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Sample records for acid hdac inhibitor

  1. HDAC Inhibitors.

    PubMed

    Olzscha, Heidi; Bekheet, Mina E; Sheikh, Semira; La Thangue, Nicholas B

    2016-01-01

    Lysine acetylation in proteins is one of the most abundant posttranslational modifications in eukaryotic cells. The dynamic homeostasis of lysine acetylation and deacetylation is dictated by the action of histone acetyltransferases (HAT) and histone deacetylases (HDAC). Important substrates for HATs and HDACs are histones, where lysine acetylation generally leads to an open and transcriptionally active chromatin conformation. Histone deacetylation forces the compaction of the chromatin with subsequent inhibition of transcription and reduced gene expression. Unbalanced HAT and HDAC activity, and therefore aberrant histone acetylation, has been shown to be involved in tumorigenesis and progression of malignancy in different types of cancer. Therefore, the development of HDAC inhibitors (HDIs) as therapeutic agents against cancer is of great interest. However, treatment with HDIs can also affect the acetylation status of many other non-histone proteins which play a role in different pathways including angiogenesis, cell cycle progression, autophagy and apoptosis. These effects have led HDIs to become anticancer agents, which can initiate apoptosis in tumor cells. Hematological malignancies in particular are responsive to HDIs, and four HDIs have already been approved as anticancer agents. There is a strong interest in finding adequate biomarkers to predict the response to HDI treatment. This chapter provides information on how to assess HDAC activity in vitro and determine the potency of HDIs on different HDACs. It also gives information on how to analyze cellular markers following HDI treatment and to analyze tissue biopsies from HDI-treated patients. Finally, a protocol is provided on how to detect HDI sensitivity determinants in human cells, based on a pRetroSuper shRNA screen upon HDI treatment. PMID:27246222

  2. Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells.

    PubMed

    Göttlicher, M; Minucci, S; Zhu, P; Krämer, O H; Schimpf, A; Giavara, S; Sleeman, J P; Lo Coco, F; Nervi, C; Pelicci, P G; Heinzel, T

    2001-12-17

    Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

  3. Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells

    PubMed Central

    Göttlicher, Martin; Minucci, Saverio; Zhu, Ping; Krämer, Oliver H.; Schimpf, Annemarie; Giavara, Sabrina; Sleeman, Jonathan P.; Lo Coco, Francesco; Nervi, Clara; Pelicci, Pier Giuseppe; Heinzel, Thorsten

    2001-01-01

    Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

  4. Inside HDACs with more selective HDAC inhibitors.

    PubMed

    Roche, Joëlle; Bertrand, Philippe

    2016-10-01

    Inhibitors of histone deacetylases (HDACs) are nowadays part of the therapeutic arsenal mainly against cancers, with four compounds approved by the Food and Drug Administration. During the last five years, several groups have made continuous efforts to improve this class of compounds, designing more selective compounds or compounds with multiple capacities. After a survey of the HDAC biology and structures, this review summarizes the results of the chemists working in this field, and highlights when possible the behavior of the molecules inside their targets.

  5. 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. PMID:27374062

  6. Lactam based 7-amino suberoylamide hydroxamic acids as potent HDAC inhibitors.

    PubMed

    Taddei, Maurizio; Cini, Elena; Giannotti, Luca; Giannini, Giuseppe; Battistuzzi, Gianfranco; Vignola, Davide; Vesci, Loredana; Cabri, Walter

    2014-01-01

    A series of SAHA-like molecules were prepared introducing different lactam-carboxyamides in position 7 of the suberoylanilide skeleton. The activity against different HDAC isoforms was tested and the data compared with the corresponding linear products, without substituent in position 7. In general, this modification provided an effective reinforcement of in vitro activity. While the lactam size or the CO/NH group orientation did not strongly influence the inhibition, the contemporary modification of the suberoylamide fragment gave vary active variants in the lactam series, with compound 28 (ST8078AA1) that showed IC50 values between 2 and 10nM against all Class I HDAC isoforms, demonstrating it to be a large spectrum pan-inhibitor. This strong affinity with HDAC was also confirmed by the value of IC50=0.5μM against H460 cells, ranking 28 as one of the most potent HDAC inhibitors described so far. PMID:24345446

  7. 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

  8. 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.

  9. 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

  10. ANTIDEPRESSANT ACTIONS OF HDAC INHIBITORS

    PubMed Central

    Covington, Herbert E.; Maze, Ian; LaPlant, Quincey C.; Vialou, Vincent F.; Yoshinori, Ohnishi N.; Berton, Olivier; Fass, Dan M.; Renthal, William; Rush, Augustus J.; Wu, Emma Y.; Ghose, Subroto; Krishnan, Vaishnav; Russo, Scott J.; Tamminga, Carol; Haggarty, Stephen J.; Nestler, Eric J.

    2009-01-01

    Persistent symptoms of depression suggest the involvement of stable molecular adaptations in brain, which may be reflected at the level of chromatin remodeling. We find that chronic social defeat stress in mice causes a transient decrease, followed by a persistent increase, in levels of acetylated histone H3 in the nucleus accumbens, an important limbic brain region. This persistent increase in H3 acetylation is associated with decreased levels of histone deacetylase 2 (HDAC2) in the nucleus accumbens. Similar effects were observed in the nucleus accumbens of depressed humans studied postmortem. These changes in H3 acetylation and HDAC2 expression mediate long-lasting positive neuronal adaptations, since infusion of HDAC inhibitors into the nucleus accumbens, which increases histone acetylation, exerts robust antidepressant-like effects in the social defeat paradigm and other behavioral assays. HDAC inhibitor (MS-275) infusion also reverses the effects of chronic defeat stress on global patterns of gene expression in the nucleus accumbens, as determined by microarray analysis, with striking similarities to the effects of the standard antidepressant, fluoxetine. Stress-regulated genes whose expression is normalized selectively by MS-275 may provide promising targets for the future development of novel antidepressant treatments. Together, these findings provide new insight into the underlying molecular mechanisms of depression and antidepressant action, and support the antidepressant potential of HDAC inhibitors and perhaps other agents that act at the level of chromatin structure. PMID:19759294

  11. 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.

  12. 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.

  13. Synthesis and biological characterization of amidopropenyl hydroxamates as HDAC inhibitors.

    PubMed

    Thaler, Florian; Varasi, Mario; Colombo, Andrea; Boggio, Roberto; Munari, Davide; Regalia, Nickolas; Rozio, Marco G; Reali, Veronica; Resconi, Anna E; Mai, Antonello; Gagliardi, Stefania; Dondio, Giulio; Minucci, Saverio; Mercurio, Ciro

    2010-08-01

    A series of amidopropenyl hydroxamic acid derivatives were prepared as novel inhibitors of human histone deacetylases (HDACs). Several compounds showed potency at <100 nM in the HDAC inhibition assays, sub-micromolar IC(50) values in tests against three tumor cell lines, and remarkable stability in human and mouse microsomes was observed. Three representative compounds were selected for further characterization and submitted to a selectivity profile against a series of class I and class II HDACs as well as to preliminary in vivo pharmacokinetic (PK) experiments. Despite their high microsomal stability, the compounds showed medium-to-high clearance rates in in vivo PK studies as well as in rat and human hepatocytes, indicating that a major metabolic pathway is catalyzed by non-microsomal enzymes.

  14. Towards isozyme-selective HDAC inhibitors for interrogating disease.

    PubMed

    Gupta, Praveer; Reid, Robert C; Iyer, Abishek; Sweet, Matthew J; Fairlie, David P

    2012-01-01

    Histone deacetylase (HDAC) enzymes have emerged as promising targets for the treatment of a wide range of human diseases, including cancers, inflammatory and metabolic disorders, immunological, cardiovascular, and infectious diseases. At present, such applications are limited by the lack of selective inhibitors available for each of the eighteen HDAC enzymes, with most currently available HDAC inhibitors having broad-spectrum activity against multiple HDAC enzymes. Such broad-spectrum activity maybe useful in treating some diseases like cancers, but can be detrimental due to cytotoxic side effects that accompany prolonged treatment of chronic diseased states. Here we summarize progress towards the design and discovery of HDAC inhibitors that are selective for some of the eleven zinc-containing classical HDAC enzymes, and identify opportunities to use such isozyme-selective inhibitors as chemical probes for interrogating the biological roles of individual HDAC enzymes in diseases.

  15. 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

  16. 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

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

    PubMed

    Luckhurst, Christopher A; Breccia, Perla; Stott, Andrew J; Aziz, Omar; Birch, Helen L; Bürli, Roland W; Hughes, Samantha J; Jarvis, Rebecca E; Lamers, Marieke; Leonard, Philip M; Matthews, Kim L; McAllister, George; Pollack, Scott; Saville-Stones, Elizabeth; Wishart, Grant; Yates, Dawn; Dominguez, Celia

    2016-01-14

    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.

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

    PubMed

    Luckhurst, Christopher A; Breccia, Perla; Stott, Andrew J; Aziz, Omar; Birch, Helen L; Bürli, Roland W; Hughes, Samantha J; Jarvis, Rebecca E; Lamers, Marieke; Leonard, Philip M; Matthews, Kim L; McAllister, George; Pollack, Scott; Saville-Stones, Elizabeth; Wishart, Grant; Yates, Dawn; Dominguez, Celia

    2016-01-14

    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

  19. 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.

  20. 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

  1. Exploring the potential binding sites of some known HDAC inhibitors on some HDAC8 conformers by docking studies.

    PubMed

    Sixto-López, Yudibeth; Gómez-Vidal, José A; Correa-Basurto, José

    2014-08-01

    We describe the conformational behavior of histone deacetylase 8 (HDAC8) using molecular dynamics (MD) simulations. HDAC8 conformers were used for the docking studies using some known HDAC inhibitors (HDACi) suberoylanilide hydroxamic acid (SAHA), valproic acid (VPA), aroyl-pyrrole-hydroxy-amide (APHA-8) and tubacin to explore their interactions, binding modes, free energy values. The MD simulation show that HDAC8 make important surface changes at the catalytic site (CS) entrance as well as at two entrances locations in the 14-Å tunnel. In addition, we identify an alternate entrance to the 14-Å tunnel named adjacent to the catalytic site pocket (ACSP). By using docking studies, it was possible to elucidate the importance of hydrophobic and π-π interactions that are the most important for the ligand-HDAC8 complex structural stabilization. In conclusion, the ligand flexibility, molecular weight and chemical moieties (hydroxamic acid, aryl and aliphatic moieties) are the principal properties required to increase the binding affinity on HDAC8.

  2. 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

  3. 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

  4. HDAC inhibitors in experimental liver and kidney fibrosis

    PubMed Central

    2013-01-01

    Histone deacetylase (HDAC) inhibitors have been extensively studied in experimental models of cancer, where their inhibition of deacetylation has been proven to regulate cell survival, proliferation, differentiation and apoptosis. This in turn has led to the use of a variety of HDAC inhibitors in clinical trials. In recent years the applicability of HDAC inhibitors in other areas of disease has been explored, including the treatment of fibrotic disorders. Impaired wound healing involves the continuous deposition and cross-linking of extracellular matrix governed by myofibroblasts leading to diseases such as liver and kidney fibrosis; both diseases have high unmet medical needs which are a burden on health budgets worldwide. We provide an overview of the potential use of HDAC inhibitors against liver and kidney fibrosis using the current understanding of these inhibitors in experimental animal models and in vitro models of fibrosis. PMID:23281659

  5. 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

  6. The Class I HDAC inhibitor RGFP963 enhances consolidation of cued fear extinction

    PubMed Central

    Bowers, Mallory E.; Xia, Bing; Carreiro, Samantha

    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 inhibitor of HDAC3, does not significantly enhance consolidation of cued fear extinction. These data extend previous evidence that demonstrate the Class I HDACs play a role in the consolidation of long-term memory, suggesting that HDAC1 and/or HDAC2, but less likely HDAC3, may function as negative regulators of extinction retention. The development of specific HDAC inhibitors, such as RGFP963, will further illuminate the role of specific HDACs in various types of learning and memory. Moreover, HDAC inhibitors that enhance cued fear extinction may show translational promise for the treatment of fear-related disorders, including post-traumatic stress disorder (PTSD). PMID:25776040

  7. An HDAC inhibitor enhances cancer therapeutic efficiency of RNA polymerase III promoter-driven IDO shRNA.

    PubMed

    Yen, M-C; Weng, T-Y; Chen, Y-L; Lin, C-C; Chen, C-Y; Wang, C-Y; Chao, H-L; Chen, C-S; Lai, M-D

    2013-06-01

    Histone deacetylase (HDAC) inhibitors are used in treating certain human malignancies. Our laboratories demonstrated their capability in enhancing antitumor effect of DNA vaccine driven by an RNA polymerase II (RNA pol II) promoter. However, it is unknown whether HDAC inhibitors enhance the therapeutic short hairpin RNA (shRNA) expressed by an RNA polymerase III (RNA pol III) promoter. We investigated whether HDAC inhibitors augmented antitumor effect of indoleamine 2,3 dioxygenase (IDO) shRNA. HDAC inhibitor OSU-HDAC42 and suberoylanilide hydroxamic acid enhanced RNA pol III-driven U6 and H1 promoter activity in three different cell types in vitro: 293, NIH3T3 and dendritic cell line DC2.4. Subcutaneous injection of OSU-HDAC42 enhanced U6 and H1 promoter activity on abdominal skin of mice in vivo. Combination of IDO shRNA and OSU-HDAC42 increased antitumor effect of IDO shRNA in MBT-2 murine bladder tumor model. IDO shRNA induced tumor-infiltrating CD8⁺ and CD4⁺ T cells, whereas OSU-HDAC42 treatment induced tumor-infiltrating CD4⁺ T cells. Combination of OSU-HDAC42 and IDO shRNA further induced tumor-infiltrating natural killer cells and enhanced interferon-γ in lymphocytes, but suppressed interleukin (IL)-4 expression of lymphocytes. In addition, OSU-HDAC42 treatment did not alter mRNA expression of IL-12 and tumor necrosis factor-α. In conclusion, HDAC inhibitor OSU-HDAC42 may serve as adjuvant of the therapeutic shRNA expressed by an RNA pol III promoter.

  8. Dual-Mode HDAC Prodrug for Covalent Modification and Subsequent Inhibitor Release

    PubMed Central

    2016-01-01

    Histone deacetylase inhibitors (HDACi) target abnormal epigenetic states associated with a variety of pathologies, including cancer. Here, the development of a prodrug of the canonical broad-spectrum HDACi suberoylanilide hydroxamic acid (SAHA) is described. Although hydroxamic acids are utilized universally in the development of metalloenzyme inhibitors, they are considered to be poor pharmacophores with reduced activity in vivo. We developed a prodrug of SAHA by appending a promoiety, sensitive to thiols, to the hydroxamic acid warhead (termed SAHA-TAP). After incubation of SAHA-TAP with an HDAC, the thiol of a conserved HDAC cysteine residue becomes covalently tagged with the promoiety, initiating a cascade reaction that leads to the release of SAHA. Mass spectrometry and enzyme kinetics experiments validate that the cysteine residue is covalently appended with the TAP promoiety. SAHA-TAP demonstrates cytotoxicity activity against various cancer cell lines. This strategy represents an original prodrug design with a dual mode of action for HDAC inhibition. PMID:25974739

  9. Human HDAC isoform selectivity achieved via exploitation of the acetate release channel with structurally unique small molecule inhibitors

    SciTech Connect

    Whitehead, Lewis; Dobler, Markus R.; Radetich, Branko; Zhu, Yanyi; Atadja, Peter W.; Claiborne, Tavina; Grob, Jonathan E.; McRiner, Andrew; Pancost, Margaret R.; Patnaik, Anup; Shao, Wenlin; Shultz, Michael; Tichkule, Ritesh; Tommasi, Ruben A.; Vash, Brian; Wang, Ping; Stams, Travis

    2013-11-20

    Herein we report the discovery of a family of novel yet simple, amino-acid derived class I HDAC inhibitors that demonstrate isoform selectivity via access to the internal acetate release channel. Isoform selectivity criteria is discussed on the basis of X-ray crystallography and molecular modeling of these novel inhibitors bound to HDAC8, potentially revealing insights into the mechanism of enzymatic function through novel structural features revealed at the atomic level.

  10. Combining HDAC inhibitors with oncolytic virotherapy for cancer therapy

    PubMed Central

    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. PMID:27512681

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

    PubMed

    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.

  12. 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

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

    PubMed

    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

  14. Chemistry, Biology, and QSAR Studies of Substituted Biaryl Hydroxamates and Mercaptoacetamides as HDAC inhibitors - Nanomolar Potency Inhibitors of Pancreatic Cancer Cell Growth

    PubMed Central

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

    2009-01-01

    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 possibility to achieve some measure of isoform selectivity in the inhibition of the 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 nM potency in the HDAC inhibition assays and display micromolar to low nanomolar IC50 values when tested against five pancreatic cancer cell lines. The isoform selectivity of these ligands for the Class I HDACs (HDAC1-3 and 8) and Class IIb HDACs (HDAC6 and HDAC10) together with QSAR studies of their correlation with the lipophilicity are presented. Of particular interest is the HDAC6 selectivity of the mercaptoacetamides. PMID:18181121

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

    PubMed

    Whittle, Nigel; Singewald, Nicolas

    2014-04-01

    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.

  16. 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

  17. 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

  18. 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

  19. 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…

  20. HDAC inhibitor treatment of hepatoma cells induces both TRAIL-independent apoptosis and restoration of sensitivity to TRAIL.

    PubMed

    Pathil, Anita; Armeanu, Sorin; Venturelli, Sascha; Mascagni, Paolo; Weiss, Thomas S; Gregor, Michael; Lauer, Ulrich M; Bitzer, Michael

    2006-03-01

    Hepatocellular carcinoma (HCC) displays a striking resistance to chemotherapeutic drugs or innovative tumor cell apoptosis-inducing agents such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Recently, we found 2 histone deacetylase inhibitors (HDAC-I), valproic acid and ITF2357, exhibiting inherent therapeutic activity against HCC. In TRAIL-sensitive cancer cells, the mechanism of HDAC-I-induced cell death has been identified to be TRAIL-dependent by inducing apoptosis in an autocrine fashion. In contrast, in HCC-derived cells, a prototype of TRAIL-resistant tumor cells, we found a HDAC-I-mediated apoptosis that works independently of TRAIL and upregulation of death receptors or their cognate ligands. Interestingly, TRAIL resistance could be overcome by a combinatorial application of HDAC-I and TRAIL, increasing the fraction of apoptotic cells two- to threefold compared with HDAC-I treatment alone, whereas any premature HDAC-I withdrawal rapidly restored TRAIL resistance. Furthermore, a tumor cell-specific downregulation of the FLICE inhibitory protein (FLIP) was observed, constituting a new mechanism of TRAIL sensitivity restoration by HDAC-I. In contrast, FLIP levels in primary human hepatocytes (PHH) from different donors were upregulated by HDAC-I. Importantly, combination HDAC-I/TRAIL treatment did not induce any cytotoxicity in nonmalignant PHH. In conclusion, HDAC-I compounds, exhibiting a favorable in vivo profile and inherent activity against HCC cells, are able to selectively overcome the resistance of HCC cells toward TRAIL. Specific upregulation of intracellular FLIP protein levels in nonmalignant hepatocytes could enhance the therapeutic window for clinical applications of TRAIL, opening up a highly specific new treatment option for advanced HCC. PMID:16583461

  1. Dietary HDAC inhibitors: time to rethink weak ligands in cancer chemoprevention?

    PubMed Central

    H.Dashwood, Roderick; C.Myzak, Melinda; Ho, Emily

    2008-01-01

    There is growing interest in the various mechanisms that regulate chromatin remodeling, including modulation of histone deacetylase (HDAC) activities. Competitive HDAC inhibitors disrupt the cell cycle and/or induce apoptosis via de-repression of genes such as P21 and BAX, and cancer cells appear to be more sensitive than non-transformed cells to trichostatin A and related HDAC inhibitory compounds. This apparent selectivity of action in cancer cells makes HDAC inhibitors an attractive avenue for drug development. However, in the search for potent HDAC inhibitors with cancer therapeutic potential there has been a tendency to overlook or dismiss weak ligands that could prove effective in cancer prevention, including agents present in the human diet. Recent reports have described butyrate, diallyl disulfide and sulforaphane as HDAC inhibitors, and many other dietary agents will be probably discovered to attenuate HDAC activity. Here we discuss ‘pharmacologic’ agents that potently de-repress gene expression (e.g. during therapeutic intervention) versus dietary HDAC inhibitors that, as weak ligands, might subtly regulate the expression of genes involved in cell growth and apoptosis. An important question is the extent to which dietary HDAC inhibitors, and other dietary agents that affect gene expression via chromatin remodeling, modulate the expression of genes such as P21 and BAX so that cells can respond most effectively to external stimuli and toxic insults. PMID:16267097

  2. 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.

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

    PubMed Central

    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.

    2015-01-01

    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. PMID:26199860

  4. HDAC Inhibitors Target HDAC5, Upregulate MicroRNA-125a-5p, and Induce Apoptosis in Breast Cancer Cells

    PubMed Central

    Hsieh, Tsung-Hua; Hsu, Chia-Yi; Tsai, Cheng-Fang; Long, Cheng-Yu; Wu, Chin-Hu; Wu, Deng-Chyang; Lee, Jau-Nan; Chang, Wei-Chun; Tsai, Eing-Mei

    2015-01-01

    Histone deacetylase inhibitors (HDACi) are novel clinical anticancer drugs that inhibit HDAC gene expression and induce cell apoptosis in human cancers. Nevertheless, the detailed mechanism or the downstream HDAC targets by which HDACi mediates apoptosis in human breast cancer cells remains unclear. Here, we show that HDACi reduce tumorigenesis and induce intrinsic apoptosis of human breast cancer cells through the microRNA miR-125a-5p in vivo and in vitro. Intrinsic apoptosis was activated by the caspase 9/3 signaling pathway. In addition, HDACi mediated the expression of miR-125a-5p by activating RUNX3/p300/HDAC5 complex. Subsequently, miR-125a-5p silenced HDAC5 post-transcriptionally in the cells treated with HDACi. Thus, a regulatory loop may exist in human breast cancer cells involving miR-125a-5p and HDAC5 that is controlled by RUNX3 signaling. Silencing of miR-125a-5p and RUNX3 inhibited cancer progression and activated apoptosis, but silencing of HDAC5 had a converse effect. In conclusion, we demonstrate a possible new mechanism by which HDACi influence tumorigenesis and apoptosis via downregulation of miR-125a-5p expression. This study provides clinical implications in cancer chemotherapy using HDACi. PMID:25531695

  5. 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

  6. The promise and perils of HDAC inhibitors in neurodegeneration.

    PubMed

    Didonna, Alessandro; Opal, Puneet

    2015-01-01

    Histone deacetylases (HDACs) represent emerging therapeutic targets in the context of neurodegeneration. Indeed, pharmacologic inhibition of HDACs activity in the nervous system has shown beneficial effects in several preclinical models of neurological disorders. However, the translation of such therapeutic approach to clinics has been only marginally successful, mainly due to our still limited knowledge about HDACs physiological role particularly in neurons. Here, we review the potential benefits along with the risks of targeting HDACs in light of what we currently know about HDAC activity in the brain.

  7. The promise and perils of HDAC inhibitors in neurodegeneration

    PubMed Central

    Didonna, Alessandro; Opal, Puneet

    2015-01-01

    Histone deacetylases (HDACs) represent emerging therapeutic targets in the context of neurodegeneration. Indeed, pharmacologic inhibition of HDACs activity in the nervous system has shown beneficial effects in several preclinical models of neurological disorders. However, the translation of such therapeutic approach to clinics has been only marginally successful, mainly due to our still limited knowledge about HDACs physiological role particularly in neurons. Here, we review the potential benefits along with the risks of targeting HDACs in light of what we currently know about HDAC activity in the brain. PMID:25642438

  8. 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.

  9. 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

  10. 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

  11. 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

  12. Context-selective death of acute myeloid leukemia cells triggered by the novel hybrid retinoid-HDAC inhibitor MC2392.

    PubMed

    De Bellis, Floriana; Carafa, Vincenzo; Conte, Mariarosaria; Rotili, Dante; Petraglia, Francesca; Matarese, Filomena; Françoijs, Kees-Jan; Ablain, Julien; Valente, Sergio; Castellano, Rèmy; Goubard, Armelle; Collette, Yves; Mandoli, Amit; Martens, Joost H A; de Thé, Hugues; Nebbioso, Angela; Mai, Antonello; Stunnenberg, Hendrik G; Altucci, Lucia

    2014-04-15

    HDAC inhibitors (HDACi) are widely used in the clinic to sensitize tumorigenic cells for treatment with other anticancer compounds. The major drawback of HDACi is the broad inhibition of the plethora of HDAC-containing complexes. In acute promyelocytic leukemia (APL), repression by the PML-RARα oncofusion protein is mediated by an HDAC-containing complex that can be dissociated by pharmacologic doses of all trans retinoic acid (ATRA) inducing differentiation and cell death at the expense of side effects and recurrence. We hypothesized that the context-specific close physical proximity of a retinoid and HDACi-binding protein in the repressive PML-RARα-HDAC complex may permit selective targeting by a hybrid molecule of ATRA with a 2-aminoanilide tail of the HDAC inhibitor MS-275, yielding MC2392. We show that MC2392 elicits weak ATRA and essentially no HDACi activity in vitro or in vivo. Genome-wide epigenetic analyses revealed that in NB4 cells expressing PML-RARα, MC2392 induces changes in H3 acetylation at a small subset of PML-RARα-binding sites. RNA-seq reveals that MC2392 alters expression of a number of stress-responsive and apoptotic genes. Concordantly, MC2392 induced rapid and massive, caspase-8-dependent cell death accompanied by RIP1 induction and ROS production. Solid and leukemic tumors are not affected by MC2392, but expression of PML-RARα conveys efficient MC2392-induced cell death. Our data suggest a model in which MC2392 binds to the RARα moiety and selectively inhibits the HDACs resident in the repressive complex responsible for the transcriptional impairment in APLs. Our findings provide proof-of-principle of the concept of a context-dependent targeted therapy.

  13. HDAC Inhibition Modulates Cardiac PPARs and Fatty Acid Metabolism in Diabetic Cardiomyopathy.

    PubMed

    Lee, Ting-I; Kao, Yu-Hsun; Tsai, Wen-Chin; Chung, Cheng-Chih; Chen, Yao-Chang; Chen, Yi-Jen

    2016-01-01

    Peroxisome proliferator-activated receptors (PPARs) regulate cardiac glucose and lipid homeostasis. Histone deacetylase (HDAC) inhibitor has anti-inflammatory effects which may play a key role in modulating PPARs and fatty acid metabolism. The aim of this study was to investigate whether HDAC inhibitor, MPT0E014, can modulate myocardial PPARs, inflammation, and fatty acid metabolism in diabetes mellitus (DM) cardiomyopathy. Electrocardiography, echocardiography, and western blotting were used to evaluate the electrophysiological activity, cardiac structure, fatty acid metabolism, inflammation, and PPAR isoform expressions in the control and streptozotocin-nicotinamide-induced DM rats with or without MPT0E014. Compared to control, DM and MPT0E014-treated DM rats had elevated blood glucose levels and lower body weights. However, MPT0E014-treated DM and control rats had smaller left ventricular end-diastolic diameter and shorter QT interval than DM rats. The control and MPT0E014-treated DM rats had greater cardiac PPAR-α and PPAR-δ protein expressions, but less cardiac PPAR-γ than DM rats. Moreover, control and MPT0E014-treated DM rats had lower concentrations of 5' adenosine monophosphate-activated protein kinase 2α, PPAR-γ coactivator 1α, phosphorylated acetyl CoA carboxylase, cluster of differentiation 36, diacylglycerol acyltransferase 1 (DGAT1), DGAT2, tumor necrosis factor-α, and interleukin-6 protein than DM rats. HDAC inhibition significantly attenuated DM cardiomyopathy through modulation of cardiac PPARS, fatty acid metabolism, and proinflammatory cytokines. PMID:27446205

  14. Pyridine hydroxamic acids are specific anti-HCV agents affecting HDAC6.

    PubMed

    Kozlov, Maxim V; Kleymenova, Alla A; Romanova, Lyudmila I; Konduktorov, Konstantin A; Kamarova, Kamila A; Smirnova, Olga A; Prassolov, Vladimir S; Kochetkov, Sergey N

    2015-06-01

    Recently we reported benzohydroxamic acids (BHAs) as potent and selective inhibitors of hepatitis C virus (HCV) replicon propagation. In this work 12 pyridine hydroxamic acids (PHAs) were synthesized and tested in full-genome replicon assay. It was found that PHAs possessed very similar anti-HCV properties compared to BHAs. Both classes of hydroxamic acids caused hyperacetylation of α-tubulin pointing to inhibition of histone deacetylase 6 (HDAC6) as part of their antiviral activity. The tested compounds did not inhibit the growth of poliovirus, displaying high selectivity against HCV.

  15. Combination therapy for hepatocellular carcinoma: Additive preclinical efficacy of the HDAC inhibitor panobinostat with sorafenib

    PubMed Central

    Lachenmayer, Anja; Toffanin, Sara; Cabellos, Laia; Alsinet, Clara; Hoshida, Yujin; Villanueva, Augusto; Minguez, Beatriz; Tsai, Hung-Wen; Ward, Stephen C.; Thung, Swan; Friedman, Scott L.; Llovet, Josep M.

    2012-01-01

    Background & Aims Hepatocellular carcinoma (HCC) is a heterogeneous cancer in which sorafenib is the only approved systemic therapy. Histone deacetylases (HDAC) are commonly dysregulated in cancer and therefore represent promising targets for therapies, however their role in HCC pathogenesis is still unknown. We analyzed the expression of 11 HDACs in human HCCs and assessed the efficacy of the pan-HDAC inhibitor panobinostat alone and in combination with sorafenib in preclinical models of liver cancer. Methods Gene expression and copy number changes were analyzed in a cohort of 334 human HCCs, while the effects of panobinostat and sorafenib were evaluated in 3 liver cancer cell lines and a murine xenograft model. Results Aberrant HDAC expression was identified and validated in 91 and 243 HCCs, respectively. Upregulation of HDAC3 and 5 mRNAs were significantly correlated with DNA copy number gains. Inhibiting HDACs with panobinostat led to strong anti-tumoral effects in vitro and vivo, enhanced by the addition of sorafenib. Cell viability and proliferation declined, while apoptosis and autophagy increased. Panobinostat increased Histone H3 and HSP90 acetylation, downregulated BIRC5 (survivin) and upregulated CDH1. Combination therapy with panobinostat and sorafenib significantly decreased vessel density, and most significantly decreased tumor volume and increased survival in HCC xenografts. Conclusions Aberrant expression of several HDACs and copy number gains of HDAC3 and HDAC5 occur in HCC. Treatment with panobinostat combined with sorafenib demonstrated the highest preclinical efficacy in HCC models, providing the rationale for clinical studies with this novel combination. PMID:22322234

  16. 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

  17. Histone modifiers and marks define heterogeneous groups of colorectal carcinomas and affect responses to HDAC inhibitors in vitro

    PubMed Central

    Lutz, Lisa; Fitzner, Ingrid Coutiño; Ahrens, Theresa; Geißler, Anna-Lena; Makowiec, Frank; Hopt, Ulrich T; Bogatyreva, Lioudmila; Hauschke, Dieter; Werner, Martin; Lassmann, Silke

    2016-01-01

    Little is known about histone modifiers and histone marks in colorectal cancers (CRC). The present study therefore addressed the role of histone acetylation and histone deacetylases (HDAC) in CRCs in situ and in vitro. Immunohistochemistry of primary CRCs (n=47) revealed that selected histone marks were frequently present (H3K4me3: 100%; H3K9me3: 77%; H3K9ac: 75%), partially displayed intratumoral heterogeneity (H3K9me3; H3K9ac) and were significantly linked to higher pT category (H3K9me3: p=0.023; H3K9ac: p=0.028). Furthermore, also HDAC1 (62%), HDAC2 (100%) and HDAC3 (72%) expression was frequent, revealing four CRC types: cases expressing 1) HDAC1, HDAC2 and HDAC3 (49%), 2) HDAC2 and HDAC3 (30%), 3) HDAC1 and HDAC2 (10.5%) and 4) exclusively HDAC2 (10.5%). Correlation to clinico-pathological parameters (pT, pN, G, MSI status) revealed that heterogeneous HDAC1 expression correlated with lymph node status (p=0.012). HDAC expression in situ was partially reflected by six CRC cell lines, with similar expression of all three HDACs (DLD1, LS174T), preferential HDAC2 and HDAC3 expression (SW480, Caco2) or lower HDAC2 and HDAC3 expression (HCT116, HT29). HDAC activity was variably higher in HCT116, HT29, DLD1 and SW480 compared to LS174T and Caco2 cells. Treatment with broad (SAHA) and specific (MS-275; FK228) HDAC inhibitors (HDACi) caused loss of cell viability in predominantly MSIpositive CRC cells (HCT116, LS174T, DLD1; SAHA, MS-275 and in part FK228). In contrast, MSI-negative CRC cells (Caco2, HT29, SW480) were resistant, except for high doses of FK228 (Caco2, HT29). Cell viability patterns were not linked to different efficacies of HDACi on reduction of HDAC activity or histone acetylation, p21 expression and/or induction of DNA damage (γH2A-X levels). In summary, this study reveals inter- and intra-tumoral heterogeneity of histone marks and HDAC expression in CRCs. This is reflected by diverse HDACi responses in vitro, which do not follow known modes of action

  18. Histone modifiers and marks define heterogeneous groups of colorectal carcinomas and affect responses to HDAC inhibitors in vitro.

    PubMed

    Lutz, Lisa; Fitzner, Ingrid Coutiño; Ahrens, Theresa; Geißler, Anna-Lena; Makowiec, Frank; Hopt, Ulrich T; Bogatyreva, Lioudmila; Hauschke, Dieter; Werner, Martin; Lassmann, Silke

    2016-01-01

    Little is known about histone modifiers and histone marks in colorectal cancers (CRC). The present study therefore addressed the role of histone acetylation and histone deacetylases (HDAC) in CRCs in situ and in vitro. Immunohistochemistry of primary CRCs (n=47) revealed that selected histone marks were frequently present (H3K4me3: 100%; H3K9me3: 77%; H3K9ac: 75%), partially displayed intratumoral heterogeneity (H3K9me3; H3K9ac) and were significantly linked to higher pT category (H3K9me3: p=0.023; H3K9ac: p=0.028). Furthermore, also HDAC1 (62%), HDAC2 (100%) and HDAC3 (72%) expression was frequent, revealing four CRC types: cases expressing 1) HDAC1, HDAC2 and HDAC3 (49%), 2) HDAC2 and HDAC3 (30%), 3) HDAC1 and HDAC2 (10.5%) and 4) exclusively HDAC2 (10.5%). Correlation to clinico-pathological parameters (pT, pN, G, MSI status) revealed that heterogeneous HDAC1 expression correlated with lymph node status (p=0.012). HDAC expression in situ was partially reflected by six CRC cell lines, with similar expression of all three HDACs (DLD1, LS174T), preferential HDAC2 and HDAC3 expression (SW480, Caco2) or lower HDAC2 and HDAC3 expression (HCT116, HT29). HDAC activity was variably higher in HCT116, HT29, DLD1 and SW480 compared to LS174T and Caco2 cells. Treatment with broad (SAHA) and specific (MS-275; FK228) HDAC inhibitors (HDACi) caused loss of cell viability in predominantly MSIpositive CRC cells (HCT116, LS174T, DLD1; SAHA, MS-275 and in part FK228). In contrast, MSI-negative CRC cells (Caco2, HT29, SW480) were resistant, except for high doses of FK228 (Caco2, HT29). Cell viability patterns were not linked to different efficacies of HDACi on reduction of HDAC activity or histone acetylation, p21 expression and/or induction of DNA damage (γH2A-X levels). In summary, this study reveals inter- and intra-tumoral heterogeneity of histone marks and HDAC expression in CRCs. This is reflected by diverse HDACi responses in vitro, which do not follow known modes of action

  19. The SCFA butyrate stimulates the epithelial production of retinoic acid via inhibition of epithelial HDAC.

    PubMed

    Schilderink, Ronald; Verseijden, Caroline; Seppen, Jurgen; Muncan, Vanesa; van den Brink, Gijs R; Lambers, Tim T; van Tol, Eric A; de Jonge, Wouter J

    2016-06-01

    In the intestinal mucosa, retinoic acid (RA) is a critical signaling molecule. RA is derived from dietary vitamin A (retinol) through conversion by aldehyde dehydrogenases (aldh). Reduced levels of short-chain fatty acids (SCFAs) are associated with pathological microbial dysbiosis, inflammatory disease, and allergy. We hypothesized that SCFAs contribute to mucosal homeostasis by enhancing RA production in intestinal epithelia. With the use of human and mouse epithelial cell lines and primary enteroids, we studied the effect of SCFAs on the production of RA. Functional RA conversion was analyzed by Adlefluor activity assays. Butyrate (0-20 mM), in contrast to other SCFAs, dose dependently induced aldh1a1 or aldh1a3 transcript expression and increased RA conversion in human and mouse epithelial cells. Epithelial cell line data were replicated in intestinal organoids. In these organoids, butyrate (2-5 mM) upregulated aldh1a3 expression (36-fold over control), whereas aldh1a1 was not significantly affected. Butyrate enhanced maturation markers (Mucin-2 and villin) but did not consistently affect stemness markers or other Wnt target genes (lgr5, olfm4, ascl2, cdkn1). In enteroids, the stimulation of RA production by SCFA was mimicked by inhibitors of histone deacetylase 3 (HDAC3) but not by HDAC1/2 inhibitors nor by agonists of butyrate receptors G-protein-coupled receptor (GPR)43 or GPR109A, indicating that butyrate stimulates RA production via HDAC3 inhibition. We conclude that the SCFA butyrate inhibits HDAC3 and thereby supports epithelial RA production. PMID:27151945

  20. HDAC Inhibition Modulates Cardiac PPARs and Fatty Acid Metabolism in Diabetic Cardiomyopathy

    PubMed Central

    Lee, Ting-I; Tsai, Wen-Chin; Chung, Cheng-Chih; Chen, Yao-Chang; Chen, Yi-Jen

    2016-01-01

    Peroxisome proliferator-activated receptors (PPARs) regulate cardiac glucose and lipid homeostasis. Histone deacetylase (HDAC) inhibitor has anti-inflammatory effects which may play a key role in modulating PPARs and fatty acid metabolism. The aim of this study was to investigate whether HDAC inhibitor, MPT0E014, can modulate myocardial PPARs, inflammation, and fatty acid metabolism in diabetes mellitus (DM) cardiomyopathy. Electrocardiography, echocardiography, and western blotting were used to evaluate the electrophysiological activity, cardiac structure, fatty acid metabolism, inflammation, and PPAR isoform expressions in the control and streptozotocin-nicotinamide-induced DM rats with or without MPT0E014. Compared to control, DM and MPT0E014-treated DM rats had elevated blood glucose levels and lower body weights. However, MPT0E014-treated DM and control rats had smaller left ventricular end-diastolic diameter and shorter QT interval than DM rats. The control and MPT0E014-treated DM rats had greater cardiac PPAR-α and PPAR-δ protein expressions, but less cardiac PPAR-γ than DM rats. Moreover, control and MPT0E014-treated DM rats had lower concentrations of 5′ adenosine monophosphate-activated protein kinase 2α, PPAR-γ coactivator 1α, phosphorylated acetyl CoA carboxylase, cluster of differentiation 36, diacylglycerol acyltransferase 1 (DGAT1), DGAT2, tumor necrosis factor-α, and interleukin-6 protein than DM rats. HDAC inhibition significantly attenuated DM cardiomyopathy through modulation of cardiac PPARS, fatty acid metabolism, and proinflammatory cytokines. PMID:27446205

  1. 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.

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

    PubMed Central

    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

  3. 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

  4. 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.

  5. 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

  6. Fragment based G-QSAR and molecular dynamics based mechanistic simulations into hydroxamic-based HDAC inhibitors against spinocerebellar ataxia.

    PubMed

    Sinha, Siddharth; Tyagi, Chetna; Goyal, Sukriti; Jamal, Salma; Somvanshi, Pallavi; Grover, Abhinav

    2016-10-01

    Expansion of polyglutamine (CAG) triplets within the coding gene ataxin 2 results in transcriptional repression, forming the molecular basis of the neurodegenerative disorder named spinocerebellar ataxia type-2 (SCA2). HDAC inhibitors (HDACi) have been elements of great interest in polyglutamine disorders such as Huntington's and Ataxia's. In this study, we have selected hydroxamic acid derivatives as HDACi and performed fragment-based G-QSAR, molecular docking studies and molecular dynamics simulations for elucidating the dynamic mode of action of HDACi with His-Asp catalytic dyad of HDAC4. The model was statistically validated to establish its predictive robustness. The model was statistically significant with r(2) value of .6297, cross-validated co-relation coefficient q(2) value of .5905 and pred_r(2) (predicted square co-relation coefficient) value of .85. An F-test value of 56.11 confirms absolute robustness of the model. Two combinatorial libraries comprising of 3180 compounds were created with hydroxamate moiety as the template and their pIC50 activities were predicted based on the G-QSAR model. The combinatorial library created was screened on the basis of predicted activity (pIC50), with two resultant top scoring compounds, HIC and DHC. The interaction of the compounds with His-Asp dyad in terms of H-bond interactions with His802, Asp840, Pro942, and Gly975 residues of HDAC4 was evaluated by docking and 20 ns long molecular dynamics simulations. This study provides valuable leads for structural substitutions required for hydroxamate moiety to exhibit enhanced inhibitory activity against HDAC4. The reported compounds demonstrated good binding and thus can be considered as potent therapeutic leads against ataxia. PMID:26510381

  7. Fragment based G-QSAR and molecular dynamics based mechanistic simulations into hydroxamic-based HDAC inhibitors against spinocerebellar ataxia.

    PubMed

    Sinha, Siddharth; Tyagi, Chetna; Goyal, Sukriti; Jamal, Salma; Somvanshi, Pallavi; Grover, Abhinav

    2016-10-01

    Expansion of polyglutamine (CAG) triplets within the coding gene ataxin 2 results in transcriptional repression, forming the molecular basis of the neurodegenerative disorder named spinocerebellar ataxia type-2 (SCA2). HDAC inhibitors (HDACi) have been elements of great interest in polyglutamine disorders such as Huntington's and Ataxia's. In this study, we have selected hydroxamic acid derivatives as HDACi and performed fragment-based G-QSAR, molecular docking studies and molecular dynamics simulations for elucidating the dynamic mode of action of HDACi with His-Asp catalytic dyad of HDAC4. The model was statistically validated to establish its predictive robustness. The model was statistically significant with r(2) value of .6297, cross-validated co-relation coefficient q(2) value of .5905 and pred_r(2) (predicted square co-relation coefficient) value of .85. An F-test value of 56.11 confirms absolute robustness of the model. Two combinatorial libraries comprising of 3180 compounds were created with hydroxamate moiety as the template and their pIC50 activities were predicted based on the G-QSAR model. The combinatorial library created was screened on the basis of predicted activity (pIC50), with two resultant top scoring compounds, HIC and DHC. The interaction of the compounds with His-Asp dyad in terms of H-bond interactions with His802, Asp840, Pro942, and Gly975 residues of HDAC4 was evaluated by docking and 20 ns long molecular dynamics simulations. This study provides valuable leads for structural substitutions required for hydroxamate moiety to exhibit enhanced inhibitory activity against HDAC4. The reported compounds demonstrated good binding and thus can be considered as potent therapeutic leads against ataxia.

  8. Histone Deacetylase (HDAC) Inhibitor Kinetic Rate Constants Correlate with Cellular Histone Acetylation but Not Transcription and Cell Viability

    PubMed Central

    Lauffer, Benjamin E. L.; Mintzer, Robert; Fong, Rina; Mukund, Susmith; Tam, Christine; Zilberleyb, Inna; Flicke, Birgit; Ritscher, Allegra; Fedorowicz, Grazyna; Vallero, Roxanne; Ortwine, Daniel F.; Gunzner, Janet; Modrusan, Zora; Neumann, Lars; Koth, Christopher M.; Lupardus, Patrick J.; Kaminker, Joshua S.; Heise, Christopher E.; Steiner, Pascal

    2013-01-01

    Histone deacetylases (HDACs) are critical in the control of gene expression, and dysregulation of their activity has been implicated in a broad range of diseases, including cancer, cardiovascular, and neurological diseases. HDAC inhibitors (HDACi) employing different zinc chelating functionalities such as hydroxamic acids and benzamides have shown promising results in cancer therapy. Although it has also been suggested that HDACi with increased isozyme selectivity and potency may broaden their clinical utility and minimize side effects, the translation of this idea to the clinic remains to be investigated. Moreover, a detailed understanding of how HDACi with different pharmacological properties affect biological functions in vitro and in vivo is still missing. Here, we show that a panel of benzamide-containing HDACi are slow tight-binding inhibitors with long residence times unlike the hydroxamate-containing HDACi vorinostat and trichostatin-A. Characterization of changes in H2BK5 and H4K14 acetylation following HDACi treatment in the neuroblastoma cell line SH-SY5Y revealed that the timing and magnitude of histone acetylation mirrored both the association and dissociation kinetic rates of the inhibitors. In contrast, cell viability and microarray gene expression analysis indicated that cell death induction and changes in transcriptional regulation do not correlate with the dissociation kinetic rates of the HDACi. Therefore, our study suggests that determining how the selective and kinetic inhibition properties of HDACi affect cell function will help to evaluate their therapeutic utility. PMID:23897821

  9. Reversal of glucose intolerance in rat offspring exposed to ethanol before birth through reduction of nuclear skeletal muscle HDAC expression by the bile acid TUDCA

    PubMed Central

    Yao, Xing‐Hai; Nguyen, Khanh H.; Nyomba, B. L. Grégoire

    2014-01-01

    Abstract Prenatal ethanol exposure causes cellular stress, insulin resistance, and glucose intolerance in adult offspring, with increased gluconeogenesis and reduced muscle glucose transporter‐4 (glut4) expression. Impaired insulin activation of Akt and nuclear translocation of histone deacetylases (HDACs) in the liver partly explain increased gluconeogenesis. The mechanism for the reduced glut4 is unknown. Pregnant rats were gavaged with ethanol over the last week of gestation and adult female offspring were studied. Some ethanol exposed offspring was treated with tauroursodeoxycholic acid (TUDCA) for 3 weeks. All these rats underwent intraperitoneal glucose tolerance and insulin tolerance tests. The expression of glut4, HDACs, and markers of endoplasmic reticulum (ER) unfolded protein response (XBP1, CHOP, ATF6) was examined in the gastrocnemius muscle fractions, and in C2C12 muscle cells cultured with ethanol, TUDCA, and HDAC inhibitors. Non‐TUDCA‐treated rats exposed to prenatal ethanol were insulin resistant and glucose intolerant with reduced muscle glut4 expression, increased ER marker expression, and increased nuclear HDACs, whereas TUDCA‐treated rats had normal insulin sensitivity and glucose tolerance with normal glut4 expression, ER marker expression, and HDAC levels. In C2C12 cells, ethanol reduced glut4 expression, but increased ER makers. While TUDCA restored glut4 and ER markers to control levels and HDAC inhibition rescued glut4 expression, HDAC inhibition had no effect on ER markers. The increase in nuclear HDAC levels consequent to prenatal ethanol exposure reduces glut4 expression in adult rat offspring, and this HDAC effect is independent of ER unfolded protein response. HDAC inhibition by TUDCA restores glut4 expression, with improvement in insulin sensitivity and glucose tolerance. PMID:25538147

  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. PMID:27377864

  11. Amino acid starvation induces reactivation of silenced transgenes and latent HIV-1 provirus via down-regulation of histone deacetylase 4 (HDAC4).

    PubMed

    Palmisano, Ilaria; Della Chiara, Giulia; D'Ambrosio, Rosa Lucia; Huichalaf, Claudia; Brambilla, Paola; Corbetta, Silvia; Riba, Michela; Piccirillo, Rosanna; Valente, Sergio; Casari, Giorgio; Mai, Antonello; Martinelli Boneschi, Filippo; Gabellini, Davide; Poli, Guido; Schiaffino, Maria Vittoria

    2012-08-21

    The epigenetic silencing of exogenous transcriptional units integrated into the genome represents a critical problem both for long-term gene therapy efficacy and for the eradication of latent viral infections. We report here that limitation of essential amino acids, such as methionine and cysteine, causes selective up-regulation of exogenous transgene expression in mammalian cells. Prolonged amino acid deprivation led to significant and reversible increase in the expression levels of stably integrated transgenes transcribed by means of viral or human promoters in HeLa cells. This phenomenon was mediated by epigenetic chromatin modifications, because histone deacetylase (HDAC) inhibitors reproduced starvation-induced transgene up-regulation, and transcriptome analysis, ChIP, and pharmacological and RNAi approaches revealed that a specific class II HDAC, namely HDAC4, plays a critical role in maintaining the silencing of exogenous transgenes. This mechanism was also operational in cells chronically infected with HIV-1, the etiological agent of AIDS, in a latency state. Indeed, both amino acid starvation and pharmacological inhibition of HDAC4 promoted reactivation of HIV-1 transcription and reverse transcriptase activity production in HDAC4(+) ACH-2 T-lymphocytic cells but not in HDAC4(-) U1 promonocytic cells. Thus, amino acid deprivation leads to transcriptional derepression of silenced transgenes, including integrated plasmids and retroviruses, by a process involving inactivation or down-regulation of HDAC4. These findings suggest that selective targeting of HDAC4 might represent a unique strategy for modulating the expression of therapeutic viral vectors, as well as that of integrated HIV-1 proviruses in latent reservoirs without significant cytotoxicity.

  12. Amino acid starvation induces reactivation of silenced transgenes and latent HIV-1 provirus via down-regulation of histone deacetylase 4 (HDAC4).

    PubMed

    Palmisano, Ilaria; Della Chiara, Giulia; D'Ambrosio, Rosa Lucia; Huichalaf, Claudia; Brambilla, Paola; Corbetta, Silvia; Riba, Michela; Piccirillo, Rosanna; Valente, Sergio; Casari, Giorgio; Mai, Antonello; Martinelli Boneschi, Filippo; Gabellini, Davide; Poli, Guido; Schiaffino, Maria Vittoria

    2012-08-21

    The epigenetic silencing of exogenous transcriptional units integrated into the genome represents a critical problem both for long-term gene therapy efficacy and for the eradication of latent viral infections. We report here that limitation of essential amino acids, such as methionine and cysteine, causes selective up-regulation of exogenous transgene expression in mammalian cells. Prolonged amino acid deprivation led to significant and reversible increase in the expression levels of stably integrated transgenes transcribed by means of viral or human promoters in HeLa cells. This phenomenon was mediated by epigenetic chromatin modifications, because histone deacetylase (HDAC) inhibitors reproduced starvation-induced transgene up-regulation, and transcriptome analysis, ChIP, and pharmacological and RNAi approaches revealed that a specific class II HDAC, namely HDAC4, plays a critical role in maintaining the silencing of exogenous transgenes. This mechanism was also operational in cells chronically infected with HIV-1, the etiological agent of AIDS, in a latency state. Indeed, both amino acid starvation and pharmacological inhibition of HDAC4 promoted reactivation of HIV-1 transcription and reverse transcriptase activity production in HDAC4(+) ACH-2 T-lymphocytic cells but not in HDAC4(-) U1 promonocytic cells. Thus, amino acid deprivation leads to transcriptional derepression of silenced transgenes, including integrated plasmids and retroviruses, by a process involving inactivation or down-regulation of HDAC4. These findings suggest that selective targeting of HDAC4 might represent a unique strategy for modulating the expression of therapeutic viral vectors, as well as that of integrated HIV-1 proviruses in latent reservoirs without significant cytotoxicity. PMID:22826225

  13. 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

  14. Targeting epigenetic reader and eraser: Rational design, synthesis and in vitro evaluation of dimethylisoxazoles derivatives as BRD4/HDAC dual inhibitors.

    PubMed

    Zhang, Zhimin; Hou, Shaohua; Chen, Hongli; Ran, Ting; Jiang, Fei; Bian, Yuanyuan; Zhang, Dewei; Zhi, Yanle; Wang, Lu; Zhang, Li; Li, Hongmei; Zhang, Yanmin; Tang, Weifang; Lu, Tao; Chen, Yadong

    2016-06-15

    The bromodomain protein module and histone deacetylase (HDAC), which recognize and remove acetylated lysine, respectively, have emerged as important epigenetic therapeutic targets in cancer treatments. Herein we presented a novel design approach for cancer drug development by combination of bromodomain and HDAC inhibitory activity in one molecule. The designed compounds were synthesized which showed inhibitory activity against bromodomain 4 and HDAC1. The representative dual bromodomain/HDAC inhibitors, compound 11 and 12, showed potent antiproliferative activities against human leukaemia cell line K562 and MV4-11 in cellular assays. This work may lay the foundation for developing dual bromodomain/HDAC inhibitors as potential anticancer therapeutics.

  15. The levels of HDAC1 and thioredoxin1 are related to the death of mesothelioma cells by suberoylanilide hydroxamic acid.

    PubMed

    You, Bo Ra; Park, Woo Hyun

    2016-05-01

    Mesothelioma is an aggressive tumor which is mainly derived from the pleura of lung. In the present study, we evaluated the anticancer effect of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor on human mesothelioma cells in relation to the levels of HDAC1, reactive oxygen species (ROS) and thioredoxin (Trx). While 1 µM SAHA inhibited cell growth in Phi and ROB cells at 24 h, it did not affect the growth in ADA and Mill cells. Notably, the level of HDAC1 was relatively overexpressed among Phi, REN and ROB cells. SAHA induced necrosis and apoptosis, which was accompanied by the cleavages of PARP and caspase-3 in Phi cells. This agent also increased the loss of mitochondrial membrane potential (MMP, ΔΨm) in Phi cells. All the tested caspase inhibitors attenuated apoptosis in SAHA-treated Phi cells whereas HDAC1 siRNA enhanced the apoptotic cell death. SAHA increased intracellular ROS levels including O2•- in Phi cells. N-acetyl cysteine (NAC) and vitamin C (Vit.C) significantly reduced the growth inhibition and death of Phi cells caused by SAHA. This drug decreased the mRNA and protein levels of Trx1 in Phi and ROB cells. Furthermore, Trx1 siRNA increased cell death and O2•- level in SAHA-treated Phi cells. In conclusion, SAHA selectively inhibited the growth of Phi and ROB mesothelioma cells, which showed the higher basal level of HDAC1. SAHA-induced Phi cell death was related to oxidative stress and Trx1 levels. PMID:26936390

  16. 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

    2016-02-01

    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.

  17. 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. PMID:26101158

  18. Effect of HDAC Inhibitors on Corneal Keratocyte Mechanical Phenotypes in 3-D Collagen Matrices

    PubMed Central

    Koppaka, Vindhya; Lakshman, Neema

    2015-01-01

    Purpose: Histone deacetylase inhibitors (HDAC) have been shown to inhibit the TGFβ-induced myofibroblast transformation of corneal fibroblasts in 2-D culture. However, the effect of HDAC inhibitors on keratocyte spreading, contraction, and matrix remodeling in 3-D culture has not been directly assessed. The goal of this study was to investigate the effects of the HDAC inhibitors Trichostatin A (TSA) and Vorinostat (SAHA) on corneal keratocyte mechanical phenotypes in 3-D culture using defined serum-free culture conditions. Methods: Rabbit corneal keratocytes were plated within standard rat tail type I collagen matrices (2.5 mg/ml) or compressed collagen matrices (~100 mg/ml) and cultured for up to 4 days in serum-free media, PDGF BB, TGFβ1, and either 50 nM TSA, 10 μM SAHA, or vehicle (DMSO). F-actin, α-SM-actin, and collagen fibrils were imaged using confocal microscopy. Cell morphology and global matrix contraction were quantified digitally. The expression of α-SM-actin was assessed using western blotting. Results: Corneal keratocytes in 3-D matrices had a quiescent mechanical phenotype, as indicated by a dendritic morphology, a lack of stress fibers, and minimal cell-induced matrix remodeling. This phenotype was generally maintained following the addition of TSA or SAHA. TGFβ1 induced a contractile phenotype, as indicated by a loss of dendritic cell processes, the development of stress fibers, and significant matrix compaction. In contrast, cells cultured in TGFβ1 plus TSA or SAHA remained dendritic and did not form stress fibers or induce ECM compaction. Western blotting showed that the expression of α-SM actin after treatment with TGFβ1 was inhibited by TSA and SAHA. PDGF BB stimulated the elongation of keratocytes and the extension of dendritic processes within 3-D matrices without inducing stress fiber formation or collagen reorganization. This spreading response was maintained in the presence of TSA or SAHA. Conclusions: Overall, HDAC inhibitors

  19. Design, synthesis and biological evaluation of N-phenylquinazolin-4-amine hybrids as dual inhibitors of VEGFR-2 and HDAC.

    PubMed

    Peng, Fan-Wei; Xuan, Ji; Wu, Ting-Ting; Xue, Jia-Yu; Ren, Zi-Wei; Liu, Da-Ke; Wang, Xiu-Qi; Chen, Xin-Hang; Zhang, Jia-Wei; Xu, Yun-Gen; Shi, Lei

    2016-02-15

    A single agent that simultaneously inhibits multiple targets may offer greater therapeutic benefits in cancer than single-acting agents through interference with multiple pathways and potential synergistic action. In this work, a series of hybrids bearing N-phenylquinazolin-4-amine and hydroxamic acid moieties were designed and identified as dual VEGFR-2/HDAC inhibitors. Compound 6fd exhibited the most potent inhibitory activity against HDAC with IC50 of 2.2 nM and strong inhibitory effect against VEGFR-2 with IC50 of 74 nM. It also showed the most potent inhibitory activity against a human breast cancer cell line MCF-7 with IC50 of 0.85 μM. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the active binding sites of VEGFR-2 and HDLP ((Histone Deacetylase-Like Protein), which demonstrates that compound 6fd is a potential agent for cancer therapy deserving further researching. PMID:26741358

  20. 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

  1. MuLV IN Mutants Responsive to HDAC Inhibitors Enhance Transcription from Unintegrated Retroviral DNA

    PubMed Central

    Schneider, William M.; Wu, Dai-tze; Amin, Vaibhav; Aiyer, Sriram; Roth, Monica J.

    2012-01-01

    For Moloney murine leukemia virus (M-MuLV), sustained viral infections require expression from an integrated provirus. For many applications, non-integrating retroviral vectors have been utilized to avoid the unwanted effects of integration, however, the level of expression from unintegrated DNA is significantly less than that of integrated provirus. We find that unintegrated DNA expression can be increased in the presence of HDAC inhibitors, such as TSA, when applied in combination with integrase (IN) mutations. These mutants include an active site mutation as well as catalytically active INs bearing mutations of K376 in the MuLV C-terminal domain of IN. MuLV IN K376 is homologous to K266 in HIV-1 IN, a known substrate for acetylation. The MuLV IN protein is acetylated by p300 in vitro, however, the effect of HDAC inhibitors on gene expression from unintegrated DNA is not dependent on the acetylation state of MuLV IN K376. PMID:22365328

  2. The emerging role of histone deacetylase (HDAC) inhibitors in urological cancers.

    PubMed

    Sharma, Naomi L; Groselj, Blaz; Hamdy, Freddie C; Kiltie, Anne E

    2013-04-01

    WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: A growing body of evidence supports the anti-cancer effect of histone deacetylase inhibitors (HDACi) in vitro, via multiple pathways, and many Phase I clinical trials have shown them to be well-tolerated in a range of malignancies. Combined therapies, including with radiation, present an exciting area of current and planned study. This review summarises the evidence to date, including pre-clinical data and clinical trials, of the anti-cancer effect of HDACi in urological cancers. It provides an overview of epigenetics and the mechanisms of action of HDACi. It suggests areas of future development, including the current challenges for the successful introduction of HDACi into clinical therapy. Epigenetic modifications are known to play a critical role in the development and progression of many cancers. The opposing actions of histone deacetylases (HDACs) and histone acetyltransferases (HATs) modify chromatin and lead to epigenetic gene regulation, in addition to wider effects on non-histone proteins. There is growing interest in the clinical application of HDAC inhibitors (HDACi) in cancer. HDACi have been shown to inhibit cancer cell growth both in vitro and in vivo and recent clinical trials have shown encouraging results in various urological cancers. In this review, we discuss the existing evidence and potential role for HDACi in urological malignancies, including in combined therapies.

  3. HDAC inhibitor reduces cytokine storm and facilitates induction of chimerism that reverses lupus in anti-CD3 conditioning regimen.

    PubMed

    Li, Nainong; Zhao, Dongchang; Kirschbaum, Mark; Zhang, Chunyan; Lin, Chia-Lei; Todorov, Ivan; Kandeel, Fouad; Forman, Stephen; Zeng, Defu

    2008-03-25

    In allogeneic hematopoietic cell transplantation (HCT), donor T cell-mediated graft versus host leukemia (GVL) and graft versus autoimmune (GVA) activity play critical roles in treatment of hematological malignancies and refractory autoimmune diseases. However, graft versus host disease (GVHD), which sometimes can be fatal, remains a major obstacle in classical HCT, where recipients are conditioned with total body irradiation or high-dose chemotherapy. We previously reported that anti-CD3 conditioning allows donor CD8(+) T cells to facilitate engraftment and mediate GVL without causing GVHD. However, the clinical application of this radiation-free and GVHD preventative conditioning regimen is hindered by the cytokine storm syndrome triggered by anti-CD3 and the high-dose donor bone marrow (BM) cells required for induction of chimerism. Histone deacetylase (HDAC) inhibitors such as suberoylanilide hydroxamic acid (SAHA) are known to induce apoptosis of cancer cells and reduce production of proinflammatory cytokines by nonmalignant cells. Here, we report that SAHA inhibits the proliferative and cytotoxic activity of anti-CD3-activated T cells. Administration of low-dose SAHA reduces cytokine production and ameliorates the cytokine storm syndrome triggered by anti-CD3. Conditioning with anti-CD3 and SAHA allows induction of chimerism with lower doses of donor BM cells in old nonautoimmune and autoimmune lupus mice. In addition, conditioning with anti-CD3 and SAHA allows donor CD8(+) T cell-mediated GVA activity to reverse lupus glomerulonephritis without causing GVHD. These results indicate that conditioning with anti-CD3 and HDAC inhibitors represent a radiation-free and GVHD-preventative regimen with clinical application potential.

  4. Selective inhibition of esophageal cancer cells by combination of HDAC inhibitors and Azacytidine.

    PubMed

    Ahrens, Theresa D; Timme, Sylvia; Hoeppner, Jens; Ostendorp, Jenny; Hembach, Sina; Follo, Marie; Hopt, Ulrich T; Werner, Martin; Busch, Hauke; Boerries, Melanie; Lassmann, Silke

    2015-01-01

    Esophageal cancers are highly aggressive tumors with poor prognosis despite some recent advances in surgical and radiochemotherapy treatment options. This study addressed the feasibility of drugs targeting epigenetic modifiers in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells. We tested inhibition of histone deacetylases (HDACs) by SAHA, MS-275, and FK228, inhibition of DNA methyltransferases by Azacytidine (AZA) and Decitabine (DAC), and the effect of combination treatment using both types of drugs. The drug targets, HDAC1/2/3 and DNMT1, were expressed in normal esophageal epithelium and tumor cells of ESCC or EAC tissue specimens, as well as in non-neoplastic esophageal epithelial (Het-1A), ESCC (OE21, Kyse-270, Kyse-410), and EAC (OE33, SK-GT-4) cell lines. In vitro, HDAC activity, histone acetylation, and p21 expression were similarly affected in non-neoplastic, ESCC, and EAC cell lines post inhibitor treatment. Combined MS-275/AZA treatment, however, selectively targeted esophageal cancer cell lines by inducing DNA damage, cell viability loss, and apoptosis, and by decreasing cell migration. Non-neoplastic Het-1A cells were protected against HDACi (MS-275)/AZA treatment. RNA transcriptome analyses post MS-275 and/or AZA treatment identified novel regulated candidate genes (up: BCL6, Hes2; down: FAIM, MLKL), which were specifically associated with the treatment responses of esophageal cancer cells. In summary, combined HDACi/AZA treatment is efficient and selective for the targeting of esophageal cancer cells, despite similar target expression of normal and esophageal cancer epithelium, in vitro and in human esophageal carcinomas. The precise mechanisms of action of treatment responses involve novel candidate genes regulated by HDACi/AZA in esophageal cancer cells. Together, targeting of epigenetic modifiers in esophageal cancers may represent a potential future therapeutic approach.

  5. Selective inhibition of esophageal cancer cells by combination of HDAC inhibitors and Azacytidine

    PubMed Central

    Ahrens, Theresa D; Timme, Sylvia; Hoeppner, Jens; Ostendorp, Jenny; Hembach, Sina; Follo, Marie; Hopt, Ulrich T; Werner, Martin; Busch, Hauke; Boerries, Melanie; Lassmann, Silke

    2015-01-01

    Esophageal cancers are highly aggressive tumors with poor prognosis despite some recent advances in surgical and radiochemotherapy treatment options. This study addressed the feasibility of drugs targeting epigenetic modifiers in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells. We tested inhibition of histone deacetylases (HDACs) by SAHA, MS-275, and FK228, inhibition of DNA methyltransferases by Azacytidine (AZA) and Decitabine (DAC), and the effect of combination treatment using both types of drugs. The drug targets, HDAC1/2/3 and DNMT1, were expressed in normal esophageal epithelium and tumor cells of ESCC or EAC tissue specimens, as well as in non-neoplastic esophageal epithelial (Het-1A), ESCC (OE21, Kyse-270, Kyse-410), and EAC (OE33, SK-GT-4) cell lines. In vitro, HDAC activity, histone acetylation, and p21 expression were similarly affected in non-neoplastic, ESCC, and EAC cell lines post inhibitor treatment. Combined MS-275/AZA treatment, however, selectively targeted esophageal cancer cell lines by inducing DNA damage, cell viability loss, and apoptosis, and by decreasing cell migration. Non-neoplastic Het-1A cells were protected against HDACi (MS-275)/AZA treatment. RNA transcriptome analyses post MS-275 and/or AZA treatment identified novel regulated candidate genes (up: BCL6, Hes2; down: FAIM, MLKL), which were specifically associated with the treatment responses of esophageal cancer cells. In summary, combined HDACi/AZA treatment is efficient and selective for the targeting of esophageal cancer cells, despite similar target expression of normal and esophageal cancer epithelium, in vitro and in human esophageal carcinomas. The precise mechanisms of action of treatment responses involve novel candidate genes regulated by HDACi/AZA in esophageal cancer cells. Together, targeting of epigenetic modifiers in esophageal cancers may represent a potential future therapeutic approach. PMID:25923331

  6. 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. PMID:26937828

  7. Induction of autophagy by valproic acid enhanced lymphoma cell chemosensitivity through HDAC-independent and IP3-mediated PRKAA activation.

    PubMed

    Ji, Meng-Meng; Wang, Li; Zhan, Qin; Xue, Wen; Zhao, Yan; Zhao, Xia; Xu, Peng-Peng; Shen, Yang; Liu, Han; Janin, Anne; Cheng, Shu; Zhao, Wei-Li

    2015-01-01

    Autophagy is closely related to tumor cell sensitivity to anticancer drugs. The HDAC (histone deacetylase) inhibitor valproic acid (VPA) interacted synergistically with chemotherapeutic agents to trigger lymphoma cell autophagy, which resulted from activation of AMPK (AMP-activated protein kinase) and inhibition of downstream MTOR (mechanistic target of rapamycin [serine/threonine kinase]) signaling. In an HDAC-independent manner, VPA potentiated the effect of doxorubicin on lymphoma cell autophagy via reduction of cellular inositol 1,4,5 trisphosphate (IP3), blockade of calcium into mitochondria and modulation of PRKAA1/2-MTOR cascade. In murine xenograft models established with subcutaneous injection of lymphoma cells, dual treatment of VPA and doxorubicin initiated IP3-mediated calcium depletion and PRKAA1/2 activation, induced in situ autophagy and efficiently retarded tumor growth. Aberrant genes involving mitochondrial calcium transfer were frequently observed in primary tumors of lymphoma patients. Collectively, these findings suggested an HDAC-independent chemosensitizing activity of VPA and provided an insight into the clinical application of targeting autophagy in the treatment of lymphoma.

  8. 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

  9. 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.

  10. 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.

  11. 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. PMID:26611919

  12. Design, synthesis and preliminary biological evaluation of indoline-2,3-dione derivatives as novel HDAC inhibitors.

    PubMed

    Jin, Kang; Li, Shanshan; Li, Xiaoguang; Zhang, Jian; Xu, Wenfang; Li, Xuechen

    2015-08-01

    Histone deacetylases (HDACs) are zinc-dependent or NAD(+) dependent enzymes and play a critical role in the process of tumor development. Herein a series of indoline-2,3-dione derivatives have been designed and synthesized as potential HDACs inhibitors. The preliminary biological evaluation showed that most compounds synthesized have exhibited moderate Hela cell nuclear extract inhibitory activities, among which compound 25a (IC50=10.13 nM) has shown the best efficacy. The anti-proliferative activities of some of these compounds were also discussed. PMID:26100440

  13. 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

    2016-05-01

    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

  14. mTORC1/C2 and pan-HDAC inhibitors synergistically impair breast cancer growth by convergent AKT and polysome inhibiting mechanisms.

    PubMed

    Wilson-Edell, Kathleen A; Yevtushenko, Mariya A; Rothschild, Daniel E; Rogers, Aric N; Benz, Christopher C

    2014-04-01

    Resistance of breast cancers to targeted hormone receptor (HR) or human epidermal growth factor receptor 2 (HER2) inhibitors often occurs through dysregulation of the phosphoinositide 3-kinase, protein kinase B/AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Presently, no targeted therapies exist for breast cancers lacking HR and HER2 overexpression, many of which also exhibit PI3K/AKT/mTOR hyper-activation. Resistance of breast cancers to current therapeutics also results, in part, from aberrant epigenetic modifications including protein acetylation regulated by histone deacetylases (HDACs). We show that the investigational drug MLN0128, which inhibits both complexes of mTOR (mTORC1 and mTORC2), and the hydroxamic acid pan-HDAC inhibitor TSA synergistically inhibit the viability of a phenotypically diverse panel of five breast cancer cell lines (HR-/+, HER2-/+). The combination of MLN0128 and TSA induces apoptosis in most breast cancer cell lines tested, but not in the non-malignant MCF-10A mammary epithelial cells. In parallel, the MLN0128/TSA combination reduces phosphorylation of AKT at S473 more than single agents alone and more so in the 5 malignant breast cancer cell lines than in the non-malignant mammary epithelial cells. Examining polysome profiles from one of the most sensitive breast cancer cell lines (SKBR3), we demonstrate that this MLN0128/TSA treatment combination synergistically impairs polysome assembly in conjunction with enhanced inhibition of 4eBP1 phosphorylation at S65. Taken together, these data indicate that the synergistic growth inhibiting consequence of combining a mTORC1/C2 inhibitor like MLN0128 with a pan-HDAC inhibitor like TSA results from their mechanistic convergence onto the PI3K/AKT/mTOR pathway, profoundly inhibiting both AKT S473 and 4eBP1 S65 phosphorylation, reducing polysome formation and cancer cell viability.

  15. 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.

  16. 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

  17. Histone deacetylases inhibitor sodium butyrate inhibits JAK2/STAT signaling through upregulation of SOCS1 and SOCS3 mediated by HDAC8 inhibition in myeloproliferative neoplasms.

    PubMed

    Gao, Shen-meng; Chen, Chi-qi; Wang, Lu-yao; Hong, Li-li; Wu, Jian-bo; Dong, Pei-hong; Yu, Fu-jun

    2013-03-01

    Constitutive activation of Janus kinase 2/signal transducers and activators of transcription (JAK2/STAT) signaling has an important role in the oncogenesis of myeloproliferative neoplasms (MPNs) and leukemia. Histone deacetylases (HDACs) inhibitors have been reported to possess anticancer activity through different mechanisms. However, whether HDACs inhibitors suppress JAK2/STAT signaling in MPNs is still unknown. In this study, we show that the HDAC inhibitor sodium butyrate (SB) inhibited JAK2/STAT signaling and increased the expression of suppressors of cytokine signaling 1 (SOCS1) and SOCS3, both of which are the potent feedback inhibitors of JAK2/STAT signaling. SB upregulated the expression of SOCS1 and SOCS3 by triggering the promoter-associated histone acetylation of SOCS1 and SOCS3 in K562 and HEL cell lines. Importantly, we found that upon knockdown of each class I HDACs, only knockdown of HDAC8 resulted in the increased expression of SOCS1 and SOCS3. Moreover, overexpression of SOCS1 and SOCS3 significantly inhibited cell growth and suppressed JAK2/STAT signaling in K562 and HEL cells. Furthermore, SB increased the transcript levels of SOCS1 and SOCS3 and inhibited the clonogenic activity of hematopoietic progenitors from patients with MPNs. Taken together, these data establish a new anticancer mechanism that SB inhibits JAK2/STAT signaling through HDAC8-mediated upregulation of SOCS1 and SOCS3. Thus, HDACs inhibitors may have therapeutic potential for the treatment of MPNs.

  18. Transcript, methylation and molecular docking analyses of the effects of HDAC inhibitors, SAHA and Dacinostat, on SMN2 expression in fibroblasts of SMA patients.

    PubMed

    Mohseni, Jafar; Al-Najjar, Belal O; Wahab, Habibah A; Zabidi-Hussin, Z A M H; Sasongko, Teguh Haryo

    2016-09-01

    Several histone deacetylase inhibitors (HDACis) are known to increase Survival Motor Neuron 2 (SMN2) expression for the therapy of spinal muscular atrophy (SMA). We aimed to compare the effects of suberoylanilide hydroxamic acid (SAHA) and Dacinostat, a novel HDACi, on SMN2 expression and to elucidate their acetylation effects on the methylation of the SMN2. Cell-based assays using type I and type II SMA fibroblasts examined changes in transcript expressions, methylation levels and protein expressions. In silico methods analyzed the intermolecular interactions between each compound and HDAC2/HDAC7. SMN2 mRNA transcript levels and SMN protein levels showed notable increases in both cell types, except for Dacinostat exposure on type II cells. However, combined compound exposures showed less pronounced increase in SMN2 transcript and SMN protein level. Acetylation effects of SAHA and Dacinostat promoted demethylation of the SMN2 promoter. The in silico analyses revealed identical binding sites for both compounds in HDACs, which could explain the limited effects of the combined exposure. With the exception on the effect of Dacinostat in Type II cells, we have shown that SAHA and Dacinostat increased SMN2 transcript and protein levels and promoted demethylation of the SMN2 gene.

  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. PMID:27548648

  20. Boronic acid-based enzyme inhibitors: a review of recent progress.

    PubMed

    Fu, H; Fang, H; Sun, Jie; Wang, H; Liu, A; Sun, J; Wu, Z

    2014-01-01

    Since Bortezomib was approved by US FDA as the first drug to treat multiple myeloma, various boronic acid compounds have been developed as enzyme inhibitors. This paper reviewed the progress of boronic acid-based inhibitors against enzymes including proteasome, serine protease, HDACs and other enzymes in the past decade.

  1. Biochemical, biological and structural properties of romidepsin (FK228) and its analogs as novel HDAC/PI3K dual inhibitors.

    PubMed

    Saijo, Ken; Imamura, Jin; Narita, Koichi; Oda, Akifumi; Shimodaira, Hideki; Katoh, Tadashi; Ishioka, Chikashi

    2015-02-01

    Romidepsin (FK228, depsipeptide) is a potent histone deacetylase (HDAC) inhibitor that has FDA approval for the treatment of cutaneous and peripheral T-cell lymphomas. We have previously reported that FK228 and its analogs have an additional activity as phosphatidylinositol 3-kinase (PI3K) inhibitors, and are defined as HDAC/PI3K dual inhibitors. Because a combination of an HDAC inhibitor and a PI3K inhibitor induces apoptosis in human cancer cells in a synergistic manner, development of an HDAC/PI3K dual inhibitor will provide an attractive novel drug for cancer therapy. Using structure-based optimization of the analogs, FK-A11 was identified as the most potent analog. FK-A11 inhibited phosphorylation of AKT and accelerated histone acetylation at lower concentrations, resulting in stronger cytotoxic effects than FK228 and the other analogs in human cancer cells. In this study, we have characterized the biochemical, biological and structural properties of FK228 analogs as PI3K inhibitors. First, FK-A11 is an ATP competitive PI3K inhibitor. Second, FK-A11 is a pan-p110 isoform inhibitor. Third, FK-A11 selectively inhibits PI3K among 22 common cellular kinases. Fourth, conformational changes of FK228 analogs by reduction of an internal disulfide bond have no effect on PI3K inhibitory activity, unlike HDAC inhibitory activity. Finally, molecular modeling of PI3K-FK228 analogs and analyses of the binding affinities identified the structure that defines potency for PI3K inhibitory activity. These results prove our concept that a series of FK228 analogs are HDAC/PI3K dual inhibitors. These findings should help in the development of FK228 analogs as novel HDAC/PI3K dual inhibitors.

  2. Synthesis and biological evaluation of ortho-aryl N-hydroxycinnamides as potent histone deacetylase (HDAC) 8 isoform-selective inhibitors.

    PubMed

    Huang, Wei-Jan; Wang, Yi-Ching; Chao, Shi-Wei; Yang, Chen-Yui; Chen, Liang-Chieh; Lin, Mei-Hsiang; Hou, Wen-Chi; Chen, Mei-Yu; Lee, Tai-Lin; Yang, Ping; Chang, Chung-I

    2012-10-01

    Histone deacetylases (HDACs) are a family of enzymes that play a crucial role in biological process and diseases. In contrast to other isozymes, HDAC8 is uniquely incapable of histone acetylation. In order to delineate its physiological function, we developed HDAC8-selective inhibitors using knowledge-based design combined with structural modeling techniques. Enzyme inhibitory analysis demonstrated that some of the resulting compounds (22 b, 22 d, 22 f, and 22 g) exhibited anti-HDAC8 activity superior to PCI34051, a known HDAC8-specific inhibitor, with IC(50) values in the range of 5-50 nM. Among them, compound 22 d showed antiproliferative effects toward several human lung cancer cell lines (A549, H1299, and CL1-5); it exhibited cytotoxicity against human lung CL1-5 cells similar to that of SAHA yet without significant cytotoxicity for normal IMR-90 cells. Expression profiling of HDAC isoforms in three cancer cell lines indicated that the HDAC8 level in CL1-5 is higher than that in H1299 and CL1-1 cells, a result consistent with the differential cytotoxicity of compound 22 d. These results suggest the effectiveness of our design concept, which may lead to a tool compound for studying the specific role of HDAC8 in cellular biological processes.

  3. The histone deacetylase HDAC3 is essential for Purkinje cell function, potentially complicating the use of HDAC inhibitors in SCA1.

    PubMed

    Venkatraman, Anand; Hu, Yuan-Shih; Didonna, Alessandro; Cvetanovic, Marija; Krbanjevic, Aleksandar; Bilesimo, Patrice; Opal, Puneet

    2014-07-15

    Spinocerebellar ataxia type 1 (SCA1) is an incurable neurodegenerative disease caused by a pathogenic glutamine repeat expansion in the protein ataxin-1 (ATXN1). One likely mechanism mediating pathogenesis is excessive transcriptional repression induced by the expanded ATXN-1. Because ATXN1 binds HDAC3, a Class I histone deacetylase (HDAC) that we have found to be required for ATXN1-induced transcriptional repression, we tested whether genetically depleting HDAC3 improves the phenotype of the SCA1 knock-in mouse (SCA1(154Q/2Q)), the most physiologically relevant model of SCA1. Given that HDAC3 null mice are embryonic lethal, we used for our analyses a combination of HDAC3 haploinsufficient and Purkinje cell (PC)-specific HDAC3 null mice. Although deleting a single allele of HDAC3 in the context of SCA1 was insufficient to improve cerebellar and cognitive deficits of the disease, a complete loss of PC HDAC3 was highly deleterious both behaviorally, with mice showing early onset ataxia, and pathologically, with progressive histologic evidence of degeneration. Inhibition of HDAC3 may yet have a role in SCA1 therapy, but our study provides cautionary evidence that this approach could produce untoward effects. Indeed, the neurotoxic consequences of HDAC3 depletion could prove relevant, wherever pharmacologic inhibition of HDAC3 is being contemplated, in disorders ranging from cancer to neurodegeneration.

  4. 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.

  5. 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.

  6. HDAC inhibitor misprocesses bantam oncomiRNA, but stimulates hid induced apoptotic pathway

    PubMed Central

    Bhadra, Utpal; Mondal, Tanmoy; Bag, Indira; Mukhopadhyay, Debasmita; Das, Paromita; Parida, Bibhuti B.; Mainkar, Prathama S.; Reddy, Chada Raji; Bhadra, Manika Pal

    2015-01-01

    Apoptosis or programmed cell death is critical for embryogenesis and tissue homeostasis. Uncontrolled apoptosis leads to different human disorders including immunodeficiency, autoimmune disorder and cancer. Several small molecules that control apoptosis have been identified. Here, we have shown the functional role of triazole derivative (DCPTN-PT) that acts as a potent HDAC inhibitor and mis-express proto onco microRNA (miRNA) bantam. To further understanding the mechanism of action of the molecule in apoptotic pathway, a series of experiments were also performed in Drosophila, a well known model organism in which the nature of human apoptosis is very analogous. DCPTN-PT mis processes bantam microRNA and alters its down regulatory target hid function and cleavage of Caspase-3 which in turn influence components of the mitochondrial apoptotic pathway in Drosophila. However regulatory microRNAs in other pro-apoptotic genes are not altered. Simultaneously, treatment of same molecule also affects the mitochondrial regulatory pathway in human tumour cell lines suggesting its conservative nature between fly and human. It is reasonable to propose that triazole derivative (DCPTN-PT) controls bantam oncomiRNA and increases hid induced apoptosis and is also able to influence mitochondrial apoptotic pathway. PMID:26442596

  7. HDAC Inhibitors Increase NRF2-Signaling in Tumour Cells and Blunt the Efficacy of Co-Adminstered Cytotoxic Agents

    PubMed Central

    McMahon, Michael; Campbell, Kathryn H.; MacLeod, A. Kenneth; McLaughlin, Lesley A.; Henderson, Colin J.; Wolf, C. Roland

    2014-01-01

    The NRF2 signalling cascade provides a primary response against electrophilic chemicals and oxidative stress. The activation of NRF2-signaling is anticipated to have adverse clinical consequences; NRF2 is activated in a number of cancers and, additionally, its pharmacological activation by one compound can reduce the toxicity or efficiency of a second agent administered concomitantly. In this work, we have analysed systematically the ability of 152 research, pre-clinical or clinically used drugs to induce an NRF2 response using the MCF7-AREc32 NRF2 reporter. Ten percent of the tested drugs induced an NRF2 response. The NRF2 activators were not restricted to classical cytotoxic alkylating agents but also included a number of emerging anticancer drugs, including an IGF1-R inhibitor (NVP-AEW541), a PIM-1 kinase inhibitor (Pim1 inhibitor 2), a PLK1 inhibitor (BI 2536) and most strikingly seven of nine tested HDAC inhibitors. These findings were further confirmed by demonstrating NRF2-dependent induction of endogenous AKR genes, biomarkers of NRF2 activity. The ability of HDAC inhibitors to stimulate NRF2-signalling did not diminish their own potency as antitumour agents. However, when used to pre-treat cells, they did reduce the efficacy of acrolein. Taken together, our data suggest that the ability of drugs to stimulate NRF2 activity is common and should be investigated as part of the drug-development process. PMID:25427220

  8. HDAC inhibitors increase NRF2-signaling in tumour cells and blunt the efficacy of co-adminstered cytotoxic agents.

    PubMed

    McMahon, Michael; Campbell, Kathryn H; MacLeod, A Kenneth; McLaughlin, Lesley A; Henderson, Colin J; Wolf, C Roland

    2014-01-01

    The NRF2 signalling cascade provides a primary response against electrophilic chemicals and oxidative stress. The activation of NRF2-signaling is anticipated to have adverse clinical consequences; NRF2 is activated in a number of cancers and, additionally, its pharmacological activation by one compound can reduce the toxicity or efficiency of a second agent administered concomitantly. In this work, we have analysed systematically the ability of 152 research, pre-clinical or clinically used drugs to induce an NRF2 response using the MCF7-AREc32 NRF2 reporter. Ten percent of the tested drugs induced an NRF2 response. The NRF2 activators were not restricted to classical cytotoxic alkylating agents but also included a number of emerging anticancer drugs, including an IGF1-R inhibitor (NVP-AEW541), a PIM-1 kinase inhibitor (Pim1 inhibitor 2), a PLK1 inhibitor (BI 2536) and most strikingly seven of nine tested HDAC inhibitors. These findings were further confirmed by demonstrating NRF2-dependent induction of endogenous AKR genes, biomarkers of NRF2 activity. The ability of HDAC inhibitors to stimulate NRF2-signalling did not diminish their own potency as antitumour agents. However, when used to pre-treat cells, they did reduce the efficacy of acrolein. Taken together, our data suggest that the ability of drugs to stimulate NRF2 activity is common and should be investigated as part of the drug-development process.

  9. 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 Central

    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. PMID:27249803

  10. CD1d induction in solid tumor cells by histone deacetylase inhibitors through inhibition of HDAC1/2 and activation of Sp1.

    PubMed

    Yang, Pei-Ming; Lin, Pei-Jie; Chen, Ching-Chow

    2012-04-01

    CD1d is a MHC class-like molecule that presents glycolipids to natural killer T (NKT) cells, then regulates innate and adaptive immunity. The regulation of CD1d gene expression in solid tumors is still largely unknown. Gene expression can be epigenetically regulated by DNA methylation and histone acetylation. We found that histone deacetylase inhibitors, trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), induced CD1d gene expression in human (A549 and NCI-H292) and mouse (TC-1 and B16/F0) cancer cells. Simultaneous knockdown of HDAC1 and 2 induced CD1d gene expression. Sp1 inhibitor mitramycin A (MTM) blocked TSA- and SAHA-induced CD1d mRNA expression and Sp1 luciferase activity. Co-transfection of GAL4-Sp1 and Fc-luciferase reporters demonstrated that TSA and SAHA induced Sp1 luciferase reporter activity by enhancing Sp1 transactivation activity. The binding of Sp1 to CD1d promoter and histone H3 acetylation on Sp1 sites were increased by TSA and SAHA. These results indicate that TSA and SAHA could up-regulate CD1d expression in tumor cells through inhibition of HDAC1/2 and activation of Sp1. PMID:22419072

  11. Passport control for foreign integrated DNAs: An unexpected checkpoint by class II HDAC4 revealed by amino acid starvation.

    PubMed

    Palmisano, Ilaria; Della Chiara, Giulia; Schiaffino, Maria Vittoria; Poli, Guido

    2012-09-01

    The endless battle between mammalian host cells and microbes has evolved mechanisms to shut down the expression of exogenous transcriptional units integrated into the genome with the goal of limiting their spreading. Recently, we observed that deprivation of essential amino acids leads to a selective, reversible upregulation of expression of exogenous transgenes, either carried by integrated plasmids or retroviral vectors, but not of their endogenous counterparts. This effect was dependent on epigenetic modifications and was mediated by the downregulation of the class II histone deacetylase-4 (HDAC4). Indeed, HDAC4 expression inversely correlated with that of the transgene and its inhibition or downregulation enhanced transgene expression. Could this be true also for "naturally" integrated proviruses? We investigated this question in the case of HIV-1, the etiological agent of AIDS and we observed that both amino acid starvation and HDAC4 inhibition triggered HIV-1 reactivation in chronically infected ACH-2 T lymphocytic cells (HDAC4(+)), but not in similarly infected U1 promonocytic cells (HDAC4-negative). Thus, an HDAC4-dependent pathway may contribute to unleash virus expression by latently infected cells, which represent nowadays a major obstacle to HIV eradication. We discuss here the implications and open questions of these novel findings, as well as their serendipitous prelude. PMID:23550098

  12. Synthesis and Biological Evaluation of 1-(2-Aminophenyl)-3-arylurea Derivatives as Potential EphA2 and HDAC Dual Inhibitors.

    PubMed

    Zhu, Yong; Ran, Ting; Chen, Xin; Niu, Jiaqi; Zhao, Shuang; Lu, Tao; Tang, Weifang

    2016-01-01

    A series of 1-(2-aminophenyl)-3-arylurea novel derivatives were synthesized and evaluated against Ephrin type-A receptor 2 (EphA2) and histone deacetylases (HDACs) kinase. Most of the compounds exhibited inhibitory activity against EphA2 and HDAC. The antiproliferative activities were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) (thiazolyl blue, tetrazolium blue) against the human cancer cell lines HCT116, K562 and MCF7. Compounds 5a and b showed the most potent inhibitory activity against EphA2 and HDAC. However, compound 5b exhibited higher potency against HCT116 (IC50=5.29 µM) and MCF7 (IC50=7.42 µM). 1-(2-Aminophenyl)-3-arylurea analogues may serve as new EphA2-HDAC dual inhibitors. PMID:27477652

  13. Dynamic structure-based pharmacophore model development: a new and effective addition in the histone deacetylase 8 (HDAC8) inhibitor discovery.

    PubMed

    Thangapandian, Sundarapandian; John, Shalini; Lee, Yuno; Kim, Songmi; Lee, Keun Woo

    2011-01-01

    Histone deacetylase 8 (HDAC8) is an enzyme involved in deacetylating the amino groups of terminal lysine residues, thereby repressing the transcription of various genes including tumor suppressor gene. The over expression of HDAC8 was observed in many cancers and thus inhibition of this enzyme has emerged as an efficient cancer therapeutic strategy. In an effort to facilitate the future discovery of HDAC8 inhibitors, we developed two pharmacophore models containing six and five pharmacophoric features, respectively, using the representative structures from two molecular dynamic (MD) simulations performed in Gromacs 4.0.5 package. Various analyses of trajectories obtained from MD simulations have displayed the changes upon inhibitor binding. Thus utilization of the dynamically-responded protein structures in pharmacophore development has the added advantage of considering the conformational flexibility of protein. The MD trajectories were clustered based on single-linkage method and representative structures were taken to be used in the pharmacophore model development. Active site complimenting structure-based pharmacophore models were developed using Discovery Studio 2.5 program and validated using a dataset of known HDAC8 inhibitors. Virtual screening of chemical database coupled with drug-like filter has identified drug-like hit compounds that match the pharmacophore models. Molecular docking of these hits reduced the false positives and identified two potential compounds to be used in future HDAC8 inhibitor design. PMID:22272142

  14. HDAC1 and HDAC2 restrain the intestinal inflammatory response by regulating intestinal epithelial cell differentiation.

    PubMed

    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

  15. 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

  16. 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

  17. Molecular and cellular effects of a novel hydroxamate-based HDAC inhibitor - belinostat - in glioblastoma cell lines: a preliminary report.

    PubMed

    Kusaczuk, Magdalena; Krętowski, Rafał; Stypułkowska, Anna; Cechowska-Pasko, Marzanna

    2016-10-01

    Histone deacetylase (HDAC) inhibitors are now intensively investigated as potential cytostatic agents in many malignancies. Here, we provide novel information concerning the influence of belinostat (Bel), a hydroxamate-based pan-HDAC inhibitor, on glioblastoma LN-229 and LN-18 cells. We found that LN-229 cells stimulated with 2 μmol/L of Bel for 48 h resulted in 70 % apoptosis, while equivalent treatment of LN-18 cells resulted in only 28 % apoptosis. In LN-229 cells this effect was followed by up-regulation of pro-apoptotic genes including Puma, Bim, Chop and p21. In treated LN-18 cells only p21 was markedly overexpressed. Simultaneously, LN-229 cells treated with 2 μmol/L of Bel for 48 h exhibited down-regulation of molecular chaperones GRP78 and GRP94 at the protein level. In contrast, in LN-18 cells Western blot analysis did not show any marked changes in GRP78 nor GRP94 expression. Despite noticeable overexpression of p21, there were no signs of evident G1 nor G2/M cell cycle arrest, however, the reduction in number of the S phase cells was observed in both cell lines. These results collectively suggest that Bel can be considered as potential anti-glioblastoma agent. To our knowledge this is the first report presenting the effects of belinostat treatment in glioblastoma cell lines. PMID:27468826

  18. The combination of HDAC and aminopeptidase inhibitors is highly synergistic in myeloma and leads to disruption of the NFκB signalling pathway.

    PubMed

    Smith, Emma M; Zhang, Lei; Walker, Brian A; Davenport, Emma L; Aronson, Lauren I; Krige, David; Hooftman, Leon; Drummond, Alan H; Morgan, Gareth J; Davies, Faith E

    2015-07-10

    There is a growing body of evidence supporting the use of epigenetic therapies in the treatment of multiple myeloma. We show the novel HDAC inhibitor CHR-3996 induces apoptosis in myeloma cells at concentrations in the nanomolar range and with apoptosis mediated by p53 and caspase pathways. In addition, HDAC inhibitors are highly synergistic, both in vitro and in vivo, with the aminopeptidase inhibitor tosedostat (CHR-2797). We demonstrate that the basis for this synergy is a consequence of changes in the levels of NFκB regulators BIRC3/cIAP2, A20, CYLD, and IκB, which were markedly affected by the combination. When co-administered the HDAC and aminopeptidase inhibitors caused rapid nuclear translocation of NFκB family members p65 and p52, following activation of both canonical and non-canonical NFκB signalling pathways. The subsequent up-regulation of inhibitors of NFκB activation (most significantly BIRC3/cIAP2) turned off the cytoprotective effects of the NFκB signalling response in a negative feedback loop. These results provide a rationale for combining HDAC and aminopeptidase inhibitors clinically for the treatment of myeloma patients and support the disruption of the NFκB signalling pathway as a therapeutic strategy.

  19. HDAC8 and STAT3 repress BMF gene activity in colon cancer cells.

    PubMed

    Kang, Y; Nian, H; Rajendran, P; Kim, E; Dashwood, W M; Pinto, J T; Boardman, L A; Thibodeau, S N; Limburg, P J; Löhr, C V; Bisson, W H; Williams, D E; Ho, E; Dashwood, R H

    2014-01-01

    Histone deacetylase (HDAC) inhibitors are undergoing clinical trials as anticancer agents, but some exhibit resistance mechanisms linked to anti-apoptotic Bcl-2 functions, such as BH3-only protein silencing. HDAC inhibitors that reactivate BH3-only family members might offer an improved therapeutic approach. We show here that a novel seleno-α-keto acid triggers global histone acetylation in human colon cancer cells and activates apoptosis in a p21-independent manner. Profiling of multiple survival factors identified a critical role for the BH3-only member Bcl-2-modifying factor (Bmf). On the corresponding BMF gene promoter, loss of HDAC8 was associated with signal transducer and activator of transcription 3 (STAT3)/specificity protein 3 (Sp3) transcription factor exchange and recruitment of p300. Treatment with a p300 inhibitor or transient overexpression of exogenous HDAC8 interfered with BMF induction, whereas RNAi-mediated silencing of STAT3 activated the target gene. This is the first report to identify a direct target gene of HDAC8 repression, namely, BMF. Interestingly, the repressive role of HDAC8 could be uncoupled from HDAC1 to trigger Bmf-mediated apoptosis. These findings have implications for the development of HDAC8-selective inhibitors as therapeutic agents, beyond the reported involvement of HDAC8 in childhood malignancy. PMID:25321483

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

    PubMed

    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

  1. 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

  2. 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

  3. 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

  4. Prolonged treatment with pimelic o-aminobenzamide HDAC inhibitors ameliorates the disease phenotype of a Friedreich ataxia mouse model

    PubMed Central

    Sandi, Chiranjeevi; Pinto, Ricardo Mouro; Al-Mahdawi, Sahar; Ezzatizadeh, Vahid; Barnes, Glenn; Jones, Steve; Rusche, James R.; Gottesfeld, Joel M.; Pook, Mark A.

    2011-01-01

    Friedreich ataxia (FRDA) is an inherited neurodegenerative disorder caused by GAA repeat expansion within the FXN gene, leading to epigenetic changes and heterochromatin-mediated gene silencing that result in a frataxin protein deficit. Histone deacetylase (HDAC) inhibitors, including pimelic o-aminobenzamide compounds 106, 109 and 136, have previously been shown to reverse FXN gene silencing in short-term studies of FRDA patient cells and a knock-in mouse model, but the functional consequences of such therapeutic intervention have thus far not been described. We have now investigated the long-term therapeutic effects of 106, 109 and 136 in our GAA repeat expansion mutation-containing YG8R FRDA mouse model. We show that there is no overt toxicity up to 5 months of treatment and there is amelioration of the FRDA-like disease phenotype. Thus, while the neurological deficits of this model are mild, 109 and 106 both produced an improvement of motor coordination, whereas 109 and 136 produced increased locomotor activity. All three compounds increased global histone H3 and H4 acetylation of brain tissue, but only 109 significantly increased acetylation of specific histone residues at the FXN locus. Effects on FXN mRNA expression in CNS tissues were modest, but 109 significantly increased frataxin protein expression in brain tissue. 109 also produced significant increases in brain aconitase enzyme activity, together with reduction of neuronal pathology of the dorsal root ganglia (DRG). Overall, these results support further assessment of HDAC inhibitors for treatment of Friedreich ataxia. PMID:21397024

  5. 2-Benzazolyl-4-Piperazin-1-Ylsulfonylbenzenecarbohydroxamic Acids as Novel Selective Histone Deacetylase-6 Inhibitors with Antiproliferative Activity

    PubMed Central

    Wang, Lei; Kofler, Marina; Brosch, Gerald; Melesina, Jelena; Sippl, Wolfgang; Martinez, Elisabeth D.; Easmon, Johnny

    2015-01-01

    We have screened our compound collection in an established cell based assay that measures the derepression of an epigenetically silenced transgene, the locus derepression assay. The screen led to the identification of 4-[4-(1-methylbenzimidazol-2-yl)piperazin-1-yl]sulfonylbenzenecarbohydroxamic acid (9b) as an active which was found to inhibit HDAC1. In initial structure activity relationships study, the 1-methylbenzimidazole ring was replaced by the isosteric heterocycles benzimidazole, benzoxazole, and benzothiazole and the position of the hydroxamic acid substituent on the phenyl ring was varied. Whereas compounds bearing a para substituted hydroxamic acid (9a-d) were active HDAC inhibitors, the meta substituted analogues (8a-d) were appreciably inactive. Compounds 9a-d selectively inhibited HDAC6 (IC50 = 0.1–1.0μM) over HDAC1 (IC50 = 0.9–6μM) and moreover, also selectively inhibited the growth of lung cancer cells vs. patient matched normal cells. The compounds induce a cell cycle arrest in the S-phase while induction of apoptosis is neglible as compared to controls. Molecular modeling studies uncovered that the MM-GBSA energy for interaction of 9a-d with HDAC6 was higher than for HDAC1 providing structural rationale for the HDAC6 selectivity. PMID:26698121

  6. BET and HDAC inhibitors induce similar genes and biological effects and synergize to kill in Myc-induced murine lymphoma

    PubMed Central

    Bhadury, Joydeep; Nilsson, Lisa M.; Veppil Muralidharan, Somsundar; Green, Lydia C.; Li, Zhoulei; Gesner, Emily M.; Hansen, Henrik C.; Keller, Ulrich B.; McLure, Kevin G.; Nilsson, Jonas A.

    2014-01-01

    The bromodomain and extraterminal (BET) domain family of proteins binds to acetylated lysines on histones and regulates gene transcription. Recently, BET inhibitors (BETi) have been developed that show promise as potent anticancer drugs against various solid and hematological malignancies. Here we show that the structurally novel and orally bioavailable BET inhibitor RVX2135 inhibits proliferation and induces apoptosis of lymphoma cells arising in Myc-transgenic mice in vitro and in vivo. We find that BET inhibition exhibits broad transcriptional effects in Myc-transgenic lymphoma cells affecting many transcription factor networks. By examining the genes induced by BETi, which have largely been ignored to date, we discovered that these were similar to those induced by histone deacetylase inhibitors (HDACi). HDACi also induced cell-cycle arrest and cell death of Myc-induced murine lymphoma cells and synergized with BETi. Our data suggest that BETi sensitize Myc-overexpressing lymphoma cells partly by inducing HDAC-silenced genes, and suggest synergistic and therapeutic combinations by targeting the genetic link between BETi and HDACi. PMID:24979794

  7. 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.

  8. 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

    2015-08-01

    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.

  9. 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

  10. Can Small Chemical Modifications of Natural Pan-inhibitors Modulate the Biological Selectivity? The Case of Curcumin Prenylated Derivatives Acting as HDAC or mPGES-1 Inhibitors.

    PubMed

    Iranshahi, Mehrdad; Chini, Maria Giovanna; Masullo, Milena; Sahebkar, Amirhossein; Javidnia, Azita; Chitsazian Yazdi, Mahsa; Pergola, Carlo; Koeberle, Andreas; Werz, Oliver; Pizza, Cosimo; Terracciano, Stefania; Piacente, Sonia; Bifulco, Giuseppe

    2015-12-24

    Curcumin, or diferuloylmethane, a polyphenolic molecule isolated from the rhizome of Curcuma longa, is reported to modulate multiple molecular targets involved in cancer and inflammatory processes. On the basis of its pan-inhibitory characteristics, here we show that simple chemical modifications of the curcumin scaffold can regulate its biological selectivity. In particular, the curcumin scaffold was modified with three types of substituents at positions C-1, C-8, and/or C-8' [C5 (isopentenyl, 5-8), C10 (geranyl, 9-12), and C15 (farnesyl, 13, 14)] in order to make these molecules more selective than the parent compound toward two specific targets: histone deacetylase (HDAC) and microsomal prostaglandin E2 synthase-1 (mPGES-1). From combined in silico and in vitro analyses, three selective inhibitors by proper substitution at position 8 were revealed. Compound 13 has improved HDAC inhibitory activity and selectivity with respect to the parent compound, while 5 and 9 block the mPGES-1 enzyme. We hypothesize about the covalent interaction of curcumin, 5, and 9 with the mPGES-1 binding site. PMID:26588603

  11. Can Small Chemical Modifications of Natural Pan-inhibitors Modulate the Biological Selectivity? The Case of Curcumin Prenylated Derivatives Acting as HDAC or mPGES-1 Inhibitors.

    PubMed

    Iranshahi, Mehrdad; Chini, Maria Giovanna; Masullo, Milena; Sahebkar, Amirhossein; Javidnia, Azita; Chitsazian Yazdi, Mahsa; Pergola, Carlo; Koeberle, Andreas; Werz, Oliver; Pizza, Cosimo; Terracciano, Stefania; Piacente, Sonia; Bifulco, Giuseppe

    2015-12-24

    Curcumin, or diferuloylmethane, a polyphenolic molecule isolated from the rhizome of Curcuma longa, is reported to modulate multiple molecular targets involved in cancer and inflammatory processes. On the basis of its pan-inhibitory characteristics, here we show that simple chemical modifications of the curcumin scaffold can regulate its biological selectivity. In particular, the curcumin scaffold was modified with three types of substituents at positions C-1, C-8, and/or C-8' [C5 (isopentenyl, 5-8), C10 (geranyl, 9-12), and C15 (farnesyl, 13, 14)] in order to make these molecules more selective than the parent compound toward two specific targets: histone deacetylase (HDAC) and microsomal prostaglandin E2 synthase-1 (mPGES-1). From combined in silico and in vitro analyses, three selective inhibitors by proper substitution at position 8 were revealed. Compound 13 has improved HDAC inhibitory activity and selectivity with respect to the parent compound, while 5 and 9 block the mPGES-1 enzyme. We hypothesize about the covalent interaction of curcumin, 5, and 9 with the mPGES-1 binding site.

  12. Metabolism-related liabilities of a potent histone deacetylase (HDAC) inhibitor and relevance of the route of administration on its metabolic fate.

    PubMed

    Fonsi, M; Fiore, F; Jones, P; Kinzel, O; Laufer, R; Rowley, M; Monteagudo, E

    2009-10-01

    Compound A [1-methyl-N-{(1S)-1-[5-(2-naphthyl)-1H-imidazol-2-yl]-7-oxooctyl}piperidine-4-carboxamide is a potent class I histone deacetylase (HDAC) inhibitor that demonstrated good antiproliferative activity against human tumour cell lines of different origin. This compound showed high in vivo clearance in rats (160 ml min(-1) kg(-1)) due to metabolism. The main metabolite detected in urine after intravenous dosing was characterized as a dihydrohydroxy S-mercapturic acid conjugate. Following oral dosing, however, the mercapturic acid derivative was no longer the main metabolite but the major metabolites were mono- and di-glucuronide conjugates of oxidized species having a mass shift of +34 m/z with respect to the parent. Comparison of plasma concentration after intra-arterial infusion and intravenous infusion and incubation with microsomes from different tissues (liver, kidney, small intestine and lung) in the presence of beta-nicotinamide adenine dinucleotide phosphate (NADPH) indicated that the compound was highly cleared by the lung. Oxidation of the naphthalene moiety was demonstrated to be the cause of the high in vivo clearance of compound A and the potential for bioactivation of this group was flagged.

  13. A series of novel, potent, and selective histone deacetylase inhibitors.

    PubMed

    Jones, Philip; Altamura, Sergio; Chakravarty, Prasun K; Cecchetti, Ottavia; De Francesco, Raffaele; Gallinari, Paola; Ingenito, Raffaele; Meinke, Peter T; Petrocchi, Alessia; Rowley, Michael; Scarpelli, Rita; Serafini, Sergio; Steinkühler, Christian

    2006-12-01

    Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in clinical trials. A structurally novel series of HDAC inhibitors based on the natural cyclic tetrapeptide Apicidin is described. Selected screening of the sample collection looking for L-2-amino-8-oxodecanoic acid (L-Aoda) derivatives identified a small acyclic lead molecule 1 with the unusual ketone zinc binding group. SAR studies around this lead resulted in optimization to potent, low molecular weight, selective, non-hydroxamic acid HDAC inhibitors, equipotent to current clinical candidates.

  14. 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

    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

    2016-05-15

    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

  15. 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

  16. Hybrids from 4-anilinoquinazoline and hydroxamic acid as dual inhibitors of vascular endothelial growth factor receptor-2 and histone deacetylase.

    PubMed

    Peng, Fan-Wei; Wu, Ting-Ting; Ren, Zi-Wei; Xue, Jia-Yu; Shi, Lei

    2015-11-15

    A series of hybrids derived from 4-anilinoquinazoline and hydroxamic acid were designed, synthesized, and evaluated as dual inhibitors of vascular endothelia growth factor receptor-2 (VEGFR-2) tyrosine kinase and histone deacetylase (HDAC). Most of these compounds exhibited potent HDAC inhibition and moderate VEGFR-2 inhibition. Among them, compound 6l exhibited the most potent inhibitory activities against VEGFR-2 (IC50=84 nM) and HDAC (IC50=2.8 nM). It also showed the most potent antiproliferative ability against MCF-7, a human breast cancer line, with IC50 of 1.2 μM. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction of compound 6l at the active binding sites of VEGFR-2 and HDAC. PMID:26475519

  17. HDAC up-regulation in early colon field carcinogenesis is involved in cell tumorigenicity through regulation of chromatin structure.

    PubMed

    Stypula-Cyrus, Yolanda; Damania, Dhwanil; Kunte, Dhananjay P; Cruz, Mart Dela; Subramanian, Hariharan; Roy, Hemant K; Backman, Vadim

    2013-01-01

    Normal cell function is dependent on the proper maintenance of chromatin structure. Regulation of chromatin structure is controlled by histone modifications that directly influence chromatin architecture and genome function. Specifically, the histone deacetylase (HDAC) family of proteins modulate chromatin compaction and are commonly dysregulated in many tumors, including colorectal cancer (CRC). However, the role of HDAC proteins in early colorectal carcinogenesis has not been previously reported. We found HDAC1, HDAC2, HDAC3, HDAC5, and HDAC7 all to be up-regulated in the field of human CRC. Furthermore, we observed that HDAC2 up-regulation is one of the earliest events in CRC carcinogenesis and observed this in human field carcinogenesis, the azoxymethane-treated rat model, and in more aggressive colon cancer cell lines. The universality of HDAC2 up-regulation suggests that HDAC2 up-regulation is a novel and important early event in CRC, which may serve as a biomarker. HDAC inhibitors (HDACIs) interfere with tumorigenic HDAC activity; however, the precise mechanisms involved in this process remain to be elucidated. We confirmed that HDAC inhibition by valproic acid (VPA) targeted the more aggressive cell line. Using nuclease digestion assays and transmission electron microscopy imaging, we observed that VPA treatment induced greater changes in chromatin structure in the more aggressive cell line. Furthermore, we used the novel imaging technique partial wave spectroscopy (PWS) to quantify nanoscale alterations in chromatin. We noted that the PWS results are consistent with the biological assays, indicating a greater effect of VPA treatment in the more aggressive cell type. Together, these results demonstrate the importance of HDAC activity in early carcinogenic events and the unique role of higher-order chromatin structure in determining cell tumorigenicity.

  18. 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.

  19. Identifying Novel Type ZBGs and Nonhydroxamate HDAC Inhibitors Through a SVM Based Virtual Screening Approach.

    PubMed

    Liu, X H; Song, H Y; Zhang, J X; Han, B C; Wei, X N; Ma, X H; Cui, W K; Chen, Y Z

    2010-05-17

    Histone deacetylase inhibitors (HDACi) have been successfully used for the treatment of cancers and other diseases. Search for novel type ZBGs and development of non-hydroxamate HDACi has become a focus in current research. To complement this, it is desirable to explore a virtual screening (VS) tool capable of identifying different types of potential inhibitors from large compound libraries with high yields and low false-hit rates similar to HTS. This work explored the use of support vector machines (SVM) combined with our newly developed putative non-inhibitor generation method as such a tool. SVM trained by 702 pre-2008 hydroxamate HDACi and 64334 putative non-HDACi showed good yields and low false-hit rates in cross-validation test and independent test using 220 diverse types of HDACi reported since 2008. The SVM hit rates in scanning 13.56 M PubChem and 168K MDDR compounds are comparable to HTS rates. Further structural analysis of SVM virtual hits suggests its potential for identification of non-hydroxamate HDACi. From this analysis, a series of novel ZBG and cap groups were proposed for HDACi design.

  20. 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.

  1. 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.

  2. KE108-conjugated unimolecular micelles loaded with a novel HDAC inhibitor thailandepsin-A for targeted neuroendocrine cancer therapy.

    PubMed

    Chen, Guojun; Jaskula-Sztul, Renata; Harrison, April; Dammalapati, Ajitha; Xu, Wenjin; Cheng, Yiqiang; Chen, Herbert; Gong, Shaoqin

    2016-08-01

    Neuroendocrine (NE) cancers can cause significant patient morbidity. Besides surgery, there are no curative treatments for NE cancers and their metastases, emphasizing the need for the development of other forms of therapy. In this study, multifunctional unimolecular micelles were developed for targeted NE cancer therapy. The unimolecular micelles were formed by multi-arm star amphiphilic block copolymer poly(amidoamine)-poly(valerolactone)-poly(ethylene glycol) conjugated with KE108 peptide and Cy5 dye (abbreviated as PAMAM-PVL-PEG-KE108/Cy5). The unimolecular micelles with a spherical core-shell structure exhibited a uniform size distribution and excellent stability. The hydrophobic drug thailandepsin-A (TDP-A), a recently discovered HDAC inhibitor, was physically encapsulated into the hydrophobic core of the micelles. KE108 peptide, a somatostatin analog possessing high affinity for all five subtypes of somatostatin receptors (SSTR 1-5), commonly overexpressed in NE cancer cells, was used for the first time as an NE cancer targeting ligand. KE108 exhibited superior targeting abilities compared to other common somatostatin analogs, such as octreotide, in NE cancer cell lines. The in vitro assays demonstrated that the TDP-A-loaded, KE108-targeted micelles exhibited the best capabilities in suppressing NE cancer cell growth. Moreover, the in vivo near-infrared fluorescence imaging on NE-tumor-bearing nude mice showed that KE108-conjugated micelles exhibited the greatest tumor accumulation due to their passive targeting and active targeting capabilities. Finally, TDP-A-loaded and KE108-conjugated micelles possessed the best anticancer efficacy without detectable systemic toxicity. Thus, these novel TDP-A-loaded and KE108-conjugated unimolecular micelles offer a promising approach for targeted NE cancer therapy. PMID:27156249

  3. 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

  4. The HDAC inhibitor SAHA improves depressive-like behavior of CRTC1-deficient mice: Possible relevance for treatment-resistant depression.

    PubMed

    Meylan, Elsa M; Halfon, Olivier; Magistretti, Pierre J; Cardinaux, Jean-René

    2016-08-01

    Major depression is a highly complex disabling psychiatric disorder affecting millions of people worldwide. Despite the availability of several classes of antidepressants, a substantial percentage of patients are unresponsive to these medications. A better understanding of the neurobiology of depression and the mechanisms underlying antidepressant response is thus critically needed. We previously reported that mice lacking CREB-regulated transcription coactivator 1 (CRTC1) exhibit a depressive-like phenotype and a blunted antidepressant response to the selective serotonin reuptake inhibitor fluoxetine. In this study, we similarly show that Crtc1(-/-) mice are resistant to the antidepressant effect of chronic desipramine in a behavioral despair paradigm. Supporting the blunted response to this tricyclic antidepressant, we found that desipramine does not significantly increase the expression of Bdnf and Nr4a1-3 in the hippocampus and prefrontal cortex of Crtc1(-/-) mice. Epigenetic regulation of neuroplasticity gene expression has been associated with depression and antidepressant response, and histone deacetylase (HDAC) inhibitors have been shown to have antidepressant-like properties. Here, we show that unlike conventional antidepressants, chronic systemic administration of the HDAC inhibitor SAHA partially rescues the depressive-like behavior of Crtc1(-/-) mice. This behavioral effect is accompanied by an increased expression of Bdnf, but not Nr4a1-3, in the prefrontal cortex of these mice, suggesting that this epigenetic intervention restores the expression of a subset of genes by acting downstream of CRTC1. These findings suggest that CRTC1 alterations may be associated with treatment-resistant depression, and support the interesting possibility that targeting HDACs may be a useful therapeutic strategy in antidepressant development. PMID:26970016

  5. 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

  6. 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.

  7. 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.

  8. Class I HDAC activity is required for renal protection and regeneration after acute kidney injury.

    PubMed

    Tang, Jinhua; Yan, Yanli; Zhao, Ting C; Gong, Rujun; Bayliss, George; Yan, Haidong; Zhuang, Shougang

    2014-08-01

    Activation of histone deacetylases (HDACs) is required for renal epithelial cell proliferation and kidney development. However, their role in renal tubular cell survival and regeneration after acute kidney injury (AKI) remains unclear. In this study, we demonstrated that all class I HDAC isoforms (1, 2, 3, and 8) were expressed in the renal epithelial cells of the mouse kidney. Inhibition of class I HDACs with MS-275, a highly selective inhibitor, resulted in more severe tubular injury in the mouse model of AKI induced by folic acid or rhabdomyolysis, as indicated by worsening renal dysfunction, increased neutrophil gelatinase-associated lipocalin expression, and enhanced apoptosis and caspase-3 activation. Blocking class I HDAC activity also impaired renal regeneration as evidenced by decreased expression of renal Pax-2, vimentin, and proliferating cell nuclear antigen. Injury to the kidney is accompanied by increased phosphorylation of epidermal growth factor receptor (EGFR), signal transducers and activators of transcription 3 (STAT3), and Akt. Inhibition of class I HDACs suppressed EGFR phosphorylation as well as reduced its expression. MS-275 was also effective in inhibiting STAT3 and Akt phosphorylation, but this treatment did not affect their expression levels. Taken together, these data suggest that the class I HDAC activity contributes to renal protection and functional recovery and is required for renal regeneration after AKI. Furthermore, renal EGFR signaling is subject to regulation by this class of HDACs.

  9. The HDAC Inhibitors Scriptaid and LBH589 Combined with the Oncolytic Virus Delta24-RGD Exert Enhanced Anti-Tumor Efficacy in Patient-Derived Glioblastoma Cells

    PubMed Central

    Berghauser Pont, Lotte M.E.; Kleijn, Anne; Kloezeman, Jenneke J.; van den Bossche, Wouter; Kaufmann, Johanna K.; de Vrij, Jeroen; Leenstra, Sieger; Dirven, Clemens M.F.; Lamfers, Martine L.M.

    2015-01-01

    Background A phase I/II trial for glioblastoma with the oncolytic adenovirus Delta24-RGD was recently completed. Delta24-RGD conditionally replicates in cells with a disrupted retinoblastoma-pathway and enters cells via αvβ3/5 integrins. Glioblastomas are differentially sensitive to Delta24-RGD. HDAC inhibitors (HDACi) affect integrins and share common cell death pathways with Delta24-RGD. We studied the combination treatment effects of HDACi and Delta24-RGD in patient-derived glioblastoma stem-like cells (GSC), and we determined the most effective HDACi. Methods SAHA, Valproic Acid, Scriptaid, MS275 and LBH589 were combined with Delta24-RGD in fourteen distinct GSCs. Synergy was determined by Chou Talalay method. Viral infection and replication were assessed using luciferase and GFP encoding vectors and hexon-titration assays. Coxsackie adenovirus receptor and αvβ3 integrin levels were determined by flow cytometry. Oncolysis and mechanisms of cell death were studied by viability, caspase-3/7, LDH and LC3B/p62, phospho-p70S6K. Toxicity was studied on normal human astrocytes. MGMT promotor methylation status, TCGA classification, Rb-pathway and integrin gene expression levels were assessed as markers of responsiveness. Results Scriptaid and LBH589 acted synergistically with Delta24-RGD in approximately 50% of the GSCs. Both drugs moderately increased αvβ3 integrin levels and viral infection in responding but not in non-responding GSCs. LBH589 moderately increased late viral gene expression, however, virus titration revealed diminished viral progeny production by both HDACi, Scriptaid augmented caspase-3/7 activity, LC3B conversion, p62 and phospho-p70S6K consumption, as well as LDH levels. LBH589 increased LDH and phospho-p70S6K consumption. Responsiveness correlated with expression of various Rb-pathway genes and integrins. Combination treatments induced limited toxicity to human astrocytes. Conclusion LBH589 and Scriptaid combined with Delta24-RGD revealed

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

    PubMed

    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 p21(Cip1) and p27(Kip1) 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.

  11. HDAC3 But not HDAC2 Mediates Visual Experience-Dependent Radial Glia Proliferation in the Developing Xenopus Tectum

    PubMed Central

    Gao, Juanmei; Ruan, Hangze; Qi, Xianjie; Tao, Yi; Guo, Xia; Shen, Wanhua

    2016-01-01

    Radial glial cells (RGs) are one of the important progenitor cells that can differentiate into neurons or glia to form functional neural circuits in the developing central nervous system (CNS). Histone deacetylases (HDACs) has been associated with visual activity dependent changes in BrdU-positive progenitor cells in the developing brain. We previously have shown that HDAC1 is involved in the experience-dependent proliferation of RGs. However, it is less clear whether two other members of class I HDACs, HDAC2 and HDAC3, are involved in the regulation of radial glia proliferation. Here, we reported that HDAC2 and HDAC3 expression were developmentally regulated in tectal cells, especially in the ventricular layer of the BLBP-positive RGs. Pharmacological blockade using an inhibitor of class I HDACs, MS-275, decreased the number of BrdU-positive dividing progenitor cells. Specific knockdown of HDAC3 but not HDAC2 decreased the number of BrdU- and BLBP-labeled cells, suggesting that the proliferation of radial glia was selectively mediated by HDAC3. Visual deprivation induced selective augmentation of histone H4 acetylation at lysine 16 in BLBP-positive cells. Furthermore, the visual deprivation-induced increase in BrdU-positive cells was partially blocked by HDAC3 downregulation but not by HDAC2 knockdown at stage 49 tadpoles. These data revealed a specific role of HDAC3 in experience-dependent radial glia proliferation during the development of Xenopus tectum. PMID:27729849

  12. 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.

  13. Plant HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells

    PubMed Central

    2012-01-01

    Background Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells. Methods Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27). The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays. Results Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis. Conclusion Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (−692 to −684) region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating cell cycle progression

  14. 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

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

    PubMed

    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; Schildhaus, Hans-Ulrich

    2016-04-01

    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-Glo(TM) 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.

  16. Separate and Combined Effects of DNMT and HDAC Inhibitors in Treating Human Multi-Drug Resistant Osteosarcoma HosDXR150 Cell Line

    PubMed Central

    Capobianco, Enrico; Mora, Antonio; La Sala, Dario; Roberti, Annalisa; Zaki, Nazar; Badidi, Elarbi; Taranta, Monia; Cinti, Caterina

    2014-01-01

    Understanding the molecular mechanisms underlying multi-drug resistance (MDR) is one of the major challenges in current cancer research. A phenomenon which is common to both intrinsic and acquired resistance, is the aberrant alteration of gene expression in drug-resistant cancers. Although such dysregulation depends on many possible causes, an epigenetic characterization is considered a main driver. Recent studies have suggested a direct role for epigenetic inactivation of genes in determining tumor chemo-sensitivity. We investigated the effects of the inhibition of DNA methyltransferase (DNMT) and hystone deacethylase (HDAC), considered to reverse the epigenetic aberrations and lead to the re-expression of de novo methylated genes in MDR osteosarcoma (OS) cells. Based on our analysis of the HosDXR150 cell line, we found that in order to reduce cell proliferation, co-treatment of MDR OS cells with DNMT (5-Aza-dC, DAC) and HDAC (Trichostatin A, TSA) inhibitors is more effective than relying on each treatment alone. In re-expressing epigenetically silenced genes induced by treatments, a very specific regulation takes place which suggests that methylation and de-acetylation have occurred either separately or simultaneously to determine MDR OS phenotype. In particular, functional relationships have been reported after measuring differential gene expression, indicating that MDR OS cells acquired growth and survival advantage by simultaneous epigenetic inactivation of both multiple p53-independent apoptotic signals and osteoblast differentiation pathways. Furthermore, co-treatment results more efficient in inducing the re-expression of some main pathways according to the computed enrichment, thus emphasizing its potential towards representing an effective therapeutic option for MDR OS. PMID:24756038

  17. Two New Pimelic Diphenylamide HDAC Inhibitors Induce Sustained Frataxin Upregulation in Cells from Friedreich's Ataxia Patients and in a Mouse Model

    PubMed Central

    Rai, Myriam; Soragni, Elisabetta; Chou, C. James; Barnes, Glenn; Jones, Steve; Rusche, James R.; Gottesfeld, Joel M.; Pandolfo, Massimo

    2010-01-01

    Background Friedreich's ataxia (FRDA), the most common recessive ataxia in Caucasians, is due to severely reduced levels of frataxin, a highly conserved protein, that result from a large GAA triplet repeat expansion within the first intron of the frataxin gene (FXN). Typical marks of heterochromatin are found near the expanded GAA repeat in FRDA patient cells and mouse models. Histone deacetylase inhibitors (HDACIs) with a pimelic diphenylamide structure and HDAC3 specificity can decondense the chromatin structure at the FXN gene and restore frataxin levels in cells from FRDA patients and in a GAA repeat based FRDA mouse model, KIKI, providing an appealing approach for FRDA therapeutics. Methodology/Principal Findings In an effort to further improve the pharmacological profile of pimelic diphenylamide HDACIs as potential therapeutics for FRDA, we synthesized additional compounds with this basic structure and screened them for HDAC3 specificity. We characterized two of these compounds, 136 and 109, in FRDA patients' peripheral blood lymphocytes and in the KIKI mouse model. We tested their ability to upregulate frataxin at a range of concentrations in order to determine a minimal effective dose. We then determined in both systems the duration of effect of these drugs on frataxin mRNA and protein, and on total and local histone acetylation. The effects of these compounds exceeded the time of direct exposure in both systems. Conclusions/Significance Our results support the pre-clinical development of a therapeutic approach based on pimelic diphenylamide HDACIs for FRDA and provide information for the design of future human trials of these drugs, suggesting an intermittent administration of the drug. PMID:20098685

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

    PubMed

    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; Schildhaus, Hans-Ulrich

    2016-04-01

    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-Glo(TM) 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

  19. 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.

  20. p21(Waf1) is required for cellular senescence but not for cell cycle arrest induced by the HDAC inhibitor sodium butyrate.

    PubMed

    Romanov, V S; Abramova, M V; Svetlikova, S B; Bykova, T V; Zubova, S G; Aksenov, N D; Fornace, A J; Pospelova, T V; Pospelov, V A

    2010-10-01

    Cell senescence is characterized by senescent morphology and permanent loss of proliferative potential. HDAC inhibitors (HDACI) induce senescence and/or apoptosis in many types of tumor cells. Here, we studied the role of cyclin-kinase inhibitor p21(waf1) (Cdkn1n gene) in cell cycle arrest, senescence markers (cell hypertrophy, SA-βGal staining and accumulation of γH2AX foci) in p21(Waf1+/+) versus p21(Waf1-/-) mouse embryonic fibroblast cells transformed with E1A and cHa-Ras oncogenes (mERas). While short treatment with the HDACI sodium butyrate (NaB) induced a reversible G(1) cell cycle arrest in both parental and p21(Waf1-/-) cells, long-term treatment led to dramatic changes in p21(Waf1+/+) cells only: cell cycle arrest became irreversible and cells become hypertrophic, SA-βGal-positive and accumulated γH2AX foci associated with mTORC1 activation. The p21(Waf1+/+) cells lost their ability to migrate into the wound and through a porous membrane. Suppression of migration was accompanied by accumulation of vinculin-staining focal adhesions and Ser3-phosphorylation of cofilin, incapable for F-actin depolymerization. In contrast, the knockout of the p21(Waf1) abolished most of the features of NaB-induced senescence, including irreversibility of cell cycle arrest, hypertrophy, additional focal adhesions and block of migration, γH2AX foci accumulation and SA-βGal staining. Rapamycin, a specific inhibitor of mTORC1 kinase, decreased cellular hypertrophy, canceled coffilin phosphorylation and partially restored cell migration in p21(Waf1+/+) cells. Taken together, our data indicate a new role of p21(Waf1) in cell senescence, which may be connected not only with execution of cell cycle arrest, but also with the development of mTOR-dependent markers of cellular senescence.

  1. Transcriptional Regulation of Endothelial Arginase 2 by HDAC2

    PubMed Central

    Pandey, Deepesh; Sikka, Gautam; Bergman, Yehudit; Kim, Jae Hyung; Ryoo, Sungwoo

    2015-01-01

    Objective Arginase 2 is a critical target in atherosclerosis as it controls endothelial NO, proliferation, fibrosis, and inflammation. Regulators of Arg2 transcription in the endothelium have not been characterized. The goal of the current study is to determine the role of specific HDACs in the regulation of endothelial Arg2 transcription and endothelial function. Approach and Results The HDAC inhibitor, trichostatin A (TSA) increased levels of Arg2 mRNA, protein, and activity in both HAEC and mouse aortic rings. These changes occurred with both time- and dose-dependent patterns, and resulted in Arg2-dependent endothelial dysfunction. TSA and the atherogenic stimulus OxLDL enhanced the activity of common promoter regions of Arg2. HDAC inhibition with TSA also decreased endothelial NO and these effects were blunted by arginase inhibition. Non-selective class I HDAC inhibitors enhanced Arg2 expression, while the only selective inhibitor that increased Arg2 expression was mocetinostat (MGCD) – a selective inhibitor of HDACs 1 and 2. Additionally, mouse aortic rings pre-incubated with MGCD exhibited dysfunctional relaxation. Overexpression of HDAC2 (but not HDAC 1, 3 or 8) cDNA in HAEC suppressed Arg2 expression in a concentration-dependent manner, and siRNA knockdown of HDAC2 enhanced Arg2 expression. Chromatin immunoprecipitation indicated direct binding of HDAC2 to the Arg2 promoter, and HDAC2 overexpression in HAEC blocked OxLDL-mediated activation of the Arg2 promoter. Finally, overexpression of HDAC2 blocked OxLDL-mediated vascular dysfunction. Conclusions HDAC2 is a critical regulator of Arg2 expression and thereby endothelial NO and endothelial function. Overexpression or activation of HDAC2 represents a novel therapy for endothelial dysfunction and atherosclerosis. PMID:24833798

  2. 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

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

    PubMed Central

    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

    2013-01-01

    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. PMID:23505062

  4. Synergistic neuroprotective effects of lithium and valproic acid or other histone deacetylase inhibitors in neurons: roles of glycogen synthase kinase-3 inhibition.

    PubMed

    Leng, Yan; Liang, Min-Huei; Ren, Ming; Marinova, Zoya; Leeds, Peter; Chuang, De-Maw

    2008-03-01

    Lithium and valproic acid (VPA) are two primary drugs used to treat bipolar mood disorder and have frequently been used in combination to treat bipolar patients resistant to monotherapy with either drug. Lithium, a glycogen synthase kinase-3 (GSK-3) inhibitor, and VPA, a histone deacetylase (HDAC) inhibitor, have neuroprotective effects. The present study was undertaken to demonstrate synergistic neuroprotective effects when both drugs were coadministered. Pretreatment of aging cerebellar granule cells with lithium or VPA alone provided little or no neuroprotection against glutamate-induced cell death. However, copresence of both drugs resulted in complete blockade of glutamate excitotoxicity. Combined treatment with lithium and VPA potentiated serine phosphorylation of GSK-3 alpha and beta isoforms and inhibition of GSK-3 enzyme activity. Transfection with GSK-3alpha small interfering RNA (siRNA) and/or GSK-3beta siRNA mimicked the ability of lithium to induce synergistic protection with VPA. HDAC1 siRNA or other HDAC inhibitors (phenylbutyrate, sodium butyrate or trichostatin A) also caused synergistic neuroprotection together with lithium. Moreover, combination of lithium and HDAC inhibitors potentiated beta-catenin-dependent, Lef/Tcf-mediated transcriptional activity. An additive increase in GSK-3 serine phosphorylation was also observed in mice chronically treated with lithium and VPA. Together, for the first time, our results demonstrate synergistic neuroprotective effects of lithium and HDAC inhibitors and suggest that GSK-3 inhibition is a likely molecular target for the synergistic neuroprotection. Our results may have implications for the combined use of lithium and VPA in treating bipolar disorder. Additionally, combined use of both drugs may be warranted for clinical trials to treat glutamate-related neurodegenerative diseases.

  5. 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

  6. 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

  7. Heterocyclics as corrosion inhibitors for acid media

    SciTech Connect

    Ajmal, M.; Khan, M.A.W.; Ahmad, S.; Quraishi, M.A.

    1996-12-01

    The available literature on the use of heterocyclic compounds as corrosion inhibitors in acid media has been reviewed. It has been noted that the workers in this field have either used sulfur or nitrogen containing heterocyclic compounds for studying inhibition action. The authors have synthesized compounds containing sulfur and nitrogen both in the same ring and studied their inhibition action in acid media. These compounds were found to be better inhibitors than those containing either atoms alone.

  8. Search for novel histone deacetylase inhibitors. Part II: design and synthesis of novel isoferulic acid derivatives.

    PubMed

    Lu, Wen; Wang, Fang; Zhang, Tao; Dong, Jinyun; Gao, Hongping; Su, Ping; Shi, Yaling; Zhang, Jie

    2014-05-01

    Previously, we described the discovery of potent ferulic acid-based histone deacetylase inhibitors (HDACIs) with halogeno-acetanilide as novel surface recognition moiety (SRM). In order to improve the affinity and activity of these HDACIs, twenty seven isoferulic acid derivatives were described herein. The majority of title compounds displayed potent HDAC inhibitory activity. In particular, IF5 and IF6 exhibited significant enzymatic inhibitory activities, with IC50 values of 0.73 ± 0.08 and 0.57 ± 0.16 μM, respectively. Furthermore, these compounds showed moderate antiproliferative activity against human cancer cells. Especially, IF6 displayed promising profile as an antitumor candidate with IC50 value of 3.91 ± 0.97 μM against HeLa cells. The results indicated that these isoferulic acid derivatives could serve as promising lead compounds for further optimization. PMID:24702857

  9. Development of novel ferulic acid derivatives as potent histone deacetylase inhibitors.

    PubMed

    Wang, Fang; Lu, Wen; Zhang, Tao; Dong, Jinyun; Gao, Hongping; Li, Pengfei; Wang, Sicen; Zhang, Jie

    2013-11-15

    Histone deacetylase inhibitors (HDACIs) offer a promising strategy for cancer therapy. The discovery of potent ferulic acid-based HDACIs with hydroxamic acid or 2-aminobenzamide group as zinc binding group was reported. The halogeno-acetanilide was introduced as novel surface recognition moiety (SRM). The majority of title compounds displayed potent HDAC inhibitory activity. In particular, FA6 and FA16 exhibited significant enzymatic inhibitory activities, with IC50 values of 3.94 and 2.82 μM, respectively. Furthermore, these compounds showed moderate antiproliferative activity against a panel of human cancer cells. FA17 displayed promising profile as an antitumor candidate. The results indicated that these ferulic acid derivatives could serve as promising lead compounds for further optimization. PMID:24095016

  10. 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. PMID:26447190

  11. HDAC1 nuclear export induced by pathological conditions is essential for the onset of axonal damage

    PubMed Central

    Kim, Jin Young; Shen, Siming; Dietz, Karen; He, Ye; Howell, Owain; Reynolds, Richard; Casaccia, Patrizia

    2010-01-01

    Histone deacetylase 1 (HDAC1) is a nuclear enzyme involved in transcriptional repression. We report here that cytosolic HDAC1 is detected in damaged axons in brains of human patients with Multiple Sclerosis and of mice with cuprizone-induced demyelination, ex vivo models of demyelination and in cultured neurons exposed to glutamate and TNF-α. Nuclear export of HDAC1 is mediated by the interaction with the nuclear receptor CRM-1 and leads to impaired mitochondrial transport. The formation of complexes between exported HDAC1 and members of the kinesin family of motor proteins hinders the interaction with cargo molecules thereby inhibiting mitochondrial movement and inducing localized beadings. This effect is prevented by inhibiting HDAC1 nuclear export with leptomycin B, treating neurons with pharmacological inhibitors of HDAC activity or silencing HDAC1 but not other HDAC isoforms. Together these data identify nuclear export of HDAC1 as a critical event for impaired mitochondrial transport in damaged neurons. PMID:20037577

  12. Sodium butyrate, a HDAC inhibitor ameliorates eNOS, iNOS and TGF-β1-induced fibrogenesis, apoptosis and DNA damage in the kidney of juvenile diabetic rats.

    PubMed

    Khan, Sabbir; Jena, Gopabandhu

    2014-11-01

    Recent reports highlighted the role of histone deacetylases (HDACs) in the pathogenesis of diabetic nephropathy (DN), but the exact molecular mechanisms by which HDAC inhibitors ameliorate DN still remain unclear. The present study was aimed to investigate the renoprotective effects of sodium butyrate (NaB) in diabetes-induced renal damages, apoptosis and fibrosis in juvenile rats. Diabetes was induced by single injection of STZ (60mg/kg), whereas NaB (500mg/kg/day) was administrated for 21days by i.p. route in a pre- and post-treatment schedule. End-points of evaluation included biochemical estimation, histology, protein expression as well as apoptosis and DNA damage examinations. Post-treatment with NaB significantly decreased plasma glucose, creatinine, urea, histological alterations including the fibrosis and collagen deposition as well as decreased the HDACs activity, expression of eNOS, iNOS, α-SMA, collagen I, fibronectin, TGFβ-1, NFκB, apoptosis and DNA damage in the diabetic kidney. These results showed that NaB treatment improved the renal function and ameliorated the histological alterations, fibrosis, apoptosis and DNA damage in the kidney of juvenile rats.

  13. The thioacetate-ω(γ-lactam carboxamide) HDAC inhibitor ST7612AA1 as HIV-1 latency reactivation agent.

    PubMed

    Badia, Roger; Grau, Judith; Riveira-Muñoz, Eva; Ballana, Ester; Giannini, Giuseppe; Esté, José A

    2015-11-01

    Antiretroviral therapy (ART) is unable to cure HIV infection. The ability of HIV to establish a subset of latent infected CD4(+) T cells, which remain undetectable to the immune system, becomes a major roadblock to achieve viral eradication. Histone deacetylase inhibitors (HDACi) have been shown to potently induce the reactivation of latent HIV. Here, we show that a new thiol-based HDACi, the thioacetate-ω(γ-lactam carboxamide) derivative ST7612AA1, is a potent inducer of HIV reactivation. We evaluated HIV reactivation activity of ST7612AA1 compared to panobinostat (PNB), romidepsin (RMD) and vorinostat (VOR) in cell culture models of HIV-1 latency, in latently infected primary CD4(+) T lymphocytes and in PBMCs from HIV(+) patients. ST7612AA1 potently induced HIV-1 reactivation at submicromolar concentrations with comparable potency to panobinostat or superior to vorinostat. The presence of known antiretrovirals did not affect ST7612AA1-induced reactivation and their activity was not affected by ST7612AA1. Cell proliferation and cell activation were not affected by ST7612AA1, or any other HDACi used. In conclusion, our results indicate that ST7612AA1 is a potent activator of latent HIV and that reactivation activity of ST7612AA1 is exerted without activation or proliferation of CD4(+) T cells. ST7612AA1 is a suitable candidate for further studies of HIV reactivation strategies and potential new therapies to eradicate the viral reservoirs. PMID:26348004

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Hydrazides of carboxylic acids as inhibitors of steel acidic corrosion

    SciTech Connect

    Aitov, R.G.; Shein, A.B.; Lesnov, A.E.

    1994-09-01

    Hydrazides of carboxylic acids (HCA) inhibit the corrosion of ferrous materials in acids and netral solutions such as stratum and waste waters of oil deposits. In this work, the authors try to explain the above-mentioned difference and to consider HCA as inhibitors of steel hydrogenation.

  20. 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.

  1. The pan-HDAC inhibitor vorinostat potentiates the activity of the proteasome inhibitor carfilzomib in human DLBCL cells in vitro and in vivo.

    PubMed

    Dasmahapatra, Girija; Lembersky, Dmitry; Kramer, Lora; Fisher, Richard I; Friedberg, Jonathan; Dent, Paul; Grant, Steven

    2010-06-01

    Interactions between histone deacetylase inhibitors (HDACIs) and the novel proteasome inhibitor carfilzomib (CFZ) were investigated in GC- and activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) cells. Coadministration of subtoxic or minimally toxic concentrations of CFZ) with marginally lethal concentrations of HDACIs (vorinostat, SNDX-275, or SBHA) synergistically increased mitochondrial injury, caspase activation, and apoptosis in both GC- and ABC-DLBCL cells. These events were associated with Jun NH2-terminal kinase (JNK) and p38MAPK activation, abrogation of HDACI-mediated nuclear factor-kappaB activation, AKT inactivation, Ku70 acetylation, and induction of gammaH2A.X. Genetic or pharmacologic JNK inhibition significantly diminished CFZ/vorinostat lethality. CFZ/vorinostat induced pronounced lethality in 3 primary DLBCL specimens but minimally affected normal CD34(+) hematopoietic cells. Bortezomib-resistant GC (SUDHL16) and ABC (OCI-LY10) cells exhibited partial cross-resistance to CFZ. However, CFZ/vorinostat dramatically induced resistant cell apoptosis, accompanied by increased JNK activation and gammaH2A.X expression. Finally, subeffective vorinostat doses markedly increased CFZ-mediated tumor growth suppression and apoptosis in a murine xenograft OCI-LY10 model. These findings indicate that HDACIs increase CFZ activity in GC- and ABC-DLBCL cells sensitive or resistant to bortezomib through a JNK-dependent mechanism in association with DNA damage and inhibition of nuclear factor-kappaB activation. Together, they support further investigation of strategies combining CFZ and HDACIs in DLBCL. PMID:20233973

  2. The pan-HDAC inhibitor vorinostat potentiates the activity of the proteasome inhibitor carfilzomib in human DLBCL cells in vitro and in vivo

    PubMed Central

    Dasmahapatra, Girija; Lembersky, Dmitry; Kramer, Lora; Fisher, Richard I.; Friedberg, Jonathan; Dent, Paul

    2010-01-01

    Interactions between histone deacetylase inhibitors (HDACIs) and the novel proteasome inhibitor carfilzomib (CFZ) were investigated in GC- and activated B-cell–like diffuse large B-cell lymphoma (ABC-DLBCL) cells. Coadministration of subtoxic or minimally toxic concentrations of CFZ) with marginally lethal concentrations of HDACIs (vorinostat, SNDX-275, or SBHA) synergistically increased mitochondrial injury, caspase activation, and apoptosis in both GC- and ABC-DLBCL cells. These events were associated with Jun NH2-terminal kinase (JNK) and p38MAPK activation, abrogation of HDACI-mediated nuclear factor-κB activation, AKT inactivation, Ku70 acetylation, and induction of γH2A.X. Genetic or pharmacologic JNK inhibition significantly diminished CFZ/vorinostat lethality. CFZ/vorinostat induced pronounced lethality in 3 primary DLBCL specimens but minimally affected normal CD34+ hematopoietic cells. Bortezomib-resistant GC (SUDHL16) and ABC (OCI-LY10) cells exhibited partial cross-resistance to CFZ. However, CFZ/vorinostat dramatically induced resistant cell apoptosis, accompanied by increased JNK activation and γH2A.X expression. Finally, subeffective vorinostat doses markedly increased CFZ-mediated tumor growth suppression and apoptosis in a murine xenograft OCI-LY10 model. These findings indicate that HDACIs increase CFZ activity in GC- and ABC-DLBCL cells sensitive or resistant to bortezomib through a JNK-dependent mechanism in association with DNA damage and inhibition of nuclear factor-κB activation. Together, they support further investigation of strategies combining CFZ and HDACIs in DLBCL. PMID:20233973

  3. 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.

  4. Hdac-Mediated Control of Endochondral and Intramembranous Ossification

    PubMed Central

    Bradley, Elizabeth W.; McGee-Lawrence, Meghan E.; Westendorf, Jennifer J.

    2011-01-01

    Histone deacetylases (Hdacs) remove acetyl groups (CH3CO-) from ε-amino groups in lysine residues within histones and other proteins. This post-translational (de) modification alters protein stability, protein-protein interactions, and chromatin structure. Hdac activity plays important roles in the development of all organs and tissues, including the mineralized skeleton. Bone is a dynamic tissue that forms and regenerates by two processes: endochondral and intramembranous ossification. Chondrocytes and osteoblasts are responsible for producing the extracellular matrices of skeletal tissues. Several Hdacs contribute to the molecular pathways and chromatin changes that regulate tissue-specific gene expression during chondrocyte and osteoblast specification, maturation and terminal differentiation. In this review, we summarize the roles of class I and class II Hdacs in chondrocytes and osteoblasts. The effects of small molecule Hdac inhibitors on the skeleton are also discussed. PMID:22077150

  5. Optimization of a series of potent and selective ketone histone deacetylase inhibitors.

    PubMed

    Pescatore, Giovanna; Kinzel, Olaf; Attenni, Barbara; Cecchetti, Ottavia; Fiore, Fabrizio; Fonsi, Massimiliano; Rowley, Michael; Schultz-Fademrecht, Carsten; Serafini, Sergio; Steinkühler, Christian; Jones, Philip

    2008-10-15

    Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in the clinic. Herein we describe the optimization of a series of ketone small molecule HDAC inhibitors leading to potent and selective class I HDAC inhibitors with good dog PK.

  6. Effects of downregulated HDAC6 expression on the proliferation of lung cancer cells

    SciTech Connect

    Kamemura, Kazuo; Ito, Akihiro Shimazu, Tadahiro; Matsuyama, Akihisa; Maeda, Satoko; Yao, Tso-Pang; Horinouchi, Sueharu; Khochbin, Saadi; Yoshida, Minoru

    2008-09-12

    Histone deacetylase 6 (HDAC6) is a multifunctional, cytosolic protein deacetylase that primarily acts on {alpha}-tubulin. Here we report that stable knockdown of HDAC6 expression causes a decrease in the steady-state level of receptor tyrosine kinases, such as epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor {alpha}, in A549 lung cancer cells. The decreased levels of in EGFR in HDAC6-knockdown cells, which correlated with increased acetylation of microtubules, were due to increased turnover of EGFR protein. Despite the decrease in EGFR levels, A549 cells lacking functional HDAC6 appeared to grow normally, probably due to increased expression of extracellular signal-regulated kinases 1 and 2. Indeed, HDAC6-knockdown cells were more sensitive than control cells to the MEK inhibitor U0126. These results suggest that HDAC6 inhibitors combined with inhibitors of growth factor signaling may be useful as cancer therapy.

  7. 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.

  8. c-Fos Protects Neurons Through a Noncanonical Mechanism Involving HDAC3 Interaction: Identification of a 21-Amino Acid Fragment with Neuroprotective Activity

    PubMed Central

    Rawat, Varun; Goux, Warren; Piechaczyk, Marc

    2016-01-01

    Proteins belonging to the AP-1 family of transcription factors are known to be involved in the regulation of neuronal viability. While strides have been made to elucidate the mechanisms of how individual members regulate cell death, much remains unknown. We find that the expression of one AP-1 member, c-Fos, is reduced in cerebellar granule neurons (CGNs) induced to die by low potassium (LK) treatment. Restoration and increase of this expression protect CGNs against LK-induced death, whereas knockdown induces death of otherwise healthy neurons. Furthermore, forced expression can protect cortical neurons against homocysteic acid (HCA)-induced toxicity. Taken together, this suggests that c-Fos is necessary for neuronal survival and that elevating c-Fos expression has a neuroprotective effect. Consistent with this idea is the finding that c-Fos expression is reduced selectively in the striatum in two separate mouse models of Huntington’s disease and forced expression protects against neuronal death resulting from mutant huntingtin (mut-Htt) expression. Interestingly, neuroprotection by c-Fos does not require its DNA-binding, transcriptional, or heteromerization domains. However, this protective activity can be inhibited by pharmacological inhibition of c-Abl, CK-I, and MEK-ERK signaling. Additionally, expression of point mutant forms of this protein has identified that mutation of a tyrosine residue, Tyr345, can convert c-Fos from neuroprotective to neurotoxic. We show that c-Fos interacts with histone deacetylase-3 (HDAC3), a protein that contributes to mut-Htt neurotoxicity and whose overexpression is sufficient to promote neuronal death. When co-expressed, c-Fos can protect against HDAC3 neurotoxicity. Finally, our study identifies a 21-amino acid region at the C-terminus of c-Fos that is sufficient to protect neurons against death induced by LK, HCA treatment, or mut-Htt expression when expressed via a plasmid transfection or as a cell-permeable peptide. This

  9. 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

  10. 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. PMID:27165113

  11. 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

  12. HDAC6 regulates epidermal growth factor receptor (EGFR) endocytic trafficking and degradation in renal epithelial cells.

    PubMed

    Liu, Wei; Fan, Lucy X; Zhou, Xia; Sweeney, William E; Avner, Ellis D; Li, Xiaogang

    2012-01-01

    We present for the first time that histone deacetylase 6 (HDAC6) regulates EGFR degradation and trafficking along microtubules in Pkd1 mutant renal epithelial cells. HDAC6, the microtubule-associated α-tubulin deacetylase, demonstrates increased expression and activity in Pkd1 mutant mouse embryonic kidney cells. Targeting HDAC6 with a general HDAC inhibitor, trichostatin (TSA), or a specific HDAC6 inhibitor, tubacin, increased the acetylation of α-tubulin and downregulated the expression of EGFR in Pkd1 mutant renal epithelial cells. HDAC6 was co-localized with EGF induced endocytic EGFR and endosomes, respectively. Inhibition of the activity of HDAC6 accelerated the trafficking of EGFR from early endosomes to late endosomes along the microtubules. Without EGF stimulation EGFR was randomly distributed while after stimulation with EGF for 30 min, EGFR was accumulated around α-tubulin labeled microtubule bundles. These data suggested that the Pkd1 mutation induced upregulation of HDAC6 might act to slow the trafficking of EGFR from early endosomes to late endosomes along the microtubules for degradation through deacetylating α-tubulin. In addition, inhibition of HDAC activity decreased the phosphorylation of ERK1/2, the downstream target of EGFR axis, and normalized EGFR localization from apical to basolateral in Pkd1 knockout mouse kidneys. Thus, targeting HDAC6 to downregulate EGFR activity may provide a potential therapeutic approach to treat polycystic kidney disease.

  13. 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

  14. A Potent HDAC Inhibitor, 1-Alaninechlamydocin, from a Tolypocladium sp. Induces G2/M Cell Cycle Arrest and Apoptosis in MIA PaCa-2 Cells

    PubMed Central

    2015-01-01

    The cyclic tetrapeptide 1-alaninechlamydocin was purified from a Great Lakes-derived fungal isolate identified as a Tolypocladium sp. Although the planar structure was previously described, a detailed analysis of its spectroscopic data and biological activity are reported here for the first time. Its absolute configuration was determined using a combination of spectroscopic (1H–1H ROESY, ECD, and X-ray diffraction) and chemical (Marfey’s analysis) methods. 1-Alaninechlamydocin showed potent antiproliferative/cytotoxic activities in a human pancreatic cancer cell line (MIA PaCa-2) at low-nanomolar concentrations (GI50 5.3 nM, TGI 8.8 nM, LC50 22 nM). Further analysis revealed that 1-alaninechlamydocin induced G2/M cell cycle arrest and apoptosis. Similar to other cyclic epoxytetrapeptides, the inhibitory effects of 1-alaninechlamydocin are proposed to be produced primarily via inhibition of histone deacetylase (HDAC) activity. PMID:24999749

  15. Histone deacetylase inhibitors reduce WB-F344 oval cell viability and migration capability by suppressing AKT/mTOR signaling in vitro.

    PubMed

    Zhang, Peng; Zhu, Xiaofeng; Wu, Ying; Hu, Ronglin; Li, Dongming; Du, Jun; Jiao, Xingyuan; He, Xiaoshun

    2016-01-15

    Histone deacetylase (HDAC) can blockDNA replication and transcription and altered HDAC expression was associated with tumorigenesis. This study investigated the effects of HDAC inhibitors on hepatic oval cells and aimed to delineate the underlying molecular events. Hepatic oval cells were treated with two different HDAC inhibitors, suberoylanilidehydroxamic acid (SAHA) and trichostatin-A (TSA). Cells were subjected to cell morphology, cell viability, cell cycle, and wound healing assays. The expression of proteins related to both apoptosis and the cell cycle, and proteins of the AKT/mammalian target of rapamycin (mTOR) signaling pathway were analyzed by Western blot. The data showed that HDAC inhibitors reduced oval cell viability and migration capability, and arrested oval cells at the G0/G1 and S phases of the cell cycle, in a dose- and time-dependent manner. HDAC inhibitors altered cell morphology and reduced oval cell viability, and downregulated the expression of PCNA, cyclinD1, c-Myc and Bmi1 proteins, while also suppressing AKT/mTOR and its downstream target activity. In conclusion, this study demonstrates that HDAC inhibitors affect oval cells by suppressing AKT/mTOR signaling. PMID:26558695

  16. Novel inhibitors of fatty acid amide hydrolase.

    PubMed

    Sit, S Y; Conway, Charlie; Bertekap, Robert; Xie, Kai; Bourin, Clotilde; Burris, Kevin; Deng, Hongfeng

    2007-06-15

    A class of bisarylimidazole derivatives are identified as potent inhibitors of the enzyme fatty acid amide hydrolase (FAAH). Compound 17 (IC(50)=2 nM) dose-dependently (0.1-10mg/kg, iv) potentiates the effects of exogenous anandamide (1 mg/kg, iv) in a rat thermal escape test (Hargreaves test), and shows robust antinociceptive activity in animal models of persistent (formalin test) and neuropathic (Chung model) pain. Compound 17 (20 mg/kg, iv) demonstrates activity in the formalin test that is comparable to morphine (3mg/kg, iv), and is dose-dependently inhibited by the CB1 antagonist SR141716A. In the Chung model, compound 17 shows antineuropathic effects similar to high-dose (100 mg/kg) gabapentin. FAAH inhibition shows potential utility for the clinical treatment of persistent and neuropathic pain.

  17. 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.

  18. 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

  19. 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

  20. Histone deacetylase (HDAC) 10 suppresses cervical cancer metastasis through inhibition of matrix metalloproteinase (MMP) 2 and 9 expression.

    PubMed

    Song, Chenlin; Zhu, Songcheng; Wu, Chuanyue; Kang, Jiuhong

    2013-09-27

    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.

  1. HDAC inhibitors suppress c-Jun/Fra-1-mediated proliferation through transcriptionally downregulating MKK7 and Raf1 in neuroblastoma cells

    PubMed Central

    Tang, Xiaomei; Xia, Yong; He, Guozhen; Min, Zhiqun; Li, Chun; Xiong, Shiqiu; Shi, Zhi; Lu, Yongjian; Yuan, Zhongmin

    2016-01-01

    Activator protein 1 (AP-1) is a transcriptional factor composed of the dimeric members of bZIP proteins, which are frequently deregulated in human cancer cells. In this study, we aimed to identify an oncogenic AP-1 dimer critical for the proliferation of neuroblastoma cells and to investigate whether histone deacetylase inhibitors (HDACIs), a new generation of anticancer agents, could target the AP-1 dimer. We report here that HDACIs including trichostatin A, suberoylanilidehydroxamic acid, valproic acid and M344 can transcriptionally suppress both c-Jun and Fra-1, preceding their inhibition of cell growth. c-Jun preferentially interacting with Fra-1 as a heterodimer is responsible for AP-1 activity and critical for cell growth. Mechanistically, HDACIs suppress Fra-1 expression through transcriptionally downregulating Raf1 and subsequently decreasing MEK1/2-ERK1/2 activity. Unexpectedly, HDACI treatment caused MKK7 downregulation at both the protein and mRNA levels. Deletion analysis of the 5′-flanking sequence of the MKK7 gene revealed that a major element responsible for the downregulation by HDACI is located at −149 to −3 relative to the transcriptional start site. Knockdown of MKK7 but not MKK4 remarkably decreased JNK/c-Jun activity and proliferation, whereas ectopic MKK7-JNK1 reversed HDACI-induced c-Jun suppression. Furthermore, suppression of both MKK-7/c-Jun and Raf-1/Fra-1 activities was involved in the tumor growth inhibitory effects induced by SAHA in SH-SY5Y xenograft mice. Collectively, these findings demonstrated that c-Jun/Fra-1 dimer is critical for neuroblastoma cell growth and that HDACIs act as effective suppressors of the two oncogenes through transcriptionally downregulating MKK7 and Raf1. PMID:26734995

  2. Histone Deacetylase Inhibitor Upregulates Peroxisomal Fatty Acid Oxidation and Inhibits Apoptotic Cell Death in Abcd1-Deficient Glial Cells

    PubMed Central

    Singh, Jaspreet; Khan, Mushfiquddin; Pujol, Aurora; Baarine, Mauhamad; Singh, Inderjit

    2013-01-01

    In X-ALD, mutation/deletion of ALD gene (ABCD1) and the resultant very long chain fatty acid (VLCFA) derangement has dramatically opposing effects in astrocytes and oligodendrocytes. While loss of Abcd1 in astrocytes produces a robust inflammatory response, the oligodendrocytes undergo cell death leading to demyelination in X-linked adrenoleukodystrophy (X-ALD). The mechanisms of these distinct pathways in the two cell types are not well understood. Here, we investigated the effects of Abcd1-knockdown and the subsequent alteration in VLCFA metabolism in human U87 astrocytes and rat B12 oligodendrocytes. Loss of Abcd1 inhibited peroxisomal β-oxidation activity and increased expression of VLCFA synthesizing enzymes, elongase of very long chain fatty acids (ELOVLs) (1 and 3) in both cell types. However, higher induction of ELOVL's in Abcd1-deficient B12 oligodendrocytes than astrocytes suggests that ELOVL pathway may play a prominent role in oligodendrocytes in X-ALD. While astrocytes are able to maintain the cellular homeostasis of anti-apoptotic proteins, Abcd1-deletion in B12 oligodendrocytes downregulated the anti-apototic (Bcl-2 and Bcl-xL) and cell survival (phospho-Erk1/2) proteins, and upregulated the pro-apoptotic proteins (Bad, Bim, Bax and Bid) leading to cell loss. These observations provide insights into different cellular signaling mechanisms in response to Abcd1-deletion in two different cell types of CNS. The apoptotic responses were accompanied by activation of caspase-3 and caspase-9 suggesting the involvement of mitochondrial-caspase-9-dependent mechanism in Abcd1-deficient oligodendrocytes. Treatment with histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) corrected the VLCFA derangement both in vitro and in vivo, and inhibited the oligodendrocytes loss. These observations provide a proof-of principle that HDAC inhibitor SAHA may have a therapeutic potential for X-ALD. PMID:23923017

  3. Disruption of the Class IIa HDAC Corepressor Complex Increases Energy Expenditure and Lipid Oxidation.

    PubMed

    Gaur, Vidhi; Connor, Timothy; Sanigorski, Andrew; Martin, Sheree D; Bruce, Clinton R; Henstridge, Darren C; Bond, Simon T; McEwen, Kevin A; Kerr-Bayles, Lyndal; Ashton, Trent D; Fleming, Cassandra; Wu, Min; Pike Winer, Lisa S; Chen, Denise; Hudson, Gregg M; Schwabe, John W R; Baar, Keith; Febbraio, Mark A; Gregorevic, Paul; Pfeffer, Frederick M; Walder, Ken R; Hargreaves, Mark; McGee, Sean L

    2016-09-13

    Drugs that recapitulate aspects of the exercise adaptive response have the potential to provide better treatment for diseases associated with physical inactivity. We previously observed reduced skeletal muscle class IIa HDAC (histone deacetylase) transcriptional repressive activity during exercise. Here, we find that exercise-like adaptations are induced by skeletal muscle expression of class IIa HDAC mutants that cannot form a corepressor complex. Adaptations include increased metabolic gene expression, mitochondrial capacity, and lipid oxidation. An existing HDAC inhibitor, Scriptaid, had similar phenotypic effects through disruption of the class IIa HDAC corepressor complex. Acute Scriptaid administration to mice increased the expression of metabolic genes, which required an intact class IIa HDAC corepressor complex. Chronic Scriptaid administration increased exercise capacity, whole-body energy expenditure and lipid oxidation, and reduced fasting blood lipids and glucose. Therefore, compounds that disrupt class IIa HDAC function could be used to enhance metabolic health in chronic diseases driven by physical inactivity.

  4. Disruption of the Class IIa HDAC Corepressor Complex Increases Energy Expenditure and Lipid Oxidation.

    PubMed

    Gaur, Vidhi; Connor, Timothy; Sanigorski, Andrew; Martin, Sheree D; Bruce, Clinton R; Henstridge, Darren C; Bond, Simon T; McEwen, Kevin A; Kerr-Bayles, Lyndal; Ashton, Trent D; Fleming, Cassandra; Wu, Min; Pike Winer, Lisa S; Chen, Denise; Hudson, Gregg M; Schwabe, John W R; Baar, Keith; Febbraio, Mark A; Gregorevic, Paul; Pfeffer, Frederick M; Walder, Ken R; Hargreaves, Mark; McGee, Sean L

    2016-09-13

    Drugs that recapitulate aspects of the exercise adaptive response have the potential to provide better treatment for diseases associated with physical inactivity. We previously observed reduced skeletal muscle class IIa HDAC (histone deacetylase) transcriptional repressive activity during exercise. Here, we find that exercise-like adaptations are induced by skeletal muscle expression of class IIa HDAC mutants that cannot form a corepressor complex. Adaptations include increased metabolic gene expression, mitochondrial capacity, and lipid oxidation. An existing HDAC inhibitor, Scriptaid, had similar phenotypic effects through disruption of the class IIa HDAC corepressor complex. Acute Scriptaid administration to mice increased the expression of metabolic genes, which required an intact class IIa HDAC corepressor complex. Chronic Scriptaid administration increased exercise capacity, whole-body energy expenditure and lipid oxidation, and reduced fasting blood lipids and glucose. Therefore, compounds that disrupt class IIa HDAC function could be used to enhance metabolic health in chronic diseases driven by physical inactivity. PMID:27626651

  5. Energy-optimised pharmacophore approach to identify potential hotspots during inhibition of Class II HDAC isoforms.

    PubMed

    Ganai, Shabir Ahmad; Shanmugam, Karthi; Mahadevan, Vijayalakshmi

    2015-01-01

    Histone deacetylases (HDACs) are conjugated enzymes that modulate chromatin architecture by deacetylating lysine residues on the histone tails leading to transcriptional repression. Pharmacological interventions of these enzymes with small molecule inhibitors called Histone deacetylase inhibitors (HDACi) have shown enhanced acetylation of the genome and are hence emerging as potential targets at the clinic. Type-specific inhibition of Class II HDACs has shown enhanced therapeutic benefits against developmental and neurodegenerative disorders. However, the structural identity of class-specific isoforms limits the potential of their inhibitors in precise targeting of their enzymes. Diverse strategies have been implemented to recognise the features in HDAC enzymes which may help in identifying isoform specificity factors. This work attempts a computational approach that combines in silico docking and energy-optimised pharmacophore (E-pharmacophore) mapping of 18 known HDAC inhibitors and has identified structural variations that regulate their interactions against the six Class II HDAC enzymes considered for the study. This combined approach establishes that inhibitors possessing higher number of aromatic rings in different structural regions might function as potent inhibitors, while inhibitors with scarce ring structures might point to compromised potency. This would aid the rationale for chemical optimisation and design of isoform selective HDAC inhibitors with enhanced affinity and therapeutic efficiency.

  6. Non-epigenetic function of HDAC8 in regulating breast cancer stem cells by maintaining Notch1 protein stability

    PubMed Central

    Chao, Min-Wu; Chu, Po-Chen; Chuang, Hsiao-Ching; Shen, Fang-Hsiu; Chou, Chih-Chien; Hsu, En-Chi; Himmel, Lauren E.; Huang, Han-Li; Tu, Huang-Ju; Kulp, Samuel K.; Teng, Che-Ming; Chen, Ching-Shih

    2016-01-01

    Here, we report a novel non-epigenetic function of histone deacetylase (HDAC) 8 in activating cancer stem cell (CSC)-like properties in breast cancer cells by enhancing the stability of Notch1 protein. The pan-HDAC inhibitors AR-42 and SAHA, and the class I HDAC inhibitor depsipeptide, suppressed mammosphere formation and other CSC markers by reducing Notch1 expression in MDA-MB-231 and SUM-159 cells. Interrogation of individual class I isoforms (HDAC1–3 and 8) using si/shRNA-mediated knockdown, ectopic expression and/or pharmacological inhibition revealed HDAC8 to be the primary mediator of this drug effect. This suppression of Notch1 in response to HDAC8 inhibition was abrogated by the proteasome inhibitor MG132 and siRNA-induced silencing of Fbwx7, indicating Notch1 suppression occurred through proteasomal degradation. However, co-immunoprecipitation analysis indicated that HDAC8 did not form complexes with Notch1 and HDAC inhibition had no effect on Notch1 acetylation. In a xenograft tumor model, the tumorigenicity of breast cancer cells was decreased by HDAC8 knockdown. These findings suggest the therapeutic potential of HDAC8 inhibition to suppress Notch1 signaling in breast cancer. PMID:26625202

  7. Non-epigenetic function of HDAC8 in regulating breast cancer stem cells by maintaining Notch1 protein stability.

    PubMed

    Chao, Min-Wu; Chu, Po-Chen; Chuang, Hsiao-Ching; Shen, Fang-Hsiu; Chou, Chih-Chien; Hsu, En-Chi; Himmel, Lauren E; Huang, Han-Li; Tu, Huang-Ju; Kulp, Samuel K; Teng, Che-Ming; Chen, Ching-Shih

    2016-01-12

    Here, we report a novel non-epigenetic function of histone deacetylase (HDAC) 8 in activating cancer stem cell (CSC)-like properties in breast cancer cells by enhancing the stability of Notch1 protein. The pan-HDAC inhibitors AR-42 and SAHA, and the class I HDAC inhibitor depsipeptide, suppressed mammosphere formation and other CSC markers by reducing Notch1 expression in MDA-MB-231 and SUM-159 cells. Interrogation of individual class I isoforms (HDAC1-3 and 8) using si/shRNA-mediated knockdown, ectopic expression and/or pharmacological inhibition revealed HDAC8 to be the primary mediator of this drug effect. This suppression of Notch1 in response to HDAC8 inhibition was abrogated by the proteasome inhibitor MG132 and siRNA-induced silencing of Fbwx7, indicating Notch1 suppression occurred through proteasomal degradation. However, co-immunoprecipitation analysis indicated that HDAC8 did not form complexes with Notch1 and HDAC inhibition had no effect on Notch1 acetylation. In a xenograft tumor model, the tumorigenicity of breast cancer cells was decreased by HDAC8 knockdown. These findings suggest the therapeutic potential of HDAC8 inhibition to suppress Notch1 signaling in breast cancer.

  8. Improved Histone Deacetylase Inhibitors as Therapeutics for the Neurodegenerative Disease Friedreich's Ataxia: A New Synthetic Route

    PubMed Central

    Xu, Chunping; Soragni, Elisabetta; Jacques, Vincent; Rusche, James R.; Gottesfeld, Joel M.

    2011-01-01

    Friedreich's ataxia (FRDA) is caused by transcriptional repression of the nuclear FXN gene encoding the essential mitochondrial protein frataxin. Based on the hypothesis that the acetylation state of the histone proteins is responsible for gene silencing in FRDA, previous work in our lab identified a first generation of HDAC inhibitors (pimelic o-aminobenzamides), which increase FXN mRNA in lymphocytes from FRDA patients. Importantly, these compounds also function in a FRDA mouse model to increase FXN mRNA levels in the brain and heart. While the first generation of HDAC inhibitors hold promise as potential therapeutics for FRDA, they have two potential problems: less than optimal brain penetration and metabolic instability in acidic conditions. Extensive optimization focusing on modifying the left benzene ring, linker and the right benzene ring lead to a novel class of HDAC inhibitors that have optimized pharmacological properties (increased brain penetration and acid stability) compared to the previous HDAC inhibitors. This article will describe the chemical synthesis and pharmacological properties of these new HDAC inhibitors.

  9. A potential adjuvant chemotherapeutics, 18β-glycyrrhetinic acid, inhibits renal tubular epithelial cells apoptosis via enhancing BMP-7 epigenetically through targeting HDAC2

    PubMed Central

    Ma, Taotao; Huang, Cheng; Meng, Xiaoming; Li, Xiaofeng; Zhang, Yilong; Ji, Shuai; Li, Jun; Ye, Min; Liang, Hong

    2016-01-01

    Cisplatin, a highly effective and widely used chemotherapeutic agent, has a major limitation for its nephrotoxicity. We recently identified a novel strategy for attenuating its nephrotoxicity in chemotherapy by an effective adjuvant via epigenetic modification through targeting HDAC2. Molecular docking and SPR assay firstly reported that 18βGA, major metabolite of GA, could directly bind to HDAC2 and inhibit the activity of HDAC2. The effects and mechanisms of GA and 18βGA were assessed in CP-induced AKI in C57BL/6 mice, and in CP-treated HK-2 and mTEC cells lines. TUNEL and FCM results confirmed that GA and 18βGA could inhibit apoptosis of renal tubular epithelial cells induced by CP in vivo and in vitro. Western blot and immunofluorescence results demonstrated that the expression of BMP-7 was clearly induced by 18βGA in AKI models while siRNA BMP-7 could reduce the inhibitory effect of 18βGA on apoptosis. Results of current study indicated that 18βGA inhibited apoptosis of renal tubular epithelial cells via enhancing the level of BMP-7 epigenetically through targeting HDAC2, therefore protecting against CP-induced AKI. These available evidence, which led to an improved understanding of molecular recognition, suggested that 18βGA could serve as a potential clinical adjuvant in chemotherapy. PMID:27145860

  10. 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

  11. A dual role for Hdac1: oncosuppressor in tumorigenesis, oncogene in tumor maintenance.

    PubMed

    Santoro, Fabio; Botrugno, Oronza A; Dal Zuffo, Roberto; Pallavicini, Isabella; Matthews, Geoffrey M; Cluse, Leonie; Barozzi, Iros; Senese, Silvia; Fornasari, Lorenzo; Moretti, Simona; Altucci, Lucia; Pelicci, Pier Giuseppe; Chiocca, Susanna; Johnstone, Ricky W; Minucci, Saverio

    2013-04-25

    Aberrant recruitment of histone deacetylases (HDACs) by the oncogenic fusion protein PML-RAR is involved in the pathogenesis of acute promyelocytic leukemia (APL). PML-RAR, however, is not sufficient to induce disease in mice but requires additional oncogenic lesions during the preleukemic phase. Here, we show that knock-down of Hdac1 and Hdac2 dramatically accelerates leukemogenesis in transgenic preleukemic mice. These events are not restricted to APL because lymphomagenesis driven by deletion of p53 or, to a lesser extent, by c-myc overexpression, was also accelerated by Hdac1 knock-down. In the preleukemic phase of APL, Hdac1 counteracts the activity of PML-RAR in (1) blocking differentiation; (2) impairing genomic stability; and (3) increasing self-renewal in hematopoietic progenitors, as all of these events are affected by the reduction in Hdac1 levels. This led to an expansion of a subpopulation of PML-RAR-expressing cells that is the major source of leukemic stem cells in the full leukemic stage. Remarkably, short-term treatment of preleukemic mice with an HDAC inhibitor accelerated leukemogenesis. In contrast, knock-down of Hdac1 in APL mice led to enhanced survival duration of the leukemic animals. Thus, Hdac1 has a dual role in tumorigenesis: oncosuppressive in the early stages, and oncogenic in established tumor cells.

  12. Class I HDACs regulate angiotensin II-dependent cardiac fibrosis via fibroblasts and circulating fibrocytes.

    PubMed

    Williams, Sarah M; Golden-Mason, Lucy; Ferguson, Bradley S; Schuetze, Katherine B; Cavasin, Maria A; Demos-Davies, Kim; Yeager, Michael E; Stenmark, Kurt R; McKinsey, Timothy A

    2014-02-01

    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.

  13. 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

    2016-01-01

    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.

  14. Sumoylation of HDAC2 promotes NF-κB-dependent gene expression.

    PubMed

    Wagner, Tobias; Kiweler, Nicole; Wolff, Katharina; Knauer, Shirley K; Brandl, André; Hemmerich, Peter; Dannenberg, Jan-Hermen; Heinzel, Thorsten; Schneider, Günter; Krämer, Oliver H

    2015-03-30

    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. 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

  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 valproic acid and depsipeptide sensitize retinoblastoma cells to radiotherapy by increasing H2AX phosphorylation and p53 acetylation-phosphorylation.

    PubMed

    Kawano, Takeshi; Akiyama, Masaharu; Agawa-Ohta, Miyuki; Mikami-Terao, Yoko; Iwase, Satsuki; Yanagisawa, Takaaki; Ida, Hiroyuki; Agata, Naoki; Yamada, Hisashi

    2010-10-01

    Although p53 is intact in most cases of retinoblastoma, it is largely inactivated by the ubiqutin-proteasome system through interaction with murine double minute 2 (MDM2) and murine double minute X (MDMX). The present study showed that the histone deacetylase (HDAC) inhibitors valproic acid (VPA) and depsipeptide (FK228) synergistically enhanced ionizing radiation (IR)-induced apoptosis, associated with activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase in Y79 and WER1-Rb1 human retinoblastoma cells. Both VPA and FK228 enhanced IR-induced phosphorylation of histone H2AX on Ser139 preceding apoptosis. Exposure of cells to IR in the presence of VPA or FK228 induced the accumulation of p53 acetylated at Lys382 and phosphorylated at Ser46 through the reduction of binding affinity with MDM2 and MDMX. These results suggest that acetylation of p53 by HDAC inhibitors is a promising new therapeutic target in refractory retinoblastoma. PMID:20811699

  18. 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.

  19. The HDAC inhibitor Givinostat modulates the hematopoietic transcription factors NFE2 and C-MYB in JAK2(V617F) myeloproliferative neoplasm cells.

    PubMed

    Amaru Calzada, Ariel; Todoerti, Katia; Donadoni, Luca; Pellicioli, Anna; Tuana, Giacomo; Gatta, Raffaella; Neri, Antonino; Finazzi, Guido; Mantovani, Roberto; Rambaldi, Alessandro; Introna, Martino; Lombardi, Luigia; Golay, Josée

    2012-08-01

    We investigated the mechanism of action of the histone deacetylase inhibitor Givinostat (GVS) in Janus kinase 2 (JAK2)(V617F) myeloproliferative neoplasm (MPN) cells. GVS inhibited colony formation and proliferation and induced apoptosis at doses two- to threefold lower in a panel of JAK2(V617F) MPN compared to JAK2 wild-type myeloid leukemia cell lines. By global gene expression analysis, we observed that at 6 hours, GVS modulated 293 common genes in the JAK2(V617F) cell lines HEL and UKE1, of which 19 are implicated in cell cycle regulation and 33 in hematopoiesis. In particular, the hematopoietic transcription factors NFE2 and C-MYB were downmodulated by the drug specifically in JAK2(V617F) cells at both the RNA and protein level. GVS also inhibited JAK2-signal transducer and activator of transcription 5-extracellular signal-regulated kinase 1/2 phosphorylation, but modulation of NFE2 and C-MYB was JAK2-independent, as shown using the JAK2 inhibitor TG101209. GVS had a direct effect on the NFE2 promoters, as demonstrated by specific enrichment of associated histone H3 acetylated at lysine 9. Modulation by GVS of NFE2 was also observed in freshly isolated CD34(+) cells from MPN patients, and was accompanied by inhibition of their proliferation and differentiation toward the erythroid lineage. We conclude that GVS acts on MPN cells through dual JAK2-signal transducer and activator of transcription 5-extracellular signal-regulated kinase 1/2 inhibition and downmodulation of NFE2 and C-MYB transcription. PMID:22579713

  20. 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

  1. Disruption of IkappaB kinase (IKK)-mediated RelA serine 536 phosphorylation sensitizes human multiple myeloma cells to histone deacetylase (HDAC) inhibitors.

    PubMed

    Dai, Yun; Chen, Shuang; Wang, Li; Pei, Xin-Yan; Funk, Vanessa L; Kramer, Lora B; Dent, Paul; Grant, Steven

    2011-09-30

    Post-translational modifications of RelA play an important role in regulation of NF-κB activation. We previously demonstrated that in malignant hematopoietic cells, histone deacetylase inhibitors (HDACIs) induced RelA hyperacetylation and NF-κB activation, attenuating lethality. We now present evidence that IκB kinase (IKK) β-mediated RelA Ser-536 phosphorylation plays a significant functional role in promoting RelA acetylation, inducing NF-κB activation, and limiting HDACI lethality in human multiple myeloma (MM) cells. Immunoblot profiling revealed that although basal RelA phosphorylation varied in MM cells, Ser-536 phosphorylation correlated with IKK activity. Exposure to the pan-HDACIs vorinostat or LBH-589 induced phosphorylation of IKKα/β (Ser-180/Ser-181) and RelA (Ser-536) in MM cells, including cells expressing an IκBα "super-repressor," accompanied by increased RelA nuclear translocation, acetylation, DNA binding, and transactivation activity. These events were substantially blocked by either pan-IKK or IKKβ-selective inhibitors, resulting in marked apoptosis. Consistent with these events, inhibitory peptides targeting either the NF-κB essential modulator (NEMO) binding domain for IKK complex formation or RelA phosphorylation sites also significantly increased HDACI lethality. Moreover, IKKβ knockdown by shRNA prevented Ser-536 phosphorylation and significantly enhanced HDACI susceptibility. Finally, introduction of a nonphosphorylatable RelA mutant S536A, which failed to undergo acetylation in response to HDACIs, impaired NF-κB activation and increased cell death. These findings indicate that HDACIs induce Ser-536 phosphorylation of the NF-κB subunit RelA through an IKKβ-dependent mechanism, an action that is functionally involved in activation of the cytoprotective NF-κB signaling cascade primarily through facilitation of RelA acetylation rather than nuclear translocation. PMID:21816815

  2. 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

  3. 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.

  4. Converting maslinic acid into an effective inhibitor of acylcholinesterases.

    PubMed

    Schwarz, Stefan; Loesche, Anne; Lucas, Susana Dias; Sommerwerk, Sven; Serbian, Immo; Siewert, Bianka; Pianowski, Elke; Csuk, René

    2015-10-20

    During the last decade, maslinic acid has been evaluated for many biological properties, e.g. as an anti-tumor or an anti-viral agent but also as a nutraceutical. The potential of maslinic acid and related derivatives to act as inhibitors of acetyl- or butyryl-cholinesterase was examined in this communication in more detail. Cholinesterases do still represent an interesting group of target enzymes with respect to the investigation and treatment of the Alzheimer's disease and other dementia illnesses as well. Although other triterpenoic acids have successfully been tested for their ability to act as inhibitors of cholinesterases, up to now maslinic acid has not been part of such studies. For this reason, three series of maslinic acid derivatives possessing modifications at different centers were synthesized and subjected to Ellman's assay to determine their inhibitory strength and type of inhibitory action. While parent compound maslinic acid was no inhibitor in these assays, some of the compounds exhibited an inhibition of acetylcholinesterase in the single-digit micro-molar range. Two compounds were identified as inhibitors of butyrylcholinesterase showing inhibition constants comparable to those of galantamine, a drug often used in the treatment of Alzheimer's disease. Furthermore, additional selectivity as well as cytotoxicity studies were performed underlining the potential of several derivatives and qualifying them for further investigations. Docking studies revealed that the different kinetic behavior within the same compound series may be explained by the ability of the compounds to enter the active site gorge of AChE. PMID:26383128

  5. 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.

  6. 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

  7. Novel histone deacetylase inhibitors in clinical trials as anti-cancer agents

    PubMed Central

    2010-01-01

    Histone deacetylases (HDACs) can regulate expression of tumor suppressor genes and activities of transcriptional factors involved in both cancer initiation and progression through alteration of either DNA or the structural components of chromatin. Recently, the role of gene repression through modulation such as acetylation in cancer patients has been clinically validated with several inhibitors of HDACs. One of the HDAC inhibitors, vorinostat, has been approved by FDA for treating cutaneous T-cell lymphoma (CTCL) for patients with progressive, persistent, or recurrent disease on or following two systemic therapies. Other inhibitors, for example, FK228, PXD101, PCI-24781, ITF2357, MGCD0103, MS-275, valproic acid and LBH589 have also demonstrated therapeutic potential as monotherapy or combination with other anti-tumor drugs in CTCL and other malignancies. At least 80 clinical trials are underway, testing more than eleven different HDAC inhibitory agents including both hematological and solid malignancies. This review focuses on recent development in clinical trials testing HDAC inhibitors as anti-tumor agents. PMID:20132536

  8. Discovery of 1-hydroxypyridine-2-thiones as selective histone deacetylase inhibitors and their potential application for treating leukemia.

    PubMed

    Muthyala, Ramaiah; Shin, Woo Shik; Xie, Jiashu; Sham, Yuk Yin

    2015-10-01

    Histone deacetylase (HDAC) is a validated target for pursuing anticancer agents. However, obtaining a selective inhibitor against a given HDAC member remains a significant challenge. We report here the use of 1-hydroxypyridine-2-thione (1HPT) as a key pharmacophore for zinc-binding can result in highly selective HDAC inhibitors. 1HPT-6-carboxylic acid exhibits selective inhibition of HDAC6 with an IC50 of 150 nM that corresponds to a remarkable 0.9 ligand efficiency. Two analogs with simple amino acids shows nearly 600-fold selectivity among the eleven zinc-dependent HDACs. At low micromolar concentration these compounds inhibit the growth of HDAC8-overexpressing chronic myelogenous leukemia cells and specific form of acute myelogenous leukemia cells. Their potential mode of binding was examined by molecular docking and their stability was assessed in mouse and human plasma. Together the results suggest 1HPT analogs exhibit promising therapeutic potential for further development as anticancer agents to treat leukemia. PMID:26264503

  9. Overexpressed HDAC4 is associated with poor survival and promotes tumor progression in esophageal carcinoma

    PubMed Central

    Mai, Shi-Juan; Wang, Meng-He; Zhang, Mei-Yin; Zheng, X.F. Steven; Wang, Hui-Yun

    2016-01-01

    Histone deacetylases (HDACs) mediate histone deacetylation, leading to transcriptional repression, which is involved in many diseases, including age-related tissue degeneration, heart failure and cancer. In this study, we were aimed to investigate the expression, clinical significance and biological function of HDAC4 in esophageal carcinoma (EC). We found that HDAC4 mRNA and protein are overexpressed in esophageal squamous cell carcinoma (ESCC) tissues and cell lines. HDAC4 overexpression is associated with higher tumor grade, advanced clinical stage and poor survival. Mechanistically, HDAC4 promotes proliferation and G1/S cell cycle progression in EC cells by inhibiting cyclin-dependent kinase (CDK) inhibitors p21 and p27 and up-regulating CDK2/4 and CDK-dependent Rb phosphorylation. HDAC4 also enhances ESCC cell migration. Furthermore, HDAC4 positively regulates epithelial-mesenchymal transition (EMT) by increasing the expression of Vimentin and decreasing the expression of E-Cadherin/α-Catenin. Together, our study shows that HDAC4 overexpression is important for the oncogenesis of EC, which may serve as a useful prognostic biomarker and therapeutic target for this malignancy. PMID:27295551

  10. HDAC2 deregulation in tumorigenesis is causally connected to repression of immune modulation and defense escape.

    PubMed

    Conte, Mariarosaria; Dell'Aversana, Carmela; Benedetti, Rosaria; Petraglia, Francesca; Carissimo, Annamaria; Petrizzi, Valeria Belsito; D'Arco, Alfonso Maria; Abbondanza, Ciro; Nebbioso, Angela; Altucci, Lucia

    2015-01-20

    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

  11. 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.

  12. Inhibition of HDAC3- and HDAC6-Promoted Survivin Expression Plays an Important Role in SAHA-Induced Autophagy and Viability Reduction in Breast Cancer Cells

    PubMed Central

    Lee, Jane Ying-Chieh; Kuo, Ching-Wen; Tsai, Shing-Ling; Cheng, Siao Muk; Chen, Shang-Hung; Chan, Hsiu-Han; Lin, Chun-Hui; Lin, Kun-Yuan; Li, Chien-Feng; Kanwar, Jagat R.; Leung, Euphemia Y.; Cheung, Carlos Chun Ho; Huang, Wei-Jan; Wang, Yi-Ching; Cheung, Chun Hei Antonio

    2016-01-01

    SAHA is a class I HDAC/HDAC6 co-inhibitor and an autophagy inducer currently undergoing clinical investigations in breast cancer patients. However, the molecular mechanism of action of SAHA in breast cancer cells remains unclear. In this study, we found that SAHA is equally effective in targeting cells of different breast cancer subtypes and tamoxifen sensitivity. Importantly, we found that down-regulation of survivin plays an important role in SAHA-induced autophagy and cell viability reduction in human breast cancer cells. SAHA decreased survivin and XIAP gene transcription, induced survivin protein acetylation and early nuclear translocation in MCF7 and MDA-MB-231 breast cancer cells. It also reduced survivin and XIAP protein stability in part through modulating the expression and activation of the 26S proteasome and heat-shock protein 90. Interestingly, targeting HDAC3 and HDAC6, but not other HDAC isoforms, by siRNA/pharmacological inhibitors mimicked the effects of SAHA in modulating the acetylation, expression, and nuclear translocation of survivin and induced autophagy in MCF7 and MDA-MB-231 cancer cells. Targeting HDAC3 also mimicked the effect of SAHA in up-regulating the expression and activity of proteasome, which might lead to the reduced protein stability of survivin in breast cancer cells. In conclusion, this study provides new insights into SAHA's molecular mechanism of actions in breast cancer cells. Our findings emphasize the complexity of the regulatory roles in different HDAC isoforms and potentially assist in predicting the mechanism of novel HDAC inhibitors in targeted or combinational therapies in the future. PMID:27065869

  13. Histone deacetylase inhibitors stimulate the susceptibility of A549 cells to a plasma-activated medium treatment.

    PubMed

    Adachi, Tetsuo; Kano, Ayame; Nonomura, Saho; Kamiya, Tetsuro; Hara, Hirokazu

    2016-09-15

    The number of potential applications of non-thermal atmospheric pressure plasma (NTAPP) discharges in medicine, particularly in cancer therapy, has increased in recent years. NTAPP has been shown to affect cells not only by direct irradiation, but also by an indirect treatment with previously prepared plasma-activated medium (PAM). Histone deacetylase (HDAC) inhibitors have the potential to enhance susceptibility to anticancer drugs and radiation. The aim of the present study was to demonstrate the advantage of the combined application of PAM and HDAC inhibitors on A549 cancer cell survival and elucidate the underlying mechanisms. Cell death with DNA breaks in the nucleus was greater using combined regimens of PAM and HDAC inhibitors such as trichostatin A (TSA) and valproic acid (VPA) than a single PAM treatment and was accompanied by the activation of poly (ADP-ribose) polymerase-1 (PARP-1), depletion of ATP, and elevations in intracellular calcium levels. Moreover, the expression of Rad 51, a DNA repair factor in homologous recombination pathways, was significantly suppressed by the treatment with HDAC inhibitors. These results demonstrate that HDAC inhibitors may synergistically induce the sensitivity of cancer cells to PAM components. PMID:27470189

  14. 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

  15. Requirement of HDAC6 for activation of Notch1 by TGF-β1

    PubMed Central

    Deskin, Brian; Lasky, Joseph; Zhuang, Yan; Shan, Bin

    2016-01-01

    TGF-β1 is enriched in the tumor microenvironment and acts as a key inducer of epithelial to mesenchymal transition (EMT) in lung cancer. The NOTCH signaling pathway is conserved across species and is an essential pathway for development, cell differentiation, and cancer biology. Dysregulation of Notch signaling is a common feature of non-small cell lung cancer (NSCLC) and is correlated with poor prognosis. Crosstalk exists between the NOTCH and TGF-β signaling pathways in EMT. Herein we report that histone deacetylase 6 (HDAC6) modulates TGF-β1-mediated activation of the Notch pathway. HDAC6, a primarily cytoplasmic deacetylase, mediates TGF-β1-induced EMT in human lung cancer cells. Inhibition of HDAC6 with a small molecule inhibitor, namely tubacin or with siRNA attenuated TGF-β1-induced Notch-1 signaling. We show that TGFβ-1-induced EMT is accompanied by rapid HDAC6-dependent deacetylation of heat shock protein 90 (HSP90). Consistently, inhibition of HSP90 with its small molecule inhibitor 17AAG attenuated expression of TGF-β1-induced Notch-1 target genes, HEY-1 and HES-1. These findings reveal a novel function of HDAC6 in EMT via mediating the TGF-β-Notch signaling cascade, and support HDAC6 as a key regulator of TGFβ-induced EMT in NSCLC. This work suggests that HDAC6 may be an attractive therapeutic target against tumor progression and metastasis. PMID:27499032

  16. 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.

  17. 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.

  18. Structural insights into HDAC6 tubulin deacetylation and its selective inhibition.

    PubMed

    Miyake, Yasuyuki; Keusch, Jeremy J; Wang, Longlong; Saito, Makoto; Hess, Daniel; Wang, Xiaoning; Melancon, Bruce J; Helquist, Paul; Gut, Heinz; Matthias, Patrick

    2016-09-01

    We report crystal structures of zebrafish histone deacetylase 6 (HDAC6) catalytic domains in tandem or as single domains in complex with the (R) and (S) enantiomers of trichostatin A (TSA) or with the HDAC6-specific inhibitor nexturastat A. The tandem domains formed, together with the inter-domain linker, an ellipsoid-shaped complex with pseudo-twofold symmetry. We identified important active site differences between both catalytic domains and revealed the binding mode of HDAC6 selective inhibitors. HDAC inhibition assays with (R)- and (S)-TSA showed that (R)-TSA was a broad-range inhibitor, whereas (S)-TSA had moderate selectivity for HDAC6. We identified a uniquely positioned α-helix and a flexible tryptophan residue in the loop joining α-helices H20 to H21 as critical for deacetylation of the physiologic substrate tubulin. Using single-molecule measurements and biochemical assays we demonstrated that HDAC6 catalytic domain 2 deacetylated α-tubulin lysine 40 in the lumen of microtubules, but that its preferred substrate was unpolymerized tubulin. PMID:27454931

  19. Valproic Acid Prevents Penile Fibrosis and Erectile Dysfunction in Cavernous Nerve Injured Rats

    PubMed Central

    Hannan, Johanna L.; Kutlu, Omer; Stopak, Bernard L.; Liu, Xiaopu; Castiglione, Fabio; Hedlund, Petter; Burnett, Arthur L.; Bivalacqua, Trinity J.

    2014-01-01

    Introduction 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. Aims 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. Methods Five groups of rats (8–10 wks, n=10/group) were utilized: 1) sham, 2&3) BCNI 14 and 30 days following injury, and 4&5) BCNI treated with HDAC inhibitor valproic acid (VPA 250mg/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. Main Outcome Measures ICP; HDAC3, HDAC4, fibronectin and TGF-β1 protein expression; penile fibrosis; penile α-SMA content. Results 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). Conclusion HDAC-induced pathological signaling in response to BCNI contributes to penile vascular dysfunction after BCNI. Pharmacological inhibition of HDAC prevents penile fibrosis, normalizes fibronectin

  20. 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

  1. Design and synthesis of boronic acid inhibitors of endothelial lipase.

    PubMed

    O'Connell, Daniel P; LeBlanc, Daniel F; Cromley, Debra; Billheimer, Jeffrey; Rader, Daniel J; Bachovchin, William W

    2012-02-01

    Endothelial lipase (EL) and lipoprotein lipase (LPL) are homologous lipases that act on plasma lipoproteins. EL is predominantly a phospholipase and appears to be a key regulator of plasma HDL-C. LPL is mainly a triglyceride lipase regulating (V)LDL levels. The existing biological data indicate that inhibitors selective for EL over LPL should have anti-atherogenic activity, mainly through increasing plasma HDL-C levels. We report here the synthesis of alkyl, aryl, or acyl-substituted phenylboronic acids that inhibit EL. Many of the inhibitors evaluated proved to be nearly equally potent against both EL and LPL, but several exhibited moderate to good selectivity for EL. PMID:22225633

  2. The role of butyrate, a histone deacetylase inhibitor in diabetes mellitus: experimental evidence for therapeutic intervention.

    PubMed

    Khan, Sabbir; Jena, Gopabandhu

    2015-01-01

    The contribution of epigenetic mechanisms in diabetes mellitus (DM), β-cell reprogramming and its complications is an emerging concept. Recent evidence suggests that there is a link between DM and histone deacetylases (HDACs), because HDAC inhibitors promote β-cell differentiation, proliferation, function and improve insulin resistance. Moreover, gut microbes and diet-derived products can alter the host epigenome. Furthermore, butyrate and butyrate-producing microbes are decreased in DM. Butyrate is a short-chain fatty acid produced from the fermentation of dietary fibers by microbiota and has been proven as an HDAC inhibitor. The present review provides a pragmatic interpretation of chromatin-dependent and independent complex signaling/mechanisms of butyrate for the treatment of Type 1 and Type 2 DM, with an emphasis on the promising strategies for its drugability and therapeutic implication.

  3. 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.

  4. Investigating the Selectivity of Metalloenzyme Inhibitors

    PubMed Central

    Day, Joshua A.; Cohen, Seth M.

    2013-01-01

    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 Fe3+ from holo-transferrin to gauge the ability of the inhibitors to access Fe3+ 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. PMID:24074025

  5. Identification of an epigenetic signature of early mouse liver regeneration that is disrupted by Zn-HDAC inhibition.

    PubMed

    Huang, Jiansheng; Schriefer, Andrew E; Yang, Wei; Cliften, Paul F; Rudnick, David A

    2014-11-01

    Liver regeneration has been well studied with hope of discovering strategies to improve liver disease outcomes. Nevertheless, the signals that initiate such regeneration remain incompletely defined, and translation of mechanism-based pro-regenerative interventions into new treatments for hepatic diseases has not yet been achieved. We previously reported the isoform-specific regulation and essential function of zinc-dependent histone deacetylases (Zn-HDACs) during mouse liver regeneration. Those data suggest that epigenetically regulated anti-proliferative genes are deacetylated and transcriptionally suppressed by Zn-HDAC activity or that pro-regenerative factors are acetylated and induced by such activity in response to partial hepatectomy (PH). To investigate these possibilities, we conducted genome-wide interrogation of the liver histone acetylome during early PH-induced liver regeneration in mice using acetyL-histone chromatin immunoprecipitation and next generation DNA sequencing. We also compared the findings of that study to those seen during the impaired regenerative response that occurs with Zn-HDAC inhibition. The results reveal an epigenetic signature of early liver regeneration that includes both hyperacetylation of pro-regenerative factors and deacetylation of anti-proliferative and pro-apoptotic genes. Our data also show that administration of an anti-regenerative regimen of the Zn-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) not only disrupts gene-specific pro-regenerative changes in liver histone deacetylation but also reverses PH-induced effects on histone hyperacetylation. Taken together, these studies offer new insight into and suggest novel hypotheses about the epigenetic mechanisms that regulate liver regeneration.

  6. 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.

  7. 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. PMID:27436582

  8. 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

  9. AR-42 induces apoptosis in human hepatocellular carcinoma cells via HDAC5 inhibition

    PubMed Central

    Zhang, Mingming; Pan, Yida; Dorfman, Robert G.; Chen, Zhaogui; Liu, Fuchen; Zhou, Qian; Huang, Shan; Zhang, Jun; Yang, Dongqin; Liu, Jie

    2016-01-01

    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. PMID:26993777

  10. 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.

  11. 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

  12. Salicylic Acid Inhibits Synthesis of Proteinase Inhibitors in Tomato Leaves Induced by Systemin and Jasmonic Acid.

    PubMed Central

    Doares, S. H.; Narvaez-Vasquez, J.; Conconi, A.; Ryan, C. A.

    1995-01-01

    Salicylic acid (SA) and acetylsalicylic acid (ASA), previously shown to inhibit proteinase inhibitor synthesis induced by wounding, oligouronides (H.M. Doherty, R.R. Selvendran, D.J. Bowles [1988] Physiol Mol Plant Pathol 33: 377-384), and linolenic acid (H. Pena-Cortes, T. Albrecht, S. Prat, E.W. Weiler, L. Willmitzer [1993] Planta 191: 123-128), are shown here to be potent inhibitors of systemin-induced and jasmonic acid (JA)-induced synthesis of proteinase inhibitor mRNAs and proteins. The inhibition by SA and ASA of proteinase inhibitor synthesis induced by systemin and JA, as well as by wounding and oligosaccharide elicitors, provides further evidence that both oligosaccharide and polypeptide inducer molecules utilize the octadecanoid pathway to signal the activation of proteinase inhibitor genes. Tomato (Lycopersicon esculentum) leaves were pulse labeled with [35S]methionine, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the inhibitory effects of SA are shown to be specific for the synthesis of a small number of JA-inducible proteins that includes the proteinase inhibitors. Previous results have shown that SA inhibits the conversion of 13S-hydroperoxy linolenic acid to 12-oxo-phytodienoic acid, thereby inhibiting the signaling pathway by blocking synthesis of JA. Here we report that the inhibition of synthesis of proteinase inhibitor proteins and mRNAs by SA in both light and darkness also occurs at a step in the signal transduction pathway, after JA synthesis but preceding transcription of the inhibitor genes. PMID:12228577

  13. Histone deacetylase inhibitors enhance phosphorylation of histone H2AX after ionizing radiation

    SciTech Connect

    Zhang Yubin; Adachi, Masaaki . E-mail: adachi@sapmed.ac.jp; Zou Huichao; Hareyama, Masato; Imai, Kohzoh; Shinomura, Yasuhisa

    2006-07-01

    Purpose Histone deacetylase (HDAC) inhibitors are believed to be promising radiosensitizers. To explore their effects on ionizing radiation (IR), we examined whether the HDAC inhibitors m-carboxycinnamic acid bis-hydroxamide (CBHA) and depsipeptide FK228 affect H2AX phosphorylation ({gamma}-H2AX), a landmark of DNA double-strand breaks after IR exposure. Methods and Materials We evaluated the effects of the HDAC inhibitors on clonogenic assay in human lung carcinoma A549 cells and progression of A549 xenograft tumors. IR-induced DNA damage was evaluated by histone {gamma}-H2AX. Histone hyperacetylation was induced by overexpression of histone acetyltransferase p300 and evaluated by Western blots. Results M-carboxycinnamic acid bishydroxyamide pretreatment radiosensitized A549 cells and strongly inhibited A549 xenograft tumor progression. CBHA and FK228, but not 5-fluorouracil, enhanced IR-induced {gamma}-H2AX in A549 and other cancer cell lines. Overexpression of p300 similarly augmented IR-induced {gamma}-H2AX. Conclusion The results of this study suggest that HDAC inhibitors enhance IR-induced {gamma}-H2AX, most likely through histone hyperacetylation, and radiosensitize various cancers.

  14. 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.

  15. Bisphosphonic acids as effective inhibitors of Mycobacterium tuberculosis glutamine synthetase.

    PubMed

    Kosikowska, Paulina; Bochno, Marta; Macegoniuk, Katarzyna; Forlani, Giuseppe; Kafarski, Paweł; Berlicki, Łukasz

    2016-12-01

    Inhibition of glutamine synthetase (GS) is one of the most promising strategies for the discovery of novel drugs against tuberculosis. Forty-three bisphosphonic and bis-H-phosphinic acids of various scaffolds, bearing aromatic substituents, were screened against recombinant GS from Mycobacterium tuberculosis. Most of the studied compounds exhibited activities in micromolar range, with N-(3,5-dichlorophenyl)-2-aminoethylidenebisphoshonic acid, N-(3,5-difluorophenyl)-2-aminoethylidene-bisphoshonic acid and N-(3,4-dichlorophenyl)-1-hydroxy-1,1-ethanebisphosphonic acid showing the highest potency with kinetic parameters similar to the reference compound - L-methionine-S-sulfoximine. Moreover, these inhibitors were found to be much more effective against pathogen enzyme than against the human ortholog. Thus, with the bone-targeting properties of the bisphosphonate compounds in mind, this activity/selectivity profile makes these compounds attractive agents for the treatment of bone tuberculosis.

  16. 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.

  17. 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

  18. LTR12 promoter activation in a broad range of human tumor cells by HDAC inhibition

    PubMed Central

    Krönung, Sonja K.; Beyer, Ulrike; Chiaramonte, Maria Luisa; Dolfini, Diletta; Mantovani, Roberto; Dobbelstein, Matthias

    2016-01-01

    A considerable proportion of the human genome consists of transposable elements, including the long terminal repeats (LTRs) of endogenous retroviruses. During evolution, such LTRs were occasionally inserted upstream of protein-coding genes, contributing to their regulation. We previously identified the LTR12 from endogenous retrovirus 9 (ERV9) as a regulator of proapoptotic genes such as TP63 or TNFRSF10B. The promoter activity of LTR12 is largely confined to the testes, silenced in testicular carcinoma, but reactivated in testicular cancer cells by broad-range histone deacetylase (HDAC) inhibitors. Here we show that inhibition of HDAC1-3 is sufficient for LTR12 activation. Importantly, HDAC inhibitors induce LTR12 activity not only in testicular cancer cells, but also in cells derived from many additional tumor species. Finally, we characterize the transcription factor NF-Y as a mediator of LTR12 promoter activity and HDAC inhibitor-induced apoptosis, in the context of widespread genomic binding of NF-Y to specific LTR12 sequences. Thus, HDAC inhibitor-driven LTR12 activation represents a generally applicable means to induce proapoptotic genes in human cancer cells. PMID:27172897

  19. 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. PMID:26691930

  20. Transcriptional induction of GRP78/BiP by histone deacetylase inhibitors and resistance to histone deacetylase inhibitor-induced apoptosis

    PubMed Central

    Baumeister, Peter; Dong, Dezheng; Fu, Yong; Lee, Amy S.

    2009-01-01

    Histone deacetylase (HDAC) inhibitors are emerging as effective therapies in the treatment of cancer, and the role of HDACs in the regulation of promoters is rapidly expanding. GRP78/BiP is a stress inducible endoplasmic reticulum (ER) chaperone with anti-apoptotic properties. We present here the mechanism for repression of the Grp78 promoter by histone deacetylase 1 (HDAC1). Our studies reveal that HDAC inhibitors specifically induce GRP78, and the induction level is amplified by ER stress. Through mutational analysis, we have identified the minimal Grp78 promoter and specific elements responsible for HDAC-mediated repression. We show the involvement of HDAC1 in the negative regulation of the Grp78 promoter not only by its induction in the presence of the HDAC inhibitors trichostatin A and MS-275, but also by exogenous overexpression and siRNA knockdown of specific HDACs. We present the results of chromatin immunoprecipitation analysis that reveals the binding of HDAC1 to the Grp78 promoter before but not after ER stress. Furthermore, overexpression of GRP78 confers resistance to HDAC inhibitor induced apoptosis in cancer cells and, conversely, suppression of GRP78 sensitizes them to HDAC inhibitor. These results define HDAC inhibitors as new agents that upregulate GRP78 without concomitantly inducing the ER or heat shock stress response, and suppression of GRP78 in tumors may provide a novel, adjunctive option to enhance anti-cancer therapies that utilize these compounds. PMID:19417144

  1. The Role of HDAC6 in Cancer

    PubMed Central

    Aldana-Masangkay, Grace I.; Sakamoto, Kathleen M.

    2011-01-01

    Histone deacetylase 6 (HDAC6), a member of the HDAC family whose major substrate is α-tubulin, has become a target for drug development to treat cancer due to its major contribution in oncogenic cell transformation. Overexpression of HDAC6 correlates with tumorigenesis and improved survival; therefore, HDAC6 may be used as a marker for prognosis. Previous work demonstrated that in multiple myeloma cells, inhibition of HDAC6 results in apoptosis. Furthermore, HDAC6 is required for the activation of heat-shock factor 1 (HSF1), an activator of heat-shock protein encoding genes (HSPs) and CYLD, a cylindromatosis tumor suppressor gene. HDAC6 contributes to cancer metastasis since its upregulation increases cell motility in breast cancer MCF-7 cells and its interaction with cortactin regulates motility. HDAC6 also affects transcription and translation by regulating the heat-shock protein 90 (Hsp90) and stress granules (SGs), respectively. This review will discuss the role of HDAC6 in the pathogenesis and treatment of cancer. PMID:21076528

  2. 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.

  3. Design, synthesis, 3D pharmacophore, QSAR, and docking studies of carboxylic acid derivatives as Histone Deacetylase inhibitors and cytotoxic agents.

    PubMed

    Abdel-Atty, Mona M; Farag, Nahla A; Kassab, Shaymaa E; Serya, Rabah A T; Abouzid, Khaled A M

    2014-12-01

    In this study, five series of (E)-6-(4-substituted phenyl)-4-oxohex-5-enoic acids IIb-f (E), (E)-3-(4-(substituted)-phenyl)acrylic acids IIIa-g (E), 4-(4-(substituted)phenylamino)-4-oxobutanoic acids VIa,b,e, 5-(4-(substituted)phenylamino)-5-oxopentanoic acids VIIa,f and 2-[(4-(substituted)phenyl) carbamoyl]benzoic acids VIIIa,e were designed and synthesized. Selected compounds were screened in vitro for their cytotoxic effect on 60 human NCI tumor cell lines. Compound IIf (E) displayed significant inhibitory activity against NCI Non-Small Cell Lung A549/ATCC Cancer cell line (68% inhibition) and NCI-H460 Cancer cell line (66% inhibition). Moreover, the final compounds were evaluated in vitro for their cytotoxic activity on HepG2 Cancer cell line in which histone deacetylase (HDAC) is overexpressed. Compounds IIc (E), IIf (E), IIIb (E), and IIIg (E) exhibited the highest cytotoxic activity against HepG2 human cancer cell lines with IC50 ranging from 2.27 to 10.71μM. In addition, selected compounds were tested on histone deacetylase isoforms (HDAC1-11). Molecular docking simulation was also carried out for HDLP enzyme to investigate their HDAC binding affinity. In addition, generation of 3D-pharmacophore model and quantitative structure activity relationship (QSAR) models were combined to explore the structural requirements controlling the observed cytotoxic properties.

  4. 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

  5. HDAC Inhibition Elicits Myocardial Protective Effect through Modulation of MKK3/Akt-1

    PubMed Central

    Zhao, Ting C.; Du, Jianfeng; Zhuang, Shugang; Liu, Paul; Zhang, Ling X.

    2013-01-01

    We and others have demonstrated that HDAC inhibition protects the heart against myocardial injury. It is known that Akt-1 and MAP kinase play an essential role in modulation of myocardial protection and cardiac preconditioning. Our recent observations have shown that Akt-1 was activated in post-myocardial infarction following HDAC inhibition. However, it remains unknown whether MKK3 and Akt-1 are involved in HDAC inhibition-induced myocardial protection in acute myocardial ischemia and reperfusion injury. We sought to investigate whether the genetic disruption of Akt-1 and MKK3 eliminate cardioprotection elicited by HDAC inhibition and whether Akt-1 is associated with MKK3 to ultimately achieve protective effects. Adult wild type and MKK3−/−, Akt-1−/− mice received intraperitoneal injections of trichostatin A (0.1mg/kg), a potent inhibitor of HDACs. The hearts were subjected to 30 min myocardial ischemia/30 min reperfusion in the Langendorff perfused heart after twenty four hours to elicit pharmacologic preconditioning. Left ventricular function was measured, and infarct size was determined. Acetylation and phosphorylation of MKK3 were detected and disruption of Akt-1 abolished both acetylation and phosphorylation of MKK3. HDAC inhibition produces an improvement in left ventricular functional recovery, but these effects were abrogated by disruption of either Akt-1 or MKK3. Disruption of Akt-1 or MKK3 abolished the effects of HDAC inhibition-induced reduction of infarct size. Trichostatin A treatment resulted in an increase in MKK3 phosphorylation or acetylation in myocardium. Taken together, these results indicate that stimulation of the MKK3 and Akt-1 pathway is a novel approach to HDAC inhibition -induced cardioprotection. PMID:23762381

  6. Combined PDGFR and HDAC Inhibition Overcomes PTEN Disruption in Chordoma

    PubMed Central

    Kassam, Amin B.; Park, Myung-Jin; Gardner, Paul; Prevedello, Daniel; Henry, Stephanie; Horbinski, Craig; Beumer, Jan H.; Tawbi, Hussein; Williams, Brian J.; Shaffrey, Mark E.; Egorin, Merrill J.; Abounader, Roger; Park, Deric M.

    2015-01-01

    Background The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR). Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway. Methods Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 of the 23 specimens, and chordoma cell lines, UCH-1 and UCH-2, were used for in vitro experiments. Results Loss of heterozygosity (LOH) at the phosphatase and tensin homolog (PTEN) locus was observed in 6 specimens (26%). PTEN disruption statistically correlated with increased Ki-67 proliferation index, an established marker of poor outcome for chordoma. Compared to wild type, PTEN deficient chordomas displayed increased proliferative rate, and responded less favorably to PDGFR inhibition. PTEN gene restoration abrogated this growth advantage. Chordomas are characterized by intratumoral hypoxia and local invasion, and histone deacetylase (HDAC) inhibitors are capable of attenuating both hypoxic signaling and cell migration. The combination of PDGFR and HDAC inhibition effectively disrupted growth and invasion of PTEN deficient chordoma cells. Conclusions Loss of heterozygosity of the PTEN gene seen in a subset of chordomas is associated with aggressive in vitro behavior and strongly correlates with increased Ki-67 proliferative index. Combined inhibition of PDGFR and HDAC attenuates proliferation and invasion in chordoma cells deficient for PTEN. PMID:26247786

  7. HDAC3 impacts multiple oncogenic pathways in colon cancer cells with effects on Wnt and vitamin D signaling.

    PubMed

    Godman, Cassandra A; Joshi, Rashmi; Tierney, Brendan R; Greenspan, Emily; Rasmussen, Theodore P; Wang, Hsin-Wei; Shin, Dong-Guk; Rosenberg, Daniel W; Giardina, Charles

    2008-10-01

    Histone deacetylase 3 (HDAC3) is overexpressed in approximately half of all colon adenocarcinomas. We took an RNAi approach to determine how HDAC3 influenced chromatin modifications and the expression of growth regulatory genes in colon cancer cells. A survey of histone modifications revealed that HDAC3 knockdown in SW480 cells significantly increased histone H4-K12 acetylation, a modification present during chromatin assembly that has been implicated in imprinting. This modification was found to be most prominent in proliferating cells in the intestinal crypt and in APC(Min) tumors, but was less pronounced in the tumors that overexpress HDAC3. Gene expression profiling of SW480 revealed that HDAC3 shRNA impacted the expression of genes in the Wnt and vitamin D signaling pathways. The impact of HDAC3 on Wnt signaling was complex, with both positive and negative effects observed. However, long-term knockdown of HDAC3 suppressed beta-catenin translocation from the plasma membrane to the nucleus, and increased expression of Wnt inhibitors TLE1, TLE4 and SMO. HDAC3 knockdown also enhanced expression of the TLE1 and TLE4 repressors in HT-29 and HCT116 cells. HDAC3 shRNA enhanced expression of the vitamin D receptor in SW480 and HCT116 cells, and rendered SW480 cells sensitive to 1,25-dihydroxyvitamin D3. We propose that HDAC3 overexpression alters the epigenetic programming of colon cancer cells to impact intracellular Wnt signaling and their sensitivity to external growth regulation by vitamin D.

  8. cis-Cinnamic acid selective suppressors distinct from auxin inhibitors.

    PubMed

    Okuda, Katsuhiro; Nishikawa, Keisuke; Fukuda, Hiroshi; Fujii, Yoshiharu; Shindo, Mitsuru

    2014-01-01

    The activity of cis-cinnamic acid (cis-CA), one of the allelochemicals, in plants is very similar to that of indole-3-acetic acid (IAA), a natural auxin, and thus cis-CA has long been believed to be an analog of auxin. We have reported some structure-activity relationships studies by synthesizing over 250 cis-CA derivatives and estimating their inhibitory activities on root growth inhibition in lettuce. In this study, the compounds that showed low- or no-activity on root growth inhibition were recruited as candidates suppressors against cis-CA and/or auxin and tested for their activity. In the presence of cis-CA, lettuce root growth was inhibited; however, the addition of some cis-CA derivatives restored control-level root growth. Four compounds, (Z)-3-(4-isopropylphenyl)acrylic acid, (Z)-3-(3-butoxyphenyl)acrylic acid, (Z)-3-[3-(pentyloxy)phenyl]acrylic acid, and (Z)-3-(naphthalen-1-yl)acrylic acid were selected as candidates for a cis-CA selective suppressor they allowed the recovery of root growth from inhibition by cis-CA treatment without any effects on the IAA-induced effect or elongating activity by themselves. Three candidates significantly ameliorated the root shortening by the potent inhibitor derived from cis-CA. In brief, we have found some cis-CA selective suppressors which have never been reported from inactive cis-CA derivatives for root growth inhibition. cis-CA selective suppressors will play an important role in elucidating the mechanism of plant growth regulation.

  9. Focus on acetylation: the role of histone deacetylase inhibitors in cancer therapy and beyond.

    PubMed

    Konstantinopoulos, Panagiotis A; Karamouzis, Michalis V; Papavassiliou, Athanasios G

    2007-05-01

    Reversal of tumorigenic epigenetic alterations is an exciting strategy for anticancer drug development. Pharmacologic inhibition of histone deacetylases (HDACs) induces differentiation, proliferation arrest and apoptosis of cancer cells. In addition to their effects on histones, HDAC inhibitors increase the acetylation level of several non-histone proteins, such as transcription factors, cytoskeletal proteins and molecular chaperones, which are crucial in tumorigenesis. Most importantly, the therapeutic potential of HDAC inhibitors goes well beyond carcinogenesis and may include neurodegenerative and inflammatory disorders. This editorial discusses the implication of HDACs in carcinogenesis, the molecular basis of the selectivity of HDAC inhibitors and their possible therapeutic role in non-malignant pathologic conditions.

  10. Computational Studies on the Histone Deacetylases and the Design of Selective Histone Deacetylase Inhibitors

    PubMed Central

    Wang, Difei

    2009-01-01

    The catalytic activity of the histone deacetylase (HDAC) enzymes is directly relevant to the pathogenesis of cancer as well as several other diseases. HDAC inhibitors have been shown to have the potential to treat several types of cancers. The role of computational study of the HDAC enzymes is reviewed, with particular emphasis on the important role of molecular modeling to the development of HDAC inhibitors with improved efficacy and selectivity. The use of two computational approaches—one structure-based, and the second ligand-based—toward inhibitors against the different HDAC sub-classes, are summarized. PMID:19355989

  11. Identification of Bidentate Salicylic Acid Inhibitors of PTP1B

    PubMed Central

    2015-01-01

    PTP1B is a master regulator in the insulin and leptin metabolic pathways. Hyper-activated PTP1B results in insulin resistance and is viewed as a key factor in the onset of type II diabetes and obesity. Moreover, inhibition of PTP1B expression in cancer cells dramatically inhibits cell growth in vitro and in vivo. Herein, we report the computationally guided optimization of a salicylic acid-based PTP1B inhibitor 6, identifying new and more potent bidentate PTP1B inhibitors, such as 20h, which exhibited a > 4-fold improvement in activity. In CHO-IR cells, 20f, 20h, and 20j suppressed PTP1B activity and restored insulin receptor phosphorylation levels. Notably, 20f, which displayed a 5-fold selectivity for PTP1B over the closely related PTPσ protein, showed no inhibition of PTP-LAR, PRL2 A/S, MKPX, or papain. Finally, 20i and 20j displayed nanomolar inhibition of PTPσ, representing interesting lead compounds for further investigation. PMID:26396684

  12. Study on polyepoxysuccinic acid reverse osmosis scale inhibitor.

    PubMed

    Sun, Yonghong; Xiang, Wenhua; Wang, Ying

    2009-01-01

    The effectiveness and applicability of polyepoxysuccinic acid (PESA) as a reverse osmosis (RO) scale inhibitor were studied using static and dynamic methods. In the static study, PESA performed very well in the treatment of water samples with various types of scale that commonly exist in RO water (i.e., CaCO3, CaSO4, BaSO4, SrSO4), showing an average scale inhibition ratio of above 90% at a dosage of 10 mg/L. SEM analysis showed a disordered CaCO3 crystal in the presence of PESA, suggesting the scale-inhibiting mechanism. In the dynamic experiment, PESA also showed great performance in the treatment of 10 samples of synthetic tap water or sea water with different ion composition (i.e., Ca(2+), HCO3(-), Fe(3+), Al(3+)). After one cycle (7 d) of RO treatment of each sample at full recycle operation mode under a constant pressure of 1×10(6) Pa, the differences in water permeability and desalination ratio among samples are within 5%, suggesting that PESA is capable of treating waters of different quality, and has a strong resistance to ions that are harmful to scale inhibiting (i.e., Fe(3+) and Al(3+)). All these results suggest that PESA should be an effective scale inhibitor that is applicable to RO treatment of waters with a wide range of ion compositions.

  13. 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

  14. HIV-1 Tat Upregulates Expression of Histone Deacetylase-2 (HDAC2) in Human Neurons: Implication for HIV-Associated Neurocognitive Disorder (HAND)

    PubMed Central

    Saiyed, Zainulabedin M.; Gandhi, Nimisha; Agudelo, Marisela; Napuri, Jessica; Samikkannu, Thangavel; Reddy, Pichili VB; Khatavkar, Pradnya; Yndart, Adriana; Saxena, Shailendra K.; Nair, Madhavan P.N.

    2011-01-01

    Histone deacetylases (HDACs) play a pivotal role in epigenetic regulation of transcription and homeostasis of protein acetylation in histones and other proteins involved in chromatin remodeling. Histone hypoacetylation and transcriptional dysfunction have been shown to be associated with a variety of neurodegenerative diseases. More recently, neuron specific overexpression of HDAC2 has been shown to modulate synaptic plasticity and learning behavior in mice. However, the role of HDAC2 in development of HIV-associated neurocognitive disorders (HAND) is not reported. Herein we report that HIV-1 Tat protein upregulate HDAC2 expression in neuronal cells leading to transcriptional repression of genes involved in synaptic plasticity and neuronal function thereby contributing to the progression of HAND. Our results indicate upregulation of HDAC2 by Tat treatment in dose and time dependant manner by human neuroblastoma SK-N-MC cells and primary human neurons. Further, HDAC2 overexpression was associated with concomitant downregulation in CREB and CaMKIIa genes that are known to regulate neuronal activity. These observed effects were completely blocked by HDAC2 inhibition. These results for the first time suggest the possible role of HDAC2 in development of HAND. Therefore, use of HDAC2 specific inhibitor in combination with HAART may be of therapeutic value in treatment of neurocognitive disorders observed in HIV-1 infected individuals. PMID:21315782

  15. 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

    Singh, Raushan K; Suzuki, Takayoshi; Mandal, Tanmay; Balsubramanian, Narayanaganesh; Haldar, Manas; Mueller, Dustin J; Strode, Jerrod A; Cook, Gregory; Mallik, Sanku; Srivastava, D K

    2014-12-01

    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.

  16. 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

  17. 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

    Singh, Raushan K; Suzuki, Takayoshi; Mandal, Tanmay; Balsubramanian, Narayanaganesh; Haldar, Manas; Mueller, Dustin J; Strode, Jerrod A; Cook, Gregory; Mallik, Sanku; Srivastava, D K

    2014-12-01

    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

  18. Class I HDACs Affect DNA Replication, Repair, and Chromatin Structure: Implications for Cancer Therapy

    PubMed Central

    Stengel, Kristy R.

    2015-01-01

    Abstract Significance: The contribution of epigenetic alterations to cancer development and progression is becoming increasingly clear, prompting the development of epigenetic therapies. Histone deacetylase inhibitors (HDIs) represent one of the first classes of such therapy. Two HDIs, Vorinostat and Romidepsin, are broad-spectrum inhibitors that target multiple histone deacetylases (HDACs) and are FDA approved for the treatment of cutaneous T-cell lymphoma. However, the mechanism of action and the basis for the cancer-selective effects of these inhibitors are still unclear. Recent Advances: While the anti-tumor effects of HDIs have traditionally been attributed to their ability to modify gene expression after the accumulation of histone acetylation, recent studies have identified the effects of HDACs on DNA replication, DNA repair, and genome stability. In addition, the HDIs available in the clinic target multiple HDACs, making it difficult to assign either their anti-tumor effects or their associated toxicities to the inhibition of a single protein. However, recent studies in mouse models provide insights into the tissue-specific functions of individual HDACs and their involvement in mediating the effects of HDI therapy. Critical Issues: Here, we describe how altered replication contributes to the efficacy of HDAC-targeted therapies as well as discuss what knowledge mouse models have provided to our understanding of the specific functions of class I HDACs, their potential involvement in tumorigenesis, and how their disruption may contribute to toxicities associated with HDI treatment. Future Directions: Impairment of DNA replication by HDIs has important therapeutic implications. Future studies should assess how best to exploit these findings for therapeutic gain. Antioxid. Redox Signal. 23, 51–65. PMID:24730655

  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. Histone deacetylase inhibitor-induced cancer stem cells exhibit high pentose phosphate pathway metabolism

    PubMed Central

    Debeb, Bisrat G.; Lacerda, Lara; Larson, Richard; Wolfe, Adam R.; Krishnamurthy, Savitri; Reuben, James M.; Ueno, Naoto T.; Gilcrease, Michael; Woodward, Wendy A.

    2016-01-01

    Purpose We recently demonstrated that histone deacetylase (HDAC) inhibitors can “reprogram” differentiated triple-negative breast cancer cells to become quiescent stem-like cancer cells. We hypothesized that the metabolic state of such cells differs from that of their differentiated progeny. Results In untreated cells, glucose uptake was higher in ALDH+ cells than in ALDH− cells (p = 0.01) but lactate production was not different; treating ALDH− or ALDH+ cells with VA or SAHA similarly increased glucose uptake without changing lactate production but upregulated G6PD, a rate-limiting enzyme in pentose phosphate pathway metabolism. NADPH production was higher in HDAC inhibitor-treated stem-like cells than in vehicle-treated cells (p < 0.05). Two G6PD inhibitors, 6-aminonicotinamide and dehydroepiandrosterone, decreased mammosphere formation efficiency and ALDH activity and 6-aminonicotinamide reduced the VA-induced increase in ALDH+ cells. Finally, patients expressing high G6PD mRNA had significantly worse overall survival (p < 0.001), and patients with high G6PD protein showed a similar trend towards worse disease-specific survival (p = 0.06). Methods Glucose consumption, lactate and NADPH production, and reactive oxygen species generation were compared in aldehyde dehydrogenase (ALDH)-positive and –negative cells in the presence or absence of the HDAC inhibitors valproic acid (VA) or suberoylanilide hydroxamic acid (SAHA). Glucose-6-phosphate dehydrogenase (G6PD) expression was evaluated in a tissue microarray from 94 patients with node-positive invasive breast carcinoma and in two publically available databases and correlated with overall survival. Conclusions Energy metabolism in HDAC inhibitor-induced stem-like cancer cells differed sharply from that of differentiated cell types. HDAC inhibitor-induced dedifferentiation promoted metabolic reprogramming into the pentose phosphate pathway, which is targeted effectively by G6PD inhibition. These findings

  1. HDAC1 inhibition by melatonin leads to suppression of lung adenocarcinoma cells via induction of oxidative stress and activation of apoptotic pathways.

    PubMed

    Fan, Chongxi; Pan, Yunhu; Yang, Yang; Di, Shouyin; Jiang, Shuai; Ma, Zhiqiang; Li, Tian; Zhang, Zhipei; Li, Weimiao; Li, Xiaofei; Reiter, Russel J; Yan, Xiaolong

    2015-10-01

    Melatonin is an indoleamine synthesized in the pineal gland that shows a wide range of physiological and pharmacological functions, including anticancer effects. In this study, we investigated the effect of melatonin on drug-induced cellular apoptosis against the cultured human lung adenocarcinoma cells and explored the role of histone deacetylase (HDAC) signaling in this process. The results showed that melatonin treatment led to a dose- and time-dependent decrease in the viability of human A549 and PC9 lung adenocarcinoma cells. Additionally, melatonin exhibited potent anticancer activity in vitro, as evidenced by reductions of the cell adhesion, migration, and the intracellular glutathione (GSH) level and increases in the apoptotic index, caspase 3 activity, and reactive oxygen species (ROS) in A549 and PC9 cells. Melatonin treatment also influenced the expression of HDAC-related molecules (HDAC1 and Ac-histone H3), upregulated the apoptosis-related molecules (PUMA and Bax), and downregulated the proliferation-related molecule (PCNA) and the anti-apoptosis-related molecule (Bcl2). Furthermore, the inhibition of HDAC signaling using HDAC1 siRNA or SAHA (a potent pan-inhibitor of HDACs) sensitized A549 and PC9 cells to the melatonin treatment. In summary, these data indicate that in vitro-administered melatonin is a potential suppressor of lung adenocarcinoma cells by the targeting of HDAC signaling and suggest that melatonin in combination with HDAC inhibitors may be a novel therapeutic intervention for human lung adenocarcinoma.

  2. Feedback Activation of Leukemia Inhibitory Factor Receptor Limits Response to Histone Deacetylase Inhibitors in Breast Cancer.

    PubMed

    Zeng, Hanlin; Qu, Jia; Jin, Nan; Xu, Jun; Lin, Chenchu; Chen, Yi; Yang, Xinying; He, Xiang; Tang, Shuai; Lan, Xiaojing; Yang, Xiaotong; Chen, Ziqi; Huang, Min; Ding, Jian; Geng, Meiyu

    2016-09-12

    Histone deacetylase (HDAC) inhibitors have demonstrated clinical benefits in subtypes of hematological malignancies. However, the efficacy of HDAC inhibitors in solid tumors remains uncertain. This study takes breast cancer as a model to understand mechanisms accounting for limited response of HDAC inhibitors in solid tumors and to seek combination solutions. We discover that feedback activation of leukemia inhibitory factor receptor (LIFR) signaling in breast cancer limits the response to HDAC inhibition. Mechanistically, HDAC inhibition increases histone acetylation at the LIFR gene promoter, which recruits bromodomain protein BRD4, upregulates LIFR expression, and activates JAK1-STAT3 signaling. Importantly, JAK1 or BRD4 inhibition sensitizes breast cancer to HDAC inhibitors, implicating combination inhibition of HDAC with JAK1 or BRD4 as potential therapies for breast cancer. PMID:27622335

  3. HDAC Family Members Intertwined in the Regulation of Autophagy: A Druggable Vulnerability in Aggressive Tumor Entities

    PubMed Central

    Koeneke, Emily; Witt, Olaf; Oehme, Ina

    2015-01-01

    The exploitation of autophagy by some cancer entities to support survival and dodge death has been well-described. Though its role as a constitutive process is important in normal, healthy cells, in the milieu of malignantly transformed and highly proliferative cells, autophagy is critical for escaping metabolic and genetic stressors. In recent years, the importance of histone deacetylases (HDACs) in cancer biology has been heavily investigated, and the enzyme family has been shown to play a role in autophagy, too. HDAC inhibitors (HDACi) are being integrated into cancer therapy and clinical trials are ongoing. The effect of HDACi on autophagy and, conversely, the effect of autophagy on HDACi efficacy are currently under investigation. With the development of HDACi that are able to selectively target individual HDAC isozymes, there is great potential for specific therapy that has more well-defined effects on cancer biology and also minimizes toxicity. Here, the role of autophagy in the context of cancer and the interplay of this process with HDACs will be summarized. Identification of key HDAC isozymes involved in autophagy and the ability to target specific isozymes yields the potential to cripple and ultimately eliminate malignant cells depending on autophagy as a survival mechanism. PMID:25915736

  4. Sodium valproate potentiates staurosporine-induced apoptosis in neuroblastoma cells via Akt/survivin independently of HDAC inhibition.

    PubMed

    Shah, Reecha D; Jagtap, Jayashree C; Mruthyunjaya, S; Shelke, Ganesh V; Pujari, Radha; Das, Gowry; Shastry, Padma

    2013-04-01

    Sodium valproate (VPA) has been recently identified as a selective class I histone deacetylase (HDAC) inhibitor and explored for its potential as an anti-cancer agent. The anti-cancer properties of VPA are generally attributed to its HDAC inhibitory activity indicating a clear overlap of these two actions, but the underlying mechanisms of its anti-tumor effects are not clearly elucidated. The present study aimed to delineate the molecular mechanism of VPA in potentiating cytotoxic effects of anti-cancer drugs with focus on inhibition of HDAC activity. Using human neuroblastoma cell lines, SK-N-MC, SH-SY5Y, and SK-N-SH, we show that non-toxic dose (2 mM) of VPA enhanced staurosporine (STS)-induced cell death as assessed by MTT assay, PARP cleavage, hypodiploidy, and caspase 3 activity. Mechanistically, the effect of VPA was mediated by down regulation of survivin, an anti-apoptotic protein crucial in resistance to STS-mediated cytotoxicity, through Akt pathway. Knock down of class I HDAC isoforms remarkably inhibited HDAC activity comparable with that of VPA but had no effect on STS-induced apoptosis. Moreover, MS-275, a structurally distinct class I HDAC inhibitor did not affect STS-mediated apoptosis, nor decrease the levels of survivin and Akt. Valpromide (VPM), an amide analog of VPA that does not inhibit HDAC also potentiated cell death in NB cells associated with decreased survivin and Akt levels suggesting that HDAC inhibition might not be crucial for STS-induced apoptosis. The study provides new information on the possible molecular mechanism of VPA in apoptosis that can be explored in combination therapy in cancer.

  5. Terreic Acid, a Quinone Epoxide Inhibitor of Bruton's Tyrosine Kinase

    NASA Astrophysics Data System (ADS)

    Kawakami, Yuko; Hartman, Stephen E.; Kinoshita, Eiji; Suzuki, Hidefumi; Kitaura, Jiro; Yao, Libo; Inagaki, Naoki; Franco, Alessandra; Hata, Daisuke; Maeda-Yamamoto, Mari; Fukamachi, Hiromi; Nagai, Hiroichi; Kawakami, Toshiaki

    1999-03-01

    Bruton's tyrosine kinase (Btk) plays pivotal roles in mast cell activation as well as in B cell development. Btk mutations lead to severe impairments in proinflammatory cytokine production induced by cross-linking of high-affinity IgE receptor on mast cells. By using an in vitro assay to measure the activity that blocks the interaction between protein kinase C and the pleckstrin homology domain of Btk, terreic acid (TA) was identified and characterized in this study. This quinone epoxide specifically inhibited the enzymatic activity of Btk in mast cells and cell-free assays. TA faithfully recapitulated the phenotypic defects of btk mutant mast cells in high-affinity IgE receptor-stimulated wild-type mast cells without affecting the enzymatic activities and expressions of many other signaling molecules, including those of protein kinase C. Therefore, this study confirmed the important roles of Btk in mast cell functions and showed the usefulness of TA in probing into the functions of Btk in mast cells and other immune cell systems. Another insight obtained from this study is that the screening method used to identify TA is a useful approach to finding more efficacious Btk inhibitors.

  6. Histone Deacetylase Inhibitors in Clinical Studies as Templates for New Anticancer Agents

    PubMed Central

    Mottamal, Madhusoodanan; Zheng, Shilong; Huang, Tien L.; Wang, Guangdi

    2015-01-01

    Histone dacetylases (HDACs) are a group of enzymes that remove acetyl groups from histones and regulate expression of tumor suppressor genes. They are implicated in many human diseases, especially cancer, making them a promising therapeutic target for treatment of the latter by developing a wide variety of inhibitors. HDAC inhibitors interfere with HDAC activity and regulate biological events, such as cell cycle, differentiation and apoptosis in cancer cells. As a result, HDAC inhibitor-based therapies have gained much attention for cancer treatment. To date, the FDA has approved three HDAC inhibitors for cutaneous/peripheral T-cell lymphoma and many more HDAC inhibitors are in different stages of clinical development for the treatment of hematological malignancies as well as solid tumors. In the intensifying efforts to discover new, hopefully more therapeutically efficacious HDAC inhibitors, molecular modeling-based rational drug design has played an important role in identifying potential inhibitors that vary in molecular structures and properties. In this review, we summarize four major structural classes of HDAC inhibitors that are in clinical trials and different computer modeling tools available for their structural modifications as a guide to discover additional HDAC inhibitors with greater therapeutic utility. PMID:25738536

  7. Synergistic effects of combined treatment with histone deacetylase inhibitor suberoylanilide hydroxamic acid and TRAIL on human breast cancer cells

    PubMed Central

    Zhou, Weiqiang; Feng, Xiuyan; Han Han; Guo, Shanchun; Wang, Guangdi

    2016-01-01

    Previous studies showed that either histone deacetylase (HDAC) inhibitors or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce apoptosis in tumor cells including breast cancer. However, the underling mechanisms of combining HDAC inhibitors with TRAIL in the treatment of breast cancer are poorly understood. In this study, we determined the ability of SAHA and TRAIL as single agents or in combination to inhibit the growth and survival of MCF-7 and MDA-MB-231 breast cancer cells. Our results demonstrate that the distinct effects of SAHA or TRAIL individually and in combination on the proliferation, cell viability, apoptosis, cell cycle distribution, and morphological changes of MDA-MB-231 and MCF-7 cells. We further determined the different effects of SAHA or TRAIL alone and combining SAHA with TRAIL on the expression of a number of apoptosis-related molecules, cell cycle, growth factors and their receptors in cancer cells. Our results demonstrated that the combinatorial treatment of SAHA and TRAIL may target multiple pathways and serve as an effective therapeutic strategy against breast cancer. An improved understanding of the molecular mechanisms may facilitate either SAHA or TRAIL targeted use and the selection of suitable combinations. PMID:27292433

  8. Induction of truncated form of tenascin-X (XB-S) through dissociation of HDAC1 from SP-1/HDAC1 complex in response to hypoxic conditions

    SciTech Connect

    Kato, Akari; Endo, Toshiya; Abiko, Shun; Ariga, Hiroyoshi; Matsumoto, Ken-ichi

    2008-08-15

    ABSTRACT: XB-S is an amino-terminal truncated protein of tenascin-X (TNX) in humans. The levels of the XB-S transcript, but not those of TNX transcripts, were increased upon hypoxia. We identified a critical hypoxia-responsive element (HRE) localized to a GT-rich element positioned from - 1410 to - 1368 in the XB-S promoter. Using an electrophoretic mobility shift assay (EMSA), we found that the HRE forms a DNA-protein complex with Sp1 and that GG positioned in - 1379 and - 1378 is essential for the binding of the nuclear complex. Transfection experiments in SL2 cells, an Sp1-deficient model system, with an Sp1 expression vector demonstrated that the region from - 1380 to - 1371, an HRE, is sufficient for efficient activation of the XB-S promoter upon hypoxia. The EMSA and a chromatin immunoprecipitation (ChIP) assay showed that Sp1 together with the transcriptional repressor histone deacetylase 1 (HDAC1) binds to the HRE of the XB-S promoter under normoxia and that hypoxia causes dissociation of HDAC1 from the Sp1/HDAC1 complex. The HRE promoter activity was induced in the presence of a histone deacetylase inhibitor, trichostatin A, even under normoxia. Our results indicate that the hypoxia-induced activation of the XB-S promoter is regulated through dissociation of HDAC1 from an Sp1-binding HRE site.

  9. The cyclin-dependent kinase inhibitor p21 is a crucial target for histone deacetylase 1 as a regulator of cellular proliferation.

    PubMed

    Zupkovitz, Gordin; Grausenburger, Reinhard; Brunmeir, Reinhard; Senese, Silvia; Tischler, Julia; Jurkin, Jennifer; Rembold, Martina; Meunier, Dominique; Egger, Gerda; Lagger, Sabine; Chiocca, Susanna; Propst, Fritz; Weitzer, Georg; Seiser, Christian

    2010-03-01

    Histone deacetylases (HDACs) are chromatin-modifying enzymes that are involved in the regulation of proliferation, differentiation and development. HDAC inhibitors induce cell cycle arrest, differentiation, or apoptosis in tumor cells and are therefore promising antitumor agents. Numerous genes were found to be deregulated upon HDAC inhibitor treatment; however, the relevant target enzymes are still unidentified. HDAC1 is required for mouse development and unrestricted proliferation of embryonic stem cells. We show here that HDAC1 reversibly regulates cellular proliferation and represses the cyclin-dependent kinase inhibitor p21 in embryonic stem cells. Disruption of the p21 gene rescues the proliferation phenotype of HDAC1(-/-) embryonic stem cells but not the embryonic lethality of HDAC1(-/-) mice. In the absence of HDAC1, mouse embryonic fibroblasts scarcely undergo spontaneous immortalization and display increased p21 expression. Chromatin immunoprecipitation assays demonstrate a direct regulation of the p21 gene by HDAC1 in mouse embryonic fibroblasts. Transformation with simian virus 40 large T antigen or ablation of p21 restores normal immortalization of primary HDAC1(-/-) fibroblasts. Our data demonstrate that repression of the p21 gene is crucial for HDAC1-mediated control of proliferation and immortalization. HDAC1 might therefore be one of the relevant targets for HDAC inhibitors as anticancer drugs.

  10. HDAC1 controls CIP2A transcription in human colorectal cancer cells

    PubMed Central

    Balliu, Manjola; Cellai, Cristina; Lulli, Matteo; Laurenzana, Anna; Torre, Eugenio; Vannucchi, Alessandro Maria; Paoletti, Francesco

    2016-01-01

    This work describes the effectiveness of HDAC-inhibitor (S)-2 towards colorectal cancer (CRC) HCT116 cells in vitro by inducing cell cycle arrest and apoptosis, and in vivo by contrasting tumour growth in mice xenografts. Among the multifaceted drug-induced events described herein, an interesting link has emerged between the oncoprotein histone deacetylase HDAC1 and the oncogenic Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) which is overexpressed in several cancers including CRCs. HDAC1 inhibition by (S)-2 or specific siRNAs downregulates CIP2A transcription in three different CRC cell lines, thus restoring the oncosuppressor phosphatase PP2A activity that is reduced in most cancers. Once re-activated, PP2A dephosphorylates pGSK-3β(ser9) which phosphorylates β-catenin that remains within the cytosol where it undergoes degradation. The decreased amount/activity of β-catenin transcription factor prompts cell growth arrest by diminishing c-Myc and cyclin D1 expression and abrogating the prosurvival Wnt/β-catenin signaling pathway. These results are the first evidence that the inhibition of HDAC1 by (S)-2 downregulates CIP2A transcription and unleashes PP2A activity, thus inducing growth arrest and apoptosis in CRC cells. PMID:27029072

  11. Purification, characterization, and complete amino acid sequence of a trypsin inhibitor from amaranth (Amaranthus hypochondriacus) seeds.

    PubMed Central

    Valdes-Rodriguez, S; Segura-Nieto, M; Chagolla-Lopez, A; Verver y Vargas-Cortina, A; Martinez-Gallardo, N; Blanco-Labra, A

    1993-01-01

    A protein proteinase inhibitor was purified from a seed extract of amaranth (Amaranthus hypochondriacus) by precipitation with (NH4)2SO4, gel-filtration chromatography, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography. It is a 69-amino acid protein with a high content of valine, arginine, and glutamic acid, but lacking in methionine. The inhibitor has a relative molecular weight of 7400 and an isoelectric point of 7.5. It is a serine proteinase inhibitor that recognizes chymotrypsin, trypsin, and trypsin-like proteinase activities extracted from larvae of the insect Prostephanus truncatus. This inhibitor belongs to the potato-I inhibitor family, showing the closest homology (59.5%) with the Lycopersicum peruvianum trypsin inhibitor, and (51%) with the proteinase inhibitor 5 extracted from the seeds of Cucurbita maxima. The position of the lysine-aspartic acid residues present in the active site of the amaranth inhibitor are found in almost the same relative position as in the inhibitor from C. maxima. PMID:8290633

  12. HDAC6 regulates glucocorticoid receptor signaling in serotonin pathways with critical impact on stress resilience.

    PubMed

    Espallergues, Julie; Teegarden, Sarah L; Veerakumar, Avin; Boulden, Janette; Challis, Collin; Jochems, Jeanine; Chan, Michael; Petersen, Tess; Deneris, Evan; Matthias, Patrick; Hahn, Chang-Gyu; Lucki, Irwin; Beck, Sheryl G; Berton, Olivier

    2012-03-28

    Genetic variations in certain components of the glucocorticoid receptor (GR) chaperone complex have been associated with the development of stress-related affective disorders and individual variability in therapeutic responses to antidepressants. Mechanisms that link GR chaperoning and stress susceptibility are not well understood. Here, we show that the effects of glucocorticoid hormones on socioaffective behaviors are critically regulated via reversible acetylation of Hsp90, a key component of the GR chaperone complex. We provide pharmacological and genetic evidence indicating that the cytoplasmic lysine deacetylase HDAC6 controls Hsp90 acetylation in the brain, and thereby modulates Hsp90-GR protein-protein interactions, as well as hormone- and stress-induced GR translocation, with a critical impact on GR downstream signaling and behavior. Pet1-Cre-driven deletion of HDAC6 in serotonin neurons, the densest HDAC6-expressing cell group in the mouse brain, dramatically reduced acute anxiogenic effects of the glucocorticoid hormone corticosterone in the open-field, elevated plus maze, and social interaction tests. Serotonin-selective depletion of HDAC6 also blocked the expression of social avoidance in mice exposed to chronic social defeat and concurrently prevented the electrophysiological and morphological changes induced, in serotonin neurons, by this murine model of traumatic stress. Together, these results identify HDAC6 inhibition as a potential new strategy for proresilience and antidepressant interventions through regulation of the Hsp90-GR heterocomplex and focal prevention of GR signaling in serotonin pathways. Our data thus uncover an alternate mechanism by which pan-HDAC inhibitors may regulate stress-related behaviors independently of their action on histones.

  13. Regulation of intestinal serotonin transporter expression via epigenetic mechanisms: role of HDAC2.

    PubMed

    Gill, Ravinder K; Kumar, Anoop; Malhotra, Pooja; Maher, Daniel; Singh, Varsha; Dudeja, Pradeep K; Alrefai, Waddah; Saksena, Seema

    2013-02-15

    The serotonin (5-HT) transporter (SERT) facilitates clearance of extracellular 5-HT by its uptake and internalization. Decreased expression of SERT and consequent high 5-HT levels have been implicated in various diarrheal disorders. Thus, appropriate regulation of SERT is critical for maintenance of 5-HT homeostasis in health and disease. Previous studies demonstrated that SERT is regulated via posttranslational and transcriptional mechanisms. However, the role of epigenetic mechanisms in SERT regulation is not known. Current studies investigated the effects of histone deacetylase (HDAC) inhibition on SERT expression and delineated the mechanisms. Treatment of Caco-2 cells with the pan-HDAC inhibitors butyrate (5 mM) and trichostatin (TSA, 1 μM) decreased SERT mRNA and protein levels. Butyrate- or TSA-induced decrease in SERT was associated with decreased activity of human SERT (hSERT) promoter 1 (upstream of exon 1a), but not hSERT promoter 2 (upstream of exon 2). Butyrate + TSA did not show an additive effect on SERT expression, indicating that mechanisms involving histone hyperacetylation may be involved. Chromatin immunoprecipitation assays demonstrated enrichment of the hSERT promoter 1 (flanking nt -250/+2) with tetra-acetylated histone H3 or H4, which was increased (~3-fold) by butyrate. Interestingly, specific inhibition of HDAC2 (but not HDAC1) utilizing small interfering RNA decreased SERT mRNA and protein levels. The decrease in SERT expression by HDAC inhibition was recapitulated in an in vivo model. SERT mRNA levels were decreased in the ileum and colon of mice fed pectin (increased availability of butyrate) compared with controls fed a fiber-free diet (~50-60%). Our results identify a novel role of HDAC2 as a regulator of SERT gene expression in intestinal epithelial cells.

  14. HDAC6 regulates GR signaling in serotonin pathways with critical impact on stress resilience

    PubMed Central

    Espallergues, Julie; Teegarden, Sarah L.; Veerakumar, Avin; Boulden, Janette; Challis, Collin; Jochems, Jeanine; Chan, Michael; Petersen, Tess; Deneris, Evan; Matthias, Patrick; Hahn, Chang-Gyu; Lucki, Irwin; Beck, Sheryl G.; Berton, Olivier

    2012-01-01

    Genetic variations in certain components of the glucocorticoid receptor (GR) chaperone complex have been associated with the development of stress-related affective disorders and individual variability in therapeutic responses to antidepressants. Mechanisms that link GR chaperoning and stress susceptibility are not well understood. Here, we show that the effects of glucocorticoid hormones on socioaffective behaviors are critically regulated via reversible acetylation of Hsp90, a key component of the GR chaperone complex. We provide pharmacological and genetic evidence indicating that the cytoplasmic lysine deacetylase HDAC6 controls Hsp90 acetylation in the brain, and thereby modulates Hsp90-GR protein-protein interactions, as well as hormone- and stress-induced GR translocation, with a critical impact on GR downstream signaling and behavior. Pet1-Cre driven deletion of HDAC6 in serotonin neurons, the densest HDAC6-expressing cell group in the mouse brain, dramatically reduced acute anxiogenic effects of the glucocorticoid hormone corticosterone in the open field, elevated plus maze, and social interaction tests. Serotonin-selective depletion of HDAC6 also blocked the expression of social avoidance in mice exposed to chronic social defeat and concurrently prevented the electrophysiological and morphological changes induced, in serotonin neurons, by this murine model of traumatic stress. Together, these results identify HDAC6 inhibition as a potential new strategy for pro-resilience and antidepressant interventions through regulation of the Hsp90-GR heterocomplex and focal prevention of GR signaling in serotonin pathways. Our data thus uncover an alternate mechanism by which pan-HDAC inhibitors may regulate stress-related behaviors independently of their action on histones. PMID:22457490

  15. HDAC8-mediated epigenetic reprogramming plays a key role in resistance to anthrax lethal toxin-induced pyroptosis in macrophages*

    PubMed Central

    Ha, Soon-Duck; Han, Chae Young; Reid, Chantelle; Kim, Sung Ouk

    2014-01-01

    Macrophages pre-exposed to a sub-lethal dose of anthrax lethal toxin (LeTx) are refractory to subsequent high cytolytic doses of LeTx, termed toxin-induced resistance (TIR). A small population of TIR cells (2–4%) retains TIR characteristics for up to 5 to 6 weeks. Through studying these long-term TIR cells, we found that a high level of histone deacetylase (HDAC)8 expression was crucial for TIR. Knocking down or inhibition of HDAC8 by siRNAs or the HDAC8-specific inhibitor PCI-34051, respectively, induced expression of the mitochondrial death genes Bcl2 Adenovirus E1B 19 kDa-interacting protein 3 (BNIP3), BNIP3-like (BNIP3L) and Metastatic Lymph Node (MLN)64, and re-sensitized TIR cells to LeTx. Among multiple histone acetylations, histone H3 lysine 27 acetylation (H3K27Ac) was most significantly decreased in TIR cells in an HDAC8-dependent manner, and the association of H3K27Ac with the genomic regions of BNIP3 and MLN64, where HDAC8 was recruited to, was diminished in TIR cells. Furthermore, over-expression of HDAC8 or knocking down the histone acetyltransferase CREB-binding protein (CBP)/p300, known to target H3K27, rendered wild-type cells resistant to LeTx. As in RAW264.7 cells, primary bone marrow-derived macrophages exposed to a sub-lethal dose of LeTx were resistance to LeTx in an HDAC8-dependent manner. Collectively, this study demonstrates that epigenetic reprogramming mediated by HDAC8 plays a key role in determining the susceptibility of LeTx-induced pyroptosis in macrophages. PMID:24973453

  16. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    SciTech Connect

    Sharma, Bhupesh Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in

  17. Azorhodanine derivatives as inhibitors for acidic corrosion of nickel.

    PubMed

    Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Omar, Tark M

    2005-01-01

    Azorhodanine derivatives (HL1-HL5) were tested as corrosion inhibitors for nickel in 2M HNO3 solution using weight loss and galvanostatic polarization techniques. The results showed that these derivatives act as inhibitors for nickel in this medium. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. Polarization measurements indicated that these compounds act as mixed-type inhibitors, but the cathode is more polarized when an external current was applied. This means that these compounds retard the rate of hydrogen evolution and the rate of dissolution of the metal. Results showed that azorhodanine derivatives are adsorbed on the nickel surface following Temkin's adsorption isotherm. The activation energy and thermodynamic parameters were calculated and discussed at different temperatures (30-45 degrees C).

  18. Tcf1 and Lef1 transcription factors establish CD8(+) T cell identity through intrinsic HDAC activity.

    PubMed

    Xing, Shaojun; Li, Fengyin; Zeng, Zhouhao; Zhao, Yunjie; Yu, Shuyang; Shan, Qiang; Li, Yalan; Phillips, Farrah C; Maina, Peterson K; Qi, Hank H; Liu, Chengyu; Zhu, Jun; Pope, R Marshall; Musselman, Catherine A; Zeng, Chen; Peng, Weiqun; Xue, Hai-Hui

    2016-06-01

    The CD4(+) and CD8(+) T cell dichotomy is essential for effective cellular immunity. How individual T cell identity is established remains poorly understood. Here we show that the high-mobility group (HMG) transcription factors Tcf1 and Lef1 are essential for repressing CD4(+) lineage-associated genes including Cd4, Foxp3 and Rorc in CD8(+) T cells. Tcf1- and Lef1-deficient CD8(+) T cells exhibit histone hyperacetylation, which can be ascribed to intrinsic histone deacetylase (HDAC) activity in Tcf1 and Lef1. Mutation of five conserved amino acids in the Tcf1 HDAC domain diminishes HDAC activity and the ability to suppress CD4(+) lineage genes in CD8(+) T cells. These findings reveal that sequence-specific transcription factors can utilize intrinsic HDAC activity to guard cell identity by repressing lineage-inappropriate genes. PMID:27111144

  19. Development of imidazole alkanoic acids as mGAT3 selective GABA uptake inhibitors.

    PubMed

    Hack, Silke; Wörlein, Babette; Höfner, Georg; Pabel, Jörg; Wanner, Klaus T

    2011-05-01

    A new series of potential GABA uptake inhibitors starting from of 1H-imidazol-4-ylacetic acid with the carboxylic acid side chain originating from different positions and varying in length have been synthesized and tested for the inhibitory potency at the four GABA uptake transporters mGAT1-4 stably expressed in HEK cells. Further two bicyclic compounds with a rigidified carboxylic acid side chain were included in this study. The results of the biological tests indicated that most ω-imidazole alkanoic and alkenoic acid derivatives exhibit the highest potencies as GABA uptake inhibitors at mGAT3.

  20. Fam65b is important for formation of the HDAC6-dysferlin protein complex during myogenic cell differentiation.

    PubMed

    Balasubramanian, Anuradha; Kawahara, Genri; Gupta, Vandana A; Rozkalne, Anete; Beauvais, Ariane; Kunkel, Louis M; Gussoni, Emanuela

    2014-07-01

    Previously, we identified family with sequence similarity 65, member B (Fam65b), as a protein transiently up-regulated during differentiation and fusion of human myogenic cells. Silencing of Fam65b expression results in severe reduction of myogenin expression and consequent lack of myoblast fusion. The molecular function of Fam65b and whether misregulation of its expression could be causative of muscle diseases are unknown. Protein pulldowns were used to identify Fam65b-interacting proteins in differentiating human muscle cells and regenerating muscle tissue. In vitro, human muscle cells were treated with histone-deacetylase (HDAC) inhibitors, and expression of Fam65b and interacting proteins was studied. Nontreated cells were used as controls. In vivo, expression of Fam65b was down-regulated in developing zebrafish to determine the effects on muscle development. Fam65b binds to HDAC6 and dysferlin, the protein mutated in limb girdle muscular dystrophy 2B. The tricomplex Fam65b-HDAC6-dysferlin is transient, and Fam65b expression is necessary for the complex to form. Treatment of myogenic cells with pan-HDAC or HDAC6-specific inhibitors alters Fam65b expression, while dysferlin expression does not change. Inhibition of Fam65b expression in developing zebrafish results in abnormal muscle, with low birefringence, tears at the myosepta, and increased embryo lethality. Fam65b is an essential component of the HDAC6-dysferlin complex. Down-regulation of Fam65b in developing muscle causes changes consistent with muscle disease.-Balasubramanian, A., Kawahara, G., Gupta, V. A., Rozkalne, A., Beauvais, A., Kunkel, L. M., Gussoni, E. Fam65b is important for formation of the HDAC6-dysferlin protein complex during myogenic cell differentiation. PMID:24687993

  1. HISTONE DEACETYLASE 7 (HDAC7) REGULATES MYOCYTE MIGRATION AND DIFFERENTIATION

    PubMed Central

    Gao, Chengzhuo; Liu, Yu; Lam, Minh; Kao, Hung-Ying

    2010-01-01

    Summary Class IIa HDACs including HDAC7 play a role in gene expression, cell differentiation, and animal development through their association with transcription factors such as myogenic enhancer factors 2 (MEF2s). In this study, we show that endogenous HDAC7 localizes to both the nucleus and the cytoplasm of C2C12 myoblasts, but is exclusively retained in the cytoplasm of myotubes after completion of differentiation process. To elucidate the role of differential distribution of HDAC7 during myogenesis, we examined the effects of stably expressed HDAC7 mutants on myogenesis. Expression of nuclear-retained HDAC7 mutants significantly inhibits myogenesis in C2C12 cells and reduces the expression of muscle-specific myosin heavy chain (MHC) and myogenin. The inhibition in myocyte differentiation can be partially relieved by introduction of a mutation disrupting HDAC7:MEF2 interaction. Since phosphorylation of HDAC7 plays an important role in its nucleocytoplasmic shuttling, we further investigated the expression and distribution of phosphorylated HDAC7. To our surprise, the phosphorylation levels of HDAC7 at S344 and S479 were slightly decreased upon differentiation, whereas the phosphorylation of S178 was unchanged. Interestingly, a significant fraction of pS344- and/or pS479-HDAC7 localizes to plasma membrane of myotubes. In addition, Ser178-phosphorylated (pS178) HDAC7 shows a predominant actin filament-like staining prior to muscle differentiation and cytoplasmic and plasma membrane staining after differentiation. Consistent with this notion, HDAC7 partially co-localizes with actin filaments; in particular, pS178-HDAC7 largely colocalizes with actin filaments as indicated by phalloidin counter staining in myocytes. Furthermore, C2C12 cells expressing nuclear-retained HDAC7 display defects in migration. Our results provide novel insight into the mechanisms that regulate myocyte differentiation and migration by controlling the subcellular distribution of HDAC7 in

  2. Immunomodulatory effects of deacetylase inhibitors: therapeutic targeting of FOXP3+ regulatory T cells

    PubMed Central

    Wang, Liqing; de Zoeten, Edwin F.; Greene, Mark I.; Hancock, Wayne W.

    2010-01-01

    Classical zinc-dependent histone deacetylases (HDACs) catalyse the removal of acetyl groups from histone tails and also from many non-histone proteins, including the transcription factor FOXP3, a key regulator of the development and function of regulatory T cells. Many HDAC inhibitors are in cancer clinical trials, but a subset of HDAC inhibitors has important anti-inflammatory or immunosuppressive effects that might be of therapeutic benefit in immuno-inflammatory disorders or post-transplantation. At least some of these effects result from the ability of HDAC inhibitors to enhance the production and suppressive functions of FOXP3+ regulatory T cells. Understanding which HDACs contribute to the regulation of the functions of regulatory T cells may further stimulate the development of new class- or subclass-specific HDAC inhibitors with applications beyond oncology. PMID:19855427

  3. Class IIa HDACs repressive activities on MEF2-depedent transcription are associated with poor prognosis of ER⁺ breast tumors.

    PubMed

    Clocchiatti, Andrea; Di Giorgio, Eros; Ingrao, Sabrina; Meyer-Almes, Franz-Josef; Tripodo, Claudio; Brancolini, Claudio

    2013-03-01

    MEF2s transcription factors and class IIa HDACs compose a fundamental axis for several differentiation pathways. Functional relationships between this axis and cancer are largely unexplored. We have found that class IIa HDACs are heterogeneously expressed and display redundant activities in breast cancer cells. Applying gene set enrichment analysis to compare the expression profile of a list of putative MEF2 target genes, we have discovered a correlation between the down-regulation of the MEF2 signature and the aggressiveness of ER(+) breast tumors. Kaplan-Meier analysis in ER(+) breast tumors evidenced an association between increased class IIa HDACs expression and reduced survival. The important role of the MEF2-HDAC axis in ER(+) breast cancer was confirmed in cultured cells. MCF7 ER(+) cells were susceptible to silencing of class IIa HDACs in terms of both MEF2-dependent transcription and apoptosis. Conversely, in ER(-) MDA-MB-231 cells, the repressive influence of class IIa HDACs was dispensable. Similarly, a class IIa HDAC-specific inhibitor preferentially promoted the up-regulation of several MEF2 target genes and apoptosis in ER(+) cell lines. The prosurvival function of class IIa HDACs could be explained by the repression of NR4A1/Nur77, a proapoptotic MEF2 target. In summary, our studies underscore a contribution of class IIa HDACs to aggressiveness of ER(+) tumors.-Clocchiatti, A., Di Giorgio, E., Ingrao, S., Meyer-Almes, F.-J., Tripodo, C., Brancolini, C. Class IIa HDACs repressive activities on MEF2-depedent transcription are associated with poor prognosis of ER(+) breast tumors.

  4. Ginsenoside Rg3 Inhibits Melanoma Cell Proliferation through Down-Regulation of Histone Deacetylase 3 (HDAC3) and Increase of p53 Acetylation

    PubMed Central

    Shan, Xiu; Fu, Yuan-Shan; Aziz, Faisal; Wang, Xiao-Qi; Yan, Qiu; Liu, Ji-Wei

    2014-01-01

    Malignant melanoma is an aggressive and deadly form of skin cancer, and despite recent advances in available therapies, is still lacking in completely effective treatments. Rg3, a monomer extracted from ginseng roots, has been attempted for the treatment of many cancers. It is reported that the expressions of histone deacetylase 3 (HDAC3) and p53 acetylation correlate with tumor cell growth. However, the antitumor effect of Rg3 on melanoma and the mechanism by which it regulates HDAC3 expression and p53 acetylation remain unknown. We found high expression of HDAC3 in human melanoma tissues to be significantly correlated to lymph node metastasis and clinical stage of disease (p<0.05). In melanoma cells, Rg3 inhibited cell proliferation and induced G0/G1 cell cycle arrest. Rg3 also decreased the expression of HDAC3 and increased the acetylation of p53 on lysine (k373/k382). Moreover, suppression of HDAC3 by either siRNA or a potent HDAC3 inhibitor (MS-275) inhibited cell proliferation, increased p53 acetylation and transcription activity. In A375 melanoma xenograft studies, we demonstrated that Rg3 and HDAC3 short hairpin RNA (shHDAC3) inhibited the growth of xenograft tumors with down-regulation of HDAC3 expression and up-regulation of p53 acetylation. In conclusion, Rg3 has antiproliferative activity against melanoma by decreasing HDAC3 and increasing acetylation of p53 both in vitro and in vivo. Thus, Rg3 serves as a potential therapeutic agent for the treatment of melanoma. PMID:25521755

  5. Synthesis, modelling and kinetic assays of potent inhibitors of purple acid phosphatase.

    PubMed

    Mohd-Pahmi, Siti Hajar; Hussein, Waleed M; Schenk, Gerhard; McGeary, Ross P

    2011-05-15

    Purple acid phosphatases (PAPs) are binuclear metallohydrolases that have been isolated from various mammals, plants, fungi and bacteria. In mammals PAP activity is associated with bone resorption and can lead to bone metabolic disorders such as osteoporosis; thus human PAP is an attractive target to develop anti-osteoporotic drugs. Based on a previous lead compound and rational drug design, acyl derivatives of α-aminonaphthylmethylphosphonic acid were synthesised and tested as PAP inhibitors. Kinetic analysis showed that they are good PAP inhibitors whose potencies improve with increasing acyl chain length. Maximum potency is reached when the number of carbons in the acyl chain is between 12 and 14. The most potent inhibitor of red kidney bean PAP is the dodecyl-derivative with K(ic)=5 μM, while the most potent pig PAP inhibitor is the tetradecyl-derivative with K(ic)=8 μM, the most potent inhibitor of a mammalian PAP yet reported.

  6. Signal-dependent repression of DUSP5 by class I HDACs controls nuclear ERK activity and cardiomyocyte hypertrophy.

    PubMed

    Ferguson, Bradley S; Harrison, Brooke C; Jeong, Mark Y; Reid, Brian G; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; McKinsey, Timothy A

    2013-06-11

    Cardiac hypertrophy is a strong predictor of morbidity and mortality in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors have been shown to suppress cardiac hypertrophy through mechanisms that remain poorly understood. We report that class I HDACs function as signal-dependent repressors of cardiac hypertrophy via inhibition of the gene encoding dual-specificity phosphatase 5 (DUSP5) DUSP5, a nuclear phosphatase that negatively regulates prohypertrophic signaling by ERK1/2. Inhibition of DUSP5 by class I HDACs requires activity of the ERK kinase, mitogen-activated protein kinase kinase (MEK), revealing a self-reinforcing mechanism for promotion of cardiac ERK signaling. In cardiac myocytes treated with highly selective class I HDAC inhibitors, nuclear ERK1/2 signaling is suppressed in a manner that is absolutely dependent on DUSP5. In contrast, cytosolic ERK1/2 activation is maintained under these same conditions. Ectopic expression of DUSP5 in cardiomyocytes results in potent inhibition of agonist-dependent hypertrophy through a mechanism involving suppression of the gene program for hypertrophic growth. These findings define unique roles for class I HDACs and DUSP5 as integral components of a regulatory signaling circuit that controls cardiac hypertrophy.

  7. A single allele of Hdac2 but not Hdac1 is sufficient for normal mouse brain development in the absence of its paralog

    PubMed Central

    Krahmer, Julia; Leopoldi, Alexandra; Artaker, Matthias; Pusch, Oliver; Zezula, Jürgen; Weissmann, Simon; Xie, Yunli; Schöfer, Christian; Schlederer, Michaela; Brosch, Gerald; Matthias, Patrick; Selfridge, Jim; Lassmann, Hans; Knoblich, Jürgen A.; Seiser, Christian

    2016-01-01

    The histone deacetylases HDAC1 and HDAC2 are crucial regulators of chromatin structure and gene expression, thereby controlling important developmental processes. In the mouse brain, HDAC1 and HDAC2 exhibit different developmental stage- and lineage-specific expression patterns. To examine the individual contribution of these deacetylases during brain development, we deleted different combinations of Hdac1 and Hdac2 alleles in neural cells. Ablation of Hdac1 or Hdac2 by Nestin-Cre had no obvious consequences on brain development and architecture owing to compensation by the paralog. By contrast, combined deletion of Hdac1 and Hdac2 resulted in impaired chromatin structure, DNA damage, apoptosis and embryonic lethality. To dissect the individual roles of HDAC1 and HDAC2, we expressed single alleles of either Hdac1 or Hdac2 in the absence of the respective paralog in neural cells. The DNA-damage phenotype observed in double knockout brains was prevented by expression of a single allele of either Hdac1 or Hdac2. Strikingly, Hdac1−/−Hdac2+/− brains showed normal development and no obvious phenotype, whereas Hdac1+/−Hdac2−/− mice displayed impaired brain development and perinatal lethality. Hdac1+/−Hdac2−/− neural precursor cells showed reduced proliferation and premature differentiation mediated by overexpression of protein kinase C, delta, which is a direct target of HDAC2. Importantly, chemical inhibition or knockdown of protein kinase C delta was sufficient to rescue the phenotype of neural progenitor cells in vitro. Our data indicate that HDAC1 and HDAC2 have a common function in maintaining proper chromatin structures and show that HDAC2 has a unique role by controlling the fate of neural progenitors during normal brain development. PMID:24449838

  8. Role of HDACs in optic nerve damage-induced nuclear atrophy of retinal ganglion cells.

    PubMed

    Schmitt, Heather M; Schlamp, Cassandra L; Nickells, Robert W

    2016-06-20

    Optic neuropathies are characterized by retinal ganglion cell (RGC) death, resulting in the loss of vision. In glaucoma, the most common optic neuropathy, RGC death is initiated by axonal damage, and can be modeled by inducing acute axonal trauma through procedures such as optic nerve crush (ONC) or optic nerve axotomy. One of the early events of RGC death is nuclear atrophy, and is comprised of RGC-specific gene silencing, histone deacetylation, heterochromatin formation, and nuclear shrinkage. These early events appear to be principally regulated by epigenetic mechanisms involving histone deacetylation. Class I histone deacetylases HDACs 1, 2, and 3 are known to play important roles in the process of early nuclear atrophy in RGCs, and studies using both inhibitors and genetic ablation of Hdacs also reveal a critical role in the cell death process. Select inhibitors, such as those being developed for cancer therapy, may also provide a viable secondary treatment option for optic neuropathies.

  9. 2-Aminoimidazole Amino Acids as Inhibitors of the Binuclear Manganese Metalloenzyme Human Arginase I

    SciTech Connect

    Ilies, M.; Di Costanzo, L; North, M; Scott, J; Christianson, D

    2010-01-01

    Arginase, a key metalloenzyme of the urea cycle that converts L-arginine into L-ornithine and urea, is presently considered a pharmaceutical target for the management of diseases associated with aberrant L-arginine homeostasis, such as asthma, cardiovascular diseases, and erectile dysfunction. We now report the design, synthesis, and evaluation of a series of 2-aminoimidazole amino acid inhibitors in which the 2-aminoimidazole moiety serves as a guanidine mimetic. These compounds represent a new class of arginase inhibitors. The most potent inhibitor identified in this study, 2-(S)-amino-5-(2-aminoimidazol-1-yl)pentanoic acid (A1P, 10), binds to human arginase I with K{sub d} = 2 {micro}M and significantly attenuates airways hyperresponsiveness in a murine model of allergic airways inflammation. These findings suggest that 2-aminoimidazole amino acids represent new leads for the development of arginase inhibitors with promising pharmacological profiles.

  10. Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants.

    PubMed

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

    Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes, but their therapeutic use remains limited because of various adverse effects. Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD). Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD. Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors). In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors' therapeutic potential. MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2. In the hypothalamic-pituitary-adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted. PMID:26630956

  11. Holocarboxylase synthetase acts as a biotin-independent transcriptional repressor interacting with HDAC1, HDAC2 and HDAC7.

    PubMed

    Trujillo-Gonzalez, Isis; Cervantes-Roldan, Rafael; Gonzalez-Noriega, Alfonso; Michalak, Colette; Reyes-Carmona, Sandra; Barrios-Garcia, Tonatiuh; Meneses-Morales, Ivan; Leon-Del-Rio, Alfonso

    2014-03-01

    In human cells, HCS catalyzes the biotinylation of biotin-dependent carboxylases and mediates the transcriptional control of genes involved in biotin metabolism through the activation of a cGMP-dependent signal transduction pathway. HCS also targets to the cell nucleus in association with lamin-B suggesting additional gene regulatory functions. Studies from our laboratory in Drosophila melanogaster showed that nuclear HCS is associated with heterochromatin bands enriched with the transcriptionally repressive mark histone 3 trimethylated at lysine 9. Further, HCS was shown to be recruited to the core promoter of the transcriptionally inactive hsp70 gene suggesting that it may participate in the repression of gene expression, although the mechanism involved remained elusive. In this work, we expressed HCS as a fusion protein with the DNA-binding domain of GAL4 to evaluate its effect on the transcription of a luciferase reporter gene. We show that HCS possesses transcriptional repressor activity in HepG2 cells. The transcriptional function of HCS was shown by in vitro pull down and in vivo co-immunoprecipitation assays to depend on its interaction with the histone deacetylases HDAC1, HDAC2 and HDAC7. We show further that HCS interaction with HDACs and its function in transcriptional repression is not affected by mutations impairing its biotin-ligase activity. We propose that nuclear HCS mediates events of transcriptional repression through a biotin-independent mechanism that involves its interaction with chromatin-modifying protein complexes that include histone deacetylases.

  12. Specific HDAC6 inhibition by ACY-738 reduces SLE pathogenesis in NZB/W mice.

    PubMed

    Regna, Nicole L; Vieson, Miranda D; Luo, Xin M; Chafin, Cristen B; Puthiyaveetil, Abdul Gafoor; Hammond, Sarah E; Caudell, David L; Jarpe, Matthew B; Reilly, Christopher M

    2016-01-01

    We sought to determine if a selective HDAC6 inhibitor (ACY-738) decreases disease in NZB/W mice. From 22 to 38weeks-of-age, mice were injected intraperitoneally with 5 or 20mg/kg of ACY-738, or vehicle control. Body weight and proteinuria were measured every 2weeks, while sera anti-dsDNA, Ig isotypes, and cytokine levels were measured every 4weeks. Kidney disease was determined by evaluation of sera, urine, immune complex deposition, and renal pathology. Flow cytometric analysis assessed thymic, splenic, bone marrow, and peripheral lymphocyte differentiation patterns. Our results showed HDAC6 inhibition decreased SLE disease by inhibiting immune complex-mediated glomerulonephritis, sera anti-dsDNA levels, and inflammatory cytokine production and increasing splenic Treg cells. Inhibition of HDAC6 increased the percentage of cells in the early-stage developmental fractions of both pro- and pre-B cells. These results suggest that specific HDAC6 inhibition may be able to decrease SLE disease by altering aberrant T and B cell differentiation. PMID:26604012

  13. 4-Biphenylalanine- and 3-Phenyltyrosine-Derived Hydroxamic Acids as Inhibitors of the JumonjiC-Domain-Containing Histone Demethylase KDM4A.

    PubMed

    Morera, Ludovica; Roatsch, Martin; Fürst, Michael C D; Hoffmann, Inga; Senger, Johanna; Hau, Mirjam; Franz, Henriette; Schüle, Roland; Heinrich, Markus R; Jung, Manfred

    2016-09-20

    Overexpression of the histone lysine demethylase KDM4A, which regulates H3K9 and H3K36 methylation states, has been related to the pathology of several human cancers. We found that a previously reported hydroxamate-based histone deacetylase (HDAC) inhibitor (SW55) was also able to weakly inhibit this demethylase with an IC50 value of 25.4 μm. Herein we report the synthesis and biochemical evaluations, with two orthogonal in vitro assays, of a series of derivatives of this lead structure. With extensive chemical modifications on the lead structure, also by exploiting the versatility of the radical arylation with aryldiazonium salts, we were able to increase the potency of the derivatives against KDM4A to the low-micromolar range and, more importantly, to obtain demethylase selectivity with respect to HDACs. Cell-permeable derivatives clearly showed a demethylase-inhibition-dependent antiproliferative effect against HL-60 human promyelocytic leukemia cells.

  14. Synthesis and antibacterial evaluation of anziaic acid and analogues as topoisomerase I inhibitors

    PubMed Central

    Lin, Hao; Annamalai, Thirunavukkarasu; Bansod, Priyanka; Tse-Dinh, Yuk-Ching

    2013-01-01

    Naturally occurring anziaic acid was very recently reported as a topoisomerase I inhibitor with antibacterial activity. Herein total synthesis of anziaic acid and structural analogues is described and the preliminary structure-activity relationship (SAR) has been developed based on topoisomerase inhibition and whole cell antibacterial activity. PMID:24363888

  15. 4-Quinolone-3-carboxylic acids as cell-permeable inhibitors of protein tyrosine phosphatase 1B.

    PubMed

    Zhi, Ying; Gao, Li-Xin; Jin, Yi; Tang, Chun-Lan; Li, Jing-Ya; Li, Jia; Long, Ya-Qiu

    2014-07-15

    Protein tyrosine phosphatase 1B is a negative regulator in the insulin and leptin signaling pathways, and has emerged as an attractive target for the treatment of type 2 diabetes and obesity. However, the essential pharmacophore of charged phosphotyrosine or its mimetic confer low selectivity and poor cell permeability. Starting from our previously reported aryl diketoacid-based PTP1B inhibitors, a drug-like scaffold of 4-quinolone-3-carboxylic acid was introduced for the first time as a novel surrogate of phosphotyrosine. An optimal combination of hydrophobic groups installed at C-6, N-1 and C-3 positions of the quinolone motif afforded potent PTP1B inhibitors with low micromolar IC50 values. These 4-quinolone-3-carboxylate based PTP1B inhibitors displayed a 2-10 fold selectivity over a panel of PTP's. Furthermore, the bidentate inhibitors of 4-quinolone-3-carboxylic acids conjugated with aryl diketoacid or salicylic acid were cell permeable and enhanced insulin signaling in CHO/hIR cells. The kinetic studies and molecular modeling suggest that the 4-quinolone-3-carboxylates act as competitive inhibitors by binding to the PTP1B active site in the WPD loop closed conformation. Taken together, our study shows that the 4-quinolone-3-carboxylic acid derivatives exhibit improved pharmacological properties over previously described PTB1B inhibitors and warrant further preclinical studies.

  16. Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants

    PubMed Central

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

    Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes, but their therapeutic use remains limited because of various adverse effects. Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD). Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD. Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors). In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors’ therapeutic potential. MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2. In the hypothalamic–pituitary–adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted. PMID:26630956

  17. Physiological Roles of Class I HDAC Complex and Histone Demethylase

    PubMed Central

    Hayakawa, Tomohiro; Nakayama, Jun-ichi

    2011-01-01

    Epigenetic gene silencing is one of the fundamental mechanisms for ensuring proper gene expression patterns during cellular differentiation and development. Histone deacetylases (HDACs) are evolutionally conserved enzymes that remove acetyl modifications from histones and play a central role in epigenetic gene silencing. In cells, HDAC forms a multiprotein complex (HDAC complex) in which the associated proteins are believed to help HDAC carry out its cellular functions. Though each HDAC complex contains distinct components, the presence of isoforms for some of the components expands the variety of complexes and the diversity of their cellular roles. Recent studies have also revealed a functional link between HDAC complexes and specific histone demethylases. In this paper, we summarize the distinct and cooperative roles of four class I HDAC complexes, Sin3, NuRD, CoREST, and NCoR/SMRT, with respect to their component diversity and their relationship with specific histone demethylases. PMID:21049000

  18. Inhibitors

    MedlinePlus

    ... Community Counts Blood Safety Inhibitors Articles & Key Findings Free Materials Videos Starting the Conversation Playing it Safe A Look at Hemophilia Joint Range of Motion My Story Links to Other Websites ...

  19. Lichen secondary metabolite evernic acid as potential quorum sensing inhibitor against Pseudomonas aeruginosa.

    PubMed

    Gökalsın, Barış; Sesal, Nüzhet Cenk

    2016-09-01

    Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential. Lichens have ethnobotanical value for their medicinal properties and it is possible that their secondary metabolites have quorum sensing inhibitor properties. This study aims to investigate an alternative treatment approach by utilizing lichen secondary metabolite evernic acid to reduce the expressions of Pseudomonas aeruginosa virulence factors by inhibiting quorum sensing. For this purpose, fluorescent monitor strains were utilized for quorum sensing inhibitor screens and quantitative reverse-transcriptase PCR analyses were conducted for comparison. Results indicate that evernic acid is capable of inhibiting Pseudomonas aeruginosa quorum sensing systems.

  20. Identification of small molecule sulfonic acids as ecto-5'-Nucleotidase inhibitors.

    PubMed

    Raza, Rabia; Saeed, Aamer; Lecka, Joanna; Sévigny, Jean; Iqbal, Jamshed

    2012-11-01

    Ecto-5'-Nucleotidase inhibitors have great potential as anti-tumor agents. We have investigated biochemical properties of human and rat ecto-5'-Nucleotidases and characterized 19 small molecule sulfonic acid derivatives as potential inhibitors of ecto-5'-Nucleotidases. We identified 11 potent inhibitors of human and rat ecto-5'-Nucleotidases and checked their selectivity. Compound 10 (Sodium 2,4-dinitrobenzenesulfonate) with K(i) value of 0.66 μM and 19 (N-(4-sulfamoylphenylcarbamothioyl) pivalamide) with K(i) value of 0.78 μM were identified as the most potent inhibitors for human and rat ecto-5'-Nucleotidase, respectively. The present compounds have low molecular weights, water solubility and equal potency as compared to the reported inhibitors.

  1. Synthesis of potent inhibitors of anthrax toxin based on poly-L-glutamic acid.

    PubMed

    Joshi, Amit; Saraph, Arundhati; Poon, Vincent; Mogridge, Jeremy; Kane, Ravi S

    2006-01-01

    We report the synthesis of biodegradable polyvalent inhibitors of anthrax toxin based on poly-L-glutamic acid (PLGA). These biocompatible polyvalent inhibitors are at least 4 orders of magnitude more potent than the corresponding monovalent peptides in vitro and are comparable in potency to polyacrylamide-based inhibitors of anthrax toxin assembly. We have elucidated the influence of peptide density on inhibitory potency and demonstrated that these inhibitory potencies are limited by kinetics, with even higher activities seen when the inhibitors are preincubated with the heptameric receptor-binding subunit of anthrax toxin prior to exposure to cells. These polyvalent inhibitors are also effective at neutralizing anthrax toxin in vivo and represent attractive leads for designing biocompatible anthrax therapeutics.

  2. Synthesis of potent inhibitors of anthrax toxin based on poly-L-glutamic acid.

    PubMed

    Joshi, Amit; Saraph, Arundhati; Poon, Vincent; Mogridge, Jeremy; Kane, Ravi S

    2006-01-01

    We report the synthesis of biodegradable polyvalent inhibitors of anthrax toxin based on poly-L-glutamic acid (PLGA). These biocompatible polyvalent inhibitors are at least 4 orders of magnitude more potent than the corresponding monovalent peptides in vitro and are comparable in potency to polyacrylamide-based inhibitors of anthrax toxin assembly. We have elucidated the influence of peptide density on inhibitory potency and demonstrated that these inhibitory potencies are limited by kinetics, with even higher activities seen when the inhibitors are preincubated with the heptameric receptor-binding subunit of anthrax toxin prior to exposure to cells. These polyvalent inhibitors are also effective at neutralizing anthrax toxin in vivo and represent attractive leads for designing biocompatible anthrax therapeutics. PMID:16984137

  3. Histone deacetylase inhibitors as cancer therapeutics.

    PubMed

    Clawson, Gary A

    2016-08-01

    Cancer cells contain significant alterations in their epigenomic landscape, which several enzyme families reversibly contribute to. One class of epigenetic modifying enzymes is that of histone deacetylases (HDAC), which are receiving considerable scrutiny clinically as a therapeutic target in many cancers. The underlying rationale is that inhibiting HDACs will reverse dysregulated target gene expression by modulating functional histone (or other) acetylation marks. This perspective will discuss a recent paper by Markozashvili and co-workers which appeared in Gene, which indicates that the mechanisms by which HDAC inhibitors (HDACis) alter the epigenetic landscape include widespread alternative effects beyond simply controlling regional epigenetic marks. HDACs are involved in many processes/diseases, and it is not surprising that HDACis have considerable off-target effects, and thus a major effort is being directed toward identification of inhibitors which are selective for HDAC isoforms often uniquely implicated in various cancers. This Perspective will also discuss some representative work with inhibitors targeting individual HDAC classes or isoforms. At present, it is not really clear that isoform-specific HDACis will avoid non-selective effects on other unrecognized activities of HDACs. PMID:27568481

  4. Histone deacetylase inhibitors as cancer therapeutics

    PubMed Central

    2016-01-01

    Cancer cells contain significant alterations in their epigenomic landscape, which several enzyme families reversibly contribute to. One class of epigenetic modifying enzymes is that of histone deacetylases (HDAC), which are receiving considerable scrutiny clinically as a therapeutic target in many cancers. The underlying rationale is that inhibiting HDACs will reverse dysregulated target gene expression by modulating functional histone (or other) acetylation marks. This perspective will discuss a recent paper by Markozashvili and co-workers which appeared in Gene, which indicates that the mechanisms by which HDAC inhibitors (HDACis) alter the epigenetic landscape include widespread alternative effects beyond simply controlling regional epigenetic marks. HDACs are involved in many processes/diseases, and it is not surprising that HDACis have considerable off-target effects, and thus a major effort is being directed toward identification of inhibitors which are selective for HDAC isoforms often uniquely implicated in various cancers. This Perspective will also discuss some representative work with inhibitors targeting individual HDAC classes or isoforms. At present, it is not really clear that isoform-specific HDACis will avoid non-selective effects on other unrecognized activities of HDACs. PMID:27568481

  5. HDAC3-dependent reversible lysine acetylation of cardiac myosin heavy chain isoforms modulates their enzymatic and motor activity.

    PubMed

    Samant, Sadhana A; Courson, David S; Sundaresan, Nagalingam R; Pillai, Vinodkumar B; Tan, Minjia; Zhao, Yingming; Shroff, Sanjeev G; Rock, Ronald S; Gupta, Mahesh P

    2011-02-18

    Reversible lysine acetylation is a widespread post-translational modification controlling the activity of proteins in different subcellular compartments. We previously demonstrated that a class II histone deacetylase (HDAC), HDAC4, and a histone acetyltransferase, PCAF, associate with cardiac sarcomeres, and a class I and II HDAC inhibitor, trichostatin A, enhances contractile activity of myofilaments. In this study, we show that a class I HDAC, HDAC3, is also present at cardiac sarcomeres. By immunohistochemical and electron microscopic analyses, we found that HDAC3 was localized to the A band of sarcomeres and was capable of deacetylating myosin heavy chain (MHC) isoforms. The motor domains of both cardiac α- and β-MHC isoforms were found to be reversibly acetylated. Biomechanical studies revealed that lysine acetylation significantly decreased the K(m) for the actin-activated ATPase activity of both α- and β-MHC isoforms. By an in vitro motility assay, we found that lysine acetylation increased the actin sliding velocity of α-myosin by 20% and β-myosin by 36%, compared to their respective non-acetylated isoforms. Moreover, myosin acetylation was found to be sensitive to cardiac stress. During induction of hypertrophy, myosin isoform acetylation increased progressively with duration of stress stimuli, independent of isoform shift, suggesting that lysine acetylation of myosin could be an early response of myofilaments to increase contractile performance of the heart. These studies provide the first evidence for localization of HDAC3 at myofilaments and uncover a novel mechanism modulating the motor activity of cardiac MHC isoforms.

  6. Histone deacetylase 9 regulates breast cancer cell proliferation and the response to histone deacetylase inhibitors

    PubMed Central

    Lapierre, Marion; Linares, Aurélien; Dalvai, Mathieu; Duraffourd, Céline; Bonnet, Sandrine; Boulahtouf, Abdelhay; Rodriguez, Carmen; Jalaguier, Stéphan; Assou, Said; Orsetti, Beatrice; Balaguer, Patrick; Maudelonde, Thierry; Blache, Philippe; Bystricky, Kerstin; Boulle, Nathalie; Cavaillès, Vincent

    2016-01-01

    Histone lysine acetylation is an epigenetic mark regulated by histone acetyltransferases and histone deacetylases (HDAC) which plays an important role in tumorigenesis. In this study, we observed a strong overexpression of class IIa HDAC9, at the mRNA and protein levels, in the most aggressive human breast cancer cell lines (i.e. in basal breast cancer cells vs luminal ones or in malignant vs begnin MCF10A breast epithelial cell lines). HDAC9 overexpression was associated with higher rates of gene transcription and increased epigenetic marks on the HDAC9 promoter. Ectopic expression of HDAC9 in MCF7 luminal breast cancer cells led to an increase in cell proliferation and to a decrease in apoptosis. These effects were associated with a deregulated expression of several genes controlled by HDAC inhibitors such as CDKN1A, BAX and TNFRSF10A. Inversely, knock-down of HDAC9 expression in MDA-MB436 basal breast cancer cells reduced cell proliferation. Moreover, high HDAC9 expression decreased the efficacy of HDAC inhibitors to reduce cell proliferation and to regulate CDKN1A gene expression. Interestingly, the gene encoding the transcription factor SOX9 was identified by a global transcriptomic approach as an HDAC9 target gene. In stably transfected MCF7 cells, SOX9 silencing significantly decreased HDAC9 mitogenic activity. Finally, in a large panel of breast cancer biopsies, HDAC9 expression was significantly increased in tumors of the basal subtype, correlated with SOX9 expression and associated with poor prognosis. Altogether, these results indicate that HDAC9 is a key factor involved in mammary carcinogenesis and in the response to HDAC inhibitors. PMID:26930713

  7. Natural fatty acid synthase inhibitors as potent therapeutic agents for cancers: A review.

    PubMed

    Zhang, Jia-Sui; Lei, Jie-Ping; Wei, Guo-Qing; Chen, Hui; Ma, Chao-Ying; Jiang, He-Zhong

    2016-09-01

    Context Fatty acid synthase (FAS) is the only mammalian enzyme to catalyse the synthesis of fatty acid. The expression level of FAS is related to cancer progression, aggressiveness and metastasis. In recent years, research on natural FAS inhibitors with significant bioactivities and low side effects has increasingly become a new trend. Herein, we present recent research progress on natural fatty acid synthase inhibitors as potent therapeutic agents. Objective This paper is a mini overview of the typical natural FAS inhibitors and their possible mechanism of action in the past 10 years (2004-2014). Method The information was collected and compiled through major databases including Web of Science, PubMed, and CNKI. Results Many natural products induce cancer cells apoptosis by inhibiting FAS expression, with fewer side effects than synthetic inhibitors. Conclusion Natural FAS inhibitors are widely distributed in plants (especially in herbs and foods). Some natural products (mainly phenolics) possessing potent biological activities and stable structures are available as lead compounds to synthesise promising FAS inhibitors.

  8. A crystallographic fragment screen identifies cinnamic acid derivatives as starting points for potent Pim-1 inhibitors.

    PubMed

    Schulz, Michèle N; Fanghänel, Jörg; Schäfer, Martina; Badock, Volker; Briem, Hans; Boemer, Ulf; Nguyen, Duy; Husemann, Manfred; Hillig, Roman C

    2011-03-01

    A crystallographic fragment screen was carried out to identify starting points for the development of inhibitors of protein kinase Pim-1, a potential target for tumour therapy. All fragment hits identified via soaking in this study turned out to bind to the unusually hydrophobic pocket at the hinge region. The most potent fragments, two cinnamic acid derivatives (with a best IC(50) of 130 µM), additionally form a well defined hydrogen bond. The balance between hydrophobic and polar interactions makes these molecules good starting points for further optimization. Pim-2 inhibitors from a recently reported high-throughput screening campaign also feature a cinnamic acid moiety. Two of these Pim-2 inhibitors were synthesized, their potencies against Pim-1 were determined and their cocrystal structures were elucidated in order to determine to what degree the binding modes identified by fragment screening are conserved in optimized inhibitors. The structures show that the cinnamic acid moieties indeed adopt the same binding mode. Fragment screening thus correctly identified binding modes which are maintained when fragments are grown into larger and higher affinity inhibitors. The high-throughput screening-derived compound (E)-3-{3-[6-(4-aminocyclohexylamino)-pyrazin-2-yl]phenyl}acrylic acid (compound 1) is the most potent inhibitor of the cinnamic acid series for which the three-dimensional binding mode is known (IC(50) = 17 nM, K(d) = 28 nM). The structure reveals the molecular basis for the large gain in potency between the initial fragment hit and this optimized inhibitor.

  9. Sp3/REST/HDAC1/HDAC2 Complex Represses and Sp1/HIF-1/p300 Complex Activates ncx1 Gene Transcription, in Brain Ischemia and in Ischemic Brain Preconditioning, by Epigenetic Mechanism.

    PubMed

    Formisano, Luigi; Guida, Natascia; Valsecchi, Valeria; Cantile, Maria; Cuomo, Ornella; Vinciguerra, Antonio; Laudati, Giusy; Pignataro, Giuseppe; Sirabella, Rossana; Di Renzo, Gianfranco; Annunziato, Lucio

    2015-05-13

    The Na(+)-Ca(2+) exchanger 1 (NCX1) is reduced in stroke by the RE1-silencing transcription factor (REST), whereas it is increased in ischemic brain preconditioning (PC) by hypoxia-inducible factor 1 (HIF-1). Because ncx1 brain promoter (ncx1-Br) has five putative consensus sequences, named Sp1A-E, for the specificity protein (Sp) family of transcription factors (Sp1-4), we investigated the role of this family in regulating ncx1 transcription in rat cortical neurons. Here we found that Sp1 is a transcriptional activator, whereas Sp3 is a transcriptional repressor of ncx1, and that both bind ncx1-Br in a sequence-specific manner, modulating ncx1 transcription through the Sp1 sites C-E. Furthermore, by transient middle cerebral artery occlusion (tMCAO) in rats, the transcriptional repressors Sp3 and REST colocalized with the two histone-deacetylases (HDACs) HDAC1 and HDAC2 on the ncx1-Br, with a consequent hypoacetylation. Contrarily, in PC+tMCAO the transcriptional activators Sp1 and HIF-1 colocalized with histone acetyltransferase p300 on ncx1-Br with a consequent hyperacetylation. In addition, in neurons silenced with siRNA of NCX1 and subjected to oxygen and glucose deprivation (OGD) (3 h) plus reoxygenation (RX) (24 h), the neuroprotection of Class I HDAC inhibitor MS-275 was counteracted, whereas in neurons overexpressing NCX1 and subjected to ischemic preconditioning (PC+OGD/RX), the neurotoxic effect of p300 inhibitor C646 was prevented. Collectively, these results demonstrate that NCX1 expression is regulated by the Sp3/REST/HDAC1/HDAC2 complex in tMCAO and by the Sp1/HIF-1/p300 complex in PC+tMCAO and that epigenetic intervention, by modulating the acetylation of ncx1-Br, may be a strategy for the development of innovative therapeutic intervention in stroke. PMID:25972164

  10. Inhibitors of fatty acid biosynthesis in sunflower seeds.

    PubMed

    Pleite, Rafael; Martínez-Force, Enrique; Garcés, Rafael

    2006-09-01

    During de novo fatty acid synthesis in sunflower seeds, saturated fatty acid production is influenced by the competition between the enzymes of the principal pathways and the saturated acyl-ACP thioesterases. Genetic backgrounds with more efficient saturated acyl-ACP thioesterase alleles only express their phenotypic effects when the alleles for the enzymes in the main pathway are less efficient. For this reason, we studied the incorporation of [2-(14)C]acetate into the lipids of developing sunflower seeds (Helianthus annuus L.) from several mutant lines in vivo. The labelling of different triacylglycerol fatty acids in different oilseed mutants reflects the fatty acid composition of the seed and supports the channelling theory of fatty acid biosynthesis. Incubation with methyl viologen diminished the conversion of stearoyl-ACP to oleoyl-ACP in vivo through a decrease in the available reductant power. In turn, this led to the accumulation of stearoyl-ACP to the levels detected in seeds from high stearic acid mutants. The concomitant reduction of oleoyl-ACP content inside the plastid allowed us to study the activity of acyl-ACP thioesterases on saturated fatty acids. In these mutants, we verified that the accumulation of saturated fatty acids requires efficient thioesterase activity on saturated-ACPs. By studying the effects of cerulenin on the in vivo incorporation of [2-(14)C]acetate into lipids and on the in vitro activity of beta-ketoacyl-ACP synthase II, we found that elongation to very long chain fatty acids can occur both inside and outside of the plastid in sunflower seeds. PMID:16500723

  11. Synthesis and evaluation of new omega-borono-alpha-amino acids as rat liver arginase inhibitors.

    PubMed

    Busnel, Olivier; Carreaux, François; Carboni, Bertrand; Pethe, Stephanie; Goff, Sandrine Vadon-Le; Mansuy, Daniel; Boucher, Jean-Luc

    2005-04-01

    Recent studies have demonstrated that arginase plays important roles in pathologies such as asthma or erectile dysfunctions. We have synthesized new omega-borono-alpha-amino acids that are analogues of the previously known arginase inhibitors S-(2-boronoethyl)-l-cysteine (BEC) and 2-amino-6-boronohexanoic acid (ABH) and evaluated them as inhibitors of purified rat liver arginase (RLA). In addition to the distance between the B(OH)(2) and the alpha-amino acid functions, the position of the sulfur atom in the side chain also appears as a key determinant for the interaction with the active site of RLA. Furthermore, substitution of the alkyl side chain of BEC by methyl groups and conformational restriction of ABH by incorporation of its side chain in a phenyl ring led to inactive compounds. These results suggest that subtle interactions govern the affinity of inhibitors for the active site of RLA.

  12. Optimization of amino acid thioesters as inhibitors of metallo-β-lactamase L1.

    PubMed

    Liu, Xiao-Long; Yang, Ke-Wu; Zhang, Yue-Juan; Ge, Ying; Xiang, Yang; Chang, Ya-Nan; Oelschlaeger, Peter

    2016-10-01

    The emergence of antibiotic resistance caused by metallo-β-lactamases (MβLs) is a global public health problem. Recently, we found amino acid thioesters to be a highly promising scaffold for inhibitors of the MβL L1. In order to optimize this series of inhibitors, nine new amino acid thioesters were developed by modifying the substituents on the N-terminus of the thioesters and the groups representing the amino acid side chain. Biological activity assays indicate that all of them are very potent inhibitors of L1 with an IC50 value range of 20-600nM, lower than those of most of the previously reported inhibitors of this scaffold. Analysis of structure-activity relationship reveals that big hydrophobic substituents on the N-terminus and a methionine amino acid side chain improves inhibitory activity of the thioesters. All these inhibitors are able to restore antibacterial activity of a β-lactam antibiotic against Escherichia coli BL21(DE3) cells producing L1 to that against E. coli cells lacking a β-lactamase. Docking studies reveal that a large N-terminal hydrophobic group results in a slightly different binding mode than smaller hydrophobic groups at the same position. PMID:27595424

  13. Zeb2 recruits HDAC-NuRD to inhibit Notch and controls Schwann cell differentiation and remyelination.

    PubMed

    Wu, Lai Man Natalie; Wang, Jincheng; Conidi, Andrea; Zhao, Chuntao; Wang, Haibo; Ford, Zachary; Zhang, Liguo; Zweier, Christiane; Ayee, Brian G; Maurel, Patrice; Zwijsen, An; Chan, Jonah R; Jankowski, Michael P; Huylebroeck, Danny; Lu, Q Richard

    2016-08-01

    The mechanisms that coordinate and balance a complex network of opposing regulators to control Schwann cell (SC) differentiation remain elusive. Here we demonstrate that zinc-finger E-box-binding homeobox 2 (Zeb2, also called Sip1) transcription factor is a critical intrinsic timer that controls the onset of SC differentiation by recruiting histone deacetylases HDAC 1 and 2 (HDAC1/2) and nucleosome remodeling and deacetylase complex (NuRD) co-repressor complexes in mice. Zeb2 deletion arrests SCs at an undifferentiated state during peripheral nerve development and inhibits remyelination after injury. Zeb2 antagonizes inhibitory effectors including Notch and Sox2. Importantly, genome-wide transcriptome analysis reveals a Zeb2 target gene encoding the Notch effector Hey2 as a potent inhibitor for Schwann cell differentiation. Strikingly, a genetic Zeb2 variant associated with Mowat-Wilson syndrome disrupts the interaction with HDAC1/2-NuRD and abolishes Zeb2 activity for SC differentiation. Therefore, Zeb2 controls SC maturation by recruiting HDAC1/2-NuRD complexes and inhibiting a Notch-Hey2 signaling axis, pointing to the critical role of HDAC1/2-NuRD activity in peripheral neuropathies caused by ZEB2 mutations. PMID:27294509

  14. Inhibitors of amino acids biosynthesis as antifungal agents.

    PubMed

    Jastrzębowska, Kamila; Gabriel, Iwona

    2015-02-01

    Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

  15. Synthesis of tartaric acid analogues of FR258900 and their evaluation as glycogen phosphorylase inhibitors.

    PubMed

    Varga, Gergely; Docsa, Tibor; Gergely, Pál; Juhász, László; Somsák, László

    2013-03-15

    Di-O-cinnamoylated, -p-coumaroylated, and -feruloylated d-, l- and meso-tartaric acids were synthesized as analogues of the natural product FR258900, a glycogen phosphorylase (GP) inhibitor with in vivo antihyperglycaemic activity. The new compounds inhibited rabbit muscle GP in the low micromolar range, and bound to the allosteric site of the enzyme. The best inhibitor was 2,3-di-O-feruloyl meso-tartaric acid and had Ki values of 2.0μM against AMP (competitive) and 3.36μM against glucose-1-phosphate (non-competitive).

  16. Compression regulates gene expression of chondrocytes through HDAC4 nuclear relocation via PP2A-dependent HDAC4 dephosphorylation.

    PubMed

    Chen, Chongwei; Wei, Xiaochun; Wang, Shaowei; Jiao, Qiang; Zhang, Yang; Du, Guoqing; Wang, Xiaohu; Wei, Fangyuan; Zhang, Jianzhong; Wei, Lei

    2016-07-01

    Biomechanics plays a critical role in the modulation of chondrocyte function. The mechanisms by which mechanical loading is transduced into intracellular signals that regulate chondrocyte gene expression remain largely unknown. Histone deacetylase 4 (HDAC4) is specifically expressed in chondrocytes. Mice lacking HDAC4 display chondrocyte hypertrophy, ectopic and premature ossification, and die early during the perinatal period. HDAC4 has a remarkable ability to translocate between the cell's cytoplasm and nucleus. It has been established that subcellular relocation of HDAC4 plays a critical role in chondrocyte differentiation and proliferation. However, it remains unclear whether subcellular relocation of HDAC4 in chondrocytes can be induced by mechanical loading. In this study, we first report that compressive loading induces HDAC4 relocation from the cytoplasm to the nucleus of chondrocytes via stimulation of Ser/Thr-phosphoprotein phosphatases 2A (PP2A) activity, which results in dephosphorylation of HDAC4. Dephosphorylated HDAC4 relocates to the nucleus to achieve transcriptional repression of Runx2 and regulates chondrocyte gene expression in response to compression. Our results elucidate the mechanism by which mechanical compression regulates chondrocyte gene expression through HDAC4 relocation from the cell's cytoplasm to the nucleus via PP2A-dependent HDAC4 dephosphorylation.

  17. Thiol containing compounds and amino acid hydroxamates as reversible synthetic inhibitors of Astacus protease.

    PubMed

    Wolz, R L; Zeggaf, C; Stöcker, W; Zwilling, R

    1990-09-01

    Reversible synthetic inhibitors are characterized for Astacus protease, a 22,614-Da zinc containing neutral endopeptidase from the digestive tract of crayfish. Effective inhibition was demonstrated for several simple thiol containing compounds and a series of amino acid hydroxamates. Both classes of inhibitors had ID50 values ranging from 10(-2) to 10(-4) M for inhibition of hydrolysis of succinyl-Ala-Ala-Ala-p-nitroanilide. Tyrosine hydroxamate was found to be the most effective inhibitor with an ID50 of 175 microM and the mode of inhibition by this compound was determined to be of the simple noncompetitive type. In contrast to the other inhibitors tested, cysteine was seen to partially inactivate the enzyme in a time-dependent manner. The kinetics of this process was studied in detail using progress curve analysis. It was determined that cysteine was acting as a weak chelator and slowly establishing an equilibrium between metallo- and apoenzyme. In the presence of the strong zinc scavenger EDTA, cysteine can, in effect, function as a catalyst in transferring the metal from the protein to the secondary chelator at a rate 10,000 times faster than the rate of unassisted zinc dissociation. The series of amino acid hydroxamates served as probes into the microenvironment of the active site. Possible binding modes of the inhibitors are discussed on the basis of the relationship between the chemical nature of the inhibitor side chains and the strength of inhibition.

  18. Impacts of lignocellulose-derived inhibitors on L-lactic acid fermentation by Rhizopus oryzae.

    PubMed

    Zhang, Li; Li, Xin; Yong, Qiang; Yang, Shang-Tian; Ouyang, Jia; Yu, Shiyuan

    2016-03-01

    Inhibitors generated in the pretreatment and hydrolysis of corn stover and corn cob were identified. In general, they inhibited cell growth, lactate dehydrogenase, and lactic acid production but with less or no adverse effect on alcohol dehydrogenase and ethanol production in batch fermentation by Rhizopus oryzae. Furfural and 5-hydroxymethyl furfural (HMF) were highly toxic at 0.5-1 g L(-1), while formic and acetic acids at less than 4 g L(-1) and levulinic acid at 10 g L(-1) were not toxic. Among the phenolic compounds at 1 g L(-1), trans-cinnamic acid and syringaldehyde had the highest toxicity while syringic, ferulic and p-coumaric acids were not toxic. Although these inhibitors were present at concentrations much lower than their separately identified toxic levels, lactic acid fermentation with the hydrolysates showed much inferior performance compared to the control without inhibitor, suggesting synergistic or compounded effects of the lignocellulose-degraded compounds on inhibiting lactic acid fermentation. PMID:26724548

  19. Hydroxamic acid derivatives of mycophenolic acid inhibit histone deacetylase at the cellular level.

    PubMed

    Batovska, Daniela I; Kim, Dong Hoon; Mitsuhashi, Shinya; Cho, Yoon Sun; Kwon, Ho Jeong; Ubukata, Makoto

    2008-10-01

    Mycophenolic acid (MPA, 1), an inhibitor of IMP-dehydrogenase (IMPDH) and a latent PPARgamma agonist, is used as an effective immunosuppressant for clinical transplantation and recently entered clinical trials in advanced multiple myeloma patients. On the other hand, suberoylanilide hydroxamic acid (SAHA), a non-specific histone deacetylase (HDAC) inhibitor, has been approved for treating cutaneous T-cell lymphoma. MPA seemed to bear a cap, a linker, and a weak metal-binding site as a latent inhibitor of HDAC. Therefore, the hydroxamic acid derivatives of mycophenolic acid having an effective metal-binding site, mycophenolic hydroxamic acid (MPHA, 2), 7-O-acetyl mycophenolic acid (7-O-Ac MPHA, 3), and 7-O-lauroyl mycophenolic hydroxamic acid (7-O-L MPHA, 4) were designed and synthesized. All these compounds inhibited histone deacetylase with IC50 values of 1, 0.9 and 0.5 microM, and cell proliferation at concentrations of 2, 1.5 and 1 microM, respectively. PMID:18838793

  20. Soraphen A, an inhibitor of acetyl CoA carboxylase activity, interferes with fatty acid elongation

    PubMed Central

    Jump, Donald B.; Torres-Gonzalez, Moises; Olson, L. Karl

    2010-01-01

    Acetyl CoA carboxylase (ACC1 & ACC2) generates malonyl CoA, a substrate for de novo lipogenesis (DNL) and an inhibitor of mitochondrial fatty acid β-oxidation (FAO). Malonyl CoA is also a substrate for microsomal fatty acid elongation, an important pathway for saturated (SFA), mono- (MUFA) and polyunsaturated fatty acid (PUFA) synthesis. Despite the interest in ACC as a target for obesity and cancer therapy, little attention has been given to the role ACC plays in long chain fatty acid synthesis. This report examines the effect of pharmacological inhibition of ACC on DNL & palmitate (16:0) and linoleate (18:2,n-6) metabolism in HepG2 and LnCap cells. The ACC inhibitor, soraphen A, lowers cellular malonyl CoA, attenuates DNL and the formation of fatty acid elongation products derived from exogenous fatty acids, i.e., 16:0 & 18:2,n-6; IC50 ~ 5 nM. Elevated expression of fatty acid elongases (Elovl5, Elovl6) or desaturases (FADS1, FADS2) failed to override the soraphen A effect on SFA, MUFA or PUFA synthesis. Inhibition of fatty acid elongation leads to the accumulation of 16- and 18-carbon unsaturated fatty acids derived from 16:0 and 18:2,n-6, respectively. Pharmacological inhibition of ACC activity will not only attenuate DNL and induce FAO, but will also attenuate the synthesis of very long chain saturated, mono- and polyunsaturated fatty acids. PMID:21184748

  1. Binding of α,α-disubstituted amino acids to arginase suggests new avenues for inhibitor design.

    PubMed

    Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P; Thorn, Katherine J; Christianson, David W

    2011-08-11

    Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of α,α-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2-methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase I and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional α-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase.

  2. Binding of [alpha, alpha]-Disubstituted Amino Acids to Arginase Suggests New Avenues for Inhibitor Design

    SciTech Connect

    Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P.; Thorn, Katherine J.; Christianson, David W.

    2011-10-21

    Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of {alpha},{alpha}-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2-methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase I and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional {alpha}-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase.

  3. Curcumin Derivatives as Green Corrosion Inhibitors for α-Brass in Nitric Acid Solution

    NASA Astrophysics Data System (ADS)

    Fouda, A. S.; Elattar, K. M.

    2012-11-01

    1,7- Bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-diene-4-arylazo-3,5-dione I-V have been investigated as corrosion inhibitors for α-brass in 2 M nitric acid solution using weight-loss and galvanostatic polarization techniques. The efficiency of the inhibitors increases with the increase in the inhibitor concentration but decreases with a rise in temperature. The conjoint effect of the curcumin derivatives and KSCN has also been studied. The apparent activation energy ( E a*) and other thermodynamic parameters for the corrosion process have also been calculated. The galvanostatic polarization data indicated that the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The slopes of the cathodic and anodic Tafel lines ( b c and b a) are maintained approximately equal for various inhibitor concentrations. However, the value of the Tafel slopes increases together as inhibitor concentration increases. The adsorption of these compounds on α-brass surface has been found to obey the Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

  4. An Isochemogenic Set of Inhibitors To Define the Therapeutic Potential of Histone Deacetylases in β-Cell Protection.

    PubMed

    Wagner, Florence F; Lundh, Morten; Kaya, Taner; McCarren, Patrick; Zhang, Yan-Ling; Chattopadhyay, Shrikanta; Gale, Jennifer P; Galbo, Thomas; Fisher, Stewart L; Meier, Bennett C; Vetere, Amedeo; Richardson, Sarah; Morgan, Noel G; Christensen, Dan Ploug; Gilbert, Tamara J; Hooker, Jacob M; Leroy, Mélanie; Walpita, Deepika; Mandrup-Poulsen, Thomas; Wagner, Bridget K; Holson, Edward B

    2016-02-19

    Modulation of histone deacetylase (HDAC) activity has been implicated as a potential therapeutic strategy for multiple diseases. However, it has been difficult to dissect the role of individual HDACs due to a lack of selective small-molecule inhibitors. Here, we report the synthesis of a series of highly potent and isoform-selective class I HDAC inhibitors, rationally designed by exploiting minimal structural changes to the clinically experienced HDAC inhibitor CI-994. We used this toolkit of isochemogenic or chemically matched inhibitors to probe the role of class I HDACs in β-cell pathobiology and demonstrate for the first time that selective inhibition of an individual HDAC isoform retains beneficial biological activity and mitigates mechanism-based toxicities. The highly selective HDAC3 inhibitor BRD3308 suppressed pancreatic β-cell apoptosis induced by inflammatory cytokines, as expected, or now glucolipotoxic stress, and increased functional insulin release. In addition, BRD3308 had no effect on human megakaryocyte differentiation, while inhibitors of HDAC1 and 2 were toxic. Our findings demonstrate that the selective inhibition of HDAC3 represents a potential path forward as a therapy to protect pancreatic β-cells from inflammatory cytokines and nutrient overload in diabetes. PMID:26640968

  5. Targeting histone deacetylase inhibitors for anti-malarial therapy.

    PubMed

    Andrews, Katherine T; Tran, Thanh N; Wheatley, Nicole C; Fairlie, David P

    2009-01-01

    It is now clear that histone acetylation plays key roles in regulating gene transcription in both eukaryotes and prokaryotes, the acetylated form inducing gene expression while deacetylation silences genes. Recent studies have identified roles for histone acetyltransferases (HATs) and/or histone deacetylases (HDACs) in a number of parasites including Entamoeba histolytica, Toxoplasma gondii, Schistosoma mansoni, Cryptosporidium sp., Leishmania donovani, Neospora caninum, and Plasmodium falciparum. Here we survey fairly limited efforts to date in profiling antimalarial activities of HDAC inhibitors, showing that such compounds are potent inhibitors of the growth of P. falciparum in vitro and in vivo. Most of the compounds evaluated so far have borne a zinc-binding hydroxamate group that tends to be metabolized in vivo, and thus new zinc-binding groups need to be incorporated into second generation inhibitors in order to mask the catalytic zinc in the active site of HDACs. Also the development of compounds that are selective for parasitic HDACs over mammalian HDACs is still in relative infancy and it will take some time to derive antiparasitic HDAC inhibitor compounds with minimal toxicity for the host and acceptable pharmacokinetic and pharmacodynamic profiles for human treatment. Nevertheless, results to date suggest that HDAC inhibitor development represents a promising new approach to the potential treatment of parasitic infections, including those induced by malaria protozoa, and may offer new therapeutic targets within increasingly drug-resistant malarial parasites. PMID:19355992

  6. Aurora-B and HDAC synergistically regulate survival and proliferation of lymphoma cell via AKT, mTOR and Notch pathways.

    PubMed

    Wang, Chong; Chen, Jing; Cao, Weijie; Sun, Ling; Sun, Hui; Liu, Yanfang

    2016-05-15

    Aurora-B is a protein kinase that functions mainly in the attachment of the mitotic spindle to the centromere. Overexpression of Aurora-B causes unequal distribution of genetic information, creating aneuploidy cells, a hallmark of cancer. Histone deacetylases (HDACs) are a class of enzymes that remove acetyl groups from a ε-N-acetyl lysine amino acid on a histone, allowing the histones to wrap the DNA more tightly, thus globally regulating gene transcription. Additionally, these HDACs can also modify non-histone proteins. Inhibition of HDACs is a potent strategy for cancer treatment. Here, we report that inhibition of Aurora-B and HDAC exerts similar tumor suppressive effects in cells. Knockdown of Aurora-B or inhibition of HDAC achieved the same effect on repression of cell proliferation. Furthermore, we found that the tumor suppressive effect of Aurora-B and HDAC inhibition is due to the induction of cell cycle arrest and/or apoptosis. Mechanistically, we demonstrated that Aurora-B and HDAC can cooperatively regulate AKT, mTOR and Notch pathways.

  7. Trypsin inhibitors from ridged gourd (Luffa acutangula Linn.) seeds: purification, properties, and amino acid sequences.

    PubMed

    Haldar, U C; Saha, S K; Beavis, R C; Sinha, N K

    1996-02-01

    Two trypsin inhibitors, LA-1 and LA-2, have been isolated from ridged gourd (Luffa acutangula Linn.) seeds and purified to homogeneity by gel filtration followed by ion-exchange chromatography. The isoelectric point is at pH 4.55 for LA-1 and at pH 5.85 for LA-2. The Stokes radius of each inhibitor is 11.4 A. The fluorescence emission spectrum of each inhibitor is similar to that of the free tyrosine. The biomolecular rate constant of acrylamide quenching is 1.0 x 10(9) M-1 sec-1 for LA-1 and 0.8 x 10(9) M-1 sec-1 for LA-2 and that of K2HPO4 quenching is 1.6 x 10(11) M-1 sec-1 for LA-1 and 1.2 x 10(11) M-1 sec-1 for LA-2. Analysis of the circular dichroic spectra yields 40% alpha-helix and 60% beta-turn for La-1 and 45% alpha-helix and 55% beta-turn for LA-2. Inhibitors LA-1 and LA-2 consist of 28 and 29 amino acid residues, respectively. They lack threonine, alanine, valine, and tryptophan. Both inhibitors strongly inhibit trypsin by forming enzyme-inhibitor complexes at a molar ratio of unity. A chemical modification study suggests the involvement of arginine of LA-1 and lysine of LA-2 in their reactive sites. The inhibitors are very similar in their amino acid sequences, and show sequence homology with other squash family inhibitors. PMID:8924202

  8. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    SciTech Connect

    Becker, Jan C. . E-mail: beckeja@uni-muenster.de; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  9. Organic corrosion inhibitors for aluminum in perchloric acid

    SciTech Connect

    Metikos-Hukovic, M.; Stupnisek-Lisac, E. . Dept. of Electrochemistry); Grubac, Z. . Dept. of Inorganic Chemistry)

    1994-02-01

    Substituted N-arylpyrroles containing carbaldehyde groups on a pyrrole ring and their inhibitive effects on the corrosion of aluminum (Al) in perchloric acid (HCIO[sub 4]) were investigated. Electrochemical measurements showed the organic compounds examined had good inhibiting properties at 40 C. The high inhibition effect of the N-aryl-2,5-dimethylpyrroles containing carbaldehyde groups on a pyrrole ring on corrosion of Al in acid media was explained on the basis of the electronic structure of the molecule and by the condensation characteristic of the carbaldehydes. Investigation of the influence of substitution type ([minus]F,[minus]Cl,[minus]NH[sub 2]) on the inhibiting characteristics of examined organic compounds showed the best inhibiting effect was from substituted N-arylpyrrole with fluorine in the ortho position of the phenyl ring.

  10. HALOACETIC ACIDS AND KINASE INHIBITORS PERTURB MOUSE NEURAL CREST CELLS IN VITRO

    EPA Science Inventory

    HUNTER, E.S.1, J. SMITH2, J. ANDREWS1. 1 Reproductive Toxicology Division, NHEERL, US EPA, Research Triangle Park and 2 Department of Cell and Developmental Biology, UNC-CH, Chapel Hill, North Carolina. Haloacetic acids and kinase inhibitors perturb mouse neural crest cells in vi...

  11. Synergism of antifungal activity between mitochondrial respiration inhibitors and kojic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Co-application of certain types of compounds with conventional antimicrobial drugs results in the enhancement of efficacy of drugs through a mechanism termed chemosensitization. We show that kojic acid (KA), a natural product, is a potent chemosensitizer to complex III inhibitors of mitochondrial re...

  12. Histone Deacetylase Inhibitors Preserve Function in Aging Axons

    PubMed Central

    Baltan, Selva

    2012-01-01

    Aging increases the vulnerability of aging white matter to ischemic injury. Histone deacetylase (HDAC) inhibitors preserve young adult white matter structure and function during ischemia by conserving ATP and reducing excitotoxicity. In isolated optic nerve from 12 month old mice, deprived of oxygen and glucose, we show that pan- and Class I specific HDAC inhibitors promote functional recovery of axons. This protection correlates with preservation of axonal mitochondria. The cellular expression of HDAC 3, in the central nervous system (CNS) and HDAC 2 in optic nerve considerably changed with age expanding to more cytoplasmic domains from nuclear compartments suggesting that changes in glial cell protein acetylation may confer protection to aging axons. Our results indicate manipulation of HDAC activities in glial cells may have a universal potential for stroke therapy across age groups. PMID:23050648

  13. Fatty acid amide hydrolase inhibitors confer anti-invasive and antimetastatic effects on lung cancer cells

    PubMed Central

    Winkler, Katrin; Ramer, Robert; Dithmer, Sophie; Ivanov, Igor; Merkord, Jutta; Hinz, Burkhard

    2016-01-01

    Inhibition of endocannabinoid degradation has been suggested as tool for activation of endogenous tumor defense. One of these strategies lies in blockade of fatty acid amide hydrolase (FAAH) which catalyzes the degradation of endocannabinoids (anandamide [AEA], 2-arachidonoylglycerol [2-AG]) and endocannabinoid-like substances (N-oleoylethanolamine [OEA], N-palmitoylethanolamine [PEA]). This study addressed the impact of two FAAH inhibitors (arachidonoyl serotonin [AA-5HT], URB597) on A549 lung cancer cell metastasis and invasion. LC-MS analyses revealed increased levels of FAAH substrates (AEA, 2-AG, OEA, PEA) in cells incubated with either FAAH inhibitor. In athymic nude mice FAAH inhibitors were shown to elicit a dose-dependent antimetastatic action yielding a 67% and 62% inhibition of metastatic lung nodules following repeated administration of 15 mg/kg AA-5HT and 5 mg/kg URB597, respectively. In vitro, a concentration-dependent anti-invasive action of either FAAH inhibitor was demonstrated, accompanied with upregulation of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Using siRNA approaches, a causal link between the TIMP-1-upregulating and anti-invasive action of FAAH inhibitors was confirmed. Moreover, knockdown of FAAH by siRNA was shown to confer decreased cancer cell invasiveness and increased TIMP-1 expression. Inhibitor experiments point toward a role of CB2 and transient receptor potential vanilloid 1 in conferring anti-invasive effects of FAAH inhibitors and FAAH siRNA. Finally, antimetastatic and anti-invasive effects were confirmed for all FAAH substrates with AEA and OEA causing a TIMP-1-dependent anti-invasive action. Collectively, the present study provides first-time proof for an antimetastatic action of FAAH inhibitors. As mechanism of its anti-invasive properties an upregulation of TIMP-1 was identified. PMID:26930716

  14. Structure-based design of non-natural amino-acid inhibitors of amyloid fibril formation

    SciTech Connect

    Sievers, Stuart A.; Karanicolas, John; Chang, Howard W.; Zhao, Anni; Jiang, Lin; Zirafi, Onofrio; Stevens, Jason T.; Münch, Jan; Baker, David; Eisenberg, David

    2011-09-20

    Many globular and natively disordered proteins can convert into amyloid fibrils. These fibrils are associated with numerous pathologies as well as with normal cellular functions, and frequently form during protein denaturation. Inhibitors of pathological amyloid fibril formation could be useful in the development of therapeutics, provided that the inhibitors were specific enough to avoid interfering with normal processes. Here we show that computer-aided, structure-based design can yield highly specific peptide inhibitors of amyloid formation. Using known atomic structures of segments of amyloid fibrils as templates, we have designed and characterized an all-D-amino-acid inhibitor of the fibril formation of the tau protein associated with Alzheimer's disease, and a non-natural L-amino-acid inhibitor of an amyloid fibril that enhances sexual transmission of human immunodeficiency virus. Our results indicate that peptides from structure-based designs can disrupt the fibril formation of full-length proteins, including those, such as tau protein, that lack fully ordered native structures. Because the inhibiting peptides have been designed on structures of dual-{beta}-sheet 'steric zippers', the successful inhibition of amyloid fibril formation strengthens the hypothesis that amyloid spines contain steric zippers.

  15. Discovery and molecular basis of potent noncovalent inhibitors of fatty acid amide hydrolase (FAAH)

    PubMed Central

    Min, Xiaoshan; Thibault, Stephen T.; Porter, Amy C.; Gustin, Darin J.; Carlson, Timothy J.; Xu, Haoda; Lindstrom, Michelle; Xu, Guifen; Uyeda, Craig; Ma, Zhihua; Li, Yihong; Kayser, Frank; Walker, Nigel P. C.; Wang, Zhulun

    2011-01-01

    Fatty acid amide hydrolase (FAAH), an amidase-signature family member, is an integral membrane enzyme that degrades lipid amides including the endogenous cannabinoid anandamide and the sleep-inducing molecule oleamide. Both genetic knock out and pharmacological administration of FAAH inhibitors in rodent models result in analgesic, anxiolytic, and antiinflammatory phenotypes. Targeting FAAH activity, therefore, presents a promising new therapeutic strategy for the treatment of pain and other neurological-related or inflammatory disorders. Nearly all FAAH inhibitors known to date attain their binding potency through a reversible or irreversible covalent modification of the nucleophile Ser241 in the unusual Ser-Ser-Lys catalytic triad. Here, we report the discovery and mechanism of action of a series of ketobenzimidazoles as unique and potent noncovalent FAAH inhibitors. Compound 2, a representative of these ketobenzimidazoles, was designed from a series of ureas that were identified from high-throughput screening. While urea compound 1 is characterized as an irreversible covalent inhibitor, the cocrystal structure of FAAH complexed with compound 2 reveals that these ketobenzimidazoles, though containing a carbonyl moiety, do not covalently modify Ser241. These inhibitors achieve potent inhibition of FAAH activity primarily from shape complementarity to the active site and through numerous hydrophobic interactions. These noncovalent compounds exhibit excellent selectivity and good pharmacokinetic properties. The discovery of this distinctive class of inhibitors opens a new avenue for modulating FAAH activity through nonmechanism-based inhibition. PMID:21502526

  16. A proapoptotic effect of valproic acid on progenitors of embryonic stem cell-derived glutamatergic neurons

    PubMed Central

    Fujiki, R; Sato, A; Fujitani, M; Yamashita, T

    2013-01-01

    Valproic acid (VPA) is a branched-chain saturated fatty acid with a long history of clinical use as an antiepileptic drug (AED). VPA is also known to inhibit histone deacetylases (HDACs) and to cause diverse effects on neural progenitor cells (NPCs) and neurons. Although the neuroprotective or neurodestructive effects of VPA have been investigated in heterogeneous cell populations, in this study, we used homogeneous populations of NPCs and glutamatergic cortical pyramidal neurons, which were differentiated from embryonic stem (ES) cells. At therapeutic concentrations, VPA had a proapoptotic effect on ES cell-derived NPCs of glutamatergic neurons, but not on their progeny. This effect of VPA most likely occurred through the inhibition of HDACs, because similar phenotypes were observed following treatment with other HDAC inhibitors (HDACis) such as trichostatin A and sodium butyrate. The proapoptotic phenotype was not observed when cells were exposed to a structural analog of VPA, valpromide (VPM), which has the same antiepileptic effect as VPA, but does not inhibit HDACs. Western blotting confirmed that treatment with HDACis, but not VPM, significantly increased the levels of histone H3 acetylation in NPCs. HDACi treatments did not affect the survival of neurons, although the acetylation levels were increased to a limited extent. These results, which are based on a homogeneous culture system, suggest that VPA inhibits HDAC activity and induces the apoptosis of NPCs that are fated to differentiate into glutamatergic neurons. The dose-dependent effects of VPA both on apoptosis and hyperacetylation of histone H3 in NPCs supported this notion. These cell type- and differentiation stage-specific effects of VPA imply that dysfunction of HDACs during pregnancy significantly increase the risk of congenital malformations associated with VPA administration. PMID:23788034

  17. Identification of Anziaic Acid, a Lichen Depside from Hypotrachyna sp., as a New Topoisomerase Poison Inhibitor

    PubMed Central

    Cheng, Bokun; Cao, Shugeng; Vasquez, Victor; Annamalai, Thirunavukkarasu; Tamayo-Castillo, Giselle; Clardy, Jon; Tse-Dinh, Yuk-Ching

    2013-01-01

    Topoisomerase inhibitors are effective for antibacterial and anticancer therapy because they can lead to the accumulation of the intermediate DNA cleavage complex formed by the topoisomerase enzymes, which trigger cell death. Here we report the application of a novel enzyme-based high-throughput screening assay to identify natural product extracts that can lead to increased accumulation of the DNA cleavage complex formed by recombinant Yersinia pestis topoisomerase I as part of a larger effort to identify new antibacterial compounds. Further characterization and fractionation of the screening positives from the primary assay led to the discovery of a depside, anziaic acid, from the lichen Hypotrachyna sp. as an inhibitor for both Y. pestis and Escherichia coli topoisomerase I. In in vitro assays, anziaic acid exhibits antibacterial activity against Bacillus subtilis and a membrane permeable strain of E. coli. Anziaic acid was also found to act as an inhibitor of human topoisomerase II but had little effect on human topoisomerase I. This is the first report of a depside with activity as a topoisomerase poison inhibitor and demonstrates the potential of this class of natural products as a source for new antibacterial and anticancer compounds. PMID:23593306

  18. Triacontanol negatively modulates the jasmonic acid-stimulated proteinase inhibitors in tomato (Lycopersicon esculentum).

    PubMed

    Ramanarayan, Krishnamurthy; Swamy, Gangadharamurthy Sivakumar

    2004-04-01

    Triacontanol (TRIA), a long chain aliphatic alcohol (C30H61OH) reverses the effect of jasmonic acid (JA) in inducing proteinase inhibitors (PIs) in tomato leaves. Porcine pancreas trypsin and Spodoptera litura gut proteinases were inhibited in the presence of leaf proteins treated with JA, and TRIA partially reverses this effect. Spodoptera litura larvae fed with tomato leaves treated with JA were reduced in body weight and TRIA is able to partially reverse this JA-induced effect. These results reflect the partial reversal effect of TRIA in down regulating the JA-induced production of proteinase inhibitors.

  19. Histone Deacetylase Inhibitors Modulates the Induction and Expression of Amphetamine-induced Behavioral Sensitization Partially Through an Associated Learning of the Environment in Mice

    PubMed Central

    Kalda, Anti; Heidmets, Lenne-Triin; Shen, Hai-ying; Zharkovsky, Alexander; Chen, Jiang-Fan

    2010-01-01

    The behavioral sensitization produced by repeated amphetamine treatment may represent the neural adaptations underlying some of the features of psychosis and addiction in humans. Chromatin modification (specifically histone hyperacetylation) was recently recognized as an important regulator of psychostimulant-induced plasticity. We have investigated the effects of treatment with the histone deacetylase (HDAC) inhibitors butyric acid (BA, 630 mg/kg, i.p) and valproic acid (VPA, 175 mg/kg, i.p.) on the psyhcostimulant locomotor sensitization induced by amphetamine (AMPH, 2.0 mg/kg, i.p.). Neither BA nor VPA had locomotor effects alone, but both significantly potentiated the amphetamine-induced behavioral sensitization in mice. At the molecular level, VPA and amphetamine produced an increase of histone H4 acetylation in the striatum as detected by Western blot analysis, while co-treatment with VPA and AMPH produced an additive effect on histone H4 acetylation. We then administered the HDAC inhibitors after treatment with amphetamine for 8 days to establish locomotor sensitization. We found that repeated administration of VPA or BA for 6 days inhibited the expression of sensitized response following amphetamine challenge. Finally, in a context-specific model we studied the effect of HDAC inhibitors on amphetamine-induced association of the treatment environment (associative learning). We found that VPA and BA enhance the context-specificity of expression of amphetamine sensitization. Thus, HDAC inhibitors differentially modulate the induction and expression of amphetamine-induced effects. Together, these results suggest that dynamic changes in chromatin modification may be an important mechanism underlying amphetamine-induced neuronal plasticity and associative learning. PMID:17477979

  20. Computer-aided identification of new histone deacetylase 6 selective inhibitor with anti-sepsis activity.

    PubMed

    Yoo, Jakyung; Kim, So-Jin; Son, Dohyun; Seo, Heewon; Baek, Seung Yeop; Maeng, Cheol-Young; Lee, Changsik; Kim, In Su; Jung, Young Hoon; Lee, Sun-Mee; Park, Hyun-Ju

    2016-06-30

    Histone deacetylase (HDAC) inhibitors have been recognized as promising approaches to the treatment of various human diseases including cancer, inflammation, neurodegenerative diseases, and metabolic disorders. Several pan-HDAC inhibitors are currently approved only as anticancer drugs. Interestingly, SAHA (vorinostat), one of clinically available pan-HDAC inhibitors, shows an anti-inflammatory effect at concentrations lower than those required for inhibition of tumor cell growth. It was also reported that HDAC6 selective inhibitor tubastatin A has anti-inflammatory and anti-rheumatic effect. In our efforts to develop novel HDAC inhibitors, we rationally designed various HDAC inhibitors based on the structures of two hit compounds identified by virtual screening of chemical database. Among them, 9a ((E)-N-hydroxy-4-(2-styrylthiazol-4-yl)butanamide) was identified as a HDAC6 selective inhibitor (IC50 values of 0.199 μM for HDAC6 versus 13.8 μM for HDAC1), and it did not show significant cytotoxicity against HeLa cells. In vivo biological evaluation of 9a was conducted on a lipopolysaccharide (LPS)-induced mouse model of sepsis. The compound 9a significantly improved 40% survival rate (P = 0.0483), and suppressed the LPS-induced increase of TNF-α and IL-6 mRNA expression in the liver of mice. Our study identified novel HDAC6 selective inhibitor 9a, which may serve as a potential lead for the development of anti-inflammatory or anti-sepsis agents. PMID:27060764

  1. A dual inhibitor of cyclooxygenase and 5-lipoxygenase protects against kainic acid-induced brain injury.

    PubMed

    Minutoli, Letteria; Marini, Herbert; Rinaldi, Mariagrazia; Bitto, Alessandra; Irrera, Natasha; Pizzino, Gabriele; Pallio, Giovanni; Calò, Margherita; Adamo, Elena Bianca; Trichilo, Vincenzo; Interdonato, Monica; Galfo, Federica; Squadrito, Francesco; Altavilla, Domenica

    2015-06-01

    Systemic administration of kainic acid causes inflammation and apoptosis in the brain, resulting in neuronal loss. Dual cyclooxygenase/5-lipoxygenase (COX/5-LOX) inhibitors could represent a possible neuroprotective approach in preventing glutamate excitotoxicity. Consequently, we investigated the effects of a dual inhibitor of COX/5-LOX following intraperitoneal administration of kainic acid (KA, 10 mg/kg) in rats. Animals were randomized to receive either the dual inhibitor of COX/5-LOX (flavocoxid, 20 mg/kg i.p.) or its vehicle (1 ml/kg i.p.) 30 min after KA administration. Sham brain injury rats were used as controls. We evaluated protein expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2) and tumor necrosis factor alpha (TNF-α) as well as levels of malondialdehyde (MDA), prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in the hippocampus. Animals were also observed for monitoring behavioral changes according to Racine Scale. Finally, histological analysis and brain edema evaluation were carried out. Treatment with the dual inhibitor of COX/5-LOX decreased protein expression of p-ERK1/2 and TNF-α in hippocampus, markedly reduced MDA, LTB4 and PGE2 hippocampal levels, and also ameliorated brain edema. Histological analysis showed a reduction in cell damage in rats treated with the dual inhibitor of COX/5-LOX, particularly in hippocampal subregion CA3c. Moreover, flavocoxid significantly improved behavioral signs following kainic acid administration. Our results suggest that dual inhibition of COX/5-LOX by flavocoxid has neuroprotective effects during kainic acid-induced excitotoxicity. PMID:25893744

  2. Histone deacetylase-1 (HDAC1) is a molecular switch between neuronal survival and death.

    PubMed

    Bardai, Farah H; Price, Valerie; Zaayman, Marcus; Wang, Lulu; D'Mello, Santosh R

    2012-10-12

    Both neuroprotective and neurotoxic roles have previously been described for histone deacetylase-1 (HDAC1). Here we report that HDAC1 expression is elevated in vulnerable brain regions of two mouse models of neurodegeneration, the R6/2 model of Huntington disease and the Ca(2+)/calmodulin-dependent protein kinase (CaMK)/p25 double-transgenic model of tauopathic degeneration, suggesting a role in promoting neuronal death. Indeed, elevating HDAC1 expression by ectopic expression promotes the death of otherwise healthy cerebellar granule neurons and cortical neurons in culture. The neurotoxic effect of HDAC1 requires interaction and cooperation with HDAC3, which has previously been shown to selectively induce the death of neurons. HDAC1-HDAC3 interaction is greatly elevated under conditions of neurodegeneration both in vitro and in vivo. Furthermore, the knockdown of HDAC3 suppresses HDAC1-induced neurotoxicity, and the knockdown of HDAC1 suppresses HDAC3 neurotoxicity. As described previously for HDAC3, the neurotoxic effect of HDAC1 is inhibited by treatment with IGF-1, the expression of Akt, or the inhibition of glycogen synthase kinase 3β (GSK3β). In addition to HDAC3, HDAC1 has been shown to interact with histone deacetylase-related protein (HDRP), a truncated form of HDAC9, whose expression is down-regulated during neuronal death. In contrast to HDAC3, the interaction between HDRP and HDAC1 protects neurons from death, an effect involving acquisition of the deacetylase activity of HDAC1 by HDRP. We find that elevated HDRP inhibits HDAC1-HDAC3 interaction and prevents the neurotoxic effect of either of these two proteins. Together, our results suggest that HDAC1 is a molecular switch between neuronal survival and death. Its interaction with HDRP promotes neuronal survival, whereas interaction with HDAC3 results in neuronal death. PMID:22918830

  3. Discovery of highly potent acid ceramidase inhibitors with in vitro tumor chemosensitizing activity

    PubMed Central

    Realini, Natalia; Solorzano, Carlos; Pagliuca, Chiara; Pizzirani, Daniela; Armirotti, Andrea; Luciani, Rosaria; Costi, Maria Paola; Bandiera, Tiziano; Piomelli, Daniele

    2013-01-01

    The expression of acid ceramidase (AC) – a cysteine amidase that hydrolyses the proapoptotic lipid ceramide – is abnormally high in several human tumors, which is suggestive of a role in chemoresistance. Available AC inhibitors lack, however, the potency and drug-likeness necessary to test this idea. Here we show that the antineoplastic drug carmofur, which is used in the clinic to treat colorectal cancers, is a potent AC inhibitor and that this property is essential to its anti-proliferative effects. Modifications in the chemical scaffold of carmofur yield new AC inhibitors that act synergistically with standard antitumoral drugs to prevent cancer cell proliferation. These findings identify AC as an unexpected target for carmofur, and suggest that this molecule can be used as starting point for the design of novel chemosensitizing agents. PMID:23301156

  4. Amino acid sequence of a protease inhibitor isolated from Sarcophaga bullata determined by mass spectrometry.

    PubMed

    Papayannopoulos, I A; Biemann, K

    1992-02-01

    The amino acid sequence of a protease inhibitor isolated from the hemolymph of Sarcophaga bullata larvae was determined by tandem mass spectrometry. Homology considerations with respect to other protease inhibitors with known primary structures assisted in the choice of the procedure followed in the sequence determination and in the alignment of the various peptides obtained from specific chemical cleavage at cysteines and enzyme digests of the S. bullata protease inhibitor. The resulting sequence of 57 residues is as follows: Val Asp Lys Ser Ala Cys Leu Gln Pro Lys Glu Val Gly Pro Cys Arg Lys Ser Asp Phe Val Phe Phe Tyr Asn Ala Asp Thr Lys Ala Cys Glu Glu Phe Leu Tyr Gly Gly Cys Arg Gly Asn Asp Asn Arg Phe Asn Thr Lys Glu Glu Cys Glu Lys Leu Cys Leu.

  5. Largazole, a class I histone deacetylase inhibitor, enhances TNF-α-induced ICAM-1 and VCAM-1 expression in rheumatoid arthritis synovial fibroblasts.

    PubMed

    Ahmed, Salahuddin; Riegsecker, Sharayah; Beamer, Maria; Rahman, Ayesha; Bellini, Joseph V; Bhansali, Pravin; Tillekeratne, L M Viranga

    2013-07-15

    In the present study, we evaluated the effect of largazole (LAR), a marine-derived class I HDAC inhibitor, on tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and matrix metalloproteinase-2 (MMP-2) activity. LAR (1-5 μM) had no adverse effect on the viability of RA synovial fibroblasts. Among the different class I HDACs screened, LAR (0.5-5 μM) inhibited the constitutive expression of HDAC1 (0-30%). Surprisingly, LAR increased class II HDAC [HDAC6] by ~220% with a concomitant decrease in HDAC5 [30-58%] expression in RA synovial fibroblasts. SAHA (5 μM), a pan-HDAC inhibitor, also induced HDAC6 expression in RA synovial fibroblasts. Pretreatment of RA synovial fibroblasts with LAR further enhanced TNF-α-induced ICAM-1 and VCAM-1 expression. However, LAR inhibited TNF-α-induced MMP-2 activity in RA synovial fibroblasts by 35% when compared to the TNF-α-treated group. Further, the addition of HDAC6 specific inhibitor Tubastatin A with LAR suppressed TNF-α+LAR-induced ICAM-1 and VCAM-1 expression and completely blocked MMP-2 activity, suggesting a role of HDAC6 in LAR-induced ICAM-1 and VCAM-1 expression. LAR also enhanced TNF-α-induced phospho-p38 and phospho-AKT expression, but inhibited the expression of phospho-JNK and nuclear translocation of NF-κBp65 in RA synovial fibroblasts. These results suggest that LAR activates p38 and Akt pathways and influences class II HDACs, in particular HDAC6, to enhance some of the detrimental effects of TNF-α in RA synovial fibroblasts. Understanding the exact role of different HDAC isoenzymes in RA pathogenesis is extremely important in order to develop highly effective HDAC inhibitors for the treatment of RA.

  6. N-Benzyl-indolo carboxylic acids: Design and synthesis of potent and selective adipocyte fatty-acid binding protein (A-FABP) inhibitors.

    PubMed

    Barf, Tjeerd; Lehmann, Fredrik; Hammer, Kristin; Haile, Saba; Axen, Eva; Medina, Carmen; Uppenberg, Jonas; Svensson, Stefan; Rondahl, Lena; Lundbäck, Thomas

    2009-03-15

    Small molecule inhibitors of adipocyte fatty-acid binding protein (A-FABP) have gained renewed interest following the recent publication of pharmacologically beneficial effects of such inhibitors. Despite the potential utility of selective A-FABP inhibitors within the fields of metabolic disease, inflammation and atherosclerosis, there are few examples of useful A-FABP inhibitors in the public domain. Herein, we describe the optimization of N-benzyl-tetrahydrocarbazole derivatives through the use of co-crystal structure guided medicinal chemistry efforts. This led to the identification of a potent and selective class of A-FABP inhibitors as illustrated by N-benzyl-hexahydrocyclohepta[b]indole 30. PMID:19217286

  7. Lichen secondary metabolite evernic acid as potential quorum sensing inhibitor against Pseudomonas aeruginosa.

    PubMed

    Gökalsın, Barış; Sesal, Nüzhet Cenk

    2016-09-01

    Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential. Lichens have ethnobotanical value for their medicinal properties and it is possible that their secondary metabolites have quorum sensing inhibitor properties. This study aims to investigate an alternative treatment approach by utilizing lichen secondary metabolite evernic acid to reduce the expressions of Pseudomonas aeruginosa virulence factors by inhibiting quorum sensing. For this purpose, fluorescent monitor strains were utilized for quorum sensing inhibitor screens and quantitative reverse-transcriptase PCR analyses were conducted for comparison. Results indicate that evernic acid is capable of inhibiting Pseudomonas aeruginosa quorum sensing systems. PMID:27465850

  8. 3-Arylpropionylhydroxamic acid derivatives as Helicobacter pylori urease inhibitors: Synthesis, molecular docking and biological evaluation.

    PubMed

    Shi, Wei-Kang; Deng, Rui-Cheng; Wang, Peng-Fei; Yue, Qin-Qin; Liu, Qi; Ding, Kun-Ling; Yang, Mei-Hui; Zhang, Hong-Yu; Gong, Si-Hua; Deng, Min; Liu, Wen-Run; Feng, Qiu-Ju; Xiao, Zhu-Ping; Zhu, Hai-Liang

    2016-10-01

    Helicobacter pylori urease is involved in several physiologic responses such as stomach and duodenal ulcers, adenocarcinomas and stomach lymphomas. Thus, inhibition of urease is taken for a good chance to treat H. pylori-caused infections, we have therefore focused our efforts on seeking novel urease inhibitors. Here, a series of arylpropionylhydroxamic acids were synthesized and evaluated for urease inhibition. Out of these compounds, 3-(2-benzyloxy-5-chlorophenyl)-3-hydroxypropionylhydroxamic acid (d24) was the most active inhibitor with IC50 of 0.15±0.05μM, showing a mixed inhibition with both competitive and uncompetitive aspects. Non-linear fitting of kinetic data gives kinetics parameters of 0.13 and 0.12μg·mL(-1) for Ki and Ki', respectively. The plasma protein binding assays suggested that d24 exhibited moderate binding to human and rabbit plasma proteins. PMID:27492194

  9. Natural indoles, indole-3-carbinol and 3,3′-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression

    SciTech Connect

    Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S.

    2014-01-01

    Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3′-diindolylmethane (DIM), found in cruciferous vegetables, to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8{sup +} T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors. - Highlights: • I3C and DIM reduce SEB-induced T cell activation and inflammatory cytokines. • Inhibiting class I HDACs reduces T cell activation and inflammatory cytokines. • Inhibiting class II HDACs increases T cell activation and inflammatory cytokines. • I3C and DIM selectively reduce mRNA expression of class I HDACs. • Novel use and mechanism to counteract

  10. Synthesis and evaluation of aminophosphinic acid derivatives as inhibitors of renal dipeptidase.

    PubMed

    Gurulingappa, Hallur; Buckhalts, Phillip; Kinzler, Kenneth W; Vogelstein, Bert; Khan, Saeed R

    2004-07-01

    Renal dipeptidase (RDP) is an enzyme overexpressed in benign and malignant colorectal tumors. In an effort to identify potent inhibitors of this enzyme, a series of aminophosphinic acid derivatives were synthesized. Compounds 3a and 3c in which the phenyl ring was para substituted with F and Br and olefin with Z geometry, showed better inhibitory activity against RDP enzyme (IC50 = 5-6 nM).

  11. Products of the Black Sea alga Phyllophora nervosa as corrosion inhibitor for steel in acids

    SciTech Connect

    Popelyukh, G.M.; Andrianov, A.M.; Burtnenko, L.M.; Gazha, P.A.; Talavira, L.I.

    1986-05-01

    The authors have investigated the inhibiting properties of the processing products of the Black Sea red seaweed Phyllophora nervosa on specimens of steel St3 in phosphoric and hydrochloric acids of various concentrations at temperatures in the range from 30 to 95 /sup 0/C. They have studied how the concentrations of urotropin, sodium chloride, and Fe/sup 3 +/ ions influence the protective properties of the seaweed inhibitor. They have made preliminary investigations of the mechanisms of the protective action.

  12. Cinnamic Acid Derivatives as Inhibitors of Oncogenic Protein Kinases--Structure, Mechanisms and Biomedical Effects.

    PubMed

    Mielecki, Marcin; Lesyng, Bogdan

    2016-01-01

    Cinnamic acid belongs to phenolic-acid class of polyphenols, one of the most abundant plant secondary metabolites. These substances are widely studied because of plethora of their biological activities. In particular, their inhibition of protein kinases contributes to the pleiotropic effects in the cell. Protein kinases are essential in controlling cell signaling networks. Selective targeting of oncogenic protein kinases increases clinical anticancer efficacy. Cinnamic acid and related compounds have inspired researchers in the design of numerous synthetic and semisynthetic inhibitors of oncogenic protein kinases for the past three decades. Interest in cinnamoyl-scaffold-containing compounds revived in recent years, which was stimulated by modern drug design and discovery methodologies such as in vitro and in silico HTS. This review presents cinnamic acid derivatives and analogs for which direct inhibition of protein kinases was identified. We also summarize significance of the above protein kinase families - validated or promising targets for anticancer therapies. The inhibition mode may vary from ATP-competitive, through bisubstrate-competitive and mixedcompetitive, to non-competitive one. Kinase selectivity is often correlated with subtle chemical modifications, and may also be steered by an additional non-cinnamoyl fragment of the inhibitor. Specific cinnamic acid congeners may synergize their effects in the cell by a wider range of activities, like suppression of additional enzymes, e.g. deubiquitinases, influencing the same signaling pathways (e.g. JAK2/STAT). Cinnamic acid, due to its biological and physicochemical properties, provides nature-inspired ideas leading to novel inhibitors of oncogenic protein kinases and related enzymes, capable to target a variety of cancer cells.

  13. How polyamine synthesis inhibitors and cinnamic acid affect tropane alkaloid production.

    PubMed

    Marconi, Patricia L; Alvarez, María A; Pitta-Alvarez, Sandra I

    2007-01-01

    Hairy roots of Brugmansia candida produce the tropane alkaloids scopolamine and hyoscyamine. In an attempt to divert the carbon flux from competing pathways and thus enhance productivity, the polyamine biosynthesis inhibitors cyclohexylamine (CHA) and methylglyoxal-bis-guanylhydrazone (MGBG) and the phenylalanine-ammonia-lyase inhibitor cinnamic acid were used. CHA decreased the specific productivity of both alkaloids but increased significantly the release of scopolamine (approx 500%) when it was added in the mid-exponential phase. However, when CHA was added for only 48 h during the exponential phase, the specific productivity of both alkaloids increased (approx 200%), favoring scopolamine. Treatment with MGBG was detrimental to growth but promoted release into the medium of both alkaloids. However, when it was added for 48 h during the exponential phase, MGBG increased the specific productivity (approx 200%) and release (250- 1800%) of both alkaloids. Cinnamic acid alone also favored release but not specific productivity. When a combination of CHA or MGBG with cinnamic acid was used, the results obtained were approximately the same as with each polyamine biosynthesis inhibitor alone, although to a lesser extent. Regarding root morphology, CHA inhibited growth of primary roots and ramification. However, it had a positive effect on elongation of lateral roots. PMID:17416978

  14. Largazole, a class I histone deacetylase inhibitor, enhances TNF-α-induced ICAM-1 and VCAM-1 expression in rheumatoid arthritis synovial fibroblasts

    SciTech Connect

    Ahmed, Salahuddin; Riegsecker, Sharayah; Beamer, Maria; Rahman, Ayesha; Bellini, Joseph V.; Bhansali, Pravin; Tillekeratne, L.M. Viranga

    2013-07-15

    In the present study, we evaluated the effect of largazole (LAR), a marine-derived class I HDAC inhibitor, on tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and matrix metalloproteinase-2 (MMP-2) activity. LAR (1–5 μM) had no adverse effect on the viability of RA synovial fibroblasts. Among the different class I HDACs screened, LAR (0.5–5 μM) inhibited the constitutive expression of HDAC1 (0–30%). Surprisingly, LAR increased class II HDAC [HDAC6] by ∼ 220% with a concomitant decrease in HDAC5 [30–58%] expression in RA synovial fibroblasts. SAHA (5 μM), a pan-HDAC inhibitor, also induced HDAC6 expression in RA synovial fibroblasts. Pretreatment of RA synovial fibroblasts with LAR further enhanced TNF-α-induced ICAM-1 and VCAM-1 expression. However, LAR inhibited TNF-α-induced MMP-2 activity in RA synovial fibroblasts by 35% when compared to the TNF-α-treated group. Further, the addition of HDAC6 specific inhibitor Tubastatin A with LAR suppressed TNF-α + LAR-induced ICAM-1 and VCAM-1 expression and completely blocked MMP-2 activity, suggesting a role of HDAC6 in LAR-induced ICAM-1 and VCAM-1 expression. LAR also enhanced TNF-α-induced phospho-p38 and phospho-AKT expression, but inhibited the expression of phospho-JNK and nuclear translocation of NF-κBp65 in RA synovial fibroblasts. These results suggest that LAR activates p38 and Akt pathways and influences class II HDACs, in particular HDAC6, to enhance some of the detrimental effects of TNF-α in RA synovial fibroblasts. Understanding the exact role of different HDAC isoenzymes in RA pathogenesis is extremely important in order to develop highly effective HDAC inhibitors for the treatment of RA. - Highlights: • Largazole enhances TNF-α-induced ICAM-1 and VCAM-1. • Largazole upregulates class II HDAC (HDAC6) in RA synovial fibroblasts. • Largazole also induces the expression of phospho-p38

  15. Suberoylanilide Hydroxamic Acid Restores Estrogen Reduced-cTnI Expression in Neonatal Hearts of Mice.

    PubMed

    Peng, Chang; Luo, Xiaomei; Xing, Qianlu; Sun, Huichao; Huang, Xupei

    2016-10-01

    Diastolic cardiac dysfunction can be caused by abnormality in cTnI expression during cardiogenesis. In this study, we investigated the effects of estrogen on the abnormal expression of cTnI in the hearts of neonatal mice and its potential epigenetic mechanisms. We then evaluated suberoylanilide hydroxamic acid (SAHA), a HDAC inhibitor, as a new target treatment of diastolic cardiac dysfunction. Postnatal day 0.5 C57BL/6 mice were injected with estrogen for 1 week, then the hearts of 7-day-old neonatal mice were retrieved for examination. The activities of HDAC and HAT were assayed by colorimetry, and the interaction of cTnI with HDAC5 in mice hearts were examined using chromatin immunoprecipitation assays. The expression of cTnI was tested by quantitative real-time RT-PCR and Western blot. Estrogen treated groups displayed a significantly increased HDAC activity in the hearts of neonatal mice while HAT activity remained unchanged. Additionally, HDAC5 was higher at the cTnI promoter, as compared to the saline treated control groups. The acetylation of histone H3K9ac on cTnI promoter significantly decreased in the hearts of neonatal mice treated with estrogen, and the expression of cTnI at transcriptional and protein levels also decreased. SAHA was shown to increase the acetylation of histone H3K9ac and upregulate the expression of cTnI. The data demonstrated that SAHA can correct cTnI expression abnormality caused by estrogen through inhibiting the binding of HDAC5 to the promoter of cTnI. J. Cell. Biochem. 117: 2377-2384, 2016. © 2016 Wiley Periodicals, Inc. PMID:27379430

  16. [Cyclooxygenase inhibitors in some dietary vegetables inhibit platelet aggregation function induced by arachidonic acid].

    PubMed

    Wang, Xin-Hua; Shao, Dong-Hua; Liang, Guo-Wei; Zhang, Ru; Xin, Qin; Zhang, Tao; Cao, Qing-Yun

    2011-10-01

    The study was purposed to investigate whether the cyclooxygenase inhibitors from some dietary vegetables can inhibit platelet aggregation function by the arachidonic acid (AA). The vegetable juice was mixed with platelet rich plasma (PRP), and asprin was used as positive control. The maximum ratio of platelet aggregation induced by AA was measured on the aggregometer; heme and cyclooxygenase-1 (COX(1)) or cyclooxygenase-2 (COX(2)) were added to test tubes containing COX reaction buffer, the mixture was vortex-mixed and exposed to aspirin or vegetable juice, followed by addition of AA and then hydrochloric acid (1 mol/L) was added to stop the COX reaction, followed by chemical reduction with stannous chloride solution. The concentration of COX inhibitors was detected by the enzyme immunoassay kit; vegetable juice (aspirin as positive control) was mixed with whole blood, which was followed by the addition of AA, and then the reaction was stopped by adding indomethacin, centrifuged, then the supernatant was collected, and the plasma thromboxane B(2) (TXB(2)) was measured by radioimmunoassay. The results showed that spinach juice, garlic bolt juice, blanched garlic leave juice and Chinese leek juice could inhibit by 80% human platelet aggregation induced by AA. 4 kinds of vegetables were all found a certain amount of cyclooxygenase inhibitors, which COX(1) and COX(2) inhibitor concentrations of spinach were higher than that of aspirin; 4 vegetable juice could significantly reduce the human plasma concentrations of TXB(2) induced by AA (p < 0.05). It is concluded that 4 kinds of raw vegetables containing cyclooxygenase inhibitors inhibit the production of TXA(2) and thus hinder platelet aggregation. Raw spinach, garlic bolt, blanched garlic and chinese leek inhibit significantly AA-induced human platelet aggregation in vitro. 4 kinds of vegetables may have a good potential perspective of anti-platelet aggregation therapy or prevention of thrombosis.

  17. The antiviral drug acyclovir is a slow-binding inhibitor of (D)-amino acid oxidase.

    PubMed

    Katane, Masumi; Matsuda, Satsuki; Saitoh, Yasuaki; Sekine, Masae; Furuchi, Takemitsu; Koyama, Nobuhiro; Nakagome, Izumi; Tomoda, Hiroshi; Hirono, Shuichi; Homma, Hiroshi

    2013-08-20

    d-Amino acid oxidase (DAO) is a degradative enzyme that is stereospecific for d-amino acids, including d-serine and d-alanine, which are believed to be coagonists of the N-methyl-d-aspartate (NMDA) receptor. To identify a new class of DAO inhibitor(s) that can be used to elucidate the molecular details of the active site environment of DAO, manifold biologically active compounds of microbial origin and pre-existing drugs were screened for their ability to inhibit DAO activity, and several compounds were identified as candidates. One of these compounds, acyclovir (ACV), a well-known antiviral drug used for the treatment of herpesvirus infections, was characterized and evaluated as a novel DAO inhibitor in vitro. Analysis showed that ACV acts on DAO as a reversible slow-binding inhibitor, and interestingly, the time required to achieve equilibrium between DAO, ACV, and the DAO/ACV complex was highly dependent on temperature. The binding mechanism of ACV to DAO was investigated in detail by several approaches, including kinetic analysis, structural modeling of DAO complexed with ACV, and site-specific mutagenesis of an active site residue postulated to be involved in the binding of ACV. The results confirm that ACV is a novel, active site-directed inhibitor of DAO that can be a valuable tool for investigating the structure-function relationships of DAO, including the molecular details of the active site environment of DAO. In particular, it appears that ACV can serve as an active site probe to study the structural basis of temperature-induced conformational changes of DAO.

  18. Discovery of the First N-Hydroxycinnamamide-Based Histone Deacetylase 1/3 Dual Inhibitors with Potent Oral Antitumor Activity

    PubMed Central

    2015-01-01

    In our previous study, we designed and synthesized a novel series of N-hydroxycinnamamide-based HDAC inhibitors (HDACIs), among which the representative compound 14a exhibited promising HDACs inhibition and antitumor activity. In this current study, we report the development of a more potent class of N-hydroxycinnamamide-based HDACIs, using 14a as lead, among which, compound 11r gave IC50 values of 11.8, 498.1, 3.9, 2000.8, 5700.4, 308.2, and 900.4 nM for the inhibition of HDAC1, HDAC2, HDAC3, HDAC8, HDAC4, HDAC6, and HDAC11, exhibiting dual HDAC1/3 selectivity. Compounds 11e, 11r, 11w, and 11y showed excellent growth inhibition in multiple tumor cell lines. In vivo antitumor assay in U937 xenograft model identified compound 11r as a potent, orally active HDACI. To the best of our knowledge, this work constitutes the first report of oral active N-hydroxycinnamamide-based HDACIs with dual HDAC1/3 selectivity. PMID:24694055

  19. Zoledronic acid cooperates with a cyclooxygenase-2 inhibitor and gefitinib in inhibiting breast and prostate cancer.

    PubMed

    Melisi, Davide; Caputo, Rosa; Damiano, Vincenzo; Bianco, Roberto; Veneziani, Bianca Maria; Bianco, A Raffaele; De Placido, Sabino; Ciardiello, Fortunato; Tortora, Giampaolo

    2005-12-01

    Biphosphonates (BPs) are widely used to inhibit osteoclastic activity in malignant diseases such as bone metastatic breast and prostate carcinoma. Recent studies reported that BPs could also cause a direct antitumor effect, probably due to their ability to interfere with several intracellular signalling molecules. The enzyme cyclooxygenase-2 (COX-2) and the epidermal growth factor receptor (EGFR) play an important role in the control of cancer cell growth and inhibitors of COX-2 and EGFR have shown antitumor activity in vitro and in vivo in several tumor types. We, and others, have previously shown that EGFR and COX-2 may be directly related to each other and that their selective inhibitors may have a cooperative effect. In the present study we have evaluated the combined effect of zoledronic acid, the most potent nitrogen-containing BP, with the COX-2 inhibitor SC-236 and the selective EGFR-tyrosine kinase inhibitor gefitinib, on breast and prostate cancer models in vitro and in xenografted nude mice. We show that combination of zoledronic acid with SC-236 and gefitinib causes a cooperative antitumor effect accompanied by induction of apoptosis and regulation of the expression of mitogenic factors, proangiogenic factors and cell cycle controllers both in vitro and in xenografted nude mice. The modulatory effect on protein expression and the inhibitory effect on tumor growth is much more potent when the three agents are used together. Since studies are ongoing to explore the antitumor effect of zoledronic acid, our results provide new insights into the mechanism of action of these agents and a novel rationale to translate this feasible combination treatment strategy into a clinical setting.

  20. Discovery of novel, non-acidic mPGES-1 inhibitors by virtual screening with a multistep protocol

    PubMed Central

    Noha, Stefan M.; Fischer, Katrin; Koeberle, Andreas; Garscha, Ulrike; Werz, Oliver; Schuster, Daniela

    2015-01-01

    Microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitors are considered as potential therapeutic agents for the treatment of inflammatory pain and certain types of cancer. So far, several series of acidic as well as non-acidic inhibitors of mPGES-1 have been discovered. Acidic inhibitors, however, may have issues, such as loss of potency in human whole blood and in vivo, stressing the importance of the design and identification of novel, non-acidic chemical scaffolds of mPGES-1 inhibitors. Using a multistep virtual screening protocol, the Vitas-M compound library (∼1.3 million entries) was filtered and 16 predicted compounds were experimentally evaluated in a biological assay in vitro. This approach yielded two molecules active in the low micromolar range (IC50 values: 4.5 and 3.8 μM, respectively). PMID:26088337

  1. Suppression of asymmetric acid efflux and gravitropism in maize roots treated with auxin transport inhibitors of sodium orthovanadate

    NASA Technical Reports Server (NTRS)

    Mulkey, T. J.; Evans, M. L.

    1982-01-01

    In gravitropically stimulated roots of maize (Zea mays L., hybrid WF9 x 38MS), there is more acid efflux on the rapidly growing upper side than on the slowly growing lower side. In light of the Cholodny/Went hypothesis of gravitropism which states that gravitropic curvature results from lateral redistribution of auxin, the effects of auxin transport inhibitors on the development of acid efflux asymmetry and curvature in gravistimulated roots were examined. All the transport inhibitors tested prevented both gravitropism and the development of asymmetric acid efflux in gravistimulated roots. The results indicate that auxin redistribution may cause the asymmetry of acid efflux, a finding consistent with the Cholodny/Went hypothesis of gravitropism. As further evidence that auxin-induced acid efflux asymmetry may mediate gravitropic curvature, sodium orthovanadate, an inhibitor of auxin-induced H+ efflux was found to prevent both gravitropism and the development of asymmetric acid efflux in gravistimulated roots.

  2. Histone deacetylase inhibitors and cell death

    PubMed Central

    Zhang, Jing; Zhong, Qing

    2014-01-01

    Histone deacetylases (HDACs) are a vast family of enzymes involved in chromatin remodeling and have crucial roles in numerous biological processes, largely through their repressive influence on transcription. In addition to modifying histones, HDACs also target many other non-histone protein substrates to regulate gene expression. Recently, HDACs have gained growing attention as HDAC-inhibiting compounds are being developed as promising cancer therapeutics. Histone deacetylase inhibitors (HDACi) have been shown to induce differentiation, cell cycle arrest, apoptosis, autophagy and necrosis in a variety of transformed cell lines. In this review, we mainly discuss how HDACi may elicit a therapeutic response to human cancers through different cell death pathways, in particular, apoptosis and autophagy. PMID:24898083

  3. Anaerobic microbial community response to methanogenic inhibitors 2-bromoethanesulfonate and propynoic acid.

    PubMed

    Webster, Tara M; Smith, Adam L; Reddy, Raghav R; Pinto, Ameet J; Hayes, Kim F; Raskin, Lutgarde

    2016-08-01

    Methanogenic inhibitors are often used to study methanogenesis in complex microbial communities or inhibit methanogens in the gastrointestinal tract of livestock. However, the resulting structural and functional changes in archaeal and bacterial communities are poorly understood. We characterized microbial community structure and activity in mesocosms seeded with cow dung and municipal wastewater treatment plant anaerobic digester sludge after exposure to two methanogenic inhibitors, 2-bromoethanesulfonate (BES) and propynoic acid (PA). Methane production was reduced by 89% (0.5 mmol/L BES), 100% (10 mmol/LBES), 24% (0.1 mmol/LPA), and 95% (10 mmol/LPA). Using modified primers targeting the methyl-coenzyme M reductase (mcrA) gene, changes in mcrA gene expression were found to correspond with changes in methane production and the relative activity of methanogens. Methanogenic activity was determined by the relative abundance of methanogen 16S rRNA cDNA as a percentage of the total community 16S rRNA cDNA. Overall, methanogenic activity was lower when mesocosms were exposed to higher concentrations of both inhibitors, and aceticlastic methanogens were inhibited to a greater extent than hydrogenotrophic methanogens. Syntrophic bacterial activity, measured by 16S rRNA cDNA, was also reduced following exposure to both inhibitors, but the overall structure of the active bacterial community was not significantly affected. PMID:26987552

  4. Chemical Genetics Uncovers Novel Inhibitors of Lignification, Including p-Iodobenzoic Acid Targeting CINNAMATE-4-HYDROXYLASE.

    PubMed

    Van de Wouwer, Dorien; Vanholme, Ruben; Decou, Raphaël; Goeminne, Geert; Audenaert, Dominique; Nguyen, Long; Höfer, René; Pesquet, Edouard; Vanholme, Bartel; Boerjan, Wout

    2016-09-01

    Plant secondary-thickened cell walls are characterized by the presence of lignin, a recalcitrant and hydrophobic polymer that provides mechanical strength and ensures long-distance water transport. Exactly the recalcitrance and hydrophobicity of lignin put a burden on the industrial processing efficiency of lignocellulosic biomass. Both forward and reverse genetic strategies have been used intensively to unravel the molecular mechanism of lignin deposition. As an alternative strategy, we introduce here a forward chemical genetic approach to find candidate inhibitors of lignification. A high-throughput assay to assess lignification in Arabidopsis (Arabidopsis thaliana) seedlings was developed and used to screen a 10-k library of structurally diverse, synthetic molecules. Of the 73 compounds that reduced lignin deposition, 39 that had a major impact were retained and classified into five clusters based on the shift they induced in the phenolic profile of Arabidopsis seedlings. One representative compound of each cluster was selected for further lignin-specific assays, leading to the identification of an aromatic compound that is processed in the plant into two fragments, both having inhibitory activity against lignification. One fragment, p-iodobenzoic acid, was further characterized as a new inhibitor of CINNAMATE 4-HYDROXYLASE, a key enzyme of the phenylpropanoid pathway synthesizing the building blocks of the lignin polymer. As such, we provide proof of concept of this chemical biology approach to screen for inhibitors of lignification and present a broad array of putative inhibitors of lignin deposition for further characterization. PMID:27485881

  5. Select microtubule inhibitors increase lysosome acidity and promote lysosomal disruption in acute myeloid leukemia (AML) cells.

    PubMed

    Bernard, Dannie; Gebbia, Marinella; Prabha, Swayam; Gronda, Marcela; MacLean, Neil; Wang, Xiaoming; Hurren, Rose; Sukhai, Mahadeo A; Cho, Eunice E; Manolson, Morris F; Datti, Alessandro; Wrana, Jeffrey; Minden, Mark D; Al-Awar, Rima; Aman, Ahmed; Nislow, Corey; Giaever, Guri; Schimmer, Aaron D

    2015-07-01

    To identify new biological vulnerabilities in acute myeloid leukemia, we screened a library of natural products for compounds cytotoxic to TEX leukemia cells. This screen identified the novel small molecule Deoxysappanone B 7,4' dimethyl ether (Deox B 7,4), which possessed nanomolar anti-leukemic activity. To determine the anti-leukemic mechanism of action of Deox B 7,4, we conducted a genome-wide screen in Saccharomyces cerevisiae and identified enrichment of genes related to mitotic cell cycle as well as vacuolar acidification, therefore pointing to microtubules and vacuolar (V)-ATPase as potential drug targets. Further investigations into the mechanisms of action of Deox B 7,4 and a related analogue revealed that these compounds were reversible microtubule inhibitors that bound near the colchicine site. In addition, Deox B 7,4 and its analogue increased lysosomal V-ATPase activity and lysosome acidity. The effects on microtubules and lysosomes were functionally important for the anti-leukemic effects of these drugs. The lysosomal effects were characteristic of select microtubule inhibitors as only the Deox compounds and nocodazole, but not colchicine, vinca alkaloids or paclitaxel, altered lysosome acidity and induced lysosomal disruption. Thus, our data highlight a new mechanism of action of select microtubule inhibitors on lysosomal function. PMID:25832785

  6. Repeated treatment with electroconvulsive seizures induces HDAC2 expression and down-regulation of NMDA receptor-related genes through histone deacetylation in the rat frontal cortex.

    PubMed

    Park, Hong Geun; Yu, Hyun Sook; Park, Soyoung; Ahn, Yong Min; Kim, Yong Sik; Kim, Se Hyun

    2014-09-01

    The enzymatic activity of histone deacetylases (HDACs) leads to a histone deacetylation-mediated condensed chromatic structure, resulting in transcriptional repression, which has been implicated in the modifications of neural circuits and behaviors. Repeated treatment with electroconvulsive seizure (ECS) induces changes in histone acetylation, expression of various genes, and intrabrain cellular changes, including neurogenesis. In this study, we examined the effects of repeated ECS on the expression of class I HDACs and related changes in histone modifications and gene expression in the rat frontal cortex. Ten days of repeated ECS treatments (E10X) up-regulated HDAC2 expression at the mRNA and protein levels in the rat frontal cortex compared with sham-treated controls; this was evident in the nuclei of neuronal cells in the prefrontal, cingulate, orbital, and insular cortices. Among the known HDAC2 target genes, mRNA expression of N-methyl-d-aspartate (NMDA) receptor signaling-related genes, including early growth response-1 (Egr1), c-Fos, glutamate receptor, ionotropic, N-methyl d-aspartate 2A (Nr2a), Nr2b, neuritin1 (Nrn1), and calcium/calmodulin-dependent protein kinase II alpha (Camk2α), were decreased, and the histone acetylation of H3 and/or H4 proteins was also reduced by E10X. Chromatin immunoprecipitation analysis revealed that HDAC2 occupancy in the promoters of down-regulated genes was increased significantly. Moreover, administration of sodium butyrate, a HDAC inhibitor, during the course of E10X ameliorated the ECS-induced down-regulation of genes in the rat frontal cortex. These findings suggest that induction of HDAC2 by repeated ECS treatment could play an important role in the down-regulation of NMDA receptor signaling-related genes in the rat frontal cortex through histone modification. PMID:24606669

  7. Histone Deacetylase 3 (HDAC3)-dependent Reversible Lysine Acetylation of Cardiac Myosin Heavy Chain Isoforms Modulates Their Enzymatic and Motor Activity.

    PubMed

    Samant, Sadhana A; Pillai, Vinodkumar B; Sundaresan, Nagalingam R; Shroff, Sanjeev G; Gupta, Mahesh P

    2015-06-19

    Reversible lysine acetylation is a widespread post-translational modification controlling the activity of proteins in different subcellular compartments. We previously demonstrated that a class II histone deacetylase (HDAC), HDAC4, and a histone acetyltransferase, p300/CREB-binding protein-associated factor, associate with cardiac sarcomeres and that a class I and II HDAC inhibitor, trichostatin A, enhances contractile activity of myofilaments. In this study we show that a class I HDAC, HDAC3, is also present at cardiac sarcomeres. By immunohistochemical and electron microscopic analyses, we found that HDAC3 was localized to A-band of sarcomeres and capable of deacetylating myosin heavy chain (MHC) isoforms. The motor domains of both cardiac α- and β-MHC isoforms were found to be reversibly acetylated. Biomechanical studies revealed that lysine acetylation significantly decreased the Km for the actin-activated ATPase activity of MHC isoforms. By in vitro motility assay, we found that lysine acetylation increased the actin-sliding velocity of α-myosin by 20% and β-myosin by 36% compared with their respective non-acetylated isoforms. Moreover, myosin acetylation was found to be sensitive to cardiac stress. During induction of hypertrophy, myosin isoform acetylation increased progressively with duration of stress stimuli independently of isoform shift, suggesting that lysine acetylation of myosin could be an early response of myofilaments to increase contractile performance of the heart. These studies provide the first evidence for localization of HDAC3 at myofilaments and uncover a novel mechanism modulating the motor activity of cardiac MHC isoforms.

  8. Histone deacetylase inhibitors attenuate P-aIgA1-induced cell proliferation and extracellular matrix synthesis in human renal mesangial cells in vitro

    PubMed Central

    Dai, Qin; Liu, Jian; Du, Yun-lei; Hao, Xu; Ying, Ji; Tan, Yun; He, Li-qun; Wang, Wei-ming; Chen, Nan

    2016-01-01

    Aim: Aberrantly glycosylated IgA1 is a key factor in the pathogenesis of IgA nephropathy (IgAN). In this study we investigated the effects of aggregated IgA1 derived from IgAN patients (P-aIgA1) on human renal mesangial cells (HMCs) and the anti-proliferative and antifibrotic effects of histone deacetylase (HDAC) inhibitors in vitro. Methods: Three types of IgA1 were prepared, ie, N-IgA1 (IgA1 from healthy volunteers), P-IgA1 (IgA1 from IgAN patients), and P-aIgA1 (aggregated IgA1 from IgAN patients). The isolated IgA1 was heated for thermal polymerization. The proliferation of human renal mesangial cells (HMCs) were assessed using MTT assay. The expression levels of relevant proteins were examined using immunoblotting assays or immunohistochemistry. Results: P-aIgA1 (25–250 μg/mL) dose-dependently promoted the proliferation of HMCs, and markedly increased the protein levels of type I histone deacetylase (HDAC1, HDAC2 and HDAC8) in the cells. Both P-IgA1 and N-IgA1 were much weaker in stimulating cell proliferation and HDAC expression. P-aIgA1 (50 μg/mL) markedly increased the protein levels of Col1a1 and PAI-1, as well as pSmad2/3 and pStat3 in the cells. Pretreatment with the HDAC inhibitor trichostatin A (TSA, 250 nmol/L) or valproic acid (VPA, 400 μg/mL) partially reversed P-aIgA1-induced cell proliferation and extracellular matrix synthesis in HMCs. Conclusion: P-aIgA1 produces pro-proliferative and profibrotic actions in HMCs via upregulating the expression of HDACs, and subsequently activating TGF-β/Smad2/3 and Jak2/Stat3 signaling pathways. Both VPA and TSA attenuate P-aIgA1-induced cell proliferation and fibrosis in HMCs. PMID:26775659

  9. Enhancement of stress resilience through Hdac6-mediated regulation of glucocorticoid receptor chaperone dynamics

    PubMed Central

    Jochems, Jeanine; Teegarden, Sarah L; Chen, Yong; Boulden, Janette; Challis, Collin; Ben-Dor, Gabriel A; Kim, Sangwon F; Berton, Olivier

    2014-01-01

    Background Acetylation of Hsp90 regulates downstream hormone signaling via the glucocorticoid receptor (GR), but the role of this molecular mechanism in stress homeostasis remains poorly understood. We tested whether acetylation of Hsp90 in the brain predicts and modulates the behavioral sequelae of a mouse model of social stress. Methods Mice subjected to chronic social defeat stress (CSDS) were stratified into resilient and vulnerable subpopulations. HPA axis function was probed using a DEX/CRF test. Hsp90 acetylation, Hsp90-GR interactions and GR translocation were measured in the dorsal raphe nucleus (DRN). To manipulate Hsp90 acetylation, we pharmacologically inhibited Hdac6, a known deacetylase of Hsp90 or overexpressed a point-mutant that mimics the hyperacetylated state of Hsp90 at lysine K294 Results Lower acetylated Hsp90, higher GR-Hsp90 association and enhanced GR translocation were observed in DRN of vulnerable mice after CSDS. Administration of ACY-738, an Hdac6-selective inhibitor, led to Hsp90 hyperacetylation in brain and in neuronal culture. In cell-based assays, ACY-738 increased the relative association of Hsp90 with FKBP51 versus FKBP52 and inhibited hormone-induced GR translocation. This effect was replicated by overexpressing the acetylation-mimic point-mutant of Hsp90. In vivo, ACY-738 promoted resilience to CSDS and serotonin-selective viral overexpression of the acetylation-mimic mutant of Hsp90 in raphe neurons reproduced the behaviroral effect of ACY-738. Conclusions Hyperacetylation of Hsp90 is a predictor and causal molecular determinant of stress resilience in mice. Brain-penetrant Hdac6 inhibitors increase Hsp90 acetylation and modulate GR chaperone dynamics offering a promising strategy to curtail deleterious socioaffective effects of stress and glucocorticoids. PMID:25442004

  10. Novel quinolinonyl diketo acid derivatives as HIV-1 integrase inhibitors: design, synthesis, and biological activities.

    PubMed

    Di Santo, Roberto; Costi, Roberta; Roux, Alessandra; Miele, Gaetano; Crucitti, Giuliana Cuzzucoli; Iacovo, Alberto; Rosi, Federica; Lavecchia, Antonio; Marinelli, Luciana; Di Giovanni, Carmen; Novellino, Ettore; Palmisano, Lucia; Andreotti, Mauro; Amici, Roberta; Galluzzo, Clementina Maria; Nencioni, Lucia; Palamara, Anna Teresa; Pommier, Yves; Marchand, Christophe

    2008-08-14

    Novel quinolinonyl diketo acids were designed to obtain integrase (IN) inhibitors selectively active against the strand transfer (ST) step of the HIV integration process. Those new compounds are characterized by a single aryl diketo acid (DKA) chain in comparison to 4, a bifunctional diketo acid reported by our group as an anti-IN agent highly potent against both the 3'-processing and ST steps. Compound 6d was the most potent derivative in IN enzyme assays, while 6i showed the highest potency against HIV-1 in acutely infected cells. The selective inhibition of ST suggested the newly designed monofunctional DKAs bind the IN-DNA acceptor site without affecting the DNA donor site.

  11. [Prevention of colorectal cancer: acetylsalicyclic acid and cyclo-oxygenase-2 inhibitors are only partially effective].

    PubMed

    Kleibeuker, J H; de Vries, E G

    2003-11-01

    Acetylsalicylic acid was recently shown to inhibit the development of colorectal adenomas in subjects with a moderately increased risk for colorectal cancer. The mechanisms by which acetylsalicylic acid and other NSAIDs, including COX-2 inhibitors, exert this effect include: inhibition of COX-2, induction of apoptosis and induction of the P21 protein that controls the development of crypt cells. For the majority of the population, a healthy lifestyle and healthy eating habits are the best means of preventing colorectal cancer. In addition, population-wide screening should be encouraged. For people with an increased risk of colorectal cancer, acetylsalicylic acid only has a partial effect and therefore endoscopic surveillance is still indicated. Sulindac or celecoxib may be useful for patients with familial adenomatous polyposis and in particular for inhibiting the development of rectal adenomas after subtotal colectomy with ileorectal anastomosis. However, in these cases endoscopic surveillance is also still necessary.

  12. Discovery of wall teichoic acid inhibitors as potential anti-MRSA β-lactam combination agents.

    PubMed

    Wang, Hao; Gill, Charles J; Lee, Sang H; Mann, Paul; Zuck, Paul; Meredith, Timothy C; Murgolo, Nicholas; She, Xinwei; Kales, Susan; Liang, Lianzhu; Liu, Jenny; Wu, Jin; Santa Maria, John; Su, Jing; Pan, Jianping; Hailey, Judy; Mcguinness, Debra; Tan, Christopher M; Flattery, Amy; Walker, Suzanne; Black, Todd; Roemer, Terry

    2013-02-21

    Innovative strategies are needed to combat drug resistance associated with methicillin-resistant Staphylococcus aureus (MRSA). Here, we investigate the potential of wall teichoic acid (WTA) biosynthesis inhibitors as combination agents to restore β-lactam efficacy against MRSA. Performing a whole-cell pathway-based screen, we identified a series of WTA inhibitors (WTAIs) targeting the WTA transporter protein, TarG. Whole-genome sequencing of WTAI-resistant isolates across two methicillin-resistant Staphylococci spp. revealed TarG as their common target, as well as a broad assortment of drug-resistant bypass mutants mapping to earlier steps of WTA biosynthesis. Extensive in vitro microbiological analysis and animal infection studies provide strong genetic and pharmacological evidence of the potential effectiveness of WTAIs as anti-MRSA β-lactam combination agents. This work also highlights the emerging role of whole-genome sequencing in antibiotic mode-of-action and resistance studies.

  13. Docking analysis of gallic acid derivatives as HIV-1 protease inhibitors.

    PubMed

    Singh, Anjali; Pal, Tapan Kumar

    2015-01-01

    HIV-1 Protease (HIV-1 PR) enzymes are essential for accurate assembly and maturation of infectious HIV retroviruses. The significant role of HIV-1 protease in viral replication has made it a potential drug target. In the recent past, phytochemical Gallic Acid (GA) derivatives have been screened for protease inhibitor activity. The present work aims to design and evaluate potential GA-based HIV-1 PR phytoinhibitors by docking approach. The ligands were prepared by ChemDraw and docking was performed in HEX software. In this present study, one of the GA analogues (GA4) emerged as a potent drug candidate for HIV-1 PR inhibition, and docking results showed it to be comparable with anti-HIV drugs, darunavir and amprenavir. The GA4 derivative provided a lead for designing more effective HIV-1 PR inhibitors.

  14. Fatty acid synthase inhibitors of phenolic constituents isolated from Garcinia mangostana.

    PubMed

    Jiang, He Zhong; Quan, Xiao Fang; Tian, Wei Xi; Hu, Jiang Miao; Wang, Peng Cheng; Huang, Sheng Zhuo; Cheng, Zhong Quan; Liang, Wen Juan; Zhou, Jun; Ma, Xiao Feng; Zhao, You Xing

    2010-10-15

    Natural inhibitors of fatty acid synthase (FAS) are emerging as potential therapeutic agents to treat cancer and obesity. The bioassay-guided chemical investigation of the hulls of Garcinia mangostana led to the isolation of 13 phenolic compounds (1-13) mainly including xanthone and benzophenone, in which compounds 7, 8, 9, 10, and 11 were isolated from this plant for the first time and compound 9 was a new natural product. These isolates possess strong inhibitory activity of FAS with the IC(50) values ranging from 1.24 to 91.07 μM. The study indicates that two types of natural products, xanthones and benzophenones, could be considered as promising FAS inhibitors.

  15. Potent inhibitors of HCV-NS3 protease derived from boronic acids

    SciTech Connect

    Venkatraman, Srikanth; Wu, Wanli; Prongay, Andrew; Girijavallabhan, Viyyoor; Njoroge, F. George

    2009-07-23

    Chronic hepatitis C infection is the leading causes for cirrhosis of the liver and hepatocellular carcinoma, leading to liver failure and liver transplantation. The etiological agent, HCV virus produces a single positive strand of RNA that is processed with the help of serine protease NS3 to produce mature virus. Inhibition of NS3 protease can be potentially used to develop effective drugs for HCV infections. Numerous efforts are now underway to develop potent inhibitors of HCV protease that contain ketoamides as serine traps. Herein we report the synthesis of a series of potent inhibitors that contain a boronic acid as a serine trap. The activity of these compounds were optimized to 200 pM. X-ray structure of compound 17 bound to NS3 protease is also discussed.

  16. In Vivo PET-imaging of Histone Deacetylases by 18F-Suberoylanilide Hydroxamic Acid (18F-SAHA)1

    PubMed Central

    Hendricks, J. Adam; Keliher, Edmund J.; Marinelli, Brett; Reiner, Thomas; Weissleder, Ralph; Mazitschek, Ralph

    2011-01-01

    Histone deacetylases (HDACs) are a group of enzymes that modulate gene expression and cell state by deacetylation of both histone and non-histone proteins. A variety of HDAC inhibitors (HDACi) have already undergone clinical testing in cancer. Real-time in vivo imaging of HDACs and their inhibition would be invaluable; however, the development of appropriate imaging agents has remained a major challenge. Here, we describe the development and evaluation of 18F-suberoylanilide hydroxamic acid (18F-SAHA 1a), a close analog of the most clinically relevant HDACi, suberoylanilide hydroxamic acid (SAHA). We demonstrate that 1a has near identical biochemical activity profiles to SAHA, and report findings from pharmacokinetic studies. Using a murine ovarian cancer model, we likewise show that HDACi target binding efficacy can be quantitated within 24 hours of administration. 1a thus represents the first 18F-positron emission tomography (PET) HDAC imaging agent, which also exhibits low nanomolar potency and is pharmacologically analogous to a clinically relevant HDACi. PMID:21721525

  17. Discovery of arjunolic acid as a novel non-zinc binding carbonic anhydrase II inhibitor.

    PubMed

    Kalyanavenkataraman, Subhalakshmi; Nanjan, Pandurangan; Banerji, Asoke; Nair, Bipin G; Kumar, Geetha B

    2016-06-01

    Elevated levels of carbonic anhydrase II (CA II) have been shown to be associated with cardiac hypertrophy and heart failure. Although arjunolic acid (AA) has a diverse range of therapeutic applications including cardio-protection, there have been no reports on the effect of AA on CA II. The present study describes for the first time, the novel zinc independent inhibition of CA II by AA. The molecular docking studies of AA indicated that the hydroxyl group at C2 of the A-ring, which hydrogen bonds with the catalytic site residues (His64, Asn62 and Asn67), along with the gem-dimethyl group at C20 of the E-ring, greatly influences the inhibitory activity, independent of the catalytic zinc, unlike the inhibition observed with most CA II inhibitors. Among the triterpenoids tested viz. arjunolic acid, arjunic acid, asiatic acid, oleanolic acid and ursolic acid, AA was the most potent in inhibiting CA II in vitro with an IC50 of 9μM. It was interesting to note, that in spite of exhibiting very little differences in their structures, these triterpenoids exhibited vast differences in their inhibitory activities, with IC50 values ranging from 9μM to as high as 333μM. Furthermore, AA also inhibited the cytosolic activity of CA in H9c2 cardiomyocytes, as reflected by the decrease in acidification of the intracellular pH (pHi). The decreased acidification reduced the intracellular calcium levels, which further prevented the mitochondrial membrane depolarization. Thus, these studies provide a better understanding for establishing the novel molecular mechanism involved in CA II inhibition by the non-zinc binding inhibitor AA. PMID:27038848

  18. The intracellular Ca(2+)-pump inhibitors thapsigargin and cyclopiazonic acid induce stress proteins in mammalian chondrocytes.

    PubMed

    Cheng, T C; Benton, H P

    1994-07-15

    Primary cultures of mammalian articular chondrocytes respond to treatment with the intracellular Ca(2+)-pump inhibitors thapsigargin (TG) and cyclopiazonic acid by specific changes in protein synthesis consistent with a stress response. Two-dimensional gel electrophoresis of newly synthesized proteins confirmed that the response was consistent with the induction of glucose-regulated proteins. The effects of low-dose TG (10 nM), measured by changes in [35S]methionine labelling of newly synthesized proteins, can first be observed by 10 h and are maximal by 24 h. The pattern of changes induced by TG is shared with cyclopiazonic acid, but effects of both perturbants differ significantly from changes induced by heat shock. Upon removal of TG, normal protein synthesis is restored by 48 h. Immunoblots showed increased concentrations of the stress proteins HSP90, HSP72/73 and HSP60 in chondrocytes treated with TG, but induction of newly synthesized heat-shock proteins by TG was not apparent on [35S]methionine-labelled gels. The alterations in protein synthesis induced by Ca(2+)-pump inhibitors were unaffected by BAPTA-AM loading, which clamped cytosolic Ca2+ at resting levels. We conclude that inhibition of intracellular Ca(2+)-pump activity can elicit a stress response, which has important implications for the interpretation of chronic use of Ca(2+)-pump inhibitors. In particular, the activation of the cellular shock response should be considered in interpreting the regulation of protein synthesis and cell survival by Ca(2+)-pump inhibitors such as TG. PMID:8043004

  19. Angiotensin-converting enzyme inhibitors modulate kynurenic acid production in rat brain cortex in vitro.

    PubMed

    Zakrocka, Izabela; Turski, Waldemar A; Kocki, Tomasz

    2016-10-15

    It is well established that the renin-angiotensin system (RAS) is present in the brain and that glutamate activates the brain centers responsible for blood pressure control. An antagonist of glutamate, kynurenic acid (KYNA) was shown to decrease blood pressure after intracerebral administration. KYNA is an endogenous metabolite of tryptophan produced from the breakdown of kynurenine by kynurenine aminotransferases (KAT), mainly within astrocytes. The purpose of this study was to evaluate the influence of three angiotensin-converting enzyme inhibitors (lisinopril, perindopril and ramipril) on KYNA production and KAT activity in the rat brain cortex in vitro. The effect of the angiotensin-converting enzyme inhibitors on KYNA production was examined on rat brain cortical slices incubated for 2h in the presence of l-kynurenine and the angiotensin-converting enzyme inhibitors. To analyze KAT I and KAT II activity, brain cortical homogenates were incubated for 2h with L-kynurenine and the tested drugs. KYNA was separated by HPLC and quantified fluorometrically. Among the examined angiotensin-converting enzyme inhibitors, lisinopril increased KYNA production, perindopril was ineffective, and ramipril decreased KYNA synthesis in rat brain cortical slices. Lisinopril increased KAT I activity and perindopril did not affect it. However, ramipril lowered KAT I activity in rat brain cortex in vitro. Neither lisinopril nor perindopril affected KAT II activity, but ramipril decreased KAT II activity in the rat brain cortex in vitro. Our study reveals that angiotensin-converting enzyme inhibitors show various influences on KYNA production in rat brain cortical slices and activity of KATs.

  20. Solution structure of the squash aspartic acid proteinase inhibitor (SQAPI) and mutational analysis of pepsin inhibition.

    PubMed

    Headey, Stephen J; Macaskill, Ursula K; Wright, Michele A; Claridge, Jolyon K; Edwards, Patrick J B; Farley, Peter C; Christeller, John T; Laing, William A; Pascal, Steven M

    2010-08-27

    The squash aspartic acid proteinase inhibitor (SQAPI), a proteinaceous proteinase inhibitor from squash, is an effective inhibitor of a range of aspartic proteinases. Proteinaceous aspartic proteinase inhibitors are rare in nature. The only other example in plants probably evolved from a precursor serine proteinase inhibitor. Earlier work based on sequence homology modeling suggested SQAPI evolved from an ancestral cystatin. In this work, we determined the solution structure of SQAPI using NMR and show that SQAPI shares the same fold as a plant cystatin. The structure is characterized by a four-strand anti-parallel beta-sheet gripping an alpha-helix in an analogous manner to fingers of a hand gripping a tennis racquet. Truncation and site-specific mutagenesis revealed that the unstructured N terminus and the loop connecting beta-strands 1 and 2 are important for pepsin inhibition, but the loop connecting strands 3 and 4 is not. Using ambiguous restraints based on the mutagenesis results, SQAPI was then docked computationally to pepsin. The resulting model places the N-terminal strand of SQAPI in the S' side of the substrate binding cleft, whereas the first SQAPI loop binds on the S side of the cleft. The backbone of SQAPI does not interact with the pepsin catalytic Asp(32)-Asp(215) diad, thus avoiding cleavage. The data show that SQAPI does share homologous structural elements with cystatin and appears to retain a similar protease inhibitory mechanism despite its different target. This strongly supports our hypothesis that SQAPI evolved from an ancestral cystatin.

  1. Human THAP7 is a chromatin-associated, histone tail-binding protein that represses transcription via recruitment of HDAC3 and nuclear hormone receptor corepressor.

    PubMed

    Macfarlan, Todd; Kutney, Sara; Altman, Brian; Montross, Rebecca; Yu, Jiujiu; Chakravarti, Debabrata

    2005-02-25

    The identities of signal transducer proteins that integrate histone hypoacetylation and transcriptional repression are largely unknown. Here we demonstrate that THAP7, an uncharacterized member of the recently identified THAP (Thanatos-associated protein) family of proteins, is ubiquitously expressed, associates with chromatin, and represses transcription. THAP7 binds preferentially to hypoacetylated (un-, mono-, and diacetylated) histone H4 tails in vitro via its C-terminal 77 amino acids. Deletion of this domain, or treatment of cells with the histone deacetylase inhibitor TSA, which leads to histone hyperacetylation, partially disrupts THAP7/chromatin association in living cells. THAP7 coimmunoprecipitates with histone deacetylase 3 (HDAC3) and the nuclear hormone receptor corepressor (NCoR) and represses transcription as a Gal4 fusion protein. Chromatin immunoprecipitation assays demonstrate that these corepressors are recruited to promoters in a THAP7 dependent manner and promote histone H3 hypoacetylation. The conserved THAP domain is a key determinant for full HDAC3 association in vitro, and both the THAP domain and the histone interaction domain are important for the repressive properties of THAP7. Full repression mediated by THAP7 is also dependent on NCoR expression. We hypothesize that THAP7 is a dual function repressor protein that actively targets deacetylation of histone H3 necessary to establish transcriptional repression and functions as a signal transducer of the repressive mark of hypoacetylated histone H4. This is the first demonstration of the transcriptional regulatory properties of a human THAP domain protein, and a critical identification of a potential transducer of the repressive signal of hypoacetylated histone H4 in higher eukaryotes. PMID:15561719

  2. Synthesis and characterization of phosphocitric acid, a potent inhibitor of hydroxylapatite crystal growth.

    PubMed

    Tew, W P; Mahle, C; Benavides, J; Howard, J E; Lehninger, A L

    1980-04-29

    Human urine and extracts of rat liver mitochondria contain apparently identical agents capable of inhibiting the precipitation or crystallization of calcium phosphate. Its general properties, as well as 1H NMR and mass spectra, have suggested that the agent is phosphocitric acid. This paper reports the synthesis of phosphocitric acid via the phosphorylation of triethyl citrate with o-phenylene phosphochloridate, hydrogenolysis of the product to yield triethyl phosphocitrate, hydrolytic removal of the blocking ethyl groups and also chromatographic purification. An enzymatic assay of phosphocitrate is described. Synthetic phosphocitrate was found to be an exceedingly potent inhibitor of the growth of hydroxylapatite seed crystals in a medium supersaturated with respect to Ca2+ and phosphate. Comparative assays showed phosphocitrate to be much more potent than the most active precipitation-crystallization inhibitors previously reported, which include pyrophosphate and ATP. 14C-Labeled phosphocitrate was bound very tightly to hydroxylapatite crystals. Such binding appeared to be essential for its inhibitory activity on crystal growth. Citrate added before but not after, phosphocitrate greatly enhanced the inhibitory potency of the latter. This enhancement effect was not given by other tricarboxylic acids. The monoethyl ester of phosphocitrate had no inhibitory effect on hydroxylapatite crystal growth.

  3. Inhibition of Pig Phosphoenolpyruvate Carboxykinase Isoenzymes by 3-Mercaptopicolinic Acid and Novel Inhibitors.

    PubMed

    Hidalgo, Jorge; Latorre, Pedro; Carrodeguas, José Alberto; Velázquez-Campoy, Adrián; Sancho, Javier; López-Buesa, Pascual

    2016-01-01

    There exist two isoforms of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in pig populations that differ in a single amino acid (Met139Leu). The isoenzymes have different kinetic properties, affecting more strongly the Km and Vmax of nucleotides. They are associated to different phenotypes modifying traits of considerable economic interest. In this work we use inhibitors of phosphoenolpyruvate carboxykinase activity to search for further differences between these isoenzymes. On the one hand we have used the well-known inhibitor 3-mercaptopicolinic acid. Its inhibition patterns were the same for both isoenzymes: a three-fold decrease of the Ki values for GTP in 139Met and 139Leu (273 and 873 μM, respectively). On the other hand, through screening of a chemical library we have found two novel compounds with inhibitory effects of a similar magnitude to that of 3-mercaptopicolinic acid but with less solubility and specificity. One of these novel compounds, (N'1-({5-[1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-thienyl}methylidene)-2,4-dichlorobenzene-1-carbohydrazide), exhibited significantly different inhibitory effects on either isoenzyme: it enhanced threefold the apparent Km value for GTP in 139Met, whereas in 139Leu, it reduced it from 99 to 69 μM. The finding of those significant differences in the binding of GTP reinforces the hypothesis that the Met139Leu substitution affects strongly the nucleotide binding site of PEPCK-C.

  4. Inhibition of Pig Phosphoenolpyruvate Carboxykinase Isoenzymes by 3-Mercaptopicolinic Acid and Novel Inhibitors

    PubMed Central

    Hidalgo, Jorge; Latorre, Pedro; Carrodeguas, José Alberto; Velázquez-Campoy, Adrián; Sancho, Javier; López-Buesa, Pascual

    2016-01-01

    There exist two isoforms of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in pig populations that differ in a single amino acid (Met139Leu). The isoenzymes have different kinetic properties, affecting more strongly the Km and Vmax of nucleotides. They are associated to different phenotypes modifying traits of considerable economic interest. In this work we use inhibitors of phosphoenolpyruvate carboxykinase activity to search for further differences between these isoenzymes. On the one hand we have used the well-known inhibitor 3-mercaptopicolinic acid. Its inhibition patterns were the same for both isoenzymes: a three-fold decrease of the Ki values for GTP in 139Met and 139Leu (273 and 873 μM, respectively). On the other hand, through screening of a chemical library we have found two novel compounds with inhibitory effects of a similar magnitude to that of 3-mercaptopicolinic acid but with less solubility and specificity. One of these novel compounds, (N'1-({5-[1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-thienyl}methylidene)-2,4-dichlorobenzene-1-carbohydrazide), exhibited significantly different inhibitory effects on either isoenzyme: it enhanced threefold the apparent Km value for GTP in 139Met, whereas in 139Leu, it reduced it from 99 to 69 μM. The finding of those significant differences in the binding of GTP reinforces the hypothesis that the Met139Leu substitution affects strongly the nucleotide binding site of PEPCK-C. PMID:27391465

  5. Inhibition of Pig Phosphoenolpyruvate Carboxykinase Isoenzymes by 3-Mercaptopicolinic Acid and Novel Inhibitors.

    PubMed

    Hidalgo, Jorge; Latorre, Pedro; Carrodeguas, José Alberto; Velázquez-Campoy, Adrián; Sancho, Javier; López-Buesa, Pascual

    2016-01-01

    There exist two isoforms of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in pig populations that differ in a single amino acid (Met139Leu). The isoenzymes have different kinetic properties, affecting more strongly the Km and Vmax of nucleotides. They are associated to different phenotypes modifying traits of considerable economic interest. In this work we use inhibitors of phosphoenolpyruvate carboxykinase activity to search for further differences between these isoenzymes. On the one hand we have used the well-known inhibitor 3-mercaptopicolinic acid. Its inhibition patterns were the same for both isoenzymes: a three-fold decrease of the Ki values for GTP in 139Met and 139Leu (273 and 873 μM, respectively). On the other hand, through screening of a chemical library we have found two novel compounds with inhibitory effects of a similar magnitude to that of 3-mercaptopicolinic acid but with less solubility and specificity. One of these novel compounds, (N'1-({5-[1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-thienyl}methylidene)-2,4-dichlorobenzene-1-carbohydrazide), exhibited significantly different inhibitory effects on either isoenzyme: it enhanced threefold the apparent Km value for GTP in 139Met, whereas in 139Leu, it reduced it from 99 to 69 μM. The finding of those significant differences in the binding of GTP reinforces the hypothesis that the Met139Leu substitution affects strongly the nucleotide binding site of PEPCK-C. PMID:27391465

  6. Activity of cefazolin and two beta-lactamase inhibitors, clavulanic acid and sulbactam, against Bacteroides fragilis.

    PubMed Central

    Fekete, T; McGowen, J; Cundy, K R

    1987-01-01

    One hundred clinical isolates of the Bacteroides fragilis group of bacteria were tested by agar dilution for susceptibility to cefazolin alone or in combination with clavulanic acid or sulbactam. For cefazolin, the MIC for 50% of the isolates (MIC50) was 32 micrograms/ml, the breakpoint for susceptibility. With the addition of 0.5 micrograms of clavulanic acid per ml, the MIC for 90% of the isolates (MIC90) was 8 micrograms/ml, well within the achievable range of concentrations in serum or tissue. Similarly, with the addition of 0.5 micrograms of sulbactam per ml, the MIC90 was 16 micrograms/ml. The addition of a higher concentration (4.0 micrograms/ml) of clavulanic acid or sulbactam resulted in MIC90S which were fourfold lower than those with 0.5 micrograms/ml. A fixed ratio of cefazolin-beta-lactamase inhibitor of 4:1 resulted in an MIC50 and MIC90 which were intermediate between the 0.5- and 4.0-micrograms/ml fixed concentration of beta-lactamase inhibitor. PMID:3032097

  7. Characterization of Inhibitor-Resistant Histone Deacetylase Activity in Plant-Pathogenic Fungi

    PubMed Central

    Baidyaroy, Dipnath; Brosch, Gerald; Graessle, Stefan; Trojer, Patrick; Walton, Jonathan D.

    2002-01-01

    HC-toxin, a cyclic peptide made by the filamentous fungus Cochliobolus carbonum, is an inhibitor of histone deacetylase (HDAC) from many organisms. It was shown earlier that the HDAC activity in crude extracts of C. carbonum is relatively insensitive to HC-toxin as well as to the chemically unrelated HDAC inhibitors trichostatin and D85, whereas the HDAC activity of Aspergillus nidulans is sensitive (G. Brosch et al., Biochemistry 40:12855-12863, 2001). Here we report that HC-toxin-resistant HDAC activity was present in other, but not all, plant-pathogenic Cochliobolus species but not in any of the saprophytic species tested. The HDAC activities of the fungi Alternaria brassicicola and Diheterospora chlamydosporia, which also make HDAC inhibitors, were resistant. The HDAC activities of all C. carbonum isolates tested, except one non-toxin-producing isolate, were resistant. In a cross between a sensitive isolate and a resistant isolate, resistance genetically cosegregated with HC-toxin production. When fractionated by anion-exchange chromatography, extracts of resistant and sensitive isolates and species had two peaks of HDAC activity, one that was fully HC-toxin resistant and a second that was larger and sensitive. The first peak was consistently smaller in extracts of sensitive fungi than in resistant fungi, but the difference appeared to be insufficiently large to explain the differential sensitivities of the crude extracts. Differences in mRNA expression levels of the four known HDAC genes of C. carbonum did not account for the observed differences in HDAC activity profiles. When mixed together, resistant extracts protected extracts of sensitive C. carbonum but did not protect other sensitive Cochlibolus species or Neurospora crassa. Production of this extrinsic protection factor was dependent on TOXE, the transcription factor that regulates the HC-toxin biosynthetic genes. The results suggest that C. carbonum has multiple mechanisms of self-protection against

  8. Design, synthesis, and antitumor evaluation of histone deacetylase inhibitors with l-phenylglycine scaffold

    PubMed Central

    Zhang, Yingjie; Li, Xiaoguang; Hou, Jinning; Huang, Yongxue; Xu, Wenfang

    2015-01-01

    In our previous research, a novel series of histone deacetylase (HDAC) inhibitors with l-phenylglycine scaffold were designed and synthesized, among which amides D3 and D7 and ureido D18 were far superior to the positive control (suberoylanilide hydroxamic acid [SAHA]) in HDAC inhibition, but were only comparable to SAHA in antiproliferation on tumor cell lines. Herein, further structural derivation of lead compounds D3, D7, and D18 was carried out to improve their cellular activities. Most of our newly synthesized compounds exhibited more potent HDAC inhibitory activities than the positive control SAHA, and several derivatives were even better than their parent compounds. However, compared with SAHA and our lead compounds, only secondary amine series compounds exhibited improved antiproliferative activities, likely due to their appropriate topological polar surface area values and cell permeabilities. In a human histiocytic lymphoma (U937) xenograft model, the most potent secondary amine 9d exhibited similar in vivo antitumor activity to that of SAHA. PMID:26504374

  9. Benzimidazole as corrosion inhibitor for heat treated 6061 Al- SiCp composite in acetic acid

    NASA Astrophysics Data System (ADS)

    Chacko, Melby; Nayak, Jagannath

    2015-06-01

    6061 Al-SiCpcomposite was solutionizedat 350 °C for 30 minutes and water quenched. It was then underaged at 140 °C (T6 treatment). The aging behaviour of the composite was studied using Rockwell B hardness measurement. Corrosion behaviour of the underaged sample was studied in different concentrations of acetic acid and at different temperatures. Benzimidazole at different concentrations was used for the inhibition studies. Inhibition efficiency of benzimidazole was calculated for different experimental conditions. Thermodynamic parameters were found out which suggested benzimidazole is an efficient inhibitor and it adsorbed on to the surface of composite by mixed adsorption where chemisorption is predominant.

  10. Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

    PubMed

    Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

    2016-09-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and

  11. Discovery of Bacterial Fatty Acid Synthase Type II Inhibitors Using a Novel Cellular Bioluminescent Reporter Assay

    PubMed Central

    Wallace, Joselynn; Bowlin, Nicholas O.; Mills, Debra M.; Saenkham, Panatda; Kwasny, Steven M.; Opperman, Timothy J.; Williams, John D.; Rock, Charles O.; Bowlin, Terry L.

    2015-01-01

    Novel, cellular, gain-of-signal, bioluminescent reporter assays for fatty acid synthesis type II (FASII) inhibitors were constructed in an efflux-deficient strain of Pseudomonas aeruginosa and based on the discovery that FASII genes in P. aeruginosa are coordinately upregulated in response to pathway disruption. A screen of 115,000 compounds identified a series of sulfonamidobenzamide (SABA) analogs, which generated strong luminescent signals in two FASII reporter strains but not in four control reporter strains designed to respond to inhibitors of pathways other than FASII. The SABA analogs selectively inhibited lipid biosynthesis in P. aeruginosa and exhibited minimal cytotoxicity to mammalian cells (50% cytotoxic concentration [CC50] ≥ 80 μM). The most potent SABA analogs had MICs of 0.5 to 7.0 μM (0.2 to 3.0 μg/ml) against an efflux-deficient Escherichia coli (ΔtolC) strain but had no detectable MIC against efflux-proficient E. coli or against P. aeruginosa (efflux deficient or proficient). Genetic, molecular genetic, and biochemical studies revealed that SABA analogs target the enzyme (AccC) catalyzing the biotin carboxylase half-reaction of the acetyl coenzyme A (acetyl-CoA) carboxylase step in the initiation phase of FASII in E. coli and P. aeruginosa. These results validate the capability and the sensitivity of this novel bioluminescent reporter screen to identify inhibitors of E. coli and P. aeruginosa FASII. PMID:26169404

  12. Induction of aromatic-L-amino acid decarboxylase by decarboxylase inhibitors in idiopathic parkinsonism.

    PubMed

    Boomsma, F; Meerwaldt, J D; Man in 't Veld, A J; Hovestadt, A; Schalekamp, M A

    1989-06-01

    We evaluated the effect of administration of L-dopa, alone or in combination with a peripheral decarboxylase inhibitor, on plasma levels of aromatic-L-amino acid decarboxylase (ALAAD). After single-dose administration of L-dopa plus benserazide (Madopar) in healthy subjects and in chronically treated patients with parkinsonism, plasma ALAAD followed for 2 to 3 hours fell, but returned to predosing levels within 90 minutes. Four groups of patients with idiopathic parkinsonism were studied during chronic treatment: Group I, no L-dopa treatment (n = 31); Group II, L-dopa alone (n = 15); Group III, L-dopa plus benserazide (n = 28); and Group IV, L-dopa plus carbidopa (Sinemet, n = 30). Plasma ALAAD 2 hours after dosing was normal in Groups I and II. ALAAD was increased threefold in Groups III and IV, suggesting induction of ALAAD by the coadministration of a peripheral decarboxylase inhibitor. In a study of 3 patients in whom L-dopa/benserazide was started, plasma ALAAD rose gradually over 3 to 4 weeks. Further detailed pharmacokinetic studies of L-dopa, dopamine, and ALAAD in plasma and cerebrospinal fluid are required to determine if the apparent ALAAD induction by a peripheral decarboxylase inhibitor may be related to the loss of clinical efficacy of combination therapy in some patients and how it is related to end-of-dose deterioration and on-off phenomena. PMID:2742363

  13. Induction of aromatic-L-amino acid decarboxylase by decarboxylase inhibitors in idiopathic parkinsonism.

    PubMed

    Boomsma, F; Meerwaldt, J D; Man in 't Veld, A J; Hovestadt, A; Schalekamp, M A

    1989-06-01

    We evaluated the effect of administration of L-dopa, alone or in combination with a peripheral decarboxylase inhibitor, on plasma levels of aromatic-L-amino acid decarboxylase (ALAAD). After single-dose administration of L-dopa plus benserazide (Madopar) in healthy subjects and in chronically treated patients with parkinsonism, plasma ALAAD followed for 2 to 3 hours fell, but returned to predosing levels within 90 minutes. Four groups of patients with idiopathic parkinsonism were studied during chronic treatment: Group I, no L-dopa treatment (n = 31); Group II, L-dopa alone (n = 15); Group III, L-dopa plus benserazide (n = 28); and Group IV, L-dopa plus carbidopa (Sinemet, n = 30). Plasma ALAAD 2 hours after dosing was normal in Groups I and II. ALAAD was increased threefold in Groups III and IV, suggesting induction of ALAAD by the coadministration of a peripheral decarboxylase inhibitor. In a study of 3 patients in whom L-dopa/benserazide was started, plasma ALAAD rose gradually over 3 to 4 weeks. Further detailed pharmacokinetic studies of L-dopa, dopamine, and ALAAD in plasma and cerebrospinal fluid are required to determine if the apparent ALAAD induction by a peripheral decarboxylase inhibitor may be related to the loss of clinical efficacy of combination therapy in some patients and how it is related to end-of-dose deterioration and on-off phenomena.

  14. Epigenetic suppression of the antitumor cytotoxicity of NK cells by histone deacetylase inhibitor valproic acid

    PubMed Central

    Shi, Xiumin; Li, Min; Cui, Meizi; Niu, Chao; Xu, Jianting; Zhou, Lei; Li, Wei; Gao, Yushun; Kong, Weisheng; Cui, Jiuwei; Hu, Jifan; Jin, Haofan

    2016-01-01

    Natural killer (NK) cells play an essential role in the fight against tumor development. The therapeutic use of autologous NK cells has been exploited to treat human malignancies, yet only limited antitumor activity is observed in cancer patients. In this study, we sought to augment the antitumor activity of NK cells using epigenetic approaches. Four small molecules that have been known to promote epigenetic reprogramming were tested for their ability to enhance the activity of NK cells. Using a tumor cell lysis assay, we found that the DNA demethylating agent 5-azacytidine and vitamin C did not significantly affect the tumor killing ability of NK cells. The thyroid hormone triiodothyronine (T3) slightly increased the activity of NK cells. The histone deacetylase inhibitor valproic acid (VPA), however, inhibited NK cell lytic activity against leukemic cells in a dose-dependent manner. Pretreatment using VPA reduced IFNγ secretion, impaired CD107a degranulation, and induced apoptosis by activating the PD-1/PD-L1 pathway. VPA downregulated the expression of the activating receptor NKG2D (natural-killer group 2, member D) by inducing histone K9 hypermethylation and DNA methylation in the gene promoter. Histone deacetylase inhibitors have been developed as anticancer agents for use as monotherapies or in combination with other anticancer therapies. Our data suggest that the activity of histone deacetylase inhibitors on NK cell activity should be considered in drug development. PMID:27152238

  15. [Application of aspartic acid as a non-specific binding inhibitor in the enrichment of phosphopeptides with titanium dioxide].

    PubMed

    Chi, Ming; Bi, Wei; Lu, Zhuang; Song, Lina; Jia, Wei; Zhang, Yangjun; Qian, Xiaohong; Cai, Yun

    2010-02-01

    Titanium dioxide (TiO2) is one of metal oxides widely used for phosphopeptide enrichment in phosphoproteomic research nowadays. However it can bind to some non-phosphorylated peptides containing one or more aspartic acid residues and/or glutamic acid residues. These non-phosphorylated peptides can be eluted along with phosphorylated peptides and cause the reduction of the selectivity. Conventional inhibitors for the non-specific binding of non-phosphorylated peptides can often contaminate the ion source of mass spectrometry and therefore their applications are limited in liquid chromatography-mass spectrometry (LC-MS). In this study, aspartic acid was reported as a novel non-specific binding inhibitor for phosphopeptide enrichment by titanium dioxide. Firstly, the tryptic peptide mixtures of 3 and 9 standard proteins were used for the comparison of the enrichment efficiency of titanium dioxide. The effects with the presence of aspartic acid, glutamic acid and no-inhibitor in the enrichment systems were compared separately. The results showed that aspartic acid can greatly improve the selectivity of titanium dioxide for phosphopeptide enrichment. Then, aspartic acid was used for the enrichment of tryptic peptide mixture of C57BL/6J mouse liver lysate and good results were also obtained which demonstrated that aspartic acid was a promising non-specific binding inhibitor for complex biological samples. Besides, no contamination in the ion source occurred during the mass spectrometric analysis.

  16. Isolated etioplasts as test system for inhibitors of fatty acid biosynthesis

    SciTech Connect

    Lichtenthaler, H.K.; Kobek, K. )

    1989-04-01

    Isolated intact chloroplasts of mono- and dicotyledonous plants possess the capacity for de novo fatty acid biosynthesis, starting from {sup 14}C-acetate. These can be taken as test system for herbicides affecting fatty acid biosynthesis as shown earlier in our laboratory. The incorporation rates of acetate into the total fatty acids depend on the photosynthetic cofactors ATP and NADPH and amount in the light to 33 kBq (oat) and 39 kBq (pea) per mg chlorophyll x h, whereas in the dark only ca. 10% of these rates are obtained. In order to establish a test system, which is fully independent of light, we isolated and characterized etioplast fractions from oat and pea seedlings with a very high capacity of de novo fatty acid biosynthesis (500 and 400 kBq per mg carotenoids in a 20 min period). This activity was blocked by herbicides such as cycloxydim, sethoxydim and diclofop in a dose-dependent manner. This new test system has the great advantage that one can verify whether inhibitors of photosynthesis affect fatty acid biosynthesis.

  17. Rhodanine-3-acetic acid derivatives as inhibitors of fungal protein mannosyl transferase 1 (PMT1).

    PubMed

    Orchard, Michael G; Neuss, Judi C; Galley, Carl M S; Carr, Andrew; Porter, David W; Smith, Phillip; Scopes, David I C; Haydon, David; Vousden, Katherine; Stubberfield, Colin R; Young, Kate; Page, Martin

    2004-08-01

    The first inhibitors of fungal protein: mannosyl transferase 1 (PMT1) are described. They are based upon rhodanine-3-acetic acid and several compounds have been identified, for example, 5-[[3-(1-phenylethoxy)-4-(2-phenylethoxy)phenyl]methylene]-4-oxo-2-thioxo-3-thiazolidineacetic acid (5a), which inhibit Candida albicans PMT1 with IC(50)s in the range 0.2-0.5 microM. Members of the series are effective in inducing changes in morphology of C. albicans in vitro that have previously been associated with loss of the transferase activity. These compounds could serve as useful tools for studying the effects of protein O-mannosylation and its relevance in the search for novel antifungal agents. PMID:15225710

  18. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation

    PubMed Central

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-01-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media. PMID:23938301

  19. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation

    NASA Astrophysics Data System (ADS)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-08-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media.

  20. Adaptive laboratory evolution of ethanologenic Zymomonas mobilis strain tolerant to furfural and acetic acid inhibitors.

    PubMed

    Shui, Zong-Xia; Qin, Han; Wu, Bo; Ruan, Zhi-yong; Wang, Lu-shang; Tan, Fu-Rong; Wang, Jing-Li; Tang, Xiao-Yu; Dai, Li-Chun; Hu, Guo-Quan; He, Ming-Xiong

    2015-07-01

    Furfural and acetic acid from lignocellulosic hydrolysates are the prevalent inhibitors to Zymomonas mobilis during cellulosic ethanol production. Developing a strain tolerant to furfural or acetic acid inhibitors is difficul by using rational engineering strategies due to poor understanding of their underlying molecular mechanisms. In this study, strategy of adaptive laboratory evolution (ALE) was used for development of a furfural and acetic acid-tolerant strain. After three round evolution, four evolved mutants (ZMA7-2, ZMA7-3, ZMF3-2, and ZMF3-3) that showed higher growth capacity were successfully obtained via ALE method. Based on the results of profiling of cell growth, glucose utilization, ethanol yield, and activity of key enzymes, two desired strains, ZMA7-2 and ZMF3-3, were achieved, which showed higher tolerance under 7 g/l acetic acid and 3 g/l furfural stress condition. Especially, it is the first report of Z. mobilis strain that could tolerate higher furfural. The best strain, Z. mobilis ZMF3-3, has showed 94.84% theoretical ethanol yield under 3-g/l furfural stress condition, and the theoretical ethanol yield of ZM4 is only 9.89%. Our study also demonstrated that ALE method might also be used as a powerful metabolic engineering tool for metabolic engineering in Z. mobilis. Furthermore, the two best strains could be used as novel host for further metabolic engineering in cellulosic ethanol or future biorefinery. Importantly, the two strains may also be used as novel-tolerant model organisms for the genetic mechanism on the "omics" level, which will provide some useful information for inverse metabolic engineering.

  1. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation

    PubMed Central

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Xu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-01-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS-2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro-inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of RSV infection

  2. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation.

    PubMed

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Χu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-09-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS‑2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro‑inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of

  3. Identification of KMU-3, a novel derivative of gallic acid, as an inhibitor of adipogenesis.

    PubMed

    Park, Yu-Kyoung; Lee, Jinho; Hong, Victor Sukbong; Choi, Jong-Soon; Lee, Tae-Yoon; Jang, Byeong-Churl

    2014-01-01

    Differentiation of preadipocyte, also called adipogenesis, leads to the phenotype of mature adipocyte. Excessive adipogenesis, however, is largely linked to the development of obesity. Herein we investigated a library of 53 novel chemicals, generated from a number of polyphenolic natural compounds, on adipogenesis. Strikingly, among the chemicals tested, KMU-3, a derivative of gallic acid, strongly suppressed lipid accumulation during the differentiation of 3T3-L1 preadipocytes into adipocytes. On mechanistic levels, KMU-3 inhibited expressions of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and fatty acid synthase (FAS) during adipocyte differentiation. Moreover, KMU-3 reduced expressions of adipokines, including retinol binding protein-4 (RBP-4), leptin, and regulated on activation, normal T cell expressed and secreted (RANTES) during adipocyte differentiation. Of further note, KMU-3 rapidly blocked the phosphorylation of signal transducer and activator of transcription-3 (STAT-3) during the early stage of adipogenesis. Importantly, pharmacological inhibition studies revealed that AG490, a JAK-2/STAT-3 inhibitor suppressed adipogenesis and STAT-3 phosphorylation, implying that early blockage of STAT-3 activity is crucial for the KMU-3-mediated anti-adipogenesis. These findings demonstrate firstly that KMU-3 inhibits adipogenesis by down-regulating STAT-3, PPAR-γ, C/EBP-α, and FAS. This work shows that KMU-3 is an inhibitor of adipogenesis and thus may have therapeutic potential against obesity.

  4. The myeloperoxidase product hypochlorous acid generates irreversible high-density lipoprotein receptor inhibitors

    PubMed Central

    Binder, Veronika; Ljubojevic, Senka; Haybaeck, Johannes; Holzer, Michael; El-Gamal, Dalia; Schicho, Rudolf; Pieske, Burkert; Heinemann, Akos; Marsche, Gunther

    2014-01-01

    Objective Elevated levels of advanced oxidation protein products (AOPPs) have been described in several chronic inflammatory diseases, like chronic renal insufficiency, rheumatoid arthritis and atherosclerosis. Recent findings revealed that AOPPs are inhibitors of the major high-density lipoprotein (HDL) receptor, scavenger receptor class B, type 1 (SR-BI). Here we investigated what oxidation induced structural alterations convert plasma albumin into an HDL-receptor inhibitor. Approach and Results Exposure of albumin to the physiological oxidant, hypochlorous acid, generated high affinity SR-BI ligands. Protection of albumin lysine-residues prior exposure to hypochlorous acid as well as regeneration of N-chloramines after oxidation of albumin completely prevented binding of oxidized albumin to SR-BI, indicating that modification of albumin lysine-residues is required to generate SR-BI ligands. Of particular interest, N-chloramines within oxidized albumin promoted irreversible binding to SR-BI, resulting in permanent receptor blockade. We observed that the SR-BI inhibitory activity of albumin isolated from chronic kidney disease patients correlated with the content of the myeloperoxidase-specific oxidation product 3-chlorotyrosine and was associated with alterations in the composition of HDL. Conclusion Given that several potential atheroprotective activities of HDL are mediated by SR-BI, the present results raise the possibility that oxidized plasma albumin, through permanent SR-BI blockade, contributes to the pathophysiology of cardiovascular disease. PMID:23493288

  5. Click Chemistry in Lead Optimization of Boronic Acids as β-Lactamase Inhibitors.

    PubMed

    Caselli, Emilia; Romagnoli, Chiara; Vahabi, Roza; Taracila, Magdalena A; Bonomo, Robert A; Prati, Fabio

    2015-07-23

    Boronic acid transition-state inhibitors (BATSIs) represent one of the most promising classes of β-lactamase inhibitors. Here we describe a new class of BATSIs, namely, 1-amido-2-triazolylethaneboronic acids, which were synthesized by combining the asymmetric homologation of boronates with copper-catalyzed azide-alkyne cycloaddition for the stereoselective insertion of the amido group and the regioselective formation of the 1,4-disubstituted triazole, respectively. This synthetic pathway, which avoids intermediate purifications, proved to be flexible and efficient, affording in good yields a panel of 14 BATSIs bearing three different R1 amide side chains (acetamido, benzylamido, and 2-thienylacetamido) and several R substituents on the triazole. This small library was tested against two clinically relevant class C β-lactamases from Enterobacter spp. and Pseudomonas aeruginosa. The K(i) value of the best compound (13a) was as low as 4 nM with significant reduction of bacterial resistance to the combination of cefotaxime/13a. PMID:26102369

  6. Pharmacodynamic effects of antibiotics and acid pump inhibitors on Helicobacter pylori.

    PubMed Central

    Sörberg, M; Hanberger, H; Nilsson, M; Nilsson, L E

    1997-01-01

    Pharmacodynamic studies of Helicobacter pylori exposed to amoxicillin, clarithromycin, metronidazole, omeprazole, and lansoprazole were performed with microscopy, viable count determination, and bioluminescence assay of intracellular ATP. The pharmacodynamic parameters determined were change in morphology, change in cell density, postantibiotic effect (PAE), and control-related effective regrowth time (CERT). The PAE is delayed regrowth after brief exposure to antibiotics or acid pump inhibitors. CERT was defined as the time required for the bacteria to resume logarithmic growth and return to the pre-exposure inoculum in the test culture minus the corresponding time for the control culture. CERT measures the combined effect of initial killing and PAE. There was a good concordance between the bioluminescence assay and viable counts for determining CERT, which makes this parameter useful for pharmacodynamic studies of the effects of antibiotics and acid pump inhibitors on H. pylori. Amoxicillin and metronidazole produced a strong, concentration-dependent initial decrease in CFU per milliliter, but there was a less prominent initial change in intracellular ATP in these cultures. Amoxicillin caused a long PAE when assayed by the bioluminescence assay but no PAE or a negative PAE when assayed by viable count determination. However, amoxicillin showed similar long CERTs with both methods. The pharmacodynamic effects of amoxicillin were concentration dependent up to a maximum response, indicating that concentrations above this level do not increase the antibiotic effect. The PAEs and CERTs of clarithromycin and metronidazole were concentration dependent with no maximum response. With omeprazole and lanzoprazole, there was no PAE or CERT. PMID:9333051

  7. Resveratrol and P-glycoprotein Inhibitors Enhance the Anti-skin Cancer Effects of Ursolic Acid

    PubMed Central

    Junco, Jacob J.; Mancha, Anna; Malik, Gunjan; Wei, Sung-Jen; Kim, Dae Joon; Liang, Huiyun; Slaga, Thomas J.

    2013-01-01

    Ursolic acid (UA), present in apples, rosemary, and other sources, is known to inhibit tumor formation and tumor cell viability in multiple systems, including skin. However, various cancers are resistant to UA treatment. Herein, skin carcinoma cells (Ca3/7) as compared to skin papilloma cells (MT1/2) displayed more resistance to UA-induced cytotoxicity. Interestingly, Ca3/7 cells had elevated levels of P-glycoprotein (P-gp), an ATP-dependent efflux pump that mediates resistance to chemotherapy in pre-clinical and clinical settings, and not only accumulated less but also more rapidly expelled the P-gp substrate Rhodamine 123 (Rh123) indicating UA is transported by P-gp. To determine if P-gp inhibition can enhance UA-mediated cytotoxicity, cells were challenged with P-gp inhibitors verapamil (VRP) or cyclosporin A (CsA). Alternatively, cells were pre-treated with the natural compound resveratrol (RES), a known chemotherapy sensitizer. VRP and RES enhanced the effects of UA in both cell lines, while CsA only did so in Ca3/7 cells. Similarly, VRP inhibited Rh123 efflux in both lines, while CsA only inhibited Rh123 efflux in Ca3/7 cells. RES did not inhibit Rh123 efflux in either line, indicating the synergistic effects of RES and UA are not manifest by inhibition of P-gp-mediated efflux of UA. These results indicate that the anti-skin cancer effects of UA are enhanced with P-gp inhibitors. In addition, RES and UA interact synergistically, but not through inhibition of P-gp. Implications Resveratrol and/or p-glycoprotein inhibitors in combination with ursolic acid are an effective anti-skin cancer regimen. PMID:24072817

  8. Use of class I histone deacetylase inhibitor romidepsin in combination regimens.

    PubMed

    Petrich, Adam; Nabhan, Chadi

    2016-08-01

    Histone deacetylase (HDAC) inhibitors are epigenetic-modifying agents that have shown promise as anticancer therapies. Several HDAC inhibitors have been approved by the US Food and Drug Administration (FDA) as single-agent therapies to treat T-cell lymphoma. The synergistic combination of HDAC inhibitors with other anticancer agents has the potential to constitute treatment regimens with enhanced efficacy. Romidepsin is a structurally unique, potent, bicyclic class 1 selective HDAC inhibitor approved by the FDA for the treatment of patients with peripheral T-cell lymphoma who have had at least 1 prior therapy and patients with cutaneous T-cell lymphoma who have had at least 1 prior systemic therapy. Here, we review data that support the use of romidepsin in combination with other anticancer agents for the treatment of various malignancies. Promising results have emerged from early clinical studies, supporting the potential for romidepsin combination regimens to constitute safe and effective treatments for cancer.

  9. Use of class I histone deacetylase inhibitor romidepsin in combination regimens

    PubMed Central

    Petrich, Adam; Nabhan, Chadi

    2016-01-01

    Abstract Histone deacetylase (HDAC) inhibitors are epigenetic-modifying agents that have shown promise as anticancer therapies. Several HDAC inhibitors have been approved by the US Food and Drug Administration (FDA) as single-agent therapies to treat T-cell lymphoma. The synergistic combination of HDAC inhibitors with other anticancer agents has the potential to constitute treatment regimens with enhanced efficacy. Romidepsin is a structurally unique, potent, bicyclic class 1 selective HDAC inhibitor approved by the FDA for the treatment of patients with peripheral T-cell lymphoma who have had at least 1 prior therapy and patients with cutaneous T-cell lymphoma who have had at least 1 prior systemic therapy. Here, we review data that support the use of romidepsin in combination with other anticancer agents for the treatment of various malignancies. Promising results have emerged from early clinical studies, supporting the potential for romidepsin combination regimens to constitute safe and effective treatments for cancer. PMID:27118119

  10. Dianils: New and effective corrosion inhibitors for oil-well steel (N-80) and mild steel in boiling hydrochloric acid

    SciTech Connect

    Quraishi, M.A.; Jamal, D.

    2000-02-01

    Selected condensation products of aromatic aldehydes and p-phenylenediamine have been synthesized and evaluated as corrosion inhibitors for mild steel (MS) and oil-well steel (N-80) in 15% hydrochloric acid (HCl) at 105 C {+-} 2 C by the weight loss method. All the condensation products showed excellent performance. 2,4-dicinnamyledene aminophenylene (DCAP) was found to be the best corrosion inhibitor. It exhibited 99.75% inhibition efficiency (IE) for MS and 99.12% for N-80 steel at 5,000 ppm of inhibitor concentration. The potentiodynamic polarization studies carried out at room temperature on MS in 15% HCl containing 500 ppm of condensation products showed that all the investigated compounds were mixed type inhibitors, whereas 500 ppm DCAP on N-80 steel behaved predominantly as anodic inhibitors. The adsorption of all the condensation products was found to obey Temkin's adsorption isotherm.

  11. A microenvironment-mediated c-Myc/miR-548m/HDAC6 amplification loop in non-Hodgkin B cell lymphomas

    PubMed Central

    Lwin, Tint; Zhao, Xiaohong; Cheng, Fengdong; Zhang, Xinwei; Huang, Andy; Shah, Bijal; Zhang, Yizhuo; Moscinski, Lynn C.; Choi, Yong Sung; Kozikowski, Alan P.; Bradner, James E.; Dalton, William S.; Sotomayor, Eduardo; Tao, Jianguo

    2013-01-01

    A dynamic interaction occurs between the lymphoma cell and its microenvironment, with each profoundly influencing the behavior of the other. Here, using a clonogenic coculture growth system and a xenograft mouse model, we demonstrated that adhesion of mantle cell lymphoma (MCL) and other non-Hodgkin lymphoma cells to lymphoma stromal cells confers drug resistance, clonogenicity, and induction of histone deacetylase 6 (HDAC6). Furthermore, stroma triggered a c-Myc/miR-548m feed-forward loop, linking sustained c-Myc activation, miR-548m downregulation, and subsequent HDAC6 upregulation and stroma-mediated cell survival and lymphoma progression in lymphoma cell lines, primary MCL and other B cell lymphoma cell lines. Treatment with an HDAC6-selective inhibitor alone or in synergy with a c-Myc inhibitor enhanced cell death, abolished cell adhesion–mediated drug resistance, and suppressed clonogenicity and lymphoma growth ex vivo and in vivo. Together, these data suggest that the lymphoma-stroma interaction in the lymphoma microenvironment directly impacts the biology of lymphoma through genetic and epigenetic regulation, with HDAC6 and c-Myc as potential therapeutic targets. PMID:24216476

  12. PET imaging demonstrates histone deacetylase target engagement and clarifies brain penetrance of known and novel small molecule inhibitors in rat.

    PubMed

    Schroeder, F A; Wang, C; Van de Bittner, G C; Neelamegam, R; Takakura, W R; Karunakaran, A; Wey, H Y; Reis, S A; Gale, J; Zhang, Y L; Holson, E B; Haggarty, S J; Hooker, J M

    2014-10-15

    Histone deacetylase (HDAC) enzymes have been demonstrated as critical components in maintaining chromatin homeostasis, CNS development, and normal brain function. Evidence in mouse models links HDAC expression to learning, memory, and mood-related behaviors; small molecule HDAC inhibitor tool compounds have been used to demonstrate the importance of specific HDAC subtypes in modulating CNS-disease-related behaviors in rodents. So far, no direct evidence exists to understand the quantitative changes in HDAC target engagement that are necessary to alter biochemistry and behavior in a living animal. Understanding the relationship between target engagement and in vivo effect is essential in refining new ways to alleviate disease. We describe here, using positron emission tomography (PET) imaging of rat brain, the in vivo target engagement of a subset of class I/IIb HDAC enzymes implicated in CNS-disease (HDAC subtypes 1, 2, 3, and 6). We found marked differences in the brain penetrance of tool compounds from the hydroxamate and benzamide HDAC inhibitor classes and resolved a novel, highly brain penetrant benzamide, CN147, chronic treatment with which resulted in an antidepressant-like effect in a rat behavioral test. Our work highlights a new translational path for understanding the molecular and behavioral consequences of HDAC target engagement. PMID:25188794

  13. Analysis of the genomic response of human prostate cancer cells to histone deacetylase inhibitors

    PubMed Central

    Kortenhorst, Madeleine SQ; Wissing, Michel D; Rodriguez, Ronald; Kachhap, Sushant K; Jans, Judith JM; Van der Groep, Petra; Verheul, Henk MW; Gupta, Anuj; Aiyetan, Paul O; van der Wall, Elsken; Carducci, Michael A; Van Diest, Paul J; Marchionni, Luigi

    2013-01-01

    Histone deacetylases (HDACs) have emerged as important targets for cancer treatment. HDAC-inhibitors (HDACis) are well tolerated in patients and have been approved for the treatment of patients with cutaneous T-cell lymphoma (CTCL). To improve the clinical benefit of HDACis in solid tumors, combination strategies with HDACis could be employed. In this study, we applied Analysis of Functional Annotation (AFA) to provide a comprehensive list of genes and pathways affected upon HDACi-treatment in prostate cancer cells. This approach provides an unbiased and objective approach to high throughput data mining. By performing AFA on gene expression data from prostate cancer cell lines DU-145 (an HDACi-sensitive cell line) and PC3 (a relatively HDACi-resistant cell line) treated with HDACis valproic acid or vorinostat, we identified biological processes that are affected by HDACis and are therefore potential treatment targets for combination therapy. Our analysis revealed that HDAC-inhibition resulted among others in upregulation of major histocompatibility complex (MHC) genes and deregulation of the mitotic spindle checkpoint by downregulation of genes involved in mitosis. These findings were confirmed by AFA on publicly available data sets from HDACi-treated prostate cancer cells. In total, we analyzed 375 microarrays with HDACi treated and non-treated (control) prostate cancer cells. All results from this extensive analysis are provided as an online research source (available at the journal’s website and at http://luigimarchionni.org/HDACIs.html). By publishing this data, we aim to enhance our understanding of the cellular changes after HDAC-inhibition, and to identify novel potential combination strategies with HDACis for the treatment of prostate cancer patients. PMID:23880963

  14. HDAC4 is required for inflammation-associated thermal hypersensitivity

    PubMed Central

    Crow, Megan; Khovanov, Nikita; Kelleher, Jayne H.; Sharma, Simone; Grant, Andrew D.; Bogdanov, Yury; Wood, John N.; McMahon, Stephen B.; Denk, Franziska

    2015-01-01

    Transcriptional alterations are characteristic of persistent pain states, but the key regulators remain elusive. HDAC4 is a transcriptional corepressor that has been linked to synaptic plasticity and neuronal excitability, mechanisms that may be involved in peripheral and central sensitization. Using a conditional knockout (cKO) strategy in mice, we sought to determine whether the loss of HDAC4 would have implications for sensory neuron transcription and nociception. HDAC4 was found to be largely unnecessary for transcriptional regulation of naïve sensory neurons but was essential for appropriate transcriptional responses after injury, with Calca and Trpv1 expression consistently down-regulated in HDAC4 cKO compared to levels in the littermate controls (0.2–0.44-fold change, n = 4 in 2 separate experiments). This down-regulation corresponded to reduced sensitivity to 100 nM capsaicin in vitro (IC50 = 230 ± 20 nM, 76 ± 4.4% wild-type capsaicin responders vs. 56.9 ± 4.7% HDAC4 cKO responders) and to reduced thermal hypersensitivity in the complete Freund’s adjuvant (CFA) model of inflammatory pain (1.3–1.4-fold improvement over wild-type controls; n = 5–12, in 2 separate experiments). These data indicate that HDAC4 is a novel inflammatory pain mediator and may be a good therapeutic target, capable of orchestrating the regulation of multiple downstream effectors.—Crow, M., Khovanov, N., Kelleher, J. H., Sharma, S., Grant, A. D., Bogdanov, Y., Wood, J. N., McMahon, S. B., Denk, F. HDAC4 is required for inflammation-associated thermal hypersensitivity. PMID:25903105

  15. Theoretical study of inhibition efficiencies of some amino acids on corrosion of carbon steel in acidic media: green corrosion inhibitors.

    PubMed

    Dehdab, Maryam; Shahraki, Mehdi; Habibi-Khorassani, Sayyed Mostafa

    2016-01-01

    Inhibition efficiencies of three amino acids [tryptophan (B), tyrosine (c), and serine (A)] have been studied as green corrosion inhibitors on corrosion of carbon steel using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EH OMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability ([Formula: see text]), total negative charges on atoms (TNC), molecular volume (MV) and total energy (TE) have been calculated at the B3LYP level of theory with 6-311++G** basis set. Consistent with experimental data, theoretical results showed that the order of inhibition efficiency is tryptophan (B) > tyrosine (C) > serine (A). In order to determine the possible sites of nucleophilic and electrophilic attacks, local reactivity has been evaluated through Fukui indices.

  16. Discovery of FDA-approved drugs as inhibitors of fatty acid binding protein 4 using molecular docking screening.

    PubMed

    Wang, Yan; Law, Wai-Kit; Hu, Jian-Shu; Lin, Huang-Quan; Ip, Tsz-Ming; Wan, David Chi-Cheong

    2014-11-24

    We first identified fluorescein, ketazolam, antrafenine, darifenacin, fosaprepitant, paliperidone, risperidone, pimozide, trovafloxacin, and levofloxacin as inhibitors of fatty acid binding protein 4 using molecular docking screening from FDA-approved drugs. Subsequently, the biochemical characterizations showed that levofloxacin directly inhibited FABP4 activity in both the in vitro ligand displacement assay and cell-based function assay. Furthermore, levofloxacin did not induce adipogenesis in adipocytes, which is the major adverse effect of FABP4 inhibitors.

  17. Mass Spectrometry-Based Systems Approach for Identification of Inhibitors of Plasmodium falciparum Fatty Acid Synthase▿

    PubMed Central

    Sharma, Shilpi; Sharma, Shailendra Kumar; Modak, Rahul; Karmodiya, Krishanpal; Surolia, Namita; Surolia, Avadhesha

    2007-01-01

    The emergence of strains of Plasmodium falciparum resistant to the commonly used antimalarials warrants the development of new antimalarial agents. The discovery of type II fatty acid synthase (FAS) in Plasmodium distinct from the FAS in its human host (type I FAS) opened up new avenues for the development of novel antimalarials. The process of fatty acid synthesis takes place by iterative elongation of butyryl-acyl carrier protein (butyryl-ACP) by two carbon units, with the successive action of four enzymes constituting the elongation module of FAS until the desired acyl length is obtained. The study of the fatty acid synthesis machinery of the parasite inside the red blood cell culture has always been a challenging task. Here, we report the in vitro reconstitution of the elongation module of the FAS of malaria parasite involving all four enzymes, FabB/F (β-ketoacyl-ACP synthase), FabG (β-ketoacyl-ACP reductase), FabZ (β-ketoacyl-ACP dehydratase), and FabI (enoyl-ACP reductase), and its analysis by matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS). That this in vitro systems approach completely mimics the in vivo machinery is confirmed by the distribution of acyl products. Using known inhibitors of the enzymes of the elongation module, cerulenin, triclosan, NAS-21/91, and (−)-catechin gallate, we demonstrate that accumulation of intermediates resulting from the inhibition of any of the enzymes can be unambiguously followed by MALDI-TOF MS. Thus, this work not only offers a powerful tool for easier and faster throughput screening of inhibitors but also allows for the study of the biochemical properties of the FAS pathway of the malaria parasite. PMID:17485508

  18. The p65 (RelA) Subunit of NF-κB Interacts with the Histone Deacetylase (HDAC) Corepressors HDAC1 and HDAC2 To Negatively Regulate Gene Expression

    PubMed Central

    Ashburner, Brian P.; Westerheide, Sandy D.; Baldwin, Albert S.

    2001-01-01

    Regulation of NF-κB transactivation function is controlled at several levels, including interactions with coactivator proteins. Here we show that the transactivation function of NF-κB is also regulated through interaction of the p65 (RelA) subunit with histone deacetylase (HDAC) corepressor proteins. Our results show that inhibition of HDAC activity with trichostatin A (TSA) results in an increase in both basal and induced expression of an integrated NF-κB-dependent reporter gene. Chromatin immunoprecipitation (ChIP) assays show that TSA treatment causes hyperacetylation of the wild-type integrated NF-κB-dependent reporter but not of a mutant version in which the NF-κB binding sites were mutated. Expression of HDAC1 and HDAC2 repressed tumor necrosis factor (TNF)-induced NF-κB-dependent gene expression. Consistent with this, we show that HDAC1 and HDAC2 target NF-κB through a direct association of HDAC1 with the Rel homology domain of p65. HDAC2 does not interact with NF-κB directly but can regulate NF-κB activity through its association with HDAC1. Finally, we show that inhibition of HDAC activity with TSA causes an increase in both basal and TNF-induced expression of the NF-κB-regulated interleukin-8 (IL-8) gene. Similar to the wild-type integrated NF-κB-dependent reporter, ChIP assays showed that TSA treatment resulted in hyperacetylation of the IL-8 promoter. These data indicate that the transactivation function of NF-κB is regulated in part through its association with HDAC corepressor proteins. Moreover, it suggests that the association of NF-κB with the HDAC1 and HDAC2 corepressor proteins functions to repress expression of NF-κB-regulated genes as well as to control the induced level of expression of these genes. PMID:11564889

  19. Circadian Epigenomic Remodeling and Hepatic Lipogenesis: Lessons from HDAC3

    PubMed Central

    Sun, Zheng; Feng, Dan; Everett, Logan J.; Bugge, Anne; Lazar, Mitchell A.

    2013-01-01

    Circadian rhythms have evolved to anticipate metabolic needs across the 24-hour light/dark cycle. This is accomplished by circadian expression of metabolic genes orchestrated by transcription factors through chromatin remodeling and histone modifications. Our recent genome-wide study on histone deacetylase 3 (HDAC3) in mouse liver provides novel insights into the molecular link between circadian rhythm and hepatic de novo lipogenesis. We found that liver-specific knockout of HDAC3 in adult mouse display severe hepatic steatosis associated with enhanced de novo lipogenesis and increased expression of lipogenic genes. Genome-wide analysis (ChIP-seq) revealed a pronounced circadian pattern of HDAC3 occupancy on genes involved in lipid metabolism, which is inversely related to histone acetylation and RNA polymerase II recruitment at these sites. The cistromes of HDAC3 and its binding partner, nuclear receptor co-repressor (NCoR), significantly overlap with that of Rev-erbα, a nuclear receptor directly involved in the core circadian machinery. Knockout of Rev-erbα in mouse also leads to hepatic steatosis and enhanced de novo lipogenesis. Collectively, these data suggest that the circadian epigenomic remodeling controlled by HDAC3, and largely directed by Rev-erbα, is essential for homeostasis of the lipogenic process in liver. PMID:21900149

  20. Concentrated sulfite-yeast fermenting mixture as a corrosion inhibitor of copper in mixtures of sulfuric and nitric acid

    SciTech Connect

    Agaev, N.M.; Smorodin, A.E.; Rzaev, E.R.; Tyr, S.G.; Shlimak, Ya.B.; Geidarova, G.D.; Eremeeva, R.A.; Nasirov, G.N.

    1987-03-01

    At the Baku factory of residential air conditioning systems both preliminary and final pickling of copper tubing is carried out in a solution of sulfuric and nitric acids. The authors of this study, in seeking an inhibitor to control this process, evaluate the protective properties of an inhibitor based on a concentrated sulfite-yeast fermenting mixture that is generated as a common waste product by the cellulose-pulp industry. It consists of calcium, sodium, and ammonium salts of lignin sulfonic acids. Tests revealed not only its inhibiting effectiveness but also its capacity to lower toxic gas levels of nitrogen oxides in the plant environment.

  1. Structure activity relationship of phenolic acid inhibitors of α-synuclein fibril formation and toxicity

    PubMed Central

    Ardah, Mustafa T.; Paleologou, Katerina E.; Lv, Guohua; Abul Khair, Salema B.; Kazim, Abdulla S.; Minhas, Saeed T.; Al-Tel, Taleb H.; Al-Hayani, Abdulmonem A.; Haque, Mohammed E.; Eliezer, David; El-Agnaf, Omar M. A.

    2014-01-01

    The aggregation of α-synuclein (α-syn) is considered the key pathogenic event in many neurological disorders such as Parkinson's disease (PD), dementia with Lewy bodies and multiple system atrophy, giving rise to a whole category of neurodegenerative diseases known as synucleinopathies. Although the molecular basis of α-syn toxicity has not been precisely elucidated, a great deal of effort has been put into identifying compounds that could inhibit or even reverse the aggregation process. Previous reports indicated that many phenolic compounds are potent inhibitors of α-syn aggregation. The aim of the present study was to assess the anti-aggregating effect of gallic acid (GA) (3,4,5-trihydroxybenzoic acid), a benzoic acid derivative that belongs to a group of phenolic compounds known as phenolic acids. By employing an array of biophysical and biochemical techniques and a cell-viability assay, GA was shown not only to inhibit α-syn fibrillation and toxicity but also to disaggregate preformed α-syn amyloid fibrils. Interestingly, GA was found to bind to soluble, non-toxic oligomers with no β-sheet content, and to stabilize their structure. The binding of GA to the oligomers may represent a potential mechanism of action. Additionally, by using structure activity relationship data obtained from fourteen structurally similar benzoic acid derivatives, it was determined that the inhibition of α-syn fibrillation by GA is related to the number of hydroxyl moieties and their position on the phenyl ring. GA may represent the starting point for designing new molecules that could be used for the treatment of PD and related disorders. PMID:25140150

  2. Synthesis and biological evaluation of enantiomerically pure glyceric acid derivatives as LpxC inhibitors.

    PubMed

    Tangherlini, Giovanni; Torregrossa, Tullio; Agoglitta, Oriana; Köhler, Jens; Melesina, Jelena; Sippl, Wolfgang; Holl, Ralph

    2016-03-01

    Inhibitors of the UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase (LpxC) represent a promising class of novel antibiotics, selectively combating Gram-negative bacteria. In order to elucidate the impact of the hydroxymethyl groups of diol (S,S)-4 on the inhibitory activity against LpxC, glyceric acid ethers (R)-7a, (S)-7a, (R)-7b, and (S)-7b, lacking the hydroxymethyl group in benzylic position, were synthesized. The compounds were obtained in enantiomerically pure form by a chiral pool synthesis and a lipase-catalyzed enantioselective desymmetrization, respectively. The enantiomeric hydroxamic acids (R)-7b (Ki=230nM) and (S)-7b (Ki=390nM) show promising enzyme inhibition. However, their inhibitory activities do not substantially differ from each other leading to a low eudismic ratio. Generally, the synthesized glyceric acid derivatives 7 show antibacterial activities against two Escherichia coli strains exceeding the ones of their respective regioisomes 6.

  3. USP4 inhibits p53 and NF-κB through deubiquitinating and stabilizing HDAC2

    PubMed Central

    Li, Z; Hao, Q; Luo, J; Xiong, J; Zhang, S; Wang, T; Bai, L; Wang, W; Chen, M; Wang, W; Gu, L; Lv, K; Chen, J

    2016-01-01

    Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. As HDACs are promising targets of cancer therapy, it is important to understand the mechanisms of HDAC regulation. In this study, we show that ubiquitin-specific peptidase 4 (USP4) interacts directly with and deubiquitinates HDAC2, leading to the stabilization of HDAC2. Accumulation of HDAC2 in USP4-overexpression cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation and apoptotic response upon DNA damage. Moreover, USP4 targets HDAC2 to downregulate tumor necrosis factor TNFα-induced nuclear factor (NF)-κB activation. Taken together, our study provides a novel insight into the ubiquitination and stability of HDAC2 and uncovers a previously unknown function of USP4 in cancers. PMID:26411366

  4. Structure-Based Identification of HDAC8 Non-histone Substrates.

    PubMed

    Alam, Nawsad; Zimmerman, Lior; Wolfson, Noah A; Joseph, Caleb G; Fierke, Carol A; Schueler-Furman, Ora

    2016-03-01

    HDAC8 is a member of the family of histone deacetylases (HDACs) that catalyze the deacetylation of acetyl lysine residues within histone and non-histone proteins. The recent identification of novel non-histone HDAC8 substrates such as SMC3, ERRα, and ARID1A indicates a complex functionality of this enzyme in cellular homeostasis. To discover additional HDAC8 substrates, we developed a comprehensive, structure-based approach based on Rosetta FlexPepBind, a protocol that evaluates peptide-binding ability to a receptor from structural models of this interaction. Here we adapt this protocol to identify HDAC8 substrates using peptide sequences extracted from proteins with known acetylated sites. The many new in vitro HDAC8 peptide substrates identified in this study suggest that numerous cellular proteins are HDAC8 substrates, thus expanding our view of the acetylome and its regulation by HDAC8. PMID:26933971

  5. HDAC Inhibition Blunts Ischemia/Reperfusion Injury by Inducing Cardiomyocyte Autophagy

    PubMed Central

    Xie, Min; Kong, Yongli; Tan, Wei; May, Herman; Battiprolu, Pavan K.; Pedrozo, Zully; Wang, Zhao; Morales, Cyndi; Luo, Xiang; Cho, Geoffrey; Jiang, Nan; Jessen, Michael E.; Warner, John J.; Lavandero, Sergio; Gillette, Thomas G.; Turer, Aslan T.; Hill, Joseph A.

    2014-01-01

    Background Reperfusion accounts for a substantial fraction of the myocardial injury occurring with ischemic heart disease. Yet, no standard therapies are available targeting reperfusion injury. Here, we tested the hypothesis that SAHA, a histone deacetylase (HDAC) inhibitor FDA-approved for cancer treatment, will blunt reperfusion injury. Methods and Results Twenty-one rabbits were randomized into 3 groups: a) vehicle control, b) SAHA pretreatment (one day prior and at surgery), and c) SAHA treatment at the time of reperfusion only. Each arm was subjected to ischemia/reperfusion surgery (I/R, 30min coronary ligation, 24h reperfusion). Additionally cultured neonatal and adult rat ventricular cardiomyocytes were subjected to simulated I/R (sI/R) to probe mechanism. SAHA reduced infarct (those reduction inhibitor, SAHA, infarct size in a large animal model, even when delivered in the clinically relevant context of reperfusion. The cardioprotective effects of SAHA during I/R occur, at least in part, through induction of autophagic flux. assayed in both rabbit myocardium and in mice harboring an RFP-GFP-LC3 transgene. In cultured myocytes subjected to sI/R, SAHA pretreatment reduced cell death by 40%. This eduction in cell death correlated with increased autophagic activity in SAHA-treated cells. RNAi-mediated knockdown of ATG7 and ATG5, essential autophagy proteins, abolished SAHA's cardioprotective effects. Conclusions The FDS-approved anti-cancer HDAC inhibitor, SAHA, reduces myocardial infarct size in a large animal model, even when delivered in the clinically relevant context of reperfusion. The cardioprotective effects of SAHA during I/R occur, at least in part, through induction of autophagic flux. PMID:24396039

  6. Study of Ellagic Acid as a Natural Elastase Inhibitor by Spectroscopic Methods

    NASA Astrophysics Data System (ADS)

    Xing, X.; Yang, X.; Cao, Yu.

    2016-03-01

    A new natural inhibitor, ellagic acid (EA), was developed, and its inhibition efficiency on elastase was studied by spectroscopic methods. The experimental results proved that EA is a potent elastase inhibitor with an IC50 value of 1.44 mg/mL by UV-vis spectroscopy, and the inhibition mechanism of elastase was confirmed by fluorescence quenching. The interacting between EA and elastase was mainly based on the static quenching owing to the complex formation when the concentration of EA was ≤40 μM. Fluorescence quenching mainly occurred via dynamic quenching with increasing EA concentration. The thermodynamic parameters such as ΔH and ΔS were calculated to be -86.35 kJ/mol and -165.88 J/mol · K, respectively, indicating that the interactions between EA and elastase were mainly due to van der Waals forces or hydrogen bonding. The synchronous fl uorescence spectra showed that binding of EA to elastase can induce conformational changes in elastase.

  7. Combined kinetic studies and computational analysis on kojic acid analogous as tyrosinase inhibitors.

    PubMed

    Lima, Carlyle Ribeiro; Silva, José Rogério A; de Tássia Carvalho Cardoso, Erica; Silva, Edilene O; Lameira, Jerônimo; do Nascimento, José Luiz Martins; do Socorro Barros Brasil, Davi; Alves, Cláudio N

    2014-01-01

    Tyrosinase is a key enzyme in melanin synthesis and widely distributed in plants and animals tissues. In mammals, this enzyme is related to pigment production, involved in wound healing, primary immune response and it can also contribute to catecholamines synthesis in the brain. Consequently, tyrosinase enzyme represents an attractive and selective target in the field of the medicine, cosmetics and bio-insecticides. In this paper, experimental kinetics and computational analysis were used to study the inhibition of tyrosinase by analogous of Kojic acid. The main interactions occurring between inhibitors-tyrosinase complexes and the influence of divalent cation (Cu2+) in enzymatic inhibition were investigated by using molecular docking, molecular dynamic simulations and electrostatic binding free energy by using the Linear Interaction Energy (LIE) method. The results showed that the electrostatic binding free energy are correlated with values of constant inhibition (r2 = 0.97).Thus, the model obtained here could contribute to future studies of this important system and, therefore, eventually facilitate development of tyrosinase inhibitors. PMID:25004069

  8. Identification of a D-amino acid decapeptide HIV-1 entry inhibitor

    SciTech Connect

    Boggiano, Cesar; Jiang Shibo; Lu Hong; Zhao Qian; Liu Shuwen; Binley, James; Blondelle, Sylvie E. . E-mail: sylvieb@burnham.org

    2006-09-08

    Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide DC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While DC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonal antibody and chemokine SDF-1{alpha} to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of DC13 implies additional mode(s) of action. These results suggest that DC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors.

  9. HDAC inhibition promotes both initial consolidation and reconsolidation of spatial memory in mice

    PubMed Central

    Villain, Hélène; Florian, Cédrick; Roullet, Pascal

    2016-01-01

    Accumulating evidence suggests a critical role for epigenetic regulations in long term memory (LTM) formation. Among them, post-translational modifications of proteins, as histone acetylation, are an important regulator of chromatin remodelling and gene transcription. While the implication of histone acetylation in memory consolidation is widely accepted, less is known about its role in memory reconsolidation i.e. during memory restabilization after its reactivation. In the present study, we investigated the role of histone acetylation during the initial consolidation and the reconsolidation of spatial memory, using a weak massed learning procedure in the Morris water maze paradigm in mice. Usually a weak learning is sufficient for short term memory (STM) formation, but insufficient to upgrade STM to LTM. We found that promoting histone acetylation through intra-hippocampal infusion of a class I selective histone deacetylase (HDAC) inhibitor immediately after a subthreshold spatial learning improved LTM but not STM retention. More importantly, inhibiting HDAC activity after the reactivation of a weak memory promoted specifically LTM reconsolidation without affecting post-reactivation STM. These findings argue in favour of an important r