VPA reduced the capacity of CpG-stimulated PDC to promote CD4(+) T cell proliferation and IFN-γ production, while enhancing the proportion of IL-10 positive T cells. These results suggest that HDAC inhibition by VPA alters essential human PDC functions, highlighting the need for monitoring immune functions in cancer patients receiving HDAC inhibitors, but also making these drugs attractive therapies in inflammatory, and autoimmune diseases implicating PDC. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. In vitro cytotoxicity evaluation of HDAC inhibitor Apicidin in pancreatic carcinoma cells subsequent time and dose dependent treatment.

    PubMed

    Bauden, Monika; Tassidis, Helena; Ansari, Daniel

    2015-07-02

    Apicidin is a potent histone deacetylase inhibitor (HDACI) that selectively binds to histone deacetylases (HDACs) class I and interferes with the deacetylation process, which results in modification of acetylation level of cellular proteins. The aim of the study was to investigate the potential time and dose dependent cytotoxicity of the test compound, Apicidin, in pancreatic cancer cells Capan-1 and Panc-1 as well as estimate maximal tolerable dose (MTD) of the test agent and determine EC50 using four complementary colorimetric cytotoxicity or viability assays. The cells were treated with increasing concentrations of Apicidin (0-5000nM) for 2, 4 and 6h (short term exposure) or 24, 48 and 72h (long term exposure) before conducting cytotoxic analyses with lactate dehydrogenase assay or viability analyses with sulforhodamine B (SRB), methyl tetrazolium (MTT) and crystal violet (CV) assays. In order to investigate whether Apicidin irreversibly affects the cells already during the short term exposure, the medium containing Apicidin was removed and replaced with fresh culturing medium after 6h of treatment. The cells were then incubated for additional 24, 48 or 72h before carrying out the analysis. The results obtained from cytotoxicity and viability assays indicated, that Apicidin was well tolerated by both cell lines at concentrations below 100nM at any given time point and at all applied concentrations during the short term (6h or less) treatment. Continuous prolonged term exposures (48h or greater) of the cells to Apicidin with concentration exceeding 100nM resulted in significantly increasing cytotoxicity and sustained significant loss of cell viability. Moreover, long term exposure of pancreatic cancer cells Capan-1 and Panc-1 to Apicidin concentrations exceeding 100nM showed an initial anti-proliferative effect before cytotoxicity onset. In summary, MTD was exposure time dependent and estimated to 100nM for long term treatment and to at least 5000nM for treatment

  13. Combined autophagy and HDAC inhibition: a phase I safety, tolerability, pharmacokinetic, and pharmacodynamic analysis of hydroxychloroquine in combination with the HDAC inhibitor vorinostat in patients with advanced solid tumors.

    PubMed

    Mahalingam, Devalingam; Mita, Monica; Sarantopoulos, John; Wood, Leslie; Amaravadi, Ravi K; Davis, Lisa E; Mita, Alain C; Curiel, Tyler J; Espitia, Claudia M; Nawrocki, Steffan T; Giles, Francis J; Carew, Jennifer S

    2014-08-01

    We previously reported that inhibition of autophagy significantly augmented the anticancer activity of the histone deacetylase (HDAC) inhibitor vorinostat (VOR) through a cathepsin D-mediated mechanism. We thus conducted a first-in-human study to investigate the safety, preliminary efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of the combination of the autophagy inhibitor hydroxychloroquine (HCQ) and VOR in patients with advanced solid tumors. Of 27 patients treated in the study, 24 were considered fully evaluable for study assessments and toxicity. Patients were treated orally with escalating doses of HCQ daily (QD) (d 2 to 21 of a 21-d cycle) in combination with 400 mg VOR QD (d one to 21). Treatment-related adverse events (AE) included grade 1 to 2 nausea, diarrhea, fatigue, weight loss, anemia, and elevated creatinine. Grade 3 fatigue and/or myelosuppression were observed in a minority of patients. Fatigue and gastrointestinal AE were dose-limiting toxicities. Six-hundred milligrams HCQ and 400 mg VOR was established as the maximum tolerated dose and recommended phase II regimen. One patient with renal cell carcinoma had a confirmed durable partial response and 2 patients with colorectal cancer had prolonged stable disease. The addition of HCQ did not significantly impact the PK profile of VOR. Treatment-related increases in the expression of CDKN1A and CTSD were more pronounced in tumor biopsies than peripheral blood mononuclear cells. Based on the safety and preliminary efficacy of this combination, additional clinical studies are currently being planned to further investigate autophagy inhibition as a new approach to increase the efficacy of HDAC inhibitors.

  14. HDAC1 and HDAC2 collectively regulate intestinal stem cell homeostasis.

    PubMed

    Zimberlin, Cheryl D; Lancini, Cesare; Sno, Rachel; Rosekrans, Sanne L; McLean, Chelsea M; Vlaming, Hanneke; van den Brink, Gijs R; Bots, Michael; Medema, Jan Paul; Dannenberg, Jan-Hermen

    2015-05-01

    Histone deacetylases (HDACs) are posttranslational modifiers that deacetylate proteins. Despite their crucial role in numerous biological processes, the use of broad-range HDAC inhibitors (HDACi), has shown clinical efficacy. However, undesired side effects highlight the necessity to better understand the biology of different HDACs and target the relevant HDACs. Using a novel mouse model, in which HDAC1 and HDAC2 can be simultaneously deleted in the intestine of adult mice, we show that the simultaneous deletion of HDAC1 and HDAC2 leads to a rapid loss of intestinal homeostasis. Importantly, this deletion cannot be sustained, and 8 days after initial ablation, stem cells that have escaped HDAC1 or HDAC2 deletion swiftly repopulate the intestinal lining. In vitro ablation of HDAC1 and HDAC2 using intestinal organoid cultures resulted in a down-regulation of multiple intestinal stem cell markers and functional loss of clonogenic capacity. Importantly, treatment of wild-type organoids with class I-specific HDACi MS-275 also induced a similar loss of stemness, providing a possible rationale for the gastrointestinal side effects often observed in HDACi-treated patients. In conclusion, these data show that HDAC1 and HDAC2 have a redundant function and are essential to maintain intestinal homeostasis.

  15. Vorinostat, an HDAC inhibitor attenuates epidermoid squamous cell carcinoma growth by dampening mTOR signaling pathway in a human xenograft murine model

    SciTech Connect

    Kurundkar, Deepali; Srivastava, Ritesh K.; Chaudhary, Sandeep C.; Ballestas, Mary E.; Kopelovich, Levy; Elmets, Craig A.; Athar, Mohammad

    2013-01-15

    Histone deacetylase (HDAC) inhibitors are potent anticancer agents and show efficacy against various human neoplasms. Vorinostat is a potent HDAC inhibitor and has shown potential to inhibit growth of human xenograft tumors. However, its effect on the growth of skin neoplasm remains undefined. In this study, we show that vorinostat (2 μM) reduced expression of HDAC1, 2, 3, and 7 in epidermoid carcinoma A431 cells. Consistently, it increased acetylation of histone H3 and p53. Vorinostat (100 mg/kg body weight, IP) treatment reduced human xenograft tumor growth in highly immunosuppressed nu/nu mice. Histologically, the vorinostat-treated tumor showed features of well-differentiation with large necrotic areas. Based on proliferating cell nuclear antigen (PCNA) staining and expression of cyclins D1, D2, E, and A, vorinostat seems to impair proliferation by down-regulating the expression of these proteins. However, it also induced apoptosis. The mechanism by which vorinostat blocks proliferation and makes tumor cells prone to apoptosis, involved inhibition of mTOR signaling which was accompanied by reduction in cell survival AKT and extracellular-signal regulated kinase (ERK) signaling pathways. Our data provide a novel mechanism-based therapeutic intervention for cutaneous squamous cell carcinoma (SCC). Vorinostat may be utilized to cure skin neoplasms in organ transplant recipient (OTR). These patients have high morbidity and surgical removal of these lesions which frequently develop in these patients, is difficult. -- Highlights: ► Vorinostat reduces SCC growth in a xenograft murine model. ► Vorinostat dampens proliferation and induces apoptosis in tumor cells. ► Diminution in mTOR, Akt and ERK signaling underlies inhibition in proliferation. ► Vorinostat by inhibiting HDACs inhibits epithelial–mesenchymal transition.

  16. HDAC Inhibitor-Mediated Epigenetic Regulation of Glaucoma-Associated TGFβ2 in the Trabecular Meshwork

    PubMed Central

    Bermudez, Jaclyn Y.; Webber, Hannah C.; Patel, Gaurang C.; Liu, Xiangyang; Cheng, Yi-Qiang; Clark, Abbot F.; Mao, Weiming

    2016-01-01

    Purpose Elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) results from glaucomatous damage to the trabecular meshwork (TM). The glaucoma-associated factor TGFβ2 is increased in aqueous humor and TM of POAG patients. We hypothesize that histone acetylation has a role in dysregulated TGFβ2 expression. Methods Protein acetylation was compared between nonglaucomatous TM (NTM) and glaucomatous TM (GTM) cells using Western immunoblotting (WB). Nonglaucomatous TM cells were treated with 10 nM thailandepsin-A (TDP-A), a potent histone deacetylase inhibitor for 4 days. Total and nuclear proteins, RNA, and nuclear protein-DNA complexes were harvested for WB, quantitative PCR (qPCR), and chromatin immunoprecipitation (ChIP) assays, respectively. Paired bovine eyes were perfused with TDP-A versus DMSO, or TDP-A versus TDP-A plus the TGFβ pathway inhibitor LY364947 for 5 to 9 days. Intraocular pressure, TM, and perfusate proteins were compared. Results We found increased acetylated histone 3 and total protein acetylation in the GTM cells and TDP-A treated NTM cells. Chromatin immunoprecipitation assays showed that TDP-A induced histone hyperacetylation associated with the TGFβ2 promoter. This change of acetylation significantly increased TGFβ2 mRNA and protein expression in NTM cells. In perfusion-cultured bovine eyes, TDP-A increased TGFβ2 in the perfusate as well as elevated IOP. Histologic and immunofluorescent analyses showed increased extracellular matrix and cytoskeletal proteins in the TM of TDP-A treated bovine eyes. Cotreatment with the TGFβ pathway inhibitor LY364947 blocked TDP-A–induced ocular hypertension. Conclusions Our results suggest that histone acetylation has an important role in increased expression of the glaucoma-associated factor TGFβ2. Histone hyperacetylation may be the initiator of glaucomatous damage to the TM. PMID:27403998

  17. HDAC inhibitor-dependent transcriptome and memory reinstatement in cognitive decline models.

    PubMed

    Benito, Eva; Urbanke, Hendrik; Ramachandran, Binu; Barth, Jonas; Halder, Rashi; Awasthi, Ankit; Jain, Gaurav; Capece, Vincenzo; Burkhardt, Susanne; Navarro-Sala, Magdalena; Nagarajan, Sankari; Schütz, Anna-Lena; Johnsen, Steven A; Bonn, Stefan; Lührmann, Reinhardt; Dean, Camin; Fischer, André

    2015-09-01

    Aging and increased amyloid burden are major risk factors for cognitive diseases such as Alzheimer's disease (AD). Effective therapies for these diseases are lacking. Here, we evaluated mouse models of age-associated memory impairment and amyloid deposition to study transcriptome and cell type-specific epigenome plasticity in the brain and peripheral organs. We determined that aging and amyloid pathology are associated with inflammation and impaired synaptic function in the hippocampal CA1 region as the result of epigenetic-dependent alterations in gene expression. In both amyloid and aging models, inflammation was associated with increased gene expression linked to a subset of transcription factors, while plasticity gene deregulation was differentially mediated. Amyloid pathology impaired histone acetylation and decreased expression of plasticity genes, while aging altered H4K12 acetylation-linked differential splicing at the intron-exon junction in neurons, but not nonneuronal cells. Furthermore, oral administration of the clinically approved histone deacetylase inhibitor vorinostat not only restored spatial memory, but also exerted antiinflammatory action and reinstated epigenetic balance and transcriptional homeostasis at the level of gene expression and exon usage. This study provides a systems-level investigation of transcriptome plasticity in the hippocampal CA1 region in aging and AD models and suggests that histone deacetylase inhibitors should be further explored as a cost-effective therapeutic strategy against age-associated cognitive decline.

  18. How to Distinguish Between the Activity of HDAC1-3 and HDAC6 with Western Blot.

    PubMed

    Beyer, Mandy; Kiweler, Nicole; Mahboobi, Siavosh; Krämer, Oliver H

    2017-01-01

    Histone deacetylases (HDACs) catalyze the deacetylation of lysine residues in their target proteins. This biochemical modification can have profound effects on the functions of these proteins and a dysregulation of HDAC activity contributes to severe diseases, including neoplastic transformation. In the following chapter, we present a strategy that allows to distinguish between the inhibition of the class I HDACs HDAC1, 2, and 3 and of the class IIb HDAC HDAC6. This method is based on Western blot and relies on the detection of hyperacetylated substrates of class I or class IIb HDACs in lysates from cells that were treated with histone deacetylase inhibitors (HDACi).

  19. HDAC1 regulates fear extinction in mice.

    PubMed

    Bahari-Javan, Sanaz; Maddalena, Andrea; Kerimoglu, Cemil; Wittnam, Jessica; Held, Torsten; Bähr, Mathias; Burkhardt, Susanne; Delalle, Ivanna; Kügler, Sebastian; Fischer, Andre; Sananbenesi, Farahnaz

    2012-04-11

    Histone acetylation has been implicated with the pathogenesis of neuropsychiatric disorders and targeting histone deacetylases (HDACs) using HDAC inhibitors was shown to be neuroprotective and to initiate neuroregenerative processes. However, little is known about the role of individual HDAC proteins during the pathogenesis of brain diseases. HDAC1 was found to be upregulated in patients suffering from neuropsychiatric diseases. Here, we show that virus-mediated overexpression of neuronal HDAC1 in the adult mouse hippocampus specifically affects the extinction of contextual fear memories, while other cognitive abilities were unaffected. In subsequent experiments we show that under physiological conditions, hippocampal HDAC1 is required for extinction learning via a mechanism that involves H3K9 deacetylation and subsequent trimethylation of target genes. In conclusion, our data show that hippocampal HDAC1 has a specific role in memory function.

  20. HDAC inhibitor AR-42 decreases CD44 expression and sensitizes myeloma cells to lenalidomide

    PubMed Central

    Sborov, Douglas W.; Cascione, Luciano; Radomska, Hanna S.; Smith, Emily; Stiff, Andrew; Consiglio, Jessica; Caserta, Enrico; Rizzotto, Lara; Zanesi, Nicola; Stefano, Volinia; Kaur, Balveen; Mo, Xiaokui; Byrd, John C.; Efebera, Yvonne A.

    2015-01-01

    Multiple myeloma (MM) is a hematological malignancy of plasma cells in the bone marrow. Despite multiple treatment options, MM is inevitably associated with drug resistance and poor outcomes. Histone deacetylase inhibitors (HDACi's) are promising novel chemotherapeutics undergoing evaluation in clinical trials for the potential treatment of patients with MM. Although in preclinical studies HDACi's have proven anti-myeloma activity, but in the clinic single-agent HDACi treatments have been limited due to low tolerability. Improved clinical outcomes were reported only when HDACi's were combined with other drugs. Here, we show that a novel pan-HDACi AR-42 downregulates CD44, a glycoprotein that has been associated with lenalidomide and dexamethasone resistance in myeloma both in vitro and in vivo. We also show that this CD44 downregulation is in part mediated by miR-9–5p, targeting insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which directly binds to CD44 mRNA and increases its stability. Importantly, we also demonstrate that AR-42 enhances anti-myeloma activity of lenalidomide in primary MM cells isolated from lenalidomide resistant patients and in in vivo MM mouse model. Thus, our findings shed light on potential novel combinatorial therapeutic approaches modulating CD44 expression, which may help overcome lenalidomide resistance in myeloma patients. PMID:26429859

  1. c-Myc Modulation and Acetylation Is a Key HDAC Inhibitor Target in Cancer.

    PubMed

    Nebbioso, Angela; Carafa, Vincenzo; Conte, Mariarosaria; Tambaro, Francesco Paolo; Abbondanza, Ciro; Martens, Joost; Nees, Matthias; Benedetti, Rosaria; Pallavicini, Isabella; Minucci, Saverio; Garcia-Manero, Guillermo; Iovino, Francesco; Lania, Gabriella; Ingenito, Concetta; Belsito Petrizzi, Valeria; Stunnenberg, Hendrik G; Altucci, Lucia

    2017-05-15

    Purpose: Histone deacetylase inhibitors (HDACi) are promising anticancer drugs. Although some HDACi have entered the clinic, the mechanism(s) underlying their tumor selectivity are poorly understood.Experimental Design and Results: Using gene expression analysis, we define a core set of six genes commonly regulated in acute myeloid leukemia (AML) blasts and cell lines. MYC, the most prominently modulated, is preferentially altered in leukemia. Upon HDACi treatment, c-Myc is acetylated at lysine 323 and its expression decreases, leading to TRAIL activation and apoptosis. c-Myc binds to the TRAIL promoter on the proximal GC box through SP1 or MIZ1, impairing TRAIL activation. HDACi exposure triggers TRAIL expression, altering c-Myc-TRAIL binding. These events do not occur in normal cells. Excitingly, this inverse correlation between TRAIL and c-Myc is supported by HDACi treatment ex vivo of AML blasts and primary human breast cancer cells. The predictive value of c-Myc to HDACi responsiveness is confirmed in vivo in AML patients undergoing HDACi-based clinical trials.Conclusions: Collectively, our findings identify a key role for c-Myc in TRAIL deregulation and as a biomarker of the anticancer action of HDACi in AML. The potential improved patient stratification could pave the way toward personalized therapies. Clin Cancer Res; 23(10); 2542-55. ©2016 AACR. ©2016 American Association for Cancer Research.

  2. HDAC inhibitor AR-42 decreases CD44 expression and sensitizes myeloma cells to lenalidomide.

    PubMed

    Canella, Alessandro; Cordero Nieves, Hector; Sborov, Douglas W; Cascione, Luciano; Radomska, Hanna S; Smith, Emily; Stiff, Andrew; Consiglio, Jessica; Caserta, Enrico; Rizzotto, Lara; Zanesi, Nicola; Stefano, Volinia; Kaur, Balveen; Mo, Xiaokui; Byrd, John C; Efebera, Yvonne A; Hofmeister, Craig C; Pichiorri, Flavia

    2015-10-13

    Multiple myeloma (MM) is a hematological malignancy of plasma cells in the bone marrow. Despite multiple treatment options, MM is inevitably associated with drug resistance and poor outcomes. Histone deacetylase inhibitors (HDACi's) are promising novel chemotherapeutics undergoing evaluation in clinical trials for the potential treatment of patients with MM. Although in preclinical studies HDACi's have proven anti-myeloma activity, but in the clinic single-agent HDACi treatments have been limited due to low tolerability. Improved clinical outcomes were reported only when HDACi's were combined with other drugs. Here, we show that a novel pan-HDACi AR-42 downregulates CD44, a glycoprotein that has been associated with lenalidomide and dexamethasone resistance in myeloma both in vitro and in vivo. We also show that this CD44 downregulation is in part mediated by miR-9-5p, targeting insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which directly binds to CD44 mRNA and increases its stability. Importantly, we also demonstrate that AR-42 enhances anti-myeloma activity of lenalidomide in primary MM cells isolated from lenalidomide resistant patients and in in vivo MM mouse model. Thus, our findings shed light on potential novel combinatorial therapeutic approaches modulating CD44 expression, which may help overcome lenalidomide resistance in myeloma patients.

  3. Binding Ensemble PROfiling with (F)photoaffinity Labeling (BEProFL) Approach: Mapping the Binding Poses of HDAC8 Inhibitors

    PubMed Central

    He, Bai; Velaparthi, Subash; Pieffet, Gilles; Pennington, Chris; Mahesh, Aruna; Holzle, Denise L.; Brunsteiner, Michael; van Breemen, Richard; Blond, Sylvie Y.; Petukhov, Pavel A.

    2009-01-01

    A Binding Ensemble PROfiling with (F)photoaffinity Labeling (BEProFL) approach that utilizes photolabeling of HDAC8 with a probe containing a UV-activated aromatic azide, mapping the covalent modifications by liquid chromatography-tandem mass-spectrometry, and a computational method to characterize the multiple binding poses of the probe is described. Using the BEProFL approach two distinct binding poses of the HDAC8 probe were identified. The data also suggest that an “upside-down” pose with the surface binding group of the probe bound in an alternative pocket near the catalytic site may contribute to the binding. PMID:19886628

  4. REPRESSION OF 15-HYDROXYPROSTAGLANDIN DEHYDROGENASE INVOLVES HDAC2 AND SNAIL IN COLORECTAL CANCER

    PubMed Central

    Backlund, Michael G.; Mann, Jason R.; Holla, Vijaykumar R.; Shi, Qiong; Daikoku, Takikoku; Dey, Sudhansu K.; DuBois, Raymond N.

    2008-01-01

    Prostaglandin E2 (PGE2) promotes cancer progression by modulating proliferation, apoptosis, angiogenesis and the immune response. Enzymatic degradation of PGE2 involves the NAD+–dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH). Recent reports have shown a marked diminution of 15-PGDH expression in colorectal carcinomas. We report here that treatment of colorectal cancer (CRC) cells with histone deacetylase (HDAC) inhibitors, including sodium butyrate (NaB) and valproic acid (VPA), induces 15-PGDH expression. Additionally, we demonstrate that pre-treatment of CRC cells with HDAC inhibitors can block EGF or Snail-mediated transcriptional repression of 15-PGDH. We demonstrate an interaction between Snail and HDAC2 and the binding of HDAC2 to the 15-PGDH promoter. In vivo we observe increased Hdac2 expression in Apc-deficient mouse adenomas, which inversely correlated with loss of 15-Pgdh expression. Finally, in human colon cancers, elevated HDAC expression correlated with down-regulation of 15-PGDH. These data suggest that class I histone deacetylases, specifically HDAC2, and the transcriptional repressor Snail, play an central role in the suppression 15-PGDH expression. These results also provide a COX2-independent mechanism to explain increased PGE2 levels that contribute to progression of colorectal cancer. PMID:19010907

  5. In vitro and in vivo interactions between the HDAC6 inhibitor ricolinostat (ACY1215) and the irreversible proteasome inhibitor carfilzomib in non-Hodgkin lymphoma cells.

    PubMed

    Dasmahapatra, Girija; Patel, Hiral; Friedberg, Johnathan; Quayle, Steven N; Jones, Simon S; Grant, Steven

    2014-12-01

    Interactions between the HDAC6 inhibitor ricolinostat (ACY1215) and the irreversible proteasome inhibitor carfilzomib were examined in non-Hodgkin lymphoma (NHL) models, including diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), and double-hit lymphoma cells. Marked in vitro synergism was observed in multiple cell types associated with activation of cellular stress pathways (e.g., JNK1/2, ERK1/2, and p38) accompanied by increases in DNA damage (γH2A.X), G2-M arrest, and the pronounced induction of mitochondrial injury and apoptosis. Combination treatment with carfilzomib and ricolinostat increased reactive oxygen species (ROS), whereas the antioxidant TBAP attenuated DNA damage, JNK activation, and cell death. Similar interactions occurred in bortezomib-resistant and double-hit DLBCL, MCL, and primary DLBCL cells, but not in normal CD34(+) cells. However, ricolinostat did not potentiate inhibition of chymotryptic activity by carfilzomib. shRNA knockdown of JNK1 (but not MEK1/2), or pharmacologic inhibition of p38, significantly reduced carfilzomib-ricolinostat lethality, indicating a functional contribution of these stress pathways to apoptosis. Combined exposure to carfilzomib and ricolinostat also markedly downregulated the cargo-loading protein HR23B. Moreover, HR23B knockdown significantly increased carfilzomib- and ricolinostat-mediated lethality, suggesting a role for this event in cell death. Finally, combined in vivo treatment with carfilzomib and ricolinostat was well tolerated and significantly suppressed tumor growth and increased survival in an MCL xenograft model. Collectively, these findings indicate that carfilzomib and ricolinostat interact synergistically in NHL cells through multiple stress-related mechanisms, and suggest that this strategy warrants further consideration in NHL.

  6. HDAC inhibitor-loaded bone cement for advanced local treatment of osteosarcoma and chondrosarcoma.

    PubMed

    Tonak, Marcus; Becker, Marc; Graf, Claudine; Eckhard, Lukas; Theobald, Matthias; Rommens, Pol-Maria; Wehler, Thomas C; Proschek, Dirk

    2014-11-01

    The treatment of osteosarcoma, especially wide resection, is challenging. An additional local drug therapy after resection using anti-neoplastic bone cement (Polymethylmethacrylate (PMMA)) could help improve the outcome of therapy. In this study, we evaluated the effects of PMMA loaded with valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) on the cell activity of a SaOs-2 cell culture, as well as the elution rate of the drugs out of the bone cement. In our experiments, we used the SaOs-2 osteosarcoma and the SW1353 chondrosarcoma cell line. Bone cement clots (5 g) were prepared and loaded with different drug concentrations of VPA (25 mg and 50 mg) and SAHA (1 mg, 2.5 mg and 5 mg). Two control groups were established, one with a native cement clot, the other with human mesenchymal stem cells, in order to evaluate toxicity on non tumor-cells. Cell activity was measured using an Alamar Blue assay on days 1, 2, 3, 4 and 7. The cement clots were additionally examined in a material testing unit for biomechanical and structural changes. Tumor cells showed a significant and complete reduction of activity under therapy with VPA and SAHA. Drug release of VPA was extensive between days 0 and 3 and decreased progressively to day 7. Cumulative drug concentration in the medium continuously increased. Biomechanical testing of the cement clots showed no differences in stability and architecture compared to the control group. SaOs-2 and SW1353 cells with medium from native cement clots without drug therapy presented a cell activity of 100% in all groups and during all measurements. Human mesenchymal stem cells were not significantly affected during therapy with VPA and low concentrations of SAHA. In contrast, cell activity of human mesenchymal stem cells was significantly reduced under therapy with higher concentrations of SAHA, with an approximately linear decrease between days 0-3 and a rapidly decreasing activity between days 4-7. A local cytotoxic therapy in the

  7. Role of 5'TG3'-interacting factors (TGIFs) in Vorinostat (HDAC inhibitor)-mediated Corneal Fibrosis Inhibition.

    PubMed

    Sharma, Ajay; Sinha, Nishant R; Siddiqui, Saad; Mohan, Rajiv R

    2015-01-01

    We have previously reported that vorinostat, an FDA-approved, clinically used histone deacetylase (HDAC) inhibitor, attenuates corneal fibrosis in vivo in rabbits by blocking transforming growth factor β (TGFβ). The 5'TG3'-interacting factors (TGIFs) are transcriptional repressors of TGFβ1 signaling via the Smad pathway. The present study was designed to explore the expression of TGIFs in human corneal fibroblasts and to investigate their role in mediating the antifibrotic effect of vorinostat. Human corneal fibroblast cultures were generated from donor corneas. RNA isolation, cDNA preparation, and PCR were performed to detect the presence of TGIF1 and TGIF2 transcripts. The cultures were exposed to vorinostat (2.5 µM) to test its effect on TGIF mRNA and protein levels using qPCR and immunoblotting. Myofibroblast formation was induced with TGFβ1 (5 ng/ml) treatment under serum-free conditions. The changes in fibrosis parameters were quantified by measuring fibrosis marker α-smooth muscle actin (αSMA) mRNA and protein levels with qPCR, immunostaining, and immunoblotting. Smad2/3/4 and TGIF knockdowns were performed using pre-validated RNAi/siRNAs and a commercially available transfection reagent. Human corneal fibroblasts showed the expression of TGIF1 and TGIF2. Vorinostat (2.5 µM) caused a 2.8-3.3-fold increase in TGIF1 and TGIF2 mRNA levels and a 1.4-1.8-fold increase in TGIF1 and TGIF2 protein levels. Vorinostat treatment also caused a significant increase in acetylhistone H3 and acetylhistone H4. Vorinostat-induced increases in TGIF1 and TGIF2 were accompanied by a concurrent decrease in corneal fibrosis, as indicated by a decrease in αSMA mRNA by 83±7.7% and protein levels by 97±5%. The RNAi-mediated knockdown of Smad2, Smad3, and Smad4 markedly attenuated TGFβ1-evoked transdifferentiation of fibroblasts to myofibroblasts. The siRNA-mediated knockdown of TGIF1 and TGIF2 neutralized vorinostat-evoked decreases in αSMA mRNA by 31%-45% and protein

  8. Stereoselective HDAC inhibition from cysteine-derived zinc-binding groups.

    PubMed

    Butler, Kyle V; He, Rong; McLaughlin, Kathryn; Vistoli, Giulio; Langley, Brett; Kozikowski, Alan P

    2009-08-01

    A series of small-molecule histone deacetylase (HDAC) inhibitors, which feature zinc binding groups derived from cysteine, were synthesized. These inhibitors were tested against multiple HDAC isoforms, and the most potent, compound 10, was determined to have IC(50) values below 1 microM. The compounds were also tested in a cellular assay of oxidative stress-induced neurodegeneration. Many of the inhibitors gave near-complete protection against cell death at 10 microM without the neurotoxicity seen with hydroxamic acid-based inhibitors, and were far more neuroprotective than HDAC inhibitors currently in clinical trials. Both enantiomers of cysteine were used in the synthesis of a variety of novel zinc-binding groups (ZBGs). Derivatives of L-cysteine were active in the HDAC inhibition assays, while the derivatives of D-cysteine were inactive. Notably, the finding that both the D- and L-cysteine derivatives were active in the neuroprotection assays suggests that multiple mechanisms are working to protect the neurons from cell death. Molecular modeling was employed to investigate the differences in inhibitory activity between the HDAC inhibitors generated from the two enantiomeric forms of cysteine.

  9. Potential advantages of CUDC-101, a multitargeted HDAC, EGFR, and HER2 inhibitor, in treating drug resistance and preventing cancer cell migration and invasion.

    PubMed

    Wang, Jing; Pursell, Natalie W; Samson, Maria Elena S; Atoyan, Ruzanna; Ma, Anna W; Selmi, Abdelkader; Xu, Wanlu; Cai, Xiong; Voi, Maurizio; Savagner, Pierre; Lai, Cheng-Jung

    2013-06-01

    CUDC-101 is a novel, small-molecule, anticancer agent targeting histone deacetylase (HDAC), EGF receptor (EGFR), and HER2. It is currently in phase I clinical development in patients with solid tumors. Previously, we reported that CUDC-101 has potent antiproliferative and proapoptotic activity in cultured tumor cells and in vivo xenograft models. We now show that cancer cells that have acquired resistance to single-target EGFR inhibitors through upregulation of AXL or loss of E-cadherin remain sensitive to CUDC-101, which inhibits MET- and AXL-mediated signaling, restores E-cadherin expression, and reduces cell migration. CUDC-101 also efficiently inhibited the proliferation of MET-overexpressing non-small cell lung cancer and gastric cancer cell lines and inhibited the migration and invasion of invasive tumor cells. Taken together, these results suggest that coupling HDAC and HER2 inhibitory activities to an EGFR inhibitor may potentially be effective in overcoming drug resistance and preventing cancer cell migration. ©2013 AACR

  10. Deacetylase inhibitors dissociate the histone-targeting ING2 subunit from the Sin3 complex

    PubMed Central

    Smith, Karen T.; Martin-Brown, Skylar A.; Florens, Laurence; Washburn, Michael P.; Workman, Jerry L.

    2010-01-01

    Summary Histone deacetylase (HDAC) inhibitors are in clinical development for several diseases, including cancers and neurodegenerative disorders. HDACs1 and 2 are among the targets of these inhibitors and are part of multisubunit protein complexes. HDAC inhibitors (HDACi) block the activity of HDACs by chelating a zinc molecule in their catalytic sites. It is not known if the inhibitors have any additional functional effects on the multisubunit HDAC complexes. Here, we find that suberoylanilide hydroxamic acid (SAHA), the recently FDA approved HDACi, causes the dissociation of the PHD-finger containing ING2 subunit from the Sin3 deacetylase complex. Loss of ING2 disrupts the in vivo binding of the Sin3 complex to the p21 promoter, an important target gene for cell growth inhibition by SAHA. Our findings reveal a new molecular mechanism by which HDAC inhibitors disrupt deacetylase function. PMID:20142042

  11. Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, protects dopaminergic neurons from neurotoxin-induced damage

    PubMed Central

    Chen, SH; Wu, HM; Ossola, B; Schendzielorz, N; Wilson, BC; Chu, CH; Chen, SL; Wang, Q; Zhang, D; Qian, L; Li, X; Hong, JS; Lu, RB

    2012-01-01

    BACKGROUND AND PURPOSE Prevention or disease-modifying therapies are critical for the treatment of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. However, no such intervention is currently available. Growing evidence has demonstrated that administration of histone deacetylase (HDAC) inhibitors ameliorates a wide range of neurologic and psychiatric disorders in experimental models. Suberoylanilide hydroxamic acid (SAHA) was the first HDAC inhibitor approved by the Food and Drug Administration for the sole use of cancer therapy. The purpose of this study was to explore the potential new indications of SAHA for therapy of neurodegenerative diseases in in vitro Parkinson's disease models. EXPERIMENTAL APPROACH Mesencephalic neuron–glia cultures and reconstituted cultures were used to investigate neurotrophic and neuroprotective effects of SAHA. We measured toxicity in dopaminergic neurons, using dopamine uptake assay and morphological analysis and expression of neurotrophic substances by enzyme-linked immunosorbent assay and real-time RT PCR. KEY RESULTS In mesencephalic neuron–glia cultures, SAHA displayed dose- and time-dependent prolongation of the survival and protection against neurotoxin-induced neuronal death of dopaminergic neurons. Mechanistic studies revealed that the neuroprotective effects of SAHA were mediated in part by promoting release of neurotrophic factors from astroglia through inhibition of histone deacetylation. CONCLUSION AND IMPLICATIONS The novel neurotrophic and neuroprotective effects of SAHA demonstrated in this study suggest that further study of this HDAC inhibitor could provide a new therapeutic approach to the treatment of neurodegenerative diseases. PMID:21726209

  12. Novel insights into appropriate encapsulation methods for bioactive compounds into polymers: a study with peptides and HDAC inhibitors.

    PubMed

    Hennig, Dorle; Schubert, Stephanie; Dargatz, Harald; Kostenis, Evi; Fahr, Alfred; Schubert, Ulrich S; Heinzel, Thorsten; Imhof, Diana

    2014-01-01

    The use of different nanoparticles (NPs) for successful encapsulation of bioactive substances is discussed. The inclusion efficiency into liposomes, acetalated dextran (Ac-Dex), and variants of poly[(lactic acid)-co-(glycolic acid)] (PLGA) NPs is analyzed after chemical degradation. Efficient inclusion of SIRT1 inhibitor Ex527 in liposomes, Ac-Dex- and PLGA-NPs is observed for all procedures used. Activity of Ex527 is demonstrated by monitoring the acetylation status of SIRT1-target p53. In contrast, small peptides are only incorporated into acid-terminated PLGA-NPs and marginally into Ac-Dex-NPs. The yield depends on peptide sequence and terminal modifications. Activity is exemplified for angiotensin II using the dynamic mass redistribution technology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Molecular mechanism of transcriptional repression of AhR repressor involving ANKRA2, HDAC4, and HDAC5

    SciTech Connect

    Oshima, Motohiko; Mimura, Junsei; Yamamoto, Masayuki; Fujii-Kuriyama, Yoshiaki

    2007-12-14

    The Aryl hydrocarbon receptor repressor (AhRR) has been proposed to inhibit Aryl hydrocarbon receptor (AhR) activity by competing with AhR for forming a heterodimer with AhR nuclear translocator (Arnt) and subsequently binding to the xenobiotic responsive elements (XRE). However, the precise mechanism of AhRR inhibitory activity remains unknown. Analysis of the inhibitory activity of AhRR on the expression of a TK promoter-driven reporter has localized a core repressor domain in the sequence of amino acid residue 555-701. The inhibitory activity of AhRR is sensitive to a histone deacetylase (HDAC) inhibitor, trichostatin A. By using the yeast two-hybrid screening method with the C-terminal sequence of AhRR as bait, we identified a binding partner, Ankyrin-repeat protein2 (ANKRA2), a protein known to interact with HDAC4 and HDAC5. RNA interference experiments using ANKRA2 and AhRR siRNAs indicate that ANKRA2 is important for transcriptional repression by AhRR. We have found that under normal conditions, CYP1A1 gene is kept silent in MEF cells by AhRR/Arnt heterodimer, which binds to the XRE sequence in its promoter and recruits ANKRA2, HDAC4, and HDAC5 as co-repressors.

  14. Phosphorylation of cofilin-1 by ERK confers HDAC inhibitor resistance in hepatocellular carcinoma cells via decreased ROS-mediated mitochondria injury.

    PubMed

    Liao, P-H; Hsu, H-H; Chen, T-S; Chen, M-C; Day, C-H; Tu, C-C; Lin, Y-M; Tsai, F-J; Kuo, W-W; Huang, C-Y

    2017-04-06

    Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Despite the availability of several treatment strategies, resistance to chemotherapeutic agents, which limits the effectiveness of anticancer drugs, is a major problem in cancer therapy. In this study, we used a histone deacetylases inhibitor (HDACi) to establish drug-resistant HCC cells and further analyzed the molecular mechanisms underlying the development of resistance in HCC cells. Compared with the parental cells, HDACi-resistant cells showed high metastatic and pro-survival abilities. Two-dimensional electrophoresis data showed that the cofilin-1 (CFL-1) protein was altered in HDACi-resistant cells and was highly expressed in resistant cells compared with parental cells. The molecular function of CFL-1 is actin depolymerization, and it is involved in tumor metastasis. In this study, we showed that CFL-1 inhibition decreased cell migration and increased cell apoptosis in HDACi-resistant cells. We observed that HDACi induced ROS accumulation in cells and apoptosis via promotion of the CFL-1 interaction with Bax and CFL-1 translocation to the mitochondria, resulting in cytochrome C release. Importantly, phosphorylation of CFL-1 by activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) confers strong protection against HDAC inhibitor-induced cell injury. p-CFL-1 shows a loss of affinity with Bax and will not translocate to mitochondria, stably remaining in the cytoplasm. These results indicate that phosphorylation to inactivate CFL-1 decreased the chemosensitivity to HDAC inhibitors and resulting in drug resistance of HCC cells.

  15. Butyrate, an HDAC inhibitor, stimulates interplay between different posttranslational modifications of histone H3 and differently alters G1-specific cell cycle proteins in vascular smooth muscle cells.

    PubMed

    Mathew, Omana P; Ranganna, Kasturi; Yatsu, Frank M

    2010-12-01

    HDACs and HATs regulate histone acetylation, an epigenetic modification that controls chromatin structure and through it, gene expression. Butyrate, a dietary HDAC inhibitor, inhibits VSMC proliferation, a crucial factor in atherogenesis, and the principle mechanism in arterial and in-stent restenosis. Here, the link between antiproliferation action of butyrate and the portraits of global covalent modifications of histone H3 that it induces are characterized to understand the mechanics of butyrate-arrested VSMC proliferation. Analysis of histone H3 modifications specific to butyrate arrested VSMC proliferation display induction of histone H3-Lysine9 acetylation, inhibition of histone H3-Serine10 phosphorylation, reduction of histone H3-Lysine9 dimethylation and stimulation of histone H3-Lysine4 di-methylation, which is linked to transcriptional activation, cell cycle/mitosis, transcriptional suppression and activation, respectively. Conversely, untreated VSMCs exhibit inhibition of H3-Lysine9 acetylation, induction of H3-Serine10 phosphorylation, stimulation of H3-Lysine9 di-methylation and reduction in H3-Lysine4 di-methylation. Butyrate's cooperative effects on H3-Lysine9 acetylation and H3-Serine10 phosphorylation, and contrasting effects on di-methylation of H3-Lysine9 and H3-Lysine4 suggests that the interplay between these site-specific modifications cause distinct chromatin alterations that allow cyclin D1 and D3 induction, G1-specific cdk4, cdk6 and cdk2 downregulation, and upregulation of cdk inhibitors, p15INK4b and p21Cip1. Regardless of butyrate's effect on D-type cyclins, downregulation of G1-specific cdks and upregulation of cdk inhibitors by butyrate prevents cell cycle progression by failing to inactivate Rb. Overall, through chromatin remodeling, butyrate appears to differentially alter G1-specific cell cycle proteins to ensure proliferation arrest of VSMCs, a crucial cellular component of blood vessel wall.

  16. The HDAC inhibitor AR42 interacts with pazopanib to kill trametinib/dabrafenib-resistant melanoma cells in vitro and in vivo

    PubMed Central

    Booth, Laurence; Roberts, Jane L.; Sander, Cindy; Lee, John; Kirkwood, John M.; Poklepovic, Andrew; Dent, Paul

    2017-01-01

    Studies focused on the killing of activated B-RAF melanoma cells by the histone deacetylase (HDAC) inhibitor AR42. Compared to other tumor cell lines, PDX melanoma isolates were significantly more sensitive to AR42-induced killing. AR42 and the multi-kinase inhibitor pazopanib interacted to activate: an eIF2α–Beclin1 pathway causing autophagosome formation; an eIF2α–DR4/DR5/CD95 pathway; and an eIF2α-dependent reduction in the expression of c-FLIP-s, MCL-1 and BCL-XL. AR42 did not alter basal chaperone activity but increased the ability of pazopanib to inhibit HSP90, HSP70 and GRP78. AR42 and pazopanib caused HSP90/HSP70 dissociation from RAF-1 and B-RAF that resulted in reduced ‘RAF’ expression. The drug combination activated a DNA-damage-ATM-AMPK pathway that was associated with: NFκB activation; reduced mTOR S2448 and ULK-1 S757 phosphorylation; and increased ULK-1 S317 and ATG13 S318 phosphorylation. Knock down of PERK, eIF2α, Beclin1, ATG5 or AMPKα, or expression of IκB S32A S36A, ca-mTOR or TRX, reduced cell killing. AR42, via lysosomal degradation, reduced the protein expression of HDACs 2/5/6/10/11. In vivo, a 3-day exposure of dabrafenib/trametinib resistant melanoma cells to the AR42 pazopanib combination reduced tumor growth and enhanced survival from ∼25 to ∼40 days. Tumor cells that had adapted through therapy exhibited elevated HGF expression and the c-MET inhibitor crizotinib enhanced AR42 pazopanib lethality in this evolved drug-resistant population. PMID:28146421

  17. HDAC1 and HDAC2 independently predict mortality in hepatocellular carcinoma by a competing risk regression model in a Southeast Asian population

    PubMed Central

    LER, SER YENG; LEUNG, CAROL HO WING; KHIN, LAY WAI; LU, GUO-DONG; SALTO-TELLEZ, MANUEL; HARTMAN, MIKAEL; IAU, PHILIP TSAU CHOONG; YAP, CELESTIAL T.; HOOI, SHING CHUAN

    2015-01-01

    Histone deacetylases (HDACs) are enzymes involved in transcriptional repression. We aimed to examine the significance of HDAC1 and HDAC2 gene expression in the prediction of recurrence and survival in 156 patients with hepatocellular carcinoma (HCC) among a South East Asian population who underwent curative surgical resection in Singapore. We found that HDAC1 and HDAC2 were upregulated in the majority of HCC tissues. The presence of HDAC1 in tumor tissues was correlated with poor tumor differentiation. Notably, HDAC1 expression in adjacent non-tumor hepatic tissues was correlated with the presence of satellite nodules and multiple lesions, suggesting that HDAC1 upregulation within the field of HCC may contribute to tumor spread. Using competing risk regression analysis, we found that increased cancer-specific mortality was significantly associated with HDAC2 expression. Mortality was also increased with high HDAC1 expression. In the liver cancer cell lines, HEP3B, HEPG2, PLC5, and a colorectal cancer cell line, HCT116, the combined knockdown of HDAC1 and HDAC2 increased cell death and reduced cell proliferation as well as colony formation. In contrast, knockdown of either HDAC1 or HDAC2 alone had minimal effects on cell death and proliferation. Taken together, our study suggests that both HDAC1 and HDAC2 exert pro-survival effects in HCC cells, and the combination of isoform-specific HDAC inhibitors against both HDACs may be effective in targeting HCC to reduce mortality. PMID:26352599

  18. Mechanistic Insights into the Binding of Class IIa HDAC Inhibitors toward Spinocerebellar Ataxia Type-2: A 3D-QSAR and Pharmacophore Modeling Approach.

    PubMed

    Sinha, Siddharth; Goyal, Sukriti; Somvanshi, Pallavi; Grover, Abhinav

    2016-01-01

    Spinocerebellar ataxia (SCA-2) type-2 is a rare neurological disorder among the nine polyglutamine disorders, mainly caused by polyQ (CAG) trinucleotide repeats expansion within gene coding ataxin-2 protein. The expanded trinucleotide repeats within the ataxin-2 protein sequesters transcriptional cofactors i.e., CREB-binding protein (CBP), Ataxin-2 binding protein 1 (A2BP1) leading to a state of hypo-acetylation and transcriptional repression. Histone de-acetylases inhibitors (HDACi) have been reported to restore transcriptional balance through inhibition of class IIa HDAC's, that leads to an increased acetylation and transcription as demonstrated through in-vivo studies on mouse models of Huntington's. In this study, 61 di-aryl cyclo-propanehydroxamic acid derivatives were used for developing three dimensional (3D) QSAR and pharmacophore models. These models were then employed for screening and selection of anti-ataxia compounds. The chosen QSAR model was observed to be statistically robust with correlation coefficient (r(2)) value of 0.6774, cross-validated correlation coefficient (q(2)) of 0.6157 and co-relation coefficient for external test set (pred_r(2)) of 0.7570. A high F-test value of 77.7093 signified the robustness of the model. Two potential drug leads ZINC 00608101 (SEI) and ZINC 00329110 (ACI) were selected after a coalesce procedure of pharmacophore based screening using the pharmacophore model ADDRR.20 and structural analysis using molecular docking and dynamics simulations. The pharmacophore and the 3D-QSAR model generated were further validated for their screening and prediction ability using the enrichment factor (EF), goodness of hit (GH), and receiver operating characteristics (ROC) curve analysis. The compounds SEI and ACI exhibited a docking score of -10.097 and -9.182 kcal/mol, respectively. An evaluation of binding conformation of ligand-bound protein complexes was performed with MD simulations for a time period of 30 ns along with free

  19. HDAC Inhibitors Upregulate B Cell microRNAs that Silence AID and Blimp-1 Expression for Epigenetic Modulation of Antibody and Autoantibody Responses

    PubMed Central

    White, Clayton A; Pone, Egest J; Lam, Tonika; Tat, Connie; Hayama, Ken L; Li, Guideng; Zan, Hong; Casali, Paolo

    2014-01-01

    Class-switch DNA recombination (CSR) and somatic hypermutation (SHM), which require AID, and plasma cell differentiation, which requires Blimp-1, are critical for the generation of class-switched and hypermutated (mature) antibody and autoantibody responses. We showed here that the histone deacetylase (HDAC) inhibitors (HDI) valproic acid (VPA) and butyrate upregulated miR-155, miR-181b and miR-361, which silenced AICDA/Aicda (AID) mRNA, and miR-23b, miR-30a and miR-125b, which silenced PRDM1/Prdm1 (Blimp-1) mRNA, in human and mouse B cells. This led to downregulation of AID, Blimp-1 and Xbp-1 expression, thereby dampening CSR, SHM and plasma cell differentiation without altering B cell viability or proliferation. The selectivity of HDI-mediated silencing of AICDA/Aicda and PRDM1/Prdm1 was emphasized by unchanged expression of HoxC4 and Irf4 (important inducers/modulators of AICDA/Aicda), Rev1 and Ung (central elements for CSR/SHM), and Bcl6, Bach2 or Pax5 (repressors of PRDM1/Prdm1 expression), as well as unchanged expression of miR-19a/b, miR-20a and miR-25, which are not known to regulate AICDA/Aicda or PRDM1/Prdm1. Through these B cell intrinsic epigenetic mechanisms, VPA blunted class-switched and hypermutated T-dependent and T-independent antibody responses in C57BL/6 mice. In addition, it decreased class-switched and hypermutated autoantibodies, ameliorated disease and extended survival in lupus MRL/Faslpr/lpr mice. Our findings outline epigenetic mechanisms that modulate expression of an enzyme (AID) and transcription factors (Blimp-1 and Xbp-1) that critical to the B cell differentiation processes that underpin antibody and autoantibody responses. They also provide therapeutics proof-of-principle in autoantibody-mediated autoimmunity. PMID:25392531

  20. Mechanistic Insights into the Binding of Class IIa HDAC Inhibitors toward Spinocerebellar Ataxia Type-2: A 3D-QSAR and Pharmacophore Modeling Approach

    PubMed Central

    Sinha, Siddharth; Goyal, Sukriti; Somvanshi, Pallavi; Grover, Abhinav

    2017-01-01

    Spinocerebellar ataxia (SCA-2) type-2 is a rare neurological disorder among the nine polyglutamine disorders, mainly caused by polyQ (CAG) trinucleotide repeats expansion within gene coding ataxin-2 protein. The expanded trinucleotide repeats within the ataxin-2 protein sequesters transcriptional cofactors i.e., CREB-binding protein (CBP), Ataxin-2 binding protein 1 (A2BP1) leading to a state of hypo-acetylation and transcriptional repression. Histone de-acetylases inhibitors (HDACi) have been reported to restore transcriptional balance through inhibition of class IIa HDAC's, that leads to an increased acetylation and transcription as demonstrated through in-vivo studies on mouse models of Huntington's. In this study, 61 di-aryl cyclo-propanehydroxamic acid derivatives were used for developing three dimensional (3D) QSAR and pharmacophore models. These models were then employed for screening and selection of anti-ataxia compounds. The chosen QSAR model was observed to be statistically robust with correlation coefficient (r2) value of 0.6774, cross-validated correlation coefficient (q2) of 0.6157 and co-relation coefficient for external test set (pred_r2) of 0.7570. A high F-test value of 77.7093 signified the robustness of the model. Two potential drug leads ZINC 00608101 (SEI) and ZINC 00329110 (ACI) were selected after a coalesce procedure of pharmacophore based screening using the pharmacophore model ADDRR.20 and structural analysis using molecular docking and dynamics simulations. The pharmacophore and the 3D-QSAR model generated were further validated for their screening and prediction ability using the enrichment factor (EF), goodness of hit (GH), and receiver operating characteristics (ROC) curve analysis. The compounds SEI and ACI exhibited a docking score of −10.097 and −9.182 kcal/mol, respectively. An evaluation of binding conformation of ligand-bound protein complexes was performed with MD simulations for a time period of 30 ns along with free

  1. Effect of histone deacetylase inhibitors trichostatin A and valproic acid on hair cell regeneration in zebrafish lateral line neuromasts

    PubMed Central

    He, Yingzi; Cai, Chengfu; Tang, Dongmei; Sun, Shan; Li, Huawei

    2014-01-01

    In humans, auditory hair cells are not replaced when injured. Thus, cochlear hair cell loss causes progressive and permanent hearing loss. Conversely, non-mammalian vertebrates are capable of regenerating lost sensory hair cells. The zebrafish lateral line has numerous qualities that make it well-suited for studying hair cell development and regeneration. Histone deacetylase (HDAC) activity has been shown to have an important role in regenerative processes in vertebrates, but its function in hair cell regeneration in vivo is not fully understood. Here, we have examined the role of HDAC activity in hair cell regeneration in the zebrafish lateral line. We eliminated lateral line hair cells of 5-day post-fertilization larvae using neomycin and then treated the larvae with HDAC inhibitors. To assess hair cell regeneration, we used 5-bromo-2-deoxyuridine (BrdU) incorporation in zebrafish larvae to label mitotic cells after hair cell loss. We found that pharmacological inhibition of HDACs using trichostatin A (TSA) or valproic acid (VPA) increased histone acetylation in the regenerated neuromasts following neomycin-induced damage. We also showed that treatment with TSA or VPA decreased the number of supporting cells and regenerated hair cells in response to hair cell damage. Additionally, BrdU immunostaining and western blot analysis showed that TSA or VPA treatment caused a significant decrease in the percentage of S-phase cells and induced p21Cip1 and p27Kip1 expression, both of which are likely to explain the decrease in the amount of newly regenerated hair cells in treated embryos. Finally, we showed that HDAC inhibitors induced no observable cell death in neuromasts as measured by cleaved caspase-3 immunohistochemistry and western blot analysis. Taken together, our results demonstrate that HDAC activity has an important role in the regeneration of hair cells in the lateral line. PMID:25431550

  2. Type-specific roles of histone deacetylase (HDAC) overexpression in ovarian carcinoma: HDAC1 enhances cell proliferation and HDAC3 stimulates cell migration with downregulation of E-cadherin.

    PubMed

    Hayashi, Akiko; Horiuchi, Akiko; Kikuchi, Norihiko; Hayashi, Takuma; Fuseya, Chiho; Suzuki, Akihisa; Konishi, Ikuo; Shiozawa, Tanri

    2010-09-01

    Histone acetylation/deacetylation controls chromatin activity and subsequent gene transcription. Recent studies demonstrated the activation of histone deacetylases (HDACs) in various human malignancies; however, the expression and function of HDACs in ovarian tumors are not fully understood. In this study, we examined the immunohistochemical expression of HDAC1, HDAC2 and HDAC3 using tissues obtained from 115 cases of ovarian tumors and compared it with that of Ki-67 (a growth marker), p21, and E-cadherin and clinicopathological parameters. In addition, we analyzed the effect of specific siRNA for HDAC1, HDAC2 and HDAC3 on the expression of cell cycle-related molecules and E-cadherin to clarify the functional difference among the 3 HDACs. The results indicated that the immunohistochemical expression of nuclear HDAC1, HDAC2 and HDAC3 proteins increased stepwise in benign, borderline and malignant tumors. The expression of HDAC1 and HDAC2 was correlated with Ki-67 expression and that of HDAC3 was inversely correlated with E-cadherin expression. Among the HDACs examined, only HDAC1 was associated with a poor outcome, when overexpressed. Treatment with HDAC inhibitors suppressed the proliferation of ovarian cancer cells in association with apoptosis. A specific siRNA for HDAC1 significantly reduced the proliferation of ovarian carcinoma cells via downregulation of cyclin A expression, but siRNA for HDAC3 reduced the cell migration with elevated E-cadherin expression. Our results suggested that HDAC1 plays an important role in the proliferation of ovarian cancer cells, whereas HDAC3 functions in cell adhesion and migration. Therefore, specific therapeutic approaches should be considered according to the HDAC subtypes.

  3. Complex structure of a bacterial class 2 histone deacetylase homologue with a trifluoromethylketone inhibitor

    SciTech Connect

    Nielsen, Tine Kragh; Hildmann, Christian; Riester, Daniel; Wegener, Dennis; Schwienhorst, Andreas; Ficner, Ralf

    2007-04-01

    The crystal structure of HDAH FB188 in complex with a trifluoromethylketone at 2.2 Å resolution is reported and compared to a previously determined inhibitor complex. Histone deacetylases (HDACs) have emerged as attractive targets in anticancer drug development. To date, a number of HDAC inhibitors have been developed and most of them are hydroxamic acid derivatives, typified by suberoylanilide hydroxamic acid (SAHA). Not surprisingly, structural information that can greatly enhance the design of novel HDAC inhibitors is so far only available for hydroxamic acids in complex with HDAC or HDAC-like enzymes. Here, the first structure of an enzyme complex with a nonhydroxamate HDAC inhibitor is presented. The structure of the trifluoromethyl ketone inhibitor 9,9,9-trifluoro-8-oxo-N-phenylnonanamide in complex with bacterial FB188 HDAH (histone deacetylase-like amidohydrolase from Bordetella/Alcaligenes strain FB188) has been determined. HDAH reveals high sequential and functional homology to human class 2 HDACs and a high structural homology to human class 1 HDACs. Comparison with the structure of HDAH in complex with SAHA reveals that the two inhibitors superimpose well. However, significant differences in binding to the active site of HDAH were observed. In the presented structure the O atom of the trifluoromethyl ketone moiety is within binding distance of the Zn atom of the enzyme and the F atoms participate in interactions with the enzyme, thereby involving more amino acids in enzyme–inhibitor binding.

  4. Cell type-specific anti-cancer properties of valproic acid: independent effects on HDAC activity and Erk1/2 phosphorylation

    PubMed Central

    2010-01-01

    Background The anti-epileptic drug valproic acid (VPA) has attracted attention as an anti-cancer agent. Methods The present study investigated effects of VPA exposure on histone deacetylase (HDAC) inhibition, cell growth, cell speed, and the degree of Erk1/2 phosphorylation in 10 cell lines (BT4C, BT4Cn, U87MG, N2a, PC12-E2, CSML0, CSML100, HeLa, L929, Swiss 3T3). Results VPA induced significant histone deacetylase (HDAC) inhibition in most of the cell lines, but the degree of inhibition was highly cell type-specific. Moreover, cell growth, motility and the degree of Erk1/2 phosphorylation were inhibited, activated, or unaffected by VPA in a cell type-specific manner. Importantly, no relationship was found between the effects of VPA on HDAC inhibition and changes in the degree of Erk1/2 phosphorylation, cell growth, or motility. In contrast, VPA-induced modulation of the MAPK pathway downstream of Ras but upstream of MEK (i.e., at the level of Raf) was important for changes in cell speed. Conclusions These results suggest that VPA can modulate the degree of Erk1/2 phosphorylation in a manner unrelated to HDAC inhibition and emphasize that changes in the degree of Erk1/2 phosphorylation are also important for the anti-cancer properties of VPA. PMID:20663132

  5. Histone deacetylases (HDACs): characterization of the classical HDAC family.

    PubMed Central

    de Ruijter, Annemieke J M; van Gennip, Albert H; Caron, Huib N; Kemp, Stephan; van Kuilenburg, André B P

    2003-01-01

    Transcriptional regulation in eukaryotes occurs within a chromatin setting, and is strongly influenced by the post-translational modification of histones, the building blocks of chromatin, such as methylation, phosphorylation and acetylation. Acetylation is probably the best understood of these modifications: hyperacetylation leads to an increase in the expression of particular genes, and hypoacetylation has the opposite effect. Many studies have identified several large, multisubunit enzyme complexes that are responsible for the targeted deacetylation of histones. The aim of this review is to give a comprehensive overview of the structure, function and tissue distribution of members of the classical histone deacetylase (HDAC) family, in order to gain insight into the regulation of gene expression through HDAC activity. SAGE (serial analysis of gene expression) data show that HDACs are generally expressed in almost all tissues investigated. Surprisingly, no major differences were observed between the expression pattern in normal and malignant tissues. However, significant variation in HDAC expression was observed within tissue types. HDAC inhibitors have been shown to induce specific changes in gene expression and to influence a variety of other processes, including growth arrest, differentiation, cytotoxicity and induction of apoptosis. This challenging field has generated many fascinating results which will ultimately lead to a better understanding of the mechanism of gene transcription as a whole. PMID:12429021

  6. The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Alleviates Salinity Stress in Cassava

    PubMed Central

    Patanun, Onsaya; Ueda, Minoru; Itouga, Misao; Kato, Yukari; Utsumi, Yoshinori; Matsui, Akihiro; Tanaka, Maho; Utsumi, Chikako; Sakakibara, Hitoshi; Yoshida, Minoru; Narangajavana, Jarunya; Seki, Motoaki

    2017-01-01

    Cassava (Manihot esculenta Crantz) demand has been rising because of its various applications. High salinity stress is a major environmental factor that interferes with normal plant growth and limits crop productivity. As well as genetic engineering to enhance stress tolerance, the use of small molecules is considered as an alternative methodology to modify plants with desired traits. The effectiveness of histone deacetylase (HDAC) inhibitors for increasing tolerance to salinity stress has recently been reported. Here we use the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), to enhance tolerance to high salinity in cassava. Immunoblotting analysis reveals that SAHA treatment induces strong hyper-acetylation of histones H3 and H4 in roots, suggesting that SAHA functions as the HDAC inhibitor in cassava. Consistent with increased tolerance to salt stress under SAHA treatment, reduced Na+ content and increased K+/Na+ ratio were detected in SAHA-treated plants. Transcriptome analysis to discover mechanisms underlying salinity stress tolerance mediated through SAHA treatment reveals that SAHA enhances the expression of 421 genes in roots under normal condition, and 745 genes at 2 h and 268 genes at 24 h under both SAHA and NaCl treatment. The mRNA expression of genes, involved in phytohormone [abscisic acid (ABA), jasmonic acid (JA), ethylene, and gibberellin] biosynthesis pathways, is up-regulated after high salinity treatment in SAHA-pretreated roots. Among them, an allene oxide cyclase (MeAOC4) involved in a crucial step of JA biosynthesis is strongly up-regulated by SAHA treatment under salinity stress conditions, implying that JA pathway might contribute to increasing salinity tolerance by SAHA treatment. Our results suggest that epigenetic manipulation might enhance tolerance to high salinity stress in cassava. PMID:28119717

  7. The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Alleviates Salinity Stress in Cassava.

    PubMed

    Patanun, Onsaya; Ueda, Minoru; Itouga, Misao; Kato, Yukari; Utsumi, Yoshinori; Matsui, Akihiro; Tanaka, Maho; Utsumi, Chikako; Sakakibara, Hitoshi; Yoshida, Minoru; Narangajavana, Jarunya; Seki, Motoaki

    2016-01-01

    Cassava (Manihot esculenta Crantz) demand has been rising because of its various applications. High salinity stress is a major environmental factor that interferes with normal plant growth and limits crop productivity. As well as genetic engineering to enhance stress tolerance, the use of small molecules is considered as an alternative methodology to modify plants with desired traits. The effectiveness of histone deacetylase (HDAC) inhibitors for increasing tolerance to salinity stress has recently been reported. Here we use the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), to enhance tolerance to high salinity in cassava. Immunoblotting analysis reveals that SAHA treatment induces strong hyper-acetylation of histones H3 and H4 in roots, suggesting that SAHA functions as the HDAC inhibitor in cassava. Consistent with increased tolerance to salt stress under SAHA treatment, reduced Na(+) content and increased K(+)/Na(+) ratio were detected in SAHA-treated plants. Transcriptome analysis to discover mechanisms underlying salinity stress tolerance mediated through SAHA treatment reveals that SAHA enhances the expression of 421 genes in roots under normal condition, and 745 genes at 2 h and 268 genes at 24 h under both SAHA and NaCl treatment. The mRNA expression of genes, involved in phytohormone [abscisic acid (ABA), jasmonic acid (JA), ethylene, and gibberellin] biosynthesis pathways, is up-regulated after high salinity treatment in SAHA-pretreated roots. Among them, an allene oxide cyclase (MeAOC4) involved in a crucial step of JA biosynthesis is strongly up-regulated by SAHA treatment under salinity stress conditions, implying that JA pathway might contribute to increasing salinity tolerance by SAHA treatment. Our results suggest that epigenetic manipulation might enhance tolerance to high salinity stress in cassava.

  8. Expression of non-secreted IL-4 is associated with HDAC inhibitor-induced cell death, histone acetylation and c-Jun regulation in human gamma/delta T-cells

    PubMed Central

    Bhat, Jaydeep; Schütze, Stefan; Zeissig, Sebastian; Ammerpohl, Ole; Adam, Dieter; Kabelitz, Dieter

    2016-01-01

    Previously, the expression of a non-secreted IL-4 variant (IL-4δ13) has been described in association with apoptosis and age-dependent Th2 T-cell polarization. Signaling pathways involved in this process have so far not been studied. Here we report the induction of IL-4δ13 expression in human γδ T-cells upon treatment with a sublethal dose of histone deacetylase (HDACi) inhibitor valproic acid (VPA). Induction of IL-4δ13 was associated with increased cytoplasmic IL-4Rα and decreased IL-4 expression, while mRNA for mature IL-4 was concomitantly down-regulated. Importantly, only the simultaneous combination of apoptosis and necroptosis inhibitors prevented IL-4δ13 expression and completely abrogated VPA-induced global histone H3K9 acetylation mark. Further, our work reveals a novel involvement of transcription factor c-Jun in the signaling network of IL-4, HDAC1, caspase-3 and mixed lineage kinase domain-like protein (MLKL). This study provides novel insights into the effects of epigenetic modulator VPA on human γδ T-cell differentiation. PMID:27556516

  9. The PI3K inhibitor GS-1101 synergistically potentiates HDAC inhibitor-induced proliferation inhibition and apoptosis through the inactivation of PI3K and ERK pathways

    PubMed Central

    Bodo, Juraj; Zhao, Xiaoxian; Sharma, Arishya; Hill, Brian T.; Portell, Craig A.; Lannutti, Brian J.; Almasan, Alexandru; Hsi, Eric D.

    2013-01-01

    Previously, we showed that inhibition of the protein kinase C β (PKCβ)/AKT pathway augments engagement of the histone deacetylase inhibitor (HDI)-induced apoptosis in lymphoma cells. In the present study, we investigated the cytotoxicity and mechanisms of cell death induced by the delta isoform-specific phosphatidylinositide 3-kinase (PI3K) inhibitor, GS-1101, in combination with the HDI, panobinostat (LBH589) and suberoylanilide hydroxamic acid (SAHA). Lymphoma cell lines and primary Non-Hodgkin Lymphoma (NHL) and chronic lymphocytic leukaemia (CLL) cells were simultaneously treated with the HDI, LBH589 and GS-1101. An interaction of the LBH589/GS-1101 combination was formally examined by using various concentrations of LBH589 and GS-1101. Combined treatment resulted in a synergistic inhibition of proliferation and showed synergistic effect on apoptotic induction in all tested cell lines and primary NHL and CLL cells. This study indicates that interference with PI3K signalling dramatically increases HDI-mediated apoptosis in malignant haematopoietic cells, possibly through both AKT-dependent or AKT- independent mechanisms. Moreover, the increase in HDI-related apoptosis observed in PI3K inhibitor-treated cells appears to be related to the disruption of the extracellular signal-regulated kinase (ERK) signalling pathway. This study provides a strong rational for testing the combination of PI3K inhibitors and HDI in the clinic. PMID:23889282

  10. A First-in-Class Small-Molecule that Acts as a Dual Inhibitor of HDAC and PDE5 and that Rescues Hippocampal Synaptic Impairment in Alzheimer's Disease Mice.

    PubMed

    Cuadrado-Tejedor, Mar; Garcia-Barroso, Carolina; Sánchez-Arias, Juan A; Rabal, Obdulia; Pérez-González, Marta; Mederos, Sara; Ugarte, Ana; Franco, Rafael; Segura, Victor; Perea, Gertrudis; Oyarzabal, Julen; Garcia-Osta, Ana

    2017-01-01

    The targeting of two independent but synergistic enzymatic activities, histone deacetylases (HDACs, class I and HDAC6) and phosphodiesterase 5 (PDE5), has recently been validated as a potentially novel therapeutic approach for Alzheimer's disease (AD). Here we report the discovery of a new first-in-class small-molecule (CM-414) that acts as a dual inhibitor of PDE5 and HDACs. We have used this compound as a chemical probe to validate this systems therapeutics strategy, where an increase in the activation of cAMP/cGMP-responsive element-binding protein (CREB) induced by PDE5 inhibition, combined with moderate HDAC class I inhibition, leads to efficient histone acetylation. This molecule rescued the impaired long-term potentiation evident in hippocampal slices from APP/PS1 mice. Chronic treatment of Tg2576 mice with CM-414 diminished brain Aβ and tau phosphorylation (pTau) levels, increased the inactive form of GSK3β, reverted the decrease in dendritic spine density on hippocampal neurons, and reversed their cognitive deficits, at least in part by inducing the expression of genes related to synaptic transmission. Thus, CM-414 may serve as the starting point to discover balanced dual inhibitors with an optimal efficacy and safety profile for clinical testing on AD patients.

  11. HR23b expression is a potential predictive biomarker for HDAC inhibitor treatment in mesenchymal tumours and is associated with response to vorinostat

    PubMed Central

    Angelika Ihle, Michaela; Merkelbach‐Bruse, Sabine; Hartmann, Wolfgang; Bauer, Sebastian; Ratner, Nancy; Sonobe, Hiroshi; Nishio, Jun; Larsson, Olle; Åman, Pierre; Pedeutour, Florence; Taguchi, Takahiro; Wardelmann, Eva; Buettner, Reinhard

    2016-01-01

    Abstract Histone deacetylases (HDAC) are key players in epigenetic regulation of gene expression and HDAC inhibitor (HDACi) treatment seems to be a promising anticancer therapy in many human tumours, including soft tissue sarcomas. HR23b has been shown to be a potential biomarker for sensitivity to HDACi therapy in cutaneous T‐cell lymphoma and hepatocellular carcinoma. We aimed to evaluate HR23b as a candidate biomarker for HDACi response in sarcomas and gastrointestinal stromal tumours (GIST). Therefore, HR23b expression was analysed comprehensively by western blot in sarcoma and GIST cell lines covering all major clinically relevant subtypes. MTT assay and ApoTox‐GloTM Triplex assay were performed after treatment with vorinostat, belinostat, mocetinostat and entinostat. HR23b protein expression was measured under HDACi treatment. Furthermore, HR23b expression levels were immunohistochemically determined in a large set of 523 clinical samples from sarcoma and GIST patients. Western blot analyses showed that sarcomas differ significantly in their expression of HR23b protein. All HDACi were able to regulate proliferation and apoptosis in vitro. Sensitivity to vorinostat correlated significantly with HR23b protein expression. Immunohistochemical prevalence screening in clinical samples of relevant adult‐type tumours revealed that 12.5% of sarcomas (among them malignant peripheral nerve sheath tumours, pleomorphic liposarcomas, leiomyosarcomas, dedifferentiated liposarcomas, synovial sarcomas and angiosarcomas) and 23.2% of GIST show high HR23b expression. Therefore, HDACi have antiproliferative and proapoptotic effects in sarcomas depending on the expression level of HR23b. These findings suggest that HR23b represents a candidate biomarker for HDACi sensitivity in certain sarcoma types and in GIST. PMID:27499916

  12. The Effects of Pharmacological Inhibition of Histone Deacetylase 3 (HDAC3) in Huntington’s Disease Mice

    PubMed Central

    Jia, Haiqun; Wang, Ying; Morris, Charles D.; Jacques, Vincent; Gottesfeld, Joel M.; Rusche, James R.; Thomas, Elizabeth A.

    2016-01-01

    An important epigenetic modification in Huntington’s disease (HD) research is histone acetylation, which is regulated by histone acetyltransferase and histone deacetylase (HDAC) enzymes. HDAC inhibitors have proven effective in HD model systems, and recent work is now focused on functional dissection of the individual HDAC enzymes in these effects. Histone deacetylase 3 (HDAC3), a member of the class I subfamily of HDACs, has previously been implicated in neuronal toxicity and huntingtin-induced cell death. Hence, we tested the effects of RGFP966 ((E)-N-(2-amino-4-fluorophenyl)-3-(1-cinnamyl-1H-pyrazol-4-yl)acrylamide), a benzamide-type HDAC inhibitor that selectively targets HDAC3, in the N171-82Q transgenic mouse model of HD. We found that RGFP966 at doses of 10 and 25 mg/kg improves motor deficits on rotarod and in open field exploration, accompanied by neuroprotective effects on striatal volume. In light of previous studies implicating HDAC3 in immune function, we measured gene expression changes for 84 immune-related genes elicited by RGFP966 using quantitative PCR arrays. RGFP966 treatment did not cause widespread changes in cytokine/chemokine gene expression patterns, but did significantly alter the striatal expression of macrophage migration inhibitory factor (Mif), a hormone immune modulator associated with glial cell activation, in N171-82Q transgenic mice, but not WT mice. Accordingly, RGFP966-treated mice showed decreased glial fibrillary acidic protein (GFAP) immunoreactivity, a marker of astrocyte activation, in the striatum of N171-82Q transgenic mice compared to vehicle-treated mice. These findings suggest that the beneficial actions of HDAC3 inhibition could be related, in part, with lowered Mif levels and its associated downstream effects. PMID:27031333

  13. Effect of HDAC inhibitors on neuroprotection and neurite outgrowth in primary rat cortical neurons following ischemic insult.

    PubMed

    Hasan, Mohammad Rakibul; Kim, Ji-Hye; Kim, Youn Jung; Kwon, Kyoung Ja; Shin, Chan Young; Kim, Hahn Young; Han, Seol-Heui; Choi, Dong-Hee; Lee, Jongmin

    2013-09-01

    Histone deacetylase inhibitors (HDACi)-valproic acid (VPA) and trichostatin A (TSA) promote neurogenesis, neurite outgrowth, synaptic plasticity and neuroprotection. In this study, we investigated whether VPA and TSA promote post-ischemic neuroprotection and neuronal restoration in rat primary cortical neurons. On 6 days in vitro (DIV), cortical neurons were exposed to oxygen-glucose deprivation for 90 min. Cells were returned to normoxic conditions and cultured for 1, 3, or 7 days with or without VPA and TSA. Control cells were cultured in normoxic conditions only. On 7, 9, and 13 DIV, cells were measured neurite outgrowth using the Axiovision program and stained with Tunel staining kit. Microtubule associated protein-2 immunostaining and tunel staining showed significant recovery of neurite outgrowth and post-ischemic neuronal death by VPA or TSA treatment. We also determined levels of acetylated histone H3, PSD95, GAP 43 and synaptophysin. Significant increases in all three synaptic markers and acetylated histone H3 were observed relative to non-treated cells. Post-ischemic HDACi treatment also significantly raised levels of brain derived neurotrophic factor (BDNF) expression and secreted BDNF. Enhanced BDNF expression by HDACi treatment might have been involved in the post-ischemic neuroprotection and neuronal restorative effects. Our findings suggest that both VPA and TSA treatment during reoxygenation after ischemia may help post-ischemic neuroprotection and neuronal regeneration via increased BDNF expression and activation.

  14. Signal therapy of breast cancers by the HDAC inhibitor FK228 that blocks the activation of PAK1 and abrogates the tamoxifen-resistance.

    PubMed

    Hirokawa, Yumiko; Arnold, Melissa; Nakajima, Hidenori; Zalcberg, John; Maruta, Hiroshi

    2005-09-01

    PAK1, a Rac/CDC42-dependent Ser/Thr kinase, is required for both neurofibromatosis (NF) and RAS transformation in vivo. FK228, a histone deacetylase (HDAC) inhibitor, activates a very specific set of genes such as the tumor suppressor WAF1, an inhibitor of cyclin-dependent kinases (CDKs), and suppresses the growth of these tumors. In addition, this drug downregulates cyclin D1, which is upregulated by RAS through PAK1, in breast cancers. In this study, we demonstrate that FK228 at 0.1-1 nM significantly reduces the kinase activity of PAK1 in these cells, without affecting the protein level of PAK1. Interestingly, estrogen receptor (ER) and PAK1 mutually activate each other in breast cancers. Here we provide an evidence suggesting that breast cancers require PAK1 for their estrogen-dependent growth. Moreover, the treatment with FK228 strongly inhibits the estrogen-dependent growth of human breast cancers (both tamoxifen-sensitive and resistant cell lines) in vivo, suggesting that FK228 and other anti-PAK1 drugs would be useful for the treatment of breast cancers which become resistant to currently used estrogen antagonists such as tamoxifen.

  15. Valproic Acid Antagonizes the Capacity of Other Histone Deacetylase Inhibitors To Activate the Epstein-Barr Virus Lytic Cycle▿

    PubMed Central

    Daigle, Derek; Gradoville, Lyn; Tuck, David; Schulz, Vince; Wang'ondu, Ruth; Ye, Jianjiang; Gorres, Kelly; Miller, George

    2011-01-01

    Diverse stimuli reactivate the Epstein-Barr virus (EBV) lytic cycle in Burkitt lymphoma (BL) cells. In HH514-16 BL cells, two histone deacetylase (HDAC) inhibitors, sodium butyrate (NaB) and trichostatin A (TSA), and the DNA methyltransferase inhibitor azacytidine (AzaCdR) promote lytic reactivation. Valproic acid (VPA), which, like NaB, belongs to the short-chain fatty acid class of HDAC inhibitors, fails to induce the EBV lytic cycle in these cells. Nonetheless, VPA behaves as an HDAC inhibitor; it causes hyperacetylation of histone H3 (J. K. Countryman, L. Gradoville, and G. Miller, J. Virol. 82:4706–4719, 2008). Here we show that VPA blocked the induction of EBV early lytic proteins ZEBRA and EA-D in response to NaB, TSA, or AzaCdR. The block in lytic activation occurred prior to the accumulation of BZLF1 transcripts. Reactivation of EBV in Akata cells, in response to anti-IgG, and in Raji cells, in response to tetradecanoyl phorbol acetate (TPA), was also inhibited by VPA. MS-275 and apicidin, representing two additional classes of HDAC inhibitors, and suberoylanilide hydroxamic acid (SAHA) reactivated EBV in HH514-16 cells; this activity was also inhibited by VPA. Although VPA potently blocked the expression of viral lytic-cycle transcripts, it did not generally block the transcription of cellular genes and was not toxic. The levels and kinetics of specific cellular transcripts, such as Stat3, Frmd6, Mad1, Sepp1, c-fos, c-jun, and egr1, which were activated by NaB and TSA, were similar in HH514-16 cells treated with VPA. When combined with NaB or TSA, VPA did not inhibit the activation of these cellular genes. Changes in cellular gene expression in response to VPA, NaB, or TSA were globally similar as assessed by human genome arrays; however, VPA selectively stimulated the expression of some cellular genes, such as MEF2D, YY1, and ZEB1, that could repress the EBV lytic cycle. We describe a novel example of functional antagonism between HDAC inhibitors. PMID

  16. Discovery of a new class of histone deacetylase inhibitors with a novel zinc binding group

    PubMed Central

    Li, Youxuan; Woster, Patrick M.

    2015-01-01

    Small molecules featuring a hydroxamic acid or a benzamide zinc binding group (ZBG) are the most thoroughly studied histone deacetylase (HDAC) inhibitors. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety and potential metabolic toxicity of the aniline portion of benzamide HDAC inhibitors have stimulated research efforts aimed at discovering alternative ZBGs. Here we report the 2-(oxazol-2-yl)phenol moiety as a novel ZBG that can be used to produce compounds that are potent HDAC inhibitors. A series of analogues with this novel ZBG have been synthesized, and these analogues exhibit selective inhibition against HDAC1 as well as the class IIb HDACs (HDAC6 and HDAC10). Compound 10 possesses an IC50 value of 7.5 μM in the MV-4-11 leukemia cell line, and induces a comparable amount of acetylated histone 3 lysine 9 (H3K9) and p21Waf1/CIP1 as 0.5 μM of SAHA. Modeling of compound 10 in the active site of HDAC2 demonstrates that the 2-(oxazol-2-yl)phenol moiety has a zinc-binding pattern similar to benzamide HDAC inhibitors. PMID:26005563

  17. PI3K/mTOR INHIBITION MARKEDLY POTENTIATES HDAC INHIBITOR ACTIVITY IN NHL CELLS THROUGH BIM- and MCL-1-DEPENDENT MECHANISMS IN VITRO AND IN VIVO

    PubMed Central

    Rahmani, Mohamed; Aust, Mandy Mayo; Benson, Elisa C; Wallace, LaShanale; Friedberg, Jonathan; Grant, Steven

    2014-01-01

    Purpose To explore the efficacy and define mechanisms of action of co-administration of the PI3K/mTOR inhibitor BEZ235 and pan-HDAC inhibitor panobinostat in DLBCL cells. Experimental Design Various DLBCL cells were exposed to panobinostat and BEZ235 alone or together after which apoptosis and signaling/survival pathway perturbations were monitored by flow cytometry and Western blot analysis. Genetic strategies defined the functional significance of such changes, and xenograft mouse models were used to assess tumor growth and animal survival. Results Panobinostat and BEZ235 interacted synergistically in ABC-, GC-, and double-hit DLBCL cells, and MCL cells, but not normal CD34+ cells. Synergism was associated with pronounced AKT dephosphorylation, GSK3 dephosphorylation/activation, Mcl-1 downregulation, Bim up-regulation and increased Bcl-2/Bcl-xL binding, diminished Bax/Bak binding to Bcl-2/Bcl-xL/Mcl-1, increased γH2A.X phosphorylation and histone H3/H4 acetylation, and abrogation of p21CIP1 induction. BEZ235/panobinostat lethality was not susceptible to stromal/microenvironmental forms of resistance. Genetic strategies confirmed significant functional roles for AKT inactivation, Mcl-1 down-regulation, Bim up-regulation, and Bax/Bak in synergism. Finally, co-administration of BEZ235 with panobinostat in immunocompromised mice bearing SU-DHL4-derived tumors significantly reduced tumor growth in association with similar signaling changes observed in vitro, and increased animal survival compared to single agents. Conclusions BEZ235/panobinostat exhibits potent anti-DLBCL activity, including in poor-prognosis ABC- and double-hit sub-types, but not in normal CD34+ cells. Synergism is most likely multi-factorial, involving AKT inactivation/GSK3 activation, Bim up-regulation, Mcl-1 down-regulation, enhanced DNA damage, and is operative in vivo. Combined PI3K/mTOR and HDAC inhibition warrants further attention in DLBCL. PMID:25070836

  18. Generation of Tissue-Specific Mouse Models to Analyze HDAC Functions.

    PubMed

    Hagelkruys, Astrid; Moser, Mirjam A; Seiser, Christian

    2017-01-01

    Histone deacetylases (HDACs) play crucial roles during mammalian development and for cellular homeostasis. In addition, these enzymes are promising targets for small molecule inhibitors in the treatment of cancer and neurological diseases. Conditional HDAC knock-out mice are excellent tools for defining the functions of individual HDACs in vivo and for identifying the molecular targets of HDAC inhibitors in disease. Here, we describe the generation of tissue-specific HDAC knock-out mice and delineate a strategy for the generation of conditional HDAC knock-in mice.

  19. Vorinostat, a histone deacetylase (HDAC) inhibitor, promotes cell cycle arrest and re-sensitizes rituximab- and chemo-resistant lymphoma cells to chemotherapy agents.

    PubMed

    Xue, Kai; Gu, Juan J; Zhang, Qunling; Mavis, Cory; Hernandez-Ilizaliturri, Francisco J; Czuczman, Myron S; Guo, Ye

    2016-02-01

    Preclinical models of chemotherapy resistance and clinical observations derived from the prospective multicenter phase III collaborative trial in relapsed aggressive lymphoma (CORAL) study demonstrated that primary refractory/relapsed B cell diffuse large B cell lymphoma has a poor clinical outcome with current available second-line treatments. Preclinically, we found that rituximab resistance is associated with a deregulation on the mitochondrial potential rendering lymphoma cells resistant to chemotherapy-induced apoptotic stimuli. There is a dire need to develop agents capable to execute alternative pathways of cell death in an attempt to overcome chemotherapy resistance. Posttranscriptional histone modification plays an important role in regulating gene transcription and is altered by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs regulate several key cellular functions, including cell proliferation, cell cycle, apoptosis, angiogenesis, migration, antigen presentation, and/or immune regulation. Given their influence in multiple regulatory pathways, HDAC inhibition is an attractive strategy to evaluate its anti-proliferation activity in cancer cells. To this end, we studied the anti-proliferation activity and mechanisms of action of suberoylanilide hydroxamic acid (SAHA, vorinostat) in rituximab-chemotherapy-resistant preclinical models. A panel of rituximab-chemotherapy-sensitive (RSCL) and rituximab-chemotherapy-resistant cell lines (RRCL) and primary tumor cells isolated from relapsed/refractory B cell lymphoma patients were exposed to escalating doses of vorinostat. Changes in mitochondrial potential, ATP synthesis, and cell cycle distribution were determined by Alamar blue reduction, Titer-Glo luminescent assays, and flow cytometric, respectively. Protein lysates were isolated from vorinostat-exposed cells, and changes in members of Bcl-2 family, cell cycle regulatory proteins, and the acetylation status of histone H3 were

  20. Complementary effects of HDAC inhibitor 4-PB on gap junction communication and cellular export mechanisms support restoration of chemosensitivity of PDAC cells

    PubMed Central

    Ammerpohl, O; Trauzold, A; Schniewind, B; Griep, U; Pilarsky, C; Grutzmann, R; Saeger, H-D; Janssen, O; Sipos, B; Kloppel, G; Kalthoff, H

    2006-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease and one of the cancer entities with the lowest life expectancy. Beside surgical therapy, no effective therapeutic options are available yet. Here, we show that 4-phenylbutyrate (4-PB), a known and well-tolerable inhibitor of histone deacetylases (HDAC), induces up to 70% apoptosis in all cell lines tested (Panc 1, T4M-4, COLO 357, BxPc3). In contrast, it leads to cell cycle arrest in only half of the cell lines tested. This drug increases gap junction communication between adjacent T3M-4 cells in a concentration-dependent manner and efficiently inhibits cellular export mechanisms in Panc 1, T4M-4, COLO 357 and BxPc3 cells. Consequently, in combination with gemcitabine 4-PB shows an overadditive effect on induction of apoptosis in BxPc3 and T3M-4 cells (up to 4.5-fold compared to single drug treatment) with accompanied activation of Caspase 8, BH3 interacting domain death agonist (Bid) and poly (ADP-ribose) polymerase family, member 1 (PARP) cleavage. Although the inhibition of the mitogen-activated protein kinase-pathway has no influence on fulminant induction of apoptosis, the inhibition of the JNK-pathway by SP600125 completely abolishes the overadditive effect induced by the combined application of both drugs, firstly reported by this study. PMID:17164759

  1. In vitro and in vivo anti-uveal melanoma activity of JSL-1, a novel HDAC inhibitor.

    PubMed

    Wang, Yun; Liu, Maoxing; Jin, Yanli; Jiang, Sheng; Pan, Jingxuan

    2017-08-01

    Uveal melanoma (UM) is the most common intraocular malignant neoplasm in adults. Despite the availability of enucleation, radiation and chemotherapy, the prognosis of patients with metastasis remains poor. Therefore, novel effective therapies for patients with metastatic UM are urgently needed. In the present study, we demonstrated that JSL-1, a novel HDAC inhibitor, effectively inhibited the proliferation. JSL-1 induced apoptosis with increased expression of proapoptotic BH3-only protein BIM in UM cells. JSL-1 suppressed migration and invasion of UM cells with MMP-2 decreased. Furthermore, JSL-1 blocked the canonical Wnt/β-catenin pathway, impaired self-renewal capacity and decreased percentage of ALDH(+) cells, thereby reflecting elimination of UM cancer stem-like cells (CSCs) which are believed seeds of metastasis. Importantly, JSL-1 potently inhibited the growth of uveal melanoma xenograft in NOD-SCID mice. These results suggested that JSL-1 may be a promising therapeutic agent for UM. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Fibroadipogenic progenitors mediate the ability of HDAC inhibitors to promote regeneration in dystrophic muscles of young, but not old Mdx mice.

    PubMed

    Mozzetta, Chiara; Consalvi, Silvia; Saccone, Valentina; Tierney, Matthew; Diamantini, Adamo; Mitchell, Kathryn J; Marazzi, Giovanna; Borsellino, Giovanna; Battistini, Luca; Sassoon, David; Sacco, Alessandra; Puri, Pier Lorenzo

    2013-04-01

    HDAC inhibitors (HDACi) exert beneficial effects in mdx mice, by promoting endogenous regeneration; however, the cellular determinants of HDACi activity on dystrophic muscles have not been determined. We show that fibroadipogenic progenitors (FAP) influence the regeneration potential of satellite cells during disease progression in mdx mice and mediate HDACi ability to selectively promote regeneration at early stages of disease. FAPs from young mdx mice promote, while FAPs from old mdx mice repress, satellite cell-mediated formation of myotubes. In young mdx mice HDACi inhibited FAP adipogenic potential, while enhancing their ability to promote differentiation of adjacent satellite cells, through upregulation of the soluble factor follistatin. By contrast, FAPs from old mdx mice were resistant to HDACi-mediated inhibition of adipogenesis and constitutively repressed satellite cell-mediated formation of myotubes. We show that transplantation of FAPs from regenerating young muscles restored HDACi ability to increase myofibre size in old mdx mice. These results reveal that FAPs are key cellular determinants of disease progression in mdx mice and mediate a previously unappreciated stage-specific beneficial effect of HDACi in dystrophic muscles.

  3. mTOR and HDAC inhibitors converge on the TXNIP/thioredoxin pathway to cause catastrophic oxidative stress and regression of RAS-driven tumors.

    PubMed

    Malone, Clare F; Emerson, Chloe; Ingraham, Rachel; Barbosa, William; Guerra, Stephanie; Yoon, Haejin; Liu, Lin L; Michor, Franziska; Haigis, Marcia; Macleod, Kay F; Maertens, Ophélia; Cichowski, Karen

    2017-09-29

    While agents that inhibit specific oncogenic kinases have been successful in a subset of cancers, there are currently few treatment options for malignancies that lack a targetable oncogenic driver. Nevertheless, during tumor evolution cancers engage a variety of protective pathways, which may provide alternative actionable dependencies. Here we identify a promising combination therapy that kills NF1-mutant tumors by triggering catastrophic oxidative stress. Specifically, we show that mTOR and HDAC inhibitors kill aggressive nervous system malignancies and shrink tumors in vivo by converging on the TXNIP/thioredoxin anti-oxidant pathway, through cooperative effects on chromatin and transcription. Accordingly, TXNIP triggers cell death by inhibiting thioredoxin and activating Apoptosis Signal-regulating Kinase 1 (ASK1). Moreover, this drug combination also kills NF1-mutant and KRAS-mutant non-small cell lung cancers. Together these studies identify a promising therapeutic combination for several currently untreatable malignancies, and reveal a protective nodal point of convergence between these important epigenetic and oncogenic enzymes. Copyright ©2017, American Association for Cancer Research.

  4. Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin.

    PubMed

    Furumai, R; Komatsu, Y; Nishino, N; Khochbin, S; Yoshida, M; Horinouchi, S

    2001-01-02

    Trichostatin A (TSA) and trapoxin (TPX) are potent inhibitors of histone deacetylases (HDACs). TSA is proposed to block the catalytic reaction by chelating a zinc ion in the active-site pocket through its hydroxamic acid group. On the other hand, the epoxyketone is suggested to be the functional group of TPX capable of alkylating the enzyme. We synthesized a novel TPX analogue containing a hydroxamic acid instead of the epoxyketone. The hybrid compound cyclic hydroxamic acid-containing peptide (CHAP) 1 inhibited HDAC1 at low nanomolar concentrations. The HDAC1 inhibition by CHAP1 was reversible as it was by TSA, in contrast to the irreversible inhibition by TPX. CHAP with an aliphatic chain length of five, which corresponded to that of acetylated lysine, was stronger than those with other lengths. These results suggest that TPX is a substrate mimic and that the replacement of the epoxyketone with the hydroxamic acid converted TPX to an inhibitor chelating the zinc like TSA. Interestingly, HDAC6, but not HDAC1 or HDAC4, was resistant to TPX and CHAP1, whereas TSA inhibited these HDACs to a similar extent. HDAC6 inhibition by TPX at a high concentration was reversible, probably because HDAC6 is not alkylated by TPX. We further synthesized the counterparts of all known naturally occurring cyclic tetrapeptides containing the epoxyketone. HDAC1 was highly sensitive to all these CHAPs much more than HDAC6, indicating that the structure of the cyclic tetrapeptide framework affects the target enzyme specificity. These results suggest that CHAP is a unique lead to develop isoform-specific HDAC inhibitors.

  5. Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin

    PubMed Central

    Furumai, Ryohei; Komatsu, Yasuhiko; Nishino, Norikazu; Khochbin, Saadi; Yoshida, Minoru; Horinouchi, Sueharu

    2001-01-01

    Trichostatin A (TSA) and trapoxin (TPX) are potent inhibitors of histone deacetylases (HDACs). TSA is proposed to block the catalytic reaction by chelating a zinc ion in the active-site pocket through its hydroxamic acid group. On the other hand, the epoxyketone is suggested to be the functional group of TPX capable of alkylating the enzyme. We synthesized a novel TPX analogue containing a hydroxamic acid instead of the epoxyketone. The hybrid compound cyclic hydroxamic acid-containing peptide (CHAP) 1 inhibited HDAC1 at low nanomolar concentrations. The HDAC1 inhibition by CHAP1 was reversible as it was by TSA, in contrast to the irreversible inhibition by TPX. CHAP with an aliphatic chain length of five, which corresponded to that of acetylated lysine, was stronger than those with other lengths. These results suggest that TPX is a substrate mimic and that the replacement of the epoxyketone with the hydroxamic acid converted TPX to an inhibitor chelating the zinc like TSA. Interestingly, HDAC6, but not HDAC1 or HDAC4, was resistant to TPX and CHAP1, whereas TSA inhibited these HDACs to a similar extent. HDAC6 inhibition by TPX at a high concentration was reversible, probably because HDAC6 is not alkylated by TPX. We further synthesized the counterparts of all known naturally occurring cyclic tetrapeptides containing the epoxyketone. HDAC1 was highly sensitive to all these CHAPs much more than HDAC6, indicating that the structure of the cyclic tetrapeptide framework affects the target enzyme specificity. These results suggest that CHAP is a unique lead to develop isoform-specific HDAC inhibitors. PMID:11134513

  6. Rational design, synthesis and preliminary antitumor activity evaluation of a chlorambucil derivative with potent DNA/HDAC dual-targeting inhibitory activity.

    PubMed

    Xie, Rui; Li, Yan; Tang, Pingwah; Yuan, Qipeng

    2017-09-15

    Histone deacetylases (HDACs) play a pivotal role not only in gene expression but also in DNA repair. Herein, we report the successful design, synthesis and evaluation of a chlorambucil derivative named vorambucil with a hydroxamic acid tail as a DNA/HDAC dual-targeting inhibitor. Vorambucil obtained both potent DNA and HDACs inhibitory activities. Molecular docking results supported the initial pharmacophoric hypothesis and rationalized the potent inhibitory activity of vorambucil against HDAC1, HDAC2 and HDAC6. Vorambucil showed potent antiproliferative activity against all the test four cancer cell lines with IC50 values of as low as 3.2-6.2μM and exhibited 5.0-18.3-fold enhanced antiproliferative activity than chlorambucil. Vorambucil also significantly inhibits colony formation of A375 cancer cells. Further investigation showed that vorambucil remarkably induced apoptosis and arrested the cell cycle of A375 cells at G2/M phase. Vorambucil could be a promising candidate and a useful tool to elucidate the role of those DNA/HDAC dual-targeting inhibitors for cancer therapy. Copyright © 2017. Published by Elsevier Ltd.

  7. Histone deacetylase 3 (HDAC3) as a novel therapeutic target in multiple myeloma

    PubMed Central

    Minami, Jiro; Suzuki, Rikio; Mazitschek, Ralph; Gorgun, Gullu; Ghosh, Balaram; Cirstea, Diana; Hu, Yiguo; Mimura, Naoya; Ohguchi, Hiroto; Cottini, Francesca; Jakubikova, Jana; Munshi, Nikhil C.; Haggarty, Stephen J.; Richardson, Paul G.; Hideshima, Teru; Anderson, Kenneth C.

    2014-01-01

    Histone deacetylases (HDACs) represent novel molecular targets for the treatment of various types of cancers, including multiple myeloma (MM). Many HDAC inhibitors have already shown remarkable anti-tumor activities in the preclinical setting; however, their clinical utility is limited due to unfavorable toxicities associated with their broad range HDAC inhibitory effects. Isoform-selective HDAC inhibition may allow for MM cytotoxicity without attendant side effects. In this study, we demonstrated that HDAC3 knockdown and a small molecule HDAC3 inhibitor BG45 trigger significant MM cell growth inhibition via apoptosis, evidenced by caspase and PARP cleavage. Importantly, HDAC3 inhibition downregulates phosphorylation (tyrosine 705 and serine 727) of STAT3. Neither IL-6 nor bone marrow stromal cells overcome this inhibitory effect of HDAC3 inhibition on p-STAT3 and MM cell growth. Moreover, HDAC3 inhibition also triggers hyperacetylation of STAT3, suggesting crosstalk signaling between phosphorylation and acetylation of STAT3. Importantly, inhibition of HDAC3, but not HDAC1 or HDAC2, significantly enhances bortezomib-induced cytotoxicity. Finally, we confirm that BG45 alone and in combination with bortezomib trigger significant tumor growth inhibition in vivo in a murine xenograft model of human MM. Our results indicate that HDAC3 represents a promising therapeutic target, and validate a prototype novel HDAC3 inhibitor BG45 in MM. PMID:23913134

  8. Utilization of Boron Compounds for the Modification of Suberoyl Anilide Hydroxamic Acid as Inhibitor of Histone Deacetylase Class II Homo sapiens

    PubMed Central

    Bakri, Ridla; Parikesit, Arli Aditya; Satriyanto, Cipta Prio; Kerami, Djati; Tambunan, Usman Sumo Friend

    2014-01-01

    Histone deacetylase (HDAC) has a critical function in regulating gene expression. The inhibition of HDAC has developed as an interesting anticancer research area that targets biological processes such as cell cycle, apoptosis, and cell differentiation. In this study, an HDAC inhibitor that is available commercially, suberoyl anilide hydroxamic acid (SAHA), has been modified to improve its efficacy and reduce the side effects of the compound. Hydrophobic cap and zinc-binding group of these compounds were substituted with boron-based compounds, whereas the linker region was substituted with p-aminobenzoic acid. The molecular docking analysis resulted in 8 ligands with ΔGbinding value more negative than the standards, SAHA and trichostatin A (TSA). That ligands were analyzed based on the nature of QSAR, pharmacological properties, and ADME-Tox. It is conducted to obtain a potent inhibitor of HDAC class II Homo sapiens. The screening process result gave one best ligand, Nova2 (513246-99-6), which was then further studied by molecular dynamics simulations. PMID:25214833

  9. HDAC6 inhibition effectively reverses chemotherapy-induced peripheral neuropathy.

    PubMed

    Krukowski, Karen; Ma, Jiacheng; Golonzhka, Olga; Laumet, Geoffroy O; Gutti, Tanuja; van Duzer, John H; Mazitschek, Ralph; Jarpe, Matthew B; Heijnen, Cobi J; Kavelaars, Annemieke

    2017-03-04

    Chemotherapy-induced peripheral neuropathy is one of the most common doselimiting side-effects of cancer treatment. Currently, there is no FDA-approved treatment available. Histone deacetylase 6 (HDAC6) is a microtubule-associated deacetylase whose function includes regulation of á-tubulin-dependent intracellular mitochondrial transport. Here we examined the effect of HDAC6 inhibition on established cisplatin-induced peripheral neuropathy. We used a novel HDAC6 inhibitor ACY-1083, which shows 260-fold selectivity towards HDAC6 versus other HDACs. Our results show that HDAC6 inhibition prevented cisplatin-induced mechanical allodynia, and also completely reversed already existing cisplatin-induced mechanical allodynia, spontaneous pain, and numbness. These findings were confirmed using the established HDAC6 inhibitor ACY-1215 (Ricolinostat), which is currently in clinical trials for cancer treatment. Mechanistically, treatment with the HDAC6 inhibitor increased á-tubulin acetylation in the peripheral nerve. In addition, HDAC6 inhibition restored the cisplatin-induced reduction in mitochondrial bioenergetics and mitochondrial content in the tibial nerve, indicating increased mitochondrial transport. At a later time point, dorsal root ganglion mitochondrial bioenergetics also improved. HDAC6 inhibition restored the loss of intra-epidermal nerve fiber density in cisplatin-treated mice. Our results demonstrate that pharmacological inhibition of HDAC6 completely reverses all the hallmarks of established cisplatin-induced peripheral neuropathy by normalization of mitochondrial function in DRG and nerve, and restoration of intra-epidermal innervation. These results are especially promising because one of the HDAC6 inhibitors tested here is currently in clinical trials as an add-on cancer therapy, highlighting the potential for a fast clinical translation of our findings.

  10. The histone deacetylase inhibitor valproic acid enhances acquisition, extinction, and reconsolidation of conditioned fear.

    PubMed

    Bredy, Timothy W; Barad, Mark

    2008-01-01

    Histone modifications contribute to the epigenetic regulation of gene expression, a process now recognized to be important for the consolidation of long-term memory. Valproic acid (VPA), used for many years as an anticonvulsant and a mood stabilizer, has effects on learning and memory and enhances the extinction of conditioned fear through its function as a histone deacetylase inhibitor (HDAC). Here we report that VPA enhances long-term memory for both acquisition and extinction of cued-fear. Interestingly, VPA enhances extinction, but also enhances renewal of the original conditioned fear when tested in a within-subjects design. This effect appears to be related to a reconsolidation-like process since a single CS reminder in the presence of VPA can enhance long-term memory for the original fear in the context in which fear conditioning takes place. We also show that by modifying the intertrial interval during extinction training, VPA can strengthen reconsolidation of the original fear memory or enhance long-term memory for extinction such that it becomes independent of context. These findings have important implications for the use of HDAC inhibitors as adjuncts to behavior therapy in the treatment of phobia and related anxiety disorders.

  11. Functional-genetic dissection of HDAC dependencies in mouse lymphoid and myeloid malignancies

    PubMed Central

    Matthews, Geoffrey M.; Mehdipour, Parinaz; Cluse, Leonie A.; Falkenberg, Katrina J.; Wang, Eric; Roth, Mareike; Santoro, Fabio; Vidacs, Eva; Stanley, Kym; House, Colin M.; Rusche, James R.; Vakoc, Christopher R.; Zuber, Johannes; Minucci, Saverio

    2015-01-01

    Histone deacetylase (HDAC) inhibitors (HDACis) have demonstrated activity in hematological and solid malignancies. Vorinostat, romidepsin, belinostat, and panobinostat are Food and Drug Administration–approved for hematological malignancies and inhibit class II and/or class I HDACs, including HDAC1, 2, 3, and 6. We combined genetic and pharmacological approaches to investigate whether suppression of individual or multiple Hdacs phenocopied broad-acting HDACis in 3 genetically distinct leukemias and lymphomas. Individual Hdacs were depleted in murine acute myeloid leukemias (MLL-AF9;NrasG12D; PML-RARα acute promyelocytic leukemia [APL] cells) and Eµ-Myc lymphoma in vitro and in vivo. Strikingly, Hdac3-depleted cells were selected against in competitive assays for all 3 tumor types. Decreased proliferation following Hdac3 knockdown was not prevented by BCL-2 overexpression, caspase inhibition, or knockout of Cdkn1a in Eµ-Myc lymphoma, and depletion of Hdac3 in vivo significantly reduced tumor burden. Interestingly, APL cells depleted of Hdac3 demonstrated a more differentiated phenotype. Consistent with these genetic studies, the HDAC3 inhibitor RGFP966 reduced proliferation of Eµ-Myc lymphoma and induced differentiation in APL. Genetic codepletion of Hdac1 with Hdac2 was pro-apoptotic in Eµ-Myc lymphoma in vitro and in vivo and was phenocopied by the HDAC1/2-specific agent RGFP233. This study demonstrates the importance of HDAC3 for the proliferation of leukemia and lymphoma cells, suggesting that HDAC3-selective inhibitors could prove useful for the treatment of hematological malignancies. Moreover, our results demonstrate that codepletion of Hdac1 with Hdac2 mediates a robust pro-apoptotic response. Our integrated genetic and pharmacological approach provides important insights into the individual or combinations of HDACs that could be prioritized for targeting in a range of hematological malignancies. PMID:26447190

  12. Functional-genetic dissection of HDAC dependencies in mouse lymphoid and myeloid malignancies.

    PubMed

    Matthews, Geoffrey M; Mehdipour, Parinaz; Cluse, Leonie A; Falkenberg, Katrina J; Wang, Eric; Roth, Mareike; Santoro, Fabio; Vidacs, Eva; Stanley, Kym; House, Colin M; Rusche, James R; Vakoc, Christopher R; Zuber, Johannes; Minucci, Saverio; Johnstone, Ricky W

    2015-11-19

    Histone deacetylase (HDAC) inhibitors (HDACis) have demonstrated activity in hematological and solid malignancies. Vorinostat, romidepsin, belinostat, and panobinostat are Food and Drug Administration-approved for hematological malignancies and inhibit class II and/or class I HDACs, including HDAC1, 2, 3, and 6. We combined genetic and pharmacological approaches to investigate whether suppression of individual or multiple Hdacs phenocopied broad-acting HDACis in 3 genetically distinct leukemias and lymphomas. Individual Hdacs were depleted in murine acute myeloid leukemias (MLL-AF9;Nras(G12D); PML-RARα acute promyelocytic leukemia [APL] cells) and Eµ-Myc lymphoma in vitro and in vivo. Strikingly, Hdac3-depleted cells were selected against in competitive assays for all 3 tumor types. Decreased proliferation following Hdac3 knockdown was not prevented by BCL-2 overexpression, caspase inhibition, or knockout of Cdkn1a in Eµ-Myc lymphoma, and depletion of Hdac3 in vivo significantly reduced tumor burden. Interestingly, APL cells depleted of Hdac3 demonstrated a more differentiated phenotype. Consistent with these genetic studies, the HDAC3 inhibitor RGFP966 reduced proliferation of Eµ-Myc lymphoma and induced differentiation in APL. Genetic codepletion of Hdac1 with Hdac2 was pro-apoptotic in Eµ-Myc lymphoma in vitro and in vivo and was phenocopied by the HDAC1/2-specific agent RGFP233. This study demonstrates the importance of HDAC3 for the proliferation of leukemia and lymphoma cells, suggesting that HDAC3-selective inhibitors could prove useful for the treatment of hematological malignancies. Moreover, our results demonstrate that codepletion of Hdac1 with Hdac2 mediates a robust pro-apoptotic response. Our integrated genetic and pharmacological approach provides important insights into the individual or combinations of HDACs that could be prioritized for targeting in a range of hematological malignancies.

  13. Epigenetic control of microsomal prostaglandin E synthase-1 by HDAC-mediated recruitment of p300.

    PubMed

    Fork, Christian; Vasconez, Andrea E; Janetzko, Patrick; Angioni, Carlo; Schreiber, Yannick; Ferreirós, Nerea; Geisslinger, Gerd; Leisegang, Matthias S; Steinhilber, Dieter; Brandes, Ralf P

    2017-02-01

    Nonsteroidal anti-inflammatory drugs are the most widely used medicine to treat pain and inflammation, and to inhibit platelet function. Understanding the expression regulation of enzymes of the prostanoid pathway is of great medical relevance. Histone acetylation crucially controls gene expression. We set out to identify the impact of histone deacetylases (HDACs) on the generation of prostanoids and examine the consequences on vascular function. HDAC inhibition (HDACi) with the pan-HDAC inhibitor, vorinostat, attenuated prostaglandin (PG)E2 generation in the murine vasculature and in human vascular smooth muscle cells. In line with this, the expression of the key enzyme for PGE2 synthesis, microsomal PGE synthase-1 (PTGES1), was reduced by HDACi. Accordingly, the relaxation to arachidonic acid was decreased after ex vivo incubation of murine vessels with HDACi. To identify the underlying mechanism, chromatin immunoprecipitation (ChIP) and ChIP-sequencing analysis were performed. These results suggest that HDACs are involved in the recruitment of the transcriptional activator p300 to the PTGES1 gene and that HDACi prevented this effect. In line with the acetyltransferase activity of p300, H3K27 acetylation was reduced after HDACi and resulted in the formation of heterochromatin in the PTGES1 gene. In conclusion, HDAC activity maintains PTGES1 expression by recruiting p300 to its gene.

  14. Effects of DNMT1 and HDAC Inhibitors on Gene-Specific Methylation Reprogramming during Porcine Somatic Cell Nuclear Transfer

    PubMed Central

    Yu, Bo; He, Xiaoyan; Shi, Junsong; Zhou, Rong; Liu, Dewu; Wu, Zhenfang

    2013-01-01

    Somatic cell nuclear transfer (SCNT) in mammalian cloning currently remains inefficient. Incomplete or erroneous epigenetic reprogramming of specialized donor somatic nuclear and resulting aberrant gene expression during development of cloned embryos is commonly believed as the main reason that causes the low efficiency of SCNT. Use of small molecular reprogramming modifiers to assist the somatic nucleus to mimic naturally occurring DNA methylation and chromatin remodeling in nucleus of fertilization-derived zygotes, has been widely attempted to improve cloning efficiency. However, impacts of these small modifiers on gene-specific methylation dynamics and their potential effects on methylation of imprinted gene have rarely been traced. Here, we attempted two relatively novel DNMT1 inhibitor (DNMTi) and histone deacetylase inhibitor (HDACi), scriptaid and RG108, and demonstrated their effects on dynamics of gene-specific DNA methylation and transcription of porcine SCNT embryos. We found that scriptaid and RG108 had synergetic effects on rescuing the disrupted methylation imprint of H19 during SCNT at least partially by repression over-expressed MBD3 in eight-cell cloned embryos. Furthermore, we firstly identified a differential methylation regions (DMRs) at 5′ flanking regions of XIST gene and found that scriptaid alone and its combination with RG108 modify the dynamics of both transcription and DNA methylation levels in cloned embryos, by different manners. Additionally, we found that scriptaid alone and its combination with RG108 can significantly promote the transcription of NANOG in cloned embryos and enhance their pre-implantation developmental capacity. Our results would contribute to uncovering the epigenetic reprogramming mechanisms underlying the effects of assisted small molecules on improvement of mammalian cloning efficiency. PMID:23741375

  15. Epigenetic bivalent marking is permissive to the synergy of HDAC and PARP inhibitors on TXNIP expression in breast cancer cells.

    PubMed

    Baldan, Federica; Mio, Catia; Lavarone, Elisa; Di Loreto, Carla; Puglisi, Fabio; Damante, Giuseppe; Puppin, Cinzia

    2015-05-01

    Studies on stem cell differentiation led to the identification of paused genes, characterized by the contemporary presence of both activator and repressor epigenetic markers (bivalent marking). TXNIP is an oncosuppressor gene the expression of which was reduced in breast cancer. In the present study, we evaluated whether the concept of epigenetic bivalent marking can be applied to TXNIP gene in breast cancer cells. Using chromatin immunoprecipitation (ChIP), three histone modifications were investigated: two associated with transcriptional activation, lysines 9-14 acetylation of H3 histone (H3K9K14ac) and lysine 4 trimethylation of H3 histone (H3K4me3), and one associated with transcriptional silencing, lysine 27 trimethylation of H3 histone (H3K27me3). According to the bivalent marking model, TXNIP gene appears to be paused in MDA157 cells (markers of active and repressed transcription are present), but are definitively silenced in MDA468 cells (presence of only markers of transcription repression). This was proven by evaluating TXNIP mRNA and protein levels after the treatment of cell lines with a histone deacetylase inhibitor (SAHA) and a poly-ADP-ribose polymerases inhibitor (PJ34). In MDA157 cells, SAHA and PJ34 showed a synergistic effect: a large increment was observed in TXNIP mRNA and protein levels. By contrast, in MDA468 cells, synergy between the two compounds was not observed. Therefore, the pausing epigenetic signature was permissive for synergy between SAHA and PJ34 on TXNIP gene expression. The synergy between SAHA and PJ34 on TXNIP expression was associated with variation in cell viability and apoptosis. In MDA157 cells, but not in MDA468 cells, combined treatment of SAHA and PJ34 induced a decrease in cell viability and an increase of apoptosis. Thus, our data support the hypothesis that TXNIP is an effective target for the treatment of breast cancer.

  16. HDAC2 negatively regulates memory formation and synaptic plasticity

    PubMed Central

    Guan, Ji-Song; Haggarty, Stephen J.; Giacometti, Emanuela; Dannenberg, Jan-Hermen; Joseph, Nadine; Gao, Jun; Nieland, Thomas J.F.; Zhou, Ying; Wang, Xinyu; Mazitschek, Ralph; Bradner, James E.; DePinho, Ronald A.; Jaenisch, Rudolf; Tsai, Li-Huei

    2012-01-01

    Chromatin modifications, especially histone-tail acetylation, have been implicated in memory formation. Increased histone-tail acetylation induced by inhibitors of histone deacetylases (HDACis) facilitates learning and memory in wildtype mice as well as in mouse models of neurodegeneration. Harnessing the therapeutic potential of HDACi requires knowledge of the specific HDAC family member(s) linked to cognitive enhancement. Here we show that neuron-specific overexpression of HDAC2, but not HDAC1, reduced dendritic spine density, synapse number, synaptic plasticity, and memory formation. Conversely, HDAC2 deficiency resulted in increased synapse number and memory facilitation, similar to chronic HDACi treatment in mice. Notably, reduced synapse number and learning impairment of HDAC2-overexpressing mice were ameliorated by chronic HDACi treatment. Correspondingly, HDACi treatment failed to further facilitate memory formation in HDAC2-deficient mice. Furthermore, analysis of promoter occupancy revealed association of HDAC2 with the promoters of genes implicated in synaptic plasticity and memory formation. Together, our results suggest that HDAC2 plays a role in modulating synaptic plasticity and long-lasting changes of neural circuits, which in turn negatively regulates learning and memory. These observations encourage the development and testing of HDAC2-selective inhibitors for human diseases associated with memory impairment. PMID:19424149

  17. HDAC Inhibitor Panobinostat Engages Host Innate Immune Defenses to Promote the Tumoricidal Effects of Trastuzumab in HER2(+) Tumors.

    PubMed

    Medon, Mikolaj; Vidacs, Eva; Vervoort, Stephin J; Li, Jason; Jenkins, Misty R; Ramsbottom, Kelly M; Trapani, Joseph A; Smyth, Mark J; Darcy, Phillip K; Atadja, Peter W; Henderson, Michael A; Johnstone, Ricky W; Haynes, Nicole M

    2017-05-15

    Histone deacetylase inhibitors (HDACi) may engage host immunity as one basis for their antitumor effects. Herein, we demonstrate an application of this concept using the HDACi panobinostat to augment the antitumor efficacy of trastuzumab (anti-HER2) therapy, through both tumor cell autonomous and nonautonomous mechanisms. In HER2(+) tumors that are inherently sensitive to the cytostatic effects of trastuzumab, cotreatment with panobinostat abrogated AKT signaling and triggered tumor regression in mice that lacked innate and/or adaptive immune effector cells. However, the cooperative ability of panobinostat and trastuzumab to harness host anticancer immune defenses was essential for their curative activity in trastuzumab-refractory HER2(+) tumors. In trastuzumab-resistant HER2(+) AU565(pv) xenografts and BT474 tumors expressing constitutively active AKT, panobinostat enhanced the antibody-dependent cell-mediated cytotoxicity function of trastuzumab. IFNγ-mediated, CXCR3-dependent increases in tumor-associated NK cells underpinned the combined curative activity of panobinostat and trastuzumab in these tumors. These data highlight the immune-enhancing effects of panobinostat and provide compelling evidence that this HDACi can license trastuzumab to evoke NK-cell-mediated responses capable of eradicating trastuzumab-refractory HER2(+) tumors. Cancer Res; 77(10); 2594-606. ©2017 AACR. ©2017 American Association for Cancer Research.

  18. Enhancement of human sodium iodide symporter gene therapy for breast cancer by HDAC inhibitor mediated transcriptional modulation.

    PubMed

    Kelkar, Madhura G; Senthilkumar, Kalimuthu; Jadhav, Smita; Gupta, Sudeep; Ahn, Beyong-Cheol; De, Abhijit

    2016-01-18

    The aberrant expression of human sodium iodide symporter (NIS) in breast cancer (BC) has raised the possibility of using targeted radioiodide therapy. Here we investigate modulation of endogenous, functional NIS expression by histone deacetylase inhibitors (HDACi) in vitro and in vivo. Luciferase reporter based initial screening of six different HDACi shows 2-10 fold enhancement of NIS promoter activity in majority of the cell types tested. As a result of drug treatment, endogenous NIS transcript and protein shows profound induction in BC cells. To get an insight on the mechanism of such transcriptional activation, role of Stat4, CREB and other transcription factors are revealed by transcription factor profiling array. Further, NIS-mediated intracellular iodide uptake also enhances substantially (p < 0.05) signifying functional relevance of the transcriptional modulation strategy. Gamma camera imaging confirms 30% higher uptake in VPA or NaB treated BC tumor xenograft. Corroborating with such functional impact of NIS, significant reduction in cell survival (p < 0.005) is observed in VPA, NaB or CI994 drug and (131)I combination treatment in vivo indicating effective radioablation. Thus, for the first time this study reveals the mechanistic basis and demonstrates functional relevance of HDACi pre-treatment strategy in elevating NIS gene therapy approach for BC management in clinic.

  19. Enhancement of human sodium iodide symporter gene therapy for breast cancer by HDAC inhibitor mediated transcriptional modulation

    PubMed Central

    Kelkar, Madhura G.; Senthilkumar, Kalimuthu; Jadhav, Smita; Gupta, Sudeep; Ahn, Beyong-Cheol; De, Abhijit

    2016-01-01

    The aberrant expression of human sodium iodide symporter (NIS) in breast cancer (BC) has raised the possibility of using targeted radioiodide therapy. Here we investigate modulation of endogenous, functional NIS expression by histone deacetylase inhibitors (HDACi) in vitro and in vivo. Luciferase reporter based initial screening of six different HDACi shows 2–10 fold enhancement of NIS promoter activity in majority of the cell types tested. As a result of drug treatment, endogenous NIS transcript and protein shows profound induction in BC cells. To get an insight on the mechanism of such transcriptional activation, role of Stat4, CREB and other transcription factors are revealed by transcription factor profiling array. Further, NIS-mediated intracellular iodide uptake also enhances substantially (p < 0.05) signifying functional relevance of the transcriptional modulation strategy. Gamma camera imaging confirms 30% higher uptake in VPA or NaB treated BC tumor xenograft. Corroborating with such functional impact of NIS, significant reduction in cell survival (p < 0.005) is observed in VPA, NaB or CI994 drug and 131I combination treatment in vivo indicating effective radioablation. Thus, for the first time this study reveals the mechanistic basis and demonstrates functional relevance of HDACi pre-treatment strategy in elevating NIS gene therapy approach for BC management in clinic. PMID:26777440

  20. Cyclic tetrapeptide HDAC inhibitors as potential therapeutics for spinal muscular atrophy: Screening with iPSC-derived neuronal cells.

    PubMed

    Lai, Jiun-I; Leman, Luke J; Ku, Sherman; Vickers, Chris J; Olsen, Christian A; Montero, Ana; Ghadiri, M Reza; Gottesfeld, Joel M

    2017-08-01

    Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that is caused by inactivating mutations in the Survival of motor neuron 1 (SMN1) gene, resulting in decreased SMN protein expression. Humans possess a paralog gene, SMN2, which contains a splicing defect in exon 7 leading to diminished expression of full-length, fully functional SMN protein. Increasing SMN2 expression has been a focus of therapeutic development for SMA. Multiple studies have reported the efficacy of histone deacetylase inhibitors (HDACi) in this regard. However, clinical trials involving HDACi have been unsatisfactory, possibly because previous efforts to identify HDACi to treat SMA have employed non-neuronal cells as the screening platform. To address this issue, we generated an SMA-patient specific, induced pluripotent stem cell (iPSC) derived neuronal cell line that contains homogenous Tuj1+neurons. We screened a small library of cyclic tetrapeptide HDACi using this SMA neuronal platform and discovered compounds that elevate SMN2 expression by an impressive twofold or higher. These candidates are also capable of forming gems intranuclearly in SMA neurons, demonstrating biological activity. Our study identifies new potential HDACi therapeutics for SMA screened using a disease-relevant SMA neuronal cellular model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. HDAC inhibitor sodium butyrate sensitizes E1A+Ras-transformed cells to DNA damaging agents by facilitating formation and persistence of γH2AX foci.

    PubMed

    Abramova, Maria V; Svetlikova, Svetlana B; Kukushkin, Alexander N; Aksenov, Nikolai D; Pospelova, Tatiana V; Pospelov, Valery A

    2011-12-15

    HDAC inhibitors (HDACi) suppress the growth of tumor cells due to induction of cell cycle arrest, senescence or apoptosis. Recent data demonstrate that HDACi can interfere with DNA Damage Response (DDR) thereby sensitizing the cells to DNA damaging agents. Here, we show that HDACi sodium butyrate (NaBut) potentiates the formation of γH2AX foci predominantly in S-phase E1A+Ras cells. Accumulation of γH2AX foci sensitizes the cells toward such DNA damaging agents as irradiation (IR) and adriamycin. In fact, NaBut potentiates the persistence of γH2AX foci induced by genotoxic agents. The synergizing effects depend on DNA damaging factors and on the order of NaBut treatment. Indeed, NaBut treatment for 24 h leads to an accumulation of G 1-phase cells and a lack of S-phase cells, therefore, adriamycin, a powerful S-phase-specific inhibitor, when added to NaBut-treated cells, is unable to substantially add γH2AX foci. In contrast, IR produces both single- and double-strand DNA breaks at any stage of the cell cycle and was shown to increase γH2AX foci in NaBut-treated cells. Further, a lifetime of IR-induced γH2AX foci depends on the subsequent presence of HDACi. Correspondingly, NaBut withdrawal leads to the extinction of IR-induced γH2AX foci. This necessitates HDACi to hold the IR-induced γH2AX foci unrepaired. However, the IR-induced γH2AX foci persist after long-term NaBut treatment (72 h) even after washing the drug. Thus, although signaling pathways regulating H2AX phosphorylation in NaBut-treated cells remain to be investigated, the obtained results show that NaBut potentiates effects of DNA damaging agents by facilitating formation and persistence of γH2AX foci.

  2. Histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), enhances anti-tumor effects of the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib in triple-negative breast cancer cells.

    PubMed

    Min, Ahrum; Im, Seock-Ah; Kim, Debora Keunyoung; Song, Sang-Hyun; Kim, Hee-Jun; Lee, Kyung-Hun; Kim, Tae-Yong; Han, Sae-Won; Oh, Do-Youn; Kim, Tae-You; O'Connor, Mark J; Bang, Yung-Jue

    2015-03-07

    Olaparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, has been found to have therapeutic potential for treating cancers associated with impaired DNA repair capabilities, particularly those with deficiencies in the homologous recombination repair (HRR) pathway. Histone deacetylases (HDACs) are important for enabling functional HRR of DNA by regulating the expression of HRR-related genes and promoting the accurate assembly of HRR-directed sub-nuclear foci. Thus, HDAC inhibitors have recently emerged as a therapeutic agent for treating cancer by inhibiting DNA repair. Based on this, HDAC inhibition could be predicted to enhance the anti-tumor effect of PARP inhibitors in cancer cells by blocking the HRR pathway. We determined whether suberoylanilide hydroxamic acid (SAHA), a HDAC inhibitor, could enhance the anti-tumor effects of olaparib on breast cancer cell lines using a cytotoxic assay, cell cycle analysis, and Western blotting. We evaluated how exposure to SAHA affects the expression of HRR-associated genes. The accumulation of DNA double strand breaks (DSBs) induced by combination treatment was assessed. Induction of autophagy was monitored by imaging green fluorescent protein-tagged microtubule-associated protein 1A/1B-light chain 3 (LC3) expression following co-treatment with olaparib and SAHA. These in vitro data were validated in vivo using a human breast cancer xenograft model. Triple-negative breast cancer cell (TNBC) lines showed heterogeneous responses to the PARP and HDAC inhibitors. Co-administration of olaparib and SAHA synergistically inhibited the growth of TNBC cells that expressed functional Phosphatase and tensin homolog (PTEN). This effect was associated with down-regulation of the proliferative signaling pathway, increased apoptotic and autophagic cell death, and accumulation of DNA damage. The combined anti-tumor effect of olaparib and SAHA was also observed in a xenograft model. These data suggest that PTEN expression in TNBC cells can

  3. HDAC inhibitor SAHA normalizes the levels of VLCFAs in human skin fibroblasts from X-ALD patients and downregulates the expression of proinflammatory cytokines in Abcd1/2-silenced mouse astrocytes

    PubMed Central

    Singh, Jaspreet; Khan, Mushfiquddin; Singh, Inderjit

    2011-01-01

    X-adrenoleukodystrophy (X-ALD) is a peroxisomal metabolic disorder caused by mutations in the ABCD1 gene encoding the peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). The consistent metabolic abnormality in all forms of X-ALD is an inherited defect in the peroxisomal β-oxidation of very long chain FAs (VLCFAs >C22:0) and the resultant pathognomic accumulation of VLCFA. The accumulation of VLCFA leads to a neuroinflammatory disease process associated with demyelination of the cerebral white matter. The present study underlines the importance of a potent histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA) in inducing the expression of ABCD2 [adrenoleukodystrophy-related protein (ALDRP)], and normalizing the peroxisomal β-oxidation, as well as the saturated and monounsaturated VLCFAs in cultured human skin fibroblasts of X-ALD patients. The expression of ELOVL1, the single elongase catalyzing the synthesis of both saturated VLCFA (C26:0) and monounsaturated VLCFA (C26:1), was also reduced by SAHA treatment. In addition, using Abcd1/Abcd2-silenced mouse primary astrocytes, we also examined the effects of SAHA in VLCFA-induced inflammatory response. SAHA treatment decreased the inflammatory response as expression of inducible nitric oxide synthase, inflammatory cytokine, and activation of NF-κB in Abcd1/Abcd2-silenced mouse primary astrocytes was reduced. These observations indicate that SAHA corrects both the metabolic disease of VLCFA as well as secondary inflammatory disease; therefore, it may be an ideal drug candidate to be tested for X-ALD therapy in humans PMID:21891797

  4. HDAC inhibitor SAHA normalizes the levels of VLCFAs in human skin fibroblasts from X-ALD patients and downregulates the expression of proinflammatory cytokines in Abcd1/2-silenced mouse astrocytes.

    PubMed

    Singh, Jaspreet; Khan, Mushfiquddin; Singh, Inderjit

    2011-11-01

    X-adrenoleukodystrophy (X-ALD) is a peroxisomal metabolic disorder caused by mutations in the ABCD1 gene encoding the peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). The consistent metabolic abnormality in all forms of X-ALD is an inherited defect in the peroxisomal β-oxidation of very long chain FAs (VLCFAs >C22:0) and the resultant pathognomic accumulation of VLCFA. The accumulation of VLCFA leads to a neuroinflammatory disease process associated with demyelination of the cerebral white matter. The present study underlines the importance of a potent histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA) in inducing the expression of ABCD2 [adrenoleukodystrophy-related protein (ALDRP)], and normalizing the peroxisomal β-oxidation, as well as the saturated and monounsaturated VLCFAs in cultured human skin fibroblasts of X-ALD patients. The expression of ELOVL1, the single elongase catalyzing the synthesis of both saturated VLCFA (C26:0) and monounsaturated VLCFA (C26:1), was also reduced by SAHA treatment. In addition, using Abcd1/Abcd2-silenced mouse primary astrocytes, we also examined the effects of SAHA in VLCFA-induced inflammatory response. SAHA treatment decreased the inflammatory response as expression of inducible nitric oxide synthase, inflammatory cytokine, and activation of NF-κB in Abcd1/Abcd2-silenced mouse primary astrocytes was reduced. These observations indicate that SAHA corrects both the metabolic disease of VLCFA as well as secondary inflammatory disease; therefore, it may be an ideal drug candidate to be tested for X-ALD therapy in humans.

  5. NOX2-dependent ROS is required for HDAC5 nuclear efflux and contributes to HDAC4 nuclear efflux during intense repetitive activity of fast skeletal muscle fibers

    PubMed Central

    Liu, Yewei; Hernández-Ochoa, Erick O.; Randall, William R.

    2012-01-01

    Reactive oxygen species (ROS) have been linked to oxidation and nuclear efflux of class IIa histone deacetylase 4 (HDAC4) in cardiac muscle. Here we use HDAC-GFP fusion proteins expressed in isolated adult mouse flexor digitorum brevis muscle fibers to study ROS mediation of HDAC localization in skeletal muscle. H2O2 causes nuclear efflux of HDAC4-GFP or HDAC5-GFP, which is blocked by the ROS scavenger N-acetyl-l-cysteine (NAC). Repetitive stimulation with 100-ms trains at 50 Hz, 2/s (“50-Hz trains”) increased ROS production and caused HDAC4-GFP or HDAC5-GFP nuclear efflux. During 50-Hz trains, HDAC5-GFP nuclear efflux was completely blocked by NAC, but HDAC4-GFP nuclear efflux was only partially blocked by NAC and partially blocked by the calcium-dependent protein kinase (CaMK) inhibitor KN-62. Thus, during intense activity both ROS and CaMK play roles in nuclear efflux of HDAC4, but only ROS mediates HDAC5 nuclear efflux. The 10-Hz continuous stimulation did not increase the rate of ROS production and did not cause HDAC5-GFP nuclear efflux but promoted HDAC4-GFP nuclear efflux that was sensitive to KN-62 but not NAC and thus mediated by CaMK but not by ROS. Fibers from NOX2 knockout mice lacked ROS production and ROS-dependent nuclear efflux of HDAC5-GFP or HDAC4-GFP during 50-Hz trains but had unmodified Ca2+ transients. Our results demonstrate that ROS generated by NOX2 could play important roles in muscle remodeling due to intense muscle activity and that the nuclear effluxes of HDAC4 and HDAC5 are differentially regulated by Ca2+ and ROS during muscle activity. PMID:22648949

  6. Valproic Acid Improves Glucose Homeostasis by Increasing Beta-Cell Proliferation, Function, and Reducing its Apoptosis through HDAC Inhibition in Juvenile Diabetic Rat.

    PubMed

    Khan, Sabbir; Jena, Gopabandhu

    2016-09-01

    Recent evidence highlighted that there is a link between type-1 diabetes mellitus and histone deacetylases (HDACs) due to their involvement in beta-cell differentiation, proliferation, and function. The present study aimed to investigate the protective role of valproic acid (VPA) on beta-cell proliferation, function, and apoptosis in juvenile diabetic rat. Diabetes was induced in juvenile Sprague-Dawley rats by streptozotocin (75 mg/kg, i.p.) and VPA was administered at the doses of 150 and 300 mg/kg/day for 3 weeks by oral route. Various biochemical parameters, cellular alterations, and protein expression as well as apoptosis were assessed using different assays. VPA treatment significantly decreased plasma glucose, beta-cell damage, and apoptosis as well as increased the beta-cell function, insulin level/expression. The present study demonstrated that VPA improves beta-cell proliferation and function as well as reduces beta-cell apoptosis through HDAC inhibition. Our findings provide evidence that VPA may be useful for the treatment of juvenile diabetes. © 2016 Wiley Periodicals, Inc.

  7. PP2A Regulates HDAC4 Nuclear Import

    PubMed Central

    Paroni, Gabriela; Cernotta, Nadia; Dello Russo, Claudio; Gallinari, Paola; Pallaoro, Michele; Foti, Carmela; Talamo, Fabio; Orsatti, Laura; Steinkühler, Christian

    2008-01-01

    Different signal-regulated serine/threonine kinases phosphorylate class II histone deacetylases (HDACs) to promote nuclear export, cytosolic accumulation, and activation of gene transcription. However, little is known about mechanisms operating in the opposite direction, which, possibly through phosphatases, should promote class II HDACs nuclear entry and subsequent gene repression. Here we show that HDAC4 forms a complex with the PP2A holoenzyme Cα, Aα, B/PR55α. In vitro and in vivo binding studies demonstrate that the N-terminus of HDAC4 interacts with the catalytic subunit of PP2A. HDAC4 is dephosphorylated by PP2A and experiments using okadaic acid or RNA interference have revealed that PP2A controls HDAC4 nuclear import. Moreover, we identified serine 298 as a putative phosphorylation site important for HDAC4 nuclear import. The HDAC4 mutant mimicking phosphorylation of serine 298 is defective in nuclear import. Mutation of serine 298 to alanine partially rescues the defect in HDAC4 nuclear import observed in cells with down-regulated PP2A. These observations suggest that PP2A, via the dephosphorylation of multiple serines including the 14-3-3 binding sites and serine 298, controls HDAC4 nuclear import. PMID:18045992

  8. Chemical genetic strategy identifies histone deacetylase 1 (HDAC1) and HDAC2 as therapeutic targets in sickle cell disease

    PubMed Central

    Bradner, James E.; Mak, Raymond; Tanguturi, Shyam K.; Mazitschek, Ralph; Haggarty, Stephen J.; Ross, Kenneth; Chang, Cindy Y.; Bosco, Jocelyn; West, Nathan; Morse, Elizabeth; Shen, John Paul; Kwiatkowski, Nicholas P.; Gheldof, Nele; Dekker, Job; DeAngelo, Daniel J.; Carr, Steven A.; Schreiber, Stuart L.; Golub, Todd R.; Ebert, Benjamin L.

    2010-01-01

    The worldwide burden of sickle cell disease is enormous, with over 200,000 infants born with the disease each year in Africa alone. Induction of fetal hemoglobin is a validated strategy to improve symptoms and complications of this disease. The development of targeted therapies has been limited by the absence of discrete druggable targets. We developed a unique bead-based strategy for the identification of inducers of fetal hemoglobin transcripts in primary human erythroid cells. A small-molecule screen of bioactive compounds identified remarkable class-associated activity among histone deacetylase (HDAC) inhibitors. Using a chemical genetic strategy combining focused libraries of biased chemical probes and reverse genetics by RNA interference, we have identified HDAC1 and HDAC2 as molecular targets mediating fetal hemoglobin induction. Our findings suggest the potential of isoform-selective inhibitors of HDAC1 and HDAC2 for the treatment of sickle cell disease. PMID:20616024

  9. Chemical genetic strategy identifies histone deacetylase 1 (HDAC1) and HDAC2 as therapeutic targets in sickle cell disease.

    PubMed

    Bradner, James E; Mak, Raymond; Tanguturi, Shyam K; Mazitschek, Ralph; Haggarty, Stephen J; Ross, Kenneth; Chang, Cindy Y; Bosco, Jocelyn; West, Nathan; Morse, Elizabeth; Lin, Katherine; Shen, John Paul; Kwiatkowski, Nicholas P; Gheldof, Nele; Dekker, Job; DeAngelo, Daniel J; Carr, Steven A; Schreiber, Stuart L; Golub, Todd R; Ebert, Benjamin L

    2010-07-13

    The worldwide burden of sickle cell disease is enormous, with over 200,000 infants born with the disease each year in Africa alone. Induction of fetal hemoglobin is a validated strategy to improve symptoms and complications of this disease. The development of targeted therapies has been limited by the absence of discrete druggable targets. We developed a unique bead-based strategy for the identification of inducers of fetal hemoglobin transcripts in primary human erythroid cells. A small-molecule screen of bioactive compounds identified remarkable class-associated activity among histone deacetylase (HDAC) inhibitors. Using a chemical genetic strategy combining focused libraries of biased chemical probes and reverse genetics by RNA interference, we have identified HDAC1 and HDAC2 as molecular targets mediating fetal hemoglobin induction. Our findings suggest the potential of isoform-selective inhibitors of HDAC1 and HDAC2 for the treatment of sickle cell disease.

  10. Role of 5′TG3′-interacting factors (TGIFs) in Vorinostat (HDAC inhibitor)-mediated Corneal Fibrosis Inhibition

    PubMed Central

    Sharma, Ajay; Sinha, Nishant R.; Siddiqui, Saad

    2015-01-01

    Purpose We have previously reported that vorinostat, an FDA-approved, clinically used histone deacetylase (HDAC) inhibitor, attenuates corneal fibrosis in vivo in rabbits by blocking transforming growth factor β (TGFβ). The 5′TG3′-interacting factors (TGIFs) are transcriptional repressors of TGFβ1 signaling via the Smad pathway. The present study was designed to explore the expression of TGIFs in human corneal fibroblasts and to investigate their role in mediating the antifibrotic effect of vorinostat. Methods Human corneal fibroblast cultures were generated from donor corneas. RNA isolation, cDNA preparation, and PCR were performed to detect the presence of TGIF1 and TGIF2 transcripts. The cultures were exposed to vorinostat (2.5 µM) to test its effect on TGIF mRNA and protein levels using qPCR and immunoblotting. Myofibroblast formation was induced with TGFβ1 (5 ng/ml) treatment under serum-free conditions. The changes in fibrosis parameters were quantified by measuring fibrosis marker α-smooth muscle actin (αSMA) mRNA and protein levels with qPCR, immunostaining, and immunoblotting. Smad2/3/4 and TGIF knockdowns were performed using pre-validated RNAi/siRNAs and a commercially available transfection reagent. Results Human corneal fibroblasts showed the expression of TGIF1 and TGIF2. Vorinostat (2.5 µM) caused a 2.8–3.3-fold increase in TGIF1 and TGIF2 mRNA levels and a 1.4–1.8-fold increase in TGIF1 and TGIF2 protein levels. Vorinostat treatment also caused a significant increase in acetylhistone H3 and acetylhistone H4. Vorinostat-induced increases in TGIF1 and TGIF2 were accompanied by a concurrent decrease in corneal fibrosis, as indicated by a decrease in αSMA mRNA by 83±7.7% and protein levels by 97±5%. The RNAi-mediated knockdown of Smad2, Smad3, and Smad4 markedly attenuated TGFβ1-evoked transdifferentiation of fibroblasts to myofibroblasts. The siRNA-mediated knockdown of TGIF1 and TGIF2 neutralized vorinostat-evoked decreases in

  11. Insights from Comprehensive Multiple Receptor Docking to HDAC8

    PubMed Central

    Brunsteiner, Michael; Petukhov, Pavel A.

    2013-01-01

    A systematic investigation of available crystal structures of HDAC8 and of the influence of different receptor structures and docking protocols is presented. The study shows that the open conformation of HDAC8 may be preferred by ligands with flexible surface binding groups as such conformation allows the ligands to minimize their exposure to solvent upon binding. This observation allowed us to rationalize excellent potency of the pyrazole-based inhibitors compared to that of the isoxazole-based inhibitors. PMID:22431224

  12. HDAC6 promotes cell proliferation and confers resistance to temozolomide in glioblastoma.

    PubMed

    Wang, Zhihao; Hu, Pengchao; Tang, Fang; Lian, Haiwei; Chen, Xiong; Zhang, Yingying; He, Xiaohua; Liu, Wanhong; Xie, Conghua

    2016-08-28

    Histone deacetylases are considered to be among the most promising targets in drug development for cancer therapy. Histone deacetylase 6 (HDAC6) is a unique cytoplasmic enzyme that regulates many biological processes involved in tumorigenesis through its deacetylase and ubiquitin-binding activities. Here, we report that HDAC6 is overexpressed in glioblastoma tissues and cell lines. Overexpression of HDAC6 promotes the proliferation and spheroid formation of glioblastoma cells. HDAC6 overexpression confers resistance to temozolomide (TMZ) mediated cell proliferation inhibition and apoptosis induction. Conversely, knockdown of HDAC6 inhibits cell proliferation, impairs spheroid formation and sensitizes glioblastoma cells to TMZ. The inhibition of HDAC6 deacetylase activity by selective inhibitors inhibits the proliferation of glioblastoma cells and induces apoptosis. HDAC6 selective inhibitors can sensitize glioblastoma cells to TMZ. Moreover, we showed that HDAC6 mediated EGFR stabilization might partly account for its oncogenic role in glioblastoma. TMZ resistant glioblastoma cells showed higher expression of HDAC6 and more activation of EGFR. HDAC6 inhibitors decrease EGFR protein levels and impair the activation of the EGFR pathway. Taken together, our results suggest that the inhibition of HDAC6 may be a promising strategy for the treatment of glioblastoma. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Selective inhibition of HDAC2 by magnesium valproate attenuates cardiac hypertrophy.

    PubMed

    Raghunathan, Suchi; Goyal, Ramesh K; Patel, Bhoomika M

    2017-03-01

    The regulatory paradigm in cardiac hypertrophy involves alterations in gene expression that is mediated by chromatin remodeling. Various data suggest that class I and class II histone deacetylases (HDACs) play opposing roles in the regulation of hypertrophic pathways. To address this, we tested the effect of magnesium valproate (MgV), an HDAC inhibitor with 5 times more potency on class I HDACs. Cardiac hypertrophy was induced by partial abdominal aortic constriction in Wistar rats, and at the end of 6 weeks, we evaluated hypertrophic, hemodynamic, and oxidative stress parameters, and mitochondrial DNA concentration. Treatment with MgV prevented cardiac hypertrophy, improved hemodynamic functions, prevented oxidative stress, and increased mitochondrial DNA concentration. MgV treatment also increased the survival rate of the animals as depicted by the Kaplan-Meier curve. Improvement in hypertrophy due to HDAC inhibition was further confirmed by HDAC mRNA expression studies, which revealed that MgV decreases expression of pro-hypertrophic HDAC (i.e., HDAC2) without altering the expression of anti-hypertrophic HDAC5. Selective class I HDAC inhibition is required for controlling cardiac hypertrophy. Newer HDAC inhibitors that are class I inhibitors and class II promoters can be designed to obtain "pan" or "dual" natural HDAC "regulators".

  14. Transgenic overexpression of Hdac3 in the heart produces increased postnatal cardiac myocyte proliferation but does not induce hypertrophy.

    PubMed

    Trivedi, Chinmay M; Lu, Min Min; Wang, Qiaohong; Epstein, Jonathan A

    2008-09-26

    Class I and II histone deacetylases (HDACs) play vital roles in regulating cardiac development, morphogenesis, and hypertrophic responses. Although the roles of Hdac1 and Hdac2, class I HDACs, in cardiac hyperplasia, growth, and hypertrophic responsiveness have been reported, the role in the heart of Hdac3, another class I HDAC, has been less well explored. Here we report that myocyte-specific overexpression of Hdac3 in mice results in cardiac abnormalities at birth. Hdac3 overexpression produces thickening of ventricular myocardium, especially the interventricular septum, and reduction of both ventricular cavities in newborn hearts. Our data suggest that increased thickness of myocardium in Hdac3-transgenic (Hdac3-Tg) mice is due to increased cardiomyocyte hyperplasia without hypertrophy. Hdac3 overexpression inhibits several cyclin-dependent kinase inhibitors, including Cdkn1a, Cdkn1b, Cdkn1c, Cdkn2b, and Cdkn2c. Hdac3-Tg mice did not develop cardiac hypertrophy at 3 months of age, unlike previously reported Hdac2-Tg mice. Further, Hdac3 overexpression did not augment isoproterenol-induced cardiac hypertrophy when compared with wild-type littermates. These findings identify Hdac3 as a novel regulator of cardiac myocyte proliferation during cardiac development.

  15. A mechanistic approach to explore novel HDAC1 inhibitor using pharmacophore modeling, 3D- QSAR analysis, molecular docking, density functional and molecular dynamics simulation study.

    PubMed

    Choubey, Sanjay K; Jeyaraman, Jeyakanthan

    2016-11-01

    Deregulated epigenetic activity of Histone deacetylase 1 (HDAC1) in tumor development and carcinogenesis pronounces it as promising therapeutic target for cancer treatment. HDAC1 has recently captured the attention of researchers owing to its decisive role in multiple types of cancer. In the present study a multistep framework combining ligand based 3D-QSAR, molecular docking and Molecular Dynamics (MD) simulation studies were performed to explore potential compound with good HDAC1 binding affinity. Four different pharmacophore hypotheses Hypo1 (AADR), Hypo2 (AAAH), Hypo3 (AAAR) and Hypo4 (ADDR) were obtained. The hypothesis Hypo1 (AADR) with two hydrogen bond acceptors (A), one hydrogen bond donor (D) and one aromatics ring (R) was selected to build 3D-QSAR model on the basis of statistical parameter. The pharmacophore hypothesis produced a statistically significant QSAR model, with co-efficient of correlation r(2)=0.82 and cross validation correlation co-efficient q(2)=0.70. External validation result displays high predictive power with r(2) (o) value of 0.88 and r(2) (m) value of 0.58 to carry out further in silico studies. Virtual screening result shows ZINC70450932 as the most promising lead where HDAC1 interacts with residues Asp99, His178, Tyr204, Phe205 and Leu271 forming seven hydrogen bonds. A high docking score (-11.17kcal/mol) and lower docking energy -37.84kcal/mol) displays the binding efficiency of the ligand. Binding free energy calculation was done using MM/GBSA to access affinity of ligands towards protein. Density Functional Theory was employed to explore electronic features of the ligands describing intramolcular charge transfer reaction. Molecular dynamics simulation studies at 50ns display metal ion (Zn)-ligand interaction which is vital to inhibit the enzymatic activity of the protein.

  16. A regimen combining the Wee1 inhibitor AZD1775 with HDAC inhibitors targets human acute myeloid leukemia cells harboring various genetic mutations

    PubMed Central

    Zhou, Liang; Zhang, Yu; Chen, Shuang; Kmieciak, Maciej; Leng, Yun; Lin, Hui; Rizzo, Kathryn A.; Dumur, Catherine I.; Ferreira-Gonzalez, Andrea; Dai, Yun; Grant, Steven

    2015-01-01

    AZD1775 targets the cell cycle checkpoint kinase Wee1 and potentiates genotoxic agent cytotoxicity through p53-dependent or -independent mechanisms. Here, we report that AZD1775 interacted synergistically with histone deacetylase inhibitors (HDACIs e.g., Vorinostat), which interrupt the DNA damage response (DDR), to kill p53-wild type or -deficient as well as FLT3-ITD leukemia cells in association with pronounced Wee1 inhibition and diminished cdc2/Cdk1 Y15 phosphorylation. Similarly, Wee1 shRNA knock-down significantly sensitized cells to HDACIs. While AZD1775 induced Chk1 activation, reflected by markedly increased Chk1 S296/S317/S345 phosphorylation leading to inhibitory T14 phosphorylation of cdc2/Cdk1, these compensatory responses were sharply abrogated by HDACIs. This was accompanied by premature mitotic entry, multiple mitotic abnormalities, and accumulation of early S-phase cells displaying increased newly replicated DNA, culminating in robust DNA damage and apoptosis. The regimen was active against patient-derived AML cells harboring either wild type or mutant p53, and various NGS-defined mutations. Primitive CD34+/CD123+/CD38− populations enriched for leukemia-initiating progenitors, but not normal CD34+ hematopoietic cells, were highly susceptible to this regimen. Finally, combining AZD1775 with Vorinostat in AML murine xenografts significantly reduced tumor burden and prolonged animal survival. A strategy combining Wee1 with HDACI inhibition warrants further investigation in AML with poor prognostic genetic aberrations. PMID:25283841

  17. Cathepsin H-Mediated Degradation of HDAC4 for Matrix Metalloproteinase Expression in Hepatic Stellate Cells: Implications of Epigenetic Suppression of Matrix Metalloproteinases in Fibrosis through Stabilization of Class IIa Histone Deacetylases.

    PubMed

    Yang, Zemin; Liu, Yu; Qin, Lan; Wu, Pengfei; Xia, Zanxian; Luo, Mei; Zeng, Yilan; Tsukamoto, Hidekazu; Ju, Zongyun; Su, Danmei; Kang, Han; Xiao, Zhixiong; Zheng, Sujun; Duan, Zhongping; Hu, Richard; Wang, Qiang; Pandol, Stephen J; Han, Yuan-Ping

    2017-02-01

    In three-dimensional extracellular matrix, mesenchymal cells including hepatic stellate cells (HSCs) gain the ability to express matrix metalloproteinases (MMPs) on injury signals. In contrast, in myofibroblastic HSCs in fibrotic liver, many MMP genes are silenced into an epigenetically nonpermissive state. The mechanism by which the three-dimensional extracellular matrix confers the MMP genes into an epigenetically permissive state has not been well characterized. In continuation of previous work, we show here that the up-regulation of MMP genes is mediated through degradation of class IIa histone deacetylases (HDACs) by certain cysteine cathepsins (Cts). In three-dimensional extracellular matrix culture, CtsH, among other cysteine cathepsins, was up-regulated and localized as puncta in the nuclear and cytoplasmic compartments in a complex with HDAC4 for its degradation. Conversely, along with HSC trans-differentiation, CtsH and CtsL were progressively down-regulated, whereas HDAC4 was concurrently stabilized. The inhibition of cysteine cathepsins by specific proteinase inhibitors or chloroquine, which raises cellular pH, restored HDAC4. Recombinant CtsH could break down HDAC4 in the transfected cells and in vitro at acidic pH. In human cirrhotic liver, activated HSCs express high levels of class IIa HDACs but little CtsH. We propose that cysteine cathepsin-mediated degradation of class IIa HDACs plays a key role in the modulation of MMP expression/suppression and HSC functions in tissue injury and fibrosis.

  18. Penicillin inhibitors of purple acid phosphatase.

    PubMed

    Faridoon; Hussein, Waleed M; Ul Islam, Nazar; Guddat, Luke W; Schenk, Gerhard; McGeary, Ross P

    2012-04-01

    Purple acid phosphatases (PAPs) are binuclear metallohydrolases that have a multitude of biological functions and are found in fungi, bacteria, plants and animals. In mammals, PAP activity is linked with bone resorption and over-expression can lead to bone disorders such as osteoporosis. PAP is therefore an attractive target for the development of drugs to treat this disease. A series of penicillin conjugates, in which 6-aminopenicillanic acid was acylated with aromatic acid chlorides, has been prepared and assayed against pig PAP. The binding mode of most of these conjugates is purely competitive, and some members of this class have potencies comparable to the best PAP inhibitors yet reported. The structurally related penicillin G was shown to be neither an inhibitor nor a substrate for pig PAP. Molecular modelling has been used to examine the binding modes of these compounds in the active site of the enzyme and to rationalise their activities. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  19. PLGA-PEG Nanoparticles Coated with Anti-CD45RO and Loaded with HDAC Plus Protease Inhibitors Activate Latent HIV and Inhibit Viral Spread

    NASA Astrophysics Data System (ADS)

    Tang, Xiaolong; Liang, Yong; Liu, Xinkuang; Zhou, Shuping; Liu, Liang; Zhang, Fujina; Xie, Chunmei; Cai, Shuyu; Wei, Jia; Zhu, Yongqiang; Hou, Wei

    2015-10-01

    Activating HIV-1 proviruses in latent reservoirs combined with inhibiting viral spread might be an effective anti-HIV therapeutic strategy. Active specific delivery of therapeutic drugs into cells harboring latent HIV, without the use of viral vectors, is a critical challenge to this objective. In this study, nanoparticles of poly(lactic-co-glycolic acid)-polyethylene glycol diblock copolymers conjugated with anti-CD45RO antibody and loaded with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and/or protease inhibitor nelfinavir (Nel) were tested for activity against latent virus in vitro. Nanoparticles loaded with SAHA, Nel, and SAHA + Nel were characterized in terms of size, surface morphology, zeta potential, entrapment efficiency, drug release, and toxicity to ACH-2 cells. We show that SAHA- and SAHA + Nel-loaded nanoparticles can target latently infected CD4+ T-cells and stimulate virus production. Moreover, nanoparticles loaded with SAHA + NEL were capable of both activating latent virus and inhibiting viral spread. Taken together, these data demonstrate the potential of this novel reagent for targeting and eliminating latent HIV reservoirs.

  20. Inactivation of HDAC1 or HDAC2 induces gamma globin expression without altering cell cycle or proliferation.

    PubMed

    Esrick, Erica B; McConkey, Marie; Lin, Katherine; Frisbee, Alyse; Ebert, Benjamin L

    2015-07-01

    Other than hydroxyurea, no pharmacologic agents are clinically available for fetal hemoglobin (HbF) induction in sickle cell disease (SCD). An optimal candidate would induce HbF without causing cell cycle inhibition and would act independently of hydroxyurea in order to yield additional HbF induction when combined. We explored whether inhibition of histone deacetylase (HDAC) 1 or HDAC2 could achieve these goals. In human erythroid progenitor cells, shRNA knockdown of the HDAC1 or HDAC2 genes induced gamma globin, without altering cellular proliferation in vitro, and without altering cell cycle phase. Treatment with hydroxyurea in combination with HDAC2 knockdown yielded a further increase in gamma globin expression. Additionally, when CD34+ cells were treated with both hydroxyurea and MS-275 (an inhibitor of HDAC 1, 2, and 3), an additive induction of relative gamma globin expression was achieved. Our findings support further clinical investigation of HDAC inhibitors in combination with hydroxyurea in SCD patients. © 2015 Wiley Periodicals, Inc.

  1. HDAC3 regulates stability of estrogen receptor α mRNA

    SciTech Connect

    Oie, Shohei; Matsuzaki, Kazuya; Yokoyama, Wataru; Murayama, Akiko; Yanagisawa, Junn

    2013-03-08

    Highlights: ► HDAC inhibitors decrease the stability of ERα mRNA in MCF-7 cells. ► HDAC3 is involved in maintaining ERα mRNA stability in MCF-7 cells. ► ERα mRNA instability by knockdown of HDAC3 reduces the estrogen-dependent proliferation of ERα-positive MCF-7 cells. ► HDAC3 specific inhibitor will be one of new drugs for ERα-positive breast cancers. -- Abstract: Estrogen receptor alpha (ERα) expression is a risk factor for breast cancer. HDAC inhibitors have been demonstrated to down-regulate ERα expression in ERα-positive breast cancer cell lines, but the molecular mechanisms are poorly understood. Here, we showed that HDAC inhibitors decrease the stability of ERα mRNA, and that knockdown of HDAC3 decreases the stability of ERα mRNA and suppresses estrogen-dependent proliferation of ERα-positive MCF-7 breast cancer cells. In the Oncomine database, expression levels of HDAC3 in ERα-positive tumors are higher than those in ERα-negative tumors, thus suggesting that HDAC3 is necessary for ERα mRNA stability, and is involved in the estrogen-dependent proliferation of ERα-positive tumors.

  2. Combined HDAC1 and HDAC2 Depletion Promotes Retinal Ganglion Cell Survival After Injury Through Reduction of p53 Target Gene Expression

    PubMed Central

    Suter, Ueli

    2015-01-01

    Histones deacetylases (HDACs), besides their function as epigenetic regulators, deacetylate and critically regulate the activity of nonhistone targets. In particular, HDACs control partially the proapoptotic activity of p53 by balancing its acetylation state. HDAC inhibitors have revealed neuroprotective properties in different models, but the exact mechanisms of action remain poorly understood. We have generated a conditional knockout mouse model targeting retinal ganglion cells (RGCs) to investigate specifically the functional role of HDAC1 and HDAC2 in an acute model of optic nerve injury. Our results demonstrate that combined HDAC1 and HDAC2 ablation promotes survival of axotomized RGCs. Based on global gene expression analyses, we identified the p53-PUMA apoptosis-inducing axis to be strongly activated in axotomized mouse RGCs. Specific HDAC1/2 ablation inhibited this apoptotic pathway by impairing the crucial acetylation status of p53 and reducing PUMA expression, thereby contributing to the ensuing enhanced neuroprotection due to HDAC1/2 depletion. HDAC1/2 inhibition and the affected downstream signaling components emerge as specific targets for developing therapeutic strategies in neuroprotection. PMID:26129908

  3. Clinacanthus nutans Protects Cortical Neurons Against Hypoxia-Induced Toxicity by Downregulating HDAC1/6.

    PubMed

    Tsai, Hsin-Da; Wu, Jui-Sheng; Kao, Mei-Han; Chen, Jin-Jer; Sun, Grace Y; Ong, Wei-Yi; Lin, Teng-Nan

    2016-09-01

    Many population-based epidemiological studies have unveiled an inverse correlation between intake of herbal plants and incidence of stroke. C. nutans is a traditional herbal medicine widely used for snake bite, viral infection and cancer in Asian countries. However, its role in protecting stroke damage remains to be studied. Despite of growing evidence to support epigenetic regulation in the pathogenesis and recovery of stroke, a clear understanding of the underlying molecular mechanisms is still lacking. In the present study, primary cortical neurons were subjected to in vitro oxygen-glucose deprivation (OGD)-reoxygenation and hypoxic neuronal death was used to investigate the interaction between C. nutans and histone deacetylases (HDACs). Using pharmacological agents (HDAC inhibitor/activator), loss-of-function (HDAC siRNA) and gain-of-function (HDAC plasmid) approaches, we demonstrated an early induction of HDAC1/2/3/8 and HDAC6 in neurons after OGD insult. C. nutans extract selectively inhibited HDAC1 and HDAC6 expression and attenuated neuronal death. Results of reporter analysis further revealed that C. nutans suppressed HDAC1 and HDAC6 transcription. Besides ameliorating neuronal death, C. nutans also protected astrocytes and endothelial cells from hypoxic-induced cell death. In summary, results support ability for C. nutans to suppress post-hypoxic HDACs activation and mitigate against OGD-induced neuronal death. This study further opens a new avenue for the use of herbal medicines to regulate epigenetic control of brain injury.

  4. Deacetylase-Independent Function of HDAC3 in Transcription and Metabolism Requires Nuclear Receptor Corepressor

    PubMed Central

    Sun, Zheng; Feng, Dan; Fang, Bin; Mullican, Shannon E.; You, Seo-Hee; Lim, Hee-Woong; Everett, Logan J.; Nabel, Christopher S.; Li, Yun; Selvakumaran, Vignesh; Won, Kyoung-Jae; Lazar, Mitchell A.

    2013-01-01

    Histone deacetylases (HDACs) are believed to regulate gene transcription by catalyzing deacetylation reactions. HDAC3 depletion in mouse liver upregulates lipogenic genes and results in severe hepatosteatosis. Here we show that pharmacologic HDAC inhibition in primary hepatocytes causes histone hyperacetylation but does not upregulate expression of HDAC3 target genes. Meanwhile, deacetylase-dead HDAC3 mutants can rescue hepatosteatosis and repress lipogenic genes expression in HDAC3-depleted mouse liver, demonstrating that histone acetylation is insufficient to activate gene transcription. Mutations abolishing interactions with the nuclear receptor corepressor (NCOR or SMRT) render HDAC3 nonfunctional in vivo. Additionally, liver-specific knockout of NCOR, but not SMRT, causes metabolic and transcriptomal alterations resembling those of mice without hepatic HDAC3, demonstrating that interaction with NCOR is essential for deacetylase-independent function of HDAC3. These findings highlight non-enzymatic roles of a major HDAC in transcriptional regulation in vivo and warrant reconsideration of the mechanism of action of HDAC inhibitors. PMID:24268577

  5. Valproic Acid Neuroprotection in the 6-OHDA Model of Parkinson's Disease Is Possibly Related to Its Anti-Inflammatory and HDAC Inhibitory Properties

    PubMed Central

    Ximenes, José Christian Machado; Neves, Kelly Rose Tavares; Leal, Luzia Kalyne A. M.; do Carmo, Marta Regina Santos; Brito, Gerly Anne de Castro; Naffah-Mazzacoratti, Maria da Graça; Cavalheiro, Ésper Abrão; Viana, Glauce Socorro de Barros

    2015-01-01

    Parkinson's disease is a neurodegenerative disorder where the main hallmark is the dopaminergic neuronal loss. Besides motor symptoms, PD also causes cognitive decline. Although current therapies focus on the restoration of dopamine levels in the striatum, prevention or disease-modifying therapies are urgently needed. Valproic acid (VA) is a wide spectrum antiepileptic drug, exerting many biochemical and physiological effects. It has been shown to inhibit histone deacetylase which seems to be associated with the drug neuroprotective action. The objectives were to study the neuroprotective properties of VA in a model of Parkinson's disease, consisting in the unilateral striatal injection of the neurotoxin 6-OHDA. For that, male Wistar rats (250 g) were divided into the groups: sham-operated (SO), untreated 6-OHDA-lesioned, and 6-OHDA-lesioned treated with VA (25 or 50 mg/kg). Oral treatments started 24 h after the stereotaxic surgery and continued daily for 2 weeks, when the animals were subjected to behavioral evaluations (apomorphine-induced rotations and open-field tests). Then, they were sacrificed and had their mesencephalon, striatum, and hippocampus dissected for neurochemical (DA and DOPAC determinations), histological (Fluoro-Jade staining), and immunohistochemistry evaluations (TH, OX-42, GFAP, TNF-alpha, and HDAC). The results showed that VA partly reversed behavioral and neurochemical alterations observed in the untreated 6-OHDA-lesioned rats. Besides, VA also decreased neuron degeneration in the striatum and reversed the TH depletion observed in the mesencephalon of the untreated 6-OHDA groups. This neurotoxin increased the OX-42 and GFAP immunoreactivities in the mesencephalon, indicating increased microglia and astrocyte reactivities, respectively, which were reversed by VA. In addition, the immunostainings for TNF-alpha and HDAC demonstrated in the untreated 6-OHDA-lesioned rats were also decreased after VA treatments. These results were

  6. Histone deacetylase 3 (HDAC 3) as emerging drug target in NF-κB-mediated inflammation

    PubMed Central

    Leus, Niek G.J.; Zwinderman, Martijn R.H.; Dekker, Frank J.

    2016-01-01

    Activation of inflammatory gene expression is regulated, among other factors, by post-translational modifications of histone proteins. The most investigated type of histone modifications are lysine acetylations. Histone deacetylases (HDACs) remove acetylations from lysines, thereby influencing (inflammatory) gene expression. Intriguingly, apart from histones, HDACs also target non-histone proteins. The nuclear factor κB (NF-κB) pathway is an important regulator in the expression of numerous inflammatory genes, and acetylation plays a crucial role in regulating its responses. Several studies have shed more light on the role of HDAC 1-3 in inflammation with a particular pro-inflammatory role for HDAC 3. Nevertheless, the HDAC-NF-κB interactions in inflammatory signalling have not been fully understood. An important challenge in targeting the regulatory role of HDACs in the NF-κB pathway is the development of highly potent small molecules that selectively target HDAC iso-enzymes. This review focuses on the role of HDAC 3 in (NF-κB-mediated) inflammation and NF-κB lysine acetylation. In addition, we address the application of frequently used small molecule HDAC inhibitors as an approach to attenuate inflammatory responses, and their potential as novel therapeutics. Finally, recent progress and future directions in medicinal chemistry efforts aimed at HDAC 3-selective inhibitors are discussed. PMID:27371876

  7. A salt bridge turns off the foot-pocket in class-II HDACs.

    PubMed

    Zhou, Jingwei; Yang, Zuolong; Zhang, Fan; Luo, Hai-Bin; Li, Min; Wu, Ruibo

    2016-08-21

    Histone Deacetylases (HDACs) are promising anticancer targets and several selective inhibitors have been created based on the architectural differences of foot-pockets among HDACs. However, the "gate-keeper" of foot-pockets is still controversial. Herein, it is for the first time revealed that a conserved R-E salt bridge plays a critical role in keeping foot-pockets closed in class-II HDACs by computational simulations. This finding is further substantiated by our mutagenesis experiments.

  8. Inhibitors of abscisic acid 8'-hydroxylase.

    PubMed

    Cutler, A J; Rose, P A; Squires, T M; Loewen, M K; Shaw, A C; Quail, J W; Krochko, J E; Abrams, S R

    2000-11-07

    Structural analogues of the phytohormone (+)-abscisic acid (ABA) have been synthesized and tested as inhibitors of the catabolic enzyme (+)-ABA 8'-hydroxylase. Assays employed microsomes from suspension-cultured corn cells. Four of the analogues [(+)-8'-acetylene-ABA, (+)-9'-propargyl-ABA, (-)-9'-propargyl-ABA, and (+)-9'-allyl-ABA] proved to be suicide substrates of ABA 8'-hydroxylase. For each suicide substrate, inactivation required NADPH, increased with time, and was blocked by addition of the natural substrate, (+)-ABA. The most effective suicide substrate was (+)-9'-propargyl-ABA (K(I) = 0.27 microM). Several analogues were competitive inhibitors of ABA 8'-hydroxylase, of which the most effective was (+)-8'-propargyl-ABA (K(i) = 1.1 microM). Enzymes in the microsomal extracts also hydroxylated (-)-ABA at the 7'-position at a low rate. This activity was not inhibited by the suicide substrates, showing that the 7'-hydroxylation of (-)-ABA was catalyzed by a different enzyme from that which catalyzed 8'-hydroxylation of (+)-ABA. Based on the results described, a simple model for the positioning of substrates in the active site of ABA 8'-hydroxylase is proposed. In a representative physiological assay, inhibition of Arabidopsis thaliana seed germination, (+)-9'-propargyl-ABA and (+)-8'-acetylene-ABA exhibited substantially stronger hormonal activity than (+)-ABA itself.

  9. Insecticidal activities of histone deacetylase inhibitors against a dipteran parasite of sheep, Lucilia cuprina.

    PubMed

    Bagnall, Neil H; Hines, Barney M; Lucke, Andrew J; Gupta, Praveer K; Reid, Robert C; Fairlie, David P; Kotze, Andrew C

    2017-04-01

    Histone deacetylase inhibitors (HDACi) are being investigated for the control of various human parasites. Here we investigate their potential as insecticides for the control of a major ecto-parasite of sheep, the Australian sheep blowfly, Lucilia cuprina. We assessed the ability of HDACi from various chemical classes to inhibit the development of blowfly larvae in vitro, and to inhibit HDAC activity in nuclear protein extracts prepared from blowfly eggs. The HDACi prodrug romidepsin, a cyclic depsipeptide that forms a thiolate, was the most potent inhibitor of larval growth, with equivalent or greater potency than three commercial blowfly insecticides. Other HDACi with potent activity were hydroxamic acids (trichostatin, CUDC-907, AR-42), a thioester (KD5170), a disulphide (Psammaplin A), and a cyclic tetrapeptide bearing a ketone (apicidin). On the other hand, no insecticidal activity was observed for certain other hydroxamic acids, fatty acids, and the sesquiterpene lactone parthenolide. The structural diversity of the 31 hydroxamic acids examined here revealed some structural requirements for insecticidal activity; for example, among compounds with flexible linear zinc-binding extensions, greater potency was observed in the presence of branched capping groups that likely make multiple interactions with the blowfly HDAC enzymes. The insecticidal activity correlated with inhibition of HDAC activity in blowfly nuclear protein extracts, indicating that the toxicity was most likely due to inhibition of HDAC enzymes in the blowfly larvae. The inhibitor potencies against blowfly larvae are different from inhibition of human HDACs, suggesting some selectivity for human over blowfly HDACs, and a potential for developing compounds with the inverse selectivity. In summary, these novel findings support blowfly HDAC enzymes as new targets for blowfly control, and point to development of HDAC inhibitors as a promising new class of insecticides.

  10. Development of Inhibitors of Salicylic Acid Signaling.

    PubMed

    Jiang, Kai; Kurimoto, Tetsuya; Seo, Eun-kyung; Miyazaki, Sho; Nakajima, Masatoshi; Nakamura, Hidemitsu; Asami, Tadao

    2015-08-19

    Salicylic acid (SA) plays important roles in the induction of systemic acquired resistance (SAR) in plants. Determining the mechanism of SAR will extend our understanding of plant defenses against pathogens. We recently reported that PAMD is an inhibitor of SA signaling, which suppresses the expression of the pathogenesis-related PR genes and is expected to facilitate the understanding of SA signaling. However, PAMD strongly inhibits plant growth. To minimize the side effects of PAMD, we synthesized a number of PAMD derivatives, and identified compound 4 that strongly suppresses the expression of the PR genes with fewer adverse effects on plant growth than PAMD. We further showed that the adverse effects on plant growth were partially caused the stabilization of DELLA, which is also related to the pathogen responses. These results indicate that compound 4 would facilitate our understanding of SA signaling and its cross talk with other plant hormones.

  11. Targeted inhibition of HDAC8 increases the doxorubicin sensitivity of neuroblastoma cells via up regulation of miR-137.

    PubMed

    Zhao, Gang; Wang, Guoliang; Bai, Hongmin; Li, Tiandong; Gong, Fanghe; Yang, Huan; Wen, Jinchong; Wang, Weimin

    2017-02-20

    Histone deacetylases (HDACs) have been suggested to be potential therapeutic targets for cancer treatment. Recent studies revealed that HDAC8 expression was associated with poor prognostic markers and poor overall survival rate of neuroblastoma (NB). Our present study revealed that among the four members of class I HDACs, HDAC8 is significantly over expressed in NB cells as compared with the normal fibroblast 3T3 cells or primary normal human astrocytes (NHA) cells. Targeted inhibition of HDAC8 by its specific siRNA (si-HDAC8) can inhibit the in vitro growth of NB cells. Furthermore, si-HDAC8 significantly increases the sensitivity of NB cells to doxorubicin (Dox). Silencing of HDAC8 can increase the expression of miR-137, which has been suggested to mediate the Dox sensitivity of NB cells. Knockdown of miR-137 can attenuate si-HDAC8 enhanced Dox sensitivity. Further, si-HDAC8 can also inhibit the expression of multi-drug resistance gene 1 (MDR1). While knockdown of miR-137 can attenuate si-HDAC8 induced down regulation of MDR1. Collectively, our data revealed that targeted inhibition of HDAC8 can suppress the growth of NB cells and increase Dox sensitivity via up regulation of miR-137 and suppression of MDR1. Therefor, combination of HDAC8 inhibitor will be helpful to elevate the treatment outcome of NB patients.

  12. Tcf7l2/Tcf4 Transcriptional Repressor Function Requires HDAC Activity in the Developing Vertebrate CNS

    PubMed Central

    Wang, Hui; Matise, Michael P.

    2016-01-01

    The generation of functionally distinct neuronal subtypes within the vertebrate central nervous system (CNS) requires the precise regulation of progenitor gene expression in specific neuronal territories during early embryogenesis. Accumulating evidence has implicated histone deacetylase (HDAC) proteins in cell specification, proliferation, and differentiation in diverse embryonic and adult tissues. However, although HDAC proteins have shown to be expressed in the developing vertebrate neural tube, their specific role in CNS neural progenitor fate specification remains unclear. Prior work from our lab showed that the Tcf7l2/Tcf4 transcription factor plays a key role in ventral progenitor lineage segregation by differential repression of two key specification factors, Nkx2.2 and Olig2. In this study, we found that administration of HDAC inhibitors (Valproic Acid (VPA), Trichostatin-A (TSA), or sodium butyrate) in chick embryos in ovo disrupted normal progenitor gene segregation in the developing neural tube, indicating that HDAC activity is required for this process. Further, using functional and pharmacological approaches in vivo, we found that HDAC activity is required for the differential repression of Nkx2.2 and Olig2 by Tcf7l2/Tcf4. Finally, using dominant-negative functional assays, we provide evidence that Tcf7l2/Tcf4 repression also requires Gro/TLE/Grg co-repressor factors. Together, our data support a model where the transcriptional repressor activity of Tcf7l2/Tcf4 involves functional interactions with both HDAC and Gro/TLE/Grg co-factors at specific target gene regulatory elements in the developing neural tube, and that this activity is required for the proper segregation of the Nkx2.2 (p3) and Olig2 (pMN) expressing cells from a common progenitor pool. PMID:27668865

  13. Histone Deacetylase (HDAC) 10 Suppresses Cervical Cancer Metastasis through Inhibition of Matrix Metalloproteinase (MMP) 2 and 9 Expression*

    PubMed Central

    Song, Chenlin; Zhu, Songcheng; Wu, Chuanyue; Kang, Jiuhong

    2013-01-01

    Aberrant expression of histone deacetylases (HDACs) is associated with carcinogenesis. Some HDAC inhibitors are widely considered as promising anticancer therapeutics. A major obstacle for development of HDAC inhibitors as highly safe and effective anticancer therapeutics is that our current knowledge on the contributions of different HDACs in various cancer types remains scant. Here we report that the expression level of HDAC10 was significantly lower in patients exhibiting lymph node metastasis compared with that in patients lacking lymph node metastasis in human cervical squamous cell carcinoma. Forced expression of HDAC10 in cervical cancer cells significantly inhibited cell motility and invasiveness in vitro and metastasis in vivo. Mechanistically, HDAC10 suppresses expression of matrix metalloproteinase (MMP) 2 and 9 genes, which are known to be critical for cancer cell invasion and metastasis. At the molecular level, HDAC10 binds to MMP2 and -9 promoter regions, reduces the histone acetylation level, and inhibits the binding of RNA polymerase II to these regions. Furthermore, an HDAC10 mutant lacking histone deacetylase activity failed to mimic the functions of full-length protein. These results identify a critical role of HDAC10 in suppression of cervical cancer metastasis, underscoring the importance of developing isoform-specific HDAC inhibitors for treatment of certain cancer types such as cervical squamous cell carcinoma. PMID:23897811

  14. Lunularic acid, a common endogenous growth inhibitor of liverworts.

    PubMed

    Pryce, R J

    1971-12-01

    By gas-liquid chromotography and thin layer chromatography, an endogenous growth inhibitor of Lunularia cruciata has been detected in seven other representatives of the class of liverworts. All liverworts so far examined have been found to contain lunularic acid. Evidence for the identity of the previously isolated, but unidentified, endogenous growth inhibitor of Marchantia polymorpha and lunularic acid is presented.

  15. Radio-Sensitizing Effects of Novel Histone De-Acetylase Inhibitors in Prostate Cancer

    DTIC Science & Technology

    2005-09-01

    phenylacetic acid and butyric acid respectively as the lead compound (Fig. 1) have been used in the present study. Since, these inhibitors have aromatic chain...compoundinhibitors ONOH butyrylamino)ben an tide N-[:ý Phenylacetic F1 HDAC inhibifion: IC0. 16 nNM VAD-18 acid H DU- 14,5 growth inhibition. ICu, 110 ntM...combination with radiation to augment clinical efficacy and/or to reduce toxicity. The HDAC inhibitors- phenyl butyrate (38), sodium butyrate (39

  16. Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis.

    PubMed

    Van Beneden, Katrien; Geers, Caroline; Pauwels, Marina; Mannaerts, Inge; Wissing, Karl M; Van den Branden, Christiane; van Grunsven, Leo A

    2013-09-01

    Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Inhibitors of Histone Deacetylases Enhance Neurotoxicity of DNA Damage

    PubMed Central

    Vashishta, A.

    2014-01-01

    The nonselective inhibitors of class I/II histone deacetylases (HDACs) including trichostatin A and the clinically used suberoylanilide hydroxamic acid (SAHA, vorinostat) are neuroprotective in several models of neuronal injury. Here, we report that in cultured cortical neurons from newborn rats and in the cerebral cortex of whole neonate rats, these HDAC inhibitors exacerbated cytotoxicity of the DNA double-strand break (DSB)-inducing anticancer drug etoposide by enhancing apoptosis. Similar neurotoxic interactions were also observed in neurons that were treated with other DNA damaging drugs including cisplatin and camptothecin. In addition, in rat neonates, SAHA increased cortical neuron apoptosis that was induced by a single injection of the NMDA receptor antagonist dizocilpine (MK801). In etoposide-treated neurons, the nonselective HDAC inhibition resulted in more DSBs. It also potentiated etoposide-induced accumulation and phosphorylation of the pro-apoptotic transcription factor p53. Moreover, nonselective HDAC inhibition exacerbated neuronal apoptosis that was induced by the overexpressed p53. Importantly, such effects cannot be fully explained by inhibition of HDAC1, which is known to play a role in DSB repair and regulation of p53. The specific HDAC1 inhibitor MS275 only moderately enhanced etoposide-induced neuronal death. Although in etoposide-treated neurons MS275 increased DSBs, it did not affect activation of p53. Our findings suggest that besides HDAC1, there are other class I/II HDACs that participate in neuronal DNA damage response attenuating neurotoxic consequences of genotoxic insults to the developing brain. PMID:25063076

  18. Loss of deacetylation activity of Hdac6 affects emotional behavior in mice.

    PubMed

    Fukada, Masahide; Hanai, Atsuko; Nakayama, Atsuo; Suzuki, Takayoshi; Miyata, Naoki; Rodriguiz, Ramona M; Wetsel, William C; Yao, Tso-Pang; Kawaguchi, Yoshiharu

    2012-01-01

    Acetylation is mediated by acetyltransferases and deacetylases, and occurs not only on histones but also on diverse proteins. Although histone acetylation in chromatin structure and transcription has been well studied, the biological roles of non-histone acetylation remain elusive. Histone deacetylase 6 (Hdac6), a member of the histone deacetylase (HDAC) family, is a unique deacetylase that localizes to cytoplasm and functions in many cellular events by deacetylating non-histone proteins including α-tubulin, Hsp90, and cortactin. Since robust expression of Hdac6 is observed in brain, it would be expected that Hdac6-mediated reversible acetylation plays essential roles in CNS. Here we demonstrate the crucial roles of Hdac6 deacetylase activity in the expression of emotional behavior in mice. We found that Hdac6-deficient mice exhibit hyperactivity, less anxiety, and antidepressant-like behavior in behavioral tests. Moreover, administration of Hdac6-specific inhibitor replicated antidepressant-like behavior in mice. In good agreement with behavioral phenotypes of Hdac6-deficient mice, Hdac6 dominantly localizes to the dorsal and median raphe nuclei, which are involved in emotional behaviors. These findings suggest that HDAC6-mediated reversible acetylation might contribute to maintain proper neuronal activity in serotonergic neurons, and also provide a new therapeutic target for depression.

  19. Sepsis and glucocorticoids upregulate p300 and downregulate HDAC6 expression and activity in skeletal muscle.

    PubMed

    Alamdari, Nima; Smith, Ira J; Aversa, Zaira; Hasselgren, Per-Olof

    2010-08-01

    Muscle wasting during sepsis is in part regulated by glucocorticoids. In recent studies, treatment of cultured muscle cells in vitro with dexamethasone upregulated expression and activity of p300, a histone acetyl transferase (HAT), and reduced expression and activity of the histone deacetylases-3 (HDAC3) and -6, changes that favor hyperacetylation. Here, we tested the hypothesis that sepsis and glucocorticoids regulate p300 and HDAC3 and -6 in skeletal muscle in vivo. Because sepsis-induced metabolic changes are particularly pronounced in white, fast-twitch skeletal muscle, most experiments were performed in extensor digitorum longus muscles. Sepsis in rats upregulated p300 mRNA and protein levels, stimulated HAT activity, and reduced HDAC6 expression and HDAC activity. The sepsis-induced changes in p300 and HDAC expression were prevented by the glucocorticoid receptor antagonist RU38486. Treatment of rats with dexamethasone increased expression of p300 and HAT activity, reduced expression of HDAC3 and -6, and inhibited HDAC activity. Finally, treatment with the HDAC inhibitor trichostatin A resulted in increased muscle proteolysis and expression of the ubiquitin ligase atrogin-1. Taken together, our results suggest for the first time that sepsis-induced muscle wasting may be regulated by glucocorticoid-dependent hyperacetylation caused by increased p300 and reduced HDAC expression and activity. The recent development of pharmacological HDAC activators may provide a novel avenue to prevent and treat muscle wasting in sepsis and other catabolic conditions.

  20. HDAC2 promotes the migration and invasion of non-small cell lung cancer cells via upregulation of fibronectin.

    PubMed

    Li, Li; Mei, Dr Tonghua; Zeng, Yun

    2016-12-01

    Recent studies indicated that histone deacetylases (HDACs) can modulate the tumorigenesis and development of cancer cells. We evaluated the expression of class I HDACs in non-small cell lung cancer (NSCLC) cells and found that HDAC2 was significantly increased in NSCLC cells as compared with the normal bronchial epithelial cell line BEAS-2B. Silencing of HDAC2 by its specific siRNAs can significantly inhibit the in vitro migration and invasion of A549 and H1395 cells. While over expression of HDAC2 by transfection of pcDNA/HDAC2 plasmid can trigger the motility of NSCLC cells. Over expression of HDAC2 increased the protein and mRNA expression of firbronectin (FN), which can accelerate the metastasis of cancer cells. Similarly, knock down of HDAC2 suppressed the expression of FN. The inhibitor of NF-κB, while not ERK1/2 or PI3K/Akt, attenuated HDAC2 induced up regulation of FN and invasion of NSCLC cells. Furthermore, HDAC2 can markedly increase both mRNA and protein levels of p65 in NSCLC cells. Collectively, our data revealed that HDAC2 can trigger migration and invasion of NSCLC cells via up regulation FN through activation of NF-κB. It suggested HDAC2 might be a potential therapeutic target for the drug development of NSCLC patients.

  1. HDAC6 contributes to pathological responses of heart and skeletal muscle to chronic angiotensin-II signaling.

    PubMed

    Demos-Davies, Kimberly M; Ferguson, Bradley S; Cavasin, Maria A; Mahaffey, Jennifer H; Williams, Sarah M; Spiltoir, Jessica I; Schuetze, Katherine B; Horn, Todd R; Chen, Bo; Ferrara, Claudia; Scellini, Beatrice; Piroddi, Nicoletta; Tesi, Chiara; Poggesi, Corrado; Jeong, Mark Y; McKinsey, Timothy A

    2014-07-15

    Little is known about the function of the cytoplasmic histone deacetylase HDAC6 in striated muscle. Here, we addressed the role of HDAC6 in cardiac and skeletal muscle remodeling induced by the peptide hormone angiotensin II (ANG II), which plays a central role in blood pressure control, heart failure, and associated skeletal muscle wasting. Comparable with wild-type (WT) mice, HDAC6 null mice developed cardiac hypertrophy and fibrosis in response to ANG II. However, whereas WT mice developed systolic dysfunction upon treatment with ANG II, cardiac function was maintained in HDAC6 null mice treated with ANG II for up to 8 wk. The cardioprotective effect of HDAC6 deletion was mimicked in WT mice treated with the small molecule HDAC6 inhibitor tubastatin A. HDAC6 null mice also exhibited improved left ventricular function in the setting of pressure overload mediated by transverse aortic constriction. HDAC6 inhibition appeared to preserve systolic function, in part, by enhancing cooperativity of myofibrillar force generation. Finally, we show that HDAC6 null mice are resistant to skeletal muscle wasting mediated by chronic ANG-II signaling. These findings define novel roles for HDAC6 in striated muscle and suggest potential for HDAC6-selective inhibitors for the treatment of cardiac dysfunction and muscle wasting in patients with heart failure. Copyright © 2014 the American Physiological Society.

  2. HDAC6 contributes to pathological responses of heart and skeletal muscle to chronic angiotensin-II signaling

    PubMed Central

    Demos-Davies, Kimberly M.; Ferguson, Bradley S.; Cavasin, Maria A.; Mahaffey, Jennifer H.; Williams, Sarah M.; Spiltoir, Jessica I.; Schuetze, Katherine B.; Horn, Todd R.; Chen, Bo; Ferrara, Claudia; Scellini, Beatrice; Piroddi, Nicoletta; Tesi, Chiara; Poggesi, Corrado; Jeong, Mark Y.

    2014-01-01

    Little is known about the function of the cytoplasmic histone deacetylase HDAC6 in striated muscle. Here, we addressed the role of HDAC6 in cardiac and skeletal muscle remodeling induced by the peptide hormone angiotensin II (ANG II), which plays a central role in blood pressure control, heart failure, and associated skeletal muscle wasting. Comparable with wild-type (WT) mice, HDAC6 null mice developed cardiac hypertrophy and fibrosis in response to ANG II. However, whereas WT mice developed systolic dysfunction upon treatment with ANG II, cardiac function was maintained in HDAC6 null mice treated with ANG II for up to 8 wk. The cardioprotective effect of HDAC6 deletion was mimicked in WT mice treated with the small molecule HDAC6 inhibitor tubastatin A. HDAC6 null mice also exhibited improved left ventricular function in the setting of pressure overload mediated by transverse aortic constriction. HDAC6 inhibition appeared to preserve systolic function, in part, by enhancing cooperativity of myofibrillar force generation. Finally, we show that HDAC6 null mice are resistant to skeletal muscle wasting mediated by chronic ANG-II signaling. These findings define novel roles for HDAC6 in striated muscle and suggest potential for HDAC6-selective inhibitors for the treatment of cardiac dysfunction and muscle wasting in patients with heart failure. PMID:24858848

  3. Synergistic antineoplastic effect of DLC1 tumor suppressor protein and histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), on prostate and liver cancer cells: perspectives for therapeutics.

    PubMed

    Zhou, Xiaoling; Yang, Xu-Yu; Popescu, Nicholas C

    2010-04-01

    Inactivation of tumor suppressor genes is a major contributing alteration in the initiation or progression of cancer. The human tumor suppressor gene DLC1 (deleted in liver cancer 1) is frequently downregulated or silenced in multiple cancers, predominantly by epigenetic mechanisms. With the current considerable interest and progress in epigenetic therapy, a number of promising antineoplastic agents, particularly histone deacetylase (HDAC) inhibitors, have been developed and used successfully in clinical trials. Both DLC1 and HDAC inhibitors exert antineoplastic functions, and their combined action could be exploited for a more effective cancer therapy. To evaluate the potential benefits of this approach, we examined the antineoplastic effects of adenoviral (Ad)-DLC1-mediated transduction and exposure to suberoylanilide hydroxamic acid (SAHA), a powerful HDAC inhibitor, in two human cancer cell lines that lack intrinsic DLC1 expression, 22Rv1 prostate cancer cells and 7703K human hepatocellular carcinoma cells. Consistent with the oncosuppressive function of DLC1 in several cancers, including prostate and liver cancer, transduction of 22Rv1 and 7703K cells with an Ad-DLC1 expression vector resulted in alterations of cell morphology, induction of apoptosis, and inhibition of cell proliferation, migration, and anchorage-independent growth. A low concentration of SAHA (5 microM) efficiently restored the expression of DLC1 in 22Rv1 cells that lack DLC1 expression due to histone deacetylation but had a minimal effect in 7703K cells in which silencing of the DLC1 gene is due mainly to promoter hypermethylation. Regardless of the epigenetic mechanism of DLC1 inactivation, SAHA treatment of DLC1-transduced cells had a synergistic inhibitory effect on tumor cell proliferation and tumorigenesis in both cell lines. In 22Rv1 cells, this combination regimen nearly abolished the formation of colonies in semisolid media as a measure of tumorigenicity in vitro. Current in vitro

  4. New benzothiazole/thiazole-containing hydroxamic acids as potent histone deacetylase inhibitors and antitumor agents.

    PubMed

    Tung, Truong Thanh; Oanh, Dao Thi Kim; Dung, Phan Thi Phuong; Hue, Van Thi My; Park, Sang Ho; Han, Byung Woo; Kim, Youngsoo; Hong, Jin-Tae; Han, Sang-Bae; Nam, Nguyen-Hai

    2013-12-01

    Results from clinical studies have demonstrated that inhibitors of histone deacetylase (HDAC) enzymes possess promise for the treatment of several types of cancer. Zolinza(®) (widely known as SAHA) has been approved by the FDA for the treatment of T-cell lymphoma. As a continuity of our ongoing research to find novel small molecules to target these important enzymes, we synthesized a series of benzothiazole-containing analogues of SAHA and found several compounds with very potent anticancer cytotoxicity. In this study, three more compounds of this type, including N(1)-(6-chlorobenzo[d]thiazol-2-yl)-N(8)-hydroxyoctanediamide (3a), N(1)-[6-(trifluoromethyl)benzo[d]thiazol-2-yl]-N(8)-hydroxyoctanediamide (3b) and N(1)-(thiazol-2-yl)-N(8)-hydroxyoctanediamide (6) were synthesized and evaluated for HDAC inhibition and cytotoxic activities. All three compounds showed very potent HDAC inhibitory effects. Docking revealed that both two compounds 3a, 3b showed higher affinities towards HDAC(8) compared to SAHA. In vitro, compound 3a exhibited cytotoxicity equipotent to SAHA against five human cancer cell lines. In term of in vivo activity, compound 3a demonstrated equivalent efficacy to SAHA in mouse xenograft model.

  5. HDAC6 Brain Mapping with [(18)F]Bavarostat Enabled by a Ru-Mediated Deoxyfluorination.

    PubMed

    Strebl, Martin G; Campbell, Arthur J; Zhao, Wen-Ning; Schroeder, Frederick A; Riley, Misha M; Chindavong, Peter S; Morin, Thomas M; Haggarty, Stephen J; Wagner, Florence F; Ritter, Tobias; Hooker, Jacob M

    2017-09-27

    Histone deacetylase 6 (HDAC6) function and dysregulation have been implicated in the etiology of certain cancers and more recently in central nervous system (CNS) disorders including Rett syndrome, Alzheimer's and Parkinson's diseases, and major depressive disorder. HDAC6-selective inhibitors have therapeutic potential, but in the CNS drug space the development of highly brain penetrant HDAC inhibitors has been a persistent challenge. Moreover, no tool exists to directly characterize HDAC6 and its related biology in the living human brain. Here, we report a highly brain penetrant HDAC6 inhibitor, Bavarostat, that exhibits excellent HDAC6 selectivity (>80-fold over all other Zn-containing HDAC paralogues), modulates tubulin acetylation selectively over histone acetylation, and has excellent brain penetrance. We further demonstrate that Bavarostat can be radiolabeled with (18)F by deoxyfluorination through in situ formation of a ruthenium π-complex of the corresponding phenol precursor: the only method currently suitable for synthesis of [(18)F]Bavarostat. Finally, by using [(18)F]Bavarostat in a series of rodent and nonhuman primate imaging experiments, we demonstrate its utility for mapping HDAC6 in the living brain, which sets the stage for first-in-human neurochemical imaging of this important target.

  6. Performance Characteristics of Borate Fatty Acid Formulations as Mold Inhibitors

    Treesearch

    Robert D. Coleman; Vina Yang; Carol A. Clausen

    2013-01-01

    The combination of boric acid (BA) or disodium octaborate tetrahydrate (DOT) and a fatty acid (FA) such as heptanoic, octanoic, and nonanoic acids (C7–C9) is an effective treatment solution for protecting wood structures against mold. BA or DOT alone have substantial potency against insects and decay fungi, but have negligible or no mold inhibitor activity. However,...

  7. Opposing Effects of Valproic Acid Treatment Mediated by Histone Deacetylase Inhibitor Activity in Four Transgenic X. laevis Models of Retinitis Pigmentosa.

    PubMed

    Vent-Schmidt, Ruanne Y J; Wen, Runxia H; Zong, Zusheng; Chiu, Colette N; Tam, Beatrice M; May, Christopher G; Moritz, Orson L

    2017-01-25

    Retinitis pigmentosa (RP) is an inherited retinal degeneration (RD) that leads to blindness for which no treatment is available. RP is frequently caused by mutations in Rhodopsin; in some animal models, RD is exacerbated by light. Valproic acid (VPA) is a proposed treatment for RP and other neurodegenerative disorders, with a phase II trial for RP under way. However, the therapeutic mechanism is unclear, with minimal research supporting its use in RP. We investigated the effects of VPA on Xenopus laevis models of RP expressing human P23H, T17M, T4K, and Q344ter rhodopsins, which are associated with RP in humans. VPA ameliorated RD associated with P23H rhodopsin and promoted clearing of mutant rhodopsin from photoreceptors. The effect was equal to that of dark rearing, with no additive effect observed. Rescue of visual function was confirmed by electroretinography. In contrast, VPA exacerbated RD caused by T17M rhodopsin in light, but had no effect in darkness. Effects in T4K and Q344ter rhodopsin models were also negative. These effects of VPA were paralleled by treatment with three additional histone deacetylase (HDAC) inhibitors, but not other antipsychotics, chemical chaperones, or VPA structural analogues. In WT retinas, VPA treatment increased histone H3 acetylation. In addition, electron microscopy showed increased autophagosomes in rod inner segments with HDAC inhibitor (HDACi) treatment, potentially linking the therapeutic effects in P23H rhodopsin animals and negative effects in other models with autophagy. Our results suggest that the success or failure of VPA treatment is dependent on genotype and that HDACi treatment is contraindicated for some RP cases.SIGNIFICANCE STATEMENT Retinitis pigmentosa (RP) is an inherited, degenerative retinal disease that leads to blindness for which no therapy is available. We determined that valproic acid (VPA), currently undergoing a phase II trial for RP, has both beneficial and detrimental effects in animal models of

  8. Interfacial inhibitors of protein-nucleic acid interactions.

    PubMed

    Pommier, Yves; Marchand, Christophe

    2005-07-01

    This essay develops the paradigm of "Interfacial Inhibitors" (Pommier and Cherfils, TiPS, 2005, 28: 136) for inhibitory drugs beside orthosteric (competitive or non-competitive) and allosteric inhibitors. Interfacial inhibitors bind with high selectivity to a binding site involving two or more macromolecules within macromolecular complexes undergoing conformational changes. Interfacial binding traps (generally reversibly) a transition state of the complex, resulting in kinetic inactivation. The exemplary case of interfacial inhibitor of protein-DNA interface is camptothecin and its clinical derivatives. We will also provide examples generalizing the interfacial inhibitor concept to inhibitors of topoisomerase II (anthracyclines, ellipticines, epipodophyllotoxins), gyrase (quinolones, ciprofloxacin, norfloxacin), RNA polymerases (alpha-amanitin and actinomycin D), and ribosomes (antibiotics such as streptomycin, hygromycin B, tetracycline, kirromycin, fusidic acid, thiostrepton, and possibly cycloheximide). We discuss the implications of the interfacial inhibitor concept for drug discovery.

  9. Histone Deacetylase Inhibitors Antagonize Distinct Pathways to Suppress Tumorigenesis of Embryonal Rhabdomyosarcoma

    PubMed Central

    Vleeshouwer-Neumann, Terra; Phelps, Michael; Bammler, Theo K.; MacDonald, James W.; Jenkins, Isaac; Chen, Eleanor Y.

    2015-01-01

    Embryonal rhabdomyosarcoma (ERMS) is the most common soft tissue cancer in children. The prognosis of patients with relapsed or metastatic disease remains poor. ERMS genomes show few recurrent mutations, suggesting that other molecular mechanisms such as epigenetic regulation might play a major role in driving ERMS tumor biology. In this study, we have demonstrated the diverse roles of histone deacetylases (HDACs) in the pathogenesis of ERMS by characterizing effects of HDAC inhibitors, trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; also known as vorinostat) in vitro and in vivo. TSA and SAHA suppress ERMS tumor growth and progression by inducing myogenic differentiation as well as reducing the self-renewal and migratory capacity of ERMS cells. Differential expression profiling and pathway analysis revealed downregulation of key oncogenic pathways upon HDAC inhibitor treatment. By gain-of-function, loss-of-function, and chromatin immunoprecipitation (ChIP) studies, we show that Notch1- and EphrinB1-mediated pathways are regulated by HDACs to inhibit differentiation and enhance migratory capacity of ERMS cells, respectively. Our study demonstrates that aberrant HDAC activity plays a major role in ERMS pathogenesis. Druggable targets in the molecular pathways affected by HDAC inhibitors represent novel therapeutic options for ERMS patients. PMID:26636678

  10. Histone Acetylation Inhibitors Promote Axon Growth in Adult DRG neurons

    PubMed Central

    Lin, Shen; Nazif, Kutaiba; Smith, Alexander; Baas, Peter W; Smith, George M

    2015-01-01

    Intrinsic mechanisms that guide damaged axons to regenerate following spinal cord injury remain poorly understood. Manipulation of posttranslational modifications of key proteins in mature neurons could re-invigorate growth machinery after injury. One such modification is acetylation, a reversible process controlled by two enzyme families acting in opposition, the Histone Deacetylases (HDACs) and the Histone Acetyl Transferases (HATs). While acetylated histones in the nucleus is associated with upregulation of growth promoting genes, de-acetylated tubulin in the axoplasm is associated with more labile microtubules, conducive to axon growth. In this study we investigated the effects of HAT inhibitors and HDAC inhibitors on cultured adult dorsal root ganglia (DRG) neurons. We found that inhibition of HATs, using Anacardic Acid or CPTH2, improved axon outgrowth, while inhibition of HDACs using TSA or Tubacin, inhibited axon growth. Furthermore, Anacardic Acid increased the number of axons able to cross an inhibitory chondroitin sulfate proteoglycan (CSPG) border. Histone acetylation, but not tubulin acetylation levels, was affected by HAT inhibitors, whereas tubulin acetylation levels were increased in the presence of HDAC inhibitor Tubacin. Although microtubule stabilizing drug taxol did not have an effect on the lengths of DRG axons, nocodazole decreased axon lengths. While the mechanistic basis will require future studies, our data show that inhibitors of HAT can augment axon growth in adult DRG neurons, with the potential of aiding axon growth over inhibitory substrates produced by the glial scar. PMID:25702820

  11. Mechanical stimulation orchestrates the osteogenic differentiation of human bone marrow stromal cells by regulating HDAC1.

    PubMed

    Wang, J; Wang, C D; Zhang, N; Tong, W X; Zhang, Y F; Shan, S Z; Zhang, X L; Li, Q F

    2016-05-12

    Mechanical stimulation and histone deacetylases (HDACs) have essential roles in regulating the osteogenic differentiation of bone marrow stromal cells (BMSCs) and bone formation. However, little is known regarding what regulates HDAC expression and therefore the osteogenic differentiation of BMSCs during osteogenesis. In this study, we investigated whether mechanical loading regulates HDAC expression directly and examined the role of HDACs in mechanical loading-triggered osteogenic differentiation and bone formation. We first studied the microarrays of samples from patients with osteoporosis and found that the NOTCH pathway and skeletal development gene sets were downregulated in the BMSCs of patients with osteoporosis. Then we demonstrated that mechanical stimuli can regulate osteogenesis and bone formation both in vivo and in vitro. NOTCH signaling was upregulated during cyclic mechanical stretch (CMS)-induced osteogenic differentiation, whereas HDAC1 protein expression was downregulated. The perturbation of HDAC1 expression also had a significant effect on matrix mineralization and JAG1-mediated Notch signaling, suggesting that HDAC1 acts as an endogenous attenuator of Notch signaling in the mechanotransduction of BMSCs. Chromatin immunoprecipitation (ChIP) assay results suggest that HDAC1 modulates the CMS-induced histone H3 acetylation level at the JAG1 promoter. More importantly, we found an inhibitory role of Hdac1 in regulating bone formation in response to hindlimb unloading in mice, and pretreatment with an HDAC1 inhibitor partly rescued the osteoporosis caused by mechanical unloading. Our results demonstrate, for the first time, that mechanical stimulation orchestrates genes expression involved in the osteogenic differentiation of BMSCs via the direct regulation of HDAC1, and the therapeutic inhibition of HDAC1 may be an efficient strategy for enhancing bone formation under mechanical stimulation.

  12. Mechanical stimulation orchestrates the osteogenic differentiation of human bone marrow stromal cells by regulating HDAC1

    PubMed Central

    Wang, J; Wang, C D; Zhang, N; Tong, W X; Zhang, Y F; Shan, S Z; Zhang, X L; Li, Q F

    2016-01-01

    Mechanical stimulation and histone deacetylases (HDACs) have essential roles in regulating the osteogenic differentiation of bone marrow stromal cells (BMSCs) and bone formation. However, little is known regarding what regulates HDAC expression and therefore the osteogenic differentiation of BMSCs during osteogenesis. In this study, we investigated whether mechanical loading regulates HDAC expression directly and examined the role of HDACs in mechanical loading-triggered osteogenic differentiation and bone formation. We first studied the microarrays of samples from patients with osteoporosis and found that the NOTCH pathway and skeletal development gene sets were downregulated in the BMSCs of patients with osteoporosis. Then we demonstrated that mechanical stimuli can regulate osteogenesis and bone formation both in vivo and in vitro. NOTCH signaling was upregulated during cyclic mechanical stretch (CMS)-induced osteogenic differentiation, whereas HDAC1 protein expression was downregulated. The perturbation of HDAC1 expression also had a significant effect on matrix mineralization and JAG1-mediated Notch signaling, suggesting that HDAC1 acts as an endogenous attenuator of Notch signaling in the mechanotransduction of BMSCs. Chromatin immunoprecipitation (ChIP) assay results suggest that HDAC1 modulates the CMS-induced histone H3 acetylation level at the JAG1 promoter. More importantly, we found an inhibitory role of Hdac1 in regulating bone formation in response to hindlimb unloading in mice, and pretreatment with an HDAC1 inhibitor partly rescued the osteoporosis caused by mechanical unloading. Our results demonstrate, for the first time, that mechanical stimulation orchestrates genes expression involved in the osteogenic differentiation of BMSCs via the direct regulation of HDAC1, and the therapeutic inhibition of HDAC1 may be an efficient strategy for enhancing bone formation under mechanical stimulation. PMID:27171263

  13. HDAC3 Is a Critical Negative Regulator of Long-Term Memory Formation

    PubMed Central

    McQuown, Susan C.; Barrett, Ruth M.; Matheos, Dina P.; Post, Rebecca J.; Rogge, George A.; Alenghat, Theresa; Mullican, Shannon E.; Jones, Steven; Rusche, James R.; Lazar, Mitchell A.; Wood, Marcelo A.

    2011-01-01

    Gene expression is dynamically regulated by chromatin modifications on histone tails, such as acetylation. In general, histone acetylation promotes transcription, whereas histone deacetylation negatively regulates transcription. The interplay between histone acetyl-transerases and histone deacetylases (HDACs) is pivotal for the regulation of gene expression required for long-term memory processes. Currently, very little is known about the role of individual HDACs in learning and memory. We examined the role of HDAC3 in long-term memory using a combined genetic and pharmacologic approach. We used HDAC3–FLOX genetically modified mice in combination with adeno-associated virus-expressing Cre recombinase to generate focal homozygous deletions of Hdac3 in area CA1 of the dorsal hippocampus. To complement this approach, we also used a selective inhibitor of HDAC3, RGFP136 [N-(6-(2-amino-4-fluorophenylamino)-6-oxohexyl)-4-methylbenzamide]. Immunohistochemistry showed that focal deletion or intrahippocampal delivery of RGFP136 resulted in increased histone acetylation. Both the focal deletion of HDAC3 as well as HDAC3 inhibition via RGFP136 significantly enhanced long-term memory in a persistent manner. Next we examined expression of genes implicated in long-term memory from dorsal hippocampal punches using quantitative reverse transcription-PCR. Expression of nuclear receptor subfamily 4 group A, member 2 (Nr4a2) and c-fos was significantly increased in the hippocampus of HDAC3–FLOX mice compared with wild-type controls. Memory enhancements observed in HDAC3–FLOX mice were abolished by intrahippocampal delivery of Nr4a2 small interfering RNA, suggesting a mechanism by which HDAC3 negatively regulates memory formation. Together, these findings demonstrate a critical role for HDAC3 in the molecular mechanisms underlying long-term memory formation. PMID:21228185

  14. Sumoylation of HDAC2 promotes NF-κB-dependent gene expression

    PubMed Central

    Wagner, Tobias; Kiweler, Nicole; Wolff, Katharina; Knauer, Shirley K.; Brandl, André; Hemmerich, Peter; Dannenberg, Jan-Hermen; Heinzel, Thorsten; Schneider, Günter; Krämer, Oliver H.

    2015-01-01

    The transcription factor nuclear factor-κB (NF-κB) is crucial for the maintenance of homeostasis. It is incompletely understood how nuclear NF-κB and the crosstalk of NF-κB with other transcription factors are controlled. Here, we demonstrate that the epigenetic regulator histone deacetylase 2 (HDAC2) activates NF-κB in transformed and primary cells. This function depends on both, the catalytic activity and an intact HDAC2 sumoylation motif. Several mechanisms account for the induction of NF-κB through HDAC2. The expression of wild-type HDAC2 can increase the nuclear presence of NF-κB. In addition, the ribosomal S6 kinase 1 (RSK1) and the tumor suppressor p53 contribute to the regulation of NF-κB by HDAC2. Moreover, TP53 mRNA expression is positively regulated by wild-type HDAC2 but not by sumoylation-deficient HDAC2. Thus, sumoylation of HDAC2 integrates NF-κB signaling involving p53 and RSK1. Since HDAC2-dependent NF-κB activity protects colon cancer cells from genotoxic stress, our data also suggest that high HDAC2 levels, which are frequently found in tumors, are linked to chemoresistance. Accordingly, inhibitors of NF-κB and of the NF-κB/p53-regulated anti-apoptotic protein survivin significantly sensitize colon carcinoma cells expressing wild-type HDAC2 to apoptosis induced by the genotoxin doxorubicin. Hence, the HDAC2-dependent signaling node we describe here may offer an interesting therapeutic option. PMID:25704882

  15. Class I HDACs Regulate Angiotensin II-Dependent Cardiac Fibrosis via Fibroblasts and Circulating Fibrocytes

    PubMed Central

    Williams, Sarah M.; Golden-Mason, Lucy; Ferguson, Bradley S.; Douglas, Katherine B.; Cavasin, Maria A.; Demos-Davies, Kim; Yeager, Michael E.; Stenmark, Kurt R.; McKinsey, Timothy A.

    2014-01-01

    Fibrosis, which is defined as excessive accumulation of fibrous connective tissue, contributes to the pathogenesis of numerous diseases involving diverse organ systems. Cardiac fibrosis predisposes individuals to myocardial ischemia, arrhythmias and sudden death, and is commonly associated with diastolic dysfunction. Histone deacetylase (HDAC) inhibitors block cardiac fibrosis in pre-clinical models of heart failure. However, which HDAC isoforms govern cardiac fibrosis, and the mechanisms by which they do so, remains unclear. Here, we show that selective inhibition of class I HDACs potently suppresses angiotensin II (Ang II)-mediated cardiac fibrosis by targeting two key effector cell populations, cardiac fibroblasts and bone marrow-derived fibrocytes. Class I HDAC inhibition blocks cardiac fibroblast cell cycle progression through derepression of the genes encoding the cyclin-dependent kinase (CDK) inhibitors, p15 and p57. In contrast, class I HDAC inhibitors block agonist-dependent differentiation of fibrocytes through a mechanism involving repression of ERK1/2 signaling. These findings define novel roles for class I HDACs in the control of pathological cardiac fibrosis. Furthermore, since fibrocytes have been implicated in the pathogenesis of a variety of human diseases, including heart, lung and kidney failure, our results suggest broad utility for isoform-selective HDAC inhibitors as anti-fibrotic agents that function, in part, by targeting these circulating mesenchymal cells. PMID:24374140

  16. The role of class I histone deacetylase (HDAC) on gluconeogenesis in liver

    SciTech Connect

    Oiso, Hiroshi; Furukawa, Noboru; Suefuji, Mihoshi; Shimoda, Seiya; Ito, Akihiro; Furumai, Ryohei; Nakagawa, Junichi; Yoshida, Minoru; Nishino, Norikazu; Araki, Eiichi

    2011-01-07

    Research highlights: {yields} A novel class I HDAC inhibitor decreased hepatic PEPCK mRNA and gluconeogenesis. {yields} Inhibition of HDAC decreased PEPCK by reducing HNF4{alpha} expression and FoxO1 activity. {yields} siRNA knockdown of HDAC1 in HepG2 cells reduced the expression of PEPCK and HNF4{alpha}. {yields} Inhibition of class I HDAC improves glucose homeostasis in HFD mice. -- Abstract: Hepatic gluconeogenesis is crucial for glucose homeostasis. Although sirtuin 1 (Sirt1) is implicated in the regulation of gluconeogenesis in the liver, the effects of other histone deacetylases (HDAC) on gluconeogenesis are unclear. The aim of this study was to identify the role of class I HDACs in hepatic gluconeogenesis. In HepG2 cells and the liver of mice, the expressions of phosphoenol pyruvate carboxykinase (PEPCK) and hepatocyte nuclear factor 4{alpha} (HNF4{alpha}) were significantly decreased by treatment with a newly designed class I HDAC inhibitor, Ky-2. SiRNA knockdown of HDAC1 expression, but not of HDAC2 or HDAC3, in HepG2 cells decreased PEPCK and HNF4{alpha} expression. In HepG2 cells, insulin-stimulated phosphorylation of Akt and forkhead box O 1 (FoxO1) was increased by Ky-2. Pyruvate tolerance tests in Ky-2-treated high-fat-diet (HFD)-fed mice showed a marked reduction in blood glucose compared with vehicle-treated HFD mice. These data suggest that class I HDACs increase HNF4{alpha} protein expression and the transcriptional activity of FoxO1, followed by the induction of PEPCK mRNA expression and gluconeogenesis in liver.

  17. Histone deacetylase inhibitors induce leukemia gene expression in cord blood hematopoietic stem cells expanded ex vivo.

    PubMed

    Lam, Yuk Man; Chan, Yuen Fan; Chan, Li Chong; Ng, Ray Kit

    2017-01-01

    Umbilical cord blood is a valuable source of hematopoietic stem cells. While cytokine stimulation can induce ex vivo hematopoietic cell proliferation, attempts have been made to use epigenetic-modifying agents to facilitate stem cell expansion through the modulation of cellular epigenetic status. However, the potential global effect of these modifying agents on epigenome raises concerns about the functional normality of the expanded cells. We studied the ex vivo expansion of cord blood hematopoietic stem and progenitor cells (HSPCs) by histone deacetylase (HDAC) inhibitors, trichostatin A and valproic acid. Treatment with HDAC inhibitors resulted in mild expansion of the total hematopoietic cell number when compared with cytokine stimulated sample. Nevertheless, we observed 20-30-fold expansion of the CD34(+) CD38(-) HSPC population. Strikingly, cord blood cells cultured with HDAC inhibitors exhibited aberrant expression of leukemia-associated genes, including CDKN1C, CEBPα, HOXA9, MN1, and DLK1. Our results thus suggest that the expansion of HSPCs by this approach may provoke a pre-leukemic cell state. We propose that the alteration of epigenome by HDAC inhibitors readily expands cord blood HSPC population through the re-activation of the leukemia gene transcription. The present study provides an assessment of the leukemogenic potential of HSCs expanded ex vivo using HDAC inhibitors for clinical applications.

  18. Expression-based screening identifies the combination of histone deacetylase inhibitors and retinoids for neuroblastoma differentiation

    PubMed Central

    Hahn, Cynthia K.; Ross, Kenneth N.; Warrington, Ian M.; Mazitschek, Ralph; Kanegai, Cindy M.; Wright, Renee D.; Kung, Andrew L.; Golub, Todd R.; Stegmaier, Kimberly

    2008-01-01

    The discovery of new small molecules and their testing in rational combination poses an ongoing problem for rare diseases, in particular, for pediatric cancers such as neuroblastoma. Despite maximal cytotoxic therapy with double autologous stem cell transplantation, outcome remains poor for children with high-stage disease. Because differentiation is aberrant in this malignancy, compounds that modulate transcription, such as histone deacetylase (HDAC) inhibitors, are of particular interest. However, as single agents, HDAC inhibitors have had limited efficacy. In the present study, we use an HDAC inhibitor as an enhancer to screen a small-molecule library for compounds inducing neuroblastoma maturation. To quantify differentiation, we use an enabling gene expression-based screening strategy. The top hit identified in the screen was all-trans-retinoic acid. Secondary assays confirmed greater neuroblastoma differentiation with the combination of an HDAC inhibitor and a retinoid versus either alone. Furthermore, effects of combination therapy were synergistic with respect to inhibition of cellular viability and induction of apoptosis. In a xenograft model of neuroblastoma, animals treated with combination therapy had the longest survival. This work suggests that testing of an HDAC inhibitor and retinoid in combination is warranted for children with neuroblastoma and demonstrates the success of a signature-based screening approach to prioritize compound combinations for testing in rare diseases. PMID:18607002

  19. Benzothiazole-containing hydroxamic acids as histone deacetylase inhibitors and antitumor agents.

    PubMed

    Oanh, Dao Thi Kim; Hai, Hoang Van; Park, Sang Ho; Kim, Hyun-Jung; Han, Byung-Woo; Kim, Hyung-Sook; Hong, Jin-Tae; Han, Sang-Bae; Hue, Van Thi My; Nam, Nguyen-Hai

    2011-12-15

    Data from clinical studies indicate that inhibitors of Class I and Class II histone deacetylase (HDAC) enzymes show great promise for the treatment of cancer. Zolinza (SAHA, Zolinza) was recently approved by the FDA for the treatment of the cutaneous manifestations of cutaneous T-cell lymphoma. As a part of our ongoing effort to identify novel small molecules to target these important enzymes, we have prepared two series of benzothiazole-containing analogues of SAHA. It was found that several compounds with 6C-bridge linking benzothiazole moiety and hydroxamic functional groups showed good inhibition against HDAC3 and 4 at as low as 1 μg/ml and exhibited potent cytotoxicity against five cancer cell lines with average IC(50) values of as low as 0.81 μg/ml, almost equipotent to SAHA.

  20. Research on the corrosion inhibitors of zinc in hydrochloric acid

    NASA Astrophysics Data System (ADS)

    Sun, C. X.; Chen, Y. M.; Xu, H. W.; Huang, C. S.; Zhang, M.; Wu, J. Y.; Chen, M.; Xue, M.

    2017-06-01

    Three organic compounds were tested as zinc corrosion inhibitors in hydrochloric acid: cetyltrimethyl ammonium bromide (CTAB), nicotini acid, bromohexadecyl pyridine. The static coupon test results indicate that CTAB and bromohexadecyl pyridine offer the best zinc corrosion protection, while nicotinic acid accelerates zinc corrosion. The polarization results indicate that CTAB, nicotinic acid and bromohexadecyl pyridine induce a positive shift in the E0 of zinc in hydrochloric acid. A complex of CTAB and bromohexadecyl pyridine inhibits the corrosion of zinc in hydrochloric acid. SEM results indicate that the CTAB and bromohexadecyl pyridine formed a uniform and compact membrane on the surface of zinc that subsequently protects the zinc from effective corrosion.

  1. Effect of inhibitors of arachidonic acid metabolism on alpha-aminoisobutyric acid transport in human lymphocytes.

    PubMed

    Udey, M C; Parker, C W

    1982-02-01

    The role of arachidonic acid metabolism (or metabolites) in the modulation of alpha-aminoisobutyric acid transport in resting and concanavalin A-stimulated human peripheral blood lymphocytes was evaluated using previously characterized inhibitors of arachidonic acid metabolism. Nordihydroguairetic acid (a nonselective antioxidant), 5,8,11,14-eicosatetraynoic acid (an inhibitor of lipoxygenase and cyclooxygenase activities), indomethacin and acetylsalicylic acid (selective cyclooxygenase inhibitors), and 1-benzylimidazole, Ro-22-3581 and Ro-22-3582 (thromboxane synthetase inhibitors) proved to be potent inhibitors of amino acid transport activity in normal resting and lectin-activated lymphocytes at concentrations known to decrease thromboxane A2 production. The rank order of effectiveness of these various inhibitors compared favorably with their relative potencies as inhibitors of thromboxane B2 synthesis under the same conditions, as determined by radioimmunoassay. Inhibitory effects noted were not due to overt cytotoxicity and seemed to involve changes primarily in the Vmax and not the Km of the transport process. Drug-induced alterations in the magnitude of concanavalin A binding were not observed. These results suggest that the activity of amino acid transport systems can be influenced by certain arachidonic acid metabolites, probably thromboxanes, in both stimulated and unstimulated lymphocytes. In addition, these findings may provide a partial explanation for the observation that inhibitors of thromboxane formation prevent lymphocyte mitogenesis.

  2. Uric acid urolithiasis and crystallization inhibitors.

    PubMed

    Grases, F; Ramis, M; Villacampa, A I; Costa-Bauzá, A

    1999-01-01

    An in vitro study of the inhibitory effects that some substances occasionally present in urine can provoke on the crystallization of uric acid has been performed. The most remarkable crystallization inhibitory effects were produced by mucine at concentrations of >0.5 mg/l. Pentosan polysulfate and chondroitin sulfate also clearly increased the uric acid crystallization times at concentrations of >100 mg/l. Saponins, such as escin and glycyrrhizic acid, also produced a notable delay in uric acid crystallization times at concentrations of >10 mg/l. Similar effects were observed in the presence of a surfactant substance, lauryl sulfate. N-Acetyl-L-cysteine caused crystallization perturbations only when it was present at concentrations of >50 mg/l. Citric acid and phytic acid caused no effects on uric acid crystallization even at the highest concentrations assayed (1,000 and 5 mg/l, respectively). From the results obtained it can be deduced that mainly glycoproteins, glycosaminoglycans and surfactant substances can exert protective effects against uric acid crystallization.

  3. Dual Inhibitors Against Topoisomerases and Histone Deacetylases

    PubMed Central

    Seo, Young Ho

    2015-01-01

    Topoisomerases and histone deacetylases (HDACs) are considered as important therapeutic targets for a wide range of cancers, due to their association with the initiation, proliferation and survival of cancer cells. Topoisomerases are involved in the cleavage and religation processes of DNA, while HDACs regulate a dynamic epigenetic modification of the lysine amino acid on various proteins. Extensive studies have been undertaken to discover small molecule inhibitor of each protein and thereby, several drugs have been transpired from this effort and successfully approved for clinical use. However, the inherent heterogeneity and multiple genetic abnormalities of cancers challenge the clinical application of these single targeted drugs. In order to overcome the limitations of a single target approach, a novel approach, simultaneously targeting topoisomerases and HDACs with a single molecule has been recently employed and attracted much attention of medicinal chemists in drug discovery. This review highlights the current studies on the discovery of dual inhibitors against topoisomerases and HDACs, provides their pharmacological aspects and advantages, and discusses the challenges and promise of the dual inhibitors. PMID:26151040

  4. Dual Inhibitors Against Topoisomerases and Histone Deacetylases.

    PubMed

    Seo, Young Ho

    2015-06-01

    Topoisomerases and histone deacetylases (HDACs) are considered as important therapeutic targets for a wide range of cancers, due to their association with the initiation, proliferation and survival of cancer cells. Topoisomerases are involved in the cleavage and religation processes of DNA, while HDACs regulate a dynamic epigenetic modification of the lysine amino acid on various proteins. Extensive studies have been undertaken to discover small molecule inhibitor of each protein and thereby, several drugs have been transpired from this effort and successfully approved for clinical use. However, the inherent heterogeneity and multiple genetic abnormalities of cancers challenge the clinical application of these single targeted drugs. In order to overcome the limitations of a single target approach, a novel approach, simultaneously targeting topoisomerases and HDACs with a single molecule has been recently employed and attracted much attention of medicinal chemists in drug discovery. This review highlights the current studies on the discovery of dual inhibitors against topoisomerases and HDACs, provides their pharmacological aspects and advantages, and discusses the challenges and promise of the dual inhibitors.

  5. HDAC3 mediates smoking-induced pancreatic cancer

    PubMed Central

    Edderkaoui, Mouad; Xu, Shiping; Chheda, Chintan; Morvaridi, Susan; Hu, Robert W.; Grippo, Paul J.; Mascariñas, Emman; Principe, Daniel R.; Knudsen, Beatrice; Xue, Jing; Habtezion, Aida; Uyeminami, Dale; Pinkerton, Kent E.; Pandol, Stephen J.

    2016-01-01

    Smoking is a major risk factor for developing pancreatic adenocarcinoma (PDAC); however, little is known about the mechanisms involved. Here we employed a genetic animal model of early stages of PDAC that overexpresses oncogenic Kras in the pancreas to investigate the mechanisms of smoking-induced promotion of the disease in vivo. We confirmed the regulation of the interactions between the tumor microenvironment cells using in vitro cellular systems. Aerial exposure to cigarette smoke stimulated development of pancreatic intraepithelial neaoplasia (PanIN) lesions associated with a tumor microenvironment-containing features of human PDAC including fibrosis, activated stellate cells, M2-macrophages and markers of epithelial-mesenchymal transition (EMT). The pro-cancer effects of smoking were prevented by Histone Deacetylase HDAC I/II inhibitor Saha. Smoking decreased histone acetylation associated with recruitment of and phenotypic changes in macrophages; which in turn, stimulated survival and induction of EMT of the pre-cancer and cancer cells. The interaction between the cancer cells and macrophages is mediated by IL-6 produced under the regulation of HDAC3 translocation to the nucleus in the cancer cells. Pharmacological and molecular inhibitions of HDAC3 decreased IL-6 levels in cancer cells. IL-6 stimulated the macrophage phenotype change through regulation of the IL-4 receptor level of the macrophage. This study demonstrates a novel pathway of interaction between cancer cells and tumor promoting macrophages involving HDAC3 and IL-6. It further demonstrates that targeting HDAC3 prevents progression of the disease and could provide a strategy for treating the disease considering that the HDAC inhibitor we used is FDA approved for a different disease. PMID:26745602

  6. The HDAC inhibitor FK228 enhances adenoviral transgene expression by a transduction-independent mechanism but does not increase adenovirus replication.

    PubMed

    Danielsson, Angelika; Dzojic, Helena; Rashkova, Victoria; Cheng, Wing-Shing; Essand, Magnus

    2011-02-17

    The histone deacetylase inhibitor FK228 has previously been shown to enhance adenoviral transgene expression when cells are pre-incubated with the drug. Upregulation of the coxsackie adenovirus receptor (CAR), leading to increased viral transduction, has been proposed as the main mechanism. In the present study, we found that the highest increase in transgene expression was achieved when non-toxic concentrations of FK228 were added immediately after transduction, demonstrating that the main effect by which FK228 enhances transgene expression is transduction-independent. FK228 had positive effects both on Ad5 and Ad5/f35 vectors with a variety of transgenes and promoters, indicating that FK228 works mainly by increasing transgene expression at the transcriptional level. In some cases, the effects were dramatic, as demonstrated by an increase in CD40L expression by FK228 from 0.3% to 62% when the murine prostate cancer cell line TRAMP-C2 was transduced with Ad[CD40L]. One unexpected finding was that FK228 decreased the transgene expression of an adenoviral vector with the prostate cell-specific PPT promoter in the human prostate adenocarcinoma cell lines LNCaP and PC-346C. This is probably a consequence of alteration of the adenocarcinoma cell lines towards a neuroendocrine differentiation after FK228 treatment. The observations in this study indicate that FK228 enhances adenoviral therapy by a transduction-independent mechanism. Furthermore, since histone deacetylase inhibitors may affect the differentiation of cells, it is important to keep in mind that the activity and specificity of tissue- and tumor-specific promoters may also be affected.

  7. The HDAC Inhibitor FK228 Enhances Adenoviral Transgene Expression by a Transduction-Independent Mechanism but Does Not Increase Adenovirus Replication

    PubMed Central

    Danielsson, Angelika; Dzojic, Helena; Rashkova, Victoria; Cheng, Wing-Shing; Essand, Magnus

    2011-01-01

    The histone deacetylase inhibitor FK228 has previously been shown to enhance adenoviral transgene expression when cells are pre-incubated with the drug. Upregulation of the coxsackie adenovirus receptor (CAR), leading to increased viral transduction, has been proposed as the main mechanism. In the present study, we found that the highest increase in transgene expression was achieved when non-toxic concentrations of FK228 were added immediately after transduction, demonstrating that the main effect by which FK228 enhances transgene expression is transduction-independent. FK228 had positive effects both on Ad5 and Ad5/f35 vectors with a variety of transgenes and promoters, indicating that FK228 works mainly by increasing transgene expression at the transcriptional level. In some cases, the effects were dramatic, as demonstrated by an increase in CD40L expression by FK228 from 0.3% to 62% when the murine prostate cancer cell line TRAMP-C2 was transduced with Ad[CD40L]. One unexpected finding was that FK228 decreased the transgene expression of an adenoviral vector with the prostate cell-specific PPT promoter in the human prostate adenocarcinoma cell lines LNCaP and PC-346C. This is probably a consequence of alteration of the adenocarcinoma cell lines towards a neuroendocrine differentiation after FK228 treatment. The observations in this study indicate that FK228 enhances adenoviral therapy by a transduction-independent mechanism. Furthermore, since histone deacetylase inhibitors may affect the differentiation of cells, it is important to keep in mind that the activity and specificity of tissue- and tumor-specific promoters may also be affected. PMID:21379379

  8. Neurorestoration induced by the HDAC inhibitor sodium valproate in the lactacystin model of Parkinson’s is associated with histone acetylation and up-regulation of neurotrophic factors

    PubMed Central

    Harrison, Ian F; Crum, William R; Vernon, Anthony C; Dexter, David T

    2015-01-01

    Background and Purpose Histone hypoacetylation is associated with Parkinson's disease (PD), due possibly to an imbalance in the activities of enzymes responsible for histone (de)acetylation; correction of which may be neuroprotective/neurorestorative. This hypothesis was tested using the anti-epileptic drug sodium valproate, a known histone deacetylase inhibitor (HDACI), utilizing a delayed-start study design in the lactacystin rat model of PD. Experimental Approach The irreversible proteasome inhibitor lactacystin was unilaterally injected into the substantia nigra of Sprague–Dawley rats that subsequently received valproate for 28 days starting 7 days after lactacystin lesioning. Longitudinal motor behavioural testing, structural MRI and post-mortem assessment of nigrostriatal integrity were used to track changes in this model of PD and quantify neuroprotection/restoration. Subsequent cellular and molecular analyses were performed to elucidate the mechanisms underlying valproate's effects. Key Results Despite producing a distinct pattern of structural re-modelling in the healthy and lactacystin-lesioned brain, delayed-start valproate administration induced dose-dependent neuroprotection/restoration against lactacystin neurotoxicity, characterized by motor deficit alleviation, attenuation of morphological brain changes and restoration of dopaminergic neurons in the substantia nigra. Molecular analyses revealed that valproate alleviated lactacystin-induced histone hypoacetylation and induced up-regulation of brain neurotrophic/neuroprotective factors. Conclusions and Implications The histone acetylation and up-regulation of neurotrophic/neuroprotective factors associated with valproate treatment culminate in a neuroprotective and neurorestorative phenotype in this animal model of PD. As valproate induced structural re-modelling of the brain, further research is required to determine whether valproate represents a viable candidate for disease treatment; however

  9. Inhibitors of Fatty Acid Synthase for Prostate Cancer

    DTIC Science & Technology

    2010-05-31

    targeting. Ursolic acid , a pentacyclic triterpenoid acid , as well as the tea polyphenols, epigallocatechin gallate (EGCG) and epicatechin gallate...2007,  6(7), 2120‐2126.  73.  Liu, Y., Tian, W., Ma, X., and Ding, W. Evaluation of  inhibition of  fatty  acid  synthase by  ursolic   acid : positive...AD_________________ Award Number: W81XWH-09-1-0204 TITLE: Inhibitors of Fatty Acid Synthase for

  10. Histone deacetylase inhibitors decrease Toll-like receptor-mediated activation of proinflammatory gene expression by impairing transcription factor recruitment

    PubMed Central

    Bode, Konrad A; Schroder, Kate; Hume, David A; Ravasi, Timothy; Heeg, Klaus; Sweet, Matthew J; Dalpke, Alexander H

    2007-01-01

    Post-translational modifications of histone proteins are major mechanisms that modify chromatin structure and regulate gene expression in eukaryotes. Activation of histone acetyltransferases or inhibition of histone deacetylases (HDACs) is generally believed to allow chromatin to assume a more open state, permitting transcriptional activity. We report here the surprising observation that treatment of murine dendritic cells with the HDAC inhibitors trichostatin A (TSA) or suberoylanilide hydroxamic acid (SAHA) in non-apoptotic concentrations strongly inhibited induction of both interleukin-12 protein p40 (IL-12p40) mRNA and protein upon stimulation of Toll-like receptors (TLRs). Moreover, TLR-mediated up-regulation of costimulatory molecules was also inhibited. Up-regulation of tumour necrosis factor-α mRNA and protein in response to TLR agonists was only affected upon prolonged exposure to HDAC inhibitors and regulation of IL-1β was not affected. Similar effects were apparent in murine and human macrophages. Regarding the mode of action, HDAC inhibition increased the acetylation status at the IL-12p40 locus. Nevertheless, IL-12p40 chromatin remodelling, binding of Rel-A and IRF1 to the IL-12p40 promoter and transcriptional activation were abrogated. In contrast, HDAC inhibitors had no effects on upstream nuclear factor-κB and mitogen-activated protein kinase activation. Thus HDACs positively regulate the expression of a subset of cytokine genes by enabling transcription factor recruitment. PMID:17635610

  11. Histone deacetylase inhibitors relieve morphine resistance in neuropathic pain after peripheral nerve injury.

    PubMed

    Uchida, Hitoshi; Matsushita, Yosuke; Araki, Kohei; Mukae, Takehiro; Ueda, Hiroshi

    2015-08-01

    Neuropathic pain is often insensitive to morphine. Our previous study has demonstrated that neuron-restrictive silencer factor represses mu opioid receptor (MOP) gene expression in the dorsal root ganglion (DRG) via histone hypoacetylation-mediated mechanisms after peripheral nerve injury, thereby causing loss of peripheral morphine analgesia. Here, we showed that histone deacetylase (HDAC) inhibitors, such as trichostatin A and valproic acid, restored peripheral and systemic morphine analgesia in neuropathic pain. Also, these agents blocked nerve injury-induced MOP down-regulation in the DRG. These results suggest that HDAC inhibitors could serve as adjuvant analgesics to morphine for the management of neuropathic pain.

  12. Inhibitors of Histone Deacetylases Attenuate Noise-Induced Hearing Loss.

    PubMed

    Chen, Jun; Hill, Kayla; Sha, Su-Hua

    2016-08-01

    Loss of auditory sensory hair cells is the major pathological feature of noise-induced hearing loss (NIHL). Currently, no established clinical therapies for prevention or amelioration of NIHL are available. The absence of treatments is due to our lack of a comprehensive understanding of the molecular mechanisms underlying noise-induced damage. Our previous study indicates that epigenetic modification of histones alters hair cell survival. In this study, we investigated the effect of noise exposure on histone H3 lysine 9 acetylation (H3K9ac) in the inner ear of adult CBA/J mice and determined if inhibition of histone deacetylases by systemic administration of suberoylanilide hydroxamic acid (SAHA) could attenuate NIHL. Our results showed that H3K9ac was decreased in the nuclei of outer hair cells (OHCs) and marginal cells of the stria vascularis in the basal region after exposure to a traumatic noise paradigm known to induce permanent threshold shifts (PTS). Consistent with these results, levels of histone deacetylases 1, 2, and 3 (HDAC1, HDAC2 and HDAC3) were increased predominately in the nuclei of cochlear cells. Silencing of HDAC1, HDAC2, or HDAC3 with siRNA reduced the expression of the target HDAC in OHCs, but did not attenuate noise-induced PTS, whereas treatment with the pan-HDAC inhibitor SAHA, also named vorinostat, reduced OHC loss, and attenuated PTS. These findings suggest that histone acetylation is involved in the pathogenesis of noise-induced OHC death and hearing loss. Pharmacological targeting of histone deacetylases may afford a strategy for protection against NIHL.

  13. HDAC1 activates FoxO and is both sufficient and required for skeletal muscle atrophy

    PubMed Central

    Beharry, Adam W.; Sandesara, Pooja B.; Roberts, Brandon M.; Ferreira, Leonardo F.; Senf, Sarah M.; Judge, Andrew R.

    2014-01-01

    ABSTRACT The Forkhead box O (FoxO) transcription factors are activated, and necessary for the muscle atrophy, in several pathophysiological conditions, including muscle disuse and cancer cachexia. However, the mechanisms that lead to FoxO activation are not well defined. Recent data from our laboratory and others indicate that the activity of FoxO is repressed under basal conditions via reversible lysine acetylation, which becomes compromised during catabolic conditions. Therefore, we aimed to determine how histone deacetylase (HDAC) proteins contribute to activation of FoxO and induction of the muscle atrophy program. Through the use of various pharmacological inhibitors to block HDAC activity, we demonstrate that class I HDACs are key regulators of FoxO and the muscle-atrophy program during both nutrient deprivation and skeletal muscle disuse. Furthermore, we demonstrate, through the use of wild-type and dominant-negative HDAC1 expression plasmids, that HDAC1 is sufficient to activate FoxO and induce muscle fiber atrophy in vivo and is necessary for the atrophy of muscle fibers that is associated with muscle disuse. The ability of HDAC1 to cause muscle atrophy required its deacetylase activity and was linked to the induction of several atrophy genes by HDAC1, including atrogin-1, which required deacetylation of FoxO3a. Moreover, pharmacological inhibition of class I HDACs during muscle disuse, using MS-275, significantly attenuated both disuse muscle fiber atrophy and contractile dysfunction. Together, these data solidify the importance of class I HDACs in the muscle atrophy program and indicate that class I HDAC inhibitors are feasible countermeasures to impede muscle atrophy and weakness. PMID:24463822

  14. Evaluation of benzoic acid derivatives as sirtuin inhibitors.

    PubMed

    Chen, Yi-Pei; Catbagan, Chad C; Bowler, Jeannette T; Gokey, Trevor; Goodwin, Natalie D M; Guliaev, Anton B; Wu, Weiming; Amagata, Taro

    2014-01-01

    Employing a genetically modified yeast strain as a screening tool, 4-dimethylaminobenzoic acid (5) was isolated from the marine sediment-derived Streptomyces sp. CP27-53 as a weak yeast sirtuin (Sir2p) inhibitor. Using this compound as a scaffold, a series of disubstituted benzene derivatives were evaluated to elucidate the structure activity relationships for Sir2p inhibition. The results suggested that 4-alkyl or 4-alkylaminobenzoic acid is the key structure motif for Sir2p inhibitory activity. The most potent Sir2p inhibitor, 4-tert-butylbenzoic acid (20), among the tested compounds in this study turned out to be a weak but selective SIRT1 inhibitor. The calculated binding free energies between the selected compounds and the catalytic domain of SIRT1 were well correlated to their measured SIRT1 inhibitory activities.

  15. The Histone Deacetylase Inhibitor Vaproic Acid Induces Cell Growth Arrest in Hepatocellular Carcinoma Cells via Suppressing Notch Signaling

    PubMed Central

    Sun, Guangchun; Mackey, Lily V.; Coy, David H.; Yu, Cui-Yun; Sun, Lichun

    2015-01-01

    Hepatocellular carcinoma (HCC) is a type of malignant cancer. Notch signaling is aberrantly expressed in HCC tissues with more evidence showing that this signaling plays a critical role in HCCs. In the present study, we investigate the effects of the anti-convulsant drug valproic acid (VPA) in HCC cells and its involvement in modulating Notch signaling. We found that VPA, acting as a histone deacetylase (HDAC) inhibitor, induced a decrease in HDAC4 and an increase in acetylated histone 4 (AcH4) and suppressed HCC cell growth. VPA also induced down-regulation of Notch signaling via suppressing the expression of Notch1 and its target gene HES1, with an increase of tumor suppressor p21 and p63. Furthermore, Notch1 activation via overexpressing Notch1 active form ICN1 induced HCC cell proliferation and anti-apoptosis, indicating Notch signaling played an oncogenic role in HCC cells. Meanwhile, VPA could reverse Notch1-induced increase of cell proliferation. Interestingly, VPA was also observed to stimulate the expression of G protein-coupled somatostatin receptor type 2 (SSTR2) that has been used in receptor-targeting therapies. This discovery supports a combination therapy of VPA with the SSTR2-targeting agents. Our in vitro assay did show that the combination of VPA and the peptide-drug conjugate camptothecin-somatostatin (CPT-SST) displayed more potent anti-proliferative effects on HCC cells than did each alone. VPA may be a potential drug candidate in the development of anti-HCC drugs via targeting Notch signaling, especially in combination with receptor-targeting cytotoxic agents. PMID:26366213

  16. Identification of sulfonic acids as efficient ecto-5'-nucleotidase inhibitors.

    PubMed

    Iqbal, Jamshed; Saeed, Aamer; Raza, Rabia; Matin, Abdul; Hameed, Abdul; Furtmann, Norbert; Lecka, Joanna; Sévigny, Jean; Bajorath, Jürgen

    2013-01-01

    Ecto-5'-nucleotidase (CD73) is well known for its implication in cancer. Inhibition of ecto-5'-nucleotidases is thought to provide an attractive approach to cancer therapy. This study identifies sulfonic acid compounds as efficient inhibitors of ecto-5'-nucleotidases. The compounds were tested against recombinant human and rat ecto-5'-nucleotidases. The most potent new sulfonic acid inhibitor 6-amino-4-hydroxynaphthalene-2-sulfonic acid (1) of ecto-5'-nucleotidase had an IC₅₀ of 1.32 ± 0.09 μM for the human and 10.4 ± 3.3 μM for the rat enzyme. Generally, all compounds were more active against the human enzyme. Plausible binding mode models were developed for this new class of inhibitors. Furthermore, several sulfonic acid inhibitors were efficient cytotoxic agents when tested on H157 cancer cell lines. Hence, new ecto-5'-nucleotidases inhibitors displayed significant potential for further development as compounds for anti-cancer therapy.

  17. A phase 1 trial of the HDAC inhibitor AR-42 in patients with multiple myeloma and T- and B-cell lymphomas.

    PubMed

    Sborov, Douglas W; Canella, Alessandro; Hade, Erinn M; Mo, Xiaokui; Khountham, Soun; Wang, Jiang; Ni, Wenjun; Poi, Ming; Coss, Christopher; Liu, Zhongfa; Phelps, Mitch A; Mortazavi, Amir; Andritsos, Leslie; Baiocchi, Robert A; Christian, Beth A; Benson, Don M; Flynn, Joseph; Porcu, Pierluigi; Byrd, John C; Pichiorri, Flavia; Hofmeister, Craig C

    2017-10-01

    Histone deacetylase inhibitors (HDACi) have proven activity in hematologic malignancies, and their FDA approval in multiple myeloma (MM) and T-cell lymphoma highlights the need for further development of this drug class. We investigated AR-42, an oral pan-HDACi, in a first-in-man phase 1 dose escalation clinical trial. Overall, treatment was well tolerated, no DLTs were evident, and the MTD was defined as 40 mg dosed three times weekly for three weeks of a 28-day cycle. One patient each with MM and mantle cell lymphoma demonstrated disease control for 19 and 27 months (ongoing), respectively. Treatment was associated with reduction of serum CD44, a transmembrane glycoprotein associated with steroid and immunomodulatory drug resistance in MM. Our findings indicate that AR-42 is safe and that further investigation of AR-42 in combination regimens for the treatment of patients with lymphoma and MM is warranted. http://clinicaltrials.gov/ct2/show/NCT01129193.

  18. HDAC2 deregulation in tumorigenesis is causally connected to repression of immune modulation and defense escape

    PubMed Central

    Conte, Mariarosaria; Dell'Aversana, Carmela; Benedetti, Rosaria; Petraglia, Francesca; Carissimo, Annamaria; Petrizzi, Valeria Belsito; D'Arco, Alfonso Maria; Abbondanza, Ciro; Nebbioso, Angela; Altucci, Lucia

    2015-01-01

    Histone deacetylase 2 (HDAC2) is overexpressed or mutated in several disorders such as hematological cancers, and plays a critical role in transcriptional regulation, cell cycle progression and developmental processes. Here, we performed comparative transcriptome analyses in acute myeloid leukemia to investigate the biological implications of HDAC2 silencing versus its enzymatic inhibition using epigenetic-based drug(s). By gene expression analysis of HDAC2-silenced vs wild-type cells, we found that HDAC2 has a specific role in leukemogenesis. Gene expression profiling of U937 cell line with or without treatment of the well-known HDAC inhibitor vorinostat (SAHA) identifies and characterizes several gene clusters where inhibition of HDAC2 ‘mimics’ its silencing, as well as those where HDAC2 is selectively and exclusively regulated by HDAC2 protein expression levels. These findings may represent an important tool for better understanding the mechanisms underpinning immune regulation, particularly in the study of major histocompatibility complex class II genes. PMID:25473896

  19. A novel histone deacetylase 1 and 2 isoform-specific inhibitor alleviates experimental Parkinson's disease.

    PubMed

    Choong, Chi-Jing; Sasaki, Tsutomu; Hayakawa, Hideki; Yasuda, Toru; Baba, Kousuke; Hirata, Yoshiyuki; Uesato, Shinichi; Mochizuki, Hideki

    2016-01-01

    With increased histone deacetylase (HDAC) activity and histone hypoacetylation being implicated in neurodegeneration, HDAC inhibitors have been reported to have considerable therapeutic potential. Yet, existing inhibitors lack specificity and may show substantial adverse effect. In this study, we identified a novel HDAC1/2 isoform-specific inhibitor, K560, with protective effects against 1-methyl-4-phenylpyridinium (MPP(+))- and/or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neuronal death in both in vitro and in vivo Parkinson's disease model. K560 attenuated cell death induced by MPP(+) in differentiated SH-SY5Y cells through the sustained expression of an antiapoptotic protein, X-linked inhibitor of apoptosis (XIAP). Inhibition of XIAP expression by locked nucleic acid antisense oligonucleotides abolished the protective effect of K560. Inactivation of mitogen-activated protein kinase cascades, reduced p53 phosphorylation, and down-regulation of p53-upregulated modulator of apoptosis on K560 treatment were also observed. Furthermore, pre- and post-oral administration of K560 to mice prevented MPTP-induced loss of dopaminergic neurons in substantia nigra, suggesting that selective inhibition of HDAC1 and HDAC2 by K560 may pave the way to new strategies for Parkinson's disease treatment.

  20. Ex Vivo Response to Histone Deacetylase (HDAC) Inhibitors of the HIV Long Terminal Repeat (LTR) Derived from HIV-Infected Patients on Antiretroviral Therapy

    PubMed Central

    Lu, Hao K.; Gray, Lachlan R.; Wightman, Fiona; Ellenberg, Paula; Khoury, Gabriela; Cheng, Wan-Jung; Mota, Talia M.; Wesselingh, Steve; Gorry, Paul R.; Cameron, Paul U.

    2014-01-01

    Histone deacetylase inhibitors (HDACi) can induce human immunodeficiency virus (HIV) transcription from the HIV long terminal repeat (LTR). However, ex vivo and in vivo responses to HDACi are variable and the activity of HDACi in cells other than T-cells have not been well characterised. Here, we developed a novel assay to determine the activity of HDACi on patient-derived HIV LTRs in different cell types. HIV LTRs from integrated virus were amplified using triple-nested Alu-PCR from total memory CD4+ T-cells (CD45RO+) isolated from HIV-infected patients prior to and following suppressive antiretroviral therapy. NL4-3 or patient-derived HIV LTRs were cloned into the chromatin forming episomal vector pCEP4, and the effect of HDACi investigated in the astrocyte and epithelial cell lines SVG and HeLa, respectively. There were no significant differences in the sequence of the HIV LTRs isolated from CD4+ T-cells prior to and after 18 months of combination antiretroviral therapy (cART). We found that in both cell lines, the HDACi panobinostat, trichostatin A, vorinostat and entinostat activated patient-derived HIV LTRs to similar levels seen with NL4-3 and all patient derived isolates had similar sensitivity to maximum HDACi stimulation. We observed a marked difference in the maximum fold induction of luciferase by HDACi in HeLa and SVG, suggesting that the effect of HDACi may be influenced by the cellular environment. Finally, we observed significant synergy in activation of the LTR with vorinostat and the viral protein Tat. Together, our results suggest that the LTR sequence of integrated virus is not a major determinant of a functional response to an HDACi. PMID:25409334

  1. Docking ligands into flexible and solvated macromolecules. 6. Development and application to the docking of HDACs and other zinc metalloenzymes inhibitors.

    PubMed

    Pottel, Joshua; Therrien, Eric; Gleason, James L; Moitessier, Nicolas

    2014-01-27

    Metalloenzymes are ubiquitous proteins which feature one or more metal ions either directly involved in the enzymatic activity and/or structural properties (i.e., zinc fingers). Several members of this class take advantage of the Lewis acidic properties of zinc ions to carry out their various catalytic transformations including isomerization or amide cleavage. These enzymes have been validated as drug targets for a number of diseases including cancer; however, despite their pharmaceutical relevance and the availability of crystal structures, structure-based drug design methods have been poorly and indirectly parametrized for these classes of enzymes. More specifically, the metal coordination component and proton transfers of the process of drugs binding to metalloenzymes have been inadequately modeled by current docking programs, if at all. In addition, several known issues, such as coordination geometry, atomic charge variability, and a potential proton transfer from small molecules to a neighboring basic residue, have often been ignored. We report herein the development of specific functions and parameters to account for zinc-drug coordination focusing on the above-listed phenomena and their impact on docking to zinc metalloenzymes. These atom-type-dependent but atomic charge-independent functions implemented into Fitted 3.1 enable the simulation of drug binding to metalloenzymes, considering an acid-base reaction with a neighboring residue when necessary with good accuracy.

  2. Searching the conformational complexity and binding properties of HDAC6 through docking and molecular dynamic simulations.

    PubMed

    Sixto-López, Yudibeth; Bello, Martiniano; Rodríguez-Fonseca, Rolando Alberto; Rosales-Hernández, Martha Cecilia; Martínez-Archundia, Marlet; Gómez-Vidal, José Antonio; Correa-Basurto, José

    2016-09-23

    Histone deacetylases (HDACs) are a family of proteins involved in the deacetylation of histones and other non-histones substrates. HDAC6 belongs to class II and shares similar biological functions with others of its class. Nevertheless, its three-dimensional structure that involves the catalytic site remains unknown for exploring the ligand recognition properties. Therefore, in this contribution, homology modeling, 100-ns-long Molecular Dynamics (MD) simulation and docking calculations were combined to explore the conformational complexity and binding properties of the catalytic domain 2 from HDAC6 (DD2-HDAC6), for which activity and affinity toward five different ligands have been reported. Clustering analysis allowed identifying the most populated conformers present during the MD simulation, which were used as starting models to perform docking calculations with five DD2-HDAC6 inhibitors: Cay10603 (CAY), Rocilinostat (RCT), Tubastatin A (TBA), Tubacin (TBC), and Nexturastat (NXT), and then were also submitted to 100-ns-long MD simulations. Docking calculations revealed that the five inhibitors bind at the DD2-HDAC6 binding site with the lowest binding free energy, the same binding mode is maintained along the 100-ns-long MD simulations. Overall, our results provide structural information about the molecular flexibility of apo and holo DD2-HDAC6 states as well as insight of the map of interactions between DD2-HDAC6 and five well-known DD2-HDAC6 inhibitors allowing structural details to guide the drug design. Finally, we highlight the importance of combining different theoretical approaches to provide suitable structural models for structure-based drug design.

  3. MDM2 E3 ligase-mediated ubiquitination and degradation of HDAC1 in vascular calcification

    PubMed Central

    Kwon, Duk-Hwa; Eom, Gwang Hyeon; Ko, Jeong Hyeon; Shin, Sera; Joung, Hosouk; Choe, Nakwon; Nam, Yoon Seok; Min, Hyun-Ki; Kook, Taewon; Yoon, Somy; Kang, Wanseok; Kim, Yong Sook; Kim, Hyung Seok; Choi, Hyuck; Koh, Jeong-Tae; Kim, Nacksung; Ahn, Youngkeun; Cho, Hyun-Jai; Lee, In-Kyu; Park, Dong Ho; Suk, Kyoungho; Seo, Sang Beom; Wissing, Erin R.; Mendrysa, Susan M.; Nam, Kwang-Il; Kook, Hyun

    2016-01-01

    Vascular calcification (VC) is often associated with cardiovascular and metabolic diseases. However, the molecular mechanisms linking VC to these diseases have yet to be elucidated. Here we report that MDM2-induced ubiquitination of histone deacetylase 1 (HDAC1) mediates VC. Loss of HDAC1 activity via either chemical inhibitor or genetic ablation enhances VC. HDAC1 protein, but not mRNA, is reduced in cell and animal calcification models and in human calcified coronary artery. Under calcification-inducing conditions, proteasomal degradation of HDAC1 precedes VC and it is mediated by MDM2 E3 ubiquitin ligase that initiates HDAC1 K74 ubiquitination. Overexpression of MDM2 enhances VC, whereas loss of MDM2 blunts it. Decoy peptide spanning HDAC1 K74 and RG 7112, an MDM2 inhibitor, prevent VC in vivo and in vitro. These results uncover a previously unappreciated ubiquitination pathway and suggest MDM2-mediated HDAC1 ubiquitination as a new therapeutic target in VC. PMID:26832969

  4. Radio-sensitizing Effects of Novel Histone De-Acetylase Inhibitors in Prostate Cancer

    DTIC Science & Technology

    2007-03-01

    Two of these inhibitors (VAD-18 and VAD-20) having phenylacetic acid and butyric acid respectively as the lead compound (Fig. 1) have been used in the...combination with radiation to augment clinical efficacy and/or to reduce toxicity. The HDAC inhibitors- phenyl butyrate (40), sodium butyrate (41...cancer cell lines. However, since sodium butyrate and trichostatin A have limitations as mentioned above and in addition the mechanisms of radio

  5. HDAC7 Ubiquitination by the E3 Ligase CBX4 Is Involved in Contextual Fear Conditioning Memory Formation.

    PubMed

    Jing, Xu; Sui, Wen-Hai; Wang, Shuai; Xu, Xu-Feng; Yuan, Rong-Rong; Chen, Xiao-Rong; Ma, Hui-Xian; Zhu, Ying-Xiao; Sun, Jin-Kai; Yi, Fan; Chen, Zhe-Yu; Wang, Yue

    2017-04-05

    Histone acetylation, an epigenetic modification, plays an important role in long-term memory formation. Recently, histone deacetylase (HDAC) inhibitors were demonstrated to promote memory formation, which raises the intriguing possibility that they may be used to rescue memory deficits. However, additional research is necessary to clarify the roles of individual HDACs in memory. In this study, we demonstrated that HDAC7, within the dorsal hippocampus of C57BL6J mice, had a late and persistent decrease after contextual fear conditioning (CFC) training (4-24 h), which was involved in long-term CFC memory formation. We also showed that HDAC7 decreased via ubiquitin-dependent degradation. CBX4 was one of the HDAC7 E3 ligases involved in this process. Nur77, as one of the target genes of HDAC7, increased 6-24 h after CFC training and, accordingly, modulated the formation of CFC memory. Finally, HDAC7 was involved in the formation of other hippocampal-dependent memories, including the Morris water maze and object location test. The current findings facilitate an understanding of the molecular and cellular mechanisms of HDAC7 in the regulation of hippocampal-dependent memory.SIGNIFICANCE STATEMENT The current findings demonstrated the effects of histone deacetylase 7 (HDAC7) on hippocampal-dependent memories. Moreover, we determined the mechanism of decreased HDAC7 in contextual fear conditioning (CFC) through ubiquitin-dependent protein degradation. We also verified that CBX4 was one of the HDAC7 E3 ligases. Finally, we demonstrated that Nur77, as one of the important targets for HDAC7, was involved in CFC memory formation. All of these proteins, including HDAC7, CBX4, and Nur77, could be potential therapeutic targets for preventing memory deficits in aging and neurological diseases.

  6. Inhibition of Histone Deacetylase 3 (HDAC3) Mediates Ischemic Preconditioning and Protects Cortical Neurons against Ischemia in Rats

    PubMed Central

    Wu, Qimei; Zhang, Lei; Feng, Linyin

    2016-01-01

    Brain ischemic preconditioning (PC) provides vital insights into the endogenous protection against stroke. Genomic and epigenetic responses to PC condition the brain into a state of ischemic tolerance. Notably, PC induces the elevation of histone acetylation, consistent with evidence that histone deacetylase (HDAC) inhibitors protect the brain from ischemic injury. However, less is known about the specific roles of HDACs in this process. HDAC3 has been implicated in several neurodegenerative conditions. Deletion of HDAC3 confers protection against neurotoxicity and neuronal injury. Here, we hypothesized that inhibition of HDAC3 may contribute to the neuronal survival elicited by PC. To address this notion, PC and transient middle cerebral artery occlusion (MCAO) were conducted in Sprague-Dawley rats. Additionally, primary cultured cortical neurons were used to identify the modulators and effectors of HDAC3 involved in PC. We found that nuclear localization of HDAC3 was significantly reduced following PC in vivo and in vitro. Treatment with the HDAC3-specific inhibitor, RGFP966, mimicked the neuroprotective effects of PC 24 h and 7 days after MCAO, causing a reduced infarct volume and less Fluoro-Jade C staining. Improved functional outcomes were observed in the neurological score and rotarod test. We further showed that attenuated recruitment of HDAC3 to promoter regions following PC potentiates transcriptional initiation of genes including Hspa1a, Bcl2l1, and Prdx2, which may underlie the mechanism of protection. In addition, PC-activated calpains were implicated in the cleavage of HDAC3. Pretreatment with calpeptin blockaded the attenuated nuclear distribution of HDAC3 and the protective effect of PC in vivo. Collectively, these results demonstrate that the inhibition of HDAC3 preconditions the brain against ischemic insults, indicating a new approach to evoke endogenous protection against stroke. PMID:27965534

  7. Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

    SciTech Connect

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena . E-mail: elena.menegola@unimi.it

    2007-04-15

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor {alpha} = 0.51 and maximum velocity by a factor {beta} = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations.

  8. Boric acid inhibits embryonic histone deacetylases: a suggested mechanism to explain boric acid-related teratogenicity.

    PubMed

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L; Giavini, Erminio; Menegola, Elena

    2007-04-15

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor alpha=0.51 and maximum velocity by a factor beta=0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations.

  9. Mechanism for neurotropic action of vorinostat, a pan histone deacetylase inhibitor

    USDA-ARS?s Scientific Manuscript database

    In this study we investigated the effect of vorinostat (suberanilohydroxamic acid, SAHA), a class I and class II HDAC inhibitor, on the differentiation of Neuroscreen-1 (NS-1) cells. NS-1 cell is a subclone of the rat pheochromocytoma cell line (PC 12). PC12 cells on treatment with nerve growth fac...

  10. Valproic acid prevents penile fibrosis and erectile dysfunction in cavernous nerve-injured rats.

    PubMed

    Hannan, Johanna L; Kutlu, Omer; Stopak, Bernard L; Liu, Xiaopu; Castiglione, Fabio; Hedlund, Petter; Burnett, Arthur L; Bivalacqua, Trinity J

    2014-06-01

    Bilateral cavernous nerve injury (BCNI) causes profound penile changes such as apoptosis and fibrosis leading to erectile dysfunction (ED). Histone deacetylase (HDAC) has been implicated in chronic fibrotic diseases. This study will characterize the molecular changes in penile HDAC after BCNI and determine if HDAC inhibition can prevent BCNI-induced ED and penile fibrosis. Five groups of rats (8-10 weeks, n = 10/group) were utilized: (i) sham; (ii and iii) BCNI 14 and 30 days following injury; and (iv and v) BCNI treated with HDAC inhibitor valproic acid (VPA 250 mg/kg; 14 and 30 days). All groups underwent cavernous nerve stimulation (CNS) to determine intracavernosal pressure (ICP). Penile HDAC3, HDAC4, fibronectin, and transforming growth factor-β1 (TGF-β1) protein expression (Western blot) were assessed. Trichrome staining and the fractional area of fibrosis were determined in penes from each group. Cavernous smooth muscle content was assessed by immunofluorescence to alpha smooth muscle actin (α-SMA) antibodies. We measured ICP; HDAC3, HDAC4, fibronectin, and TGF-β1 protein expression; penile fibrosis; penile α-SMA content. There was a voltage-dependent decline (P < 0.05) in ICP to CNS 14 and 30 days after BCNI. Penile HDAC3, HDAC4, and fibronectin were significantly increased (P < 0.05) 14 days after BCNI. There was a slight increase in TGF-β1 protein expression after BCNI. Histological analysis showed increased (P < 0.05) corporal fibrosis after BCNI at both time points. VPA treatment decreased (P < 0.05) penile HDAC3, HDAC4, and fibronectin protein expression as well as corporal fibrosis. There was no change in penile α-SMA between all groups. Furthermore, VPA-treated BCNI rats had improved erectile responses to CNS (P < 0.05). HDAC-induced pathological signaling in response to BCNI contributes to penile vascular dysfunction. Pharmacological inhibition of HDAC prevents penile fibrosis, normalizes fibronectin expression, and

  11. Polyamines are Inhibitors of Gastric Acid Secretion

    NASA Astrophysics Data System (ADS)

    Ray, Tushar K.; Nandi, Jyotirmoy; Pidhorodeckyj, Nykolai; Meng-Ai, Zhou

    1982-03-01

    The naturally occurring organic polycations such as spermine and spermidine inhibit histamine-stimulated gastric acid secretion by bullfrog gastric mucosa in vitro; spermine is much more potent than spermidine. Unlike the H2 receptor antagonists, the polyamines are completely ineffective from the nutrient side and are effective only from the secretory side of the chambered mucosa. The polyamine effects could be reversed by increasing K+ concentration in the secretory solution. Studies with isolated gastric microsomal vesicles demonstrate that the polyamines do not inhibit the gastric H+,K+-ATPase but greatly decrease the ATPase-mediated uptake of H+ under appropriate conditions. For the latter effects the presence of polyamine within the vesicle interior was found to be essential. Our data strongly suggest an uncoupling of the gastric H+,K+-ATPase system by the polyamines. The therapeutic potential of these and similar compounds in the treatment of hyperacidity and peptic ulcer is discussed.

  12. Conservative and nonconservative inhibitors of gastric acid secretion

    SciTech Connect

    Ekblad, E.B.M.; Licko, V.

    1987-09-01

    Inhibitors of the initial step (H/sub 2/-antagonist) and of the final step (thiocyanate, SCN/sup -/; and nitrite, NO/sub 2//sup -/) were used to study the dynamics of acid secretion in isolated frog gastric mucosa. Tissues were mounted in flow-through chambers, and the acid secretion rate (SR) was recorded on a pH-stat microprocessor. Continuous presence of H/sub 2/-antagonist decreases the SR to a lower steady state, and on removal the SR returns to basal SR, causing a net loss of acid, the nonconservative effect. The amount of lost acid is a unique function of exposure, thus, independent of the patterns (pulses or steps) of inhibition. In contrast, continuous presence of SCN/sup -/ or NO/sub 2//sup -/ (below 3 mM) results in an undershoot in SR with a return to basal SR, whereas at higher concentrations there is not return. Removal of these inhibitors causes an overshoot in SR with return to basal SR. The rebound acid is equal to acid suppressed by NO/sub 2//sup -/ and low concentration of SCN/sup -/, resulting in no net loss of acid, the conservative effect, whereas at high concentrations of SCN/sup -/ there is an apparent loss of acid. In maximally secreting tissue the overshoot of SR is not observed. However, the acid is not lost, merely delayed. In resting tissue NO/sub 2//sup -/ also merely delays the exit of the acid produced in response to forskolin. The rebound acid is proposed to reside in a sequestered acid pool that is stable for at least 120 min. Results with NO/sub 2//sup -/ and SCN/sup -/ suggest an effect on a saturable exit enzyme, possibly the K/sup +/-H/sup +/-ATPase.

  13. Chemical origins of isoform selectivity in histone deacetylase inhibitors.

    PubMed

    Butler, Kyle V; Kozikowski, Alan P

    2008-01-01

    Histones undergo extensive posttranslational modifications that affect gene expression. Acetylation is a key histone modification that is primarily regulated by two enzymes, one of which is histone deacetylase (HDAC). The activity of HDAC causes transcriptional silencing of DNA. Eleven distinct zinc-dependent histone deacetylase isoforms have been identified in humans. Each isoform has a unique structure and function, and regulates a unique set of genes. HDAC is responsible for the regulation of many genes involved in cancer cell proliferation, and it has been implicated in the pathogenesis of many neurological conditions. HDAC inhibitors are known to be very effective anti-cancer agents, and research has shown them to be potential treatments for many other conditions. Histone deacetylase inhibitors modify the expression of many genes, and it is possible that inhibition of one isoform could cause epigenetic changes that are beneficial to treatment of a disease, while inhibition of another isoform could cause contradictory changes. Selective HDAC inhibitors will be better able to avoid these types of situations than non-specific inhibitors, and may also be less toxic than pan-HDAC inhibitors. Many potent pan-HDAC inhibitors have already been developed, leaving the development of selective inhibitors at the forefront of HDAC drug development. Certain structural moieties may be added to HDAC inhibitors to give isoform selectivity, and these will be discussed in this review. This review will focus on the applications of selective HDAC inhibitors, inhibitors reported to show selectivity, and the relationship between inhibitor structure and selectivity.

  14. Structural basis for the inhibition of histone deacetylase 8 (HDAC8), a key epigenetic player in the blood fluke Schistosoma mansoni.

    PubMed

    Marek, Martin; Kannan, Srinivasaraghavan; Hauser, Alexander-Thomas; Moraes Mourão, Marina; Caby, Stéphanie; Cura, Vincent; Stolfa, Diana A; Schmidtkunz, Karin; Lancelot, Julien; Andrade, Luiza; Renaud, Jean-Paul; Oliveira, Guilherme; Sippl, Wolfgang; Jung, Manfred; Cavarelli, Jean; Pierce, Raymond J; Romier, Christophe

    2013-01-01

    The treatment of schistosomiasis, a disease caused by blood flukes parasites of the Schistosoma genus, depends on the intensive use of a single drug, praziquantel, which increases the likelihood of the development of drug-resistant parasite strains and renders the search for new drugs a strategic priority. Currently, inhibitors of human epigenetic enzymes are actively investigated as novel anti-cancer drugs and have the potential to be used as new anti-parasitic agents. Here, we report that Schistosoma mansoni histone deacetylase 8 (smHDAC8), the most expressed class I HDAC isotype in this organism, is a functional acetyl-L-lysine deacetylase that plays an important role in parasite infectivity. The crystal structure of smHDAC8 shows that this enzyme adopts a canonical α/β HDAC fold, with specific solvent exposed loops corresponding to insertions in the schistosome HDAC8 sequence. Importantly, structures of smHDAC8 in complex with generic HDAC inhibitors revealed specific structural changes in the smHDAC8 active site that cannot be accommodated by human HDACs. Using a structure-based approach, we identified several small-molecule inhibitors that build on these specificities. These molecules exhibit an inhibitory effect on smHDAC8 but show reduced affinity for human HDACs. Crucially, we show that a newly identified smHDAC8 inhibitor has the capacity to induce apoptosis and mortality in schistosomes. Taken together, our biological and structural findings define the framework for the rational design of small-molecule inhibitors specifically interfering with schistosome epigenetic mechanisms, and further support an anti-parasitic epigenome targeting strategy to treat neglected diseases caused by eukaryotic pathogens.

  15. Structural Basis for the Inhibition of Histone Deacetylase 8 (HDAC8), a Key Epigenetic Player in the Blood Fluke Schistosoma mansoni

    PubMed Central

    Marek, Martin; Kannan, Srinivasaraghavan; Hauser, Alexander-Thomas; Moraes Mourão, Marina; Caby, Stéphanie; Cura, Vincent; Stolfa, Diana A.; Schmidtkunz, Karin; Lancelot, Julien; Andrade, Luiza; Renaud, Jean-Paul; Oliveira, Guilherme; Sippl, Wolfgang; Jung, Manfred; Cavarelli, Jean; Pierce, Raymond J.; Romier, Christophe

    2013-01-01

    The treatment of schistosomiasis, a disease caused by blood flukes parasites of the Schistosoma genus, depends on the intensive use of a single drug, praziquantel, which increases the likelihood of the development of drug-resistant parasite strains and renders the search for new drugs a strategic priority. Currently, inhibitors of human epigenetic enzymes are actively investigated as novel anti-cancer drugs and have the potential to be used as new anti-parasitic agents. Here, we report that Schistosoma mansoni histone deacetylase 8 (smHDAC8), the most expressed class I HDAC isotype in this organism, is a functional acetyl-L-lysine deacetylase that plays an important role in parasite infectivity. The crystal structure of smHDAC8 shows that this enzyme adopts a canonical α/β HDAC fold, with specific solvent exposed loops corresponding to insertions in the schistosome HDAC8 sequence. Importantly, structures of smHDAC8 in complex with generic HDAC inhibitors revealed specific structural changes in the smHDAC8 active site that cannot be accommodated by human HDACs. Using a structure-based approach, we identified several small-molecule inhibitors that build on these specificities. These molecules exhibit an inhibitory effect on smHDAC8 but show reduced affinity for human HDACs. Crucially, we show that a newly identified smHDAC8 inhibitor has the capacity to induce apoptosis and mortality in schistosomes. Taken together, our biological and structural findings define the framework for the rational design of small-molecule inhibitors specifically interfering with schistosome epigenetic mechanisms, and further support an anti-parasitic epigenome targeting strategy to treat neglected diseases caused by eukaryotic pathogens. PMID:24086136

  16. Divergent roles of HDAC1 and HDAC2 in the regulation of epidermal development and tumorigenesis

    PubMed Central

    Winter, Mircea; Moser, Mirjam A; Meunier, Dominique; Fischer, Carina; Machat, Georg; Mattes, Katharina; Lichtenberger, Beate M; Brunmeir, Reinhard; Weissmann, Simon; Murko, Christina; Humer, Christina; Meischel, Tina; Brosch, Gerald; Matthias, Patrick; Sibilia, Maria; Seiser, Christian

    2013-01-01

    The histone deacetylases HDAC1 and HDAC2 remove acetyl moieties from lysine residues of histones and other proteins and are important regulators of gene expression. By deleting different combinations of Hdac1 and Hdac2 alleles in the epidermis, we reveal a dosage-dependent effect of HDAC1/HDAC2 activity on epidermal proliferation and differentiation. Conditional ablation of either HDAC1 or HDAC2 in the epidermis leads to no obvious phenotype due to compensation by the upregulated paralogue. Strikingly, deletion of a single Hdac2 allele in HDAC1 knockout mice results in severe epidermal defects, including alopecia, hyperkeratosis, hyperproliferation and spontaneous tumour formation. These mice display impaired Sin3A co-repressor complex function, increased levels of c-Myc protein, p53 expression and apoptosis in hair follicles (HFs) and misregulation of HF bulge stem cells. Surprisingly, ablation of HDAC1 but not HDAC2 in a skin tumour model leads to accelerated tumour development. Our data reveal a crucial function of HDAC1/HDAC2 in the control of lineage specificity and a novel role of HDAC1 as a tumour suppressor in the epidermis. PMID:24240174

  17. Phosphorus-based SAHA analogues as histone deacetylase inhibitors.

    PubMed

    Kapustin, Galina V; Fejér, György; Gronlund, Jennifer L; McCafferty, Dewey G; Seto, Edward; Etzkorn, Felicia A

    2003-08-21

    [structure: see text] Three analogues of suberoyl anilide hydroxamic acid (SAHA) with phosphorus metal-chelating functionalities were synthesized as inhibitors of histone deacetylases (HDACs). The compounds showed weak activity for HeLa nuclear extracts (IC(50) = 0.57-6.1 mM), HDAC8 (IC(50) = 0.28-0.41 mM), and histone-deacetylase-like protein (HDLP, IC(50) = 0.33-1.9 mM), suggesting that the transition state of HDAC is not analogous to zinc proteases. Antiproliferative activity against A2780 cancer cells (IC(50) = 0.11-0.12 mM), comparable to SAHA (0.15 mM), was observed.

  18. Treatment of chronic kidney diseases with histone deacetylase inhibitors

    PubMed Central

    Liu, Na; Zhuang, Shougang

    2015-01-01

    Histone deacetylases (HDACs) induce deacetylation of both histone and non-histone proteins and play a critical role in the modulation of physiological and pathological gene expression. Pharmacological inhibition of HDAC has been reported to attenuate progression of renal fibrogenesis in obstructed kidney and reduce cyst formation in polycystic kidney disease. HDAC inhibitors (HDACis) are also able to ameliorate renal lesions in diabetes nephropathy, lupus nephritis, aristolochic acid nephropathy, and transplant nephropathy. The beneficial effects of HDACis are associated with their anti-fibrosis, anti-inflammation, and immunosuppressant effects. In this review, we summarize recent advances on the treatment of various chronic kidney diseases with HDACis in pre-clinical models. PMID:25972812

  19. Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis

    SciTech Connect

    Van Beneden, Katrien; Geers, Caroline; Pauwels, Marina; Mannaerts, Inge; Wissing, Karl M.; Van den Branden, Christiane; Grunsven, Leo A. van

    2013-09-01

    Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors. - Highlights: • Valproic acid is a potent antiproteinuric drug, whereas trichostatin A is not. • Trichostatin A and valproic acid reduce kidney fibrosis in doxorubicin nephropathy. • Both valproic acid and trichostatin A attenuate renal inflammation.

  20. Nicotine inhibits the proliferation by upregulation of nitric oxide and increased HDAC1 in mouse neural stem cells.

    PubMed

    Lee, Hanbyeol; Park, Jeong-Ran; Yang, Jungwon; Kim, Eunjeong; Hong, Seok-Ho; Woo, Heung-Myong; Ryu, Se-Min; Cho, Sung-Joon; Park, Sung-Min; Yang, Se-Ran

    2014-09-01

    Cigarette smoking (CS) is considered one of the major risk factors to cause neurodegenerative disorders. Nicotine is the main chemical in CS which is responsible for dysfunction of the brain as a neuroteratogen. Also, nicotine dependency is a real mental illness and disease. Recently, chronic nicotine exposure has been shown to cause oxidative/nitrosative stress leading to a deleterious condition to cellular death in different brain regions. However, little is known about the effects of nicotine on mouse neural stem cells (mNSCs). The aim of this study is to investigate the effects of nicotine on mNSCs and elucidate underlying mechanisms involved in expression of a diversity of genes regulated by nicotine. When mNSCs were isolated from the whole brain of embryonic day 16 mice treated with nicotine at vehicle, 100, 400, and 800 μM for 5 d, nicotine significantly decreased the number and size of neurospheres. In immunocytochemistry, nicotine-exposed mNSCs expressing nestin showed the shortened filaments and condensed nuclei. In RT-PCR, messenger RNA (mRNA) levels of proliferating cell nuclear antigen (PCNA) and sirtuin1 (SIRT1) were significantly decreased, while the production of nitric oxide and mRNA levels of cyclooxygenase2 (COX-2), tumor necrosis factor-alpha TNF-α, and histone deacetylase 1 (HDAC1) were increased in a dose-dependent manner. In addition, sodium butyrate and valproic acid, HDAC inhibitors, partially rescue proliferation of mNSCs via inhibition of HDAC1 expression and NO production. Taken together, these data demonstrate that prolonged exposure of nicotine decreased proliferation of mNSCs by increased NO and inflammatory cytokine through increased HDAC1. Furthermore, this study could help in the development of a therapy for nicotine-induced neurodegenerative disorder and drug abuse.

  1. Arylstibonic Acids: Novel Inhibitors and Activators of Human Topoisomerase IB

    PubMed Central

    Kim, Hyeongnam; Cardellina, John H.; Akee, Rhone; Champoux, James J.; Stivers, James T.

    2008-01-01

    Human topoisomerase IB (hTopo) forms a covalent phosphotyrosyl linkage with the DNA backbone, and controls genomic DNA topology by relaxing DNA supercoils during the processes of DNA replication, transcription, chromosome condensation and decondensation. The essential role of hTopo in these processes has made it a preeminent anticancer drug target. We have screened a small library of arylstibonic acids for their effects on plasmid supercoil relaxation catalyzed by hTopo. Despite the similar structures of the library compounds, some compounds were found to be effective competitive inhibitors, and others, nonessential activators. Some arylstibonic acids show selectivity in their action against hTopo and the related enzyme from poxvirus (vTopo). Structure-activity relationships and structural modeling suggest that competitive inhibition may result from positioning of the negatively charged stibonic acid and carboxylate groups of the inhibitors into DNA phosphate binding pockets on hTopo. The hTopo activators act by a surprising allosteric mechanism without interfering with DNA binding or binding of the widely used hTopo poison camptothecin. Arylstibonic acid competitive inhibitors may become useful small molecules for elucidating the cellular functions of hTopo. PMID:18508107

  2. Discovery of potent wall teichoic acid early stage inhibitors.

    PubMed

    Labroli, Marc A; Caldwell, John P; Yang, Christine; Lee, Sang Ho; Wang, Hao; Koseoglu, Sandra; Mann, Paul; Yang, Shu-Wei; Xiao, Jing; Garlisi, Charles G; Tan, Christopher; Roemer, Terry; Su, Jing

    2016-08-15

    The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current β-lactam antibiotics and created an urgent need for novel treatment options. Using an S. aureus phenotypic screening strategy, we have identified small molecule early stage wall teichoic acid (WTA) pathway-specific inhibitors predicted to be chemically synergistic with β-lactams. These previously disclosed inhibitors, termed tarocins, demonstrate by genetic and biochemical means inhibition of TarO, the first step in WTA biosynthesis. Tarocins demonstrate potent bactericidal synergy in combination with broad spectrum β-lactam antibiotics across diverse clinical isolates of methicillin-resistant Staphylococci. The synthesis and structure-activity relationships (SAR) of a tarocin series will be detailed. Tarocins and other WTA inhibitors may provide a rational strategy to develop Gram-positive bactericidal β-lactam combination agents active against methicillin-resistant Staphylococci. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Synergy between histone deacetylase inhibitors and DNA-damaging agents is mediated by histone deacetylase 2 in colorectal cancer

    PubMed Central

    Alzoubi, Samer; Brody, Leigh; Rahman, Sunniyat; Mahul-Mellier, Anne-Laure; Mercado, Nicolas; Ito, Kazuhiro; El-Bahrawy, Mona; Silver, Andrew; Boobis, Alan; Bell, Jimmy D.; Hajji, Nabil

    2016-01-01

    Previous studies have associated the overexpression of histone deacetylase 2 (HDAC2) and the presence of TP53 mutations with the progression to advanced stage drug resistant colorectal cancer (CRC). However, the mechanistic link between HDAC2 expression and the TP53 mutational status has remained unexplored. Here, we investigated the function of HDAC2 in drug resistance by assessing the synergistic effects of DNA-targeted chemotherapeutic agents and HDAC inhibitors (HDACis) on two TP53-mutated colorectal adenocarcinoma CRC cell lines (SW480 and HT-29) and on the TP53-wild type carcinoma cell line (HCT116 p53+/+) and its TP53 deficient sub-line (HCT116 p53−/−). We showed that in the untreated SW480 and HT-29 cells the steady-state level of HDAC2 was low compared to a TP53-wild type carcinoma cell line (HCT116 p53+/+). Increased expression of HDAC2 correlated with drug resistance, and depletion by shRNA sensitised the multi-drug resistance cell line HT-29 to CRC chemotherapeutic drugs such as 5-fluorouracil (5-FU) and oxaliplatin (Oxa). Combined treatment with the HDACi suberoylanilide hydroxamic acid plus 5-FU or Oxa reduced the level of HDAC2 expression, modified chromatin structure and induced mitotic cell death in HT-29 cells. Non-invasive bioluminescence imaging revealed significant reductions in xenograft tumour growth with HDAC2 expression level reduced to <50% in treated animals. Elevated levels of histone acetylation on residues H3K9, H4K12 and H4K16 were also found to be associated with resistance to VPA/Dox or SAHA/Dox treatment. Our results suggest that HDAC2 expression rather than the p53 mutation status influences the outcome of combined treatment with a HDACi and DNA-damaging agents in CRC. PMID:27283986

  4. Exploring inhibitor release pathways in histone deacetylases using random acceleration molecular dynamics simulations.

    PubMed

    Kalyaanamoorthy, Subha; Chen, Yi-Ping Phoebe

    2012-02-27

    Molecular channel exploration perseveres to be the prominent solution for eliciting structure and accessibility of active site and other internal spaces of macromolecules. The volume and silhouette characterization of these channels provides answers for the issues of substrate access and ligand swapping between the obscured active site and the exterior of the protein. Histone deacetylases (HDACs) are metal-dependent enzymes that are involved in the cell growth, cell cycle regulation, and progression, and their deregulations have been linked with different types of cancers. Hence HDACs, especially the class I family, are widely recognized as the important cancer targets, and the characterizations of their structures and functions have been of special interest in cancer drug discovery. The class I HDACs are known to possess two different protein channels, an 11 Å and a 14 Å (named channels A and B1, respectively), of which the former is a ligand or substrate occupying tunnel that leads to the buried active site zinc ion and the latter is speculated to be involved in product release. In this work, we have carried out random acceleration molecular dynamics (RAMD) simulations coupled with the classical molecular dynamics to explore the release of the ligand, N-(2-aminophenyl) benzamide (LLX) from the active sites of the recently solved X-ray crystal structure of HDAC2 and the computationally modeled HDAC1 proteins. The RAMD simulations identified significant structural and dynamic features of the HDAC channels, especially the key 'gate-keeping' amino acid residues that control these channels and the ligand release events. Further, this study identified a novel and unique channel B2, a subchannel from channel B1, in the HDAC1 protein structure. The roles of water molecules in the LLX release from the HDAC1 and HDAC2 enzymes are also discussed. Such structural and dynamic properties of the HDAC protein channels that govern the ligand escape reactions will provide

  5. [Design, synthesis, and biological activities of histone deacetylase inhibitors with diketo ester as zinc binding group].

    PubMed

    Lu, Hui; Su, Hong; Yang, Bo; You, Qi-Dong

    2011-03-01

    Histone deacetylases (HDACs) inhibition causes hyperacetylation of histones leading to growth arrest, differentiation and apoptosis of tumor cells, representing a new strategy in cancer therapy. Many of previously reported HDACs inhibitors are hydroxamic acid derivatives, which could chelate the zinc ion in the active site in a bidentate fashion. However, hydroxamic acids occasionally have produced problems such as poor pharmacokinetics, severe toxicity and low selectivity. Herein we describe the identification of a new series of non-hydroxamate HDACs inhibitors bearing diketo ester moieties as zinc binding group. HDACs inhibition assay and antiproliferation assays in vitro against multiple cancer cell lines were used for evaluation. These compounds displayed low antiproliferative activity against solid tumor cells, while good antiproliferative activity against human leukemic monocyte lymphoma cell line U937. Compound CPUYS707 is the best with GI50 value of 0.31 micromol x L(-1) against U937 cells, which is more potent than SAHA and MS-275. HDACs inhibition activity of these compounds is lower than that expected, further evaluation is needed.

  6. Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

    PubMed Central

    2011-01-01

    Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies. PMID:22247744

  7. HDAC-mediated deacetylation of NF-κB is critical for Schwann cell myelination.

    PubMed

    Chen, Ying; Wang, Haibo; Yoon, Sung Ok; Xu, Xiaomei; Hottiger, Michael O; Svaren, John; Nave, Klaus A; Kim, Haesun A; Olson, Eric N; Lu, Q Richard

    2011-04-01

    Schwann cell myelination is tightly regulated by timely expression of key transcriptional regulators that respond to specific environmental cues, but the molecular mechanisms underlying such a process are poorly understood. We found that the acetylation state of NF-κB, which is regulated by histone deacetylases (HDACs) 1 and 2, is critical for orchestrating the myelination program. Mice lacking both HDACs 1 and 2 (HDAC1/2) exhibited severe myelin deficiency with Schwann cell development arrested at the immature stage. NF-κB p65 became heavily acetylated in HDAC1/2 mutants, inhibiting the expression of positive regulators of myelination and inducing the expression of differentiation inhibitors. We observed that the NF-κB protein complex switched from associating with p300 to associating with HDAC1/2 as Schwann cells differentiated. NF-κB and HDAC1/2 acted in a coordinated fashion to regulate the transcriptionally linked chromatin state for Schwann cell myelination. Thus, our results reveal an HDAC-mediated developmental switch for controlling myelination in the peripheral nervous system.

  8. An HDAC-dependent epigenetic mechanism that enhances the efficacy of the antidepressant drug fluoxetine

    PubMed Central

    Schmauss, C.

    2015-01-01

    Depression is a prevalent and debilitating psychiatric illnesses. However, currently prescribed antidepressant drugs are only efficacious in a limited group of patients. Studies on Balb/c mice suggested that histone deacetylase (HDAC) inhibition may enhance the efficacy of the widely-prescribed antidepressant drug fluoxetine. This study shows that reducing HDAC activity in fluoxetine-treated Balb/c mice leads to robust antidepressant and anxiolytic effects. While reducing the activity of class I HDACs 1 and 3 led to antidepressant effects, additional class II HDAC inhibition was necessary to exert anxiolytic effects. In fluoxetine-treated mice, HDAC inhibitors increased enrichment of acetylated histone H4 protein and RNA polymerase II at promotor 3 of the brain-derived neurotrophic factor (Bdnf) gene and increased Bdnf transcription from this promotor. Reducing Bdnf-stimulated tropomyosin kinase B receptor activation in fluoxetine-treated mice with low HDAC activity abolished the behavioral effects of fluoxetine, suggesting that the HDAC-triggered epigenetic stimulation of Bdnf expression is critical for therapeutic efficacy. PMID:25639887

  9. AR-42 induces apoptosis in human hepatocellular carcinoma cells via HDAC5 inhibition.

    PubMed

    Zhang, Mingming; Pan, Yida; Dorfman, Robert G; Chen, Zhaogui; Liu, Fuchen; Zhou, Qian; Huang, Shan; Zhang, Jun; Yang, Dongqin; Liu, Jie

    2016-04-19

    Histone deacetylases (HDACs) play critical roles in apoptosis and contribute to the proliferation of cancer cells. AR-42 is a novel Class I and II HDAC inhibitor that shows cytotoxicity against various human cancer cell lines. The present study aims to identify the target of AR-42 in hepatocellular carcinoma (HCC) as well as evaluate its therapeutic efficacy. We found that HDAC5 was upregulated in HCC tissues compared to adjacent normal tissues, and this was correlated with reduced patient survival. CCK8 and colony-formation assays showed that HDAC5 overexpression promotes proliferation in HCC cell lines. Treatment with AR-42 decreased HCC cell growth and increased caspase-dependent apoptosis, and this was rescued by HDAC5 overexpression. We demonstrated that AR-42 can inhibit the deacetylation activity of HDAC5 and its downstream targets in vitro and in vivo. Taken together, these results demonstrate for the first time that AR-42 targets HDAC5 and induces apoptosis in human hepatocellular carcinoma cells. AR-42 therefore shows potential as a new drug candidate for HCC therapy.

  10. Investigating the selectivity of metalloenzyme inhibitors.

    PubMed

    Day, Joshua A; Cohen, Seth M

    2013-10-24

    The inhibitory activity of a broad group of known metalloenzyme inhibitors against a panel of metalloenzymes was evaluated. Clinically approved inhibitors were selected as well as several other reported metalloprotein inhibitors in order to represent a broad range of metal binding groups (MBGs), including hydroxamic acid, carboxylate, hydroxypyridinonate, thiol, and N-hydroxyurea functional groups. A panel of metalloenzymes, including carbonic anhydrase (hCAII), several matrix metalloproteinases (MMPs), angiotensin converting enzyme (ACE), histone deacetylase (HDAC-2), and tyrosinase (TY), was selected based on their clinical importance for a range of pathologies. In addition, each inhibitor was evaluated for its ability to remove Fe(3+) from holo-transferrin to gauge the ability of the inhibitors to access Fe(3+) from a primary transport protein. The results show that the metalloenzyme inhibitors are quite selective for their intended targets, suggesting that despite their ability to bind metal ions, metalloprotein inhibitors are not prone to widespread off-target enzyme inhibition activity.

  11. HDAC Inhibition Upregulates PD-1 Ligands in Melanoma and Augments Immunotherapy with PD-1 Blockade.

    PubMed

    Woods, David M; Sodré, Andressa L; Villagra, Alejandro; Sarnaik, Amod; Sotomayor, Eduardo M; Weber, Jeffrey

    2015-12-01

    Expression of PD-1 ligands by tumors and interaction with PD-1-expressing T cells in the tumor microenvironment can result in tolerance. Therapies targeting this coinhibitory axis have proven clinically successful in the treatment of metastatic melanoma, non-small cell lung cancer, and other malignancies. Therapeutic agents targeting the epigenetic regulatory family of histone deacetylases (HDAC) have shown clinical success in the treatment of some hematologic malignancies. Beyond direct tumor cell cytotoxicity, HDAC inhibitors have also been shown to alter the immunogenicity and enhance antitumor immune responses. Here, we show that class I HDAC inhibitors upregulated the expression of PD-L1 and, to a lesser degree, PD-L2 in melanomas. Evaluation of human and murine cell lines and patient tumors treated with a variety of HDAC inhibitors in vitro displayed upregulation of these ligands. This upregulation was robust and durable, with enhanced expression lasting past 96 hours. These results were validated in vivo in a B16F10 syngeneic murine model. Mechanistically, HDAC inhibitor treatment resulted in rapid upregulation of histone acetylation of the PD-L1 gene leading to enhanced and durable gene expression. The efficacy of combining HDAC inhibition with PD-1 blockade for treatment of melanoma was also explored in a murine B16F10 model. Mice receiving combination therapy had a slower tumor progression and increased survival compared with control and single-agent treatments. These results highlight the ability of epigenetic modifiers to augment immunotherapies, providing a rationale for combining HDAC inhibitors with PD-1 blockade.

  12. Histone Deacetylase Inhibitors Modulate Interleukin 6-dependent CD4+ T Cell Polarization in Vitro and in Vivo *

    PubMed Central

    Glauben, Rainer; Sonnenberg, Elena; Wetzel, Martin; Mascagni, Paolo; Siegmund, Britta

    2014-01-01

    Histone deacetylase (HDAC) inhibitors have been associated primarily with an anti-proliferative effect in vitro and in vivo. Recent data provide evidence for an anti-inflammatory potency of HDAC inhibitors in models of experimental colitis. Because the balance of T cell subpopulations is critical for the balance of the mucosal immune system, this study explores the regulatory potency of HDAC inhibitors on T cell polarization as a mechanistic explanation for the observed anti-inflammatory effects. Although HDAC inhibition suppressed the polarization toward the pro-inflammatory T helper 17 (Th17) cells, it enhanced forkhead box P3 (FoxP3)+ regulatory T cell polarization in vitro and in vivo at the site of inflammation in the lamina propria. This was paralleled by a down-regulation of the interleukin 6 receptor (IL-6R) on naïve CD4+ T cells on the mRNA as well as on the protein level and changes in the chromatin acetylation at the IL6R gene and its promoter. Downstream of the IL-6R, HDAC inhibition was followed by a decrease in STAT3 phosphorylation as well as retinoic acid receptor-related orphan receptor γT (RORγT) expression, thus identifying the IL-6/STAT3/IL-17 pathway as an important target of HDAC inhibitors. These results directly translated to experimental colitis, where IL-6R expression was suppressed in naïve T cells, paralleled by a significant reduction of Th17 cells in the lamina propria of ITF2357-treated animals, resulting in the amelioration of disease. This study indicates that, in experimental colitis, inhibition of HDAC exerts an anti-inflammatory potency by directing T helper cell polarization via targeting the IL-6 pathway. PMID:24421314

  13. Histone deacetylase inhibitors modulate interleukin 6-dependent CD4+ T cell polarization in vitro and in vivo.

    PubMed

    Glauben, Rainer; Sonnenberg, Elena; Wetzel, Martin; Mascagni, Paolo; Siegmund, Britta

    2014-02-28

    Histone deacetylase (HDAC) inhibitors have been associated primarily with an anti-proliferative effect in vitro and in vivo. Recent data provide evidence for an anti-inflammatory potency of HDAC inhibitors in models of experimental colitis. Because the balance of T cell subpopulations is critical for the balance of the mucosal immune system, this study explores the regulatory potency of HDAC inhibitors on T cell polarization as a mechanistic explanation for the observed anti-inflammatory effects. Although HDAC inhibition suppressed the polarization toward the pro-inflammatory T helper 17 (Th17) cells, it enhanced forkhead box P3 (FoxP3)(+) regulatory T cell polarization in vitro and in vivo at the site of inflammation in the lamina propria. This was paralleled by a down-regulation of the interleukin 6 receptor (IL-6R) on naïve CD4(+) T cells on the mRNA as well as on the protein level and changes in the chromatin acetylation at the IL6R gene and its promoter. Downstream of the IL-6R, HDAC inhibition was followed by a decrease in STAT3 phosphorylation as well as retinoic acid receptor-related orphan receptor γT (RORγT) expression, thus identifying the IL-6/STAT3/IL-17 pathway as an important target of HDAC inhibitors. These results directly translated to experimental colitis, where IL-6R expression was suppressed in naïve T cells, paralleled by a significant reduction of Th17 cells in the lamina propria of ITF2357-treated animals, resulting in the amelioration of disease. This study indicates that, in experimental colitis, inhibition of HDAC exerts an anti-inflammatory potency by directing T helper cell polarization via targeting the IL-6 pathway.

  14. Tanzawaic Acids, a Chemically Novel Set of Bacterial Conjugation Inhibitors

    PubMed Central

    Getino, María; Fernández-López, Raúl; Palencia-Gándara, Carolina; Campos-Gómez, Javier; Sánchez-López, Jose M.; Martínez, Marta; Fernández, Antonio; de la Cruz, Fernando

    2016-01-01

    Bacterial conjugation is the main mechanism for the dissemination of multiple antibiotic resistance in human pathogens. This dissemination could be controlled by molecules that interfere with the conjugation process. A search for conjugation inhibitors among a collection of 1,632 natural compounds, identified tanzawaic acids A and B as best hits. They specially inhibited IncW and IncFII conjugative systems, including plasmids mobilized by them. Plasmids belonging to IncFI, IncI, IncL/M, IncX and IncH incompatibility groups were targeted to a lesser extent, whereas IncN and IncP plasmids were unaffected. Tanzawaic acids showed reduced toxicity in bacterial, fungal or human cells, when compared to synthetic conjugation inhibitors, opening the possibility of their deployment in complex environments, including natural settings relevant for antibiotic resistance dissemination. PMID:26812051

  15. Tanzawaic Acids, a Chemically Novel Set of Bacterial Conjugation Inhibitors.

    PubMed

    Getino, María; Fernández-López, Raúl; Palencia-Gándara, Carolina; Campos-Gómez, Javier; Sánchez-López, Jose M; Martínez, Marta; Fernández, Antonio; de la Cruz, Fernando

    2016-01-01

    Bacterial conjugation is the main mechanism for the dissemination of multiple antibiotic resistance in human pathogens. This dissemination could be controlled by molecules that interfere with the conjugation process. A search for conjugation inhibitors among a collection of 1,632 natural compounds, identified tanzawaic acids A and B as best hits. They specially inhibited IncW and IncFII conjugative systems, including plasmids mobilized by them. Plasmids belonging to IncFI, IncI, IncL/M, IncX and IncH incompatibility groups were targeted to a lesser extent, whereas IncN and IncP plasmids were unaffected. Tanzawaic acids showed reduced toxicity in bacterial, fungal or human cells, when compared to synthetic conjugation inhibitors, opening the possibility of their deployment in complex environments, including natural settings relevant for antibiotic resistance dissemination.

  16. Tall oil fatty acid anhydrides as corrosion inhibitor intermediates

    SciTech Connect

    Fischer, E.R.; Parker, J.E. III

    1995-12-01

    Electrochemical corrosion of carbon steel tubulars in producing oil wells causes lost production and necessitates costly repairs. Corrosive environments exists where hydrocarbons and an aqueous phase are being extracted from producing wells. Tubing life has been extended four fold with the development of organic corrosion inhibitors and concentric configuration treatment. Anhydrides derived from tall oil fatty acids offer enhanced corrosion inhibition properties as compared to traditional dimer/trimer acids. The chemistry of this intermediate and its use in corrosion inhibition for down hole applications, as well as the synthesis of novel oil and water-soluble derivatives will be discussed.

  17. Synthesis of 11-Thialinoleic Acid and 14-Thialinoleic Acid, Inhibitors of Soybean and Human Lipoxygenases

    PubMed Central

    Jacquot, Cyril; McGinley, Chris M.; Plata, Erik; Holman, Theodore R.

    2010-01-01

    Lipoxygenases catalyse the oxidation of polyunsaturated fatty acids and have been invoked in many diseases including cancer, atherosclerosis and Alzheimer’s disease. Currently, no X-ray structures are available with substrate or substrate analogues bound in a productive conformation. Such structures would be very useful for examining interactions between substrate and active site residues. Reported here are the syntheses of linoleic acid analogues containing a sulphur atom at the 11 or 14 positions. The key steps in the syntheses were the incorporation of sulphur using nucleophilic attack of metallated alkynes on electrophilic sulphur compounds and the subsequent stereospecific tantalum-mediated reduction of the alkynylsulphide to the cis-alkenylsulphide. Kinetic assays performed with soybean lipoxygenase-1 showed that both 11-thialinoleic acid and 14-thialinoleic acid were competitive inhibitors with respect to linoleic acid with Ki values of 22 and 35 µM, respectively. On the other hand, 11-thialinoleic acid was a noncompetitive inhibitor with respect to arachidonic acid with Kis and Kii values of 48 and 36 µM, respectively. 11-Thialinoleic acid was also a noncompetitive inhibitor of human 15-lipoxygenase-1 with arachidonic acid (Kis = 11.4 µM, Kii = 18.1 µM) or linoleic acid as substrate (Kis = 20.1 µM, Kii = 20.0 µM), and a competitive inhibitor of human 12-lipoxygenase with arachidonic acid as substrate (Ki = 2.5 µM). The presence of inhibitor did not change the regioselectivity of soybean lipoxygenase-1, human 12- or 15-lipoxygenase-1. PMID:18972057

  18. Behavior of aspartic acid as a corrosion inhibitor for steel

    SciTech Connect

    Kalota, D.J.; Silverman, D.C. )

    1994-02-01

    Corrosion inhibition of steel by aspartic acid (C[sub 4]H[sub 7]NO[sub 4]), an amino acid of low molecular weight, was found to depend strongly on pH. At a pH less than the ionization constant at [approximately]9.5 to 10 (measured at 25 C), C[sub 4]H[sub 7]NO[sub 4] appeared to accelerate corrosion. Above the pH, it acted as a corrosion inhibitor for steel. A specially constructed potential-pH diagram for iron (Fe) that incorporated C[sub 4]H[sub 7]NO[sub 4] showed the change in behavior was accompanied by the most stable thermodynamic state changing from an iron aspartate complex to iron oxide. Polymerized C[sub 4]H[sub 7]NO[sub 4] (polyaspartic acid) behaved in a similar manner. Some other amino acids of low molecular weight behaved similarly.

  19. Histone acetylation inhibitors promote axon growth in adult dorsal root ganglia neurons.

    PubMed

    Lin, Shen; Nazif, Kutaiba; Smith, Alexander; Baas, Peter W; Smith, George M

    2015-08-01

    Intrinsic mechanisms that guide damaged axons to regenerate following spinal cord injury remain poorly understood. Manipulation of posttranslational modifications of key proteins in mature neurons could reinvigorate growth machinery after injury. One such modification is acetylation, a reversible process controlled by two enzyme families, the histone deacetylases (HDACs) and the histone acetyl transferases (HATs), acting in opposition. Whereas acetylated histones in the nucleus are associated with upregulation of growth-promoting genes, deacetylated tubulin in the axoplasm is associated with more labile microtubules, conducive to axon growth. This study investigates the effects of HAT and HDAC inhibitors on cultured adult dorsal root ganglia (DRG) neurons and shows that inhibition of HATs by anacardic acid or CPTH2 improves axon outgrowth, whereas inhibition of HDACs by TSA or tubacin inhibits axon growth. Anacardic acid increased the number of axons able to cross an inhibitory chondroitin sulfate proteoglycan border. Histone acetylation but not tubulin acetylation level was affected by HAT inhibitors, whereas tubulin acetylation levels were increased in the presence of the HDAC inhibitor tubacin. Although the microtubule-stabilizing drug taxol did not have an effect on the lengths of DRG axons, nocodazole decreased axon lengths. Determining the mechanistic basis will require future studies, but this study shows that inhibitors of HAT can augment axon growth in adult DRG neurons, with the potential of aiding axon growth over inhibitory substrates produced by the glial scar. © 2015 Wiley Periodicals, Inc.

  20. Lacosamide reduces HDAC levels in the brain and improves memory: Potential for treatment of Alzheimer's disease.

    PubMed

    Bang, Shraddha R; Ambavade, Shirishkumar D; Jagdale, Priti G; Adkar, Prafulla P; Waghmare, Arun B; Ambavade, Prashant D

    2015-07-01

    Lacosamide, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of epilepsy. Some HDAC inhibitors have been proven effective for the treatment of memory disorders. The present investigation was designed to evaluate the effect of lacosamide on memory and brain HDAC levels. The effect on memory was evaluated in animals with scopolamine-induced amnesia using the elevated plus maze, object recognition test, and radial arm maze. The levels of acetylcholinesterase and HDAC in the cerebral cortex were evaluated. Lacosamide at doses of 10 and 30mg/kg significantly reduced the transfer latency in the elevated plus maze. Lacosamide at a dose of 30mg/kg significantly increased the time spent with a familiar object in the object recognition test at the 24h interval and decreased the time spent in the baited arm. Moreover, at this dose, the number of errors in the radial arm maze at 3 and 24h intervals was minimized and a reduction in the level of HDAC1, but not acetylcholinesterase, was observed in the cerebral cortex. These effects of lacosamide are equivalent to those of piracetam at a dose of 300mg/kg. These results suggest that lacosamide at a 30mg/kg dose improves disrupted memory, possibly by inhibiting HDAC, and could be used to treat amnesic symptoms of Alzheimer's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Insights into the activation mechanism of class I HDAC complexes by inositol phosphates

    PubMed Central

    Watson, Peter J.; Millard, Christopher J.; Riley, Andrew M.; Robertson, Naomi S.; Wright, Lyndsey C.; Godage, Himali Y.; Cowley, Shaun M.; Jamieson, Andrew G.; Potter, Barry V. L.; Schwabe, John W. R.

    2016-01-01

    Histone deacetylases (HDACs) 1, 2 and 3 form the catalytic subunit of several large transcriptional repression complexes. Unexpectedly, the enzymatic activity of HDACs in these complexes has been shown to be regulated by inositol phosphates, which bind in a pocket sandwiched between the HDAC and co-repressor proteins. However, the actual mechanism of activation remains poorly understood. Here we have elucidated the stereochemical requirements for binding and activation by inositol phosphates, demonstrating that activation requires three adjacent phosphate groups and that other positions on the inositol ring can tolerate bulky substituents. We also demonstrate that there is allosteric communication between the inositol-binding site and the active site. The crystal structure of the HDAC1:MTA1 complex bound to a novel peptide-based inhibitor and to inositol hexaphosphate suggests a molecular basis of substrate recognition, and an entropically driven allosteric mechanism of activation. PMID:27109927

  2. HDAC8 overexpression in mesenchymal stromal cells from JAK2+ myeloproliferative neoplasms: a new therapeutic target?

    PubMed

    Ramos, Teresa L; Sánchez-Abarca, Luis Ignacio; Redondo, Alba; Hernández-Hernández, Ángel; Almeida, Antonio M; Puig, Noemí; Rodríguez, Concepción; Ortega, Rebeca; Preciado, Silvia; Rico, Ana; Muntión, Sandra; González Porras, José Ramón; Del Cañizo, Consuelo; Sánchez-Guijo, Fermín

    2017-03-07

    Histone deacetylases (HDACs) are involved in epigenetic modulation and their aberrant expression has been demonstrated in myeloproliferative neoplasms (MPN). HDAC8 inhibition has been shown to inhibit JAK2/STAT5 signaling in hematopoietic cells from MPN. Nevertheless, the role of HDAC8 expression in bone marrow-mesenchymal stromal cells (BM-MSC) has not been assessed. In the current work we describe that HDAC8 is significantly over-expressed in MSC from in JAK-2 positive MPN compared to those from healthy-donors (HD-MSC). Using a selective HDAC8 inhibitor (PCI34051), we verified that the subsequent decrease in the protein and mRNA expression of HDAC8 is linked with an increased apoptosis of malignant MSC whereas it has no effects on normal MSC. In addition, HDAC8 inhibition in MPN-MSC also decreased their capacity to maintain neoplastic hematopoiesis, by increasing the apoptosis, cell-cycle arrest and colony formation of JAK2+-hematopoietic cells. Mechanistic studies using different MPN cell lines revealed that PCI34051 induced their apoptosis, which is enhanced when were co-cultured with JAK2V617F-MSC, decreased their colony formation and the phosphorylation of STAT3 and STAT5. In summary, we show for the first time that the inhibition of HDAC8 in MSC from JAK2+ MPN patients selectively decreases their hematopoietic-supporting ability, suggesting that HDAC8 may be a potential therapeutic target in this setting by acting not only on hematopoietic cells but also on the malignant microenvironment.

  3. HDAC8 overexpression in mesenchymal stromal cells from JAK2+ myeloproliferative neoplasms: a new therapeutic target?

    PubMed Central

    Ramos, Teresa L.; Sánchez-Abarca, Luis Ignacio; Redondo, Alba; Hernández-Hernández, Ángel; Almeida, Antonio M.; Puig, Noemí; Rodríguez, Concepción; Ortega, Rebeca; Preciado, Silvia; Rico, Ana; Muntión, Sandra; González Porras, José Ramón; Cañizo, Consuelo Del; Sánchez-Guijo, Fermín

    2017-01-01

    Histone deacetylases (HDACs) are involved in epigenetic modulation and their aberrant expression has been demonstrated in myeloproliferative neoplasms (MPN). HDAC8 inhibition has been shown to inhibit JAK2/STAT5 signaling in hematopoietic cells from MPN. Nevertheless, the role of HDAC8 expression in bone marrow-mesenchymal stromal cells (BM-MSC) has not been assessed. In the current work we describe that HDAC8 is significantly over-expressed in MSC from in JAK-2 positive MPN compared to those from healthy-donors (HD-MSC). Using a selective HDAC8 inhibitor (PCI34051), we verified that the subsequent decrease in the protein and mRNA expression of HDAC8 is linked with an increased apoptosis of malignant MSC whereas it has no effects on normal MSC. In addition, HDAC8 inhibition in MPN-MSC also decreased their capacity to maintain neoplastic hematopoiesis, by increasing the apoptosis, cell-cycle arrest and colony formation of JAK2+-hematopoietic cells. Mechanistic studies using different MPN cell lines revealed that PCI34051 induced their apoptosis, which is enhanced when were co-cultured with JAK2V617F-MSC, decreased their colony formation and the phosphorylation of STAT3 and STAT5. In summary, we show for the first time that the inhibition of HDAC8 in MSC from JAK2+ MPN patients selectively decreases their hematopoietic-supporting ability, suggesting that HDAC8 may be a potential therapeutic target in this setting by acting not only on hematopoietic cells but also on the malignant microenvironment. PMID:28390197

  4. Hippocampal HDAC4 contributes to postnatal fluoxetine-evoked depression-like behavior.

    PubMed

    Sarkar, Ambalika; Chachra, Parul; Kennedy, Pamela; Pena, Catherine J; Desouza, Lynette A; Nestler, Eric J; Vaidya, Vidita A

    2014-08-01

    Fluoxetine treatment in adulthood evokes antidepressant and anxiolytic responses. Paradoxically, postnatal fluoxetine (PNFlx) induces persistent depression- and anxiety-like behaviors. The mechanistic underpinnings of this paradox remain poorly understood. Here, we examined specific molecular changes in the rat hippocampus that accompany perturbed emotionality observed across life following PNFlx. PNFlx-induced hippocampal gene regulation observed in microarray and quantitative PCR studies indicate functional enrichment of genes involved in response to organic substances, protein kinase pathways, DNA binding, and transcriptional repression. We noted specific transcripts (Hdac4, mammalian target of rapamycin (mTOR), Gnai1, protein kinase C gamma (Prkcc), and hyperpolarization-activated cyclic nucleotide-gated channel 1 (Hcn1)) that were consistently dysregulated across life, and selectively influenced by postnatal, but not adult, fluoxetine. Increased histone deacetylase-4 (HDAC4) recruitment, accompanied by decreased activating histone acetylation marks at the mTOR and Gnai1 promoters, indicate a role for HDAC4 in PNFlx-mediated gene dysregulation. Strikingly, coadministration of the HDAC inhibitor sodium butyrate with PNFlx prevented the dysregulation of Hdac4 and mTOR, and the emergence of depression- and anxiety-like behavior. Importantly, we also find that retreatment of PNFlx animals with fluoxetine in adulthood reversed the increased Hdac4 expression, prevented HDAC4 recruitment to the mTOR and Gnai1 promoters, and attenuated the decline in mTOR and Gnai1 expression, coincident with normalization of PNFlx-evoked depression- and anxiety-like behavior. Further, we show that viral-mediated hippocampal overexpression of Hdac4 was sufficient to induce depression-, but not anxiety-, like behavior in adulthood. Our results highlight the unique nature of molecular signatures evoked by PNFlx, and implicate HDAC4 in the dysregulated gene expression and emergence of

  5. Inhibition of HDAC6 protects against rhabdomyolysis-induced acute kidney injury.

    PubMed

    Shi, Yingfeng; Xu, Liuqing; Tang, Jinhua; Fang, Lu; Ma, Shuchen; Ma, Xiaoyan; Nie, Jing; Pi, Xiaoling; Qiu, Andong; Zhuang, Shougang; Liu, Na

    2017-03-01

    Histone deacetylase 6 (HDAC6) inhibition has been reported to protect against ischemic stroke and prolong survival after sepsis in animal models. However, it remains unknown whether HDAC6 inhibition offers a renoprotective effect after acute kidney injury (AKI). In this study, we examined the effect of tubastatin A (TA), a highly selective inhibitor of HDAC6, on AKI in a murine model of glycerol (GL) injection-induced rhabdomyolysis. Following GL injection, the mice developed severe acute tubular injury as indicated by renal dysfunction; expression of neutrophil gelatinase-associated lipocalin (NGAL), an injury marker of renal tubules; and an increase of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells. These changes were companied by increased HDAC6 expression in the cytoplasm of renal tubular cells. Administration of TA significantly reduced serum creatinine and blood urea nitrogen levels as well as attenuated renal tubular damage in injured kidneys. HDAC6 inhibition also resulted in decreased expression of NGAL, reduced apoptotic cell, and inactivated caspase-3 in the kidney after acute injury. Moreover, injury to the kidney increased phosphorylation of nuclear factor (NF)-κB and expression of multiple cytokines/chemokines including tumor necrotic factor-α and interleukin-6 and monocyte chemoattractant protein-1, as well as macrophage infiltration. Treatment with TA attenuated all those responses. Finally, HDAC6 inhibition reduced the level of oxidative stress by suppressing malondialdehyde (MDA) and preserving expression of superoxide dismutase (SOD) in the injured kidney. Collectively, these data indicate that HDAC6 contributes to the pathogenesis of rhabdomyolysis-induced AKI and suggest that HDAC6 inhibitors have therapeutic potential for AKI treatment.

  6. Okadaic acid: the archetypal serine/threonine protein phosphatase inhibitor.

    PubMed

    Dounay, A B; Forsyth, C J

    2002-11-01

    As the first recognized member of the "okadaic acid class" of phosphatase inhibitors, the marine natural product okadaic acid is perhaps the most well-known member of a diverse array of secondary metabolites that have emerged as valuable probes for studying the roles of various cellular protein serine/threonine phosphatases. This review provides a historical perspective on the role that okadaic acid has played in stimulating a broad spectrum of modern scientific research as a result of the natural product's ability to bind to and inhibit important classes of protein serine / threonine phosphatases. The relationships between the structure and biological activities of okadaic acid are briefly reviewed, as well as the structural information regarding the particular cellular receptors protein phosphatases 1 (PP1) and 2A. Laboratory syntheses of okadaic acid and its analogs are thoroughly reviewed. Finally, an interpretation of the critical contacts observed between okadaic acid and PP1 by X-ray crystallography is provided, and specific molecular recognition hypotheses that are testable via the synthesis and assay of non-natural analogs of okadaic acid are suggested.

  7. Long-Term Culture of Porcine Induced Pluripotent Stem-Like Cells Under Feeder-Free Conditions in the Presence of Histone Deacetylase Inhibitors.

    PubMed

    Petkov, Stoyan; Glage, Silke; Nowak-Imialek, Monika; Niemann, Heiner

    2016-03-01

    The reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) is a complex process that involves significant epigenetic alterations in the reprogrammed cells. Epigenetic modifiers such as histone deacetylase (HDAC) inhibitors have been shown to increase the efficiency of derivation of iPSCs in humans and mice. In this study, we used three HDAC inhibitors, valproic acid, sodium butyrate, and suberoylanilide hydroxamic acid, together with ascorbic acid, for derivation and long-term feeder-free culture of porcine iPS-like cells. In the absence of exogenous growth factors and/or small molecules, these inhibitors were able to maintain the expression of key pluripotency markers, including genes known to be specific for naive pluripotent state in mouse stem cells, for over 60 passages under feeder-free conditions. Surprisingly, the cells became dependent on HDAC inhibitors for the maintenance of proliferation. Moreover, despite showing successful integration into blastocysts upon injection, the cells were unable to undergo normal differentiation in vitro and in vivo in the form of teratomas. Our results suggest that HDAC inhibitors maintain pluripotency gene expression of porcine iPSC-like cells in long-term culture, but prevent lineage specification, requiring further optimization of culture conditions for porcine iPSC derivation.

  8. The effects of the histone deacetylase inhibitor romidepsin (FK228) are enhanced by aspirin (ASA) in COX-1 positive ovarian cancer cells through augmentation of p21.

    PubMed

    Son, Deok-Soo; Wilson, Andrew J; Parl, Angelika K; Khabele, Dineo

    2010-06-01

    Histone deacetylase (HDAC) inhibitors have shown preclinical efficacy in solid tumors, including ovarian cancers. Our group has published that the HDAC inhibitor, romidepsin (FK228) suppresses ovarian cancer cell growth at nanomolar concentrations in vitro. HDAC inhibitors appear to be even more effective when used in combination with other antitumor agents. However, it remains unclear which antitumor agents are best suited for combination therapy. A recent report suggested that aspirin (acetylsalicylic acid, ASA ) is synergistic with HDAC inhibitors in ovarian cancer cells. ASA is a relatively selective inhibitor of cyclooxygenase-1 (COX-1) and has anti-proliferative effects in ovarian cancer cells. The goal of this study was to investigate the impact of ASA on the activity of the HDAC inhibitor, FK228 in COX-1 positive (OVCAR-3) and COX-1 negative (SKOV-3) human ovarian cancer cell lines. The growth inhibitory effects of FK228 were enhanced by ASA in COX-1 positive ovarian cancer cells. In contrast, ASA had no influence on the results of FK228 treatment in COX-1 negative ovarian cancer cells. Upregulation of the cell cycle control protein p21 was induced robustly by FK228 in both cell lines. In the COX-1 positive cells, p21 expression was augmented by the addition of ASA to FK228 treatment. Furthermore, COX-1 siRNA attenuated the effects of combined ASA and FK228 on the levels of p21 expression and the amount of growth inhibition. The additional increase in p21 by ASA in FK228-treated cells was not observed at the promoter or transcriptional levels. However, a significant delay in p21 protein degradation in the presence of ASA and FK228 in COX-1 positive cells was associated with inhibition of proteasome activity. Our study provides a potential rationale for combining ASA with HDAC inhibitors in a subset of ovarian cancers.

  9. HDAC3 Is Required for the Downregulation of RORγt during Thymocyte Positive Selection.

    PubMed

    Philips, Rachael L; Chen, Meibo W; McWilliams, Douglas C; Belmonte, Paul J; Constans, Megan M; Shapiro, Virginia Smith

    2016-07-15

    To generate functional peripheral T cells, proper gene regulation during T cell development is critical. In this study, we found that histone deacetylase (HDAC) 3 is required for T cell development. T cell development in CD2-icre HDAC3 conditional knockout (cKO) mice (HDAC3-cKO) was blocked at positive selection, resulting in few CD4 and CD8 T cells, and it could not be rescued by a TCR transgene. These single-positive thymocytes failed to upregulate Bcl-2, leading to increased apoptosis. HDAC3-cKO mice failed to downregulate retinoic acid-related orphan receptor (ROR) γt during positive selection, similar to the block in positive selection in RORγt transgenic mice. In the absence of HDAC3, the RORC promoter was hyperacetylated. In the periphery, the few CD4 T cells present were skewed toward RORγt(+) IL-17-producing Th17 cells, leading to inflammatory bowel disease. Positive selection of CD8 single-positive thymocytes was restored in RORγt-KO Bcl-xL transgenic HDAC3-cKO mice, demonstrating that HDAC3 is required at positive selection to downregulate RORγt.

  10. HDAC9 is an epigenetic repressor of kidney angiotensinogen establishing a sex difference.

    PubMed

    Bourgeois, Camille T; Satou, Ryousuke; Prieto, Minolfa C

    2017-01-01

    Sexual difference has been shown in the pathogenesis of chronic kidney disease induced by hypertension. Females are protected from hypertension and related end-organ damage. Augmentation of renal proximal tubular angiotensinogen (AGT) expression can promote intrarenal angiotensin formation and the development of associated hypertension and kidney injury. Female rodents exhibit lower intrarenal AGT levels than males under normal conditions, suggesting that the suppressed intrarenal AGT production by programmed mechanisms in females may provide protection from these diseases. This study was performed to examine whether epigenetic mechanisms serve as repressors of AGT. Male and female Sprague Dawley rats were used to investigate sex differences of systemic, hepatic, and intrarenal AGT levels. All histone deacetylase (HDAC) mRNA levels in the kidneys were determined using a PCR array. HDAC9 protein expression in the kidneys and cultured renal proximal tubular cells (PTC) was analyzed by Western blot analysis and immunohistochemistry. The effects of HDAC9 on AGT expression were evaluated by using an inhibitor and siRNA. ChIP assay was performed to investigate the interaction between the AGT promoter and HDAC9. Plasma and liver AGT levels did not show differences between male and female Sprague-Dawley rats. In contrast, females exhibited lower AGT levels than males in the renal cortex and urine. In the absence of supplemented sex hormones, primary cultured renal cortical cells isolated from female rats sustained lower AGT levels than those from males, suggesting that the kidneys have a unique mechanism of AGT regulation controlled by epigenetic factors rather than sex hormones. HDAC9 mRNA and protein levels were higher in the renal cortex of female rats versus male rats (7.09 ± 0.88, ratio to male) while other HDACs did not exhibit a sex difference. HDAC9 expression was localized in PTC which are the primary source of intrarenal AGT. Importantly, HDAC9 knockdown

  11. miR-124 and miR-9 Mediated Downregulation of HDAC5 Promotes Neurite Development Through Activating MEF2C- GPM6A Pathway.

    PubMed

    Gu, Xi; Fu, Congcong; Lin, Lifang; Liu, Shuhu; Su, Xiaohong; Li, Aili; Wu, Qiaoqi; Jia, Chunhong; Zhang, Peidong; Chen, Lu; Zhu, Xinhong; Wang, Xuemin

    2017-03-23

    The class IIa histone deacetylases (HDACs) play important roles in the central nervous system during diverse biological processes such as synaptic plasticity, axon regeneration, cell apoptosis, and neural differentiation. Although it is known that HDAC5 regulates neuronal differentiation, neither the physiological function nor the regulation of HDAC5 in neuronal differentiation is clear. Here, we identify HDAC5 as an inhibitor of neurite elongation and show that HDAC5 is regulated by the brain enriched microRNA miR-124 and miR-9. We discover that HDAC5 inhibits neurite extension both in differentiated P19 cells and primary neurons. We also show that the neuronal membrane glycoprotein GPM6A (M6a) is a direct target gene of HDAC5 regulated transcriptional factor MEF2C. HDAC5 inhibits neurite elongation, acting at least partially via a MEF2C/M6a signaling pathway. We also confirmed the miR-124/miR-9 regulated HDAC5-MEF2C-M6a pathway regulates neurite development in primary neurons. Thus, HDAC5 emerges as a cellular conductor of MEF2C and M6a activity and is regulated by miR-124 and miR-9 to control neurite development. This article is protected by copyright. All rights reserved.

  12. Molecular identification of PpHDAC1, the first histone deacetylase fron the slime mold Physarum polycephalum.

    PubMed

    Brandtner, Eva-Maria; Lechner, Thomas; Loidl, Peter; Lusser, Alexandra

    2002-01-01

    The dynamic state of post-translational acetylation of eukaryotic histones is maintained by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HATs and HDACs have been shown to be components of various regulatory protein complexes in the cell. Their enzymatic activities, intracellular localization and substrate specificities are regulated in a complex, cell cycle related manner. In the myxomycete Physarum polycephalum multiple HATs and HDACs can be distinguished in biochemical terms and they exhibit dynamic activity patterns depending on the cell cycle stage. Here we report on the cloning of the first P. polycephalum HDAC (PpHDAC1) related to the S. cerevisiae Rpd3 protein. The expression pattern of PpHDAC1 mRNA was analysed at different time points of the cell cycle and found to be largely constant. Treatment of macroplasmodia with the HDAC inhibitor trichostatin A at several cell cycle stages resulted in a significant delay in entry into mitosis of treated versus untreated plasmodia. No effect of TSA treatment could be observed on PpHDAC1 expression itself.

  13. Arachidonoylserotonin and other novel inhibitors of fatty acid amide hydrolase.

    PubMed

    Bisogno, T; Melck, D; De Petrocellis, L; Bobrov MYu; Gretskaya, N M; Bezuglov, V V; Sitachitta, N; Gerwick, W H; Di Marzo, V

    1998-07-30

    Fatty acid amide hydrolase (FAAH) catalyzes the hydrolysis of bioactive fatty acid amides and esters such as the endogenous cannabinoid receptor ligands, anandamide (N-arachidonoyl-ethanolamine) and 2-arachidonoylglycerol, and the putative sleep inducing factor cis-9-octadecenoamide (oleamide). Most FAAH blockers developed to date also inhibit cytosolic phospholipase A2 (cPLA2) and/or bind to the CB1 cannabinoid receptor subtype. Here we report the finding of four novel FAAH inhibitors, two of which, malhamensilipin A and grenadadiene, were screened out of a series of thirty-two different algal natural products, and two others, arachidonoylethylene glycol (AEG) and arachidonoyl-serotonin (AA-5-HT) were selected out of five artificially functionalized polyunsaturated fatty acids. When using FAAH preparations from mouse neuroblastoma N18TG2 cells and [14C]anandamide as a substrate, the IC50s for these compounds ranged from 12.0 to 26 microM, the most active compound being AA-5-HT. This substance was also active on FAAH from rat basophilic leukaemia (RBL-2H3) cells (IC50 = 5.6 microM), and inhibited [14C]anandamide hydrolysis by both N18TG2 and RBL-2H3 intact cells without affecting [14C]anandamide uptake. While AEG behaved as a competitive inhibitor and was hydrolyzed to arachidonic acid (AA) by FAAH preparations, AA-5-HT was resistant to FAAH-catalyzed hydrolysis and behaved as a tight-binding, albeit non-covalent, mixed inhibitor. AA-5-HT did not interfere with cPLA2-mediated, ionomycin or antigen-induced release of [3H]AA from RBL-2H3 cells, nor with cPLA2 activity in cell-free experiments. Finally, AA-5-HT did not activate CB1 cannabinoid receptors since it acted as a very weak ligand in in vitro binding assays, and, at 10-15 mg/kg body weight, it was not active in the 'open field', 'hot plate' and rectal hypothermia tests carried out in mice. Conversely AEG behaved as a cannabimimetic substance in these tests as well as in the 'ring' immobility test where AA-5

  14. Thermal copoly/amino acids/ as inhibitors of glyoxalase I

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Syren, R. M.; Windsor, C. R.

    1979-01-01

    A number of copoly(alpha-amino acids) have been prepared thermally; some have been found to function as inhibitors of glyoxalase I, an enzyme which occupies a central position in Szent-Gyorgyi's theory of tumour genesis. These polymers are also of interest in the search for synthetic peptides having carcinostatic activity, since many natural peptides are active. The way in which the inhibitory activity varies with composition of the synthetic polymers has been investigated. Various properties (hydrophobicity, molecular weight, UV absorption, kinetic type) have been examined in a search for correlates of inhibitory activity.

  15. Discovery of novel BTK inhibitors with carboxylic acids.

    PubMed

    Gao, Xiaolei; Wang, James; Liu, Jian; Guiadeen, Deodial; Krikorian, Arto; Boga, Sobhana Babu; Alhassan, Abdul-Basit; Selyutin, Oleg; Yu, Wensheng; Yu, Younong; Anand, Rajan; Liu, Shilan; Yang, Chundao; Wu, Hao; Cai, Jiaqiang; Cooper, Alan; Zhu, Hugh; Maloney, Kevin; Gao, Ying-Duo; Fischmann, Thierry O; Presland, Jeremy; Mansueto, My; Xu, Zangwei; Leccese, Erica; Zhang-Hoover, Jie; Knemeyer, Ian; Garlisi, Charles G; Bays, Nathan; Stivers, Peter; Brandish, Philip E; Hicks, Alexandra; Kim, Ronald; Kozlowski, Joeseph A

    2017-03-15

    We report the design and synthesis of a series of novel Bruton's Tyrosine Kinase (BTK) inhibitors with a carboxylic acid moiety in the ribose pocket. This series of compounds has demonstrated much improved off-target selectivities including adenosine uptake (AdU) inhibition compared to the piperidine amide series. Optimization of the initial lead compound 4 based on BTK enzyme inhibition, and human peripheral blood mononuclear cell (hPBMC) and human whole blood (hWB) activity led to the discovery of compound 40, with potent BTK inhibition, reduced off target activities, as well as favorable pharmacokinetic profile in both rat and dog.

  16. HDAC8 substrates: Histones and beyond.

    PubMed

    Wolfson, Noah A; Pitcairn, Carol Ann; Fierke, Carol A

    2013-02-01

    The lysine deacetylase family of enzymes (HDACs) was first demonstrated to catalyze deacetylation of acetyllysine residues on histones. In subsequent years, HDACs have been shown to recognize a large pool of acetylated nonhistone proteins as substrates. Recently, thousands of acetylated proteins have been discovered, yet in most cases, the HDAC that catalyzes deacetylation in vivo has not been identified. This gap has created the need for better in vivo, in vitro, and in silico approaches for determining HDAC substrates. While HDAC8 is the best kinetically and structurally characterized HDAC, few efficient substrates have yet been substantiated in vivo. In this review, we delineate factors that may be important for determining HDAC8 substrate recognition and catalytic activity, including structure, complex formation, and post-translational modifications. This summary provides insight into the challenges of identifying in vivo substrates for HDAC8, and provides a good vantage point for understanding the variables important for predicting HDAC substrate recognition. Copyright © 2012 Wiley Periodicals, Inc.

  17. Design, synthesis, and biological evaluation of novel histone deacetylase 1 inhibitors through click chemistry.

    PubMed

    Sun, Qiao; Yao, Yiwu; Liu, Chunping; Li, Hua; Yao, Hequan; Xue, Xiaowen; Liu, Jinsong; Tu, Zhengchao; Jiang, Sheng

    2013-06-01

    We report the design, synthesis, and biological evaluation of a new series of HDAC1 inhibitors using click chemistry. Compound 17 bearing a phenyl ring at meta-position was identified to show much better selectivity for HDAC1 over HDAC7 than SAHA. The compond 17 also showed better in vitro anticancer activities against several cancer cell lines than that of SAHA. This work could serve as a foundation for further exploration of selective HDAC inhibitors using the compound 17 molecular scaffold.

  18. Valproic acid enhances bosutinib cytotoxicity in colon cancer cells.

    PubMed

    Mologni, Luca; Cleris, Loredana; Magistroni, Vera; Piazza, Rocco; Boschelli, Frank; Formelli, Franca; Gambacorti-Passerini, Carlo

    2009-04-15

    Unbalanced histone deacetylase (HDAC) hyperactivity is a common feature of tumor cells. Inhibition of HDAC activity is often associated with cancer cell growth impairment and death. Valproic acid (VPA) is a HDAC inhibitor used for the treatment of epilepsy. It has recently been recognized as a promising anticancer drug. We investigated the effects of VPA on growth and survival of colon cancer cells. VPA caused growth inhibition and programmed cell death that correlated with histone hyperacetylation. VPA modulated the expression of various factors involved in cell cycle control and apoptosis and induced caspase activation. Interestingly, VPA induced downregulation of c-Src and potentiated the cytotoxic effects of the c-Src inhibitor bosutinib, both in vitro and in vivo. The combination of sublethal doses of VPA and bosutinib led to massive apoptosis of colon cancer cells, irrespective of their genetic background. These results suggest that VPA may be employed as a positive modulator of bosutinib antitumor activity in colorectal cancer.

  19. Chicoric acid analogues as HIV-1 integrase inhibitors.

    PubMed

    Lin, Z; Neamati, N; Zhao, H; Kiryu, Y; Turpin, J A; Aberham, C; Strebel, K; Kohn, K; Witvrouw, M; Pannecouque, C; Debyser, Z; De Clercq, E; Rice, W G; Pommier, Y; Burke, T R

    1999-04-22

    The present study was undertaken to examine structural features of L-chicoric acid (3) which are important for potency against purified HIV-1 integrase and for reported cytoprotective effects in cell-based systems. Through a progressive series of analogues, it was shown that enantiomeric D-chicoric acid (4) retains inhibitory potency against purified integrase equal to its L-counterpart and further that removal of either one or both carboxylic functionalities results in essentially no loss of inhibitory potency. Additionally, while two caffeoyl moieties are required, attachment of caffeoyl groups to the central linking structure can be achieved via amide or mixed amide/ester linkages. More remarkable is the finding that blockage of the catechol functionality through conversion to tetraacetate esters results in almost no loss of potency, contingent on the presence of at least one carboxyl group on the central linker. Taken as a whole, the work has resulted in the identification of new integrase inhibitors which may be regarded as bis-caffeoyl derivatives of glycidic acid and amino acids such as serine and beta-aminoalanine. The present study also examined the reported ability of chicoric acid to exert cytoprotective effects in HIV-infected cells. It was demonstrated in target and cell-based assays that the chicoric acids do not significantly inhibit other targets associated with HIV-1 replication, including reverse transcription, protease function, NCp7 zinc finger function, or replication of virus from latently infected cells. In CEM cells, for both the parent chicoric acid and selected analogues, antiviral activity was observable under specific assay conditions and with high dependence on the multiplicity of viral infection. However, against HIV-1- and HIV-2-infected MT-4 cells, the chicoric acids and their tetraacetylated esters exhibited antiviral activity (50% effective concentration (EC50) ranging from 1.7 to 20 microM and 50% inhibitory concentration (IC50

  20. Class I HDACs are mediators of smoke-carcinogen induced stabilization of DNMT1 and serve as promising targets for chemoprevention of lung cancer

    PubMed Central

    Brodie, Seth A; Li, Ge; El-Kommos, Adam; Kang, Hyunseok; Ramalingam, Suresh S; Behera, Madhusmita; Gandhi, Khanjan; Kowalski, Jeanne; Sica, Gabriel L; Khuri, Fadlo R; Vertino, Paula M.; Brandes, Johann C

    2014-01-01

    DNA methylation is an early event in bronchial carcinogenesis and increased DNA methyltransferase (DNMT)1 protein expression is a crucial step in the oncogenic transformation of epithelia. Here, we investigate the role of class I histone deacetylases (HDACs) 1–3 in the stabilization of DNMT1 protein and as a potential therapeutic target for lung cancer chemoprevention. Long-term exposure of immortalized bronchial epithelial cells (HBEC-3KT) to low doses of tobacco-related carcinogens led to oncogenic transformation, increased HDAC expression, cell cycle independent increased DNMT1 stability and DNA hypermethylation. Overexpression of HDACs was associated with increased DNMT1 stability and knockdown of HDACs reduced DNMT1 protein levels and induced DNMT1 acetylation. This suggests a causal relationship among increased class I HDACs levels, upregulation of DNMT1 protein, and subsequent promoter hypermethylation. Targeting of class I HDACs with valproic acid (VPA) was associated with reduced HDAC expression and a profound reduction of DNMT1 protein level. Treatment of transformed bronchial epithelial cells with VPA resulted in reduced colony formation, demethylation of the aberrantly methylated SFRP2 promoter and de-repression of SFRP2 transcription. These data suggest that inhibition of HDAC activity may reverse or prevent carcinogen induced transformation. Finally, immunohistochemistry on human lung cancer specimens revealed a significant increase in DNMT1, HDAC1, HDAC2, and HDAC3 expression, supporting our hypotheses that class I HDACs are mediators of DNMT1 stability. In summary, our study provides evidence for an important role of class I HDACs in controlling the stability of DNMT1 and suggests that HDAC inhibition could be an attractive approach for lung cancer chemoprevention. PMID:24441677

  1. HDAC-mediated Deacetylation of NF-κB is Critical for Schwann cell Myelination

    PubMed Central

    Chen, Ying; Wang, Haibo; Yoon, Sung Ok; Xu, Xiaomei; Hottiger, Michael; Svaren, John; Nave, Klaus A.; Kim, Haesun A.; Olson, Eric N.; Lu, Q. Richard

    2011-01-01

    Schwann cell myelination is tightly regulated by timely expression of key transcriptional regulators that respond to specific environmental cues, yet molecular mechanisms underlying such a process are poorly understood. Here, we report that HDAC1/2-regulated acetylation state of NF-κB is critical in orchestrating the myelination program. Mice lacking HDAC1/2 exhibit severe dysmyelination with Schwann cell development arrested at the immature stage. We find that NF-κB p65 becomes heavily acetylated in HDAC1/2 mutants, inhibiting the expression of positive regulators of myelination, while inducing the expression of differentiation inhibitors. We observe that NF-κB protein complex switches its association with p300 to that with HDAC1/2 as Schwann cells differentiate. NF-κB and HDAC1/2 act coordinately to regulate the transcriptionally-linked chromatin state for Schwann cell myelination. Thus, our results reveal an HDAC-mediated developmental switch for controlling myelination in the peripheral nervous system. PMID:21423191

  2. Drug inhibition of HDAC3 and epigenetic control of differentiation in Apicomplexa parasites.

    PubMed

    Bougdour, Alexandre; Maubon, Danièle; Baldacci, Patricia; Ortet, Philippe; Bastien, Olivier; Bouillon, Anthony; Barale, Jean-Christophe; Pelloux, Hervé; Ménard, Robert; Hakimi, Mohamed-Ali

    2009-04-13

    Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although little is yet known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. We investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase inhibitor (HDACi). We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi's such as trichostatin A and the clinically relevant compound pyrimethamine. We identify T. gondii HDAC3 (TgHDAC3) as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (nonreplicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of approximately 370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDACi of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and, likely, other Apicomplexa.

  3. Drug inhibition of HDAC3 and epigenetic control of differentiation in Apicomplexa parasites

    PubMed Central

    Bougdour, Alexandre; Maubon, Danièle; Baldacci, Patricia; Ortet, Philippe; Bastien, Olivier; Bouillon, Anthony; Barale, Jean-Christophe; Pelloux, Hervé; Ménard, Robert

    2009-01-01

    Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although little is yet known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. We investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase inhibitor (HDACi). We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi's such as trichostatin A and the clinically relevant compound pyrimethamine. We identify T. gondii HDAC3 (TgHDAC3) as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (nonreplicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of ∼370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDACi of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and, likely, other Apicomplexa. PMID:19349466

  4. Amino acid sequence of winged bean (Psophocarpus tetragonolobus (L.) DC.) chymotrypsin inhibitor, WCI-3.

    PubMed

    Shibata, H; Hara, S; Ikenaka, T

    1988-10-01

    The complete amino acid sequence of winged bean chymotrypsin inhibitor 3 (WCI-3) was determined by the conventional methods. WCI-3 consisted of 183 amino acid residues, but was heterogeneous in the carboxyl terminal region owing to the loss of one to four carboxyl terminal amino acid residues. The sequence of WCI-3 was highly homologous with those of soybean trypsin inhibitor Tia, winged bean trypsin inhibitor WTI-1, and Erythrina latissima trypsin inhibitor DE-3. One of the reactive site peptide bonds of WCI-3 was identified as Leu(65)-Ser(66), which was located at the same position as those of the other Kunitz-family leguminous proteinase inhibitors.

  5. CRISPR screen identifies the NCOR/HDAC3 complex as a major suppressor of differentiation in rhabdomyosarcoma

    PubMed Central

    Phelps, Michael P.; Bailey, Jenna N.; Vleeshouwer-Neumann, Terra

    2016-01-01

    Dysregulated gene expression resulting from abnormal epigenetic alterations including histone acetylation and deacetylation has been demonstrated to play an important role in driving tumor growth and progression. However, the mechanisms by which specific histone deacetylases (HDACs) regulate differentiation in solid tumors remains unclear. Using pediatric rhabdomyosarcoma (RMS) as a paradigm to elucidate the mechanism blocking differentiation in solid tumors, we identified HDAC3 as a major suppressor of myogenic differentiation from a high-efficiency Clustered regularly interspaced short palindromic repeats (CRISPR)-based phenotypic screen of class I and II HDAC genes. Detailed characterization of the HDAC3-knockout phenotype in vitro and in vivo using a tamoxifen-inducible CRISPR targeting strategy demonstrated that HDAC3 deacetylase activity and the formation of a functional complex with nuclear receptor corepressors (NCORs) were critical in restricting differentiation in RMS. The NCOR/HDAC3 complex specifically functions by blocking myoblast determination protein 1 (MYOD1)-mediated activation of myogenic differentiation. Interestingly, there was also a transient up-regulation of growth-promoting genes upon initial HDAC3 targeting, revealing a unique cancer-specific response to the forced transition from a neoplastic state to terminal differentiation. Our study applied modifications of CRISPR/CRISPR-associated endonuclease 9 (Cas9) technology to interrogate the function of essential cancer genes and pathways and has provided insights into cancer cell adaptation in response to altered differentiation status. Because current pan-HDAC inhibitors have shown disappointing results in clinical trials of solid tumors, therapeutic targets specific to HDAC3 function represent a promising option for differentiation therapy in malignant tumors with dysregulated HDAC3 activity. PMID:27956629

  6. Deregulated expression of HDAC9 in B cells promotes development of lymphoproliferative disease and lymphoma in mice

    PubMed Central

    Gil, Veronica S.; Howell, Louise; Zhang, Jiyuan; Kim, Chae H.; Stengel, Sven; Vega, Francisco; Zelent, Arthur

    2016-01-01

    ABSTRACT Histone deacetylase 9 (HDAC9) is expressed in B cells, and its overexpression has been observed in B-lymphoproliferative disorders, including B-cell non-Hodgkin lymphoma (B-NHL). We examined HDAC9 protein expression and copy number alterations in primary B-NHL samples, identifying high HDAC9 expression among various lymphoma entities and HDAC9 copy number gains in 50% of diffuse large B-cell lymphoma (DLBCL). To study the role of HDAC9 in lymphomagenesis, we generated a genetically engineered mouse (GEM) model that constitutively expressed an HDAC9 transgene throughout B-cell development under the control of the immunoglobulin heavy chain (IgH) enhancer (Eμ). Here, we report that the Eμ-HDAC9 GEM model develops splenic marginal zone lymphoma and lymphoproliferative disease (LPD) with progression towards aggressive DLBCL, with gene expression profiling supporting a germinal center cell origin, as is also seen in human B-NHL tumors. Analysis of Eμ-HDAC9 tumors suggested that HDAC9 might contribute to lymphomagenesis by altering pathways involved in growth and survival, as well as modulating BCL6 activity and p53 tumor suppressor function. Epigenetic modifications play an important role in the germinal center response, and deregulation of the B-cell epigenome as a consequence of mutations and other genomic aberrations are being increasingly recognized as important steps in the pathogenesis of a variety of B-cell lymphomas. A thorough mechanistic understanding of these alterations will inform the use of targeted therapies for these malignancies. These findings strongly suggest a role for HDAC9 in B-NHL and establish a novel GEM model for the study of lymphomagenesis and, potentially, preclinical testing of therapeutic approaches based on histone deacetylase inhibitors. PMID:27799148

  7. The physiological roles of histone deacetylase (HDAC) 1 and 2: complex co-stars with multiple leading parts.

    PubMed

    Kelly, Richard D W; Cowley, Shaun M

    2013-06-01

    HDACs (histone deacetylases) 1 and 2 are ubiquitous long-lived proteins, which are often found together in three major multiprotein co-repressor complexes: Sin3, NuRD (nucleosome remodelling and deacetylation) and CoREST (co-repressor for element-1-silencing transcription factor). Although there is a burgeoning number of non-histone proteins within the acetylome, these complexes contain multiple DNA/chromatin-recognition motifs, which, in combination with transcription factors, target HDAC1/2 to chromatin. Their physiological roles should therefore be viewed within the framework of chromatin manipulation. Classically, HDACs were thought to be recruited predominantly by transcriptional repressors to facilitate local histone deacetylation and transcriptional repression. More recently, genome-wide assays have mapped HDAC1/2 and their associated proteins to transcriptionally active loci and have provided alternative context-specific functions, whereby their repressive functions are subtly exerted to balance transcriptional activation and repression. With a few significant exceptions (early embryogenesis, brain development), HDAC1 and HDAC2 are functionally redundant. In most mouse knockout studies, deletion of both enzymes is required in order to produce a substantial phenotype. HDAC1/2 activity has been implicated in the development of numerous tissue and cell types, including heart, skin, brain, B-cells and T-cells. A common feature in all HDAC1/2-knockout, -knockdown and small-molecule inhibitor studies is a reduction in cell proliferation. A generic role in cell cycle progression could be exploited in cancer cells, by blocking HDAC1/2 activity with small-molecule inhibitors, making them potentially useful drug targets.

  8. Sulfonyl Fluoride Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Alapafuja, Shakiru O.; Nikas, Spyros P.; Bharatan, Indu; Shukla, Vidyanand G.; Nasr, Mahmoud L.; Bowman, Anna L.; Zvonok, Nikolai; Li, Jing; Shi, Xiaomeng; Engen, John R.; Makriyannis, Alexandros

    2013-01-01

    Sulfonyl fluorides are known to inhibit esterases. Early work from our laboratory has identified hexadecyl sulfonylfluoride (AM374) as a potent in vitro and in vivo inhibitor of fatty acid amide hydrolase (FAAH). We now report on later generation sulfonyl fluoride analogs that exhibit potent and selective inhibition of FAAH. Using recombinant rat and human FAAH we show that 5-(4-hydroxyphenyl)pentanesulfonyl fluoride (AM3506) has similar inhibitory activity for both the rat and the human enzyme, while rapid dilution assays and mass spectrometry analysis suggest that the compound is a covalent modifier for FAAH and inhibits its action in an irreversible manner. Our SAR results are highlighted by molecular docking of key analogs. PMID:23083016

  9. cap alpha. -Alkenylphenones - A new class of acid corrosion inhibitors

    SciTech Connect

    Frenier, W.W.; Growcock, F.B.; Lopp, V.R. )

    1988-09-01

    In this paper, a new class of corrosion inhibitors for steel in strong HCI is described. When formulated with small amounts of surfactants, ..cap alpha..-Alkenylphenones provide excellent protection for oilfield steel in contact with strong HCI (up to 28%). The protection levels are similar to, and sometimes superior to, those provided by alkynols. In 15% HCI, benzylallyl alcohol (BAA) appears to be a common intermediate, i.e., in the acid after 24 h when any of the four different phenyl ketones are used. Poly(phenylvinyl ketone) (PPVK), which could form on the surface from reaction of absorbed BAA, was the major component of the thin surface film after corrosion tests with the four ketones.

  10. Proton pump inhibitors reduce the size and acidity of the acid pocket in the stomach.

    PubMed

    Rohof, Wout O; Bennink, Roelof J; Boeckxstaens, Guy E

    2014-07-01

    The gastric acid pocket is believed to be the reservoir from which acid reflux events originate. Little is known about how changes in position, size, and acidity of the acid pocket contribute to the therapeutic effect of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD). Thirty-six patients with GERD (18 not taking PPIs, 18 taking PPIs; 19 men; age, 55 ± 2.1 y) were analyzed by concurrent high-resolution manometry and pH-impedance monitoring after a standardized meal. The acid pocket was visualized using scintigraphy after intravenous administration of (99m)technetium-pertechnetate. The size of the acid pocket was measured and its position was determined, relative to the diaphragm, using radionuclide markers on a high-resolution manometry catheter. At the end of the study, the acid pocket was aspirated, and its pH level was measured. The number of reflux episodes was comparable between patients on and off PPIs, but the number of acid reflux episodes was reduced significantly in patients on PPIs. In patients on PPIs, the acid pocket was smaller and more frequently located below the diaphragm. The mean pH of the acid pocket was significantly lower in patients not taking PPIs (n = 6) than in those who were (n = 16) (0.9; range, 0.7-1.2 vs 4.0; range, 1.6-5.9; P < .001). The pH of acid pockets correlated significantly with the lowest pH values measured for refluxate (r = 0.72; P < .01). Based on analyses of acid pockets in patients with GERD, the acid pocket appears to be a reservoir from which reflux occurs when patients are receiving PPIs. PPIs might affect the size, acidity, or position of the acid pocket, which contributes to the efficacy in patients with GERD. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  11. Inhibitors of 20-hydroxyeicosatetraenoic acid reduce renal vasoconstrictor responsiveness.

    PubMed

    Quilley, J; Qiu, Y; Hirt, J

    2003-10-01

    20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P450-derived constrictor eicosanoid produced by the preglomerular vasculature where it contributes to regulation of tone. Removal of the tonic inhibitory influence of nitric oxide (NO) has been reported to increase renal 20-HETE release. Because inhibition of NO synthesis enhances responses to vasoconstrictor agents, we examined a contribution for increased 20-HETE generation. In the rat kidney perfused with Krebs' buffer, responses to U46619 (9,11-dideoxy-9alpha,11alpha-methanoepoxy PGF2alpha), a thromboxane A2 mimetic, were compared before and after 50 microM L-nitroarginine (L-NA) to inhibit NO synthase. L-NA raised perfusion pressure (PP) from 79 +/- 3 to 190 +/- 7 mm Hg and enhanced constrictor responsiveness to U46619. U46619 (10, 30, 100, and 300 ng) increased PP by 7 +/- 1, 17 +/- 2, 50 +/- 7, and 67 +/- 7 mm Hg, respectively, before L-NA and 15 +/- 1, 37 +/- 7, 68 +/- 10, and 85 +/- 11 mm Hg, respectively, after L-NA, which did not increase 20-HETE efflux from the kidney. Nonetheless, an inhibitor of omega-hydroxylase, dibromododecencyl methylsulfonimide (DDMS), which reduced 20-HETE release, normalized the enhanced responsiveness to U46619. When PP was elevated with phenylephrine, vasoconstrictor responses to U46619 were similarly enhanced, an effect that was also prevented by DDMS. DDMS and an antagonist of 20-HETE, 20-HEDE [20-hydroxyeicosa-6(Z), 15(Z)-dienoic acid], also reduced vasoconstrictor responses to U46619 in the absence of elevation of PP. Because 20-HETE inhibits K+ channels, we examined the effects of K+ channel inhibitors on vasoconstrictor responses and showed that both tetraethylammonium (TEA) and charybdotoxin enhanced renal vasoconstrictor responses to U46619. However, the inhibitory effects of 20-HEDE on vasoconstrictor responses remained after treatment with TEA. These results support a role for 20-HETE vasoconstrictor responses but suggest an action independent of K+ channels.

  12. Synthesis and HDAC inhibitory activity of isosteric thiazoline-oxazole largazole analogs.

    PubMed

    Guerra-Bubb, Jennifer M; Bowers, Albert A; Smith, William B; Paranal, Ronald; Estiu, Guillermina; Wiest, Olaf; Bradner, James E; Williams, Robert M

    2013-11-01

    The synthesis of an isosteric analog of the natural product and HDAC inhibitor largazole is described. The sulfur atom in the thizaole ring of the natural product has been replaced with an oxygen atom, constituting an oxazole ring. The biochemical activity and cytotoxicity of this species is described.

  13. Thermodynamics of Binding of Structurally Similar Ligands to Histone Deacetylase 8 Sheds Light on Challenges in the Rational Design of Potent and Isozyme-Selective Inhibitors of the Enzyme

    PubMed Central

    2015-01-01

    Among the different histone deacetylase (HDAC) isozymes, HDAC8 is the most highly malleable enzyme, and it exhibits the potential to accommodate structurally diverse ligands (albeit with moderate binding affinities) in its active site pocket. To probe the molecular basis of this feature, we performed detailed thermodynamic studies of the binding of structurally similar ligands, which differed with respect to the “cap”, “linker”, and “metal-binding” regions of the suberoylanilide hydroxamic acid (SAHA) pharmacophore, to HDAC8. The experimental data revealed that although the enthalpic (ΔH°) and entropic (ΔS°) changes for the binding of individual SAHA analogues to HDAC8 were substantially different, their binding free energies (ΔG°) were markedly similar, conforming to a strong enthalpy–entropy compensation effect. This effect was further observed in the temperature-dependent thermodynamics of binding of all SAHA analogues to the enzyme. Notably, in contrast to other metalloenzymes, our isothermal titration calorimetry experiments (performed in different buffers of varying ionization enthalpies) suggest that depending on the ligand, its zinc-binding group may or may not be deprotonated upon the binding to HDAC8. Furthermore, the heat capacity changes (ΔCp°) associated with the ligand binding to HDAC8 markedly differed from one SAHA analogue to the other, and such features could primarily be rationalized in light of the dynamic flexibility in the enzyme structure in conjunction with the reorganization of the active site resident water molecules. Arguments are presented that although the binding thermodynamic features described above would facilitate identification of weak to moderately tight-binding HDAC8 inhibitors (by a high-throughput and/or virtual screening of libraries of small molecules), they would pose major challenges for the structure-based rational design of highly potent and isozyme-selective inhibitors of human HDAC8. PMID:25407689

  14. Plant flavone apigenin inhibits HDAC and remodels chromatin to induce growth arrest and apoptosis in human prostate cancer cells: in vitro and in vivo study.

    PubMed

    Pandey, Mitali; Kaur, Parminder; Shukla, Sanjeev; Abbas, Ata; Fu, Pingfu; Gupta, Sanjay

    2012-12-01

    Apigenin (4',5,7,-trihydroxyflavone), an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms that have not been fully elucidated. Our studies indicate that apigenin-mediated growth inhibitory responses are due to inhibition of class I histone deacetylases (HDACs) in prostate cancer cells. Treatment of PC-3 and 22Rv1 cells with apigenin (20-40 µM) resulted in the inhibition of HDAC enzyme activity, specifically HDAC1 and HDAC3 at the protein and message level. Apigenin-mediated HDAC inhibition resulted in global histone H3 and H4 acetylation, as well as localized hyperacetylation of histone H3 on the p21/waf1 promoter. A corresponding increase was observed in p21/waf1 and bax protein and mRNA expression after apigenin exposure, consistent with the use of HDAC inhibitor, trichostatin A. The downstream events demonstrated cell cycle arrest and induction of apoptosis in both cancer cells. Studies of PC-3 xenografts in athymic nude mice further demonstrated that oral intake of apigenin at doses of 20 and 50 µg/mouse/d over an 8-wk period resulted in a marked reduction in tumor growth, HDAC activity, and HDAC1 and HDAC3 protein expression at both doses of apigenin. An increase in p21/waf1 expression was observed in apigenin-fed mice, compared to the control group. Furthermore, apigenin intake caused a significant decrease in bcl2 expression with concomitant increase in bax, shifting the bax/bcl2 ratio in favor of apoptosis. Our findings confirm for the first time that apigenin inhibits class I HDACs, particularly HDAC1 and HDAC3 and its exposure results in reversal of aberrant epigenetic events that promote malignancy. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

  15. Plant flavone apigenin inhibits HDAC and remodels chromatin to induce growth arrest and apoptosis in human prostate cancer cells: In vitro and in vivo study

    PubMed Central

    Pandey, Mitali; Kaur, Parminder; Shukla, Sanjeev; Abbas, Ata; Fu, Pingfu; Gupta, Sanjay

    2014-01-01

    Apigenin (4′,5,7,-trihydroxyflavone), an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms that have not been fully elucidated. Our studies indicate that apigenin-mediated growth inhibitory responses are due to inhibition of class I histone deacetylases (HDACs) in prostate cancer cells. Treatment of PC-3 and 22Rv1 cells with apigenin (20–40μM) resulted in the inhibition of HDAC enzyme activity, specifically HDAC1 and HDAC3 at the protein and message level. Apigenin-mediated HDAC inhibition resulted in global histone H3 and H4 acetylation, as well as localized hyperacetylation of histone H3 on the p21/waf1 promoter. A corresponding increase was observed in p21/waf1 and bax protein and mRNA expression after apigenin exposure, consistent with the use of HDAC inhibitor, trichostatin A. The downstream events demonstrated cell cycle arrest and induction of apoptosis in both cancer cells. Studies of PC-3 xenografts in athymic nude mice further demonstrated that oral intake of apigenin at doses of 20 and 50μg/mouse/day over an 8-week period resulted in a marked reduction in tumor growth, HDAC activity, and HDAC1 and HDAC3 protein expression at both doses of apigenin. An increase in p21/waf1 expression was observed in apigenin-fed mice, compared to the control group. Furthermore, apigenin intake caused a significant decrease in bcl2 expression with concomitant increase in bax, shifting the bax/bcl2 ratio in favor of apoptosis. Our findings confirm for the first time that apigenin inhibits class I HDACs, particularly HDAC1 and HDAC3 and its exposure results in reversal of aberrant epigenetic events that promote malignancy. PMID:22006862

  16. Rational combination treatment with histone deacetylase inhibitors and immunomodulatory drugs in multiple myeloma

    PubMed Central

    Hideshima, T; Cottini, F; Ohguchi, H; Jakubikova, J; Gorgun, G; Mimura, N; Tai, Y-T; Munshi, N C; Richardson, P G; Anderson, K C

    2015-01-01

    Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide (Len) and pomalidomide trigger anti-tumor activities in multiple myeloma (MM) by targetting cereblon and thereby impacting IZF1/3, c-Myc and IRF4. Histone deacetylase inhibitors (HDACi) also downregulate c-Myc. We therefore determined whether IMiDs with HDACi trigger significant MM cell growth inhibition by inhibiting or downregulating c-Myc. Combination treatment of Len with non-selective HDACi suberoylanilide hydroxamic acid or class-I HDAC-selective inhibitor MS275 induces synergic cytotoxicity, associated with downregulation of c-Myc. Unexpectedly, we observed that decreased levels of cereblon (CRBN), a primary target protein of IMiDs, was triggered by these agents. Indeed, sequential treatment of MM cells with MS275 followed by Len shows less efficacy than simultaneous treatment with this combination. Importantly ACY1215, an HDAC6 inhibitor with minimal effects on class-I HDACs, together with Len induces synergistic MM cytotoxicity without alteration of CRBN expression. Our results showed that only modest class-I HDAC inhibition is able to induce synergistic MM cytotoxicity in combination with Len. These studies may provide the framework for utilizing HDACi in combination with Len to both avoid CRBN downregulation and enhance anti-MM activities. PMID:25978432

  17. Rational combination treatment with histone deacetylase inhibitors and immunomodulatory drugs in multiple myeloma.

    PubMed

    Hideshima, T; Cottini, F; Ohguchi, H; Jakubikova, J; Gorgun, G; Mimura, N; Tai, Y-T; Munshi, N C; Richardson, P G; Anderson, K C

    2015-05-15

    Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide (Len) and pomalidomide trigger anti-tumor activities in multiple myeloma (MM) by targetting cereblon and thereby impacting IZF1/3, c-Myc and IRF4. Histone deacetylase inhibitors (HDACi) also downregulate c-Myc. We therefore determined whether IMiDs with HDACi trigger significant MM cell growth inhibition by inhibiting or downregulating c-Myc. Combination treatment of Len with non-selective HDACi suberoylanilide hydroxamic acid or class-I HDAC-selective inhibitor MS275 induces synergic cytotoxicity, associated with downregulation of c-Myc. Unexpectedly, we observed that decreased levels of cereblon (CRBN), a primary target protein of IMiDs, was triggered by these agents. Indeed, sequential treatment of MM cells with MS275 followed by Len shows less efficacy than simultaneous treatment with this combination. Importantly ACY1215, an HDAC6 inhibitor with minimal effects on class-I HDACs, together with Len induces synergistic MM cytotoxicity without alteration of CRBN expression. Our results showed that only modest class-I HDAC inhibition is able to induce synergistic MM cytotoxicity in combination with Len. These studies may provide the framework for utilizing HDACi in combination with Len to both avoid CRBN downregulation and enhance anti-MM activities.

  18. HDAC inhibition imparts beneficial transgenerational effects in Huntington's disease mice via altered DNA and histone methylation

    PubMed Central

    Jia, Haiqun; Morris, Charles D.; Williams, Roy M.; Loring, Jeanne F.; Thomas, Elizabeth A.

    2015-01-01

    Increasing evidence has demonstrated that epigenetic factors can profoundly influence gene expression and, in turn, influence resistance or susceptibility to disease. Epigenetic drugs, such as histone deacetylase (HDAC) inhibitors, are finding their way into clinical practice, although their exact mechanisms of action are unclear. To identify mechanisms associated with HDAC inhibition, we performed microarray analysis on brain and muscle samples treated with the HDAC1/3-targeting inhibitor, HDACi 4b. Pathways analyses of microarray datasets implicate DNA methylation as significantly associated with HDAC inhibition. Further assessment of DNA methylation changes elicited by HDACi 4b in human fibroblasts from normal controls and patients with Huntington’s disease (HD) using the Infinium HumanMethylation450 BeadChip revealed a limited, but overlapping, subset of methylated CpG sites that were altered by HDAC inhibition in both normal and HD cells. Among the altered loci of Y chromosome-linked genes, KDM5D, which encodes Lys (K)-specific demethylase 5D, showed increased methylation at several CpG sites in both normal and HD cells, as well as in DNA isolated from sperm from drug-treated male mice. Further, we demonstrate that first filial generation (F1) offspring from drug-treated male HD transgenic mice show significantly improved HD disease phenotypes compared with F1 offspring from vehicle-treated male HD transgenic mice, in association with increased Kdm5d expression, and decreased histone H3 Lys4 (K4) (H3K4) methylation in the CNS of male offspring. Additionally, we show that overexpression of Kdm5d in mutant HD striatal cells significantly improves metabolic deficits. These findings indicate that HDAC inhibitors can elicit transgenerational effects, via cross-talk between different epigenetic mechanisms, to have an impact on disease phenotypes in a beneficial manner. PMID:25535382

  19. Glutamine contributes to maintenance of mouse embryonic stem cell self-renewal through PKC-dependent downregulation of HDAC1 and DNMT1/3a

    PubMed Central

    Ryu, Jung Min; Lee, Sang Hun; Seong, Je Kyung; Han, Ho Jae

    2015-01-01

    Although glutamine (Gln) is not an essential amino acid, it is considered a critical substrate in many key metabolic processes that control a variety of physiological functions and are involved in regulating early embryonic development. Thus, we investigated the effect of Gln on regulation of mouse embryonic stem cell (mESC) self-renewal and related signaling pathways. Gln deprivation decreased Oct4 expression as well as expression of cell cycle regulatory proteins. However, Gln treatment retained the expression of cell cycle regulatory proteins and the Oct4 in mESCs, which were blocked by compound 968 (a glutaminase inhibitor). In addition, Gln stimulated PI3K/Akt pathway, which subsequently elicited PKCε translocation to membrane without an influx of intracellular Ca2+. Inhibition of Akt and PKC blocked Gln-induced Oct4 expression and proliferation. Gln also stimulated mTOR phosphorylation in a time-dependent manner, which abolished by PKC inhibition. Furthermore, Gln increased the cellular population of both Oct4 and bromodeoxyuridine positive cells, suggesting that Gln regulates self-renewal ability of mESCs. Gln induced a decrease in HDAC1, but not in HDAC2, which were blocked by PKC inhibitors. Gln treatment resulted in an increase in global histone acetylation and methylation. In addition, Gln significantly reduced methylation of the Oct4 promoter region through decrease in DNMT1 and DNMT3a expression, which were blocked by PKC and HDAC inhibitors. In conclusion, Gln stimulates mESC proliferation and maintains mESC undifferentiation status through transcription regulation via the Akt, PKCε, and mTOR signaling pathways. PMID:26375799

  20. Glutamine contributes to maintenance of mouse embryonic stem cell self-renewal through PKC-dependent downregulation of HDAC1 and DNMT1/3a.

    PubMed

    Ryu, Jung Min; Lee, Sang Hun; Seong, Je Kyung; Han, Ho Jae

    2015-01-01

    Although glutamine (Gln) is not an essential amino acid, it is considered a critical substrate in many key metabolic processes that control a variety of physiological functions and are involved in regulating early embryonic development. Thus, we investigated the effect of Gln on regulation of mouse embryonic stem cell (mESC) self-renewal and related signaling pathways. Gln deprivation decreased Oct4 expression as well as expression of cell cycle regulatory proteins. However, Gln treatment retained the expression of cell cycle regulatory proteins and the Oct4 in mESCs, which were blocked by compound 968 (a glutaminase inhibitor). In addition, Gln stimulated PI3K/Akt pathway, which subsequently elicited PKCϵ translocation to membrane without an influx of intracellular Ca(2+). Inhibition of Akt and PKC blocked Gln-induced Oct4 expression and proliferation. Gln also stimulated mTOR phosphorylation in a time-dependent manner, which abolished by PKC inhibition. Furthermore, Gln increased the cellular population of both Oct4 and bromodeoxyuridine positive cells, suggesting that Gln regulates self-renewal ability of mESCs. Gln induced a decrease in HDAC1, but not in HDAC2, which were blocked by PKC inhibitors. Gln treatment resulted in an increase in global histone acetylation and methylation. In addition, Gln significantly reduced methylation of the Oct4 promoter region through decrease in DNMT1 and DNMT3a expression, which were blocked by PKC and HDAC inhibitors. In conclusion, Gln stimulates mESC proliferation and maintains mESC undifferentiation status through transcription regulation via the Akt, PKCϵ, and mTOR signaling pathways.

  1. Kinetic method for the large-scale analysis of the binding mechanism of histone deacetylase inhibitors.

    PubMed

    Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

    2014-09-01

    Performing kinetic studies on protein ligand interactions provides important information on complex formation and dissociation. Beside kinetic parameters such as association rates and residence times, kinetic experiments also reveal insights into reaction mechanisms. Exploiting intrinsic tryptophan fluorescence a parallelized high-throughput Förster resonance energy transfer (FRET)-based reporter displacement assay with very low protein consumption was developed to enable the large-scale kinetic characterization of the binding of ligands to recombinant human histone deacetylases (HDACs) and a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes. For the binding of trichostatin A (TSA), suberoylanilide hydroxamic acid (SAHA), and two other SAHA derivatives to HDAH, two different modes of action, simple one-step binding and a two-step mechanism comprising initial binding and induced fit, were verified. In contrast to HDAH, all compounds bound to human HDAC1, HDAC6, and HDAC8 through a two-step mechanism. A quantitative view on the inhibitor-HDAC systems revealed two types of interaction, fast binding and slow dissociation. We provide arguments for the thesis that the relationship between quantitative kinetic and mechanistic information and chemical structures of compounds will serve as a valuable tool for drug optimization. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Pistagremic acid, a glucosidase inhibitor from Pistacia integerrima.

    PubMed

    Uddin, Ghias; Rauf, Abdur; Al-Othman, Abdulaziz M; Collina, Simona; Arfan, Muhammad; Ali, Gowhar; Khan, Inamullah

    2012-12-01

    Pistacia integerrima Stewart in traditionally used as folk remedy for various pathological conditions including diabetes. In order to identify the bioactive compound responsible for its folk use in diabetes, a phytochemical and biological study was conducted. Pistagremic acid (PA) was isolated from the dried galls extract of P. integerrima. Strong α-glucosidase inhibitory potential of PA was predicted using its molecular docking simulations against yeast α-glucosidase as a therapeutic target. Significant experimental α-glucosidase inhibitory activity of PA confirmed the computational predictions. PA showed potent enzyme inhibitory activity both against yeast (IC(50): 89.12±0.12μM) and rat intestinal (IC(50): 62.47±0.09μM) α-glucosidases. Interestingly, acarbose was found to be more than 12 times more potent an inhibitor against mammalian (rat intestinal) enzyme (having IC(50) value 62.47±0.09μM), as compared to the microbial (yeast) enzyme (with IC(50) value 780.21μM). Molecular binding mode was explored via molecular docking simulations, which revealed hydrogen bonding interactions between PA and important amino acid residues (Asp60, Arg69 and Asp 70 (3.11Å)), surrounding the catalytic site of the α-glucosidase. These interactions could be mainly responsible for their role in potent inhibitory activity of PA. PA has a strong potential to be further investigated as a new lead compound for better management of diabetes.

  3. Identification of Novel Functional Inhibitors of Acid Sphingomyelinase

    PubMed Central

    Trapp, Stefan; Pechmann, Stefanie; Friedl, Astrid; Reichel, Martin; Mühle, Christiane; Terfloth, Lothar; Groemer, Teja W.; Spitzer, Gudrun M.; Liedl, Klaus R.; Gulbins, Erich; Tripal, Philipp

    2011-01-01

    We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78%) compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66%) drugs licensed for medical use in humans. PMID:21909365

  4. Role of Acid and Weakly Acidic Reflux in Gastroesophageal Reflux Disease Off Proton Pump Inhibitor Therapy

    PubMed Central

    Sung, Hea Jung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

    2012-01-01

    Background/Aims Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. Methods We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. The characteristics of acid and weakly acidic reflux were evaluated. Symptomatic and asymptomatic reflux were compared according to GERD subtypes and individual symptoms. Results Forty-two patients (22 males, mean age 46 years) were diagnosed as GERD (17 erosive reflux disease, 9 pH(+) non-erosive reflux disease [NERD], 9 hypersensitive esophagus and 7 symptomatic NERD). A total of 1,725 reflux episodes were detected (855 acid [50%], 857 weakly acidic [50%] and 13 weakly alkaline reflux [< 1%]). Acid reflux was more frequently symptomatic and bolus clearance was longer compared with weakly acidic reflux. In terms of globus, weakly acidic reflux was more symptomatic. Symptomatic reflux was more frequently acid and mixed reflux; these associations were more pronounced in erosive reflux disease and symptomatic NERD. The perception of regurgitation was related to acid reflux, while that of globus was more related to weakly acidic reflux. Conclusions In patients not taking PPI, acid reflux was more frequently symptomatic and had longer bolus clearance. Symptomatic reflux was more frequently acid and mixed type; however, weakly acidic reflux was associated more with globus. These data suggest a role for impedance-pH data in the evaluation of globus. PMID:22837877

  5. Histone Deacetylase Inhibitors: Synthesis of Cyclic Tetrapeptides and their Triazole Analogues

    PubMed Central

    Singh, Erinprit K.; Nazarova, Lidia A.; Lapera, Stephanie A.; Alexander, Leslie D.

    2010-01-01

    Synthesis of nine macrocyclic peptide HDAC inhibitors and three triazole derivatives are described. HDAC inhibitory activity of these compounds against HeLa cell lysate is evaluated. The biological data demonstrates that incorporation of a triazole unit improves the HDAC inhibitory activity. PMID:20865132

  6. Histone deacetylases in monocyte/macrophage development, activation and metabolism: refining HDAC targets for inflammatory and infectious diseases.

    PubMed

    Das Gupta, Kaustav; Shakespear, Melanie R; Iyer, Abishek; Fairlie, David P; Sweet, Matthew J

    2016-01-01

    Macrophages have central roles in danger detection, inflammation and host defense, and consequently, these cells are intimately linked to most disease processes. Major advances in our understanding of the development and function of macrophages have recently come to light. For example, it is now clear that tissue-resident macrophages can be derived from either blood monocytes or through local proliferation of phagocytes that are originally seeded during embryonic development. Metabolic state has also emerged as a major control point for macrophage activation phenotypes. Herein, we review recent literature linking the histone deacetylase (HDAC) family of enzymes to macrophage development and activation, particularly in relation to these recent developments. There has been considerable interest in potential therapeutic applications for small molecule inhibitors of HDACs (HDACi), not only for cancer, but also for inflammatory and infectious diseases. However, the enormous range of molecular and cellular processes that are controlled by different HDAC enzymes presents a potential stumbling block to clinical development. We therefore present examples of how classical HDACs control macrophage functions, roles of specific HDACs in these processes and approaches for selective targeting of drugs, such as HDACi, to macrophages. Development of selective inhibitors of macrophage-expressed HDACs and/or selective delivery of pan HDACi to macrophages may provide avenues for enhancing efficacy of HDACi in therapeutic applications, while limiting unwanted side effects.

  7. Histone deacetylases in monocyte/macrophage development, activation and metabolism: refining HDAC targets for inflammatory and infectious diseases

    PubMed Central

    Das Gupta, Kaustav; Shakespear, Melanie R; Iyer, Abishek; Fairlie, David P; Sweet, Matthew J

    2016-01-01

    Macrophages have central roles in danger detection, inflammation and host defense, and conse