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Sample records for inhibitor suberoylanilide hydroxamic

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

    PubMed Central

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

    2012-01-01

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

  2. Suberoylanilide hydroxamic Acid, a histone deacetylase inhibitor, alters multiple signaling pathways in hepatocellular carcinoma cell lines.

    PubMed

    Kunnimalaiyaan, Selvi; Sokolowski, Kevin; Gamblin, T Clark; Kunnimalaiyaan, Muthusamy

    2017-04-01

    Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, has preclinical efficacy in hepatocellular carcinoma (HCC), despite an unclear molecular mechanism. We sought to further investigate the effects of SAHA on HCC. We hypothesize SAHA will inhibit HCC cellular proliferation through apoptosis and aid in further profiling SAHA's effect on HCC oncogenic pathways. HCC cell lines were treated with various concentrations of SAHA. Cell proliferation was determined by MTT and colonogenic assays. Cell lysates were analyzed via Western blotting for apoptotic and oncogenic pathway markers. Caspase glo-3/7 was used to assess apoptosis. SAHA treatment demonstrated significant (<0.05) reduction in cell growth and colony formation through apoptosis and cell cycle arrest. Western analysis showed reduction in Notch, pAKT and pERK1/2 proteins. Interestingly, phosphorylated STAT3 was increased in all cell lines. SAHA inhibits Notch, AKT, and Raf-1 pathways but not the STAT3 pathway. We believe that STAT3 may lead to cancer cell progression, reducing SAHA efficacy in HCC. Therefore, combination of SAHA and STAT or Notch inhibition may be a strategy for HCC treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2016-01-01

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

  5. The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces apoptosis, down-regulates the CXCR4 chemokine receptor and impairs migration of chronic lymphocytic leukemia cells

    PubMed Central

    Stamatopoulos, Basile; Meuleman, Nathalie; De Bruyn, Cécile; Delforge, Alain; Bron, Dominique; Lagneaux, Laurence

    2010-01-01

    Background Chronic lymphocytic leukemia is a neoplastic disorder that arises largely as a result of defective apoptosis leading to chemoresistance. Stromal cell-derived factor-1 and its receptor, CXCR4, have been shown to play an important role in chronic lymphocytic leukemia cell trafficking and survival. Design and Methods Since histone acetylation is involved in the modulation of gene expression, we evaluated the effects of suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, on chronic lymphocytic leukemia cells and in particular on cell survival, CXCR4 expression, migration, and drug sensitization. Results Here, we showed that treatment with suberoylanilide hydroxamic acid (20 μM) for 48 hours induced a decrease in chronic lymphocytic leukemia cell viability via apoptosis (n=20, P=0.0032). Using specific caspase inhibitors, we demonstrated the participation of caspases-3, -6 and -8, suggesting an activation of the extrinsic pathway. Additionally, suberoylanilide hydroxamic acid significantly decreased CXCR4 mRNA (n=10, P=0.0010) and protein expression (n=40, P<0.0001). As a result, chronic lymphocytic leukemia cell migration in response to stromal cell-derived factor-1 (n=23, P<0.0001) or through bone marrow stromal cells was dramatically impaired. Consequently, suberoylanilide hydroxamic acid reduced the protective effect of the microenvironment and thus sensitized chronic lymphocytic leukemia cells to chemotherapy such as fludarabine. Conclusions In conclusion, suberoylanilide hydroxamic acid induces apoptosis in chronic lymphocytic leukemia cells via the extrinsic pathway and down-regulates CXCR4 expression leading to decreased cell migration. Suberoylanilide hydroxamic acid in combination with other drugs represents a promising therapeutic approach to inhibiting migration, chronic lymphocytic leukemia cell survival and potentially overcoming drug resistance. PMID:20145270

  6. 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

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

    PubMed

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

    2011-01-01

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

  8. The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces growth inhibition and enhances taxol-induced cell death in breast cancer.

    PubMed

    Shi, Yi-kang; Li, Zhong-hua; Han, Xi-qian; Yi, Ji-hu; Wang, Zhen-hua; Hou, Jing-li; Feng, Cong-ran; Fang, Qing-hong; Wang, Hui-hui; Zhang, Peng-fei; Wang, Feng-shan; Shen, Jie; Wang, Peng

    2010-11-01

    The histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA) enhances taxol-induced antitumor effects against some human cancer cells. The aim of this study is to investigate whether SAHA can enhance taxol-induced cell death against human breast cancer cells and to illustrate the mechanism in detail. A panel of eight human breast cancer cell lines and an immortalized human breast epithelial cell line were used to determine the inhibitory effects of SAHA, taxol, or their combination by MTT assay. The effects of SAHA with or without taxol on cell cycle distributions, apoptosis, and protein expressions were also examined. The inhibitory effects on tumor growth were characterized in vivo in BALB/c nude mice bearing a breast cancer xenograft model. Taxol-resistant and multi-resistant breast cancer cells were as sensitive to SAHA as taxol-sensitive breast cancer cells. A dose-dependent synergistic growth inhibition was found in all the tested breast cancer cell lines treated with the SAHA/taxol combinations. The synergetic effect was also observed in the in vivo xenograft tumor model. The cell cycle analysis and apoptosis assay showed that the synergistic effects resulted from enhanced G2/M arrest and apoptosis. SAHA increased the anti-tumor effects of taxol in breast cancer in vitro and in vivo. The combination of SAHA and taxol may have therapeutic potential in the treatment of breast cancer.

  9. Wortmannilactones I-L, new NADH-fumarate reductase inhibitors, induced by adding suberoylanilide hydroxamic acid to the culture medium of Talaromyces wortmannii.

    PubMed

    Liu, Wen-Cai; Wang, Yi-Yu; Liu, Jun-Hui; Ke, Ai-Bing; Zheng, Zhi-Hui; Lu, Xin-Hua; Luan, Yu-Shi; Xiu, Zhi-Long; Dong, Yue-Sheng

    2016-11-01

    With the aim of finding more potential inhibitors against NADH-fumarate reductase (specific target for treating helminthiasis and cancer) from natural resources, Talaromyces wortmannii was treated with the epigenome regulatory agent suberoylanilide hydroxamic acid, which resulted in the isolation of four new wortmannilactones derivatives (wortmannilactones I-L, 1-4). The structures of these new compounds were elucidated based on IR, HRESIMS and NMR spectroscopic data analyses. These four new compounds showed potent inhibitory activity against NADH-fumarate reductase with the IC50 values ranging from 0.84 to 1.35μM.

  10. The Histone-Deacetylase-Inhibitor Suberoylanilide Hydroxamic Acid Promotes Dental Pulp Repair Mechanisms Through Modulation of Matrix Metalloproteinase-13 Activity.

    PubMed

    Duncan, Henry F; Smith, Anthony J; Fleming, Garry J P; Partridge, Nicola C; Shimizu, Emi; Moran, Gary P; Cooper, Paul R

    2016-04-01

    Direct application of histone-deacetylase-inhibitors (HDACis) to dental pulp cells (DPCs) induces chromatin changes, promoting gene expression and cellular-reparative events. We have previously demonstrated that HDACis (valproic acid, trichostatin A) increase mineralization in dental papillae-derived cell-lines and primary DPCs by stimulation of dentinogenic gene expression. Here, we investigated novel genes regulated by the HDACi, suberoylanilide hydroxamic acid (SAHA), to identify new pathways contributing to DPC differentiation. SAHA significantly compromised DPC viability only at relatively high concentrations (5 μM); while low concentrations (1 μM) SAHA did not increase apoptosis. HDACi-exposure for 24 h induced mineralization-per-cell dose-dependently after 2 weeks; however, constant 14d SAHA-exposure inhibited mineralization. Microarray analysis (24 h and 14 days) of SAHA exposed cultures highlighted that 764 transcripts showed a significant >2.0-fold change at 24 h, which reduced to 36 genes at 14 days. 59% of genes were down-regulated at 24 h and 36% at 14 days, respectively. Pathway analysis indicated SAHA increased expression of members of the matrix metalloproteinase (MMP) family. Furthermore, SAHA-supplementation increased MMP-13 protein expression (7 d, 14 days) and enzyme activity (48 h, 14 days). Selective MMP-13-inhibition (MMP-13i) dose-dependently accelerated mineralization in both SAHA-treated and non-treated cultures. MMP-13i-supplementation promoted expression of several mineralization-associated markers, however, HDACi-induced cell migration and wound healing were impaired. Data demonstrate that short-term low-dose SAHA-exposure promotes mineralization in DPCs by modulating gene pathways and tissue proteases. MMP-13i further increased mineralization-associated events, but decreased HDACi cell migration indicating a specific role for MMP-13 in pulpal repair processes. Pharmacological inhibition of HDAC and MMP may

  11. Clinical experience with the novel histone deacetylase inhibitor vorinostat (suberoylanilide hydroxamic acid) in patients with relapsed lymphoma

    PubMed Central

    O'Connor, O A

    2006-01-01

    Preclinical studies indicate that vorinostat (suberoylanilide hydroxamic acid or SAHA) inhibits histone deacetylase (HDAC) activity, increases acetylated histones H2a, H2b, H3, and H4, and thereby induces differentiation and apoptosis in a variety of tumour cell lines, including murine erythroleukaemia, human bladder transitional cell carcinoma, and human breast adenocarcinoma. On the basis of these favourable preclinical findings, vorinostat has been selected as a candidate for clinical development with the potential to treat patients with selected malignances, including Hodgkin's disease and non-Hodgkin's lymphomas. Phase I clinical trials in patients with haematological malignances and solid tumours showed that both intravenous (i.v.) and oral formulations of vorinostat are well tolerated, can inhibit HDAC activity in peripheral blood mononuclear cells and tumour tissue biopsies, and produce objective tumour regression and symptomatic improvement with little clinical toxicity. The dose-limiting toxicities (DLT) of i.v. vorinostat were primarily haematologic and were rapidly reversible within 4–5 days of therapy cessation. In contrast, the DLT for oral vorinostat were primarily non-haematologic (including dehydration, anorexia, diarrhoea, fatigue) and were also rapidly reversible, usually within 3 days. Further research is warranted to optimise the dosing schedule for vorinostat, particularly with respect to dose, timing of administration, and duration of therapy, and to fully delineate the mechanism(s) of antitumour effect of vorinostat in various types of malignances. Several phase II studies are currently ongoing in patients with haematological malignances and solid tumours.

  12. The histone deacetylase inhibitor and chemotherapeutic agent suberoylanilide hydroxamic acid (SAHA) induces a cell-death pathway characterized by cleavage of Bid and production of reactive oxygen species

    PubMed Central

    Ruefli, Astrid A.; Ausserlechner, Michael J.; Bernhard, David; Sutton, Vivien R.; Tainton, Kellie M.; Kofler, Reinhard; Smyth, Mark J.; Johnstone, Ricky W.

    2001-01-01

    Many chemotherapeutic agents induce mitochondrial-membrane disruption to initiate apoptosis. However, the upstream events leading to drug-induced mitochondrial perturbation have remained poorly defined. We have used a variety of physiological and pharmacological inhibitors of distinct apoptotic pathways to analyze the manner by which suberoylanilide hydroxamic acid (SAHA), a chemotherapeutic agent and histone deacetylase inhibitor, induces cell death. We demonstrate that SAHA initiates cell death by inducing mitochondria-mediated death pathways characterized by cytochrome c release and the production of reactive oxygen species, and does not require the activation of key caspases such as caspase-8 or -3. We provide evidence that mitochondrial disruption is achieved by means of the cleavage of the BH3-only proapoptotic Bcl-2 family member Bid. SAHA-induced Bid cleavage was not blocked by caspase inhibitors or the overexpression of Bcl-2 but did require the transcriptional regulatory activity of SAHA. These data provide evidence of a mechanism of cell death mediated by transcriptional events that result in the cleavage of Bid, disruption of the mitochondrial membrane, and production of reactive oxygen species to induce cell death. PMID:11535817

  13. Effects of Treatment with Suppressive Combination Antiretroviral Drug Therapy and the Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid; (SAHA) on SIV-Infected Chinese Rhesus Macaques

    PubMed Central

    Ling, Binhua; Piatak, Michael; Rogers, Linda; Johnson, Ann-Marie; Russell-Lodrigue, Kasi; Hazuda, Daria J.; Lifson, Jeffrey D.; Veazey, Ronald S.

    2014-01-01

    Objectives Viral reservoirs–persistent residual virus despite combination antiretroviral therapy (cART)–remain an obstacle to cure of HIV-1 infection. Difficulty studying reservoirs in patients underscores the need for animal models that mimics HIV infected humans on cART. We studied SIV-infected Chinese-origin rhesus macaques (Ch-RM) treated with intensive combination antiretroviral therapy (cART) and 3 weeks of treatment with the histone deacetyalse inhibitor, suberoylanilide hydroxamic acid (SAHA). Methods SIVmac251 infected Ch-RM received reverse transcriptase inhibitors PMPA and FTC and integrase inhibitor L-870812 beginning 7 weeks post infection. Integrase inhibitor L-900564 and boosted protease inhibitor treatment with Darunavir and Ritonavir were added later. cART was continued for 45 weeks, with daily SAHA administered for the last 3 weeks, followed by euthanasia/necropsy. Plasma viral RNA and cell/tissue-associated SIV gag RNA and DNA were quantified by qRT-PCR/qPCR, with flow cytometry monitoring changes in immune cell populations. Results Upon cART initiation, plasma viremia declined, remaining <30 SIV RNA copy Eq/ml during cART, with occasional blips. Decreased viral replication was associated with decreased immune activation and partial restoration of intestinal CD4+ T cells. SAHA was well tolerated but did not result in demonstrable treatment-associated changes in plasma or cell associated viral parameters. Conclusions The ability to achieve and sustain virological suppression makes cART-suppressed, SIV-infected Ch-RM a potentially useful model to evaluate interventions targeting residual virus. However, despite intensive cART over one year, persistent viral DNA and RNA remained in tissues of all three animals. While well tolerated, three weeks of SAHA treatment did not demonstrably impact viral RNA levels in plasma or tissues; perhaps reflecting dosing, sampling and assay limitations. PMID:25033210

  14. Synergistic antineoplastic effect of DLC1 tumor suppressor protein and histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), on prostate and liver cancer cells: perspectives for therapeutics.

    PubMed

    Zhou, Xiaoling; Yang, Xu-Yu; Popescu, Nicholas C

    2010-04-01

    Inactivation of tumor suppressor genes is a major contributing alteration in the initiation or progression of cancer. The human tumor suppressor gene DLC1 (deleted in liver cancer 1) is frequently downregulated or silenced in multiple cancers, predominantly by epigenetic mechanisms. With the current considerable interest and progress in epigenetic therapy, a number of promising antineoplastic agents, particularly histone deacetylase (HDAC) inhibitors, have been developed and used successfully in clinical trials. Both DLC1 and HDAC inhibitors exert antineoplastic functions, and their combined action could be exploited for a more effective cancer therapy. To evaluate the potential benefits of this approach, we examined the antineoplastic effects of adenoviral (Ad)-DLC1-mediated transduction and exposure to suberoylanilide hydroxamic acid (SAHA), a powerful HDAC inhibitor, in two human cancer cell lines that lack intrinsic DLC1 expression, 22Rv1 prostate cancer cells and 7703K human hepatocellular carcinoma cells. Consistent with the oncosuppressive function of DLC1 in several cancers, including prostate and liver cancer, transduction of 22Rv1 and 7703K cells with an Ad-DLC1 expression vector resulted in alterations of cell morphology, induction of apoptosis, and inhibition of cell proliferation, migration, and anchorage-independent growth. A low concentration of SAHA (5 microM) efficiently restored the expression of DLC1 in 22Rv1 cells that lack DLC1 expression due to histone deacetylation but had a minimal effect in 7703K cells in which silencing of the DLC1 gene is due mainly to promoter hypermethylation. Regardless of the epigenetic mechanism of DLC1 inactivation, SAHA treatment of DLC1-transduced cells had a synergistic inhibitory effect on tumor cell proliferation and tumorigenesis in both cell lines. In 22Rv1 cells, this combination regimen nearly abolished the formation of colonies in semisolid media as a measure of tumorigenicity in vitro. Current in vitro

  15. In vivo efficacy of the histone deacetylase inhibitor suberoylanilide hydroxamic acid in combination with radiotherapy in a malignant rhabdoid tumor mouse model

    PubMed Central

    2012-01-01

    Purpose Histone deacetylase inhibitors are promising new substances in cancer therapy and have also been shown to sensitize different tumor cells to irradiation (XRT). We explored the effect as well as the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) in vivo in a malignant rhabdoid tumor (MRT) mouse model. Methods and material Potential radiosensitization by SAHA was assessed in MRT xenografts by analysis of tumor growth delay, necrosis (HE), apoptosis (TUNEL), proliferation (ki-67) and γH2AX expression as well as dynamic 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG -PET) after treatment with either SAHA alone, single-dose (10 Gy) or fractionated XRT (3 × 3Gy) solely as well as in combination with SAHA compared to controls. Results SAHA only had no significant effect on tumor growth. Combination of SAHA for 8 days with single-dose XRT resulted in a higher number of complete remissions, but failed to prove a significant growth delay compared to XRT only. In contrast fractionated XRT plus SAHA for 3 weeks did induce significant tumor growth delay in MRT-xenografts. The histological examination showed a significant effect of XRT in tumor necrosis, expression of Ki-67, γH2AX and apoptosis. SAHA only had no significant effect in the histological examination. Comparison of xenografts treated with XRT and XRT plus SAHA revealed a significantly increased γH2AX expression and apoptosis induction in the mice tumors after combination treatment with single-dose as well as fractionated XRT. The combination of SAHA with XRT showed a tendency to increased necrosis and decrease of proliferation compared to XRT only, which, however, was not significant. The 18F-FDG-PET results showed no significant differences in the standard uptake value or glucose transport kinetics after either treatment. Conclusion SAHA did not have a significant effect alone, but proved to enhance the effect of XRT in our MRT in vivo model. PMID:22458853

  16. 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.

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2010-03-25

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

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

    PubMed

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

    2015-03-07

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

  20. Suberoylanilide hydroxamic acid (SAHA) at subtoxic concentrations increases the adhesivity of human leukemic cells to fibronectin.

    PubMed

    Kuzelová, Katerina; Pluskalová, Michaela; Brodská, Barbora; Otevrelová, Petra; Elknerová, Klára; Grebenová, Dana; Hrkal, Zbynek

    2010-01-01

    Suberoylanilide hydroxamic acid (SAHA) is an inhibitor of histone deacetylases (HDACs) which is being introduced into clinic for the treatment of hematological diseases. We studied the effect of this compound on six human hematopoietic cell lines (JURL-MK1, K562, CML-T1, Karpas-299, HL-60, and ML-2) as well as on normal human lymphocytes and on leukemic primary cells. SAHA induced dose-dependent and cell type-dependent cell death which displayed apoptotic features (caspase-3 activation and apoptotic DNA fragmentation) in most cell types including the normal lymphocytes. At subtoxic concentrations (0.5-1 microM), SAHA increased the cell adhesivity to fibronectin (FN) in all leukemia/lymphoma-derived cell lines but not in normal lymphocytes. This increase was accompanied by an enhanced expression of integrin beta1 and paxillin, an essential constituent of focal adhesion complexes, both at the protein and mRNA level. On the other hand, the inhibition of ROCK protein, an important regulator of cytoskeleton structure, had no consistent effect on SAHA-induced increase in the cell adhesivity. The promotion of cell adhesivity to FN seems to be specific for SAHA as we observed no such effects with other HDAC inhibitors (trichostatin A and sodium butyrate).

  1. A novel suberoylanilide hydroxamic acid histone deacetylase inhibitor derivative, N25, exhibiting improved antitumor activity in both human U251 and H460 cells.

    PubMed

    Zhang, Song; Huang, Wei-Bin; Wu, Li; Wang, Lai-You; Ye, Lian-Bao; Feng, Bing-Hong

    2014-01-01

    N1- (2, 5-dimethoxyphenyl)-N(8)-hydroxyoctanediamide (N25) is a novel SAHA cap derivative of HDACi, with a patent (No. CN 103159646). This invention is a hydroxamic acid compound with a structural formula of RNHCO(CH2)6CONHOH (wherein R=2, 5dimethoxyaniline), a pharmaceutically acceptable salt which is soluble. In the present study, we investigated the effects of N25 with regard to drug distribution and molecular docking, and anti-proliferation, apoptosis, cell cycling, and LD50. First, we designed a molecular approach for modeling selected SAHA derivatives based on available structural information regarding human HDAC8 in complex with SAHA (PDB code 1T69). N25 was found to be stabilized by direct interaction with the HDAC8. Anti-proliferative activity was observed in human glioma U251, U87, T98G cells and human lung cancer H460, A549, H1299 cells at moderate concentrations (0.5-30 μM). Compared with SAHA, N25 displayed an increased antitumor activity in U251 and H460 cells. We further analyzed cell death mechanisms activated by N25 in U251 and H460 cells. N25 significantly increased acetylation of Histone 3 and inhibited HDAC4. On RT-PCR analysis, N25 increased the mRNA levels of p21, however, decreased the levels of p53. These resulted in promotion of apoptosis, inducing G0/G1 arrest in U251 cells and G2/M arrest in H460 cells in a time-dependent and dose- dependent manner. In addition, N25 was able to distribute to brain tissue through the blood-brain barrier of mice (LD50: 240.840 mg/kg). In conclusion, our findings demonstrate that N25 will provide an invaluable tool to investigate the molecular mechanism with potential chemotherapeutic value in several malignancies, especially human glioma.

  2. Suberoylanilide Hydroxamic Acid (SAHA)-Induced Dynamics of a Human Histone Deacetylase Protein Interaction Network*

    PubMed Central

    Sardiu, Mihaela E.; Smith, Karen T.; Groppe, Brad D.; Gilmore, Joshua M.; Saraf, Anita; Egidy, Rhonda; Peak, Allison; Seidel, Chris W.; Florens, Laurence; Workman, Jerry L.; Washburn, Michael P.

    2014-01-01

    Histone deacetylases (HDACs) are targets for cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is an HDAC inhibitor approved by the U.S. Food and Drug Administration for the treatment of cutaneous T-cell lymphoma. To obtain a better mechanistic understanding of the Sin3/HDAC complex in cancer, we extended its protein–protein interaction network and identified a mutually exclusive pair within the complex. We then assessed the effects of SAHA on the disruption of the complex network through six homologous baits. SAHA perturbs multiple protein interactions and therefore compromises the composition of large parts of the Sin3/HDAC network. A comparison of the effect of SAHA treatment on gene expression in breast cancer cells to a knockdown of the ING2 subunit indicated that a portion of the anticancer effects of SAHA may be attributed to the disruption of ING2's association with the complex. Our dynamic protein interaction network resource provides novel insights into the molecular mechanism of SAHA action and demonstrates the potential for drugs to rewire networks. PMID:25073741

  3. Single Conformation Spectroscopy of Suberoylanilide Hydroxamic Acid: a Molecule Bites its Tail

    NASA Astrophysics Data System (ADS)

    Zhang, Di; Dean, Jacob; Zwier, Timothy S.

    2012-06-01

    Suberoylanilide hydroxamic acid (C_6H_5NHCO(CH_2)_6CONHOH, SAHA) is a histone deacetylase inhibitor approved by the FDA for the treatment of cutaneous T-cell lymphoma. With one hydrogen bonding group adjacent to ring and the other at the end of a long C_6 hydrocarbon tail, SAHA possesses an interesting potential energy landscape to be probed by single-conformation methods. A large number of extended structures favored by entropy are offset by a few structures in which head-to-tail or tail-to-head H-bonds close a large loop between the two groups separated by the C_6 chain. We use laser desorption to bring SAHA into the gas phase and cool it in a supersonic expansion before interrogation with resonant two-photon ionization. Single-conformation UV spectra in the S_0-S_1 region and infrared spectra in the hydride stretch region were recorded using IR-UV hole-burning and resonant ion-dip infrared (RIDIR) spectroscopies, respectively. Four different conformers were observed and spectroscopically characterized. Comparison of the experimental IR spectra with density functional theory (DFT) calculations leads to assignments for two of the major conformers, which adopt head-to-tail and tail-to-head binding patterns. The implication of the observed structures for the folding landscape and configuration preference of SAHA will be discussed.

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

    PubMed

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

    2013-01-01

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

  5. Suberoylanilide hydroxamic acid (SAHA) enhances olaparib activity by targeting homologous recombination DNA repair in ovarian cancer.

    PubMed

    Konstantinopoulos, Panagiotis A; Wilson, Andrew J; Saskowski, Jeanette; Wass, Erica; Khabele, Dineo

    2014-06-01

    Approximately 50% of serous epithelial ovarian cancers (EOC) contain molecular defects in homologous recombination (HR) DNA repair pathways. Poly(ADP-ribose) polymerase inhibitors (PARPi) have efficacy in HR-deficient, but not in HR-proficient, EOC tumors as a single agent. Our goal was to determine whether the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), can sensitize HR-proficient ovarian cancer cells to the PARPi AZD-2281 (olaparib). Ovarian cancer cell lines (SKOV-3, OVCAR-8, NCI/ADR-Res, UWB1.289 BRCA1null and UWB1.289+BRCA1 wild-type) were treated with saline vehicle, olaparib, SAHA or olaparib/SAHA. Sulforhodamine B (SRB) assessed cytotoxicity and immunofluorescence and Western blot assays assessed markers of apoptosis (cleaved PARP) and DNA damage (pH2AX and RAD51). Drug effects were also tested in SKOV-3 xenografts in Nude mice. Affymetrix microarray experiments were performed in vehicle and SAHA-treated SKOV-3 cells. In a microarray analysis, SAHA induced coordinated down-regulation of HR pathway genes, including RAD51 and BRCA1. Nuclear co-expression of RAD51 and pH2AX, a marker of efficient HR repair, was reduced approximately 40% by SAHA treatment alone and combined with olaparib. SAHA combined with olaparib induced apoptosis and pH2AX expression to a greater extent than either drug alone. Olaparib reduced cell viability at increasing concentrations and SAHA enhanced these effects in 4 of 5 cell lines, including BRCA1 null and wild-type cells, in vitro and in SKOV-3 xenografts in vivo. These results provide preclinical rationale for targeting DNA damage response pathways by combining small molecule PARPi with HDACi as a mechanism for reducing HR efficiency in ovarian cancer. Copyright © 2014. Published by Elsevier Inc.

  6. Suberoylanilide Hydroxamic Acid (SAHA) enhances olaparib activity by targeting homologous recombination DNA repair in ovarian cancer

    PubMed Central

    Konstantinopoulos, Panagiotis A.; Wilson, Andrew J.; Saskowski, Jeanette; Wass, Erica; Khabele, Dineo

    2015-01-01

    Objectives Approximately 50% of serous epithelial ovarian cancers (EOC) contain molecular defects in homologous recombination (HR) DNA repair pathways. Poly(ADP-ribose) polymerase inhibitors (PARPi) have efficacy in HR-deficient, but not HR-proficient, EOC tumors as a single agent. Our goal was to determine whether the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), can sensitize HR-proficient ovarian cancer cells to the PARPi AZD-2281 (olaparib). Methods Ovarian cancer cell lines (SKOV-3, OVCAR-8, NCI/ADR-Res, UWB1.289 BRCA1null and UWB1.289 + BRCA1 wild-type) were treated with saline vehicle, olaparib, SAHA or olaparib/SAHA. Sulforhodamine B (SRB) assessed cytotoxicity and immunofluorescence and Western blot assays assessed markers of apoptosis (cleaved PARP) and DNA damage (pH2AX and RAD51). Drug effects were also tested in SKOV-3 xenografts in Nude mice. Affymetrix microarray experiments were performed in vehicle and SAHA-treated SKOV-3 cells. Results In a microarray analysis, SAHA induced coordinated down-regulation of HR pathway genes, including RAD51 and BRCA1. Nuclear co-expression of RAD51 and pH2AX, a marker of efficient HR repair, was reduced approximately 40% by SAHA treatment alone and combined with olaparib. SAHA combined with olaparib induced apoptosis and pH2AX expression to a greater extent than either drug alone. Olaparib reduced cell viability at increasing concentrations and SAHA enhanced these effects in 4 of 5 cell lines, including BRCA1 null and wild-type cells, in vitro and in SKOV-3 xenografts in vivo. Conclusions These results provide preclinical rationale for targeting DNA damage response pathways by combining small molecule PARPi with HDACi as a mechanism for reducing HR efficiency in ovarian cancer. PMID:24631446

  7. Suberoylanilide hydroxamic acid as a potential therapeutic agent for human breast cancer treatment.

    PubMed Central

    Huang, L.; Pardee, A. B.

    2000-01-01

    BACKGROUND: Suberoylanilide hydroxamic acid (SAHA) is a prototype of the newly developed, second-generation, hybrid polar compounds. It is a novel histone deacetylase inhibitor with high potency for inducing cell differentiation of cultured murine erythroleukemia cells. Studies with SAHA have primarily been performed with hematopoietic tumor cells. Here we extent these studies with SAHA to human breast cancer cell lines in an attempt to find better therapeutic agents for breast cancer treatment. MATERIALS AND METHODS: Human breast cancer cell lines, MCF7, MDA-MB-231, and MDA-MB-435, as well as normal cells, including the normal breast epithelial cell line MCF-10A, and fibroblasts, were treated with SAHA. Cells assayed for cell survival by using trypan blue exclusion assay, colony formation assay, and cell cycle and apoptosis analysis. The effects of SAHA on cell cycle and apoptosis regulatory proteins were examined by Western blots analysis. The identification of additional target genes was carried out by differential display (DD) and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: SAHA inhibited clonogenic growth of MCF7, MDA-MB-231, and MDA-MB-435 breast cancer cells. These cells were more sensitive to SAHA-mediated cytotoxic effects than normal breast epithelial cells and fibroblasts. The cytotoxic effects of SAHA on breast cancer cells were manifested by G1 and G2/M cell cycle arrest and eventual apoptosis. The pan-caspase inhibitor, Z-VAD.fmk, blocked SAHA-induced cell death, DNA laddering, and cleavage of poly(ADP-ribose) polymerase, indicating the involvement of caspases in SAHA-mediated apoptosis. In addition, SAHA modulated cell cycle and apoptosis regulatory proteins. For example, cyclin-dependent kinase (CDK) inhibitors p21WAF1/Cip1 and p27Kip1 were induced, and retinoblastoma protein pRb was hypophosphorylated. Moreover, SAHA induced several genes associated with differentiation and/ or growth inhibition. These genes encode gelsolin

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

    PubMed Central

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

    2007-01-01

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

  9. Protective effect of suberoylanilide hydroxamic acid against LPS-induced septic shock in rodents.

    PubMed

    Li, Yongqing; Liu, Baoling; Zhao, Hang; Sailhamer, Elizabeth A; Fukudome, Eugene Y; Zhang, Xiaobo; Kheirbek, Tareq; Finkelstein, Robert A; Velmahos, George C; deMoya, Marc; Hales, Charles A; Alam, Hasan B

    2009-11-01

    We have recently found that suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, improves survival in a lethal model of hemorrhagic shock in rats. The purpose of the present study was to determine whether SAHA treatment would prevent LPS-induced septic shock and improve the survival in a murine model. C57BL/6J mice were randomly divided into two groups. Experimental mice were given intraperitoneal SAHA (50 mg/kg) in vehicle dimethyl sulfoxide fluid (n = 10). The control mice (n = 10) received vehicle dimethyl sulfoxide only. They were injected with LPS (20 mg/kg, i.p.) 2 h later, and the animals from the treatment group were given a second dose of SAHA. Survival was monitored during the next 7 days. In a parallel study, mice treated with or without SAHA were subjected to LPS insult while normal (sham) mice serviced as controls. 1) Lungs were harvested at 3 and 48 h for analysis of gene expression and pathologic changes, respectively; 2) spleens were isolated for analysis of neutrophilic cell population. In addition, RAW264.7 mouse macrophages were cultured to assess the effects of SAHA on LPS-induced inflammation in vitro. All mice in the control group that were subjected to LPS challenge died in less than 48 h. However, SAHA-treated animals displayed a significantly higher 1-week survival rate (87.5%) compared with the control group (0%). Moreover, LPS insult decreased the acetylation of histone proteins (H2A, H2B, and H3), elevated the levels of TNF-alpha in vivo (circulation) and in vitro (culture medium), increased the neutrophilic cell population in the spleen, enhanced the expression of TNF-alpha and IL-1beta genes in lung tissue, and augmented the pulmonary neutrophil infiltration. In contrast, SAHA treatment markedly attenuated all of these LPS-induced alterations. We report for the first time that administration of SAHA (50 mg/kg) significantly attenuates a variety of inflammatory markers and improves long-term survival after a lethal

  10. Synthesis and Anti-tumor Activities of Novel Phenyl Substituted Suberoylanilide Hydroxamic Acid Derivatives Against Human Cancer Cells.

    PubMed

    Xie, Rui; Shi, Jinghua; Qu, Yue; Tang, Pingwah; Wu, Xinying; Yang, Ming; Yuan, Qipeng

    2015-01-01

    A facile and atom-economical boric acid catalyzed direct amidation without any coupling agents for the preparation of Suberoylanilide Hydroxamic Acid (SAHA) and SAHA-based inhibitors targeting anti-proliferation of cancer cells is described. It is applicable to the preparation of SAHA-based inhibitors having an unprotected hydroxyl group in the phenyl ring without the need of the protection. The in-vitro assays data indicate that the nature and the position of the substituents (activating and/or deactivating) in the capping group (phenyl ring) of SAHA-based inhibitors synthesized in this study have a vital impact on the potency of anti-proliferative activity against cancer cells. With low toxicity toward the normal cells, a number of synthesized SAHA-based inhibitors with two substituents in the phenyl ring possess higher antiproliferative activity than SAHA and Cisplatin toward six studied cancer cell lines: A375 human skin cancer cells, A549 human lung cancer cells, MGC80-3 human gastric cancer cells, H460 human lung cancer cells, H1299 human lung cancer cells, and HepG2 human liver cancer cells. Cisplatin is a common chemotherapeutic drug with high cytotoxicity for a variety of cancer treatments. The inhibitors provided in this study might signify future therapeutic drugs for cancer treatment.

  11. Suberoylanilide hydroxamic acid suppresses hepatic stellate cells activation by HMGB1 dependent reduction of NF-κB1

    PubMed Central

    Wang, Wenwen; Yan, Min; Ji, Qiuhong; Lu, Jinbiao; Ji, Yuhua

    2015-01-01

    Hepatic stellate cells (HSCs) activation is essential to the pathogenesis of liver fibrosis. Exploring drugs targeting HSC activation is a promising anti-fibrotic strategy. In the present study, we found suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, prominently suppressed the activation phenotype of a human hepatic stellate cell line—LX2. The production of collagen type I and α-smooth muscle actin (α-SMA) as well as the proliferation and migration of LX2 cells were significantly reduced by SAHA treatment. To determine the molecular mechanisms underlying this suppression, genome wild gene regulation by SAHA was determined by Affymetrix 1.0 human cDNA array. Upon SAHA treatment, the abundance of 331 genes was up-regulated and 173 genes was down-regulated in LX2 cells. Bioinformatic analyses of these altered genes highlighted the high mobility group box 1 (HMGB1) pathway was one of the most relevant pathways that contributed to SAHA induced suppression of HSCs activation. Further studies demonstrated the increased acetylation of intracellular HMGB1 in SAHA treated HSCs, and this increasing is most likely to be responsible for SAHA induced down-regulation of nuclear factor kappa B1 (NF-κB1) and is one of the main underlying mechanisms for the therapeutic effect of SAHA for liver fibrosis. PMID:26557438

  12. Metabolic changes in rat serum after administration of suberoylanilide hydroxamic acid and discriminated by SVM.

    PubMed

    Yu, J; Wu, H; Lin, Z; Su, K; Zhang, J; Sun, F; Wang, X; Wen, C; Cao, H; Hu, L

    2017-01-01

    Suberoylanilide hydroxamic acid (SAHA) exerts marked anticancer effects via promotion of apoptosis, cell cycle arrest, and prevention of oncogene expression. In this study, serum metabolomics and artificial intelligence recognition were used to investigate SAHA toxicity. Forty rats (220 ± 20 g) were randomly divided into control and three SAHA groups (low, medium, and high); the experimental groups were treated with 12.3, 24.5, or 49.0 mg kg(-1) SAHA once a day via intragastric administration. After 7 days, blood samples from the four groups were collected and analyzed by gas chromatography-mass spectrometry, and pathological changes in the liver were examined using microscopy. The results showed that increased levels of urea, oleic acid, and glutaconic acid were the most significant indicators of toxicity. Octadecanoic acid, pentadecanoic acid, glycerol, propanoic acid, and uric acid levels were lower in the high SAHA group. Microscopic observation revealed no obvious damage to the liver. Based on these data, a support vector machine (SVM) discrimination model was established that recognized the metabolic changes in the three SAHA groups and the control group with 100% accuracy. In conclusion, the main toxicity caused by SAHA was due to excessive metabolism of saturated fatty acids, which could be recognized by an SVM model.

  13. Suberoylanilide hydroxamic acid-induced HeLa cell death is closely correlated with oxidative stress and thioredoxin 1 levels.

    PubMed

    You, Bo Ra; Park, Woo Hyun

    2014-05-01

    Suberoylanilide hydroxamic acid (SAHA) is a histone deacetylase (HDAC) inhibitor which has anticancer effects. We evaluated the growth inhibitory effects of SAHA on HeLa cervical cancer cells in relation to reactive oxygen species (ROS) levels. SAHA inhibited the growth of HeLa cells with an IC(50) of approximately 10 µM at 24 h, and induced apoptosis which was accompanied by the cleavage of PARP, caspase-3 activation and loss of mitochondrial membrane potential (MMP; ∆ψ(m)). All the tested caspase inhibitors prevented HeLa cell death induced by SAHA whereas TNF-α intensified apoptotic cell death in SAHA-treated HeLa cells. With respect to ROS and glutathione (GSH) levels, SAHA increased ROS levels, especially mitochondrial O(2)•- in HeLa cells and also induced GSH depletion. Caspase inhibitors reduced the levels of ROS and GSH depletion in SAHA-treated HeLa cells whereas TNF-α enhanced the levels in these cells. The well-known antioxidant N-acetyl cysteine (NAC) attenuated cell death and an increase in ROS levels was caused by SAHA. Moreover, SAHA decreased the levels of thioredoxin 1 (Trx1) in HeLa cells. While the downregulation of Trx1 enhanced cell death and ROS levels in SAHA-treated HeLa cells, the overexpression of Trx1 attenuated the levels in these cells. In conclusion, SAHA inhibited the growth of HeLa cell via caspase-dependent apoptosis, which was influenced by the mitochondrial O(2)•- and Trx1 levels.

  14. Altering histone acetylation status in donor cells with suberoylanilide hydroxamic acid does not affect dog cloning efficiency.

    PubMed

    Kim, Min Jung; Oh, Hyun Ju; Kim, Geon A; Suh, Han Na; Jo, Young Kwang; Choi, Yoo Bin; Kim, Dong Hoon; Han, Ho Jae; Lee, Byeong Chun

    2015-10-15

    Although dog cloning technology has been applied to conservation of endangered canids, propagation of elite dogs, and production of transgenic dogs, the efficiency of cloning is still very low. To help overcome this problem, we evaluated the effect of treating donor cells with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on dog cloning efficiency. Relative messenger RNA expressions of the bax1/bcl2 ratio and Dnmt1 in fibroblasts treated with different concentrations (0, 1, 10, 50 μM) of SAHA and durations (0, 20, 44 hours) were compared. Treatment with 1 μM for 20 hours showed significantly lower bax1/bcl2 and Dnmt1 transcript abundance. Acetylation of H3K9 was significantly increased after SAHA treatment, but H4K5, H4K8 and H4K16 were not changed. After SCNT using control or donor cells treated with SAHA, a total of 76 and 64 cloned embryos were transferred to seven and five recipients, respectively. Three fetuses were diagnosed in both control and SAHA-treated groups by ultrasonography 29 days after the embryo transfer, but there was no significant difference in the pregnancy rate (4.2% vs. 4.3%). In conclusion, although SAHA treatment as used in this study significantly decreased bax1/bcl2 and Dnmt1 transcripts of donor nuclei, as well as increased H3 acetylation, it was not enough to increase in vivo developmental competence of cloned dog embryos. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Enhanced suppression of tumor growth by concomitant treatment of human lung cancer cells with suberoylanilide hydroxamic acid and arsenic trioxide

    SciTech Connect

    Chien, Chia-Wen; Yao, Ju-Hsien; Chang, Shih-Yu; Lee, Pei-Chih; Lee, Te-Chang

    2011-11-15

    The efficacy of arsenic trioxide (ATO) against acute promyelocytic leukemia (APL) and relapsed APL has been well documented. ATO may cause DNA damage by generating reactive oxygen intermediates. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, modulates gene and protein expression via histone-dependent or -independent pathways that may result in chromatin decondensation, cell cycle arrest, differentiation, and apoptosis. We investigated whether ATO and SAHA act synergistically to enhance the death of cancer cells. Our current findings showed that combined treatment with ATO and SAHA resulted in enhanced suppression of non-small-cell lung carcinoma in vitro in H1299 cells and in vivo in a xenograft mouse model. Flow cytometric analysis of annexin V+ cells showed that apoptotic cell death was significantly enhanced after combined treatment with ATO and SAHA. At the doses used, ATO did not interfere with cell cycle progression, but SAHA induced p21 expression and led to G1 arrest. A Comet assay demonstrated that ATO, but not SAHA, induced DNA strand breaks in H1299 cells; however, co-treatment with SAHA significantly increased ATO-induced DNA damage. Moreover, SAHA enhanced acetylation of histone H3 and sensitized genomic DNA to DNase I digestion. Our results suggest that SAHA may cause chromatin relaxation and increase cellular susceptibility to ATO-induced DNA damage. Combined administration of SAHA and ATO may be an effective approach to the treatment of lung cancer. -- Highlights: Black-Right-Pointing-Pointer ATO and SAHA are therapeutic agents with different action modes. Black-Right-Pointing-Pointer Combination of ATO and SAHA synergistically inhibits tumor cell growth. Black-Right-Pointing-Pointer SAHA loosens chromatin structure resulting in increased sensitivity to DNase I. Black-Right-Pointing-Pointer ATO-induced DNA damage and apoptosis are enhanced by co-treatment with SAHA.

  16. Cardiomyogenic Differentiation of Human Dental Follicle-derived Stem Cells by Suberoylanilide Hydroxamic Acid and Their In Vivo Homing Property

    PubMed Central

    Sung, Iel-Yong; Son, Han-Na; Ullah, Imran; Bharti, Dinesh; Park, Ju-Mi; Cho, Yeong-Cheol; Byun, June-Ho; Kang, Young-Hoon; Sung, Su-Jin; Kim, Jong-Woo; Rho, Gyu-Jin; Park, Bong-Wook

    2016-01-01

    The purpose of the present study was to investigate the in vitro cardiomyogenic differentiation potential of human dental follicle-derived stem cells (DFCs) under the influence of suberoylanilide hydroxamic acid (SAHA), a member of the histone deacetylase inhibitor family, and analyze the in vivo homing capacity of induced cardiomyocytes (iCMs) when transplanted systemically. DFCs from extracted wisdom teeth showed mesenchymal stem cell (MSC) characteristics such as plate adherent growing, expression of MSC markers (CD44, CD90, and CD105), and mesenchymal lineage-specific differentiation potential. Adding SAHA to the culture medium induced the successful in vitro differentiation of DFCs into cardiomyocytes. These iCMs expressed cardiomyogenic markers, including alpha-smooth muscle actin (α-SMA), cardiac muscle troponin T (TNNT2), Desmin, and cardiac muscle alpha actin (ACTC1), at both the mRNA and protein level. For the assessment of homing capacity, PKH26 labeled iCMs were intraperitoneally injected (1×106 cells in 100 µL of PBS) into the experimental mice, and the ratios of PKH26 positive cells to the total number of injected cells, in multiple organs were determined. The calculated homing ratios, 14 days after systemic cell transplantation, were 5.6 ± 1.0%, 3.6 ± 1.1%, and 11.6 ± 2.7% in heart, liver, and kidney respectively. There was no difference in the serum levels of interleukin-2 and interleukin-10 at 14 days after transplantation, between the experimental (iCM injected) and control (no injection or PBS injection) groups. These results demonstrate that DFCs can be an excellent source for cardiomyocyte differentiation and regeneration. Moreover, the iCMs can be delivered into heart muscle via systemic administration without eliciting inflammatory or immune response. This can serve as the pilot study for further investigations into the in vitro cardiomyogenic differentiation potential of DFCs under the influence of SAHA and the in vivo homing capacity

  17. Suberoylanilide Hydroxamic Acid Treatment Reveals Crosstalks among Proteome, Ubiquitylome and Acetylome in Non-Small Cell Lung Cancer A549 Cell Line

    PubMed Central

    Wu, Quan; Cheng, Zhongyi; Zhu, Jun; Xu, Weiqing; Peng, Xiaojun; Chen, Chuangbin; Li, Wenting; Wang, Fengsong; Cao, Lejie; Yi, Xingling; Wu, Zhiwei; Li, Jing; Fan, Pingsheng

    2015-01-01

    Suberoylanilide hydroxamic acid (SAHA) is a well-known histone deacetylase (HDAC) inhibitor and has been used as practical therapy for breast cancer and non-small cell lung cancer (NSCLC). It is previously demonstrated that SAHA treatment could extensively change the profile of acetylome and proteome in cancer cells. However, little is known about the impact of SAHA on other protein modifications and the crosstalks among different modifications and proteome, hindering the deep understanding of SAHA-mediated cancer therapy. In this work, by using SILAC technique, antibody-based affinity enrichment and high-resolution LC-MS/MS analysis, we investigated quantitative proteome, acetylome and ubiquitylome as well as crosstalks among the three datasets in A549 cells toward SAHA treatment. In total, 2968 proteins, 1099 acetylation sites and 1012 ubiquitination sites were quantified in response to SAHA treatment, respectively. With the aid of intensive bioinformatics, we revealed that the proteome and ubiquitylome were negatively related upon SAHA treatment. Moreover, the impact of SAHA on acetylome resulted in 258 up-regulated and 99 down-regulated acetylation sites at the threshold of 1.5 folds. Finally, we identified 55 common sites with both acetylation and ubiquitination, among which ubiquitination level in 43 sites (78.2%) was positive related to acetylation level. PMID:25825284

  18. Suberoylanilide hydroxamic acid treatment reveals crosstalks among proteome, ubiquitylome and acetylome in non-small cell lung cancer A549 cell line.

    PubMed

    Wu, Quan; Cheng, Zhongyi; Zhu, Jun; Xu, Weiqing; Peng, Xiaojun; Chen, Chuangbin; Li, Wenting; Wang, Fengsong; Cao, Lejie; Yi, Xingling; Wu, Zhiwei; Li, Jing; Fan, Pingsheng

    2015-03-31

    Suberoylanilide hydroxamic acid (SAHA) is a well-known histone deacetylase (HDAC) inhibitor and has been used as practical therapy for breast cancer and non-small cell lung cancer (NSCLC). It is previously demonstrated that SAHA treatment could extensively change the profile of acetylome and proteome in cancer cells. However, little is known about the impact of SAHA on other protein modifications and the crosstalks among different modifications and proteome, hindering the deep understanding of SAHA-mediated cancer therapy. In this work, by using SILAC technique, antibody-based affinity enrichment and high-resolution LC-MS/MS analysis, we investigated quantitative proteome, acetylome and ubiquitylome as well as crosstalks among the three datasets in A549 cells toward SAHA treatment. In total, 2968 proteins, 1099 acetylation sites and 1012 ubiquitination sites were quantified in response to SAHA treatment, respectively. With the aid of intensive bioinformatics, we revealed that the proteome and ubiquitylome were negatively related upon SAHA treatment. Moreover, the impact of SAHA on acetylome resulted in 258 up-regulated and 99 down-regulated acetylation sites at the threshold of 1.5 folds. Finally, we identified 55 common sites with both acetylation and ubiquitination, among which ubiquitination level in 43 sites (78.2%) was positive related to acetylation level.

  19. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    SciTech Connect

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-09-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  20. The Effects of Molecular Hydrogen and Suberoylanilide Hydroxamic Acid on Paraquat-Induced Production of Reactive Oxygen Species and TNF-α in Macrophages.

    PubMed

    Li, Jiaoyang; Wu, Xizi; Chen, Yao; Zeng, Renqing; Zhao, Yangzi; Chang, Panpan; Wang, Danna; Zhao, Qianwen; Deng, Yunlei; Li, Yongqing; Alam, Hasan B; Chong, Wei

    2016-12-01

    The aim of this study is to investigate the effects of molecular hydrogen (H2) and suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on paraquat (PQ)-stimulated production of reactive oxygen species (ROS) and tumor necrosis factor alpha (TNF-α) in macrophages. First, the PQ optimal concentration was determined in RAW264.7 macrophage by treating serum-starved cells with PQ at 0, 0.001, 0.01, 0.1, 1, and 10 mM. We evaluated at 1, 2 and 8 h (1) cell viability (by means of trypan blue exclusion method), (2) intracellular ROS levels (with a fluorescent DCFH-DA probe), and (3) TNF-α level in the culture media (determined by enzyme-linked immunosorbent assay, ELISA). Subsequently, mouse RAW267.4 macrophages were treated with PQ in combination with SAHA and/or H2 for 8 h. PQ exerted a significant stimulatory but nontoxic effect on RAW267.4 macrophages at 0.1 mM. This PQ concentration was used in the subsequent experiments. H2 and H2 combined with SAHA evoked a greater reduction in PQ-induced ROS production than SAHA alone, especially at 2 and 8 h. At 1 and 2 h, treatments involving H2 caused a greater decrease in PQ-induced production of TNF-α than the corresponding treatments without H2. However, at 8 h, treatment with SAHA evoked more pronounced effects on TNF-α than treatment without SAHA. H2 decreases PQ-induced ROS production and attenuates early PQ-induced TNF-α production whereas SAHA reduces the late phase of the PQ-induced TNF-α production in macrophages. The effects are enhanced by the combination of H2 and SAHA.

  1. Pretreatment with anti-oxidants sensitizes oxidatively stressed human cancer cells to growth inhibitory effect of suberoylanilide hydroxamic acid (SAHA)

    PubMed Central

    Mahlum, Amy; Mehraein-Ghomi, Farideh; Kegel, Stacy J.; Guo, Song; Peters, Noel R.; Wilding, George

    2013-01-01

    Purpose Most prostate, colon and breast cancer cells are resistant to growth inhibitory effects of suberoylanilide hydroxamic acid (SAHA). We have examined whether the high oxidative stress in these cells causes a loss of SAHA activity and if so, whether pretreatment with an anti-oxidant can sensitize these cells to SAHA. Methods A DNA-Hoechst dye fluorescence measured cell growth and dichlorfluorescein-diacetate (DCF-DA) dye fluorescence measured reactive oxygen species (ROS). Growth inhibitory and ROS-generating activities of SAHA in androgen-treated or untreated LNCaP cells and PC-3 prostate cancer cells, HT-29 and HCT-115 colon cancer cells, MDA-MB231 breast cancer cells and A549 and NCI-H460 lung cancer cells with or without pretreatment with an anti-oxidant Vitamin E was determined. SAHA activity against LNCaP cells treated with another anti-oxidant N-acetyl cysteine (NAC) was also determined. Liquid chromatography–mass spectrometry (LC–MS) was used to determine intracellular SAHA level. Results SAHA treatment markedly inhibits LNCaP cell growth, when the cells are at a low ROS level. SAHA is, however, inactive against the same cell line, when the cells are at a high ROS level. A significant decrease in SAHA level was observed in LNCaP cells with high ROS after 24-and 72-h treatment when compared to cells with low ROS. Vitamin E pretreatment that reduces cellular ROS, synergistically sensitizes oxidatively stressed LNCaP, PC-3, HT-29, HCT-115 and MDA-MB231 cells, but not the A-549 and NCI-H460 cells with low ROS to SAHA. NAC treatment also sensitized androgen-treated LNCaP cells to the growth inhibitory effects of SAHA. Conclusion Response to SAHA could be improved by combining anti-oxidants such as Vitamin E with SAHA for the treatment of oxidatively stressed human malignancies that are otherwise resistant to SAHA. PMID:20512578

  2. Suberoylanilide hydroxamic acid (SAHA) and cladribine synergistically induce apoptosis in NK-LGL leukaemia.

    PubMed

    Sun, Xiaoshen; Hasanali, Zainul S; Chen, Allshine; Zhang, Dianzheng; Liu, Xin; Wang, Hong-Gang; Feith, David J; Loughran, Thomas P; Xu, Kailin

    2015-02-01

    Natural killer (NK) large granular lymphocyte (LGL) leukaemia features a clonal proliferation of CD3(-) NK cells that can be classified into either aggressive or chronic categories. The NKL cell line, derived from an aggressive Asian NK cell leukaemia, and patient samples from chronic NK-LGL leukaemia were used in our study to probe for synergistic efficacy of the epigenetic drugs vorinostat (SAHA) and cladribine in this disease. We demonstrate that histone deacetylases (HDACs) are over-expressed in both aggressive and chronic NK leukaemia. Administration of the HDAC inhibitor SAHA reduces class I and II HDAC expression and enhances histone acetylation in leukaemic NK cells. In vitro combination treatment with SAHA and cladribine dose-dependently exerts synergistic cytotoxic and apoptotic effects on leukaemic NK cells. Expression profiling of apoptotic regulatory genes suggests that both compounds led to caspase-dependent apoptosis through activation of intrinsic mitochondrial and extrinsic death receptor pathways. Collectively, these data show that combined epigenetic therapy, using HDAC and DNA methyltransferase inhibitors, may be a promising therapeutic approach for NK-LGL leukaemia. © 2014 John Wiley & Sons Ltd.

  3. Dose-Responsive Gene Expression in Suberoylanilide Hydroxamic Acid (SAHA) Treated Resting CD4+ T Cells

    PubMed Central

    Reardon, Brian; Beliakova-Bethell, Nadejda; Spina, Celsa A.; Singhania, Akul; Margolis, David M.; Richman, Douglas R.; Woelk, Christopher H.

    2015-01-01

    Design Persistent latently infected CD4+ T cells represent a major obstacle to HIV eradication. Histone deacetylase inhibitors (HDACis) are a proposed activation therapy. However, off-target effects on expression in host immune cells are poorly understood. We hypothesized that HDACi-modulated genes would be best identified with dose-response analysis. Methods Resting primary CD4+ T cells were treated with 0.34, 1, 3, or 10 μM of the HDACi, SAHA, for 24 hours and subjected to microarray gene expression analysis. Genes with dose-correlated expression were filtered to identify a subset with consistent up or downregulation at each SAHA dose. Histone modifications were characterized in 6 SAHA dose-responsive genes by chromatin immunoprecipitation (ChIP-RT-qPCR). Results A large number of genes were shown to be up (N=657) or downregulated (N=725) by SAHA in a dose-responsive manner (FDR p-value < 0.05, fold change ≥ |2|). Several genes (CTNNAL1, DPEP2, H1F0, IRGM, PHF15, and SELL) are potential in vivo biomarkers of SAHA activity. SAHA dose-responsive genes included transcription factors, HIV restriction factors, histone methyltransferases, and host proteins that interact with HIV. Pathway analysis suggested net downregulation of T cell activation with increasing SAHA dose. Histone acetylation was not correlated with host gene expression, but plausible alternative mechanisms for SAHA-modulated gene expression were identified. Conclusions Numerous genes in CD4+ T cells are modulated by SAHA in a dose-responsive manner, including genes that may negatively influence HIV activation from latency. Our study suggests that SAHA influences gene expression through a confluence of several mechanisms, including histone modification, and altered expression and activity of transcription factors. PMID:26258524

  4. High turbulence liquid chromatography online extraction and tandem mass spectrometry for the simultaneous determination of suberoylanilide hydroxamic acid and its two metabolites in human serum.

    PubMed

    Du, Lihong; Musson, Donald G; Wang, Amy Qiu

    2005-01-01

    A reliable and sensitive method incorporating high turbulence liquid chromatography (HTLC) online extraction with tandem mass spectrometry (MS/MS), for simultaneous determination of suberoylanilide hydroxamic acid (SAHA) and its two metabolites, SAHA-glucuronide (M1) and 4-anilino-4-oxobutanoic acid (M2), in human serum, has been developed to support clinical studies. The HTLC technology significantly reduces the time required for sample clean-up since sample extraction and analysis are performed online. Clinical samples, internal standards (IS) and buffer are transferred into 96-well plates using a robotic liquid handling system. A 20 microL aliquot of prepared sample is directly injected into the HTLC/LC-MS/MS system where the matrix is rapidly washed away to waste and the analytes are retained on the narrow-bore extraction column (0.5 x 50 mm), using an aqueous mobile phase at 1.5 mL/min. Analytes are then eluted from the extraction column and transferred to the analytical column using a gradient mobile phase prior to detection by MS/MS. Interference with determination of SAHA from in-source dissociation of M1 is eliminated by the chromatographic separation. The resolution of SAHA and M1 did not change for more than 1500 serum sample injections by applying an acid wash (15% acetic acid) on the extraction column. The linear calibration ranges for SAHA, M1, and M2 are 2-500, 5-2000, and 10-2000 ng/mL, respectively. Assay intraday validation was conducted using five calibration curves prepared in five lots of human control serum. The precision expressed as relative standard deviation (RSD) is less than 6.8% and accuracy is 94.6-102.9% of nominal values for all three analytes. Assay specificity, freeze/thaw stability, storage stability, and matrix effects were also assessed. Copyright (c) 2005 John Wiley & Sons, Ltd.

  5. Defining the role of histone deacetylases in the inhibition of mammary carcinogenesis by dietary energy restriction (DER): effects of suberoylanilide hydroxamic acid (SAHA) and DER in a rat model.

    PubMed

    Zhu, Zongjian; Jiang, Weiqin; McGinley, John N; Thompson, Henry J

    2013-04-01

    Dietary energy restriction (DER) inhibits experimentally induced mammary cancer, an effect accompanied by elevated levels of silent information regulator 2 (SIRT1), a class III histone deacetylase (HDAC). However, the effect of DER on targets of other classes of HDACs has not been reported, a highly relevant issue given evidence that HDAC induction favors the development of cancer and tumor growth. Experiments were carried out to determine whether suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor with broad activity, would affect the anti-cancer activity of DER. Female Sprague Dawley rats (n = 30/group) were injected with 1-methyl-1-nitrosourea (50 mg/kg) at 21 days of age and 7 days thereafter were randomized to groups fed: (i) control diet (AIN-93G), (ii) 0.1% SAHA (w/w), (iii) 40% DER, or (iv) 0.1% SAHA + 40% DER. An additional group was fed 0.1% SAHA + 40%DER for 5 weeks and released to control diet for 3 weeks. DER significantly reduced mammary cancer incidence, multiplicity, and cancer burden and prolonged cancer latency (P < 0.01). Cancer inhibition was maintained in SAHA + DER, despite evidence that histone (H2A(Lys9), H2B(Lys5), and H4(Lys5/8/12/16), but not H3(Lys9); P < 0.001) and non-histone protein deacetylation (p53(Lys373) and p53(Lys382); P < 0.001) induced by DER was reversed by SAHA. This indicates that the inhibition of DER of cancer is not dependent on HDAC induction. After releasing rats from DER + SAHA, cancer multiplicity remained lower than control (P < 0.05), consistent with apoptosis-mediated cell deletion. These findings support further investigation of the hypothesis that HDAC induction by DER blunts its anti-carcinogenic impact.

  6. Effect of suberoylanilide hydroxamic acid (SAHA) administration on the residual virus pool in a model of combination antiretroviral therapy-mediated suppression in SIVmac239-infected indian rhesus macaques.

    PubMed

    Del Prete, Gregory Q; Shoemaker, Rebecca; Oswald, Kelli; Lara, Abigail; Trubey, Charles M; Fast, Randy; Schneider, Douglas K; Kiser, Rebecca; Coalter, Vicky; Wiles, Adam; Wiles, Rodney; Freemire, Brandi; Keele, Brandon F; Estes, Jacob D; Quiñones, Octavio A; Smedley, Jeremy; Macallister, Rhonda; Sanchez, Rosa I; Wai, John S; Tan, Christopher M; Alvord, W Gregory; Hazuda, Daria J; Piatak, Michael; Lifson, Jeffrey D

    2014-11-01

    Nonhuman primate models are needed for evaluations of proposed strategies targeting residual virus that persists in HIV-1-infected individuals receiving suppressive combination antiretroviral therapy (cART). However, relevant nonhuman primate (NHP) models of cART-mediated suppression have proven challenging to develop. We used a novel three-class, six-drug cART regimen to achieve durable 4.0- to 5.5-log reductions in plasma viremia levels and declines in cell-associated viral RNA and DNA in blood and tissues of simian immunodeficiency virus SIVmac239-infected Indian-origin rhesus macaques, then evaluated the impact of treatment with the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA; Vorinostat) on the residual virus pool. Ex vivo SAHA treatment of CD4(+) T cells obtained from cART-suppressed animals increased histone acetylation and viral RNA levels in culture supernatants. cART-suppressed animals each received 84 total doses of oral SAHA. We observed SAHA dose-dependent increases in acetylated histones with evidence for sustained modulation as well as refractoriness following prolonged administration. In vivo virologic activity was demonstrated based on the ratio of viral RNA to viral DNA in peripheral blood mononuclear cells, a presumptive measure of viral transcription, which significantly increased in SAHA-treated animals. However, residual virus was readily detected at the end of treatment, suggesting that SAHA alone may be insufficient for viral eradication in the setting of suppressive cART. The effects observed were similar to emerging data for repeat-dose SAHA treatment of HIV-infected individuals on cART, demonstrating the feasibility, utility, and relevance of NHP models of cART-mediated suppression for in vivo assessments of AIDS virus functional cure/eradication approaches.

  7. Mixed effects of suberoylanilide hydroxamic acid (SAHA) on the host transcriptome and proteome and their implications for HIV reactivation from latency.

    PubMed

    White, Cory H; Johnston, Harvey E; Moesker, Bastiaan; Manousopoulou, Antigoni; Margolis, David M; Richman, Douglas D; Spina, Celsa A; Garbis, Spiros D; Woelk, Christopher H; Beliakova-Bethell, Nadejda

    2015-11-01

    Suberoylanilide hydroxamic acid (SAHA) has been assessed in clinical trials as part of a "shock and kill" strategy to cure HIV-infected patients. While it was effective at inducing expression of HIV RNA ("shock"), treatment with SAHA did not result in a reduction of reservoir size ("kill"). We therefore utilized a combined analysis of effects of SAHA on the host transcriptome and proteome to dissect its mechanisms of action that may explain its limited success in "shock and kill" strategies. CD4+ T cells from HIV seronegative donors were treated with 1μM SAHA or its solvent dimethyl sulfoxide (DMSO) for 24h. Protein expression and post-translational modifications were measured with iTRAQ proteomics using ultra high-precision two-dimensional liquid chromatography-tandem mass spectrometry. Gene expression was assessed by Illumina microarrays. Using limma package in the R computing environment, we identified 185 proteins, 18 phosphorylated forms, 4 acetylated forms and 2982 genes, whose expression was modulated by SAHA. A protein interaction network integrating these 4 data types identified the HIV transcriptional repressor HMGA1 to be upregulated by SAHA at the transcript, protein and acetylated protein levels. Further functional category assessment of proteins and genes modulated by SAHA identified gene ontology terms related to NFκB signaling, protein folding and autophagy, which are all relevant to HIV reactivation. In summary, SAHA modulated numerous host cell transcripts, proteins and post-translational modifications of proteins, which would be expected to have very mixed effects on the induction of HIV-specific transcription and protein function. Proteome profiling highlighted a number of potential counter-regulatory effects of SAHA with respect to viral induction, which transcriptome profiling alone would not have identified. These observations could lead to a more informed selection and design of other HDACi with a more refined targeting profile, and

  8. Response of preclinical medulloblastoma models to combination therapy with 13-cis retinoic acid and suberoylanilide hydroxamic acid (SAHA).

    PubMed

    Spiller, Susan E; Ditzler, Sally H; Pullar, Barbara J; Olson, James M

    2008-04-01

    Current medulloblastoma therapy, surgery, radiation, and chemotherapy, is unacceptably toxic. However, 13-cis retinoic acid (RA) and SAHA, a histone deacetylase inhibitor, have each been shown to induce apoptosis in medulloblastoma cultures and mouse models. Both drugs cross the blood brain barrier, have been given safely to children, and achieve brain concentrations that are at or near therapeutic levels. Retinoic acid acts by transcriptionally activating bone morphogenetic protein-2 (BMP-2) and SAHA facilitates transcriptional activity through chromatin accessibility. We tested the hypothesis that these drugs additively induce BMP-2 transcription and apoptosis. RA + SAHA induction of BMP-2 transcription and apoptosis in medulloblastoma cultures was evaluated. Subsequently the response of mouse medulloblastomas to these two agents in the presence and absence of cisplatin was evaluated. BMP-2 transcription multiplied 3-fold with addition of RA to culture, and 7-fold with both agents. The IC50 of SAHA was reduced by 40% when low dose RA was added. Interestingly, a p38 MAP kinase inhibitor that partially blocks RA-induced apoptosis did not inhibit the activity of RA + SAHA. Flank D283 tumors in athymic mice had slower growth in the RA + SAHA arm than single drug or control arms. Intracranial tumors in ND2:SmoA1 mice treated with RA + SAHA + cisplatin showed a 4-fold increase in apoptosis over controls, and a 2-fold increase over animals receiving only SAHA or RA + SAHA. RA + SAHA additively induce BMP-2 transcription and medulloblastoma apoptosis. The combination may act through a p38 MAPK independent mechanism. Efficacy increased with cisplatin, which has implications for clinical trial design.

  9. Pyridone Methylsulfone Hydroxamate LpxC Inhibitors for the Treatment of Serious Gram-Negative Infections

    SciTech Connect

    Montgomery, Justin I.; Brown, Matthew F.; Reilly, Usa; Price, Loren M.; Abramite, Joseph A.; Arcari, Joel; Barham, Rose; Che, Ye; Chen, Jinshan Michael; Chung, Seung Won; Collantes, Elizabeth M.; Desbonnet, Charlene; Doroski, Matthew; Doty, Jonathan; Engtrakul, Juntyma J.; Harris, Thomas M.; Huband, Michael; Knafels, John D.; Leach, Karen L.; Liu, Shenping; Marfat, Anthony; McAllister, Laura; McElroy, Eric; Menard, Carol A.; Mitton-Fry, Mark; Mullins, Lisa; Noe, Mark C.; O’Donnell, John; Oliver, Robert; Penzien, Joseph; Plummer, Mark; Shanmugasundaram, Veerabahu; Thoma, Christy; Tomaras, Andrew P.; Uccello, Daniel P.; Vaz, Alfin; Wishka, Donn G.

    2012-11-09

    The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.

  10. 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.

  11. Why Hydroxamates May Not Be the Best Histone Deacetylase Inhibitors--What Some May Have Forgotten or Would Rather Forget?

    PubMed

    Shen, Sida; Kozikowski, Alan P

    2016-01-05

    Hydroxamate-based histone deacetylase inhibitors (HDACIs) have been approved as therapeutic agents by the US Food and Drug Administration for use in oncology applications. While the potential utility of such HDACIs in other areas of medicinal chemistry is tremendous, there are significant concerns that "pan-HDAC inhibitors" may be too broadly acting and/or toxic for clinical use beyond oncology. In addition to the isozyme selectivity challenge, the potential mutagenicity of hydroxamate-containing HDAC inhibitors represents a major hindrance in their application to other therapeutic areas. Herein we report on the mutagenicity of known hydroxamates, discuss the mechanisms responsible for their genotoxicity, and review some of the current alternatives to hydroxamates. We conclude that the hydroxamate group, while providing high-potency HDACIs, is not necessarily the best zinc-binding group for HDACI drug discovery.

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

    SciTech Connect

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

    2016-11-04

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

  13. Cytotoxic effects of Jay Amin hydroxamic acid (JAHA), a ferrocene-based class I histone deacetylase inhibitor, on triple-negative MDA-MB231 breast cancer cells.

    PubMed

    Librizzi, Mariangela; Longo, Alessandra; Chiarelli, Roberto; Amin, Jahanghir; Spencer, John; Luparello, Claudio

    2012-11-19

    The histone deacetylase inhibitors (HDACis) are a class of chemically heterogeneous anticancer agents of which suberoylanilide hydroxamic acid (SAHA) is a prototypical member. SAHA derivatives may be obtained by three-dimensional manipulation of SAHA aryl cap, such as the incorporation of a ferrocene unit like that present in Jay Amin hydroxamic acid (JAHA) and homo-JAHA [ Spencer , et al. ( 2011 ) ACS Med. Chem. Lett. 2 , 358 - 362 ]. These metal-based SAHA analogues have been tested for their cytotoxic activity toward triple-negative MDA-MB231 breast cancer cells. The results obtained indicate that of the two compounds tested, only JAHA was prominently active on breast cancer cells with an IC(50) of 8.45 μM at 72 h of treatment. Biological assays showed that exposure of MDA-MB231 cells to the HDACi resulted in cell cycle perturbation with an alteration of S phase entry and a delay at G(2)/M transition and in an early reactive oxygen species production followed by mitochondrial membrane potential (MMP) dissipation and autophagy inhibition. No annexin binding was observed after short- (5 h) and longer (24 and 48 h) term incubation with JAHA, thereby excluding the promotion of apoptosis by the HDACi. Although caution must be exercised in extrapolation of in vitro results to the in vivo situation for which research on animals and human trials are needed, nevertheless JAHA treatment possesses the potential for its development as an agent for prevention and/or therapy of "aggressive" breast carcinoma, thus prompting us to get more insight into the molecular basis of its antibreast cancer activity.

  14. 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.

  15. 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

  16. Translational Phase I Trial of Vorinostat (Suberoylanilide Hydroxamic Acid) Combined with Cytarabine and Etoposide in Patients with Relapsed, Refractory, or High-Risk Acute Myeloid Leukemia

    PubMed Central

    Gojo, Ivana; Tan, Ming; Fang, Hong-Bin; Sadowska, Mariola; Lapidus, Rena; Baer, Maria R.; Carrier, France; Beumer, Jan H.; Anyang, Bean N.; Srivastava, Rakesh K.; Espinoza-Delgado, Igor; Ross, Douglas D.

    2015-01-01

    Purpose To determine the maximum-tolerated dose (MTD) of the histone deacetylase inhibitor vorinostat combined with fixed doses of cytarabine (ara-C or cytosine arabinoside) and etoposide in patients with poor-risk or advanced acute leukemia, to obtain preliminary efficacy data, describe pharmacokinetics, and in vivo pharmacodynamic effects of vorinostat in leukemia blasts. Experimental Design In this open-label phase I study, vorinostat was given orally on days one to seven at three escalating dose levels: 200 mg twice a day, 200 mg three times a day, and 300 mg twice a day. On days 11 to 14, etoposide (100 mg/m2) and cytarabine (1 or 2 g/m2 twice a day if ≥65 or <65 years old, respectively) were given. The study used a standard 3+3 dose escalation design. Results Eighteen of 21 patients with acute myelogenous leukemia (AML) treated on study completed planned therapy. Dose-limiting toxicities [hyperbilirubinemia/septic death (1) and anorexia/fatigue (1)] were encountered at the 200 mg three times a day level; thus, the MTD was established to be vorinostat 200 mg twice a day. Of 21 patients enrolled, seven attained a complete remission (CR) or CR with incomplete platelet recovery, including six of 13 patients treated at the MTD. The median remission duration was seven months. No differences in percentage S-phase cells or multidrug resistance transporter (MDR1 or BCRP) expression or function were observed in vivo in leukemia blasts upon vorinostat treatment. Conclusions Vorinostat 200 mg twice a day can be given safely for seven days before treatment with cytarabine and etoposide. The relatively high CR rate seen at the MTD in this poor-risk group of patients with AML warrants further studies to confirm these findings. PMID:23403629

  17. Molecular docking studies of a group of hydroxamate inhibitors with gelatinase-A by molecular dynamics

    NASA Astrophysics Data System (ADS)

    Hou, Tingjun; Zhang, Wei; Xu, Xiaojie

    2002-01-01

    We have performed docking and molecular dynamics simulations of hydroxamates complexed with human gelatinase-A (MMP-2) to gain insight into the structural and energetic preferences of these inhibitors. The study was conducted on a selected set of eleven compounds with variation in structure and activity. Molecular dynamics simulations were performed at 300 K for 100 ps with equilibration for 50 ps. The structural analyses of the trajectories indicate that the coordinate bond interactions, the hydrogen bond interactions, the van der Waals interactions as well as the hydrophobic interactions between ligand and receptor are responsible simultaneously for the preference of inhibition and potency. The ligand hydroxamate group is coordinated to the catalytic zinc ion and form stable hydrogen bonds with the carbonyl oxygen of Gly 162. The P1' group makes extensive van der Waals and hydrophobic contacts with the nonpolar side chains of several residues in the S1' subsite, including Leu 197, Val 198, Leu 218 and Tyr 223. Moreover, four to eight hydrogen bonds between hydroxamates and MMP-2 are formed to stabilize the inhibitors in the active site. Compared with the P2' and P3' groups, the P1' groups of inhibitors are oriented regularly, which is produced by the restrain of the S1' subsite. From the relationship between the length of the nonpolar P1' group and the biological activity, we confirm that MMP-2 has a pocket-like S1' subsite, not a channel-like S1' subsite proposed by Kiyama (Kiyama, R. et al., J. Med. Chem. 42 (1999), 1723). The energetic analyses show that the experimental binding free energies can be well correlated with the interactions between the inhibitors and their environments, which could be used as a simple score function to evaluate the binding affinities for other similar hydroxamates. The validity of the force field parameters and the MD simulations can be fully testified by the satisfactory agreements between the experimental structure

  18. Targeted Polypharmacology: Discovery of a Highly Potent Non-Hydroxamate Dual Matrix Metalloproteinase (MMP)-10/-13 Inhibitor.

    PubMed

    Senn, Nicole; Ott, Michael; Lanz, Jan; Riedl, Rainer

    2017-09-27

    Matrix metalloproteinases (MMPs) play a key role in many diseases like cancer, atherosclerosis or arthritis. Interest in MMP inhibition has been revitalized very recently as the knowledge on the underlying network of biological pathways is steadily growing. Based on this new insight into the relevance of MMP-10 and MMP-13 within the MMP network and the ban of hydroxamate inhibitors from clinical development, the discovery of non-hydroxamate multi-target drugs against specific MMPs is of foremost interest. Here, we disclose the discovery of a very potent and selective non-hydroxamate MMP-10/-13 inhibitor. The high potency (IC50 of 31 nM [MMP-10] and 5 nM [MMP-13]) and selectivity over MMP-1, -2, -3, -7, -8, -9, -12 and -14 enable this compound to decipher disease causing MMP networks and to generate new treatment options through targeted polypharmacology.

  19. Reexamining hydroxamate inhibitors of botulinum neurotoxin serotype A: Extending towards the β-exosite

    PubMed Central

    Caglič, Dejan; Čapek, Petr; Zhang, Yan; Godbole, Sujata; Reitz, Allen B.

    2012-01-01

    Botulinum neurotoxins (BoNTs) are the most toxic proteins known to man, exposure to which results in flaccid paralysis. Given their extreme potency, these proteins have become studied as possible weapons of bioterrorism; however, effective treatments that function after intoxication have not progressed to the clinic. Here, we have reexamined one of the most effective inhibitors, 2,4-dichlorocinnamyl hydroxamate, in the context of the known plasticity of the BoNT/A light chain metalloprotease. Our studies have shown that modifications of this compound are tolerated and result in improved inhibitors, with the best compound having an IC50 of 0.23 μM. Given the inconsistency of structure-activity relationship trends observed across similar compounds, this data argues for caution in extrapolating across structural series. PMID:22542019

  20. 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.

  1. CoMFA and CoMSIA 3D-QSAR analysis on hydroxamic acid derivatives as urease inhibitors.

    PubMed

    Ul-Haq, Zaheer-; Wadood, Abdul; Uddin, Reaz

    2009-02-01

    Urease (EC 3.5.1.5) serves as a virulence factor in pathogens that are responsible for the development of many diseases in humans and animals. Urease allows soil microorganisms to use urea as a source of nitrogen and aid in the rapid break down of urea-based fertilizers resulting in phytopathicity. It has been well established that hydroxamic acids are the potent inhibitors of urease activity. The 3D-QSAR studies on thirty five hydroxamic acid derivatives as known urease inhibitors were performed by Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) methods to determine the factors required for the activity of these compounds. The CoMFA model produced statistically significant results with cross-validated (q(2)) 0.532 and conventional (r(2)) correlation coefficients 0.969.The model indicated that the steric field (70.0%) has greater influence on hydroxamic acid inhibitors than the electrostatic field (30.0%). Furthermore, five different fields: steric, electrostatic, hydrophobic, H-bond donor and H-bond acceptor assumed to generate the CoMSIA model, which gave q(2) 0.665 and r(2) 0.976.This model showed that steric (43.0%), electrostatic (26.4%) and hydrophobic (20.3%) properties played a major role in urease inhibition. The analysis of CoMFA and CoMSIA contour maps provided insight into the possible modification of the hydroxamic acid derivatives for improved activity.

  2. Benzothiazole-containing hydroxamic acids as histone deacetylase inhibitors and antitumor agents.

    PubMed

    Oanh, Dao Thi Kim; Hai, Hoang Van; Park, Sang Ho; Kim, Hyun-Jung; Han, Byung-Woo; Kim, Hyung-Sook; Hong, Jin-Tae; Han, Sang-Bae; Hue, Van Thi My; Nam, Nguyen-Hai

    2011-12-15

    Data from clinical studies indicate that inhibitors of Class I and Class II histone deacetylase (HDAC) enzymes show great promise for the treatment of cancer. Zolinza (SAHA, Zolinza) was recently approved by the FDA for the treatment of the cutaneous manifestations of cutaneous T-cell lymphoma. As a part of our ongoing effort to identify novel small molecules to target these important enzymes, we have prepared two series of benzothiazole-containing analogues of SAHA. It was found that several compounds with 6C-bridge linking benzothiazole moiety and hydroxamic functional groups showed good inhibition against HDAC3 and 4 at as low as 1 μg/ml and exhibited potent cytotoxicity against five cancer cell lines with average IC(50) values of as low as 0.81 μg/ml, almost equipotent to SAHA.

  3. New hydroxamate inhibitors of neurotensin-degrading enzymes. Synthesis and enzyme active-site recognition.

    PubMed

    Bourdel, E; Doulut, S; Jarretou, G; Labbe-Jullie, C; Fehrentz, J A; Doumbia, O; Kitabgi, P; Martinez, J

    1996-08-01

    Selective and mixed inhibitors of the three zinc metallopeptidases that degrade neurotensin (NT), e.g. endopeptidase 24-16 (EC 3.4.24.16), endopeptidase 24-11 (EC 3.4.24.11 or neutral endopeptidase, NEP) and endopeptidase 24-15 (EC 3.4.24.15), and leucine-aminopeptidase (type IV-S), that degrades the NT-related peptides, Neuromedin N (NN), are of great interest. On the structural basis of compound JMV 390-1 (N-[3-[(hydroxyamino)carbonyl]-1-oxo-2(R)-benzylpropyl]-L- isoleucyl-L-leucine), which was a full inhibitor of the major NT degrading enzymes, several hydroxamate inhibitors corresponding to the general formula HONHCO-CH2-CH(CH2-C6H5)CO-X-Y-OH (with X-Y = dipeptide) have been synthesized. Compound 7a (X-Y = Ile-Ala) was nearly 40-times more potent in inhibiting EC 24-16 than NEP and more than 800-times more potent than EC 24-15, with an IC50 (12 nM) almost equivalent to that of compound JMV 390-1. Therefore, this compound is an interesting selective inhibitor of EC 24-16, and should be an interesting probe to explore the physiological involvement of EC 24-16 in the metabolism of neurotensin.

  4. Antimalarial activity of phenylthiazolyl-bearing hydroxamate-based histone deacetylase inhibitors.

    PubMed

    Dow, Geoffrey S; Chen, Yufeng; Andrews, Katherine T; Caridha, Diana; Gerena, Lucia; Gettayacamin, Montip; Johnson, Jacob; Li, Qigui; Melendez, Victor; Obaldia, Nicanor; Tran, Thanh N; Kozikowski, Alan P

    2008-10-01

    The antimalarial activity and pharmacology of a series of phenylthiazolyl-bearing hydroxamate-based histone deacetylase inhibitors (HDACIs) was evaluated. In in vitro growth inhibition assays approximately 50 analogs were evaluated against four drug resistant strains of Plasmodium falciparum. The range of 50% inhibitory concentrations (IC(50)s) was 0.0005 to >1 microM. Five analogs exhibited IC(50)s of <3 nM, and three of these exhibited selectivity indices of >600. The most potent compound, WR301801 (YC-2-88) was shown to cause hyperacetylation of P. falciparum histones, which is a marker for HDAC inhibition in eukaryotic cells. The compound also inhibited malarial and mammalian HDAC activity in functional assays at low nanomolar concentrations. WR301801 did not exhibit cures in P. berghei-infected mice at oral doses as high as 640 mg/kg/day for 3 days or in P. falciparum-infected Aotus lemurinus lemurinus monkeys at oral doses of 32 mg/kg/day for 3 days, despite high relative bioavailability. The failure of monotherapy in mice may be due to a short half-life, since the compound was rapidly hydrolyzed to an inactive acid metabolite by loss of its hydroxamate group in vitro (half-life of 11 min in mouse microsomes) and in vivo (half-life in mice of 3.5 h after a single oral dose of 50 mg/kg). However, WR301801 exhibited cures in P. berghei-infected mice when combined at doses of 52 mg/kg/day orally with subcurative doses of chloroquine. Next-generation HDACIs with greater metabolic stability than WR301801 may be useful as antimalarials if combined appropriately with conventional antimalarial drugs.

  5. Effects of hydroxamate metalloendoprotease inhibitors on botulinum neurotoxin A poisoned mouse neuromuscular junctions

    PubMed Central

    Thyagarajan, Baskaran; Potian, Joseph G.; Garcia, Carmen C.; Hognason, Kormakur; Čapková, Kateřina; Moe, Scott T.; Jacobson, Alan R.; Janda, Kim D.; McArdle, Joseph J.

    2010-01-01

    Summary Currently the only therapy for botulinum neurotoxin A (BoNT/A) poisoning is antitoxin. Antidotes that are effective after BoNT/A has entered the motor nerve terminals would dramatically benefit BoNT/A therapy. Inhibition of proteolytic activity of BoNT/A light chain by metalloendoprotease inhibitors (MEIs) is under development. We tested the effects of MEIs on in vitro as well as in vivo BoNT/A poisoned mouse nerve muscle preparations (NMPs). The Ki for inhibition of BoNT/A metalloendoprotease was 0.40 and 0.36 μM, respectively, for 2, 4 – dichlorocinnamic acid hydroxamate (DCH) and its methyl derivative, ABS 130. Acute treatment of nerve muscle preparations with 10 pM BoNT/A inhibited nerve evoked muscle twitches, reduced mean quantal content, and induced failures of endplate currents (EPCs). Bath application of 10 μM DCH or 5 μM ABS 130 reduced failures, increased the quantal content of EPCs, and partially restored muscle twitches after a delay of 40 to 90 min. The restorative effects of DCH and ABS 130, as well as 3,4 diaminopyridine (DAP) on twitch tension were greater at 22 °C compared to 37 °C. Unlike DAP, neither DCH nor ABS 130 increased Ca2+ levels in cholinergic Neuro 2a cells. Injection of MEIs into mouse hind limbs before or after BoNT/A injection neither prevented the toe spread reflex inhibition nor improved muscle functions. We suggest that hydroxamate MEIs partially restore neurotransmission of acutely BoNT/A poisoned nerve muscle preparations in vitro in a temperature dependent manner without increasing the Ca2+ levels within motor nerve endings. PMID:20211192

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

    PubMed

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

    2017-08-01

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

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

    PubMed

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

    2016-02-25

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

  8. Promotion of Germination Using Hydroxamic Acid Inhibitors of 9-cis-Epoxycarotenoid Dioxygenase

    PubMed Central

    Awan, Sajjad Z.; Chandler, Jake O.; Harrison, Peter J.; Sergeant, Martin J.; Bugg, Timothy D. H.; Thompson, Andrew J.

    2017-01-01

    Abscisic acid (ABA) inhibits seed germination and the regulation of ABA biosynthesis has a role in maintenance of seed dormancy. The key rate-limiting step in ABA biosynthesis is catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED). Two hydroxamic acid inhibitors of carotenoid cleavage dioxygenase (CCD), D4 and D7, previously found to inhibit CCD and NCED in vitro, are shown to have the novel property of decreasing mean germination time of tomato (Solanum lycopersicum L.) seeds constitutively overexpressing LeNCED1. Post-germination, D4 exhibited no negative effects on tomato seedling growth in terms of height, dry weight, and fresh weight. Tobacco (Nicotiana tabacum L.) seeds containing a tetracycline-inducible LeNCED1 transgene were used to show that germination could be negatively and positively controlled through the chemical induction of gene expression and the chemical inhibition of the NCED protein: application of tetracycline increased mean germination time and delayed hypocotyl emergence in a similar manner to that observed when exogenous ABA was applied and this was reversed by D4 when NCED expression was induced at intermediate levels. D4 also improved germination in lettuce (Lactuca sativa L.) seeds under thermoinhibitory temperatures and in tomato seeds imbibed in high osmolarity solutions of polyethylene glycol. D4 reduced ABA and dihydrophaseic acid accumulation in tomato seeds overexpressing LeNCED1 and reduced ABA accumulation in wild type tomato seeds imbibed on polyethylene glycol. The evidence supports a mode of action of D4 through NCED inhibition, and this molecule provides a lead compound for the design of NCED inhibitors with greater specificity and potency. PMID:28373878

  9. Intrinsic apoptotic and thioredoxin pathways in human prostate cancer cell response to histone deacetylase inhibitor

    PubMed Central

    Xu, Weisheng; Ngo, Lang; Perez, Gisela; Dokmanovic, Milos; Marks, Paul A.

    2006-01-01

    There is a great need to develop better mechanism-based therapies for prostate cancer. In this investigation, we studied four human prostate cancer cell lines, LNCaP, DU145, LAPC4, and PC3, which differ in response to the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (vorinostat), a new anticancer drug. Examining the role of intrinsic mitochondrial caspase-dependent apoptosis and caspase-independent, reactive oxygen species (ROS) facilitated cell death, has provided an understanding of mechanisms that may determine the varied response to the histone deacetylase inhibitor. We found striking differences among these cancer cells in constitutive expression and response to suberoylanilide hydroxamic acid in levels of antiapoptotic and proapoptotic proteins, mitochondria membrane integrity, activation of caspases, ROS accumulation, and expression of thioredoxin, the major scavenger of ROS. Identifying these differences can have predictive value in assessing therapeutic response and identifying targets to enhance therapeutic efficacy. PMID:17030815

  10. Functional differences in epigenetic modulators-superiority of mercaptoacetamide-based histone deacetylase inhibitors relative to hydroxamates in cortical neuron neuroprotection studies.

    PubMed

    Kozikowski, Alan P; Chen, Yufeng; Gaysin, Arsen; Chen, Bin; D'Annibale, Melissa A; Suto, Carla M; Langley, Brett C

    2007-06-28

    We compare the ability of two structurally different classes of epigenetic modulators, namely, histone deacetylase (HDAC) inhibitors containing either a hydroxamate or a mercaptoacetamide as the zinc binding group, to protect cortical neurons in culture from oxidative stress-induced death. This study reveals that some of the mercaptoacetamide-based HDAC inhibitors are fully protective, whereas the hydroxamates show toxicity at higher concentrations. Our present results appear to be consistent with the possibility that the mercaptoacetamide-based HDAC inhibitors interact with a different subset of the HDAC isozymes [less activity at HDAC1 and 2 correlates with less inhibitor toxicity], or alternatively, are interacting selectively with only the cytoplasmic HDACs that are crucial for protection from oxidative stress.

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

    PubMed

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

    2016-12-15

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

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

    PubMed Central

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

    2016-01-01

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

  13. Histone deacetylase inhibitors as a tool to up-regulate new fungal biosynthetic products: isolation of EGM-556, a cyclodepsipeptide, from Microascus sp.

    PubMed

    Vervoort, Hélène C; Drašković, Marija; Crews, Phillip

    2011-02-04

    The histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) was used to turn on the biosynthesis of EGM-556, a new cyclodepsipeptide of hybrid biosynthetic origin, isolated from the Floridian marine sediment-derived fungus Microascus sp. The absolute configurations of three chiral centers were determined by Marfey's derivatization. EGM-556 represents one of the few examples in which silent biosynthetic genes, encoding a new secondary metabolite, were activated by means of epigenetic manipulation of the fungal metabolome.

  14. Tumor Selective Cytotoxic Action of a Thiomorpholin Hydroxamate Inhibitor (TMI-1) in Breast Cancer

    PubMed Central

    Mezil, Lynda; Berruyer-Pouyet, Carole; Cabaud, Olivier; Josselin, Emmanuelle; Combes, Sébastien; Brunel, Jean-Michel; Viens, Patrice; Collette, Yves; Birnbaum, Daniel; Lopez, Marc

    2012-01-01

    Background Targeted therapies, associated with standard chemotherapies, have improved breast cancer care. However, primary and acquired resistances are frequently observed and the development of new concepts is needed. High-throughput approaches to identify new active and safe molecules with or without an “a priori” are currently developed. Also, repositioning already-approved drugs in cancer therapy is of growing interest. The thiomorpholine hydroxamate compound TMI-1 has been previously designed to inhibit metalloproteinase activity for the treatment of rheumatoid arthritis. We present here the repositioning of TMI-1 drug in breast cancer. Methodology/Principal Findings We tested the effect of TMI-1 on luminal, basal and ERBB2-overexpressing breast tumor cell lines and on MMTV-ERBB2/neu tumor evolution. We measured the effects on i) cell survival, ii) cell cycle, iii) extrinsic and intrinsic apoptotic pathways, iv) association with doxorubicin, docetaxel and lapatinib, v) cancer stem cells compartment. In contrast with conventional cytotoxic drugs, TMI-1 was highly selective for tumor cells and cancer stem cells at submicromolar range. All non-malignant cells tested were resistant even at high concentration. TMI-1 was active on triple negative (TN) and ERBB2-overexpressing breast tumor cell lines, and was also highly efficient on human and murine “primary” ERBB2-overexpressing cells. Treatment of transgenic MMTV-ERBB2/neu mice with 100 mg/kg/day TMI-1 alone induced tumor apoptosis, inhibiting mammary gland tumor occurrence and development. No adverse effects were noticed during the treatment. This compound had a strong synergistic effect in association with docetaxel, doxorubicin and lapatinib. We showed that TMI-1 mediates its selective effects by caspase-dependent apoptosis. TMI-1 was efficient in 34/40 tumor cell lines of various origins (ED50: 0.6 µM to 12.5 µM). Conclusions/Significance This is the first demonstration of the tumor selective

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

    PubMed

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

    2017-09-06

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

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

    PubMed

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

    2017-03-10

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

  17. Synthesis of new glycyrrhetinic acid derived ring A azepanone, 29-urea and 29-hydroxamic acid derivatives as selective 11β-hydroxysteroid dehydrogenase 2 inhibitors.

    PubMed

    Gaware, Rawindra; Khunt, Rupesh; Czollner, Laszlo; Stanetty, Christian; Da Cunha, Thierry; Kratschmar, Denise V; Odermatt, Alex; Kosma, Paul; Jordis, Ulrich; Classen-Houben, Dirk

    2011-03-15

    Glycyrrhetinic acid, the metabolite of the natural product glycyrrhizin, is a well known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and type 2. Whereas inhibition of 11β-HSD1 is currently under consideration for treatment of metabolic diseases, such as obesity and diabetes, 11β-HSD2 inhibitors may find therapeutic applications in chronic inflammatory diseases and certain forms of cancer. Recently, we published a series of hydroxamic acid derivatives of glycyrrhetinic acid showing high selectivity for 11β-HSD2. The most potent and selective compound is active against human 11β-HSD2 in the low nanomolar range with a 350-fold selectivity over human 11β-HSD1. Starting from the lead compounds glycyrrhetinic acid and the hydroxamic acid derivatives, novel triterpene type derivatives were synthesized and analyzed for their biological activity against overexpressed human 11β-HSD1 and 11β-HSD2 in cell lysates. Here we describe novel 29-urea- and 29-hydroxamic acid derivatives of glycyrrhetinic acid as well as derivatives with the Beckman rearrangement of the 3-oxime to a seven-membered ring, and the rearrangement of the C-ring from 11-keto-12-ene to 12-keto-9(11)-ene. The combination of modifications on different positions led to compounds comprising further improved selective inhibition of 11β-HSD2 in the lower nanomolar range with up to 3600-fold selectivity.

  18. Subchronic Toxicities of HZ1006, a Hydroxamate-Based Histone Deacetylase Inhibitor, in Beagle Dogs and Sprague-Dawley Rats

    PubMed Central

    Zhang, Xiaofang; Zhang, Xiaodong; Yuan, Bojun; Ren, Lijun; Zhang, Tianbao; Lu, Guocai

    2016-01-01

    Histone deacetylase inhibitors (HDACIs), such as vorinostat and panobinostat, have been shown to have active effects on many hematologic malignancies, including multiple myeloma and cutaneous T-cell lymphoma. Hydroxamate-based (Hb) HDACIs have very good toxicity profiles and are currently being tested in phases I and II clinical trials with promising results in selected neoplasms, such as bladder carcinoma. One of the Hb-HDACIs, HZ1006, has been demonstrated to be a promising drug for clinical use. The aim of our study was to determine the possible target of toxicity and to identify a non-toxic dose of HZ1006 for clinical use. In our studies, the repeated dosage toxicity of HZ1006 in Beagle dogs and Sprague Dawley (SD) rats was identified. Dogs and rats received HZ1006 orally (0–80 and 0–120 mg/kg/day, respectively) on a continuous daily dosing agenda for 28 days following a 14-day dosage-free period. HZ1006’s NOAEL (No Observed Adverse Effect Level) by daily oral administration for dogs and rats was 5 mg/kg and 60 mg/kg, respectively, and the minimum toxic dose was 20 and 120 mg/kg, respectively. All the side effects indicated that the digestive tract, the male reproductive tract, the respiratory tract and the hematological systems might be HZ1006 toxic targets in humans. HZ1006 could be a good candidate or a safe succedaneum to other existing HDACIs for the treatment of some solid tumor and hematologic malignancies. PMID:27916918

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

    PubMed

    Qvortrup, Katrine; Nielsen, Thomas E

    2016-03-24

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

  20. 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.

  1. New benzothiazole/thiazole-containing hydroxamic acids as potent histone deacetylase inhibitors and antitumor agents.

    PubMed

    Tung, Truong Thanh; Oanh, Dao Thi Kim; Dung, Phan Thi Phuong; Hue, Van Thi My; Park, Sang Ho; Han, Byung Woo; Kim, Youngsoo; Hong, Jin-Tae; Han, Sang-Bae; Nam, Nguyen-Hai

    2013-12-01

    Results from clinical studies have demonstrated that inhibitors of histone deacetylase (HDAC) enzymes possess promise for the treatment of several types of cancer. Zolinza(®) (widely known as SAHA) has been approved by the FDA for the treatment of T-cell lymphoma. As a continuity of our ongoing research to find novel small molecules to target these important enzymes, we synthesized a series of benzothiazole-containing analogues of SAHA and found several compounds with very potent anticancer cytotoxicity. In this study, three more compounds of this type, including N(1)-(6-chlorobenzo[d]thiazol-2-yl)-N(8)-hydroxyoctanediamide (3a), N(1)-[6-(trifluoromethyl)benzo[d]thiazol-2-yl]-N(8)-hydroxyoctanediamide (3b) and N(1)-(thiazol-2-yl)-N(8)-hydroxyoctanediamide (6) were synthesized and evaluated for HDAC inhibition and cytotoxic activities. All three compounds showed very potent HDAC inhibitory effects. Docking revealed that both two compounds 3a, 3b showed higher affinities towards HDAC(8) compared to SAHA. In vitro, compound 3a exhibited cytotoxicity equipotent to SAHA against five human cancer cell lines. In term of in vivo activity, compound 3a demonstrated equivalent efficacy to SAHA in mouse xenograft model.

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

    PubMed

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

    2008-03-01

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

  3. BW A4C and other hydroxamic acids are potent inhibitors of linoleic acid 8R-dioxygenase of the fungus Gaeumannomyces graminis.

    PubMed

    Brodowsky, I D; Hamberg, M; Oliw, E H

    1994-03-11

    Linoleic acid is converted to 8R-hydroperoxylinoleic acid by the soluble 8R-dioxygenase of the fungus Gaeumannomyces graminis. Effects of different lipoxygenase inhibitors on the 8R-dioxygenase were evaluated. Three hydroxamic acid derivatives were investigated. BW A4C (N-(3-phenoxycinnamyl)acetohydroxamic acid) was the most potent with an IC50 of 0.2 microM, followed by zileuton (3-10 microM) and linoleate-hydroxamic acid (0.02 mM). Two other lipoxygenase inhibitors, nordihydroguaiaretic acid and eicosatetraynoic acid, were less potent (IC50 0.09 and 0.15 mM, respectively). The 8R-dioxygenase was also strongly inhibited by commonly used buffer additives, dithiothreitol, beta-mercaptoethanol and phenylmethanesulfonyl fluoride. G. graminis also contains a hydroperoxide isomerase, which converts 8R-hydroperoxylinoleic acid to 7S,8S-dihydroxylinoleic acid. Ammonium sulphate precipitation and gel filtration indicated that the dioxygenase and the hydroperoxide isomerase activities could be separated.

  4. Design and synthesis of a tetrahydroisoquinoline-based hydroxamate derivative (ZYJ-34v), an oral active histone deacetylase inhibitor with potent antitumor activity.

    PubMed

    Zhang, Yingjie; Liu, Chunxi; Chou, C James; Wang, Xuejian; Jia, Yuping; Xu, Wenfang

    2013-08-01

    In our previous study, we developed a novel series of tetrahydroisoquinoline-based hydroxamic acid derivatives as histone deacetylase inhibitors (Bioorg Med Chem, 2010, 18, 1761-1772; J Med Chem, 2011, 54, 2823-2838), among which, compound ZYJ-34c (1) was identified and validated as the most potent one with marked in vitro and in vivo antitumor potency (J Med Chem, 2011, 54, 5532-5539.). Herein, further modification in 1 afforded another oral active analog ZYJ-34v (2) with simplified structure and lower molecular weight. Biological evaluation of compound 2 showed efficacious inhibition against histone deacetylase 1, 2, 3, and 6, which was confirmed by Western blot analysis results. Most importantly, compound 2 exhibited similar even more potent in vitro and in vivo antitumor activities relative to the approved histone deacetylase inhibitor SAHA.

  5. Hydroxamic acid – A novel molecule for anticancer therapy

    PubMed Central

    Pal, Dilipkumar; Saha, Supriyo

    2012-01-01

    Hydroxamic acid is a potent moiety not only in the field of cancer therapy but also as a mutagenic agent. Among the various derivatives of hydroxamic acid, SAHA (Suberoylanilide Hydroxamic Acid) is considered as a potent anticancer agent. Scientists from the different corner synthesized different hydroxamic acid moieties with some straight chain oxazole, thiadiazole, biphenyl moieties in the terminal position. Acetylation and deacetylation of histones of the core proteins of nucleosomes in chromatin play an important role in the regulation of gene expression. The level of acetylation of histones is established and maintained by two classes of enzymes, histone acetyltransferase and histone deacetylases, which have been identified as transcriptional coactivators and transcriptional corepressors, respectively. There is increasing evidence that aberrant histone acetylation has been linked to various malignant diseases. Great efforts are currently underway for the design of more potent and less toxic candidates for the treatment of cancer. In recent years, hydroxamic acid derivatives have attracted increasing attention for their potential as highly efficacious in combating various etiological factors associated with cancer. Our main intention to draw an attention is that this single functional moiety has not only fit in the receptor but also create a diversified activity. PMID:22837956

  6. Syntheses and Discovery of a Novel Class of Cinnamic Hydroxamates as Histone Deacetylase Inhibitors by Multimodality Molecular Imaging in Living Subjects

    PubMed Central

    Chan, C.T.; Qi, J.; Smith, W.; Paranol, R.; Mazitschek, R.; West, N.; Reeves, R.; Chiosis, G.; Schreiber, S.L.; Bradner, J.E.; Paulmurugan, R.; Gambhir, S.S.

    2015-01-01

    Histone deacetylases (HDAC) that regulate gene expression are being explored as cancer therapeutic targets. In this study, we focused on HDAC6 based on its ability to inhibit cancerous Hsp90 chaperone activities by disrupting Hsp90/p23 interactions. To identify novel HDAC6 inhibitors, we used a dual-luciferase reporter system in cell culture and living mice by bioluminescence imaging (BLI). On the basis of existing knowledge, a library of hydrazone compounds was generated for screening by coupling cinnamic hydroxamates with aldehydes and ketones. Potency and selectivity were determined by in vitro HDAC profiling assays, with further evaluation to inhibit Hsp90(α/β)/p23 interactions by BLI. In this manner, we identified compound 1A12 as a dose-dependent inhibitor of Hsp90(α/β)/p23 interactions, UKE-1 myeloid cell proliferation, p21waf1 upregulation, and acetylated histone H3 levels. 1A12 was efficacious in tumor xenografts expressing Hsp90(α)/p23 reporters relative to carrier control–treated mice as determined by BLI. Small animal 18F-FDG PET/CT imaging on the same cohort showed that 1A12 also inhibited glucose metabolism relative to control subjects. Ex vivo analyses of tumor lysates showed that 1A12 administration upregulated acetylated-H3 by approximately 3.5-fold. Taken together, our results describe the discovery and initial preclinical validation of a novel selective HDAC inhibitor. PMID:25320008

  7. Syntheses and discovery of a novel class of cinnamic hydroxamates as histone deacetylase inhibitors by multimodality molecular imaging in living subjects.

    PubMed

    Chan, C T; Qi, J; Smith, W; Paranol, R; Mazitschek, R; West, N; Reeves, R; Chiosis, G; Schreiber, S L; Bradner, J E; Paulmurugan, R; Gambhir, S S

    2014-12-15

    Histone deacetylases (HDAC) that regulate gene expression are being explored as cancer therapeutic targets. In this study, we focused on HDAC6 based on its ability to inhibit cancerous Hsp90 chaperone activities by disrupting Hsp90/p23 interactions. To identify novel HDAC6 inhibitors, we used a dual-luciferase reporter system in cell culture and living mice by bioluminescence imaging (BLI). On the basis of existing knowledge, a library of hydrazone compounds was generated for screening by coupling cinnamic hydroxamates with aldehydes and ketones. Potency and selectivity were determined by in vitro HDAC profiling assays, with further evaluation to inhibit Hsp90(α/β)/p23 interactions by BLI. In this manner, we identified compound 1A12 as a dose-dependent inhibitor of Hsp90(α/β)/p23 interactions, UKE-1 myeloid cell proliferation, p21(waf1) upregulation, and acetylated histone H3 levels. 1A12 was efficacious in tumor xenografts expressing Hsp90(α)/p23 reporters relative to carrier control-treated mice as determined by BLI. Small animal (18)F-FDG PET/CT imaging on the same cohort showed that 1A12 also inhibited glucose metabolism relative to control subjects. Ex vivo analyses of tumor lysates showed that 1A12 administration upregulated acetylated-H3 by approximately 3.5-fold. Taken together, our results describe the discovery and initial preclinical validation of a novel selective HDAC inhibitor. ©2014 American Association for Cancer Research.

  8. Synthesis of novel 3-amino and 29-hydroxamic acid derivatives of glycyrrhetinic acid as selective 11β-hydroxysteroid dehydrogenase 2 inhibitors.

    PubMed

    Stanetty, Christian; Czollner, Laszlo; Koller, Iris; Shah, Priti; Gaware, Rawindra; Cunha, Thierry Da; Odermatt, Alex; Jordis, Ulrich; Kosma, Paul; Classen-Houben, Dirk

    2010-11-01

    Glycyrrhetinic acid, the metabolite of the natural product glycyrrhizin, is a well known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and type 2. Whereas inhibition of 11β-HSD1 is currently under consideration for treatment of metabolic diseases, such as obesity and diabetes, 11β-HSD2 inhibitors may find therapeutic applications in chronic inflammatory diseases and certain forms of cancer. So far, no selective 11β-HSD2 inhibitor has been developed and neither animal studies nor clinical trials have been reported based on 11β-HSD2 inhibition. Starting from the lead compound glycyrrhetinic acid, novel triterpene type derivatives were synthesized and analyzed for their biological activity against overexpressed human 11β-HSD1 and 11β-HSD2 in cell lysates. Several hydroxamic acid derivatives showed high selectivity for 11β-HSD2. The most potent and selective compound is active against human 11β-HSD2 in the low nanomolar range with a 350-fold selectivity over human 11β-HSD1.

  9. 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

  10. Predicting Novel Antitumor Agents: 3D-Pharmacophore Mapping of β-N-biaryl Ether Sulfonamide-Based Hydroxamates as Potentially MMP-2 Inhibitors.

    PubMed

    Medeiros Turra, Kely; Pineda Rivelli, Diogo; Berlanga de Moraes Barros, Silvia; Fernanda Mesquita Pasqualoto, Kerly

    2014-09-01

    Matrix metalloproteinases (MMP) are a group of enzymes related to extracelular matrix remodeling. Some types of MMP are overexpressed by malignant tumors, mainly the MMP-2 subtype, and have been associated to cancer invasiveness and metastasis. A receptor-independent (RI) 4D-QSAR formalism was applied, herein, to a set of forty β-N-biaryl ether sulfonamide hydroxamates, previously reported as potent MMP-2 inhibitors, in order to map 3D-pharmacophore models and predict novel antitumor agents. The best RI 4D-QSAR model was statistically significant (N=30, r(2) =0.93, q(2) =0.88, five occupancy descriptors (GCOD), LSE=0.04, LOF=0.11, outliers=0), robust and not obtained by chance. The external predictability was 75 % (test set; N=8). A different orientation (binding mode) in the MMP-2 catalytic site was suggested regarding the most hydrophobic portion (R1 ) of the compounds' structure. Compounds were predicted and their inhibitory activity against MMP-2 was calculated by using the optimum RI 4D-QSAR model. The findings have provided interesting information to drive the designing and synthesis of novel potentially MMP-2 inhibitors against melanoma invasion.

  11. 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.

  12. Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex.

    PubMed

    O'Brien, E C; Farkas, E; Gil, M J; Fitzgerald, D; Castineras, A; Nolan, K B

    2000-04-01

    Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) > copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions.

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

    PubMed Central

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

    2010-01-01

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

  14. Hydroxamate-induced spectral perturbations of cobalt Aeromonas aminopeptidase.

    PubMed

    Wilkes, S H; Prescott, J M

    1987-06-25

    The absorption spectrum of cobalt(II)-substituted Aeromonas aminopeptidase is markedly perturbed by the presence of equimolar concentrations of D-amino acid hydroxamates and acyl hydroxamates that have previously been shown to be powerful inhibitors of this enzyme (Wilkes, S. H., and Prescott, J. M. (1983) J. Biol. Chem. 258, 13517-13521). D-Valine hydroxamate produces the most distinctive perturbation, splitting the characteristic 527 nm absorption peak of the cobalt enzyme to form peaks at 564, 520, and 487 nm with molar extinction values of 126, 98, and 67 M-1 cm-1, respectively. A qualitatively similar perturbation, albeit with lower extinction values, results from the addition of D-leucine hydroxamate, whereas D-alanine hydroxamate perturbs the spectrum, but does not evoke the peak at 564 nm. In contrast, hydroxamates of L-valine and L-leucine in concentrations equi-molar to that of the enzyme produce only faint indications of change in the spectrum, but the hydroxamates of several other L-amino acids perturb the spectrum essentially independently of the identity of the side chain and in a qualitatively different manner from that of D-valine hydroxamate and D-leucine hydroxamate. At the high enzyme:substrate ratios used in the spectral experiments, L-leucine hydroxamate and L-valine hydroxamate proved to be rapidly hydrolyzed, hence their inability to perturb the spectrum of the cobalt-substituted enzyme during the time course of a spectral experiment. Values of kcat for L-amino acid hydroxamates, all of which are good reversible inhibitors of the hydrolysis of L-leucine-p-nitroanilide by Aeromonas aminopeptidase, were found to range from 0.01 min-1 to 5.6 min-1 for the native enzyme and from 0.27 min-1 to 108 min-1 for the cobalt-substituted enzyme; their km values toward the cobalt aminopeptidase range from 1.2 X 10(-7) M to 1.9 X 10(-5) M. The mutual exclusivity of binding for hydroxamate inhibitors and 1-butaneboronic acid, previously shown by kinetics

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

    PubMed Central

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

    2013-01-01

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

  16. Hydroxamic Acids in Asymmetric Synthesis

    PubMed Central

    Li, Zhi; Yamamoto, Hisashi

    2012-01-01

    Metal-catalyzed stereoselective reactions are a central theme in organic chemistry research. In these reactions, the stereoselection is achieved predominantly by introducing chiral ligands at the metal catalyst’s center. For decades, researchers have sought better chiral ligands for asymmetric catalysis and have made great progress. Nevertheless, to achieve optimal stereoselectivity and to catalyze new reactions, new chiral ligands are needed. Due to their high metal affinity, hydroxamic acids play major roles across a broad spectrum of fields from biochemistry to metal extraction. Dr. K. Barry Sharpless first revealed their potential as chiral ligands for asymmetric synthesis in 1977: He published the chiral vanadium-hydroxamic-acid-catalyzed, enantioselective epoxidation of allylic alcohols before his discovery of Sharpless Asymmetric Epoxidation, which uses titanium-tartrate complex as the chiral reagent. However, researchers have reported few highly enantioselective reactions using metal-hydroxamic acid as catalysts since then. This Account summarizes our research on metal-catalyzed asymmetric epoxidation using hydroxamic acids as chiral ligands. We designed and synthesized a series of new hydroxamic acids, most notably the C2-symmetric bis-hydroxamic acid (BHA) family. V-BHA-catalyzed epoxidation of allylic and homoallylic alcohols achieved higher activity and stereoselectivity than Sharpless Asymmetric Epoxidation in many cases. Changing the metal species led to a series of unprecedented asymmetric epoxidation reactions, such as (i) single olefins and sulfides with Mo-BHA, (ii) homoallylic and bishomoallylic alcohols with Zr- and Hf-BHA, and (iii) N-alkenyl sulfonamides and N-sulfonyl imines with Hf-BHA. These reactions produce uniquely functionalized chiral epoxides with good yields and enantioselectivities. PMID:23157425

  17. An appraisal of cinnamyl sulfonamide hydroxamate derivatives (HDAC inhibitors) for anti-cancer, anti-angiogenic and anti-metastatic activities in human cancer cells.

    PubMed

    Reddy, Neetinkumar D; Shoja, M H; Biswas, Subhankar; Nayak, Pawan G; Kumar, Nitesh; Rao, C Mallikarjuna

    2016-06-25

    Multiple genetic mutations along with unusual epigenetic modifications play a major role in cancer development. Histone deacetylase (HDAC) enzyme overexpression observed in the majority of cancers is responsible for tumor suppressor gene silencing and activation of proto-oncogenes to oncogenes. Cinnamic acid derivatives exhibit anti-cancer potential through HDAC enzyme inhibition. We have synthesized a few cinnamyl sulfonamide hydroxamate derivatives (NMJ-1, -2 and -3) by already published in-house procedures and their purity, and chemical characterization were performed by NMR, mass spectrometry and elemental analysis. The anti-cancer activities were also evaluated against colon cancer. The rationale for synthesis was based on bioisosterism concept. To take the work forward, these compounds were considered for in vitro anti-angiogenic and anti-metastatic activities in cancer cells. The effectiveness of these compounds was determined by SRB assay. The compounds showed cancer cell cytotoxicity (IC50 range of 5.7 ± 0.43 to 20.5 ± 1.9 μM). The mechanism of compound-induced cell death involves an intrinsic apoptosis pathway which was supported by the following: increase in apoptotic index, arrest in cell cycle at G2/M phase, increase in annexin V binding and induction of p21(Waf1/Cip1) expression in the treated cells. Further, their target modulating effect, measured as the expression of acetyl-H3 histone and acetyl α-tubulin was determined by Western blots. Hyper acetylation of H3 histone and α-tubulin were observed. Furthermore, increased expression of cleaved caspase-3, cleaved PARP, total Bad was estimated by ELISA. The anti-angiogenic effect was examined through cobalt (II) chloride (CoCl2)-induced HIF-1α expression, where the compounds reduced the expression of induced HIF-1α. In addition, their anti-metastatic ability was determined through phorbol-12-myristate-13-acetate (PMA)-induced expression of MMP-2 and -9 by Western blotting and gelatin

  18. Why Hydroxamates May Not Be the Best Histone Deacetylase Inhibitors—What Some May Have Forgotten or Would Rather Forget?

    PubMed Central

    Shen, Sida

    2016-01-01

    Hydroxamate-based histone deacetylase inhibitors (HDACIs) have been approved as therapeutic agents by the US Food and Drug Administration for use in oncology applications. While the potential utility of such HDACIs in other areas of medicinal chemistry is tremendous, there are significant concerns that “pan-HDAC inhibitors” may be too broadly acting and/or toxic for clinical use beyond oncology. In addition to the isozyme selectivity challenge, the potential mutagenicity of hydroxamate-containing HDAC inhibitors represents a major hindrance in their application to other therapeutic areas. Herein we report on the mutagenicity of known hydroxamates, discuss the mechanisms responsible for their genotoxicity, and review some of the current alternatives to hydroxamates. We conclude that the hydroxamate group, while providing high-potency HDACIs, is not necessarily the best zinc-binding group for HDACI drug discovery. PMID:26603496

  19. Anticancer activity of SAHA, a potent histone deacetylase inhibitor, in NCI-H460 human large-cell lung carcinoma cells in vitro and in vivo.

    PubMed

    Zhao, Yanxia; Yu, Dandan; Wu, Hongge; Liu, Hongli; Zhou, Hongxia; Gu, Runxia; Zhang, Ruiguang; Zhang, Sheng; Wu, Gang

    2014-02-01

    Suberoylanilide hydroxamic acid (SAHA), a potent pan-histone deacetylase (HDAC) inhibitor, has been clinically approved for the treatment of cutaneous T-cell lymphoma (CTCL). SAHA has also been shown to exert a variety of anticancer activities in many other types of tumors, however, few studies have been reported in large-cell lung carcinoma (LCC). Our study aimed to investigate the potential antitumor effects of SAHA on LCC cells. Here, we report that SAHA was able to inhibit the proliferation of the LCC cell line NCI-H460 in a dose- and time-dependent manner, induced cell apoptosis and G2/M cell cycle arrest, decreased AKT and ERK phosphorylation, inhibited the expression of pro-angiogenic factors (VEGF, HIF-1α) in vitro, and suppressed tumor progression in an NCI-H460 cell nude mouse xenograft model in vivo. These results indicate that SAHA can exert its strong antitumor effects in LCC patient.

  20. 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

  1. 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.

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

    PubMed Central

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

    2013-01-01

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

  3. Basic nuclear processes affected by histone acetyltransferases and histone deacetylase inhibitors.

    PubMed

    Legartová, Soňa; Stixová, Lenka; Strnad, Hynek; Kozubek, Stanislav; Martinet, Nadine; Dekker, Frank J; Franek, Michal; Bártová, Eva

    2013-08-01

    The optimal balance between histone acetylation and deacetylation is important for proper gene function. Therefore, we addressed how inhibitors of histone-modifying enzymes can modulate nuclear events, including replication, transcription, splicing and DNA repair. Changes in cell signaling pathways upon treatment with histone acetyltransferases and/or histone deacetylase inhibitors were studied by cDNA microarrays and western blots. We analyzed the effects of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and the histone acetylase inhibitor MG149. SAHA altered the expression of factors involved in DNA replication complexes, basal transcription and the spliceosome pathway. DNA repair-related genes, including Rad51, Rad54 and BRCA2, were significantly downregulated by SAHA. However, MG149 had no effect on the investigated nuclear processes, with the exception of the spliceosome network and Sestrins, involved in DNA repair. Based on our results, we propose that the studied epigenetic drugs have the distinct potential to affect specific cell signaling pathways depending on their respective molecular targets.

  4. 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.

  5. A Phase II Trial of Vorinostat (Suberoylanilide Hydroxamic Acid, -SAHA) in Metastatic Breast Cancer: A California Cancer Consortium Study

    PubMed Central

    Luu, Thehang H; Morgan, Robert J; Leong, Lucille; Lim, Dean; McNamara, Mark; Portnow, Jana; Frankel, Paul; Smith, David D.; Doroshow, James H.; Gandara, David R; Aparicio, Ana; Somlo, George

    2011-01-01

    Purpose The primary goal of this trial was to determine the response rate of single-agent vorinostat in patients with metastatic breast cancer. The secondary goals included assessment of time to progression, evaluation of toxicities, and overall survival. Experimental Design From June 2005 to March 2006, fourteen patients received vorinostat, 200 mg orally, twice daily for 14 days of each 21 day cycle. Response and progression were evaluated using RECIST criteria. Results The median age for all patients was 60.5 years (range: 37–88). Eight patients were ER and/or PR positive, four were Her-2 positive. Sites of metastatic disease included brain, liver, lungs, bones, pelvis, pleura, chest wall, and distant lymph nodes. Patients received a median of 1.5 prior (range: 0–2) chemotherapeutic regimens for metastatic disease. Fatigue, nausea, diarrhea, and lymphopenia were the most frequent clinically significant adverse effects. The median number of cycles delivered was two (range: 1–20). There were no complete or partial responses and the study was terminated after the first stage, however 4 patients were observed with stable disease with time to progression of 4,8,9 and 14 months. The median number of months that patients received treatment on this study was 1.7 (range: 0.5–14). Conclusion While not meeting the RECIST response criteria for adequate single-agent activity, the observed tolerable toxicities and the potential for clinical benefit in terms of stable disease suggest that further assessment of vorinostat as a part of combination therapy with either chemotherapeutic or targeted agents in metastatic breast might be undertaken. PMID:18981013

  6. Suberoylanilide Hydroxamic Acid in Treating Patients With Metastatic and/or Locally Advanced or Locally Recurrent Thyroid Cancer

    ClinicalTrials.gov

    2014-07-23

    Insular Thyroid Cancer; Recurrent Thyroid Cancer; Stage II Follicular Thyroid Cancer; Stage II Papillary Thyroid Cancer; Stage IV Follicular Thyroid Cancer; Stage IV Papillary Thyroid Cancer; Thyroid Gland Medullary Carcinoma

  7. The phosphatidylinositol 3-kinases (PI3K) inhibitor GS-1101 synergistically potentiates histone deacetylase inhibitor-induced proliferation inhibition and apoptosis through the inactivation of PI3K and extracellular signal-regulated kinase pathways.

    PubMed

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

    2013-10-01

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

  8. Rational combination treatment with histone deacetylase inhibitors and immunomodulatory drugs in multiple myeloma

    PubMed Central

    Hideshima, T; Cottini, F; Ohguchi, H; Jakubikova, J; Gorgun, G; Mimura, N; Tai, Y-T; Munshi, N C; Richardson, P G; Anderson, K C

    2015-01-01

    Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide (Len) and pomalidomide trigger anti-tumor activities in multiple myeloma (MM) by targetting cereblon and thereby impacting IZF1/3, c-Myc and IRF4. Histone deacetylase inhibitors (HDACi) also downregulate c-Myc. We therefore determined whether IMiDs with HDACi trigger significant MM cell growth inhibition by inhibiting or downregulating c-Myc. Combination treatment of Len with non-selective HDACi suberoylanilide hydroxamic acid or class-I HDAC-selective inhibitor MS275 induces synergic cytotoxicity, associated with downregulation of c-Myc. Unexpectedly, we observed that decreased levels of cereblon (CRBN), a primary target protein of IMiDs, was triggered by these agents. Indeed, sequential treatment of MM cells with MS275 followed by Len shows less efficacy than simultaneous treatment with this combination. Importantly ACY1215, an HDAC6 inhibitor with minimal effects on class-I HDACs, together with Len induces synergistic MM cytotoxicity without alteration of CRBN expression. Our results showed that only modest class-I HDAC inhibition is able to induce synergistic MM cytotoxicity in combination with Len. These studies may provide the framework for utilizing HDACi in combination with Len to both avoid CRBN downregulation and enhance anti-MM activities. PMID:25978432

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

    PubMed Central

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

    2013-01-01

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

  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. Rational combination treatment with histone deacetylase inhibitors and immunomodulatory drugs in multiple myeloma.

    PubMed

    Hideshima, T; Cottini, F; Ohguchi, H; Jakubikova, J; Gorgun, G; Mimura, N; Tai, Y-T; Munshi, N C; Richardson, P G; Anderson, K C

    2015-05-15

    Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide (Len) and pomalidomide trigger anti-tumor activities in multiple myeloma (MM) by targetting cereblon and thereby impacting IZF1/3, c-Myc and IRF4. Histone deacetylase inhibitors (HDACi) also downregulate c-Myc. We therefore determined whether IMiDs with HDACi trigger significant MM cell growth inhibition by inhibiting or downregulating c-Myc. Combination treatment of Len with non-selective HDACi suberoylanilide hydroxamic acid or class-I HDAC-selective inhibitor MS275 induces synergic cytotoxicity, associated with downregulation of c-Myc. Unexpectedly, we observed that decreased levels of cereblon (CRBN), a primary target protein of IMiDs, was triggered by these agents. Indeed, sequential treatment of MM cells with MS275 followed by Len shows less efficacy than simultaneous treatment with this combination. Importantly ACY1215, an HDAC6 inhibitor with minimal effects on class-I HDACs, together with Len induces synergistic MM cytotoxicity without alteration of CRBN expression. Our results showed that only modest class-I HDAC inhibition is able to induce synergistic MM cytotoxicity in combination with Len. These studies may provide the framework for utilizing HDACi in combination with Len to both avoid CRBN downregulation and enhance anti-MM activities.

  12. 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.

  13. Histone deacetylase inhibitors decrease Toll-like receptor-mediated activation of proinflammatory gene expression by impairing transcription factor recruitment

    PubMed Central

    Bode, Konrad A; Schroder, Kate; Hume, David A; Ravasi, Timothy; Heeg, Klaus; Sweet, Matthew J; Dalpke, Alexander H

    2007-01-01

    Post-translational modifications of histone proteins are major mechanisms that modify chromatin structure and regulate gene expression in eukaryotes. Activation of histone acetyltransferases or inhibition of histone deacetylases (HDACs) is generally believed to allow chromatin to assume a more open state, permitting transcriptional activity. We report here the surprising observation that treatment of murine dendritic cells with the HDAC inhibitors trichostatin A (TSA) or suberoylanilide hydroxamic acid (SAHA) in non-apoptotic concentrations strongly inhibited induction of both interleukin-12 protein p40 (IL-12p40) mRNA and protein upon stimulation of Toll-like receptors (TLRs). Moreover, TLR-mediated up-regulation of costimulatory molecules was also inhibited. Up-regulation of tumour necrosis factor-α mRNA and protein in response to TLR agonists was only affected upon prolonged exposure to HDAC inhibitors and regulation of IL-1β was not affected. Similar effects were apparent in murine and human macrophages. Regarding the mode of action, HDAC inhibition increased the acetylation status at the IL-12p40 locus. Nevertheless, IL-12p40 chromatin remodelling, binding of Rel-A and IRF1 to the IL-12p40 promoter and transcriptional activation were abrogated. In contrast, HDAC inhibitors had no effects on upstream nuclear factor-κB and mitogen-activated protein kinase activation. Thus HDACs positively regulate the expression of a subset of cytokine genes by enabling transcription factor recruitment. PMID:17635610

  14. A novel small molecule inhibitor of deubiquitylating enzyme USP14 and UCHL5 induces apoptosis in multiple myeloma and overcomes bortezomib resistance

    PubMed Central

    Tian, Ze; D’Arcy, Padraig; Wang, Xin; Ray, Arghya; Tai, Yu-Tzu; Hu, Yiguo; Carrasco, Ruben D.; Richardson, Paul; Linder, Stig; Anderson, Kenneth C.

    2014-01-01

    Proteasome inhibitors have demonstrated that targeting protein degradation is effective therapy in multiple myeloma (MM). Here we show that deubiquitylating enzymes (DUBs) USP14 and UCHL5 are more highly expressed in MM cells than in normal plasma cells. USP14 and UCHL5 short interfering RNA knockdown decreases MM cell viability. A novel 19S regulatory particle inhibitor b-AP15 selectively blocks deubiquitylating activity of USP14 and UCHL5 without inhibiting proteasome activity. b-AP15 decreases viability in MM cell lines and patient MM cells, inhibits proliferation of MM cells even in the presence of bone marrow stroma cells, and overcomes bortezomib resistance. Anti-MM activity of b-AP15 is associated with growth arrest via downregulation of CDC25C, CDC2, and cyclin B1 as well as induction of caspase-dependent apoptosis and activation of unfolded protein response. In vivo studies using distinct human MM xenograft models show that b-AP15 is well tolerated, inhibits tumor growth, and prolongs survival. Combining b-AP15 with suberoylanilide hydroxamic acid, lenalidomide, or dexamethasone induces synergistic anti-MM activity. Our preclinical data showing efficacy of b-AP15 in MM disease models validates targeting DUBs in the ubiquitin proteasomal cascade to overcome proteasome inhibitor resistance and provides the framework for clinical evaluation of USP14/UCHL5 inhibitors to improve patient outcome in MM. PMID:24319254

  15. Antitumor Action of a Novel Histone Deacetylase Inhibitor, YF479, in Breast Cancer1

    PubMed Central

    Zhang, Tao; Chen, Yihua; Li, Jingjie; Yang, Feifei; Wu, Haigang; Dai, Fujun; Hu, Meichun; Lu, Xiaoling; Peng, Yi; Liu, Mingyao; Zhao, Yongxiang; Yi, Zhengfang

    2014-01-01

    Accumulating evidence demonstrates important roles for histone deacetylase in tumorigenesis (HDACs), highlighting them as attractive targets for antitumor drug development. Histone deactylase inhibitors (HDACIs), which have shown favorable anti-tumor activity with low toxicity in clinical investigations, are a promising class of anticancer therapeutics. Here, we screened our compound library to explore small molecules that possess anti-HDAC activity and identified a novel HDACI, YF479. Suberoylanilide hydroxamic acid (SAHA), which was the first approved HDAC inhibitor for clinical treatment by the FDA, was as positive control in our experiments. We further demonstrated YF479 abated cell viability, suppressed colony formation and tumor cell motility in vitro. To investigate YF479 with superior pharmacodynamic properties, we developed spontaneous and experimental breast cancer animal models. Our results showed YF479 significantly inhibited breast tumor growth and metastasis in vivo. Further study indicated YF479 suppressed both early and end stages of metastatic progression. Subsequent adjuvant chemotherapy animal experiment revealed the elimination of local-regional recurrence (LRR) and distant metastasis by YF479. More important, YF479 remarkably prolonged the survival of tumor-bearing mice. Intriguingly, YF479 displayed more potent anti-tumor activity in vitro and in vivo compared with SAHA. Together, our results suggest that YF479, a novel HDACI, inhibits breast tumor growth, metastasis and recurrence. In light of these results, YF479 may be an effective therapeutic option in clinical trials for patients burdened by breast cancer. PMID:25220594

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

    PubMed

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

    2007-02-01

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

  17. A strategy for the solution-phase parallel synthesis of N-(pyrrolidinylmethyl)hydroxamic acids.

    PubMed

    Takayanagi, M; Flessner, T; Wong, C H

    2000-06-16

    Both five- and six-membered iminocyclitols have proven to be useful transition-state analogue inhibitors of glycosidases. They also mimic the transition-state sugar moiety of the nucleoside phosphate sugar in glycosyltransferase-catalyzed reactions. Described here is the development of a general strategy toward the parallel synthesis of a five-membered iminocyclitol linked to a hydroxamic acid group designed to mimic the transition state of GDP-fucose complexed with Mn(II) in fucosyltransferase reactions. The iminocyclitol 8 containing a protected hydroxylamine unit was prepared from D-mannitol. The hydroxamic acid moiety was introduced via the reaction of 8 with various acid chlorides. The strategy is generally applicable to the construction of libraries for identification of glycosyltransferase inhibitors.

  18. SAHA and S116836, a novel tyrosine kinase inhibitor, synergistically induce apoptosis in imatinib-resistant chronic myelogenous leukemia cells

    PubMed Central

    Bu, Qiangui; Cui, Lijing; Li, Juan; Du, Xin; Zou, Waiyi; Ding, Ke; Pan, Jingxuan

    2014-01-01

    Limited treatment options are available for chronic myelogenous leukemia (CML) patients who develop imatinib mesylate (IM) resistance. Here we proposed a novel combination regimen, a co-administration of S116836, a novel small molecule multi-targeted tyrosine kinase inhibitor that was synthesized by rational design, and histone deacetylases inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA), to overcome IM resistance in CML. S116836 at low concentrations used in the present study mildly downregulates auto-tyrosine phosphorylation of Bcr-Abl. SAHA, an FDA-approved HDACi drug, at 1 μM has modest anti-tumor activity in treating CML. However, we found a synergistic interaction between SAHA and S116836 in Bcr-Abl-positive CML cells that were sensitive or resistant to IM. Exposure of KBM5 and KBM5-T315I cells to minimal or non-toxic concentrations of SAHA and S116836 synergistically reduced cell viability and induced cell death. Co-treatment with SAHA and S116838 repressed the expressions of anti-apoptosis proteins, such as Mcl-1 and XIAP, but promoted Bim expression and mitochondrial damage. Of importance, treatment with both drugs significantly reduced cell viability of primary human CML cells, as compared with either agent alone. Taken together, our findings suggest that SAHA exerts synergistically with S116836 at a non-toxic concentration to promote apoptosis in the CML, including those resistant to imatinib or dasatinib. PMID:24759597

  19. Fate of labeled hydroxamates during iron transport from hydroxamate-ion chelates.

    PubMed

    Arceneaux, J E; Davis, W B; Downer, D N; Haydon, A H; Byers, B R

    1973-09-01

    The fate of the hydroxamic acid-iron transport cofactors during iron uptake from the (59)Fe(3+) chelates of the (3)H-labeled hydroxamates schizokinen and aerobactin was studied by assay of simultaneous incorporation of both (59)Fe(3+) and (3)H. In the schizokinen-producing organism Bacillus megaterium ATCC 19213 transport of (59)Fe(3+) from the (3)H-schizokinen-(59)Fe(3+) chelate at 37 C was accompanied by rapid uptake and release (within 2 min) of (3)H-schizokinen, although (3)H-schizokinen discharge was temperature-dependent and did not occur at 0 C. In the schizokinen-requiring strain B. megaterium SK11 similar release of (3)H-schizokinen occurred only at elevated concentrations of the double-labeled chelate; at lower chelate concentrations, (3)H-schizokinen remained cell-associated. Temperature-dependent uptake of deferri (iron-free) (3)H-schizokinen to levels equivalent to those incorporated from the chelate form was noted in strain SK11, but strain ATCC 19213 showed only temperature-independent binding of low concentrations of deferri (3)H-schizokinen. These results indicate an initial temperature-independent binding of the ferric hydroxamate which is followed rapidly by temperature-dependent transport of the chelate into the cell and an enzyme catalyzed separation of iron from the chelate. The resulting deferri hydroxamate is discharged from the cell only when a characteristic intracellular concentration of the hydroxamate is exceeded, which happens in the schizokinen-requiring strain only at elevated concentrations of the chelate. This strain also appears to draw the deferri hydroxamate into the cell by a temperature-dependent mechanism. The aerobactin-producing organism Aerobacter aerogenes 62-1 also demonstrated rapid initial uptake and temperature-dependent discharge of (3)H-aerobactin during iron transport from (3)H-aerobactin-(59)Fe(3+), suggesting a similar ferric hydroxamate transport system in this organism.

  20. Kinetic method for the large-scale analysis of the binding mechanism of histone deacetylase inhibitors.

    PubMed

    Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

    2014-09-01

    Performing kinetic studies on protein ligand interactions provides important information on complex formation and dissociation. Beside kinetic parameters such as association rates and residence times, kinetic experiments also reveal insights into reaction mechanisms. Exploiting intrinsic tryptophan fluorescence a parallelized high-throughput Förster resonance energy transfer (FRET)-based reporter displacement assay with very low protein consumption was developed to enable the large-scale kinetic characterization of the binding of ligands to recombinant human histone deacetylases (HDACs) and a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes. For the binding of trichostatin A (TSA), suberoylanilide hydroxamic acid (SAHA), and two other SAHA derivatives to HDAH, two different modes of action, simple one-step binding and a two-step mechanism comprising initial binding and induced fit, were verified. In contrast to HDAH, all compounds bound to human HDAC1, HDAC6, and HDAC8 through a two-step mechanism. A quantitative view on the inhibitor-HDAC systems revealed two types of interaction, fast binding and slow dissociation. We provide arguments for the thesis that the relationship between quantitative kinetic and mechanistic information and chemical structures of compounds will serve as a valuable tool for drug optimization. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. 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

  2. Histone deacetylase inhibitors mediate DNA damage repair in ameliorating hemorrhagic cystitis

    PubMed Central

    Haldar, Subhash; Dru, Christopher; Mishra, Rajeev; Tripathi, Manisha; Duong, Frank; Angara, Bryan; Fernandez, Ana; Arditi, Moshe; Bhowmick, Neil A.

    2016-01-01

    Hemorrhagic cystitis is an inflammatory and ulcerative bladder condition associated with systemic chemotherapeutics, like cyclophosphomide. Earlier, we reported reactive oxygen species resulting from cyclophosphamide metabolite, acrolein, causes global methylation followed by silencing of DNA damage repair genes. Ogg1 (8-oxoguanine DNA glycosylase) is one such silenced base excision repair enzyme that can restore DNA integrity. The accumulation of DNA damage results in subsequent inflammation associated with pyroptotic death of bladder smooth muscle cells. We hypothesized that reversing inflammasome-induced imprinting in the bladder smooth muscle could prevent the inflammatory phenotype. Elevated recruitment of Dnmt1 and Dnmt3b to the Ogg1 promoter in acrolein treated bladder muscle cells was validated by the pattern of CpG methylation revealed by bisulfite sequencing. Knockout of Ogg1 in detrusor cells resulted in accumulation of reactive oxygen mediated 8-Oxo-dG and spontaneous pyroptotic signaling. Histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), restored Ogg1 expression in cells treated with acrolein and mice treated with cyclophosphamide superior to the standard of care, mesna or nicotinamide-induced DNA demethylation. SAHA restored cyclophosphamide-induced bladder pathology to that of untreated control mice. The observed epigenetic imprinting induced by inflammation suggests a new therapeutic target for the treatment of hemorrhagic cystitis. PMID:27995963

  3. Histone deacetylase inhibitors mediate DNA damage repair in ameliorating hemorrhagic cystitis.

    PubMed

    Haldar, Subhash; Dru, Christopher; Mishra, Rajeev; Tripathi, Manisha; Duong, Frank; Angara, Bryan; Fernandez, Ana; Arditi, Moshe; Bhowmick, Neil A

    2016-12-20

    Hemorrhagic cystitis is an inflammatory and ulcerative bladder condition associated with systemic chemotherapeutics, like cyclophosphomide. Earlier, we reported reactive oxygen species resulting from cyclophosphamide metabolite, acrolein, causes global methylation followed by silencing of DNA damage repair genes. Ogg1 (8-oxoguanine DNA glycosylase) is one such silenced base excision repair enzyme that can restore DNA integrity. The accumulation of DNA damage results in subsequent inflammation associated with pyroptotic death of bladder smooth muscle cells. We hypothesized that reversing inflammasome-induced imprinting in the bladder smooth muscle could prevent the inflammatory phenotype. Elevated recruitment of Dnmt1 and Dnmt3b to the Ogg1 promoter in acrolein treated bladder muscle cells was validated by the pattern of CpG methylation revealed by bisulfite sequencing. Knockout of Ogg1 in detrusor cells resulted in accumulation of reactive oxygen mediated 8-Oxo-dG and spontaneous pyroptotic signaling. Histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), restored Ogg1 expression in cells treated with acrolein and mice treated with cyclophosphamide superior to the standard of care, mesna or nicotinamide-induced DNA demethylation. SAHA restored cyclophosphamide-induced bladder pathology to that of untreated control mice. The observed epigenetic imprinting induced by inflammation suggests a new therapeutic target for the treatment of hemorrhagic cystitis.

  4. Inhibitors of Histone Deacetylases Enhance Neurotoxicity of DNA Damage

    PubMed Central

    Vashishta, A.

    2014-01-01

    The nonselective inhibitors of class I/II histone deacetylases (HDACs) including trichostatin A and the clinically used suberoylanilide hydroxamic acid (SAHA, vorinostat) are neuroprotective in several models of neuronal injury. Here, we report that in cultured cortical neurons from newborn rats and in the cerebral cortex of whole neonate rats, these HDAC inhibitors exacerbated cytotoxicity of the DNA double-strand break (DSB)-inducing anticancer drug etoposide by enhancing apoptosis. Similar neurotoxic interactions were also observed in neurons that were treated with other DNA damaging drugs including cisplatin and camptothecin. In addition, in rat neonates, SAHA increased cortical neuron apoptosis that was induced by a single injection of the NMDA receptor antagonist dizocilpine (MK801). In etoposide-treated neurons, the nonselective HDAC inhibition resulted in more DSBs. It also potentiated etoposide-induced accumulation and phosphorylation of the pro-apoptotic transcription factor p53. Moreover, nonselective HDAC inhibition exacerbated neuronal apoptosis that was induced by the overexpressed p53. Importantly, such effects cannot be fully explained by inhibition of HDAC1, which is known to play a role in DSB repair and regulation of p53. The specific HDAC1 inhibitor MS275 only moderately enhanced etoposide-induced neuronal death. Although in etoposide-treated neurons MS275 increased DSBs, it did not affect activation of p53. Our findings suggest that besides HDAC1, there are other class I/II HDACs that participate in neuronal DNA damage response attenuating neurotoxic consequences of genotoxic insults to the developing brain. PMID:25063076

  5. 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

  6. 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.

  7. Neuronal developmental gene and miRNA signatures induced by histone deacetylase inhibitors in human embryonic stem cells

    PubMed Central

    Meganathan, K; Jagtap, S; Srinivasan, S P; Wagh, V; Hescheler, J; Hengstler, J; Leist, M; Sachinidis, A

    2015-01-01

    Human embryonic stem cells (hESCs) may be applied to develop human-relevant sensitive in vitro test systems for monitoring developmental toxicants. The aim of this study was to identify potential developmental toxicity mechanisms of the histone deacetylase inhibitors (HDAC) valproic acid (VPA), suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA) relevant to the in vivo condition using a hESC model in combination with specific differentiation protocols and genome-wide gene expression and microRNA profiling. Analysis of the gene expression data showed that VPA repressed neural tube and dorsal forebrain (OTX2, ISL1, EMX2 and SOX10)-related transcripts. In addition, VPA upregulates axonogenesis and ventral forebrain-associated genes, such as SLIT1, SEMA3A, DLX2/4 and GAD2. HDACi-induced expression of miR-378 and knockdown of miR-378 increases the expression of OTX2 and EMX2, which supports our hypothesis that HDACi targets forebrain markers through miR-378. In conclusion, multilineage differentiation in vitro test system is very sensitive for monitoring molecular activities relevant to in vivo neuronal developmental toxicity. Moreover, miR-378 seems to repress the expression of the OTX2 and EMX2 and therefore could be a regulator of the development of neural tube and dorsal forebrain neurons. PMID:25950486

  8. Inhibition of multiple pathogenic pathways by histone deacetylase inhibitor SAHA in a corneal alkali-burn injury model

    PubMed Central

    Li, Xinyu; Zhou, Qinbo; Hanus, Jakub; Anderson, Chastain; Zhang, Hongmei; Dellinger, Michael; Brekken, Rolf; Wang, Shusheng

    2013-01-01

    Neovascularization (NV) in the cornea is a major cause of vision impairment and corneal blindness. Hemangiogenesis and lymphangiogenesis induced by inflammation underlie the pathogenesis of corneal NV. The current mainstay treatment, corticosteroid, treats the inflammation associated with corneal NV, but is not satisfactory due to such side effects as cataract and the increase in intraocular pressure. It is imperative to develop a novel therapy that specifically targets the hemangiogenesis, lymphangiogenesis and inflammation pathways underlying corneal NV. Histone deacetylase inhibitors (HDACi) have been in clinical trials for cancer and other diseases. In particular, HDACi suberoylanilide hydroxamic acid (SAHA, vorinostat, Zolinza) has been approved by the FDA for the treatment of cutaneous T-cell lymphoma. The functional mechanism of SAHA in cancer and especially in corneal NV remains unclear. Here, we show that topical application of SAHA inhibits neovascularization in an alkali-burn corneal injury model. Mechanistically, SAHA inhibits corneal NV by repressing hemangiogenesis, inflammation pathways and previously overlooked lymphangiogenesis. Topical SAHA is well tolerated on the ocular surface. In addition, the potency of SAHA in corneal NV appears to be comparable to the current steroid therapy. SAHA may possess promising therapeutic potential in alkali-burn corneal injury and other inflammatory neovascularization disorders. PMID:23186311

  9. Solvent extraction of metals with hydroxamic acids.

    PubMed

    Vernon, F; Khorassani, J H

    1978-07-01

    Solvent extraction with hydroxamic acids has been investigated. with comparison of aliphatic and aromatic reagents for the extraction of iron, copper, cobalt and nickel. Caprylohydroxamic acid has been evaluated for use in extraction systems for titanium, vanadium, chromium, molybdenum and uranium, both in terms of acidity of aqueous phase and oxidation state of the metal. It has been established that caprylohydroxamic acid in 1-hexanol is a suitable extractant for the removal of titanium(IV), vanadium(V), chromium(VI), molybdenum(VI) and uranium(VI) from 6M hydrochloric acid.

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

    PubMed

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

    2015-12-01

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

  11. Differential effects of histone deacetylase inhibitors on cellular drug transporters and their implications for using epigenetic modifiers in combination chemotherapy

    PubMed Central

    Valdez, Benigno C.; Li, Yang; Murray, David; Brammer, Jonathan E.; Liu, Yan; Hosing, Chitra; Nieto, Yago; Champlin, Richard E.; Andersson, Borje S.

    2016-01-01

    HDAC inhibitors, DNA alkylators and nucleoside analogs are effective components of combination chemotherapy. To determine a possible mechanism of their synergism, we analyzed the effects of HDAC inhibitors on the expression of drug transporters which export DNA alkylators. Exposure of PEER lymphoma T-cells to 15 nM romidepsin (Rom) resulted in 40%-50% reduction in mRNA for the drug transporter MRP1 and up to ~500-fold increase in the MDR1 mRNA within 32-48 hrs. MRP1 protein levels concomitantly decreased while MDR1 increased. Other HDAC inhibitors − panobinostat, belinostat and suberoylanilide hydroxamic acid (SAHA) − had similar effects on these transporters. The protein level of MRP1 correlated with cellular resistance to busulfan and chlorambucil, and Rom exposure sensitized cells to these DNA alkylators. The decrease in MRP1 correlated with decreased cellular drug export activity, and increased level of MDR1 correlated with increased export of daunorubicin. A similar decrease in the level of MRP1 protein, and increase in MDR1, were observed when mononuclear cells derived from patients with T-cell malignancies were exposed to Rom. Decreased MRP1 and increased MDR1 expressions were also observed in blood mononuclear cells from lymphoma patients who received SAHA-containing chemotherapy in a clinical trial. This inhibitory effect of HDAC inhibitors on the expression of MRP1 suggests that their synergism with DNA alkylating agents is partly due to decreased efflux of these alkylators. Our results further imply the possibility of antagonistic effects when HDAC inhibitors are combined with anthracyclines and other MDR1 drug ligands in chemotherapy. PMID:27564097

  12. NBM-T-L-BMX-OS01, Semisynthesized from Osthole, Is a Novel Inhibitor of Histone Deacetylase and Enhances Learning and Memory in Rats

    PubMed Central

    Yang, Ying-Chen; Chen, Chia-Nan; Wu, Carol-Imei; Huang, Wei-Jan; Kuo, Tsun-Yung; Kuan, Ming-Chung; Tsai, Tung-Hu; Huang, Jing-Shi; Huang, Chung-Yang

    2013-01-01

    NBM-T-L-BMX-OS01 (BMX) was derived from the semisynthesis of osthole, isolated from Cnidium monnieri (L.) Cuss., and was identified to be a potent inhibitor of HDAC8. This study shows that HDAC8 is highly expressed in the pancreas and the brain. The function of HDAC8 in the brain has not been adequately studied. Because BMX enhances neurite outgrowth and cAMP response element-binding protein (CREB) activation, the effect of BMX on neural plasticity such as learning and memory is examined. To examine declarative and nondeclarative memory, a water maze, a passive one-way avoidance task, and a novel object recognition task were performed. Results from the water maze revealed that BMX and suberoylanilide-hydroxamic-acid-(SAHA-) treated rats showed shorter escape latency in finding the hidden platform. The BMX-treated animals spent more time in the target quadrant in the probe trial performance. An analysis of the passive one-way avoidance results showed that the BMX-treated animals stayed longer in the illuminated chamber by 1 day and 7 days after footshock. The novel object recognition task revealed that the BMX-treated animals showed a marked increase in the time spent exploring novel objects. Furthermore, BMX ameliorates scopolamine-(Sco-) induced learning and memory impairment in animals, indicating a novel role of BMX in learning and memory. PMID:23606881

  13. Histone deacetylase inhibitor- and PMA-induced upregulation of PMCA4b enhances Ca2+ clearance from MCF-7 breast cancer cells.

    PubMed

    Varga, Karolina; Pászty, Katalin; Padányi, Rita; Hegedűs, Luca; Brouland, Jean-Philippe; Papp, Béla; Enyedi, Agnes

    2014-02-01

    The expression of the plasma membrane Ca2+ ATPase (PMCA) isoforms is altered in several types of cancer cells suggesting that they are involved in cancer progression. In this study we induced differentiation of MCF-7 breast cancer cells by histone deacetylase inhibitors (HDACis) such as short chain fatty acids (SCFAs) or suberoylanilide hydroxamic acid (SAHA), and by phorbol 12-myristate 13-acetate (PMA) and found strong upregulation of PMCA4b protein expression in response to these treatments. Furthermore, combination of HDACis with PMA augmented cell differentiation and further enhanced PMCA4b expression both at mRNA and protein levels. Immunocytochemical analysis revealed that the upregulated protein was located mostly in the plasma membrane. To examine the functional consequences of elevated PMCA4b expression, the characteristics of intracellular Ca2+ signals were investigated before and after differentiation inducing treatments, and also in cells overexpressing PMCA4b. The increased PMCA4b expression - either by treatment or overexpression - led to enhanced Ca2+ clearance from the stimulated cells. We found pronounced PMCA4 protein expression in normal breast tissue samples highlighting the importance of this pump for the maintenance of mammary epithelial Ca2+ homeostasis. These results suggest that modulation of Ca2+ signaling by enhanced PMCA4b expression may contribute to normal development of breast epithelium and may be lost in cancer.

  14. Proteasome inhibitor MG-132 enhances histone deacetylase inhibitor SAHA-induced cell death of chronic myeloid leukemia cells by an ROS-mediated mechanism and downregulation of the Bcr-Abl fusion protein

    PubMed Central

    ZHOU, WENJING; ZHU, WEIWEI; MA, LIYA; XIAO, FENG; QIAN, WENBIN

    2015-01-01

    Recently, there has been progress in the treatment of chronic myeloid leukemia (CML). However, novel therapeutic strategies are required in order to address the emerging problem of imatinib resistance. Histone deacetylase inhibitors (HDACi) and proteasome inhibitors are promising alternatives, and may be amenable to integration with current therapeutic approaches. However, the mechanisms underlying the interaction between these two agents remain unclear. The present study assessed the cytotoxic effect of the HDACi, suberoylanilide hydroxamic acid (SAHA), in combination with the proteasome inhibitor, MG-132, in imatinib-sensitive K562 and imatinib-resistant K562G cells, and investigated the mechanism underlying this effect. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method and protein expression levels were determined by western blotting. Reactive oxygen species (ROS) generation levels were observed under a fluorescence microscope The results indicated that SAHA and MG-132 act in a synergistic manner to induce cell death in K562 and K562G cells. This effect was associated with Bcr-Abl downregulation and the production of ROS. Notably, the ROS scavenger, N-acetyl-L-cysteine, almost fully reversed the cell death and Bcr-Abl downregulation that was induced by the combination of SAHA and MG-132. By contrast, the pan-caspase inhibitor, z-VAD-fmk, only partially reversed the cell death induced by these two drugs in CML cells. These results indicated that increased intracellular ROS levels are important in the induction of cell death and the downregulation of Bcr-Abl. In conclusion, the present results suggested that combined SAHA and MG-132 may be a promising treatment for CML. PMID:26722260

  15. Selenium-containing histone deacetylase inhibitors for melanoma management

    PubMed Central

    Gowda, Raghavendra; Madhunapantula, SubbaRao V.; Desai, Dhimant; Amin, Shantu; Robertson, Gavin P.

    2012-01-01

    Melanoma incidence and mortality rates continue to increase each year. Lack of clinically viable agents, drug combinations, effective targeted delivery approaches and success inhibiting targets in tumor tissue have made this disease one of the most difficult to treat, which makes prevention an important option for decreasing disease incidence and mortality rates. Inhibiting histone deacetylases (HDAC) is an approach currently being explored to more effectively treat melanoma but use for prevention has not been explored. In this study, novel selenium containing derivatives of the FDA approved HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) called 5-phenylcarbamoylpentyl selenocyanide (PCP-SeCN) and Bis{5-phenylcarbamoylpentyl} diselenide (B(PCP)-2Se) were created and efficacy tested for preventing early melanocytic lesion development in skin. Topical application of PCP-SeCN and B(PCP)-2Se inhibited melanocytic lesion development in laboratory-generated skin by up to 87% with negligible toxicological effect. Mechanistically, PCP-SeCN and B(PCP)-2Se inhibited HDAC activity and had new inhibitory properties by moderating Akt activity to induce cellular apoptosis as demonstrated by an increase in the sub-G0-G1 cell population, and cleaved caspase-3 as well as PARP levels. Furthermore, PCP-SeCN and B(PCP)-2Se inhibited cell proliferation by inhibiting cyclin D1 expression and increasing p21 levels. Thus, PCP-SeCN and B(PCP)-2Se are potential melanoma chemopreventive agents with enhanced efficacy compared with SAHA due to new PI3 kinase pathway inhibitory properties. PMID:22669577

  16. Inhibitors of Histone Deacetylases Attenuate Noise-Induced Hearing Loss.

    PubMed

    Chen, Jun; Hill, Kayla; Sha, Su-Hua

    2016-08-01

    Loss of auditory sensory hair cells is the major pathological feature of noise-induced hearing loss (NIHL). Currently, no established clinical therapies for prevention or amelioration of NIHL are available. The absence of treatments is due to our lack of a comprehensive understanding of the molecular mechanisms underlying noise-induced damage. Our previous study indicates that epigenetic modification of histones alters hair cell survival. In this study, we investigated the effect of noise exposure on histone H3 lysine 9 acetylation (H3K9ac) in the inner ear of adult CBA/J mice and determined if inhibition of histone deacetylases by systemic administration of suberoylanilide hydroxamic acid (SAHA) could attenuate NIHL. Our results showed that H3K9ac was decreased in the nuclei of outer hair cells (OHCs) and marginal cells of the stria vascularis in the basal region after exposure to a traumatic noise paradigm known to induce permanent threshold shifts (PTS). Consistent with these results, levels of histone deacetylases 1, 2, and 3 (HDAC1, HDAC2 and HDAC3) were increased predominately in the nuclei of cochlear cells. Silencing of HDAC1, HDAC2, or HDAC3 with siRNA reduced the expression of the target HDAC in OHCs, but did not attenuate noise-induced PTS, whereas treatment with the pan-HDAC inhibitor SAHA, also named vorinostat, reduced OHC loss, and attenuated PTS. These findings suggest that histone acetylation is involved in the pathogenesis of noise-induced OHC death and hearing loss. Pharmacological targeting of histone deacetylases may afford a strategy for protection against NIHL.

  17. Tandem mass spectrometry of coprogen and deferoxamine hydroxamic siderophores.

    PubMed

    Simionato, Ana V C; de Souza, Gezimar D; Rodrigues-Filho, Edson; Glick, James; Vouros, Paul; Carrilho, Emanuel

    2006-01-01

    Mechanisms of fragmentation of hydroxamic siderophores are proposed comparing deuterated and nondeuterated samples. Standard siderophores (e.g. deferoxamine and coprogen) were directly injected into both ion trap and linear quadrupole mass spectrometers with electrospray ionization (ESI). Four and two fragmentation steps were carried out for deferoxamine and coprogen (analyzed by positive and negative ESI, respectively). Deferoxamine cleavages occurred in both peptide and hydroxamic bonds while the coprogen fragmentation pattern is more elaborate, since it contains Fe(III) in its structure.

  18. A comparative 2D QSAR study on a series of hydroxamic acid-based histone deacetylase inhibitors vis-à-vis comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA).

    PubMed

    Bajpai, Anubha; Agarwal, Neeraj; Gupta, Satya P

    2014-06-01

    A quantitative structure-activity relationship (QSAR) study was performed on a series of indole amide analogues reported by Dai et al. [Bioorg Med Chem Lett (2003), 13, 1897-1901] to act as histone deacetylase (HDAC) inhibitors. The multiple regression analysis (MRA) revealed a model showing the significant dependence of the activity on molar refractivity (MR) and global topological charge index (GTCI) of the compounds, suggesting that inhibition of the HDAC by this series of compounds might involve the dispersion interaction with the receptor, where charge transfer between pairs of atoms might greatly help to polarize the molecule. The MRA results were then compared with those obtained by Guo et al. [Bioorg Med Chem (2005), 13, 5424-5434] by comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). It was found that MRA gave as good results and had as good predictive ability as CoMFA and CoMSIA. Besides, MRA was also able to throw the light on the physicochemical properties of the molecules that were involved in drug-receptor interactions, while CoMFA and CoMSIA could not. The dispersion interaction between the molecule and the active site of the receptor is suggested to be the main interaction.

  19. Transcriptome Analysis of Pig In Vivo, In Vitro–Fertilized, and Nuclear Transfer Blastocyst-Stage Embryos Treated with Histone Deacetylase Inhibitors Postfusion and Activation Reveals Changes in the Lysosomal Pathway

    PubMed Central

    Whitworth, Kristin M.; Mao, Jiude; Lee, Kiho; Spollen, William G.; Samuel, Melissa S.; Walters, Eric M.; Spate, Lee D.

    2015-01-01

    Abstract Genetically modified pigs are commonly created via somatic cell nuclear transfer (SCNT). Treatment of reconstructed embryos with histone deacetylase inhibitors (HDACi) immediately after activation improves cloning efficiency. The objective of this experiment was to evaluate the transcriptome of SCNT embryos treated with suberoylanilide hydroxamic acid (SAHA), 4-iodo-SAHA (ISAHA), or Scriptaid as compared to untreated SCNT, in vitro–fertilized (IVF), and in vivo (IVV) blastocyst-stage embryos. SAHA (10 μM) had the highest level of blastocyst development at 43.9%, and all treatments except 10 μM ISAHA had the same percentage of blastocyst development as Scriptaid (p<0.05). Two treatments, 1.0 μM ISAHA and 1.0 μM SAHA, had higher mean cell number than No HDACi treatment (p<0.021). Embryo transfers performed with 10 μM SAHA- and 1 μM ISAHA-treated embryos resulted in the birth of healthy piglets. GenBank accession numbers from up- and downregulated transcripts were loaded into the Database for Annotation, Visualization and Integrated Discovery to identify enriched biological themes. HDACi treatment yielded the highest enrichment for transcripts within the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway, lysosome. The mean intensity of LysoTracker was lower in IVV embryos compared to IVF and SCNT embryos (p<0.0001). SAHA and ISAHA can successfully be used to create healthy piglets from SCNT. PMID:26731590

  20. Transcriptome Analysis of Pig In Vivo, In Vitro-Fertilized, and Nuclear Transfer Blastocyst-Stage Embryos Treated with Histone Deacetylase Inhibitors Postfusion and Activation Reveals Changes in the Lysosomal Pathway.

    PubMed

    Whitworth, Kristin M; Mao, Jiude; Lee, Kiho; Spollen, William G; Samuel, Melissa S; Walters, Eric M; Spate, Lee D; Prather, Randall S

    2015-08-01

    Genetically modified pigs are commonly created via somatic cell nuclear transfer (SCNT). Treatment of reconstructed embryos with histone deacetylase inhibitors (HDACi) immediately after activation improves cloning efficiency. The objective of this experiment was to evaluate the transcriptome of SCNT embryos treated with suberoylanilide hydroxamic acid (SAHA), 4-iodo-SAHA (ISAHA), or Scriptaid as compared to untreated SCNT, in vitro-fertilized (IVF), and in vivo (IVV) blastocyst-stage embryos. SAHA (10 μM) had the highest level of blastocyst development at 43.9%, and all treatments except 10 μM ISAHA had the same percentage of blastocyst development as Scriptaid (p<0.05). Two treatments, 1.0 μM ISAHA and 1.0 μM SAHA, had higher mean cell number than No HDACi treatment (p<0.021). Embryo transfers performed with 10 μM SAHA- and 1 μM ISAHA-treated embryos resulted in the birth of healthy piglets. GenBank accession numbers from up- and downregulated transcripts were loaded into the Database for Annotation, Visualization and Integrated Discovery to identify enriched biological themes. HDACi treatment yielded the highest enrichment for transcripts within the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway, lysosome. The mean intensity of LysoTracker was lower in IVV embryos compared to IVF and SCNT embryos (p<0.0001). SAHA and ISAHA can successfully be used to create healthy piglets from SCNT.

  1. An epigenetic modifier induces production of (10'S)-verruculide B, an inhibitor of protein tyrosine phosphatases by Phoma sp. nov. LG0217, a fungal endophyte of Parkinsonia microphylla.

    PubMed

    Gubiani, Juliana R; Wijeratne, E M Kithsiri; Shi, Taoda; Araujo, Angela R; Arnold, A Elizabeth; Chapman, Eli; Gunatilaka, A A Leslie

    2017-03-15

    Incorporation of the histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), to a culture broth of the endophytic fungus Phoma sp. nov. LG0217 isolated from Parkinsonia microphylla changed its metabolite profile and resulted in the production of (10'S)-verruculide B (1), vermistatin (2) and dihydrovermistatin (3). When cultured in the absence of the epigenetic modifier, it produced a new metabolite, (S,Z)-5-(3',4'-dihydroxybutyldiene)-3-propylfuran-2(5H)-one (4) together with nafuredin (5). The structure of 4 was elucidated by spectroscopic analyses and its absolute configuration was determined by application of the modified Mosher's ester method. The absolute structure of (10'S)-verruculide B was determined as 5-[(10'S,2'E,6'E)-10',11'-dihydroxy-3',7',11'-trimethyldodeca-2',6'-dien-1'-yl]-(3R)-6,8-dihydroxy-3-methylisochroman-1-one (1) with the help of CD and NOE data. Compound 1 inhibited the activity of protein tyrosine phosphatases (PTPs) 1B (PTP1B), Src homology 2-containing PTP 1 (SHP1) and T-cell PTP (TCPTP) with IC50 values of 13.7±3.4, 8.8±0.6, and 16.6±3.8μM, respectively. Significance of these activities and observed modest selectivity of 1 for SHP1 over PTP1B and TCPTP is discussed.

  2. Histone Deacetylase Inhibitors Inhibit the Proliferation of Gallbladder Carcinoma Cells by Suppressing AKT/mTOR Signaling.

    PubMed

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

    2015-01-01

    Gallbladder carcinoma is an aggressive malignancy with high mortality mainly due to the limited potential for curative resection and its resistance to chemotherapeutic agents. Here, we show that the histone deacetylase inhibitors (HDACIs) trichostatin-A (TSA) and suberoylanilide hydroxamic acid (SAHA) reduce the proliferation and induce apoptosis of gallbladder carcinoma cells by suppressing the AKT/mammalian target of rapamycin (mTOR) signaling. Gallbladder carcinoma SGC-996 cells were treated with different concentrations of TSA and SAHA for different lengths of time. Cell proliferation and morphology were assessed with MTT assay and microscopy, respectively. Cell cycle distribution and cell apoptosis were analyzed with flow cytometry. Western blotting was used to detect the proteins related to apoptosis, cell cycle, and the AKT/mTOR signaling pathway. Our data showed that TSA and SAHA reduced SGC-996 cell viability and arrested cell cycle at the G1 phase in a dose- and time-dependent manner. TSA and SAHA promoted apoptosis of SGC-996 cells, down-regulated the expression of cyclin D1, c-Myc and Bmi1, and decreased the phosphorylation of AKT, mTOR p70S6K1, S6 and 4E-BP1. Additionally, the mTOR inhibitor rapamycin further reduced the cell viability of TSA- and SAHA-treated SGC-996 cells and the phosphorylation of mTOR, whereas the mTOR activator 1,2-dioctanoyl-sn-glycero-3-phosphate (C8-PA) exerted the opposite influence. Our results demonstrate that histone deacetylase inhibitors (HDACIs) suppress the proliferation of gallbladder carcinoma cell via inhibition of AKT/mTOR signaling. These findings offer a mechanistic rationale for the application of HDACIs in gallbladder carcinoma treatment.

  3. Histone Deacetylase Inhibitor SAHA Attenuates TLR4 Signaling in LPS-Stimulated Mouse Macrophages

    PubMed Central

    Chong, Wei; Li, Yongqing; Liu, Baoling; Zhao, Ting; Fukudome, Eugene Y.; Liu, Zhengcai; Smith, William M.; Velmahos, George C.; deMoya, Marc; Alam, Hasan B.

    2012-01-01

    Objective We have previously demonstrated that pre- and post-treatment of animals with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor (HDACI), can improve survival in a mouse model of lipopolysaccharides (LPS)-induced severe shock. This study was to assess whether SAHA affects LPS/Toll like receptor4 (TLR4) signaling through acetylation of HSP90 and degradation of its client protein interleukin-1 receptor associated kinase 1 (IRAK1). Methods and Results RAW264.7 cells were exposed to LPS (1 μg/ml) for two hours followed by treatment with SAHA (10 μM) or one of HSP90 inhibitors, geldanamycin (GA) (3 μM). Sham (no SAHA, no LPS) macrophages served as a control. The cells were harvested at different time points, and time zero served as the reference point. LPS dramatically increased protein expression of myeloid differentiation factor 88 (MyD88) and IRAK1, and stimulated nuclear translocation of nuclear factor kB (NF-kB), leading to increases of gene expression and protein production of TNF-α and IL-6. Treatment with SAHA significantly attenuated these LPS- stimulated alterations. LPS or SAHA did not change the levels of HSP90 protein, but immunoprecipitation studies demonstrated that SAHA treatment enhanced acetylation of HSP90, and increased the dissociation of IRAK1, compared to the LPS control. Conclusions SAHA suppresses LPS/TLR4 signaling in LPS-stimulated macrophages through multiple possible mechanisms. It inhibits the function of HSP90 through hyperacetylation of the chaperone protein, which results in dissociation and degradation of the client protein IRAK1 and, at least in part, leads to a resultant decrease in nuclear translocation of NF-κB and attenuation of key pro-inflammatory cytokine expression. PMID:22868051

  4. Novel hydroxamates potentiated in vitro activity of fluconazole against Candida albicans

    PubMed Central

    Paul-Satyaseela, Maneesh; Hariharan, Periasamy; Bharani, Thirunavukkarasu; Franklyne, Jonathan S.; Selvakumar, Thangapazham; Bharathimohan, Kuppusamy; Kumar, Chenniappan Vinoth; Kachhadia, Virendra; Narayanan, Shridhar; Rajagopal, Sridharan; Balasubramanian, Gopalan

    2017-01-01

    A set of 12 novel hydroxamate compounds (NHCs), structurally designed as inhibitors of histone deacetylase (HDAC) enzyme, were synthesized at our facility. These were adamantane derivatives with N-hydroxyacetamide as pharmacophore, and each of these compounds was tested for potentiating activity on fluconazole. The concentration of fluconazole which completely inhibited (concentration of complete inhibition [CCI]) the growth of Candida albicans ATCC 90028 and C. albicans ATCC 64550 was determined by micro-dilution method in the absence and presence of NHCs. The CCI of fluconazole without the NHC combination was 64 μg/ml and 1024 μg/ml against C. albicans ATCC 90028 and C. albicans ATCC 64550, respectively. The majority of the NHCs potentiated the fluconazole activity markedly as CCI of fluconazole against C. albicans ATCC 90028 reduced to 0.25 μg/ml. Similarly, CCI of fluconazole against C. albicans ATCC 64550 reduced to 4–8 μg/ml in combination with majority of NHCs while the best activity was displayed by the compound 1 with a reduction of CCI to 0.5 μg/ml. The study results revealed the potential usage of hydroxamate derivatives, structurally designed as HDAC inhibitors to enhance the activity of fluconazole against C. albicans. PMID:28250687

  5. Histone Deacetylase Inhibitors Reduce the Number of Herpes Simplex Virus-1 Genomes Initiating Expression in Individual Cells

    PubMed Central

    Shapira, Lev; Ralph, Maya; Tomer, Enosh; Cohen, Shai; Kobiler, Oren

    2016-01-01

    Although many viral particles can enter a single cell, the number of viral genomes per cell that establish infection is limited. However, mechanisms underlying this restriction were not explored in depth. For herpesviruses, one of the possible mechanisms suggested is chromatinization and silencing of the incoming genomes. To test this hypothesis, we followed infection with three herpes simplex virus 1 (HSV-1) fluorescence expressing recombinants in the presence or absence of histone deacetylases inhibitors (HDACi’s). Unexpectedly, a lower number of viral genomes initiated expression in the presence of these inhibitors. This phenomenon was observed using several HDACi: Trichostatin A (TSA), Suberohydroxamic Acid, Valporic Acid, and Suberoylanilide Hydroxamic Acid. We found that HDACi presence did not change the progeny outcome from the infected cells but did alter the kinetic of the gene expression from the viral genomes. Different cell types (HFF, Vero, and U2OS), which vary in their capability to activate intrinsic and innate immunity, show a cell specific basal average number of viral genomes establishing infection. Importantly, in all cell types, treatment with TSA reduced the number of viral genomes. ND10 nuclear bodies are known to interact with the incoming herpes genomes and repress viral replication. The viral immediate early protein, ICP0, is known to disassemble the ND10 bodies and to induce degradation of some of the host proteins in these domains. HDACi treated cells expressed higher levels of some of the host ND10 proteins (promyelocytic leukemia and ATRX), which may explain the lower number of viral genomes initiating expression per cell. Corroborating this hypothesis, infection with three HSV-1 recombinants carrying a deletion in the gene coding for ICP0, show a reduction in the number of genomes being expressed in U2OS cells. We suggest that alterations in the levels of host proteins involved in intrinsic antiviral defense may result in

  6. Catecholates and mixed catecholate hydroxamates as artificial siderophores for mycobacteria.

    PubMed

    Wittmann, Steffen; Heinisch, Lothar; Scherlitz-Hofmann, Ina; Stoiber, Thomas; Ankel-Fuchs, Dorothe; Möllmann, Ute

    2004-02-01

    Different mono-, bis- or triscatecholates and mixed mono- or biscatecholate hydroxamates were synthesized as potential siderophores for mycobacteria. SiderOphore activity was tested by growth promotion assays using wild type strains and iron transport mutants of mycobacteria as well as Gram-negative bacteria. Some triscatecholates and biscatecholate hydroxamates were active in mutants of Mycobacterium smegmatis deficient in mycobactin and exochelin biosynthesis or exochelin permease, respectively, indicating an uptake route independent of the exochelin/mycobactin pathway. Structure activity relationships were studied. Ampicillin conjugates of some of these compounds were inactive against mycobacteria but active against Gram-negative bacteria.

  7. Histone Deacetylase Inhibitor SAHA as Potential Targeted Therapy Agent for Larynx Cancer Cells.

    PubMed

    Grabarska, Aneta; Łuszczki, Jarogniew J; Nowosadzka, Ewa; Gumbarewicz, Ewelina; Jeleniewicz, Witold; Dmoszyńska-Graniczka, Magdalena; Kowalczuk, Krystyna; Kupisz, Krzysztof; Polberg, Krzysztof; Stepulak, Andrzej

    2017-01-01

    Objective: Laryngeal squamous cell carcinoma is one of the most common malignant tumors in the head and neck region. Due to the poor response to chemotherapeutics in patients and low survival rate, successful treatment of larynx cancer still remains a challenge. Therefore, the identification of novel treatment options is needed. We investigated the anticancer effects of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on two different laryngeal cancer cell lines RK33 and RK45. We also studied the antiproliferative action of SAHA in combination with cisplatin and defined the type of pharmacological interaction between these drugs. Materials and Methods: Viability and proliferation of larynx cancer cell lines were studied by methylthiazolyldiphenyl-tetrazolium bromide method and 5-bromo-2-deoxyuridine incorporation assay, respectively. The type of interaction between SAHA and cisplatin was determined by an isobolographic analysis. Western blotting, flow cytometry and quantitative polymerase chain reaction method were used to determine acetylation of histone H3, cell cycle progression and genes expression, respectively. Apoptosis was assessed by means of nucleosomes released to cytosol. Results: SAHA alone or in combination with cisplatin inhibited larynx cancer cells proliferation, whereas displayed relatively low toxicity against normal cells - primary cultures of human skin fibroblasts. The mixture of SAHA with cisplatin exerted additive and synergistic interaction in RK33 and RK45 cells, respectively. We showed that SAHA induced hyperacetylation of histone H3 K9, K14 and K23 and triggered apoptosis. SAHA also caused cell cycle arrest by upregulation of CDKN1A and downregulation of CCND1 encoding p21WAF1/CIP1 and cyclin D1 proteins, respectively. Conclusion: Our studies demonstrated that SAHA may be considered as a potential therapeutic agent against larynx tumors.

  8. Grouping of histone deacetylase inhibitors and other toxicants disturbing neural crest migration by transcriptional profiling.

    PubMed

    Dreser, Nadine; Zimmer, Bastian; Dietz, Christian; Sügis, Elena; Pallocca, Giorgia; Nyffeler, Johanna; Meisig, Johannes; Blüthgen, Nils; Berthold, Michael R; Waldmann, Tanja; Leist, Marcel

    2015-09-01

    Functional assays, such as the "migration inhibition of neural crest cells" (MINC) developmental toxicity test, can identify toxicants without requiring knowledge on their mode of action (MoA). Here, we were interested, whether (i) inhibition of migration by structurally diverse toxicants resulted in a unified signature of transcriptional changes; (ii) whether statistically-identified transcript patterns would inform on compound grouping even though individual genes were little regulated, and (iii) whether analysis of a small group of biologically-relevant transcripts would allow the grouping of compounds according to their MoA. We analyzed transcripts of 35 'migration genes' after treatment with 16 migration-inhibiting toxicants. Clustering, principal component analysis and correlation analyses of the data showed that mechanistically related compounds (e.g. histone deacetylase inhibitors (HDACi), PCBs) triggered similar transcriptional changes, but groups of structurally diverse toxicants largely differed in their transcriptional effects. Linear discriminant analysis (LDA) confirmed the specific clustering of HDACi across multiple separate experiments. Similarity of the signatures of the HDACi trichostatin A and suberoylanilide hydroxamic acid to the one of valproic acid (VPA), suggested that the latter compound acts as HDACi when impairing neural crest migration. In conclusion, the data suggest that (i) a given functional effect (e.g. inhibition of migration) can be associated with highly diverse signatures of transcript changes; (ii) statistically significant grouping of mechanistically-related compounds can be achieved on the basis of few genes with small regulations. Thus, incorporation of mechanistic markers in functional in vitro tests may support read-across procedures, also for structurally un-related compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Histone Deacetylase Inhibitor SAHA as Potential Targeted Therapy Agent for Larynx Cancer Cells

    PubMed Central

    Grabarska, Aneta; Łuszczki, Jarogniew J.; Nowosadzka, Ewa; Gumbarewicz, Ewelina; Jeleniewicz, Witold; Dmoszyńska-Graniczka, Magdalena; Kowalczuk, Krystyna; Kupisz, Krzysztof; Polberg, Krzysztof; Stepulak, Andrzej

    2017-01-01

    Objective: Laryngeal squamous cell carcinoma is one of the most common malignant tumors in the head and neck region. Due to the poor response to chemotherapeutics in patients and low survival rate, successful treatment of larynx cancer still remains a challenge. Therefore, the identification of novel treatment options is needed. We investigated the anticancer effects of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on two different laryngeal cancer cell lines RK33 and RK45. We also studied the antiproliferative action of SAHA in combination with cisplatin and defined the type of pharmacological interaction between these drugs. Materials and Methods: Viability and proliferation of larynx cancer cell lines were studied by methylthiazolyldiphenyl-tetrazolium bromide method and 5-bromo-2-deoxyuridine incorporation assay, respectively. The type of interaction between SAHA and cisplatin was determined by an isobolographic analysis. Western blotting, flow cytometry and quantitative polymerase chain reaction method were used to determine acetylation of histone H3, cell cycle progression and genes expression, respectively. Apoptosis was assessed by means of nucleosomes released to cytosol. Results: SAHA alone or in combination with cisplatin inhibited larynx cancer cells proliferation, whereas displayed relatively low toxicity against normal cells - primary cultures of human skin fibroblasts. The mixture of SAHA with cisplatin exerted additive and synergistic interaction in RK33 and RK45 cells, respectively. We showed that SAHA induced hyperacetylation of histone H3 K9, K14 and K23 and triggered apoptosis. SAHA also caused cell cycle arrest by upregulation of CDKN1A and downregulation of CCND1 encoding p21WAF1/CIP1 and cyclin D1 proteins, respectively. Conclusion: Our studies demonstrated that SAHA may be considered as a potential therapeutic agent against larynx tumors. PMID:28123594

  10. Probing the S2' Subsite of the Anthrax Toxin Lethal Factor Using Novel N-Alkylated Hydroxamates.

    PubMed

    Kurbanov, Elbek K; Chiu, Ting-Lan; Solberg, Jonathan; Francis, Subhashree; Maize, Kimberly M; Fernandez, Jenna; Johnson, Rodney L; Hawkinson, Jon E; Walters, Michael A; Finzel, Barry C; Amin, Elizabeth Ambrose

    2015-11-12

    The lethal factor (LF) enzyme secreted by Bacillus anthracis is a zinc hydrolase that is chiefly responsible for anthrax-related cell death. Although many studies of the design of small molecule LF inhibitors have been conducted, no LF inhibitor is yet available as a therapeutic agent. Inhibitors with considerable chemical diversity have been developed and investigated; however, the LF S2' subsite has not yet been systematically explored as a potential target for lead optimization. Here we present synthesis, experimental evaluation, modeling, and structural biology for a novel series of sulfonamide hydroxamate LF inhibitor analogues specifically designed to extend into, and probe chemical preferences of, this S2' subsite. We discovered that this region accommodates a wide variety of chemical functionalities and that a broad selection of ligand structural modifications directed to this area can be incorporated without significant deleterious alterations in biological activity. We also identified key residues in this subsite that can potentially be targeted to improve inhibitor binding.

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

    PubMed

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

    2017-01-21

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

  12. Hydrolysis of aceto-hydroxamic acid under UREX+ conditions

    SciTech Connect

    Alyapyshev, M.; Paulenova, A.; Tkac, P.; Cleveland, M.A.; Bruso, J.E.

    2007-07-01

    Aceto-hydroxamic acid (AHA) is used as a stripping agent In the UREX process. While extraction yields of uranium remain high upon addition of AHA, hexavalent plutonium and neptunium are rapidly reduced to the pentavalent state while the tetravalent species and removed from the product stream. However, under acidic conditions, aceto-hydroxamic acid undergoes hydrolytic degradation. In this study, the kinetics of the hydrolysis of aceto-hydroxamic acid in nitric and perchloric acid media was investigated at several temperatures. The decrease of the concentration of AHA was determined via its ferric complex using UV-Vis spectroscopy. The data obtained were analyzed using the method of initial rates. The data follow the pseudo-first order reaction model. Gamma irradiation of AHA/HNO{sub 3} solutions with 33 kGy/s caused two-fold faster degradation of AHA. The rate equation and thermodynamic data will be presented for the hydrolysis reaction with respect to the concentrations of aceto-hydroxamic acid, nitrate and hydronium ions, and radiation dose. (authors)

  13. Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

    DOEpatents

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2016-03-15

    Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

  14. Copper extraction by fatty hydroxamic acids derivatives synthesized based on palm kernel oil.

    PubMed

    Haron, Jelas; Jahangirian, Hossein; Silong, Sidik; Yusof, Nor Azah; Kassim, Anuar; Moghaddam, Roshanak Rafiee; Peyda, Mazyar; Abdollahi, Yadollah; Amin, Jamileh; Gharayebi, Yadollah

    2012-01-01

    Fatty hydroxamic acids derivatives based on palm kernel oil which are phenyl fatty hydroxamic acids (PFHAs), methyl fatty hydroxamic acids (MFHAs), isopropyl fatty hydroxamic acids (IPFHAs) and benzyl fatty hydroxamic acids (BFHAs) were applied as chelating agent for copper liquid-liquid extraction. The extraction of copper from aqueous solution by MFHAs, PFHAs, BFHAs or IPFHAs were carried out in hexane as an organic phase through the formation of copper methyl fatty hydroxamate (Cu-MFHs), copper phenyl fatty hydroxamate (Cu-PFHs), copper benzyl fatty hydroxamate (Cu-BFHs) and copper isopropyl fatty hydroxamate (Cu-IPFHs). The results showed that the fatty hydroxamic acid derivatives could extract copper at pH 6.2 effectively with high percentage of extraction (the percentages of copper extraction by MFHAs, PFHAs, IPFHs and BFHAs were found to be 99.3, 87.5, 82.3 and 90.2%, respectively). The extracted copper could be quantitatively stripped back into sulphuric acid (3M) aqueous solution. The obtained results showed that the copper recovery percentages from Cu-MFHs, Cu-PFHs, Cu-BFHs and Cu-IPFHs are 99.1, 99.4, 99.6 and 99.9 respectively. The copper extraction was not affected by the presence of a large amount of Mg (II), Ni (II), Al (III), Mn (II) and Co (II) ions in the aqueous solution.

  15. Radiosensitization of glioblastoma cells using a histone deacetylase inhibitor (SAHA) comparing carbon ions with X-rays.

    PubMed

    Barazzuol, Lara; Jeynes, J Charles G; Merchant, Michael J; Wéra, Anne-Catherine; Barry, Miriam A; Kirkby, Karen J; Suzuki, Masao

    2015-01-01

    Prognosis for patients with glioblastoma (GBM) remains poor, and new treatments are needed. Here we used a combination of two novel treatment modalities: Carbon ions and a histone deacetylase inhibitor (HDACi). We compared these to conventional X-rays, measuring the increased effectiveness of carbon ions as well as radiosensitization using HDACi. Suberoylanilide hydroxamic acid (SAHA) was used at a non-toxic concentration of 0.5 μM in combination with 85 keV μm(-1) carbon ions, and 250 kVp X-rays for comparison. Effects were assayed using clonogenic survival, γH2AX foci repair kinetics and measuring chromatin decondensation. Dose toxicity curves showed that human GBM LN18 cells were more sensitive to SAHA compared to U251 cells at higher doses, but there was little effect at low doses. When combined with radiation, clonogenic assays showed that the Sensitizer Enhancement Ratio with carbon ions at 50% survival (SER(50)) was about 1.2 and 1.5 for LN18 and U251, respectively, but was similar for X-rays at about 1.3. The repair half-life of γH2AX foci was slower for cells treated with SAHA and was most noticeable in U251 cells treated with carbon ions where after 24 h, more than double the number of foci remained in comparison to the untreated cells. Hoechst fluorescent dye incorporation into the nucleus showed significant chromatin decondensation and density homogenization with SAHA treatment for both cell lines. Our results suggest a vital role of histone deacetylases (HDAC) in the modulation of DNA damage response and support the use of SAHA for the treatment of GBM through the combination with heavy ion therapy.

  16. Synergy between histone deacetylase inhibitors and DNA-damaging agents is mediated by histone deacetylase 2 in colorectal cancer

    PubMed Central

    Alzoubi, Samer; Brody, Leigh; Rahman, Sunniyat; Mahul-Mellier, Anne-Laure; Mercado, Nicolas; Ito, Kazuhiro; El-Bahrawy, Mona; Silver, Andrew; Boobis, Alan; Bell, Jimmy D.; Hajji, Nabil

    2016-01-01

    Previous studies have associated the overexpression of histone deacetylase 2 (HDAC2) and the presence of TP53 mutations with the progression to advanced stage drug resistant colorectal cancer (CRC). However, the mechanistic link between HDAC2 expression and the TP53 mutational status has remained unexplored. Here, we investigated the function of HDAC2 in drug resistance by assessing the synergistic effects of DNA-targeted chemotherapeutic agents and HDAC inhibitors (HDACis) on two TP53-mutated colorectal adenocarcinoma CRC cell lines (SW480 and HT-29) and on the TP53-wild type carcinoma cell line (HCT116 p53+/+) and its TP53 deficient sub-line (HCT116 p53−/−). We showed that in the untreated SW480 and HT-29 cells the steady-state level of HDAC2 was low compared to a TP53-wild type carcinoma cell line (HCT116 p53+/+). Increased expression of HDAC2 correlated with drug resistance, and depletion by shRNA sensitised the multi-drug resistance cell line HT-29 to CRC chemotherapeutic drugs such as 5-fluorouracil (5-FU) and oxaliplatin (Oxa). Combined treatment with the HDACi suberoylanilide hydroxamic acid plus 5-FU or Oxa reduced the level of HDAC2 expression, modified chromatin structure and induced mitotic cell death in HT-29 cells. Non-invasive bioluminescence imaging revealed significant reductions in xenograft tumour growth with HDAC2 expression level reduced to <50% in treated animals. Elevated levels of histone acetylation on residues H3K9, H4K12 and H4K16 were also found to be associated with resistance to VPA/Dox or SAHA/Dox treatment. Our results suggest that HDAC2 expression rather than the p53 mutation status influences the outcome of combined treatment with a HDACi and DNA-damaging agents in CRC. PMID:27283986

  17. Histone deacetylase inhibitors promote eNOS expression in vascular smooth muscle cells and suppress hypoxia-induced cell growth.

    PubMed

    Tan, Xiaoling; Feng, Lan; Huang, Xiaoyong; Yang, Yidong; Yang, Chengzhong; Gao, Yuqi

    2017-03-07

    Hypoxia stimulates excessive growth of vascular smooth muscle cells (VSMCs) contributing to vascular remodelling. Recent studies have shown that histone deacetylase inhibitors (HDIs) suppress VSMC proliferation and activate eNOS expression. However, the effects of HDI on hypoxia-induced VSMC growth and the role of activated eNOS in VSMCs are unclear. Using an EdU incorporation assay and flow cytometry analysis, we found that the HDIs, butyrate (Bur) and suberoylanilide hydroxamic acid (SAHA) significantly suppressed the proliferation of hypoxic VSMC lines and induced apoptosis. Remarkable induction of cleaved caspase 3, p21 expression and reduction of PCNA expression were also observed. Increased eNOS expression and enhanced NO secretion by hypoxic VSMC lines were detected using Bur or SAHA treatment. Knockdown of eNOS by siRNA transfection or exposure of hypoxic VSMCs to NO scavengers weakened the effects of Bur and SAHA on the growth of hypoxic VSMCs. In animal experiments, administration of Bur to Wistar rats exposed to hypobaric hypoxia for 28 days ameliorated the thickness and collagen deposition in pulmonary artery walls. Although the mean pulmonary arterial pressure (mPAP) was not obviously decreased with Bur in hypoxic rats, right ventricle hypertrophy index (RVHI) was decreased and the oxygen partial pressure of arterial blood was elevated. Furthermore, cell viability was decreased and eNOS and cleaved caspase 3 were induced in HDI-treated rat pulmonary arterial SMCs. These findings imply that HDIs prevent hypoxia-induced VSMC growth, in correlation with activated eNOS expression and activity in hypoxic VSMCs.

  18. Effects of glycine hydroxamate, carbon dioxide, and oxygen on photorespiratory carbon and nitrogen metabolism in spinach mesophyll cells.

    PubMed

    Lawyer, A L; Cornwell, K L; Gee, S L; Bassham, J A

    1982-05-01

    The effects of added glycine hydroxamate on the photosynthetic incorporation of (14)CO(2) into metabolites by isolated mesophyll cells of spinach (Spinacia oleracea L.) was investigated under conditions favorable to photorespiratory (PR) metabolism (0.04% CO(2) and 20% O(2)) and under conditions leading to nonphotorespiratory (NPR) metabolism (0.2% CO(2) and 2.7% O(2)). Glycine hydroxamate (GH) is a competitive inhibitor of the photorespiratory conversion of glycine to serine, CO(2) and NH(4) (+). During PR fixation, addition of the inhibitor increased glycine and decreased glutamine labeling. In contrast, labeling of glycine decreased under NPR conditions. This suggests that when the rate of glycolate synthesis is slow, the primary route of glycine synthesis is through serine rather than from glycolate. GH addition increased serine labeling under PR conditions but not under NPR conditions. This increase in serine labeling at a time when glycine to serine conversion is partially blocked by the inhibitor may be due to serine accumulation via the "reverse" flow of photorespiration from 3-P-glycerate to hydroxypyruvate when glycine levels are high. GH increased glyoxylate and decreased glycolate labeling. These observations are discussed with respect to possible glyoxylate feedback inhibition of photorespiration.

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

    PubMed Central

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

    2011-01-01

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

  20. 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

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

    PubMed

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

    2009-06-01

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

  2. The Therapeutic Potential of AN-7, a Novel Histone Deacetylase Inhibitor, for Treatment of Mycosis Fungoides/Sezary Syndrome Alone or with Doxorubicin.

    PubMed

    Moyal, Lilach; Feldbaum, Nataly; Goldfeiz, Neta; Rephaeli, Ada; Nudelman, Abraham; Weitman, Michal; Tarasenko, Nataly; Gorovitz, Batia; Maron, Leah; Yehezkel, Shiran; Amitay-Laish, Iris; Lubin, Ido; Hodak, Emmilia

    2016-01-01

    The 2 histone deacetylase inhibitors (HDACIs) approved for the treatment of cutaneous T-cell lymphoma (CTCL) including mycosis fungoides/sezary syndrome (MF/SS), suberoylanilide hydroxamic acid (SAHA) and romidepsin, are associated with low rates of overall response and high rates of adverse effects. Data regarding combination treatments with HDACIs is sparse. Butyroyloxymethyl diethylphosphate (AN-7) is a novel HDACI, which was found to have selective anticancer activity in several cell lines and animal models. The aim of this study was to compare the anticancer effects of AN-7 and SAHA, either alone or combined with doxorubicin, on MF/SS cell lines and peripheral blood lymphocytes (PBL) from patients with Sezary syndrome (SPBL). MyLa cells, Hut78 cells, SPBL, and PBL from healthy normal individuals (NPBL) were exposed to the test drugs, and the findings were analyzed by a viability assay, an apoptosis assay, and Western blot. AN-7 was more selectively toxic to MyLa cells, Hut78 cells, and SPBL (relative to NPBL) than SAHA and also acted more rapidly. Both drugs induced apoptosis in MF/SS cell lines, SAHA had a greater effect on MyLa cell line, while AN-7 induced greater apoptosis in SPBL; both caused an accumulation of acetylated histone H3, but AN-7 was associated with earlier kinetics; and both caused a downregulation of the HDAC1 protein in MF/SS cell lines. AN-7 acted synergistically with doxorubicin in both MF/SS cell lines and SPBL, and antagonistically with doxorubicin in NPBL. By contrast, SAHA acted antagonistically with doxorubicin on MF/SS cell lines, SPBL, and NPBL, leaving <50% viable cells. In conclusion, AN-7 holds promise as a therapeutic agent in MF/SS and has several advantages over SAHA. Our data provide a rationale for combining AN-7, but not SAHA, with doxorubicin to induce the cell death in MF/SS.

  3. Glucocorticoids and histone deacetylase inhibitors cooperate to block the invasiveness of basal-like breast cancer cells through novel mechanisms

    PubMed Central

    Law, ME; Corsino, PE; Jahn, SC; Davis, BJ; Chen, S; Patel, B; Pham, K; Lu, J; Sheppard, B; Nørgaard, P; Hong, J; Higgins, P; Kim, J-S; Luesch, H; Law, BK

    2013-01-01

    Aggressive cancers often express E-cadherin in cytoplasmic vesicles rather than on the plasma membrane and this may contribute to the invasive phenotype of these tumors. Therapeutic strategies are not currently available that restore the anti-invasive function of E-cadherin in cancers. MDA-MB-231 cells are a frequently used model of invasive triple-negative breast cancer, and these cells express low levels of E-cadherin that is mislocalized to cytoplasmic vesicles. MDA-MB-231 cell lines stably expressing wild-type E-cadherin or E-cadherin fused to glutathione S-transferase or green fluorescent protein were used as experimental systems to probe the mechanisms responsible for cytoplasmic E-cadherin localization in invasive cancers. Although E-cadherin expression partly reduced cell invasion in vitro, E-cadherin was largely localized to the cytoplasm and did not block the invasiveness of the corresponding orthotopic xenograft tumors. Further studies indicated that the glucocorticoid dexamethasone and the highly potent class I histone deacetylase (HDAC) inhibitor largazole cooperated to induce E-cadherin localization to the plasma membrane in triple-negative breast cancers, and to suppress cellular invasion in vitro. Dexamethasone blocked the production of the cleaved form of the CDCP1 (that is, CUB domain-containing protein 1) protein (cCDCP1) previously implicated in the pro-invasive activities of CDCP1 by upregulating the serine protease inhibitor plasminogen activator inhibitor-1. E-cadherin preferentially associated with cCDCP1 compared with the full-length form. In contrast, largazole did not influence CDCP1 cleavage, but increased the association of E-cadherin with γ-catenin. This effect on E-cadherin/γ-catenin complexes was shared with the nonisoform selective HDAC inhibitors trichostatin A (TSA) and vorinostat (suberoylanilide hydroxamic acid, SAHA), although largazole upregulated endogenous E-cadherin levels more strongly than TSA. These results demonstrate

  4. Interaction of imidazole containing hydroxamic acids with Fe(III): hydroxamate versus imidazole coordination of the ligands.

    PubMed

    Farkas, Etelka; Bátka, Dávid; Csóka, Hajnalka; Nagy, Nóra V

    2007-01-01

    Solution equilibrium studies on Fe(III) complexes formed with imidazole-4-carbohydroxamic acid (Im-4-Cha), N-Me-imidazole-4-carbohydroxamic acid (N-Me-Im-4-Cha), imidazole-4-acetohydroxamic acid (Im-4-Aha), and histidinehydroxamic acid (Hisha) have been performed by using pH-potentiometry, UV-visible spectrophotometry, EPR, ESI-MS, and H1-NMR methods. All of the obtained results demonstrate that the imidazole moiety is able to play an important role very often in the interaction with Fe(III), even if this metal ion prefers the hydroxamate chelates very much. If the imidazole moiety is in alpha-position to the hydroxamic one (Im-4-Cha and N-Me-Im-4-Cha) its coordination to the metal ion is indicated unambiguously by our results. Interestingly, parallel formation of (Nimidazole, Ohydroxamate), and (Ohydroxamate, Ohydroxamate) type chelates seems probable with N-Me-Im-4-Cha. The imidazole is in beta-position to the hydroxamic moiety in Im-4-Aha and an intermolecular noncovalent (mainly H-bonding) interaction seems to organize the intermediate-protonated molecules in this system. Following the formation of mono- and bishydroxamato mononuclear complexes, only EPR silent species exists in the Fe(III)-Hisha system above pH 4, what suggests the rather significant "assembler activity" of the imidazole (perhaps together with the ammonium moiety).

  5. Characterization of iron uptake from hydroxamate siderophores by Chlorella vulgaris

    SciTech Connect

    Allnutt, F.C.T.

    1985-01-01

    Iron uptake by Chlorella vulgaris from ferric-hydroxamate siderophores and the possible production of siderophores by these algae was investigated. No production of siderophores or organic acids was observed. Iron from the two hydroxamate siderophores tested, ferrioximine B (Fe/sup 3 +/-DFOB) and ferric-rhodotorulate (Fe/sup 3 +/-RA), was taken up at the same rate as iron chelated by citrate or caffeate. Two synthetic chelates, Fe/sup 3 +/-EDTA and Fe/sup 3 +/-EDDHA, provided iron at a slower rate. Iron uptake was inhibited by 50 ..mu..M CCCP or 1 mM vanadate. Cyanide (100 ..mu..M KCN) or 25 ..mu..M antimycin A failed to demonstrate a link between uptake and respiration. Labeled iron (/sup 55/Fe) was taken up while labeled ligands ((/sup 14/C) citrate or RA) were not accumulated. Cation competition from Ni/sup 2 +/ and Co/sup 2 +/ observed using Fe/sup 3 +/-DFOB and Fe/sup 3 +/-RA while iron uptake from Fe/sup 3 +/-citrate was stimulated. Iron-stress induced iron uptake from the hydroxamate siderophores. Ferric reduction from the ferric-siderophores was investigated with electron paramagnetic resonance (EPR) and bathophenathroline disulfonate (BPDS). Ferric reduction was induced by iron-stress and inhibited by CCCP. A close correlation between iron uptake and ferric reduction was measured by the EPR method. Ferric reduction measured by the BPDS method was greater than that measure by EPR. BPDS reduction was interpreted to indicate a potential for reduction while EPR measures the physiological rate of reduction. BPDS inhibition of iron uptake and ferricyanide interference with reduction indicate that reduction and uptake occur exposed to the external medium. Presumptive evidence using a binding dose response curve for Fe/sup 3 +/-DFOB indicated that a receptor may be involved in this mechanism.

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

    PubMed Central

    Singh, Jaspreet; Khan, Mushfiquddin; Singh, Inderjit

    2011-01-01

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

  7. 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.

  8. Synthesis and characterization of fatty hydroxamic acids from triacylglycerides.

    PubMed

    Hoidy, Wisam H; Ahmad, Mansor B; Al-Mulla, Emad A Jaffar; Yunus, Wan Md Zin Wan; Ibrahim, Nor azowa Bt

    2010-01-01

    In this study, fatty haydroxamic acids (FHAs), which have biological activities as antibiotics and antifungal, have been synthesized via refluxing of triacylglycrides, palm olein, palm stearin or corn oil with hydroxylamine hydrochloride. The products were characterized using the complex formation test of hydroxamic acid group with zinc(I), copper(II) and iron(III), various technique methods including nuclear magnetic resonance ((1)H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and elemental analysis. Parameters that may affect the conversion of oils to FHAs including the effect of reaction time, effect of organic solvent and effect of hydro/oil molar issue were also investigated in this study. Results of characterization indicate that FHAs were successfully produced from triacylglycrides. The conversion percentages of palm stearin, palm olein and corn oil into their fatty hydroxamic acids are 82, 81 and 78, respectively. Results also showed that hexane is the best organic solvent to produce the FHAs from the three oils used in this study. The optimum reaction time to achieve the maximum conversion percentage of the oils to FHAs was found to be 10 hours for all the three oils, while the optimum molar ration of hydro/to oil was found to be 7:1 for all the different three oils.

  9. Zinc cross-linked hydroxamated alginates for pulsed drug release

    PubMed Central

    Raut, Neha S; Deshmukh, Prasad R; Umekar, Milind J; Kotagale, Nandkishor R

    2013-01-01

    Introduction: Alginates can be tailored chemically to improve solubility, physicochemical, and biological properties and its complexation with metal ion is useful for controlling the drug release. Materials And Methods: Synthesized N,O-dimethyl, N-methyl, or N-Benzyl hydroxylamine derivatives of sodium alginate were subsequently complexed with zinc to form beads. Hydroxamation of sodium alginate was confirmed by Fourier transform infra-red spectroscopy (FTIR) and differential scanning calorimetry (DSC). Results: The synthesized polymeric material exhibited reduced aqueous, HCl and NaOH solubility. The hydroxamated derivatives demonstrated pulsed release where change in pH of the dissolution medium stimulated the atenolol release. Conclusion: Atenolol loaded Zn cross-linked polymeric beads demonstrated the sustained the plasma drug levels with increased half-life. Although the synthesized derivatives greatly altered the aqueous solubility of sodium alginate, no significant differences in in vitro and in vivo atenolol release behavior amongst the N,O-dimethyl, N-methyl, or N-Benzyl hydroxylamine derivatives of sodium alginate were observed. PMID:24350039

  10. Production of l-Arginine by Arginine Hydroxamate-Resistant Mutants of Bacillus subtilis

    PubMed Central

    Kisumi, Masahiko; Kato, Jyoji; Sugiura, Masaki; Chibata, Ichiro

    1971-01-01

    l-Arginine hydroxamate inhibited the growth of various bacteria, and the inhibition was readily reversed by arginine. l-Arginine hydroxamate (10−3m) completely inhibited the growth of Bacillus subtilis. This inhibitory effect was prevented by 2.5 × 10−4ml-arginine, which was the most effective of all the natural amino acids in reversing the inhibition. l-Arginine hydroxamate-resistant mutants of Bacillus subtilis were isolated and found to excrete l-arginine in relatively high yields. One of the mutants, strain AHr-5, produced 4.5 mg of l-arginine per ml in shaken culture in 3 days. PMID:5002904

  11. Suberoylanilide Hydroxyamic Acid Modification of Chromatin Architecture Affects DNA Break Formation and Repair

    SciTech Connect

    Singh, Sheetal; Le Hongan; Shih, S.-J.; Ho, Bay; Vaughan, Andrew T.

    2010-02-01

    Purpose: Chromatin-modifying compounds that inhibit the activity of histone deacetylases have shown potency as radiosensitizers, but the action of these drugs at a molecular level is not clear. Here we investigated the effect of suberoylanilide hydroxyamic acid (SAHA) on DNA breaks and their repair and induction of rearrangements. Methods and Materials: The effect of SAHA on both clonogenic survival and repair was assessed using cell lines SCC-25, MCF7, and TK6. In order to study unique DNA double-strand breaks, anti-CD95 antibody was employed to introduce a DNA double-strand break at a known location within the 11q23 region. The effects of SAHA on DNA cleavage and rearrangements were analyzed by ligation-mediated PCR and inverse PCR, respectively. Results: SAHA acts as radiosensitizer at 1 {mu}M, with dose enhancement factors (DEFs) at 10% survival of: SCC-25 - 1.24 +- 0.05; MCF7 - 1.16 +- 0.09 and TK6 - 1.17 +- 0.05, and it reduced the capacity of SCC-25 cells to repair radiation induced lesions. Additionally, SAHA treatment diffused site-specific fragmentation over at least 1 kbp in TK6 cells. Chromosomal rearrangements produced in TK6 cells exposed to SAHA showed a reduction in microhomology at the breakpoint between 11q23 and partner chromosomes. Conclusions: SAHA shows efficacy as a radiosensitizer at clinically obtainable levels. In its presence, targeted DNA strand breaks occur over an expanded region, indicating increased chromatin access. The rejoining of such breaks is degraded by SAHA when measured as rearrangements at the molecular level and rejoining that contributes to cell survival.

  12. Enhancing Hormonal Therapy for Breast Cancer by Combination with a Well-Known Approved Pharmaceutical with Little Toxicity

    DTIC Science & Technology

    2008-07-01

    Munster PN, Troso- Sandoval T, Rosen N et al (2001) The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces differentiation of human...malignant post- menopausal breast tissues. J Steroid Biochem Mol Biol 81(1):57–64 38. Benz CC , Scott GK, Sarup JC et al (1993) Estrogen-depen- dent, tamoxifen

  13. Antimalarial action of hydroxamate-based iron chelators and potentiation of desferrioxamine action by reversed siderophores.

    PubMed Central

    Golenser, J; Tsafack, A; Amichai, Y; Libman, J; Shanzer, A; Cabantchik, Z I

    1995-01-01

    Hydroxamate-based chelators of iron are potent inhibitors of in vitro growth of Plasmodium falciparum. Two types of such chelators, the natural desferrioxamine and the synthetic reversed siderophore RSFileum2, are prototypes of antimalarial agents whose action spectra differ in the speed of action, stage dependence, and degree of reversibility of effects. This work explores the possibility of improving the antimalarial efficacy of these agents by using them in various combinations on in vitro cultures of P. falciparum. Growth assessment was based both on total nucleic acid synthesis and on parasitemia. The results indicate that the synthetic reversed siderophore more than complements the antimalarial action of desferrioxamine when applied during either ring, trophozoite, or mixed stages. The combined drug effects were significantly higher than the additive effect of the individual drugs. Qualitatively similar results were obtained for both reversible effects and irreversible (i.e., sustained) effects. Following an 8-h window of exposure the combined drug treatment caused parasite growth arrest and prevented its recovery, even 3 days after the treatment. The fact that such a combination of iron chelators displays a wider action spectrum than either drug alone has implications for the design of chemotherapy regimens. PMID:7695330

  14. Effects of Hydroxamic Acids Isolated from Gramineae on Adenosine 5′-triphosphate Synthesis in Chloroplasts 1

    PubMed Central

    Queirolo, Carlos B.; Andreo, Carlos S.; Vallejos, Rubén H.; Niemeyer, Hermann M.; Corcuera, Luis J.

    1981-01-01

    Two hydroxamic acids isolated from maize extracts, 2,4-dihydroxy-7-methoxy-1,4-(2H)-benzoxazin-3(4H)-one (DIMBOA) and the 2-O-β-d-glucopyranoside of DIMBOA, inhibit photophosphorylation by spinach chloroplasts. Both cyclic and noncyclic photophosphorylations were inhibited to the same extent. The concentrations producing 50% inhibition for DIMBOA and its glucoside were about 1 and 4 millimolar, respectively. These compounds inhibit coupled electron transport but do not affect basal or uncoupled electron transport. Both acids inhibit the ATPase activities of membrane-bound coupling factor 1 (CF1) and of purified CF1. On the basis of these results, it is concluded that DIMBOA and its glucoside act as energy transfer inhibitors of photophosphorylation. PMID:16662030

  15. QSAR studies of PC-3 cell line inhibition activity of TSA and SAHA-like hydroxamic acids.

    PubMed

    Wang, Di-Fei; Wiest, Olaf; Helquist, Paul; Lan-Hargest, Hsuan-Yin; Wiech, Norbert L

    2004-02-09

    Quantitative structure-activity relationships (QSAR) for a series of new trichostatin A (TSA)-like hydroxamic acids for the inhibition of cell proliferation of the PC-3 cell line have been developed using molecular descriptors from Qikprop and electronic structure calculations. The best regression model shows that the PM3 atomic charge on the carbonyl carbon in the CONHOH moiety(Qco), globularity (Glob), and the hydrophilic component of the solvent-accessible surface area (FISA) describe the IC(50) of 19 inhibitors of the PC-3 cell line with activities ranging over five orders of magnitude with an R(2)=0.92 and F=59.2. This information will be helpful in the further design of novel anticancer drugs for treatment of prostate cancer and other diseases affected by HDAC inhibition.

  16. Selective flotation of phosphate minerals with hydroxamate collectors

    DOEpatents

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

  17. Chemical Characterization, Crossfeeding and Uptake Studies on Hydroxamate Siderophore of Alcaligenes faecalis.

    PubMed

    Sayyed, R Z; Chincholkar, S B; Meyer, J M; Kale, S P

    2011-06-01

    We report the production of two types of siderophores namely catecholate and hydroxamate in modified succinic acid medium (SM) from Alcaligenes faecalis. Two fractions of siderophores were purified on amberlite XAD, major fraction was hydroxamate type having a λ(max) at 224 nm and minor fraction appeared as catecholate with a λ(max) of 264 nm. The recovery yield obtained from major and minor fractions was 297 and 50 mg ml(-1) respectively. The IEF pattern of XAD-4 purified siderophore suggested the pI value of 6.5. Cross feeding studies revealed that A. faecalis accepts heterologous as well as self (hydroxamate) siderophore in both free and iron complexed forms however; the rate of siderophore uptake was more in case of siderophores complexed to iron. Siderophore iron uptake studies indicated the differences between hydroxamate siderophore of A. faecalis and Alc E, a siderophore of Alcaligenes eutrophus.

  18. Solvent-Controlled Chemoselectivity in the Photolytic Release of Hydroxamic Acids and Carboxamides from Solid Support.

    PubMed

    Qvortrup, Katrine; Petersen, Rico G; Dohn, Asmus O; Møller, Klaus B; Nielsen, Thomas E

    2017-06-16

    The synthetic utility and theoretical basis of a photolabile hydroxylamine-linker are presented. The developed protocols enable the efficient synthesis and chemoselective photolytic release of either hydroxamates or carboxamides from solid support. The bidetachable mode of the linker unit is uniquely dependent on the solvent. Hydroxamic acids are obtained by performing photolysis in protic solvents, whereas photolysis in aprotic solvents enables the selective release of carboxamides.

  19. The therapeutic effect of histone deacetylase inhibitor PCI-24781 on gallbladder carcinoma in BK5.erbB2 mice.

    PubMed

    Kitamura, Takuya; Connolly, Kevin; Ruffino, Lynnsie; Ajiki, Tetsuo; Lueckgen, Aline; DiGiovanni, John; Kiguchi, Kaoru

    2012-07-01

    Gallbladder carcinoma (GBCa), a type of biliary tract cancer (BTC), has proven challenging to treat, demonstrating the need for more effective therapeutic strategies. In our current study, we examined the therapeutic effects of the histone deacetylase (HDAC) inhibitor PCI-24781 against GBCa that developed in BK5.erbB2 mice. PCI-24781 [50 mg/kg/day] and control solutions were administered to BK5.erbB2 mice for 4 weeks. The therapeutic effect of PCI-24781 was evaluated by ultrasound biomicroscopy (USBM) throughout the experiment and histological analyses at the end of the experiment. To investigate potential mechanisms underlining the therapeutic effects of PCI-24781 on GBCa in BK5.erbB2 mice, PCI-24781-treated gallbladders were subjected to Western blot and RT-PCR analysis. The inhibitory effect of PCI-24781 on the growth of BTC cells was compared to the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and gemcitabine. To study the role of miRNAs in GBCa tumorigenesis, the expression profile of 368 miRNAs in GBCas from BK5.erbB2 (both treated and untreated) and wild type mice was analyzed. Treatment of BK5.erbB2 mice with PCI-24781 for 1 month prevented 79% of GBCa cases from progression and showed a clinical effect in 47% of cases. We also confirmed a potent inhibitory effect on tumor cell growth in human BTC cell lines treated with PCI-24781. This effect was associated with downregulation of ErbB2 mRNA and ErbB2 protein/activity and upregulation of acetylated histone and acetylated tubulin. Treatment with PCI-24781 resulted in decreased expression of Muc4, an intramembrane ligand for ErbB2, in BTC cells. PCI-24781 had more effects on growth inhibition of BTC cells than SAHA. In addition, PCI-24781 effectively inhibited the growth of gemcitabine-resistant cells. miRNA profiling revealed that the expression of several miRNAs was significantly altered in GBCa in the BK5.erbB2 mouse compared to normal gallbladder, including upregulated miR21, which was

  20. Release of bio-active dentine extracellular matrix components by histone deacetylase inhibitors (HDACi).

    PubMed

    Duncan, H F; Smith, A J; Fleming, G J P; Reid, C; Smith, G; Cooper, P R

    2017-01-01

    To characterize dentine matrix component (DMC) release and smear layer removal by histone deacetylase inhibitors (HDACis). DMCs were extracted from powdered human dentine over 14 days using three HDACis, valproic acid (VPA), trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA) and compared with a control extractant, 10% (w/v) EDTA. Protein compositions of the resultant extracts were analysed by 1D-polyacrylamide gel electrophoresis (1D-PAGE), TGF-β-1 and MMP-9 ELISAs and a high-throughput growth factor antibody array. Dentine discs with a standardized smear layer were prepared from human molars and treated with EDTA (17% w/v), polyacrylic acid (PA) (20% v/v) and the experimental HDACis prior to analysis by scanning electron microscopy. Parametric ELISA data were analysed using one-way anova and Tukey's post hoc test, whilst nonparametric smear layer data were analysed by Kruskal-Wallis test and Mann-Whitney U-test (P < 0.05). HDACis did not remove smear layer in the presence or absence of PA pre-treatment (P ≥ 0.478). 1D-PAGE analysis demonstrated different protein profiles for EDTA and HDACi extracts. All HDACi solutions released TGF-β-1 although less effectively than EDTA (P < 0.001), whilst MMP-9 was extracted in significantly higher concentration by EDTA and VPA compared with TSA (P < 0.012). Antibody array analysis demonstrated the ability of HDACis to extract a complex cocktail of established/novel growth factors from dentine, albeit significantly less efficiently than EDTA for certain cytokines (TGF-β-1, PDGF-AA, VEGF-A) and significantly more effectively for others (GDF-15, IGF-1, EGRF-1, NGFR, BDNF, SCF-R). HDACi release a range of bioactive DMCs that could promote dentine repair processes in vivo; however, they are ineffective at removing smear layer. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  1. Histone Deacetylase Inhibitor SAHA Is a Promising Treatment of Cushing Disease.

    PubMed

    Lu, Jie; Chatain, Grégoire P; Bugarini, Alejandro; Wang, Xiang; Maric, Dragan; Walbridge, Stuart; Zhuang, Zhengping; Chittiboina, Prashant

    2017-08-01

    Remission failure following transsphenoidal surgery in Cushing disease (CD) from pituitary corticotroph tumors (CtTs) remains clinically challenging. Histone deacetylase inhibitors (HDACis) are antitumor drugs approved for clinical use, with the potential to affect adrenocorticotropin hormone (ACTH) hypersecretion by inhibiting pro-opiomelanocortin (POMC) transcription. Testing the efficacy of suberoylanilide hydroxamic acid (SAHA) on human and murine ACTH-secreting tumor (AtT-20) cells. Cell viability, ACTH secretion (enzyme-linked immunosorbent assay), apoptosis, and gene expression profile were investigated on AtT-20 cells. In vivo efficacy was examined in an athymic nude mouse AtT-20 xenograft model. SAHA efficacy against human-derived corticotroph tumor (hCtT) (n = 8) was tested in vitro. National Institutes of Health. SAHA (0.5 to 8 µM). AtT-20 and hCtT cell survival, in vitro/invivo ACTH measurements. SAHA (1 µM) reduced AtT-20 viability to 75% at 24 hours, 43% at 48 hours (analysis of variance; P = 0.002). Apoptosis was confirmed with elevated BAX/Bcl2 ratio and FACS. Intriguingly, early (3-hour) significant decline (70%; P < 0.0001) of secreted ACTH and diminished POMC transcription was observed with SAHA (1 µM). Microarray analysis revealed a direct association between liver X receptor alpha (LXRα) and POMC expression. Accordingly, SAHA reduced LXRα in AtT-20 cells but not in normal murine corticotrophs. Xenografted nude-mice tumor involution (126 ± 33/160 ± 35 vs 337 ± 49 mm3; P = 0.0005) was observed with 5-day intraperitoneal SAHA, with reversal of elevated ACTH (P < 0.0001). SAHA did not affect serum ACTH in nontumor mice. Lastly, we confirmed that SAHA (1 µM/24 h) decreased hCtT survival (78.92%; P = 0.0007) and ACTH secretion (83.64%; P = 0.03). Our findings demonstrate SAHA's efficacy in reducing survival and ACTH secretion in AtT-20 and hCtT cells, providing a potential intervention for recurrent/unremitting CD.

  2. Histone hyperacetylation modulates spinal type II metabotropic glutamate receptor alleviating stress-induced visceral hypersensitivity in female rats

    PubMed Central

    Cao, Dong-Yuan; Bai, Guang; Ji, Yaping; Karpowicz, Jane

    2016-01-01

    Stress is often a trigger to exacerbate chronic pain including visceral hypersensitivity associated with irritable bowel syndrome, a female predominant functional bowel disorder. Epigenetic mechanisms that mediate stress responses are a potential target to interfere with visceral pain. The purpose of this study was to examine the effect of a histone deacetylase inhibitor, suberoylanilide hydroxamic acid, on visceral hypersensitivity induced by a subchronic stressor in female rats and to investigate the involvement of spinal glutamate receptors. Three daily sessions of forced swim induced visceral hypersensitivity. Intrathecal suberoylanilide hydroxamic acid prevented or reversed the stress-induced visceral hypersensitivity, increased spinal histone 3 acetylation and increased mGluR2 and mGluR3 expression. Chromatin immunoprecipitation (ChIP) analysis revealed enrichment of H3K9Ac and H3K18Ac at several promoter Grm2 and Grm3 regions. The mGluR2/3 antagonist LY341495 reversed the inhibitory effect of suberoylanilide hydroxamic acid on the stress-induced visceral hypersensitivity. In surprising contrast, stress and/or suberoylanilide hydroxamic acid had no effect on spinal NMDA receptor expression or function. These data reveal histone modification modulates mGluR2/3 expression in the spinal cord to attenuate stress-induced visceral hypersensitivity. HDAC inhibitors may provide a potential approach to relieve visceral hypersensitivity associated with irritable bowel syndrome. PMID:27385724

  3. Active Transport of Iron in Bacillus megaterium: Role of Secondary Hydroxamic Acids

    PubMed Central

    Davis, W. B.; Byers, B. R.

    1971-01-01

    Kinetics of radioactive iron transport were examined in three strains of Bacillus megaterium. In strain ATCC 19213, which secretes the ferric-chelating secondary hydroxamic acid schizokinen, 59Fe3+ uptake from 59FeCl3 or the ferric hydroxamate Desferal-59Fe3+ was rapid and reached saturation within 3 min. In strain SK11, which does not secrete schizokinen, transport from 59FeCl3 was markedly reduced; the two ferric hydroxamates Desferal-59Fe3+ or schizokinen-59Fe3+ increased both total 59Fe3+ uptake and the 59Fe3+ appearing in a cellular trichloroacetic acid-insoluble fraction, although 10 min was required to reach saturation. Certain characteristics of transport from both ferric hydroxamates and FeCl3 suggest that iron uptake was an active process. The growth-inhibitory effect of aluminum on strain SK11 was probably due to the formation of nonutilizable iron-aluminum complexes which blocked uptake from 59FeCl3. Desferal or schizokinen prevented this blockage. A strain (ARD-1) resistant to the ferric hydroxamate antibiotic A22765 was isolated from strain SK11. Strain ARD-1 failed to grow with Desferal-Fe3+ as an iron source, and it was unable to incorporate 59Fe3+ from this source. Growth and iron uptake in strain ARD-1 were similar to strain SK11 with schizokinen-Fe3+ or the iron salt as sources. It is suggested that the ferric hydroxamates, or the iron they chelate, may be transported by a special system which might be selective for certain ferric hydroxamates. Strain ARD-1 may be unable to recognize both the antibiotic A22765 and the structurally similar chelate Desferal-Fe3+, while retaining its capacity to utilize schizokinen-Fe3+. PMID:5000305

  4. Polymers containing hydroxamate groups: nanoreactors for hydrolysis of phosphoryl esters.

    PubMed

    Mello, Renata S; Orth, Elisa S; Loh, Watson; Fiedler, Haidi D; Nome, Faruk

    2011-12-20

    A polyhydroxamicalkanoate (PHA) polymer containing the functional groups hydroxamic acid and carboxylic acid with the ability to accelerate dephosphorylation reactions is proposed. The methodology used to prepare this polymer favored the position of the two functional groups next to each other, which allows for the cooperativity between these groups. This cooperative effect has an important role when one wants to mimic enzymes. The catalytic effect promoted by the polymer was evaluated on the cleavage of the bis(2,4-dinitrophenyl) phosphate (BDNPP) and diethyl 2,4-dinitrophenyl phosphate (DEDNPP) esters. Indeed, PHA was very efficient and promiscuous because it increased the rate of both reactions by a factor of up to 10(6)-fold. Isothermal titration calorimetry (ITC) experiments showed that the presence of PHA aids the formation of cetyltrimethylammonium bromide (CTABr) micelles. Thus, the effect of the cationic surfactant CTABr on the dephosphorylation of BDNPP by PHA was also investigated, and it was observed that, when CTABr is added to PHA, the reaction is ca. 15-fold faster compared to the reaction when only PHA is present.

  5. Chemical basis for the phytotoxicity of N-aryl hydroxamic acids and acetanilide analogues.

    PubMed

    Bravo, Héctor R; Villarroel, Elisa; Copaja, Sylvia V; Argandoña, Victor H

    2008-01-01

    Germination inhibition activity of N-aryl hydroxamic acids and acetanilide analogues was measured on lettuce seeds (Lactuca sativa). Lipophilicity of the compounds was determined by HPLC. A correlation between lipophilicity values and percentage of germination inhibition was established. A model mechanism of action for auxin was used for analyzing the effect of the substituent at the alpha carbon atom (Ca) on the polarization of hydroxamic and amide functions in relation to the germination inhibition activity observed. Results suggest that the lipophilic and acidic properties play an important role in the phytotoxicity of the compounds. A test with the microalga Chlorella vulgaris was used to evaluate the potential herbicide activity of the hydroxamic acids and acetanilides.

  6. Transition-Metal-Free Synthesis of N-Aryl Hydroxamic Acids via Insertion of Arynes.

    PubMed

    Zhang, Lanlan; Geng, Yu; Jin, Zhong

    2016-05-06

    An efficient and transition-metal-free N-arylation of amides via the insertion of arynes into the N-H bonds in the N-alkoxy amides is described. A variety of the reactive functional groups including the reactive aldehyde carbonyl group, furan ring, carbon-carbon double bonds, and free N-H bond of indole are found to be compatible with this process. In particular, the protocol is applicable in the synthesis of structurally diverse N-aryl hydroxamates and hydroxamic acids derived from N-protecting amino acids and peptides. In the presence of multiple amide N-H bonds, the N-arylation reaction can proceed selectively in the N-H bonds of terminal N-OBn amides giving rise to the desired N-aryl hydroxamates.

  7. New hydroxamic acid derivatives of fluoroquinolones: synthesis and evaluation of antibacterial and anticancer properties.

    PubMed

    Rajulu, Gavara Govinda; Bhojya Naik, Halehatty Seephya; Viswanadhan, Abhilash; Thiruvengadam, Jayaraman; Rajesh, Kondodiyil; Ganesh, Sambasivam; Jagadheshan, Hiriyan; Kesavan, Poonimangadu Koppolu

    2014-01-01

    A series of new hydroxamic acid derivatives (6a-f) at C-3 position of fluoroquinolones were designed and synthesized through multistep synthesis. The design concept involved replacement of the 3-carboxylic acid in fluoquinolones with hydroxamic acid as an acid mimicking group. The synthetic work employed in this work provides a good example for the synthesis of pure hydroxamic acid based fluoroquinolones. The synthesized compounds were characterized by (1)H-NMR, electrospray ionization (ESI)-MS and IR. The new compounds were tested for their in vitro antimicrobial and anti-proliferative activity. Out of the six derivatives, compound 6e exhibited moderate antibacterial activity by inhibiting the growth of Escherichia coli and Klebsiella pneumoniae (MIC: 4.00-8.00 µg/mL). Compounds 6b and 6f displayed good growth inhibition against A549 Lung adenocarcinoma and HCT-116 Colon carcinoma cell lines.

  8. Discovery and Characterization of New Hydroxamate Siderophores, Baumannoferrin A and B, produced by Acinetobacter baumannii.

    PubMed

    Penwell, William F; DeGrace, Nancy; Tentarelli, Sharon; Gauthier, Lise; Gilbert, Catherine M; Arivett, Brock A; Miller, Alita A; Durand-Reville, Thomas F; Joubran, Camil; Actis, Luis A

    2015-07-27

    Acinetobacter baumannii AYE does not produce acinetobactin but grows under iron limitation. Accordingly, analyses of AYE iron-restricted culture supernatants resulted in the isolation of two fractions, which contained only hydroxamates and showed siderophore activity. Structural analyses identified baumannoferrin A and baumannoferrin B, which differ only by a double bond. These siderophores are composed of citrate, 1,3-diaminopropane, 2,4-diaminobutyrate, decenoic acid, and α-ketoglutarate. Analysis of the AYE genome showed the presence of a 12-gene cluster coding for proteins similar to those involved in the production and utilization of the hydroxamate siderophores acinetoferrin and achromobactin. As A. baumannii AYE does not produce acinetobactin and harbors only one gene cluster encoding the production and utilization of a siderophore, this strain's growth under iron limitation depends on baumannoferrin, a novel hydroxamate that could play a role in its virulence.

  9. [Synthesis of hydroxamic acids and study of their complexes with iron (II) and (III) ions].

    PubMed

    Nenortiene, Palma; Sapragoniene, Marija; Stankevicius, Antanas

    2002-01-01

    Hydroxamic acids are widespread in the tissues of plants, in metabolites of bacteria and fungi, including complex compounds with metal ions. These acids have wide spectrum of biological activity and therefore are perspective reagents for analysis of chemical elements. Fourteen aliphatic and aromatic derivatives of hydroxamic acids have been synthesized from esters of carboxylic acids. Photometric reactions of hydroxamic acids with iron (II) and (III) were investigated. Complex formation of iron (II) and (III) depending on pH was studied with series of synthesized hydroxamic acids: octanohydroxamic, maleic hydroxamic, 2-hydroxybenzoxydroxamic, benzoxydroxamic, phthalmonoxydroxamic and 3-metoxybenzohydroxamic acids. Composition of iron (III) complexes with 2-hydroxybenzohydroxamic, octanoxydroxamic, 3-metoxybenzohydroxamic acids and iron (II) with 2-hydroxybenzohydroxamic acid was studied by methods of mole ratio and isomolar solutions. Sensitivity of reagents was evaluated by values of absorption coefficients (epsilon). Stability of complexes in water and organic solvents was investigated. Interaction between iron (III) and hydroxamic acids (octanoxydroxamic, 2-hydroxybenzohydroxamic, 3-metoxybenzohydroxamic) have been applied for quantitative photometric analysis of iron (III) salts. Color reaction of iron (II) with 2-hydroxybenzohydroxamic acid was applied for quantitative photometric determination of iron (II) salts. 3-Metoxybenzohydroxamic acid was proposed as a new indicator for complexonometric analysis of iron (III). Chelatometric titration of iron (III) using this indicator is not influenced by copper, cobalt, zinc, manganese, so this methods is recommended for iron quantity detection in antianemic drugs, which are composed of latter microelements. Synthesis procedure of 2-benzoylamino-3-arylacrylhydroxamic acids from saturated azlactones was created. Color and precipitate reactions of iron (II) and (III), copper (II), nickel (II) and cobalt (II) ions with

  10. Preparation of bifunctional isocyanate hydroxamate linkers: Synthesis of carbamate and urea tethered polyhydroxamic acid chelators

    PubMed Central

    Fernando, Rasika; Shirley, Jonathan M.; Torres, Emilio; Jacobs, Hollie K.; Gopalan, Aravamudan S.

    2012-01-01

    Two novel bifunctional N-methylhydroxamate-isocyanate linkers 20 and 21 were prepared in good yield and high purity from the corresponding amine salts using a biphasic reaction with phosgene. The facile ring opening reaction of N-Boc lactams using the anion of O-benzylhydroxylamine gave the protected amino hydroxamates 6a and 6c in good yields. The selective methylation of the hydroxamate nitrogen in the presence of the N-Boc group in these intermediates could be readily accomplished. The utility of the linkers was clearly demonstrated by the synthesis of the carbamate-tethered trishydroxamic acid 27 and the urea-tethered 29 PMID:23162172

  11. Structures of Clostridium Botulinum Neurotoxin Serotype A Light Chain Complexed with Small-Molecule Inhibitors Highlight Active-Site Flexibility

    SciTech Connect

    Silvaggi,N.; Boldt, G.; Hixon, M.; Kennedy, J.; Tzipori, S.; Janda, K.; Allen, K.

    2007-01-01

    The potential for the use of Clostridial neurotoxins as bioweapons makes the development of small-molecule inhibitors of these deadly toxins a top priority. Recently, screening of a random hydroxamate library identified a small-molecule inhibitor of C. botulinum Neurotoxin Serotype A Light Chain (BoNT/A-LC), 4-chlorocinnamic hydroxamate, a derivative of which has been shown to have in vivo efficacy in mice and no toxicity. We describe the X-ray crystal structures of BoNT/A-LC in complexes with two potent small-molecule inhibitors. The structures of the enzyme with 4-chlorocinnamic hydroxamate or 2,4-dichlorocinnamic hydroxamate bound are compared to the structure of the enzyme complexed with L-arginine hydroxamate, an inhibitor with modest affinity. Taken together, this suite of structures provides surprising insights into the BoNT/A-LC active site, including unexpected conformational flexibility at the S1' site that changes the electrostatic environment of the binding pocket. Information gained from these structures will inform the design and optimization of more effective small-molecule inhibitors of BoNT/A-LC.

  12. Inhibition of class IIb histone deacetylase significantly improves cloning efficiency in mice.

    PubMed

    Ono, Tetsuo; Li, Chong; Mizutani, Eiji; Terashita, Yukari; Yamagata, Kazuo; Wakayama, Teruhiko

    2010-12-01

    Since the first mouse clone was produced by somatic cell nuclear transfer, the success rate of cloning in mice has been extremely low. Some histone deacetylase inhibitors, such as trichostatin A and scriptaid, have improved the full-term development of mouse clones significantly, but the mechanisms allowing for this are unclear. Here, we found that two other specific inhibitors, suberoylanilide hydroxamic acid and oxamflatin, could also reduce the rate of apoptosis in blastocysts, improve the full-term development of cloned mice, and increase establishment of nuclear transfer-generated embryonic stem cell lines significantly without leading to obvious abnormalities. However, another inhibitor, valproic acid, could not improve cloning efficiency. Suberoylanilide hydroxamic acid, oxamflatin, trichostatin A, and scriptaid are inhibitors for classes I and IIa/b histone deacetylase, whereas valproic acid is an inhibitor for classes I and IIa, suggesting that inhibiting class IIb histone deacetylase is an important step for reprogramming mouse cloning efficiency.

  13. Synthesis and characterization of two new hydroxamic acids derivatives and their metal complexes. An investigation on the keto/enol, E/Z and hydroxamate/hydroximate forms

    NASA Astrophysics Data System (ADS)

    Adiguzel, Ekrem; Yilmaz, Fatih; Emirik, Mustafa; Ozil, Musa

    2017-01-01

    2-phenylbenzimidazole-N-acetohydroxamic acid (HL1), 2-phenylbenzimidazole-N-butanohydroxamic acid (HL2) and Ni(II), Cu(II), Zn(II) and Cd(II) metal complexes have been synthesized and characterized by elemental analyses, 1H NMR, 13C NMR, FT-IR spectrometry, LC-MS (ESI+) and thermal analyses. The results of NMR spectra and theoretical calculations showed that the hydroxamic acids were in the keto-E and keto-Z conformations. The elemental analysis and thermal analysis indicated that M:L ratio of the complexes are 1:1 and the spectral analysis confirmed that hydroxamate groups are keto form in the Ni(II) and Zn(II) complexes of 2-phenylbenzimidazole-N-butanohydroxamic acid and enol form in the other complexes.

  14. Adsorption and self-assembly of octyl hydroxamic acid at a fluorite surface as revealed by sum-frequency vibrational spectroscopy.

    PubMed

    Wang, Xuming; Liu, Jin; Miller, Jan D

    2008-09-15

    In the study described here, the surface structure of a self-assembly octyl hydroxamic acid at a calcium fluoride (CaF(2)) surface is evaluated using sum-frequency vibrational spectroscopy (SFVS). Of particular significance are the results that show octyl hydroxamic acid adsorbs at the fluorite surface from octanol solution and has more ordering and molecular conformation than the octyl hydroxamic acid adsorbed from solution. At the fluorite/0.1 M octyl hydroxamic acid octanol solution interface a bilayer-like structure consisting of an octyl hydroxamic acid layer in contact with fluorite and a tilted alcohol layer was observed by SFVS. The alcohol molecules are oriented with respect to the hydroxamic acid monolayer with the OH groups directed towards the bulk alcohol phase and the terminal CH(3) group oriented to face the alkyl chains of the hydroxamic acid monolayer.

  15. Efficient organic monoliths prepared by γ-radiation induced polymerization in the evaluation of histone deacetylase inhibitors by capillary(nano)-high performance liquid chromatography and ion trap mass spectrometry.

    PubMed

    Badaloni, Elena; Barbarino, Marcella; Cabri, Walter; D'Acquarica, Ilaria; Forte, Michela; Gasparrini, Francesco; Giorgi, Fabrizio; Pierini, Marco; Simone, Patrizia; Ursini, Ornella; Villani, Claudio

    2011-06-24

    New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.) and nano (100-75 μm I.D.) fused-silica tubes yielding highly efficient columns for cap(nano)-LC applications. The columns were applied in the complete separation of core (H2A, H2B, H3, and H4) and linker (H1) histones under gradient elution with UV and/or electrospray ionization (ESI) ion trap mass spectrometry (MS) detections. Large selectivity towards H1, H2A-1, H2A-2, H2B, H3-1, H3-2 and H4 histones and complete separation were obtained within 8 min time windows, using fast gradients and very high linear flow velocities, up to 11 mm/s for high throughput applications. The method developed was the basis of a simple and efficient protocol for the evaluation of post-translational modifications (PTMs) of histones from NCI-H460 human non-small-cell lung cancer (NSCLC) and HCT-116 human colorectal carcinoma cells. The study was extended to monitoring the level of histone acetylation after inhibition of Histone DeACetylase (HDAC) enzymes with suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor approved by the FDA for cancer therapy. Attractive features of our cap(nano)-LC/MS approach are the short analysis time, the minute amount of sample required to complete the whole procedure and the stability of the polymethacrylate-based columns. A lab-made software package ClustMass was ad hoc developed and used to elaborate deconvoluted mass spectral data (aligning, averaging, clustering) and calculate the potency of HDAC inhibitors, expressed through a Relative half maximal Inhibitory Concentration parameter, namely R_IC(50) and an averaged acetylation degree. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. A `Clicked' Tetrameric Hydroxamic Acid Glycopeptidomimetic Antagonizes Sugar-Lectin Interactions On The Cellular Level

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Lin; Zang, Yi; Xie, Juan; Li, Jia; Chen, Guo-Rong; He, Xiao-Peng; Tian, He

    2014-07-01

    A tetrameric N-acetyl galactosaminyl (GalNAc) peptidomimetic was constructed by N-acetylation of repeating proline-based hydroxamic acid units, followed by a convergent `click chemistry' coupling. This novel glycopeptidomimetic was determined to effectively antagonize the interaction between a transmembrane hepatic lectin and GalNAc on the cellular level.

  17. Salinomycin Hydroxamic Acids: Synthesis, Structure, and Biological Activity of Polyether Ionophore Hybrids.

    PubMed

    Borgström, Björn; Huang, Xiaoli; Chygorin, Eduard; Oredsson, Stina; Strand, Daniel

    2016-06-09

    The polyether ionophore salinomycin has recently gained attention due to its exceptional ability to selectively reduce the proportion of cancer stem cells within a number of cancer cell lines. Efficient single step strategies for the preparation of hydroxamic acid hybrids of this compound varying in N- and O-alkylation are presented. The parent hydroxamic acid, salinomycin-NHOH, forms both inclusion complexes and well-defined electroneutral complexes with potassium and sodium cations via 1,3-coordination by the hydroxamic acid moiety to the metal ion. A crystal structure of an cationic sodium complex with a noncoordinating anion corroborates this finding and, moreover, reveals a novel type of hydrogen bond network that stabilizes the head-to-tail conformation that encapsulates the cation analogously to the native structure. The hydroxamic acid derivatives display down to single digit micromolar activity against cancer cells but unlike salinomycin selective reduction of ALDH(+) cells, a phenotype associated with cancer stem cells was not observed. Mechanistic implications are discussed.

  18. Antitumor activity of SAHA, a novel histone deacetylase inhibitor, against murine B cell lymphoma A20 cells in vitro and in vivo.

    PubMed

    Yang, Bohan; Yu, Dandan; Liu, Jingwen; Yang, Kunyu; Wu, Gang; Liu, Hongli

    2015-07-01

    Suberoylanilide hydroxamic acid (SAHA; vorinostat), the second generation of histone deacetylase (HDAC) inhibitor, has been approved for the treatment of cutaneous manifestations of cutaneous T cell lymphoma (CTCL). It has also shown its anticancer activity over a large range of other hematological and solid malignancies, but few studies have been reported in B cell lymphoma. In this study, we aimed to investigate the antitumor activity of SAHA on murine B cell lymphoma cell line A20 cells. We treated A20 cells with different concentrations of SAHA. The effect of SAHA on the proliferation of A20 cells was studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay in vitro; the anti-proliferation activity in vivo was evaluated by proliferating cell nuclear antigen (PCNA) of xenograft tumor tissues through immunocytochemical staining. Apoptosis were detected by Hoechst 33258 staining and Annexin V/propidium iodide (PI) double-labeled cytometry in vitro. The effect of SAHA on cell cycle of A20 cells was studied by a propidium iodide method. Autophagic cell death induced by SAHA was confirmed by transmission electron microscopy (TEM). Angiogenesis marker (CD31) was measured by immunocytochemical staining to investigate the anti-angiogenic effect of SAHA. Western blot was used to detect the expression of signaling pathway factors (phospho-AKT, phospho-ERK, AKT, ERK, Nur77, HIF-1α, and VEGF). Our results showed that SAHA inhibited the proliferation of A20 cells in a time- and dose-dependent manner, induced cell apoptosis and G0/G1 phase arrest of cell cycle, promoted autophagic cell death, and suppressed tumor progress in NCI-A20 cells nude mice xenograft model in vivo. SAHA decreased the activation of AKT (phospho-AKT: p-AKT) and ERK1/2 (phospho-ERK: p-ERK) proteins and inhibited the expression of pro-angiogenic factors (VEGF and HIF-1α), downregulated its downstream signaling factor (Nur77), which might be contributed to the antitumor mechanisms

  19. Hydroxamic acid content and toxicity of rye at selected growth stages.

    PubMed

    Rice, Clifford P; Park, Yong Bong; Adam, Frédérick; Abdul-Baki, Aref A; Teasdale, John R

    2005-08-01

    Rye (Secale cereale L.) is an important cover crop that provides many benefits to cropping systems including weed and pest suppression resulting from allelopathic substances. Hydroxamic acids have been identified as allelopathic compounds in rye. This research was conducted to improve the methodology for quantifying hydroxamic acids and to determine the relationship between hydroxamic acid content and phytotoxicity of extracts of rye root and shoot tissue harvested at selected growth stages. Detection limits for an LC/MS-MS method for analysis of hydroxamic acids from crude aqueous extracts were better than have been reported previously. (2R)-2-beta-D-Glucopyranosyloxy-4-hydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA-G), 2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA), benzoxazolin-2(3H)-one (BOA), and the methoxy-substituted form of these compounds, (2R)-2-beta-D-glucopyranosyloxy-4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA glucose), 2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA), and 6-methoxy-benzoxazolin-2(3H)-one (MBOA), were all detected in rye tissue. DIBOA and BOA were prevalent in shoot tissue, whereas the methoxy-substituted compounds, DIMBOA glucose and MBOA, were prevalent in root tissue. Total hydroxamic acid concentration in rye tissue generally declined with age. Aqueous crude extracts of rye shoot tissue were more toxic than extracts of root tissue to lettuce (Lactuca sativa L.) and tomato (Lycopersicon esculentum Mill.) root length. Extracts of rye seedlings (Feekes growth stage 2) were most phytotoxic, but there was no pattern to the phytotoxicity of extracts of rye sampled at growth stages 4 to 10.5.4, and no correlation of hydroxamic acid content and phytotoxicity (I50 values). Analysis of dose-response model slope coefficients indicated a lack of parallelism among models for rye extracts from different growth stages, suggesting that phytotoxicity may be attributed to compounds with different modes of action at

  20. Therapeutic potential of sulindac hydroxamic acid against human pancreatic and colonic cancer cells.

    PubMed

    Fogli, Stefano; Banti, Irene; Stefanelli, Fabio; Picchianti, Luca; Digiacomo, Maria; Macchia, Marco; Breschi, Maria Cristina; Lapucci, Annalina

    2010-11-01

    The non-steroidal anti-inflammatory drug (NSAID) sulindac exhibits cyclooxygenase (COX)-dependent and COX-independent chemopreventive properties in human cancer. The present study was aimed at investigating whether the hydroxamic acid substitution for the carboxylic acid group could enhance the in vitro antitumor and antiangiogenic activities of sulindac. Characterization tools used on this study included analyses of cell viability, caspase 3/7 induction, DNA fragmentation, and gene expression. Our findings demonstrate that the newly synthesized hydroxamic acid derivative of sulindac and its sulfone and sulfide metabolites were characterized by a good anticancer activity on human pancreatic and colon cancer cells, both in terms of potency (IC(50) mean values from 6 ± 1.1 μM to 64 ± 1.1 μM) and efficacy (E(max) of ∼100%). Hydroxamic acid derivatives trigger a higher degree of apoptosis than carboxylic acid counterparts, increase bax/bcl-2 expression ratio and induce caspase 3/7 activation. Most notably, these compounds significantly inhibit proangiogenic growth factor-stimulated proliferation of vascular endothelial cell (HUVEC) at sub-micromolar concentrations. Our data also provide evidence that the COX-active metabolite of sulindac hydroxamic acid were the most active of the series and selective inhibition of COX-1 but not COX-2 can mimic its effects, suggesting that COX inhibition could only play a partial role in the mechanism of compound action. In conclusion, these data demonstrate that substitution of the carboxylic acid group with the hydroxamic acid moiety enhances in vitro antiproliferative, proapoptotic and antiangiogenic properties of sulindac, therefore increasing the therapeutic potential of this drug. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  1. Simultaneous determination of decitabine and vorinostat (Suberoylanalide hydroxamic acid, SAHA) by liquid chromatography tandem mass spectrometry for clinical studies.

    PubMed

    Patel, Katan; Guichard, Sylvie M; Jodrell, Duncan I

    2008-02-15

    A reverse-phase high-performance liquid chromatography method with electrospray ionization and detection by tandem mass spectrometry is described for the simultaneous quantitative determination of decitabine (5-aza-2'-deoxycytidine) and vorinostat (Suberoylanalide hydroxamic acid, SAHA) in human plasma. The method involves a simple acetonitrile precipitation step and centrifugation followed by injection of the supernatant onto a C18 150mmx2.1mm I.D., 3microm HPLC column at 36 degrees C. Separation of decitabine, SAHA and their respective internal standards was achieved with a gradient elution and detection was via the mass spectrometer operated in selected reaction monitoring mode. The method was within the defined validation parameters for linearity, repeatability, reproducibility and stability. The limit of detection was determined as 1.0 and 0.125ngml(-1) and lower limits of quantitation were 10 and 1ngml(-1) for decitabine and SAHA, respectively. Effects of sample preparation on stability were also evaluated in human plasma. For clinical sample handling tetrahydrouridine, an inhibitor of cytidine deaminase was found to help prevent decitabine degradation. The method is currently being used in clinical pharmacokinetic studies for the evaluation of decitabine and SAHA combination therapies.

  2. Syntheses and Biological Evaluations of Highly Functionalized Hydroxamate Containing and N-Methylthio Monobactams as Anti-Tuberculosis and β-Lactamase Inhibitory Agents

    PubMed Central

    Majewski, Mark W.; Watson, Kyle D.; Cho, Sanghyun; Miller, Patricia A.; Franzblau, Scott G.; Miller, Marvin J.

    2015-01-01

    Both the resurgence of tuberculosis (TB) and antibiotic resistance continue to threaten modern healthcare and new means of combating pathogenic bacterial infections are needed. The syntheses of monobactams possessing hydroxamate and N-methylthio functionality are described, as well as their anti-TB, in vitro β-lactamase inhibitory, and general antimicrobial evaluations. A number of compounds exhibited significant anti-TB and β-lactamase inhibitory activity, with MIC values in the range of 25 to < 0.19 μM against Mycobacteria tuberculosis (M.tb), and Ki values in the range of 25–0.03 μM against purified NDM-1 and VIM-1 lystate metallo β-lactamases. This work suggests that these scaffolds may serve as promising leads in developing new antibiotics and/or β-lactamase inhibitors. PMID:26918106

  3. Water-Stable, Hydroxamate Anchors for Functionalization of TiO2 Surfaces with Ultrafast Interfacial Electron Transfer

    SciTech Connect

    McNamara, W.R.; Milot, R.L.; Song, H.; Snoeberger III, R.C.; Batista, Victor S.; Schmuttenmaer, C.A.; Brudvig, Gary W; Crabtree, Robert H

    2010-01-01

    A novel class of derivatized hydroxamic acid linkages for robust sensitization of TiO{sub 2} nanoparticles (NPs) under various aqueous conditions is described. The stability of linkages bound to metal oxides under various conditions is important in developing photocatalytic cells which incorporate transition metal complexes for solar energy conversion. In order to compare the standard carboxylate anchor to hydroxamates, two organic dyes differing only in anchoring groups were synthesized and attached to TiO{sub 2} NPs. At acidic, basic, and close to neutral pH, hydroxamic acid linkages resist detachment compared to the labile carboxylic acids. THz spectroscopy was used to compare ultrafast interfacial electron transfer (IET) into the conduction band of TiO{sub 2} for both linkages and found similar IET characteristics. Observable electron injection and stronger binding suggest that hydroxamates are a suitable class of anchors for designing water stable molecules for functionalizing TiO{sub 2}.

  4. Visual and fluorogenic detection of a nerve agent simulant via a Lossen rearrangement of rhodamine-hydroxamate.

    PubMed

    Han, Shoufa; Xue, Zhongwei; Wang, Zhen; Wen, Ting Bin

    2010-11-28

    A visual and fluorogenic detection method for a nerve agent simulant was developed based on a Lossen rearrangement of rhodamine-hydroxamate, in the presence of diethyl chlorophosphate, under alkaline conditions.

  5. 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.

  6. Curcumin and hydroxamate-derivative (PCI-34058) interfere with histone deacetylase I catalytic core Asp-His charge relay system: atomistic simulation studies.

    PubMed

    Omotuyi, I O; Abiodun, M O; Komolafe, K; Ejelonu, O C; Olusanya, O

    2015-05-01

    Histone deacetylases (HDACs) are representative targets for the natural and synthetic chemicals used to transform cells to confer antitumor properties. In the current study, curcumin and hydroxamate-derivative PCI-34058-bound HDAC1 were subjected to atomistic simulation. The results support the view that fitting of curcumin and PCI-34058 within the HDAC1 pocket depends on extensive interactions between the aromatic moieties of the inhibitors and the extensive network of aromatic amino acid side chains lining the pocket of HDAC1. The interaction forces a local perturbation of the coiled structures connecting the pocket residues resulting in ligand-induced tightening of the pocket. In addition to the competitive occupancy of the histone-acetyl-lysine binding pocket by the inhibitors, interference with the in-pocket aspartate-histidine (ASP-HIS) charge relay system was also observed in inhibitor-bound HDAC1 systems. In conclusion, curcumin and PCI-34058-mediated ligand-dependent HDAC1 tunnel closure interferes negatively with the ASP-HIS charge relay system in HDAC1. Future design of HDAC inhibitors may benefit from optimizing competitive interaction with the ligand site and interference with the charge relay system.

  7. Synthesis and biological evaluation of lovastatin-derived aliphatic hydroxamates that induce reactive oxygen species.

    PubMed

    Lin, Ruo-Kai; Lin, Yuh-Feng; Hsu, Ming-Jen; Hsieh, Chang-Lin; Wang, Chen-Yu; Huang, Chih-Chiang; Huang, Wei-Jan

    2016-11-15

    Some hydroxamate compounds induce cancer cell death by intracellular reactive oxygen species (ROS). This study introduced the hydroxamate core into lovastatin, a fungus metabolite clinically used for the treatment of hypercholesterolemia. The resulting compounds were evaluated for the activity for inducing ROS production. Most compounds exhibited higher activity than original lovastatin. Of these compounds, compound 3c had the most potent activity. Test of cytotoxicity in a panel of human cancer cell lines indicated compound 3c had activities superior to cisplatin in prostate cancer PC-3 cells and breast cancer T47D cells. In contrast, it in amounts up to 40μM had a much lower cytotoxic effect on normal human IMR-90 cells. Further profiling of cell cycle progression, cell apoptosis, and DNA damage activated checkpoint signaling pathway revealed the important role of compound 3c-mediated cytotoxicity in ROS generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Combination of the novel histone deacetylase inhibitor YCW1 and radiation induces autophagic cell death through the downregulation of BNIP3 in triple-negative breast cancer cells in vitro and in an orthotopic mouse model.

    PubMed

    Chiu, Hui-Wen; Yeh, Ya-Ling; Wang, Yi-Ching; Huang, Wei-Jan; Ho, Sheng-Yow; Lin, Pinpin; Wang, Ying-Jan

    2016-06-10

    Triple-negative breast cancer (TNBC) is the most aggressive and invasive of the breast cancer subtypes. TNBC is a challenging disease that lacks targets for treatment. Histone deacetylase inhibitors (HDACi) are a group of targeted anticancer agents that enhance radiosensitivity. Bcl-2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) is a member of the Bcl-2 subfamily. BNIP3 is not found in normal breast tissue but is up-regulated in breast cancer. In the present study, we investigated the anti-cancer effects of a newly developed HDACi, YCW1, combined with ionizing radiation (IR) in TNBC in vitro and in an orthotopic mouse model. Furthermore, we examined the relationship between autophagy and BNIP3. Trypan blue exclusion was used to investigate the viability of 4 T1 (a mouse TNBC cell line) and MDA-MB-231 cells (a human TNBC cell line) following combined YCW1 and IR treatment. Flow cytometry was used to determine apoptosis and autophagy. The expression levels of BNIP3, endoplasmic reticulum (ER) stress- and autophagic-related proteins were measured using western blot analysis. An orthotopic mouse model was used to investigate the in vivo effects of YCW1 and IR alone and in combination. Tumor volumes were monitored using a bioluminescence-based IVIS Imaging System 200. We found that YCW1 significantly enhanced toxicity in 4 T1 cells compared with suberoylanilide hydroxamic acid (SAHA), which was the first HDACi approved by the Food and Drug Administration for clinical use in cancer patients. The combined treatment of YCW1 and IR enhanced cytotoxicity by inducing ER stress and increasing autophagy induction. Additionally, the combined treatment caused autophagic flux and autophagic cell death. Furthermore, the expression level of BNIP3 was significantly decreased in cells following combined treatment. The downregulation of BNIP3 led to a significant increase in autophagy and cytotoxicity. The combined anti-tumor effects of YCW1 and IR were also observed

  9. Hydroxamate siderophore-promoted reactions between iron(II) and nitroaromatic groundwater contaminants

    NASA Astrophysics Data System (ADS)

    Kim, Dongwook; Duckworth, Owen W.; Strathmann, Timothy J.

    2009-03-01

    Recent studies show that ferrous iron (Fe II), which is often abundant in anaerobic soil and groundwater, is capable of abiotically reducing many subsurface contaminants. However, studies also demonstrate that Fe II redox reactivity in geochemical systems is heavily dependent upon metal speciation. This contribution examines the influence of hydroxamate ligands, including the trihydroxamate siderophore desferrioxamine B (DFOB), on Fe II reactions with nitroaromatic groundwater contaminants (NACs). Experimental results demonstrate that ring-substituted NACs are reduced to the corresponding aniline products in aqueous solutions containing Fe II complexes with DFOB and two monohydroxamate ligands (acetohydroxamic acid and salicylhydroxamic acid). Reaction rates are heavily dependent upon solution conditions and the identities of both the Fe II-complexing hydroxamate ligand and the target NAC. Trends in the observed pseudo-first-order rate constants for reduction of 4-chloronitrobenzene ( kobs, s -1) are quantitatively linked to the formation of Fe II species with standard one-electron reduction potentials, EH0 (Fe III/Fe II), below -0.3 V. Linear free energy relationships correlate reaction rates with the EH0 (Fe III/Fe II) values of different electron-donating Fe II complexes and with the apparent one-electron reduction potentials of different electron-accepting NACs, EH1'(ArNO 2). Experiments describing a redox auto-decomposition mechanism for Fe II-DFOB complexes that occurs at neutral pH and has implications for the stability of hydroxamate siderophores in anaerobic environments are also presented. Results from this study indicate that hydroxamates and other Fe III-stabilizing organic ligands can form highly redox-active Fe II complexes that may contribute to the natural attenuation and remediation of subsurface contaminants.

  10. Hydroxamate-based colorimetric method for direct screening of transglutaminase-producing bacteria.

    PubMed

    Bourneow, Chaiwut; Benjakul, Soottawat; H-Kittikun, Aran

    2012-05-01

    Microbial transglutaminase (MTGase) is a commercial enzyme that has been applied to many protein containing foods to improve their textural property. The screening of MTGase-producing microorganisms from various sources might lead to the discovery of a new MTGase with different characteristics. This report demonstrates the use of a direct detection method for MTGase-producing bacteria grown on an agar plate by filter paper disc (FPD) assay. The principle of the assay is the formation of a red burgundy color by the hydroxamate-ferric complex. The color developed intensity was linearly correlated by the concentration of hydroxamic acid in the range of 0.1-0.8 μM and was visually scored at 4 levels: 0, 1, 2 and 3. Streptoverticillium mobaraense DSM 40847, a positive MTGase-producer, was chosen for the verification and improving of the proposed method. The colonies grown on the nutrient agar plate at 37°C for 24 h were covered with FPDs and 30 μl of substrates (CBZ-Gln-Gly and hydroxylamine). After incubation, 10 μl of the ferric-TCA-HCl solution was placed on the FPD. The optimal time taken to catalyze the formation of CBZ-Gln-Gly-hydroxamic acid by the MTGase and the time taken for the hydroxamate-ferric complex to form color were 180 and 60 min, respectively. Using this assay, 30 of 189 colonies isolated from wastewater and floating-floc samples showed MTGase-positive colonies which were well correlated to the quantitative screening of MTGase activity (R(2) = 0.9758). The results revealed that the FPD assay could be used for the qualitative screening of MTGase-producing bacteria.

  11. Growth of Actinobacillus pleuropneumoniae is promoted by exogenous hydroxamate and catechol siderophores.

    PubMed

    Diarra, M S; Dolence, J A; Dolence, E K; Darwish, I; Miller, M J; Malouin, F; Jacques, M

    1996-03-01

    Siderophores bind ferric ions and are involved in receptor-specific iron transport into bacteria. Six types of siderophores were tested against strains representing the 12 different serotypes of Actinobacillus pleuropneumoniae. Ferrichrome and bis-catechol-based siderophores showed strong growth-promoting activities for A. pleuropneumoniae in a disk diffusion assay. Most strains of A. pleuropneumoniae tested were able to use ferrichrome (21 of 22 or 95%), ferrichrome A (20 of 22 or 90%), and lysine-based bis-catechol (20 of 22 or 90%), while growth of 36% (8 of 22) was promoted by a synthetic hydroxamate, N5-acetyl-N5-hydroxy-L-ornithine tripeptide. A. pleuropneumoniae serotype 1 (strain FMV 87-682) and serotype 5 (strain 2245) exhibited a distinct yellow halo around colonies on Chrome Azurol S agar plates, suggesting that both strains can produce an iron chelator (siderophore) in response to iron stress. The siderophore was found to be neither a phenolate nor a hydroxamate by the chemical tests of Arnow and Csaky, respectively. This is the first report demonstrating the production of an iron chelator and the use of exogenous siderophores by A. pleuropneumoniae. A spermidine-based bis-catechol siderophore conjugated to a carbacephalosporin was shown to inhibit growth of A. pleuropneumoniae. A siderophore-antibiotic-resistant strain was isolated and shown to have lost the ability to use ferrichrome, synthetic hydroxamate, or catechol-based siderophores when grown under conditions of iron restriction. This observation indicated that a common iron uptake pathway, or a common intermediate, for hydroxamate- and catechol-based siderophores may exist in A. pleuropneumoniae.

  12. A novel strategy for designing specific gelatinase A inhibitors: potential use to control tumor progression.

    PubMed

    Augé, Franck; Hornebeck, William; Laronze, Jean-Yves

    2004-03-01

    Matrix metalloproteases (MMPs) are zinc endopeptidases deeply implicated in tumor progression. MMP inhibitors are attractive potential anti-cancer agent. Unfortunately, until now, clinical trials remain disappointing, that could be the result of a lack of selectivity. We propose second generation selective MMPs, directed toward gelatinase A (MMP-2), based on a non-hydroxamate Zn-ligand grafted on the galardin (ilomastat) skeleton.

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

    PubMed Central

    2015-01-01

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

  14. Synthesis and biological evaluation of triazol-4-ylphenyl-bearing histone deacetylase inhibitors as anticancer agents.

    PubMed

    He, Rong; Chen, Yufeng; Chen, Yihua; Ougolkov, Andrei V; Zhang, Jin-San; Savoy, Doris N; Billadeau, Daniel D; Kozikowski, Alan P

    2010-02-11

    Our triazole-based histone deacetylase inhibitor (HDACI), octanedioic acid hydroxyamide[3-(1-phenyl-1H-[1,2,3]triazol-4-yl)phenyl]amide (4a), suppresses pancreatic cancer cell growth in vitro with the lowest IC(50) value of 20 nM against MiaPaca-2 cell. In this study, we continued our efforts to develop triazol-4-ylphenyl bearing hydroxamate analogues by embellishing the terminal phenyl ring of 4a with different substituents. The isoform inhibitory profile of these hydroxamate analogues was similar to those of 4a. All of these triazol-4-ylphenyl bearing hydroxamates are pan-HDACIs like SAHA. Moreover, compounds 4h and 11a were found to be very effective inhibitors of cancer cell growth in the HupT3 (IC(50) = 50 nM) and MiaPaca-2 (IC(50) = 40 nM) cancer cell lines, respectively. Compound 4a was found to reactivate the expression of CDK inhibitor proteins and to suppress pancreatic cancer cell growth in vivo. Taken together, these data further support the value of the triazol-4-ylphenyl bearing hydroxamates in identifying potential pancreatic cancer therapies.

  15. A new approach to cyclic hydroxamic acids: Intramolecular cyclization of N-benzyloxy carbamates with carbon nucleophiles

    PubMed Central

    Liu, Yuan; Jacobs, Hollie K.

    2011-01-01

    N-Alkyl-N-benzyloxy carbamates, 2, undergo facile intramolecular cyclization with a variety of carbon nucleophiles to give functionalized 5- and 6-membered protected cyclic hydroxamic acids, 3, in good to excellent yields. This method can be extended to prepare seven-membered cyclic hydroxamic acids in moderate yields. The sulfone intermediates 3 from this study can be alkylated while the corresponding phosphonates have been shown to undergo HWE reaction. The α,β-unsaturated synthon, 8, prepared by thermal elimination of sulfoxide 3m, undergoes Michael addition with secondary amines. The usefulness of this approach to prepare polydentate chelators has been demonstrated by the synthesis of bis cyclic hydroxamic acids 12, 14, and 15. PMID:21499514

  16. A novel hydroxamic acid-containing antibiotic produced by a Saharan soil-living Streptomyces strain.

    PubMed

    Yekkour, A; Meklat, A; Bijani, C; Toumatia, O; Errakhi, R; Lebrihi, A; Mathieu, F; Zitouni, A; Sabaou, N

    2015-06-01

    During screening for potentially antimicrobial actinobacteria, a highly antagonistic strain, designated WAB9, was isolated from a Saharan soil of Algeria. A polyphasic approach characterized the strain taxonomically as a member of the genus Streptomyces. The strain WAB9 exhibited a broad spectrum of antimicrobial activity toward various multidrug-resistant micro-organisms. A PCR-based assay of genomic potential for producing bioactive metabolites revealed the presence of PKS-II gene. After 6 days of strain fermentation, one bioactive compound was extracted from the remaining aqueous phase and then purified by HPLC. The chemical structure of the compound was determined by spectroscopic (UV-visible, and (1)H and (13)C NMR) and spectrometric analysis. The compound was identified to be 2-amino-N-(2-amino-3-phenylpropanoyl)-N-hydroxy-3-phenylpropanamide, a novel hydroxamic acid-containing molecule. The pure molecule showed appreciable minimum inhibitory concentration values against a selection of drug-resistant bacteria, filamentous fungi and yeasts. Significance and impact of the study: This study presents the isolation of a Streptomyces strain, named WAB9, from a Saharan soil in Algeria. This strain was found to produce a new hydroxamic acid-containing molecule with interesting antimicrobial activities towards various multidrug-resistant micro-organisms. Although hydroxamic acid-containing molecules are known to exhibit low toxicities in general, only real evaluations of the toxicity levels could decide on the applications for which this new molecule is potentially most appropriate. Thus, this article provides a new framework of research.

  17. Catalytic Kinetic Resolution of Saturated N-Heterocycles by Enantioselective Amidation with Chiral Hydroxamic Acids.

    PubMed

    Kreituss, Imants; Bode, Jeffrey W

    2016-12-20

    The preparation of enantioenriched chiral compounds by kinetic resolution dates back to the laboratories of Louis Pasteur in the middle of the 19th century. Unlike asymmetric synthesis, this process can always deliver enantiopure material (ee > 99%) if the reactions are allowed to proceed to sufficient conversion and the selectivity of the process is not unity (s > 1). One of the most appealing and practical variants is acylative kinetic resolution, which affords easily separable reaction products, and several highly efficient enzymatic and small molecule catalysts are available. Unfortunately, this method is applicable to limited substrate classes such as alcohols and primary benzylamines. This Account focuses on our work in catalytic acylative kinetic resolution of saturated N-heterocycles, a class of molecules that has been notoriously difficult to access via asymmetric synthesis. We document the development of hydroxamic acids as suitable catalysts for enantioselective acylation of amines through relay catalysis. Alongside catalyst optimization and reaction development, we present mechanistic studies and theoretical calculation accounting for the origins of selectivity and revealing the concerted nature of many amide-bond forming reactions. Immobilization of the hydroxamic acid to form a polymer supported reagent allows simplification of the experimental setup, improvement in product purification, and extension of the substrate scope. The kinetic resolutions are operationally straight forward: reactions proceed at room temperature and open to air conditions, without generation of difficult-to-remove side products. This was utilized to achieve decagram scale resolution of antimalarial drug mefloquine to prepare more than 50 g of (+)-erythro-meflqouine (er > 99:1) from the racemate. The immobilized quasienantiomeric acyl hydroxamic acid reagents were also exploited for a rare practical implementation of parallel kinetic resolution that affords both enantiomers of

  18. The variable hydroxamic acid siderophore metabolome of the marine actinomycete Salinispora tropica CNB-440.

    PubMed

    Ejje, Najwa; Soe, Cho Zin; Gu, Jiesi; Codd, Rachel

    2013-11-01

    The recently sequenced genome of the marine actinomycete Salinispora tropica CNB-440 revealed a high frequency of gene clusters which code for the biosynthesis of known and novel secondary metabolites. Of these metabolites, bioinformatics analysis predicted that S. tropica CNB-440 could potentially biosynthesize, as high affinity Fe(iii) ligands, siderophores from the hydroxamic acid desferrioxamine class (sid1 gene cluster) and the phenolate-thia(oxa)zoli(di)ne class (sid2 and sid4 gene clusters). In this work, we have used Ni(ii)-based immobilized metal ion affinity chromatography (IMAC) to pre-fractionate the hydroxamic acid siderophore metabolome of S. tropica CNB-440 from the secondary metabolome, to reveal low abundance siderophores. LC-MS measurements and electronic absorption spectra from purified extracts incubated with exogenous Fe(iii) revealed eight siderophores from the desferrioxamine class (DFOA2, DFOA1a, DFOA1b, DFOB, DFON, DFOD2, DFOE, DFOD1), which included two constitutional isomers (DFOA1a, DFOA1b), and one new siderophore (DFON), the latter which would require assembly from a combination of 1,5-diaminopentane and 1,6-diaminohexane as diamine substrates. Three additional species (m/zobs 496.14, 792.34 and 804.34) with electronic absorption spectra characteristic of complexes formed between Fe(iii) and hydroxamic acid-type siderophores were evident under some conditions. The signal at m/zobs 792.34 eluted in the hydrophobic region of the reverse-phase LC and correlated with a DFOD1 analogue with a C-terminal branched chain fatty acid ([M + K(+)](+)m/zcalc 792.35), which has been previously identified from marine sediment dwelling Micrococcus luteus KLE1011. The S. tropica CNB-440 hydroxamic acid siderophore metabolome was modulated by culture conditions (pH 7, 22 °C; pH 7, 28 °C; pH 9, 28 °C) designed to simulate the variable marine environment. An increase in temperature at constant pH value showed increased levels of DFOA2 and DFOA1, and

  19. OleD Loki as a Catalyst for Tertiary Amine and Hydroxamate Glycosylation.

    PubMed

    Hughes, Ryan R; Shaaban, Khaled A; Zhang, Jianjun; Cao, Hongnan; Phillips, George N; Thorson, Jon S

    2017-02-16

    We describe the ability of an engineered glycosyltransferase (OleD Loki) to catalyze the N-glycosylation of tertiary-amine-containing drugs and trichostatin hydroxamate glycosyl ester formation. As such, this study highlights the first bacterial model catalyst for tertiary-amine N-glycosylation and further expands the substrate scope and synthetic potential of engineered OleDs. In addition, this work could open the door to the discovery of similar capabilities among other permissive bacterial glycosyltransferases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Efficient Route to Highly Water-Soluble Aromatic Cyclic Hydroxamic Acid Ligands

    SciTech Connect

    Seitz, Michael; Raymond, Kenneth N.

    2008-02-06

    2-Hydroxyisoquinolin-1-one (1,2-HOIQO) is a new member of the important class of aromatic cyclic hydroxamic acid ligands which are widely used in metal sequestering applications and metal chelating therapy. The first general approach for the introduction of substituents at the aromatic ring of the chelating moiety is presented. As a useful derivative, the highly water-soluble sulfonic acid has been synthesized by an efficient route that allows general access to 1,2-HOQIO 3-carboxlic acid amides, which are the most relevant for applications.

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

    PubMed

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

    2007-05-03

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

  2. What Makes Hydroxamate a Promising Anchoring Group in Dye-Sensitized Solar Cells? Insights from Theoretical Investigation.

    PubMed

    Li, Wei; Rego, Luis G C; Bai, Fu-Quan; Wang, Jian; Jia, Ran; Xie, Li-Ming; Zhang, Hong-Xing

    2014-11-20

    We report, from a theoretical point of view, the first comparative study between the highly water-stable hydroxamate and the widely used carboxylate, in addition to the robust phosphate anchors. Theoretical calculations reveal that hydroxamate would be better for photoabsorption. A quantum dynamics description of the interfacial electron transfer (IET), including the underlying nuclear motion effect, is presented. We find that both hydroxamate and carboxylate would have efficient IET character; for phosphate the injection time is significantly longer (several hundred femtoseconds). We also verified that the symmetry of the geometry of the anchoring group plays important roles in the electronic charge delocalization. We conclude that hydroxamate can be a promising anchoring group, as compared to carboxylate and phosphate, due to its better photoabsorption and comparable IET time scale as well as the experimental advantage of water stability. We expect the implications of these findings to be relevant for the design of more efficient anchoring groups for dye-sensitized solar cell (DSSC) application.

  3. From α-nucleophiles to functionalized aggregates: exploring the reactivity of hydroxamate ion towards esterolytic reactions in micelles.

    PubMed

    Singh, Namrata; Karpichev, Yevgen; Sharma, Rahul; Gupta, Bhanushree; Sahu, Arvind K; Satnami, Manmohan L; Ghosh, Kallol K

    2015-03-14

    Owing to the rising threats of neurotoxic organophosphosphorus compounds, facile and efficient decontamination systems are required. Since the last few decades, the search for promising α-nucleophiles for straightforward and eco-friendly decontamination reactions using α-nucleophiles has been considerably boosted up. Among these, hydroxamic acids have been widely studied due to their potential α-nucleophilicity towards carbon and phosphorus based esters. This account summarizes our research on α-nucleophilicity of hydroxamate ions in water and micelles towards esterolytic reactions. Efforts of our group in the last few years have been collectively judged and compared with the crucial findings of researchers in the relevant field. The present article sheds light on the rich chemistry of the hydroxamate ion as a perfect candidate to degrade organophosphorus esters (i.e. nerve agents, pesticides and their simulants) in water, in micelles of conventional surfactants, and in functionalized micelles. The current report also provides an insight into the possible nature and mechanisms of these reactions. A brief account of the biological activities of hydroxamic acids that have recently spurred research in medicine against some fatal diseases has been included.

  4. Betulinic acid derived hydroxamates and betulin derived carbamates are interesting scaffolds for the synthesis of novel cytotoxic compounds.

    PubMed

    Wiemann, Jana; Heller, Lucie; Perl, Vincent; Kluge, Ralph; Ströhl, Dieter; Csuk, René

    2015-12-01

    The betulinic acid-derived hydroxamates 5-18, the amides 19-24, and betulin-derived bis-carbamates 25-28 as well as the carbamates 31-40 and 44-48 were prepared and evaluated for their antiproliferative activity in a photometric sulforhodamine B (SRB) assay against several human cancer cell lines and nonmalignant mouse fibroblasts (NIH 3T3). While for 3-O-acetyl hydroxamic acid 5 EC50 values as low as EC50 = 1.3 μM were found, N,O-bis-alkyl substituted hydroxamates showed lowered cytotoxicity (EC50 = 16-20 μM). In general, hydroxamic acid derivatives showed only reduced selectivity for tumor cells, except for allyl substituted compound 13 (EC50 = 5.9 μM for A2780 human ovarian carcinoma cells and EC50 > 30 μM for nonmalignant mouse fibroblasts). The cytotoxicity of betulinic acid derived amides 19-24 and of betulin derived bis-carbamates 25-28 was low, except for N-ethyl substituted 25. Hexyl substituted 39 showed EC50 = 5.6 μM (518A2 cells) while for mouse fibroblasts EC50 > 30 was determined.

  5. Iron-Binding Compounds from Agrobacterium spp.: Biological Control Strain Agrobacterium rhizogenes K84 Produces a Hydroxamate Siderophore

    PubMed Central

    Penyalver, Ramón; Oger, Philippe; López, María M.; Farrand, Stephen K.

    2001-01-01

    Iron-binding compounds were produced in various amounts in response to iron starvation by a collection of Agrobacterium strains belonging to the species A. tumefaciens, A. rhizogenes, and A. vitis. The crown gall biocontrol agent A. rhizogenes strain K84 produced a hydroxamate iron chelator in large amounts. Production of this compound, and also of a previously described antibiotic-like substance called ALS84, occurred only in cultures of strain K84 grown in iron-deficient medium. Similarly, sensitivity to ALS84 was expressed only when susceptible cells were tested in low-iron media. Five independent Tn5-induced mutants of strain K84 affected in the production of the hydroxamate iron chelator showed a similar reduction in the production of ALS84. One of these mutants, M8-10, was completely deficient in the production of both agents and grew poorly compared to the wild type under iron-limiting conditions. Thus, the hydroxamate compound has siderophore activity. A 9.1-kb fragment of chromosomal DNA containing the Tn5 insertion from this mutant was cloned and marker exchanged into wild-type strain K84. The homogenote lost the ability to produce the hydroxamate siderophore and also ALS84. A cosmid clone was isolated from a genomic library of strain K84 that restored to strain M8-10 the ability to produce of the siderophore and ALS84, as well as growth in iron-deficient medium. This cosmid clone contained the region in which Tn5 was located in the mutant. Sequence analysis showed that the Tn5 insert in this mutant was located in an open reading frame coding for a protein that has similarity to those of the gramicidin S synthetase repeat superfamily. Some such proteins are required for synthesis of hydroxamate siderophores by other bacteria. Southern analysis revealed that the biosynthetic gene from strain K84 is present only in isolates of A. rhizogenes that produce hydroxamate-type compounds under low-iron conditions. Based on physiological and genetic analyses showing

  6. Copper (II) ion adsorption from aqueous solution onto fatty hydroxamic acid - Immobilized zeolyte

    NASA Astrophysics Data System (ADS)

    Muhsinun, Sugita, Purwantiningsih; Purwaningsih, Henny

    2017-01-01

    Separation of Cu (II) ion from a mixture containing Zn (II) ion was conducted by solid-liquid extraction method through column chromatography. The column was filled with FHA-ZEO resin. This resin is the result of immobilized fatty hydroxamic acid (FHA) into activated natural zeolite (ZEO) involving as solid phase. Parameters becoming variable were resin mass to concentration ratio and pH of Cu (II) ion solution. The research result shows that optimum condition of Cu (II) ion adsorption was 1 gram resin mass FHA-ZEO to ion Cu (II) solution concentration of 100 ppm with pH value of 5. This Cu (II) ion separation from its mixture containing Zn (II) ion gives Cu(II) ion adsorption capacity of 162.39 mg/g FHA-ZEO in that optimum condition, 4 times higher than Zn (II) ion adsorption with Cu (II) ion recovery of 93,88%.

  7. Sorption of Pb(ll) by poly(hydroxamic acid) grafted oil palm empty fruit bunch.

    PubMed

    Haron, M J; Tiansin, M; Ibrahim, N A; Kassim, A; Wan Yunus, W M Z; Talebi, S M

    2011-01-01

    This paper describes the sorption of Pb(ll) from aqueous solution. Oil palm empty fruit bunch (OPEFB) fiber was first grafted with poly(methylacrylate) and then treated with hydroxylammonium chloride in alkaline medium to produce hydroxamic acid (PHA) grafted OPEFB. Sorption of Pb(ll) by PHA-OPEFB was maximum at pH 5. The sorption followed the Langmuir model with maximum capacityof 125.0 mg g-1 at 25 degrees C. The sorption process was exothermic, as shown by the negative value of enthalpy change, Delta H0. The free energy change (DeltaG0) for the sorption was negative, showing that the sorption process was spontaneous. A kinetic study showed that the Pb(ll) sorption followed a second order kinetic model.

  8. Hydroxamic acid derivatives: a promising scaffold for rational compound optimization in Chagas disease.

    PubMed

    de Menezes, Dayanne da Rocha; Calvet, Claudia Magalhães; Rodrigues, Giseli Capaci; de Souza Pereira, Mirian Claudia; Almeida, Igor Rodrigues; de Aguiar, Alcino Palermo; Supuran, Claudiu T; Vermelho, Alane Beatriz

    2016-12-01

    This work describes the antitrypanocidal activity of two hydroxamic acid derivatives containing o-ethoxy (HAD1) and p-ethoxy (HAD2) as substituent in the aromatic ring linked to the isoxazoline ring. HAD1 and HAD2 induced a significant reduction in the number of intracellular parasites and consequently showed activity on the multiplication of the parasite. Treatment of cardiomyocytes and macrophages with the compounds revealed no significant loss in cell viability. Ultrastructural alterations after treatment of cardiomyocytes or macrophages infected by Trypanosoma cruzi with the IC50 value of HAD1 revealed alterations to amastigotes, showing initial damage seen as swelling of the kinetoplast. This gave a good indication of the ability of the drug to permeate through the host cell membrane as well as its selectivity to the parasite target. Both compounds HAD1 and 2 were able to reduce the cysteine peptidases and decrease the activity of metallopeptidases.

  9. A high-throughput screening strategy for nitrile-hydrolyzing enzymes based on ferric hydroxamate spectrophotometry.

    PubMed

    He, Yu-Cai; Ma, Cui-Luan; Xu, Jian-He; Zhou, Li

    2011-02-01

    Nitrile-hydrolyzing enzymes (nitrilase or nitrile hydratase/amidase) have been widely used in the pharmaceutical industry for the production of carboxylic acids and their derivatives, and it is important to build a method for screening for nitrile-hydrolyzing enzymes. In this paper, a simple, rapid, and high-throughput screening method based on the ferric hydroxamate spectrophotometry has been proposed. To validate the accuracy of this screening strategy, the nitrilases from Rhodococcus erythropolis CGMCC 1.2362 and Alcaligenes sp. ECU0401 were used for evaluating the method. As a result, the accuracy for assaying aliphatic and aromatic carboxylic acids was as high as the HPLC-based method. Therefore, the method may be potentially used in the selection of microorganisms or engineered proteins with nitrile-hydrolyzing enzymes.

  10. Design, synthesis and biological evaluation of novel hydroxamic acids bearing artemisinin skeleton.

    PubMed

    Ha, Vu Thi; Kien, Vu Tuan; Binh, Le Huy; Tien, Vu Dinh; My, Nguyen Thi Thuy; Nam, Nguyen Hai; Baltas, Michael; Hahn, Hyunggu; Han, Byung Woo; Thao, Do Thi; Vu, Tran Khac

    2016-06-01

    A series of novel hydroxamic acids bearing artemisinin skeleton was designed and synthesized. Some compounds in this series exhibited moderate inhibition against the whole cell HDAC enzymes. Especially, compound 6g displayed potent cytotoxicity against three human cancer cell lines, including HepG2 (liver cancer), MCF-7 (breast cancer) and HL-60 (leukemia cancer), with IC50 values of 2.50, 2.62 and 1.28μg/mL, respectively. Docking studies performed with two potent compounds 6a and 6g using Autodock Vina showed that both compounds bound to HDAC2 with relatively high binding affinities from -7.1 to 7.0kcal/mol compared to SAHA (-7.4kcal/mol). It was found in this research that most of the target compounds seemed to be more cytotoxic toward blood cancer cells (HL-60) than liver (HepG2), and breast (MCF-7) cancer cells.

  11. Removal of fluoride ion from aqueous solution by a cerium-poly(hydroxamic acid) resin complex.

    PubMed

    Haron, M J; Yunus, W M

    2001-05-01

    A cerium-loaded poly(hydroxamic acid) chelating ion exchanger was used for fluoride ion removal from aqueous solution. The resin was effective in decreasing the fluoride concentration from 5 mM down to 0.001 mM in acidic pH between 3 and 6. The sorption followed a Langmuir model with a maximum capacity of 0.5 mmol/g. The removal is accomplished by an anion exchange mechanism. The rate constant for the sorption was found to be 9.6 x 10(-2) min-1. A column test shows that the fluoride ion was retained on the column until breakthrough point and the fluoride sorbed in the column can be eluted with 0.1 M NaOH. The column can be reused after being condition with hydrochloric acid at pH 4. The resin was tested and found to be effective for removal of fluoride from actual industrial wastewater.

  12. The Hydroxamate Siderophore Rhequichelin Is Required for Virulence of the Pathogenic Actinomycete Rhodococcus equi

    PubMed Central

    Coulson, Garry B.; Miranda-CasoLuengo, Aleksandra; Vázquez-Boland, José A.; Hondalus, Mary K.

    2012-01-01

    We previously showed that the facultative intracellular pathogen Rhodococcus equi produces a nondiffusible and catecholate-containing siderophore (rhequibactin) involved in iron acquisition during saprophytic growth. Here, we provide evidence that the rhbABCDE cluster directs the biosynthesis of a hydroxamate siderophore, rhequichelin, that plays a key role in virulence. The rhbC gene encodes a nonribosomal peptide synthetase that is predicted to produce a tetrapeptide consisting of N5-formyl-N5-hydroxyornithine, serine, N5-hydroxyornithine, and N5-acyl-N5-hydroxyornithine. The other rhb genes encode putative tailoring enzymes mediating modification of ornithine residues incorporated into the hydroxamate product of RhbC. Transcription of rhbC was upregulated during growth in iron-depleted medium, suggesting that it plays a role in iron acquisition. This was confirmed by deletion of rhbCD, rendering the resulting strain R. equi SID2 unable to grow in the presence of the iron chelator 2,2-dipyridyl. Supernatant of the wild-type strain rescued the phenotype of R. equi SID2. The importance of rhequichelin in virulence was highlighted by the rapid increase in transcription levels of rhbC following infection and the inability of R. equi SID2 to grow within macrophages. Unlike the wild-type strain, R. equi SID2 was unable to replicate in vivo and was rapidly cleared from the lungs of infected mice. Rhequichelin is thus a key virulence-associated factor, although nonpathogenic Rhodococcus species also appear to produce rhequichelin or a structurally closely related compound. Rhequichelin biosynthesis may therefore be considered an example of cooption of a core actinobacterial trait in the evolution of R. equi virulence. PMID:22966042

  13. The hydroxamate siderophore rhequichelin is required for virulence of the pathogenic actinomycete Rhodococcus equi.

    PubMed

    Miranda-Casoluengo, Raúl; Coulson, Garry B; Miranda-Casoluengo, Aleksandra; Vázquez-Boland, José A; Hondalus, Mary K; Meijer, Wim G

    2012-12-01

    We previously showed that the facultative intracellular pathogen Rhodococcus equi produces a nondiffusible and catecholate-containing siderophore (rhequibactin) involved in iron acquisition during saprophytic growth. Here, we provide evidence that the rhbABCDE cluster directs the biosynthesis of a hydroxamate siderophore, rhequichelin, that plays a key role in virulence. The rhbC gene encodes a nonribosomal peptide synthetase that is predicted to produce a tetrapeptide consisting of N(5)-formyl-N(5)-hydroxyornithine, serine, N(5)-hydroxyornithine, and N(5)-acyl-N(5)-hydroxyornithine. The other rhb genes encode putative tailoring enzymes mediating modification of ornithine residues incorporated into the hydroxamate product of RhbC. Transcription of rhbC was upregulated during growth in iron-depleted medium, suggesting that it plays a role in iron acquisition. This was confirmed by deletion of rhbCD, rendering the resulting strain R. equi SID2 unable to grow in the presence of the iron chelator 2,2-dipyridyl. Supernatant of the wild-type strain rescued the phenotype of R. equi SID2. The importance of rhequichelin in virulence was highlighted by the rapid increase in transcription levels of rhbC following infection and the inability of R. equi SID2 to grow within macrophages. Unlike the wild-type strain, R. equi SID2 was unable to replicate in vivo and was rapidly cleared from the lungs of infected mice. Rhequichelin is thus a key virulence-associated factor, although nonpathogenic Rhodococcus species also appear to produce rhequichelin or a structurally closely related compound. Rhequichelin biosynthesis may therefore be considered an example of cooption of a core actinobacterial trait in the evolution of R. equi virulence.

  14. Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goethite

    SciTech Connect

    Kraemer, Stephan M.; Cheah, Sing-Foong; Zapf, Rita; Xu, Jide; Raymond, Kenneth N.; Sposito, Garrison

    1998-08-01

    Hydroxamate siderophores are biologically-synthesized, Fe(III)-specific ligands which are common in soil environments. In this paper, we report an investigation of their adsorption by the iron oxyhydroxide, goethite; their influence on goethite dissolution kinetics; and their ability to affect Pb(II) adsorption by the goethite surface. The siderophores used were desferrioxamine B (DFO-B), a fungal siderophore, and desferrioxamine D1, an acetyl derivative of DFO-B (DFO-D1). Siderophore adsorption isotherms yielded maximum surface concentrations of 1.5 (DFO-B) or 3.5 (DFO-D1) mu-mol/g at pH 6.6, whereas adsorption envelopes showed either cation-like (DFO-B) or ligand-like (DFO-D1) behavior. Above pH 8, the adsorbed concentrations of both siderophores were similar. The dissolution rate of goethite in the presence of 240 mu M DFO-B or DFO-D1 was 0.02 or 0.17 mu-mol/g hr, respectively. Comparison of these results with related literature data on the reactions between goethite and acetohydroxamic acid, a monohydroxamate ligand, suggested that the three hydroxamate groups in DFO-D1 coordinate to Fe(III) surface sites relatively independently. The results also demonstrated a significant depleting effect of 240 mu-M DFO-B or DFO-D1 on Pb(II) adsorption by goethite at pH > 6.5, but there was no effect of adsorbed Pb(II) on the goethite dissolution rate.

  15. Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goethite

    SciTech Connect

    Kraemer, S.M.; Cheah, S.F.; Zapf, R.; Xu, J.; Raymond, K.N.; Sposito, G.

    1999-10-01

    Hydroxamate siderophores are biologically-synthesized, Fe(III)-specific ligands which are common in soil environments. The authors report an investigation of their adsorption by the iron oxyhydroxide, goethite; their influence on goethite dissolution kinetics; and their ability to affect Pb(II) adsorption by the goethite surface. The siderophores used were desferrioxamine B (DFO-B), a fungal siderophore, and desferrioxamine D{sub 1}, an acetyl derivative of DFO-B (DFO-D1). Siderophore adsorption isotherms yielded maximum surface concentrations of 1.5 (DFO-B) or 3.5 (DFO-D1) {micro}mol/g at pH 6.6, whereas adsorption envelopes showed either cation-like (DFO-B) or ligand-like (DFO-D1) behavior. Above pH 8, the adsorbed concentrations of both siderophores were similar. The dissolution rate of goethite in the presence of 240 {micro}M DFO-B or DFO-D1 was 0.02 or 0.17 {micro}mol/g hr, respectively. Comparison of these results with related literature data on the reactions between goethite and acetohydroxamic acid, a monohydroxamate ligand, suggested that the three hydroxamate groups in DFO-D1 coordinate to Fe(III) surface sites relatively independently. The results also demonstrated a significant depleting effect of 240 {micro}M DFO-B or DFO-D1 on Pb(II) adsorption by goethite at pH {gt} 6.5, but there was no effect of adsorbed Pb(II) on the goethite dissolution rate.

  16. Quinolone-based HDAC inhibitors.

    PubMed

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

    2014-08-01

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

  17. Hydroxamate-based colorimetric assay to assess amide bond formation by adenylation domain of nonribosomal peptide synthetases.

    PubMed

    Hara, Ryotaro; Suzuki, Ryohei; Kino, Kuniki

    2015-05-15

    We demonstrated the usefulness of a hydroxamate-based colorimetric assay for predicting amide bond formation (through an aminoacyl-AMP intermediate) by the adenylation domain of nonribosomal peptide synthetases. By using a typical adenylation domain of tyrocidine synthetase (involved in tyrocidine biosynthesis), we confirmed the correlation between the absorbance at 490 nm of the l-Trp-hydroxamate-Fe(3+) complex and the formation of l-Trp-l-Pro, where l-Pro was used instead of hydroxylamine. Furthermore, this assay was adapted to the adenylation domains of surfactin synthetase (involved in surfactin biosynthesis) and bacitracin synthetase (involved in bacitracin biosynthesis). Consequently, the formation of various aminoacyl l-Pro formations was observed.

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

    PubMed

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

    2013-06-13

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

  19. UV-Visible Spectroscopy Detection of Iron(III) Ion on Modified Gold Nanoparticles With a Hydroxamic Acid

    NASA Astrophysics Data System (ADS)

    Karami, C.; Alizadeh, A.; Taher, M. A.; Hamidi, Z.; Bahrami, B.

    2016-09-01

    The present work describes the preparation of gold nanoparticles (AuNPs) functionalized with hydroxamic acid and the use of them in UV-visible spectroscopy detection of iron(III) ions. The prepared AuNPs were thoroughly characterized by using UV-visible spectroscopy, TEM, and 1H NMR techniques. The newly synthesized hydroxamic acid-AuNPs are brown in color due to the intense surface plasmon absorption band centered at 527 nm. In the presence of Fe(III), the surface plasmon absorption band is centered at 540 nm. However, the sensitivity of hydroxamic acid-AuNPs towards other metal ions such as Mg(II), Ca(II), Ag(I), Cu(II), Mn(II), Cr(II), Ni(II), Co(II),Fe(II), Hg(II), and Pb(II) can be negligible. This highly selective sensor allows a direct quantitative assay of Fe(III) with a UVvisible spectroscopy detection limited to 45.8 nM.

  20. A Hydroxamic Acid Anchoring Group for Durable Dye-Sensitized Solar Cells Incorporating a Cobalt Redox Shuttle.

    PubMed

    Higashino, Tomohiro; Kurumisawa, Yuma; Cai, Ning; Fujimori, Yamato; Tsuji, Yukihiro; Nimura, Shimpei; Packwood, Daniel M; Park, Jaehong; Imahori, Hiroshi

    2017-09-11

    A hydroxamic acid group has been employed for the first time as an anchoring group for cobalt-based dye-sensitized solar cells (DSSCs). The porphyrin dye YD2-o-C8HA including a hydroxamic acid anchoring group exhibited a power conversion efficiency (η) of 6.4 %, which is close to that of YD2-o-C8, a representative porphyrin dye incorporating a conventional carboxylic acid. More importantly, YD2-o-C8HA was found to be superior to YD2-o-C8 in terms of both binding ability to TiO2 and durability of cobalt-based DSSCs. Notably, YD2-o-C8HA photocells revealed a higher η-value (4.1 %) than YD2-o-C8 (2.8 %) after 500 h illumination. These results suggest that the hydroxamic acid can be used for DSSCs with other transition-metal-based redox shuttle to ensure high cell durability as well as excellent photovoltaic performance. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Novel Class IIa-Selective Histone Deacetylase Inhibitors Discovered Using an in Silico Virtual Screening Approach.

    PubMed

    Hsu, Kai-Cheng; Liu, Chang-Yi; Lin, Tony Eight; Hsieh, Jui-Hua; Sung, Tzu-Ying; Tseng, Hui-Ju; Yang, Jinn-Moon; Huang, Wei-Jan

    2017-06-12

    Histone deacetylases (HDAC) contain eighteen isoforms that can be divided into four classes. Of these isoform enzymes, class IIa (containing HDAC4, 5, 7 and 9) target unique substrates, some of which are client proteins associated with epigenetic control. Class IIa HDACs are reportedly associated with some neuronal disorders, making HDACs therapeutic targets for treating neurodegenerative diseases. Additionally, some reported HDAC inhibitors contain hydroxamate moiety that chelates with zinc ion to become the cofactor of HDAC enzymes. However, the hydroxamate functional group is shown to cause undesirable effects and has poor pharmacokinetic profile. This study used in silico virtual screening methodology to identify several nonhydroxamate compounds, obtained from National Cancer Institute database, which potentially inhibited HDAC4. Comparisons of the enzyme inhibitory activity against a panel of HDAC isoforms revealed these compounds had strong inhibitory activity against class IIa HDACs, but weak inhibitory activity against class I HDACs. Further analysis revealed that a single residue affects the cavity size between class I and class IIa HDACs, thus contributing to the selectivity of HDAC inhibitors discovered in this study. The discovery of these inhibitors presents the possibility of developing new therapeutic treatments that can circumvent the problems seen in traditional hydroxamate-based drugs.

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

    PubMed

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

    2008-08-14

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

  3. Chemical and structural characterization of hydroxamate siderophore produced by marine Vibrio harveyi.

    PubMed

    Murugappan, R M; Aravinth, A; Karthikeyan, M

    2011-02-01

    In the present study, 22 different bacteria were isolated from open ocean water from the Gulf of Mannar, India. Of the 22 isolates, 4 were identified as Vibrio spp. (VM1, VM2, VM3 and VM4) and found to produce siderophores (iron-binding chelators) under iron-limited conditions. Different media were found to have an influence on siderophore production. Maximum siderophore production was observed with VM1 isolate in MM9 salts medium at 48 h of incubation. The isolate was confirmed as Vibrio harveyi based on 16S rRNA gene sequencing and phylogenetic analysis. Fourier-transform infrared (FTIR) and (1)H nuclear magnetic resonance (NMR) spectra revealed the hydroxamate nature of the siderophore produced. Further characterization of the siderophore revealed it to be of dihydroxamate nature, forming hexadentate ligands with Fe(III) ions. A narrow shift in ultraviolet (UV)-Vis spectrum was observed on photolysis due to ligand oxidation. Growth-promotion bioassay with Aeromonas hydrophila, Staphylococcus aureus and E. coli confirmed the iron-scavenging property of the siderophore produced by Vibrio harveyi.

  4. Linear fusigen as the major hydroxamate siderophore of the ectomycorrhizal Basidiomycota Laccaria laccata and Laccaria bicolor.

    PubMed

    Haselwandter, Kurt; Häninger, Gerlinde; Ganzera, Markus; Haas, Hubertus; Nicholson, Graeme; Winkelmann, Günther

    2013-12-01

    A screening for siderophores produced by the ectomycorrhizal fungi Laccaria laccata and Laccaria bicolor in synthetic low iron medium revealed the release of several different hydroxamate siderophores of which four major siderophores could be identified by high resolution mass spectrometry. While ferricrocin, coprogen and triacetylfusarinine C were assigned as well as other known fungal siderophores, a major peak of the siderophore mixture revealed an average molecular mass of 797 for the iron-loaded compound. High resolution mass spectrometry indicated an absolute mass of m/z = 798.30973 ([M + H](+)). With a relative error of Δ = 0.56 ppm this corresponds to linear fusigen (C33H52N6O13Fe; MW = 797.3). The production of large amounts of linear fusigen by these basidiomycetous mycorrhizal fungi may possibly explain the observed suppression of plant pathogenic Fusarium species. For comparative purposes Fusarium roseum was included in this study as a well known producer of cyclic and linear fusigen.

  5. Hydroxamate siderophore synthesis by Phialocephala fortinii, a typical dark septate fungal root endophyte.

    PubMed

    Bartholdy; Berreck, M; Haselwandter, K

    2001-03-01

    The siderophore production of various isolates of Phialocephala fortinii was assessed quantitatively as well as qualitatively in batch assays under pure culture conditions at different pH values and iron(III) concentrations. We found a distinct effect of both of these parameters on siderophore synthesis and as well as on fungal growth. In comparative analyses of two of the isolates, maximum siderophore production was found at a pH in the range of pH 4.0 to 4.5 while, under the experimental conditions employed, the optimal concentration of ferric iron was determined to be between 20-40 microg iron (III) l(-1) (0.36-0.72 microM, respectively). HPLC analysis of the culture filtrate of most of the isolates of P. fortinii revealed the excretion of ferricrocin as main hydroxamate siderophore, followed by ferrirubin and ferrichrome C. The pattern of release of these three substances proved to be dependent on pH and iron(III) concentration of the culture medium, and to be specific for each isolate under investigation.

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

    PubMed

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

    2001-01-02

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

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

    PubMed Central

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

    2001-01-01

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

  8. The BESCT Lung Cancer Program (Biology, Education, Screening, Chemoprevention, and Treatment)

    DTIC Science & Technology

    2009-03-01

    assay on the A549 cell line, through MACS, we screened 72 combinations of arbitrary size formed from a 19-drug pool across four generations. Fenretinide ...methylation inhibitor 2 0.88 0.84 0.78 10 17 Deguelin Akt inhibitor 12 0.79 0.64 0.39 2 5 Fenretinide Retinoid: proapoptotic 5 0.86 0.66 0.19 6 1...possible subcombinations of FSB— fenretinide , suberoylanilide hydroxamic acid, and bortezomib—(F, S, B, FS, FB, SB, FSB, no treatment control) and ASB in

  9. [Design, synthesis, and biological activities of histone deacetylase inhibitors with diketo ester as zinc binding group].

    PubMed

    Lu, Hui; Su, Hong; Yang, Bo; You, Qi-Dong

    2011-03-01

    Histone deacetylases (HDACs) inhibition causes hyperacetylation of histones leading to growth arrest, differentiation and apoptosis of tumor cells, representing a new strategy in cancer therapy. Many of previously reported HDACs inhibitors are hydroxamic acid derivatives, which could chelate the zinc ion in the active site in a bidentate fashion. However, hydroxamic acids occasionally have produced problems such as poor pharmacokinetics, severe toxicity and low selectivity. Herein we describe the identification of a new series of non-hydroxamate HDACs inhibitors bearing diketo ester moieties as zinc binding group. HDACs inhibition assay and antiproliferation assays in vitro against multiple cancer cell lines were used for evaluation. These compounds displayed low antiproliferative activity against solid tumor cells, while good antiproliferative activity against human leukemic monocyte lymphoma cell line U937. Compound CPUYS707 is the best with GI50 value of 0.31 micromol x L(-1) against U937 cells, which is more potent than SAHA and MS-275. HDACs inhibition activity of these compounds is lower than that expected, further evaluation is needed.

  10. LAT1 activity of carboxylic acid bioisosteres: Evaluation of hydroxamic acids as substrates.

    PubMed

    Zur, Arik A; Chien, Huan-Chieh; Augustyn, Evan; Flint, Andrew; Heeren, Nathan; Finke, Karissa; Hernandez, Christopher; Hansen, Logan; Miller, Sydney; Lin, Lawrence; Giacomini, Kathleen M; Colas, Claire; Schlessinger, Avner; Thomas, Allen A

    2016-10-15

    Large neutral amino acid transporter 1 (LAT1) is a solute carrier protein located primarily in the blood-brain barrier (BBB) that offers the potential to deliver drugs to the brain. It is also up-regulated in cancer cells, as part of a tumor's increased metabolic demands. Previously, amino acid prodrugs have been shown to be transported by LAT1. Carboxylic acid bioisosteres may afford prodrugs with an altered physicochemical and pharmacokinetic profile than those derived from natural amino acids, allowing for higher brain or tumor levels of drug and/or lower toxicity. The effect of replacing phenylalanine's carboxylic acid with a tetrazole, acylsulfonamide and hydroxamic acid (HA) bioisostere was examined. Compounds were tested for their ability to be LAT1 substrates using both cis-inhibition and trans-stimulation cell assays. As HA-Phe demonstrated weak substrate activity, its structure-activity relationship (SAR) was further explored by synthesis and testing of HA derivatives of other LAT1 amino acid substrates (i.e., Tyr, Leu, Ile, and Met). The potential for a false positive in the trans-stimulation assay caused by parent amino acid was evaluated by conducting compound stability experiments for both HA-Leu and the corresponding methyl ester derivative. We concluded that HA's are transported by LAT1. In addition, our results lend support to a recent account that amino acid esters are LAT1 substrates, and that hydrogen bonding may be as important as charge for interaction with the transporter binding site. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. FhuD1, a Ferric Hydroxamate-binding Lipoprotein in Staphylococcus aureus - A case of gene duplication and lateral transfer

    SciTech Connect

    Sebulsky, M. Tom; Speziali, Craig D.; Shilton, Brian H.; Edgell, David R.

    2010-11-16

    Staphylococcus aureus can utilize ferric hydroxamates as a source of iron under iron-restricted growth conditions. Proteins involved in this transport process are: FhuCBG, which encodes a traffic ATPase; FhuD2, a post-translationally modified lipoprotein that acts as a high affinity receptor at the cytoplasmic membrane for the efficient capture of ferric hydroxamates; and FhuD1, a protein with similarity to FhuD2. Gene duplication likely gave rise to fhuD1 and fhuD2. While the genomic locations of fhuCBG and fhuD2 in S. aureus strains are conserved, both the presence and the location of fhuD1 are variable. The apparent redundancy of FhuD1 led us to examine the role of this protein. We demonstrate that FhuD1 is expressed only under conditions of iron limitation through the regulatory activity of Fur. FhuD1 fractions with the cell membrane and binds hydroxamate siderophores but with lower affinity than FhuD2. Using small angle x-ray scattering, the solution structure of FhuD1 resembles that of FhuD2, and only a small conformational change is associated with ferrichrome binding. FhuD1, therefore, appears to be a receptor for ferric hydroxamates, like FhuD2. Our data to date suggest, however, that FhuD1 is redundant to FhuD2 and plays a minor role in hydroxamate transport. However, given the very real possibility that we have not yet identified the proper conditions where FhuD1 does provide an advantage over FhuD2, we anticipate that FhuD1 serves an enhanced role in the transport of untested hydroxamate siderophores and that it may play a prominent role during the growth of S. aureus in its natural environments.

  12. 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.

  13. Bioactive conformation of stromelysin inhibitors determined by transferred nuclear Overhauser effects.

    PubMed Central

    Gonnella, N C; Bohacek, R; Zhang, X; Kolossváry, I; Paris, C G; Melton, R; Winter, C; Hu, S I; Ganu, V

    1995-01-01

    The transferred nuclear Overhauser effect has been used to determine the biologically active conformations of two stromelysin inhibitors. Both inhibitors used in this study were hydroxamic acids generated via chemical synthesis. These structures, representing the conformation of each inhibitor bound to stromelysin, superimposed with excellent agreement. The study also provided information on the shape and orientation of the S2' and S1' pockets of the enzyme relative to thermolysin. Comparisons were made between stromelysin and thermolysin inhibitors to critically examine thermolysin as a template for stromelysin-inhibitor design. The enzyme-bound conformations of these stromelysin inhibitors were determined for use as a template in conformationally restricted drug design. Images Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:7831311

  14. Structure of malonic acid-based inhibitors bound to human neutrophil collagenase. A new binding mode explains apparently anomalous data.

    PubMed Central

    Brandstetter, H.; Engh, R. A.; Von Roedern, E. G.; Moroder, L.; Huber, R.; Bode, W.; Grams, F.

    1998-01-01

    Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases, which have been implicated in various disease processes. Various classes of MMP inhibitors, including hydroxamic acids, phosphinic acids, and thiols, have been previously described. Most of these mimic peptides, and most likely bind analogous to the corresponding peptide substrates. Among the hydroxamic acids, malonic acid derivatives have been used as MMP inhibitors, although optimization of their inhibition potency was not successful. Here we report the design of malonic acid-based inhibitors using the X-ray structure of a collagenase/inhibitor complex, which revealed a nonsubstrate-like binding mode. The proposed beta-type turn-like conformation for the improved inhibitors was confirmed by X-ray crystallography. The observation of nonsubstrate-like binding confirms the original strategy for structure-based modeling of improved malonic acid inhibitors, and explains kinetic data that are inconsistent with substrate-like binding. Detailed interactions for the improved inhibitors seen in the crystal structure also suggest possibilities for further modifications in cycles of structure based drug design. Indeed, we have designed nonpeptidic inhibitors with approximately 500-fold improved inhibition based on these structures. PMID:9655333

  15. Ultra-fast photo-patterning of hydroxamic acid layers adsorbed on TiAlN: The challenge of modeling thermally induced desorption

    NASA Astrophysics Data System (ADS)

    Hemgesberg, Maximilian; Schütz, Simon; Müller, Christine; Schlörholz, Matthias; Latzel, Harald; Sun, Yu; Ziegler, Christiane; Thiel, Werner R.

    2012-10-01

    Long-chain n-alkyl terminated hydroxamic acids (HA) are used for the modification of titanium aluminum nitride (TiAlN) surfaces. HA coatings improve the hydrophobicity of this wear resistant and industrially relevant ceramic. Therefore, HAs with different structural properties are evaluated with respect to their wear resistance and their thermal desorption properties. In order to find new coatings for rewritable offset printing plates, the changes in the surface polarity, composition, and morphology are analyzed by contact angle measurements, X-ray photoemission spectroscopy (XPS), and scanning force microscopy (SFM), respectively. The results are referenced to the strongly bonding molecule n-dodecyl phosphonate (PO11M), which has been used for surface hydrophobization before but proved difficult to remove due to the high laser outputs required for thermal desorption. It is found that for certain HAs, an equally good hydrophobization compared to PO11M can be achieved. Contact angles obtained for different hydroxamic acid coatings can be correlated to their modes of adsorption. Only for selected HA species, resistance to mechanical wear is sufficient for further investigations. Photo-patterning of these hydroxamic acid layers is achieved using a high energy IR laser beam at different energy inputs. Fitting of the obtained data and further evaluation using finite element analysis (FEM) calculations reveal significantly reduced energy consumption of about 20% for the removal of a specific hydroxamic acid coating from the ceramic surface compared to PO11M.

  16. Investigation of Zr(IV) and 89Zr(IV) complexation with hydroxamates: Progress towards designing a better chelator than desferrioxamine B for immuno-PET imaging

    PubMed Central

    Guérard, François; Lee, Yong-Sok; Tripier, Raphaël; Szajek, Lawrence P.; Deschamps, Jeffrey R.; Brechbiel, Martin W.

    2012-01-01

    Single crystal X-ray diffraction show that Zr(IV) forms an octa-coordinated complex with 4 bidentate hydroxamates whose solution structures were investigated utilizing density functional theory at the level of B3LYP/DGDZVP. Stability constants obtained by potentiometry were in accordance with the tendency observed when radiolabeling with 89Zr. PMID:23250287

  17. Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III) Extraction

    PubMed Central

    Haron, Md Jelas; Jahangirian, Hossein; Silong, Sidik; Yusof, Nor Azah; Kassim, Anuar; Rafiee-Moghaddam, Roshanak; Mahdavi, Behnam; Peyda, Mazyar; Abdollahi, Yadollah; Amin, Jamileh

    2012-01-01

    Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO3 and H2SO4. The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III). PMID:22408444

  18. Synthesis and metabolism of inhibitors of ribonucleotide reductase

    SciTech Connect

    Smith, F.T.

    1985-01-01

    In an effort to prepare more effective inhibitors of ribo-nucleotide reductase a series of 2-substituted-4,6-dihydroxypyrimidines was prepared via the appropriately substituted benzamidine. None of the compounds exhibited in vivo activity against L1210 leukemia. No further testing was performed. In order to investigate the metabolism of 3,4-dihydroxybenzohydroxamic acid, a known inhibitor of ribonucleotide reductase, radiolabeled 3,4-dihydroxybenzohydroxamic acid was synthesized by a modification of the procedure of Pichat and Tostain. /sup 14/C-3,4-Dihydroxybenzoic acid was converted to the methyl ester and subsequently reacted with hydroxylamine to give the hydroxamic acid. /sup 14/C-3,4-Dihydroxybenzohydroxamic acid was given i.p. to Sprague-Dawley rats. Excretion occurred mainly (72%) via the urine. HPLC coupled with GC/MS analyses showed that the compound was excreted mainly unchanged. The compound was metabolized to 3,4-dihydroxybenzamide, 4-methoxy-3-hydroxybenzohydroxamic acid, and 4-hydroxy-3-methoxybenzohydroxamic acid. HPLC analysis also showed the lack of formation of any glucuronide or sulfate conjugates through either the hydroxamic acid or catechol functionalities.

  19. Epigenetic modifier-induced biosynthesis of novel acetylenic sterols from Cladosporium colocasiae.

    PubMed

    Liu, Dong-Ze; Liang, Bo-Wen; Li, Xiao-Fei; Yu, Zhi-Yuan

    2014-09-01

    The addition of an HDAC inhibitor, suberoylanilide hydroxamic acid (SBHA), to the culture medium of Cladosporium colocasiae, dramatically altered its metabolic profiles. Analysis of the culture broth extract led to the isolation of two new acetylenic sterols (1-2). The isolated compounds were further evaluated for their cytotoxic and antibacterial activities. Compound 1 showed activity against Bacillus subtilis, affording a zone of inhibition of 12mm at 100μg/disk. However, none of them showed noticeable growth inhibitory effects. Copyright © 2014. Published by Elsevier Inc.

  20. Insecticidal activities of histone deacetylase inhibitors against a dipteran parasite of sheep, Lucilia cuprina.

    PubMed

    Bagnall, Neil H; Hines, Barney M; Lucke, Andrew J; Gupta, Praveer K; Reid, Robert C; Fairlie, David P; Kotze, Andrew C

    2017-04-01

    Histone deacetylase inhibitors (HDACi) are being investigated for the control of various human parasites. Here we investigate their potential as insecticides for the control of a major ecto-parasite of sheep, the Australian sheep blowfly, Lucilia cuprina. We assessed the ability of HDACi from various chemical classes to inhibit the development of blowfly larvae in vitro, and to inhibit HDAC activity in nuclear protein extracts prepared from blowfly eggs. The HDACi prodrug romidepsin, a cyclic depsipeptide that forms a thiolate, was the most potent inhibitor of larval growth, with equivalent or greater potency than three commercial blowfly insecticides. Other HDACi with potent activity were hydroxamic acids (trichostatin, CUDC-907, AR-42), a thioester (KD5170), a disulphide (Psammaplin A), and a cyclic tetrapeptide bearing a ketone (apicidin). On the other hand, no insecticidal activity was observed for certain other hydroxamic acids, fatty acids, and the sesquiterpene lactone parthenolide. The structural diversity of the 31 hydroxamic acids examined here revealed some structural requirements for insecticidal activity; for example, among compounds with flexible linear zinc-binding extensions, greater potency was observed in the presence of branched capping groups that likely make multiple interactions with the blowfly HDAC enzymes. The insecticidal activity correlated with inhibition of HDAC activity in blowfly nuclear protein extracts, indicating that the toxicity was most likely due to inhibition of HDAC enzymes in the blowfly larvae. The inhibitor potencies against blowfly larvae are different from inhibition of human HDACs, suggesting some selectivity for human over blowfly HDACs, and a potential for developing compounds with the inverse selectivity. In summary, these novel findings support blowfly HDAC enzymes as new targets for blowfly control, and point to development of HDAC inhibitors as a promising new class of insecticides.

  1. Inhibitors incorporating zinc-binding groups target the GlcNAc-PI de-N-acetylase in Trypanosoma brucei, the causative agent of African sleeping sickness.

    PubMed

    Abdelwahab, Nuha Z; Crossman, Arthur T; Sullivan, Lauren; Ferguson, Michael A J; Urbaniak, Michael D

    2012-03-01

    Disruption of glycosylphosphatidylinositol biosynthesis is genetically and chemically validated as a drug target against the protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. The N-acetylglucosamine-phosphatidylinositol de-N-acetylase (deNAc) is a zinc metalloenzyme responsible for the second step of glycosylphosphatidylinositol biosynthesis. We recently reported the synthesis of eight deoxy-2-C-branched monosaccharides containing carboxylic acid, hydroxamic acid, or N-hydroxyurea substituents at the C2 position that may act as zinc-binding groups. Here, we describe the synthesis of a glucocyclitol-phospholipid incorporating a hydroxamic acid moiety and report the biochemical evaluation of the monosaccharides and the glucocyclitol-phospholipid as inhibitors of the trypanosome deNAc in the cell-free system and against recombinant enzyme. Monosaccharides with carboxylic acid or hydroxamic acid substituents were found to be the inhibitors of the trypanosome deNAc with IC(50) values 0.1-1.5mM and the glucocyclitol-phospholipid was found to be a dual inhibitor of the deNAc and the α1-4-mannose transferase with an apparent IC(50)= 19±0.5μm. © 2011 John Wiley & Sons A/S.

  2. Talarolide A, a Cyclic Heptapeptide Hydroxamate from an Australian Marine Tunicate-Associated Fungus, Talaromyces sp. (CMB-TU011).

    PubMed

    Dewapriya, Pradeep; Prasad, Pritesh; Damodar, Rakesh; Salim, Angela A; Capon, Robert J

    2017-04-06

    A miniaturized 24-well plate microbioreactor approach was used to explore secondary metabolite media dependence in an Australian marine tunicate-associated fungus, Talaromyces sp. (CMB TU011). Detailed chemical investigations of an antifungal M1-saline cultivation yielded talarolide A (1), only the second reported natural cyclic peptide hydroxamate, and the first from a fungus. The antifungal properties of the M1-saline extract were attributed to the known diterpene glycoside sordarin (2). Structure elucidation of 1 and 2 was achieved by detailed spectroscopic analysis, with amino acid configurations in 1 assigned by the C3 and C18 Marfey's methods, and l-Ala and d-Ala regiochemistry by the recently reported 2D C3 Marfey's method.

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

    PubMed Central

    Li, Youxuan; Woster, Patrick M.

    2015-01-01

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

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

    PubMed

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

    2016-10-15

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

  5. Recent developments in the design of specific Matrix Metalloproteinase inhibitors aided by structural and computational studies.

    PubMed

    Rao, B Govinda

    2005-01-01

    It has been 10 years since a 3-dimensional structure of the catalytic domain of a Matrix Metalloprotease (MMP) was revealed for the first time in 1994. More than 80 structures of different MMPs in apo and inhibited forms, determined by X-ray crystallography and NMR methods, have been published by the end of year 2003. A large number of very potent inhibitors have been disclosed in published and patent literature. Several MMP inhibitors entered clinical trials for the treatment of cancer and arthritis. Most of the first generation inhibitors have hydroxamic acid as the Zinc-binding group and have limited specificity. With the failure of these inhibitors in clinical trials, more efforts have been directed to the design of specific inhibitors with different Zn-binding groups in recent years. This review will summarize all the published structural information and focus on the inhibitors that were designed to take advantage of the nonprime side of the MMP active site using structural information and computational analysis. Representative structures from all MMPs are aligned to a target structure to provide a better understanding of the similarities and differences of the active site pockets. This analysis supports the view that the differences in the nonprime side pockets provide better opportunities for designing inhibitors with higher specificity. Published information on all the Zinc-binding groups of MMP inhibitors is reviewed for the first time. Pros and cons of inhibitors with non-hydroxamate Zinc-binding groups in terms of specificity, toxicity and pharmacokinetic properties are discussed.

  6. Hydroxamic acid interactions with solvated cerium hydroxides in the flotation of monazite and bastnäsite-Experiments and DFT study

    NASA Astrophysics Data System (ADS)

    Sarvaramini, A.; Azizi, D.; Larachi, F.

    2016-11-01

    Density functional theory (DFT) simulations and experiments were performed to clarify the interaction mechanisms between hydroxamic acid collectors and cerium hydroxides during the flotation of bastnäsite and monazite minerals. These minerals showed considerable floatability at moderately alkaline pH which was related to the adsorption of hydroxamic acids on their surfaces as confirmed by vibrational spectroscopic and zeta potential measurements. DFT simulations showed that at moderately alkaline pH, the interactions between solvated Ce(OH)2+ and Ce(OH)2+ and heptyl-hydroxamic acid (HHA) anions resulted in the formation of, respectively, [Ce(OH)(HHA)x(H2O)y]2-x (x[y = ] = 1[6],2[3],3[1]) and [Ce(OH)2(HHA)x(H2O)y]1-x (x[y = ] = 1[5],2[1],3[0]) complexes. The collector anions were found to interact directly through formation of two covalent bonds between their two polar-head oxygen atoms and cerium in the hydroxide complexes. However, formation of such new bonds resulted in breakage of a few covalent/electrostatic bonds between cerium and water molecules initially present in the first hydration shell of the rare-earth metal cation. Building up in the electric double layer of the semi-soluble minerals, these complexes, and by extension, those from other rare-earth elements belonging to monazite and bastnäsite, are speculated to play a role in the interactions between rare-earth minerals and hydroxamic acid collectors.

  7. Γ-aminobutyric acid(C) (GABAC) selective antagonists derived from the bioisosteric modification of 4-aminocyclopent-1-enecarboxylic acid: amides and hydroxamates.

    PubMed

    Locock, Katherine E S; Yamamoto, Izumi; Tran, Priscilla; Hanrahan, Jane R; Chebib, Mary; Johnston, Graham A R; Allan, Robin D

    2013-07-11

    Series of compounds were generated via the bioisosteric replacement of the carboxylate of 4-ACPCA (2) with hydroxamate or amide groups. All compounds from this study exhibited increased selectivity for GABAC, the most potent being 4-ACPHA (10a, IC50 = 13 μM) and 4-ACPAM (11a, IC50 = 10 μM). This provides evidence that a zwitterionic structure is not essential for GABAC antagonists, rather the emphasis lies in appropriate heteroatoms to participate in hydrogen bonding.

  8. ABCD1 deletion-induced mitochondrial dysfunction is corrected by SAHA: implication for adrenoleukodystrophy.

    PubMed

    Baarine, Mauhamad; Beeson, Craig; Singh, Avtar; Singh, Inderjit

    2015-05-01

    X-linked Adrenoleukodystrophy (X-ALD), an inherited peroxisomal metabolic neurodegenerative disorder, is caused by mutations/deletions in the ATP-binding cassette transporter (ABCD1) gene encoding peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). Metabolic dysfunction in X-ALD is characterized by the accumulation of very long chain fatty acids ≥ C22:0) in the tissues and plasma of patients. Here, we investigated the mitochondrial status following deletion of ABCD1 in B12 oligodendrocytes and U87 astrocytes. This study provides evidence that silencing of peroxisomal protein ABCD1 produces structural and functional perturbations in mitochondria. Activities of electron transport chain-related enzymes and of citric acid cycle (TCA cycle) were reduced; mitochondrial redox status was dysregulated and the mitochondrial membrane potential was disrupted following ABCD1 silencing. A greater reduction in ATP levels and citrate synthase activities was observed in oligodendrocytes as compared to astrocytes. Furthermore, most of the mitochondrial perturbations induced by ABCD1 silencing were corrected by treating cells with suberoylanilide hydroxamic acid, an Histone deacetylase inhibitor. These observations indicate a novel relationship between peroxisomes and mitochondria in cellular homeostasis and the importance of intact peroxisomes in relation to mitochondrial integrity and function in the cell types that participate in the pathobiology of X-ALD. These observations suggest suberoylanilide hydroxamic acid as a potential therapy for X-ALD. Schematic description of the effects of loss of peroxisomal ATP-binding cassette transporter D1 (ABCD1) gene on cellular Redox and mitochondrial activities and their correction by suberoylanilide hydroxamic acid (SAHA) treatment. Pathogenomic accumulation of very long chain fatty acids (VLCFA) as a result of loss of ABCD1 leads to dysfunctions of mitochondrial biogenesis and its activities. Treatment with SAHA corrects

  9. 1,3,4-Oxadiazole-containing histone deacetylase inhibitors: anticancer activities in cancer cells.

    PubMed

    Valente, Sergio; Trisciuoglio, Daniela; De Luca, Teresa; Nebbioso, Angela; Labella, Donatella; Lenoci, Alessia; Bigogno, Chiara; Dondio, Giulio; Miceli, Marco; Brosch, Gerald; Del Bufalo, Donatella; Altucci, Lucia; Mai, Antonello

    2014-07-24

    We describe 1,3,4-oxadiazole-containing hydroxamates (2) and 2-aminoanilides (3) as histone deacetylase inhibitors. Among them, 2t, 2x, and 3i were the most potent and selective against HDAC1. In U937 leukemia cells, 2t was more potent than SAHA in inducing apoptosis, and 3i displayed cell differentiation with a potency similar to MS-275. In several acute myeloid leukemia (AML) cell lines, as well as in U937 cells in combination with doxorubicin, 3i showed higher antiproliferative effects than SAHA.

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

    PubMed Central

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

    2015-01-01

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

  11. Exploration of the labeling of [11C]Tubastatin A at the hydroxamic acid site with [11C]carbon monoxide

    PubMed Central

    Lu, Shuiyu; Zhang, Yi; Kalin, Jay; Cai, Lisheng; Kozikowski, Alan P.; Pike, Victor W.

    2015-01-01

    We aimed to label tubastatin A (1) with carbon-11 (t1/2 = 20.4 min) in the hydroxamic acid site to provide a potential radiotracer for imaging histone deacetylase 6 (HDAC6) in vivo with positron emission tomography (PET). Initial attempts at a one-pot Pd-mediated insertion of [11C]carbon monoxide between the aryl iodide (2) and hydroxylamine gave low radiochemical yields (< 5%) of [11C]1. Labeling was achieved in useful radiochemical yields (16.1 ± 5.6%, n = 4) through a two-step process based on Pd-mediated insertion of [11C]carbon monoxide between the aryl iodide (2) and p-nitrophenol to give the [11C]p-nitrophenyl ester ([11C]5), followed by ultrasound-assisted hydroxyaminolysis of the activated ester with excess hydroxylamine in DMSO/THF mixture in the presence of a strong phosphazene base P1-t-Bu. However, the success in labeling the hydroxamic acid group of [11C]tubastatin A was not transferable to the labeling of three other model hydroxamic acids. PMID:26647018

  12. Iron chelating active packaging: Influence of competing ions and pH value on effectiveness of soluble and immobilized hydroxamate chelators.

    PubMed

    Ogiwara, Yoshiko; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2016-04-01

    Many packaged foods utilize synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit iron-promoted oxidation or microbial growth which would result in quality loss. To address consumer demands for all natural products, we have previously developed a non-migratory iron chelating active packaging material by covalent immobilization of polyhydroxamate and demonstrated its efficacy in delaying lipid oxidation. Herein, we demonstrate the ability of this hydroxamate-functionalized iron chelating active packaging to retain iron chelating capacity; even in the presence of competing ions common in food. Both immobilized and soluble hydroxamate chelators retained iron chelating capacity in the presence of calcium, magnesium, and sodium competing ions, although at pH 5.0 the presence of calcium reduced immobilized hydroxamate iron chelation. A strong correlation was found between colorimetric and mass spectral analysis of iron chelation by the chelating packaging material. Such chelating active packaging may support reducing additive use in product formulations, while retaining quality and shelf life.

  13. Enhancing the Pharmacokinetic Properties of Botulinum Neurotoxin Serotype A Protease Inhibitors Through Rational Design.

    PubMed

    Capek, Petr; Zhang, Yan; Barlow, Deborah J; Houseknecht, Karen L; Smith, Garry R; Dickerson, Tobin J

    2011-06-15

    Botulinum neurotoxin (BoNT), the etiological agent that causes the neuroparalytic disease botulism, has become a highly studied drug target in light of the potential abuse of this toxin as a weapon of bioterrorism. In particular, small molecule inhibitors of the light chain metalloprotease of BoNT serotype A have received significant attention and a number of small molecule and biologic inhibitors have been reported. However, all small molecules reported have been identified from either primary screens or medicinal chemistry follow-up studies, and the pharmacokinetic profiles of these compounds have not been addressed. In this study, we have removed the pharmacologic liabilities of one of the best compounds reported to date, 2,4-dichlorocinnamate hydroxamic acid, and in the process, uncovered a related class of benzothiophene hydroxamic acids that are significantly more potent inhibitors of the BoNT/A light chain, while also possessing greatly improved ADME properties, with the best compound showing the most potent inhibition of BoNT/A light chain reported (K(i) = 77 nM). Using a strategy of incorporating traditional drug development filters early into the discovery process, potential liabilities in BoNT/A lead compounds have been illuminated and removed, clearing the path for advancement into further pharmacologic optimization and in vivo efficacy testing.

  14. Stimulation of cleavage of membrane proteins by calmodulin inhibitors.

    PubMed Central

    Díaz-Rodríguez, E; Esparís-Ogando, A; Montero, J C; Yuste, L; Pandiella, A

    2000-01-01

    The ectodomain of several membrane-bound proteins can be shed by proteolytic cleavage. The activity of the proteases involved in shedding is highly regulated by several intracellular second messenger pathways, such as protein kinase C (PKC) and intracellular Ca(2+). Recently, the shedding of the adhesion molecule L-selectin has been shown to be regulated by the interaction of calmodulin (CaM) with the cytosolic tail of L-selectin. Prevention of CaM-L-selectin interaction by CaM inhibitors or mutation of a CaM binding site in L-selectin induced L-selectin ectodomain shedding. Whether this action of CaM inhibitors also affects other membrane-bound proteins is not known. In the present paper we show that CaM inhibitors also stimulate the cleavage of several other transmembrane proteins, such as the membrane-bound growth factor precursors pro-transforming growth factor-alpha and pro-neuregulin-alpha2c, the receptor tyrosine kinase, TrkA, and the beta-amyloid precursor protein. Cleavage induced by CaM inhibitors was a rapid event, and resulted from the activation of a mechanism that was independent of PKC or intracellular Ca(2+) increases, but was highly sensitive to hydroxamic acid-based metalloprotease inhibitors. Mutational analysis of the intracellular domain of the TrkA receptor indicated that CaM inhibitors may stimulate membrane-protein ectodomain cleavage by mechanisms independent of CaM-substrate interaction. PMID:10677354

  15. Charting the mechanism and reactivity of zirconium oxalate with hydroxamate ligands using density functional theory: implications in new chelate design.

    PubMed

    Holland, Jason P; Vasdev, Neil

    2014-07-14

    The reaction of [(89)Zr(C2O4)4](4-) with the tris-hydroxamate ligand desferrioxamine B (DFO) provides the basis of radiolabelling biological vectors such as antibodies and proteins with the radionuclide (89)Zr for positron emission tomography imaging. In this work, density functional theory methods were used to investigate the mechanism of reaction from [Zr(C2O4)4](4-) to Zr(MeAHA)4 by ligand substitution with N-methyl acetohydroxamate (MeAHA). Calculations were performed under simulated basic and acidic conditions. Ligand substitution under basic conditions was found to be thermodynamically feasible with an overall calculated change in solvation free energy, ΔGsol = -97 kJ mol(-1) using the B3LYP/DGDZVP methodology and a water continuum solvation model. In contrast, an acid-mediated mechanism of ligand substitution was found to be thermodynamically non-feasible. Molecular orbital analysis provides a rationale for the difference in thermodynamic stability between [Zr(C2O4)4](4-) and Zr(MeAHA)4. Overall, the DFT calculations are consistent with observed experimental (89)Zr-radiolabelling reactions and suggest that computational methods may prove useful in designing novel chelates for increasing the thermodynamic and kinetic stability of (89)Zr-complexes in vivo.

  16. Identification and occurrence of the hydroxamate siderophores aerobactin, putrebactin, avaroferrin and ochrobactin C as virulence factors from entomopathogenic bacteria.

    PubMed

    Hirschmann, Merle; Grundmann, Florian; Bode, Helge B

    2017-06-27

    Effective iron acquisition and fine-tuned intracellular iron storage systems are the main prerequisites for a successful host invasion by a pathogen. Bacteria have developed several different strategies to sequester this essential element from their environment, one relies on the secretion of low molecular weight compounds with high affinity for ferric iron, the so-called siderophores. Here, we report hydroxamate siderophore structures produced by entomopathogenic bacteria of the species Xenorhabdus and Photorhabdus, which are known for their potential to produce bioactive natural products, required for their role as nematode symbiont and insect pathogen. Four siderophores could be identified, namely aerobactin, putrebactin, avaroferrin and ochrobactin C, which was found previously only in marine bacteria. While the putrebactin and avaroferrin producing biosynthesis gene cluster (BGC) is more widespread and most likely was present in a common ancestor of these bacteria, the aerobactin and ochrobactin producing BGC was probably taken up by a few strains individually. For aerobactin a role in virulence towards Galleria mellonella larvae is shown. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Matrix metalloproteinase inhibitors.

    PubMed

    Wojtowicz-Praga, S M; Dickson, R B; Hawkins, M J

    1997-01-01

    The matrix metalloproteinases (MMPs) are a family of at least fifteen secreted and membrane-bound zinc-endopeptidases. Collectively, these enzymes can degrade all of the components of the extracellular matrix, including fibrallar and non-fibrallar collagens, fibronectin, laminin and basement membrane glycoproteins. MMPs are thought to be essential for the diverse invasive processes of angiogenesis and tumor metastasis. Numerous studies have shown that there is a close association between expression of various members of the MMP family by tumors and their proliferative and invasive behavior and metastatic potential. In some of human cancers a positive correlation has also been demonstrated between the intensity of new blood vessel growth (angiogenesis) and the likelihood of developing metastases. Thus, control of MMP activity in these two different contexts has generated considerable interest as a possible therapeutic target. The tissue inhibitors of metalloproteinases (TIMPs) are naturally occurring proteins that specifically inhibit matrix metalloproteinases, thus maintaining balance between matrix destruction and formation. An imbalance between MMPs and the associated TIMPs may play a significant role in the invasive phenotype of malignant tumors. TIMP-1 has been shown to inhibit tumor-induced angiogenesis in experimental systems. These findings raised the possibility of using an agent that affects expression or activity of MMPs as an anti-cancer therapy. TIMPs are probably not suitable for pharmacologic applications due to their short half-life in vivo. Batimastat (BB-94) and marimastat (BB-2516) are synthetic, low-molecular weight MMP inhibitors. They have a collagen-mimicking hydroxamate structure, which facilitates chelation of the zinc ion in the active site of the MMPs. These compounds inhibit MMPs potently and specifically. Batimastat was the first synthetic MMP inhibitor studied in humans with advanced malignancies, but its usefulness has been limited by

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

    PubMed

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

    2010-08-11

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

  19. Identification of the KDM2/7 Histone Lysine Demethylase Subfamily Inhibitor and its Antiproliferative Activity

    PubMed Central

    2013-01-01

    Histone Nε-methyl lysine demethylases KDM2/7 have been identified as potential targets for cancer therapies. On the basis of the crystal structure of KDM7B, we designed and prepared a series of hydroxamate analogues bearing an alkyl chain. Enzyme assays revealed that compound 9 potently inhibits KDM2A, KDM7A, and KDM7B, with IC50s of 6.8, 0.2, and 1.2 μM, respectively. While inhibitors of KDM4s did not show any effect on cancer cells tested, the KDM2/7-subfamily inhibitor 9 exerted antiproliferative activity, indicating the potential for KDM2/7 inhibitors as anticancer agents. PMID:23964788

  20. Rational Design Synthesis and Evaluation of New Selective Inhibitors of Microbial Class II (Zinc Dependent) Fructose Bis-phosphate Aldolases

    SciTech Connect

    R Daher; M Coincon; M Fonvielle; P Gest; M Guerin; M Jackson; J Sygusch; M Therisod

    2011-12-31

    We report the synthesis and biochemical evaluation of several selective inhibitors of class II (zinc dependent) fructose bis-phosphate aldolases (Fba). The products were designed as transition-state analogues of the catalyzed reaction, structurally related to the substrate fructose bis-phosphate (or sedoheptulose bis-phosphate) and based on an N-substituted hydroxamic acid, as a chelator of the zinc ion present in active site. The compounds synthesized were tested on class II Fbas from various pathogenic microorganisms and, by comparison, on a mammalian class I Fba. The best inhibitor shows Ki against class II Fbas from various pathogens in the nM range, with very high selectivity (up to 105). Structural analyses of inhibitors in complex with aldolases rationalize and corroborate the enzymatic kinetics results. These inhibitors represent lead compounds for the preparation of new synthetic antibiotics, notably for tuberculosis prophylaxis.

  1. Phosphorus-based SAHA analogues as histone deacetylase inhibitors.

    PubMed

    Kapustin, Galina V; Fejér, György; Gronlund, Jennifer L; McCafferty, Dewey G; Seto, Edward; Etzkorn, Felicia A

    2003-08-21

    [structure: see text] Three analogues of suberoyl anilide hydroxamic acid (SAHA) with phosphorus metal-chelating functionalities were synthesized as inhibitors of histone deacetylases (HDACs). The compounds showed weak activity for HeLa nuclear extracts (IC(50) = 0.57-6.1 mM), HDAC8 (IC(50) = 0.28-0.41 mM), and histone-deacetylase-like protein (HDLP, IC(50) = 0.33-1.9 mM), suggesting that the transition state of HDAC is not analogous to zinc proteases. Antiproliferative activity against A2780 cancer cells (IC(50) = 0.11-0.12 mM), comparable to SAHA (0.15 mM), was observed.

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

    PubMed

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

    2016-04-13

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

  3. Extended X-ray absorption fine structure data analysis of copper (II) hydroxamic acid mixed ligand complexes

    NASA Astrophysics Data System (ADS)

    Parsai, N.; Mishra, A.; Shrivastava, B. D.

    2014-09-01

    The X-ray absorption spectra of copper mixed ligand complexes, having hydroxamic acid as one of the ligands, have been recorded at the K-edge of copper at BL-8 Dispersive EXAFS beamline at the 2.5 GeV INDUS-2 Synchrotron, RRCAT, Indore, India. For the analysis of EXAFS data, crystallographic data of the complex or of its analog is required, which is not available. Hence, for the analysis of EXAFS data, theoretical EXAFS data of the studied complexes have been generated using the EXAFS equation employing computer software program Mathcad. Firstly, the experimental data has been processed using the computer program Athena to obtain the normalized absorption versus energy data. From the experimental EXAFS data, the phase shift parameter (an energy independent constant 5) has been computed using Lytle, Sayers and Stern's (LSS) method. The backscattering amplitude has been taken from the available theoretical tabulations and other parameters have been taken from crystallographic data of the copper metal. Fourier transforms of both the experimental and theoretical data have been computed, and the two Fourier transforms are found to agree with each other for all the complexes. The position of the first peak in the Fourier transform gives the value of the first shell bond length, which is shorter than the actual bond length as a result of energy dependence of the phase factor (5(k)) in the sine function of the EXAFS equation. Since, the Fourier transform method and LSS method both are uncorrected for phase and other parameters of the EXAFS equation, the present method gives phase uncorrected bond length of the first coordination shell.

  4. Extended X-ray absorption fine structure data analysis of copper (II) hydroxamic acid mixed ligand complexes

    NASA Astrophysics Data System (ADS)

    Parsai, N.; Mishra, A.; Shrivastava, B. D.

    2014-09-01

    The X-ray absorption spectra of copper mixed ligand complexes, having hydroxamic acid as one of the ligands, have been recorded at the K-edge of copper at BL-8 Dispersive EXAFS beamline at the 2.5 GeV INDUS-2 Synchrotron, RRCAT, Indore, India. For the analysis of EXAFS data, crystallographic data of the complex or of its analog is required, which is not available. Hence, for the analysis of EXAFS data, theoretical EXAFS data of the studied complexes have been generated using the EXAFS equation employing computer software program Mathcad. Firstly, the experimental data has been processed using the computer program Athena to obtain the normalized absorption versus energy data. From the experimental EXAFS data, the phase shift parameter (an energy independent constant 5) has been computed using Lytle, Sayers and Stern's (LSS) method. The backscattering amplitude has been taken from the available theoretical tabulations and other parameters have been taken from crystallographic data of the copper metal. Fourier transforms of both the experimental and theoretical data have been computed, and the two Fourier transforms are found to agree with each other for all the complexes. The position of the first peak in the Fourier transform gives the value of the first shell bond length, which is shorter than the actual bond length as a result of energy dependence of the phase factor (δ(k)) in the sine function of the EXAFS equation. Since, the Fourier transform method and LSS method both are uncorrected for phase and other parameters of the EXAFS equation, the present method gives phase uncorrected bond length of the first coordination shell.

  5. ACE inhibitors

    MedlinePlus

    ... ACE inhibitors There are many different names and brands of ACE inhibitors. Most work as well as ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  6. Unexpected formation of a copper(II) 12-metallacrown-4 with (S)-glutamic-gamma-hydroxamic acid: a thermodynamic and spectroscopic study in aqueous solution.

    PubMed

    Tegoni, Matteo; Dallavalle, Francesco; Belosi, Barbara; Remelli, Maurizio

    2004-05-07

    The equilibria of copper(II) with (S)-glutamic-gamma-hydroxamic acid (H2L) were investigated in aqueous solution by different techniques: glass electrode potentiometry; calorimetry; VIS and CD spectrophotometry; and ES-MS. An unexpected pentacopper(II) 12-metallacrown-4 [Cu5L4H(-4)](2-) was detected, analogous to those well known formed by alpha- and beta-aminohydroxamic acids, but of lower stability. Another five species were found: [CuLH]+; [CuL2H2]; [Cu2L2]; [CuL2H]-; and [CuL2]2-. Their structures are proposed based on both spectroscopic and calorimetric data.

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

    PubMed

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

    2009-05-01

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

  8. SF2312 is a natural phosphonate inhibitor of Enolase

    PubMed Central

    Maxwell, David; Lin, Yu-Hsi; Hammoudi, Naima; Peng, Zhenghong; Pisaneschi, Federica; Link, Todd M.; Lee, Gilbert R.; Sun, Duoli; Prasad, Basvoju A. Bhanu; Di Francesco, Maria Emilia; Czako, Barbara; Asara, John M.; Wang, Y. Alan; Bornmann, William; DePinho, Ronald A.; Muller, Florian L.

    2016-01-01

    Despite being critical for energy generation in most forms of life, few if any microbial antibiotics specifically inhibit glycolysis. To develop a specific inhibitor of the glycolytic enzyme Enolase 2 for the treatment of cancers with deletion of Enolase 1, we modeled the synthetic tool compound inhibitor, Phosphonoacetohydroxamate (PhAH) into the active site of human ENO2. A ring-stabilized analogue of PhAH, with the hydroxamic nitrogen linked to the alpha-carbon by an ethylene bridge, was predicted to increase binding affinity by stabilizing the inhibitor in a bound conformation. Unexpectedly, a structure based search revealed that our hypothesized back-bone-stabilized PhAH bears strong similarity to SF2312, a phosphonate antibiotic of unknown mode of action produced by the actinomycete Micromonospora, which is active under anaerobic conditions. Here, we present multiple lines of evidence, including a novel X-ray structure, that SF2312 is a highly potent, low nM inhibitor of Enolase. PMID:27723749

  9. Tetrahydrofuranyl and Tetrahydropyranyl Protection of Amino Acid Side-Chains Enables Synthesis of a Hydroxamate-Containing Aminoacylated tRNA†

    PubMed Central

    Lambert, Lester J.; Miller, Marvin J.; Huber, Paul W.

    2015-01-01

    The ability to specifically engineer metal binding sites into target proteins has far-reaching consequences ranging from the development of new biocatalysts and imaging reagents to the production of proteins with increased stability. We report the efficient tRNA-mediated incorporation of the hydroxamate containing amino acid, Nε-acetyl-Nε-hydroxy-l-lysine, into a transcription factor (TFIIIA). Because this amino acid is compact, hydrophilic, and uncharged at physiological pH, it should have little or no effect on protein folding or solubility. The Nε-hydroxy group of the hydroxamate is refractory to photodeprotection and required the identification of reagents for O-protection that are compatible with the synthesis of acylated tRNA. Tetrahydrofuranyl and tetrahydropyranyl O-protecting groups can be removed using mild acid conditions and allowed for an orthogonal protection strategy in which deprotection of the amino acid side chain precedes ligation of an acylated dinucleotide to a truncated suppressor tRNA. These protecting groups will provide a valuable alternative for O-protection, especially in cases where photodeprotection cannot be used. PMID:25562392

  10. FptA, the Fe(III)-pyochelin receptor of Pseudomonas aeruginosa: a phenolate siderophore receptor homologous to hydroxamate siderophore receptors.

    PubMed Central

    Ankenbauer, R G; Quan, H N

    1994-01-01

    The Pseudomonas aeruginosa siderophore pyochelin is structurally unique among siderophores and possesses neither hydroxamate- nor catecholate-chelating groups. The structural gene encoding the 75-kDa outer membrane Fe(III)-pyochelin receptor FptA has been isolated by plasmid rescue techniques and sequenced. The N-terminal amino acid sequence of the isolated FptA protein corresponded to that deduced from the nucleotide sequence of the fptA structural gene. The mature FptA protein has 682 amino acids and a molecular mass of 75,993 Da and has considerable overall homology with the hydroxamate siderophore receptors FpvA of P. aeruginosa, PupA and PupB of Pseudomonas putida, and FhuE of Escherichia coli. This observation indicates that homologies between siderophore receptors are an unreliable predictor of siderophore ligand class recognition by a given receptor. The fptA gene was strongly regulated by iron; fptA transcription was totally repressed by 30 microM FeCl3, as determined by Northern (RNA) blotting. The promoter of the fptA gene contained the sequence 5'-ATAATGATAAGCATTATC-3', which matches the consensus E. coli Fur-binding site at 17 of 18 positions. The -10 promoter region and transcriptional start site of the fptA gene reside within this Fur-binding site. Images PMID:8288523

  11. Inhibition of potato lipoxygenase by linoleyl hydroxamic acid: kinetic and EPR spectral evidence for a two-step reaction.

    PubMed Central

    Butovich, Igor A; Reddy, C Channa

    2002-01-01

    The reaction mechanism of an electrophoretically pure potato tuber lipoxygenase (ptLOX) was studied by EPR spectroscopy. An EPR spectrum of the 'native' ptLOX recorded at 4.5+/-0.5 K showed signals of a high-spin (pseudo) axial Fe(3+) with a g-value of approx. 6.3+/-0.1 with a shoulder at g=5.9+/-0.1, and a rhombic Fe(3+) signal at g=4.35+/-0.05. When the enzyme was treated with a 2-fold molar excess of 13(S)-hydroperoxyoctadecadienoic acid [13(S)-HPODE], a 3-fold increase in the integral intensity of the g=6.3 signal was observed, indicating that 25% of the native ptLOX iron was in ferrous state. The positional isomer 9(S)-HPODE caused similar spectral changes. Therefore the catalytic centre of ptLOX appears to accommodate both positional isomers of linoleic acid hydroperoxides in a manner that ensures proper alignment of their hydroperoxy groups with the iron centre of the enzyme. Treatment of the Fe(3+)-ptLOX form with a 3-fold molar excess of linoleyl hydroxamic acid (LHA) completely quenched the g=6.3 signal. Concurrently, a dramatic increase in the signal at g=4.35 was detected, which was attributed to a newly formed LHA-Fe(3+)-ptLOX complex. The spectral characteristics of the complex are similar to those of a 4-nitrocatechol-Fe(3+)-ptLOX complex. From these observations, we conclude that LHA did not reduce Fe(3+) to Fe(2+), but rather formed a LHA-Fe(3+)-ptLOX complex. Formation of such a complex may be responsible for the inhibitory activity of LHA, at least in the initial stages of enzyme inhibition. A prolonged 15 min incubation of the complex at 23+/-1 degrees C led to the partial quenching of the g=4.35 signal. The quenching is attributed to the reduction of Fe(3+)-ptLOX by LHA, with concomitant formation of its oxidation product(s). A kinetic scheme for the inhibition is proposed. PMID:11985498

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

    PubMed

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

    2014-11-01

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

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

    PubMed

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

    2016-02-15

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

  14. Induced production of mycotoxins in an endophytic fungus from the medicinal plant Datura stramonium L.

    PubMed

    Sun, Jieyin; Awakawa, Takayoshi; Noguchi, Hiroshi; Abe, Ikuro

    2012-10-15

    Epigenetic modifiers, including DNA methyltransferase (DNMT) or histone deacetylase (HDAC) inhibitors, are useful to induce the expression of otherwise dormant biosynthetic genes under standard laboratory conditions. We isolated several endophytic fungi from the medicinal plant Datura stramonium L., which produces pharmaceutically important tropane alkaloids, including scopolamine and hyoscyamine. Although none of the endophytic fungi produced the tropane alkaloids, supplementation of a DNMT inhibitor, 5-azacytidine, and/or a HDAC inhibitor, suberoylanilide hydroxamic acid, to the culture medium induced the production of mycotoxins, including alternariol, alternariol-5-O-methyl ether, 3'-hydroxyalternariol-5-O-methyl ether, altenusin, tenuazonic acid, and altertoxin II, by the endophytic fungus Alternaria sp. This is the first report of a mycotoxin-producing endophytic fungus from the medicinal plant D. stramonium L. This work demonstrates that treatments with epigenetic modifiers induce the production of mycotoxins, thus providing a useful tool to explore the biosynthetic potential of the microorganisms.

  15. Antibiotic Activity and Characterization of BB-3497, a Novel Peptide Deformylase Inhibitor

    PubMed Central

    Clements, John M.; Beckett, R. Paul; Brown, Anthony; Catlin, Graham; Lobell, Mario; Palan, Shilpa; Thomas, Wayne; Whittaker, Mark; Wood, Stephen; Salama, Sameeh; Baker, Patrick J.; Rodgers, H. Fiona; Barynin, Vladimir; Rice, David W.; Hunter, Michael G.

    2001-01-01

    Peptide deformylase (PDF) is an essential bacterial metalloenzyme which deformylates the N-formylmethionine of newly synthesized polypeptides and as such represents a novel target for antibacterial chemotherapy. To identify novel PDF inhibitors, we screened a metalloenzyme inhibitor library and identified an N-formyl-hydroxylamine derivative, BB-3497, and a related natural hydroxamic acid antibiotic, actinonin, as potent and selective inhibitors of PDF. To elucidate the interactions that contribute to the binding affinity of these inhibitors, we determined the crystal structures of BB-3497 and actinonin bound to Escherichia coli PDF at resolutions of 2.1 and 1.75 Å, respectively. In both complexes, the active-site metal atom was pentacoordinated by the side chains of Cys 90, His 132, and His 136 and the two oxygen atoms of N-formyl-hydroxylamine or hydroxamate. BB-3497 had activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis, and activity against some gram-negative bacteria. Time-kill analysis showed that the mode of action of BB-3497 was primarily bacteriostatic. The mechanism of resistance was via mutations within the formyltransferase gene, as previously described for actinonin. While actinonin and its derivatives have not been used clinically because of their poor pharmacokinetic properties, BB-3497 was shown to be orally bioavailable. A single oral dose of BB-3497 given 1 h after intraperitoneal injection of S. aureus Smith or methicillin-resistant S. aureus protected mice from infection with median effective doses of 8 and 14 mg/kg of body weight, respectively. These data validate PDF as a novel target for the design of a new generation of antibacterial agents. PMID:11158755

  16. Antibiotic activity and characterization of BB-3497, a novel peptide deformylase inhibitor.

    PubMed

    Clements, J M; Beckett, R P; Brown, A; Catlin, G; Lobell, M; Palan, S; Thomas, W; Whittaker, M; Wood, S; Salama, S; Baker, P J; Rodgers, H F; Barynin, V; Rice, D W; Hunter, M G

    2001-02-01

    Peptide deformylase (PDF) is an essential bacterial metalloenzyme which deformylates the N-formylmethionine of newly synthesized polypeptides and as such represents a novel target for antibacterial chemotherapy. To identify novel PDF inhibitors, we screened a metalloenzyme inhibitor library and identified an N-formyl-hydroxylamine derivative, BB-3497, and a related natural hydroxamic acid antibiotic, actinonin, as potent and selective inhibitors of PDF. To elucidate the interactions that contribute to the binding affinity of these inhibitors, we determined the crystal structures of BB-3497 and actinonin bound to Escherichia coli PDF at resolutions of 2.1 and 1.75 A, respectively. In both complexes, the active-site metal atom was pentacoordinated by the side chains of Cys 90, His 132, and His 136 and the two oxygen atoms of N-formyl-hydroxylamine or hydroxamate. BB-3497 had activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis, and activity against some gram-negative bacteria. Time-kill analysis showed that the mode of action of BB-3497 was primarily bacteriostatic. The mechanism of resistance was via mutations within the formyltransferase gene, as previously described for actinonin. While actinonin and its derivatives have not been used clinically because of their poor pharmacokinetic properties, BB-3497 was shown to be orally bioavailable. A single oral dose of BB-3497 given 1 h after intraperitoneal injection of S. aureus Smith or methicillin-resistant S. aureus protected mice from infection with median effective doses of 8 and 14 mg/kg of body weight, respectively. These data validate PDF as a novel target for the design of a new generation of antibacterial agents.

  17. Discovery of a novel Nrf2 inhibitor that induces apoptosis of human acute myeloid leukemia cells.

    PubMed

    Zhang, JinFeng; Su, Le; Ye, Qing; Zhang, ShangLi; Kung, HsiangFu; Jiang, Fan; Jiang, GuoSheng; Miao, JunYing; Zhao, BaoXiang

    2017-01-31

    Nuclear factor-erythroid 2-related factor 2 (Nrf2) is persistently activated in many human tumors including acute myeloid leukemia (AML). Therefore, inhibition of Nrf2 activity may be a promising target in leukemia therapy. Here, we used an antioxidant response element-luciferase reporter system to identify a novel pyrazolyl hydroxamic acid derivative, 1-(4-(tert-Butyl)benzyl)-3-(4-chlorophenyl)-N-hydroxy-1H pyrazole-5-carboxamide (4f), that inhibited Nrf2 activity. 4f had a profound growth-inhibitory effect on three AML cell lines, THP-1, HL-60 and U937, and a similar anti-growth effect in a chick embryo model. Moreover, flow cytometry of AML cells revealed increased apoptosis with 4f (10 μM) treatment for 48 h. The protein levels of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase were enhanced in all three AML cell types. Furthermore, Nrf2 protein level was downregulated by 4f. Upregulation of Nrf2 by tert-butylhydroquinone (tBHQ) or Nrf2 overexpression could ameliorate 4f-induced growth inhibition and apoptosis. Treatment with 4f reduced both B-cell lymphoma-2 (Bcl-2) expression and Bcl-2/Bcl-2-associated X protein (Bax) ratio, which indicated that 4f induced apoptosis, at least in part, via mitochondrial-dependent signaling. Therefore, as an Nrf2 inhibitor, the pyrazolyl hydroxamic acid derivative 4f may be a promising agent in AML therapy.

  18. Identification and Characterization of fhuD1 and fhuD2, Two Genes Involved in Iron-Hydroxamate Uptake in Staphylococcus aureus

    PubMed Central

    Sebulsky, M. Tom; Heinrichs, David E.

    2001-01-01

    Staphylococcus aureus can utilize several hydroxamate siderophores for growth under iron-restricted conditions. Previous findings have shown that S. aureus possesses a cytoplasmic membrane-associated traffic ATPase that is involved in the specific transport of iron(III)-hydroxamate complexes. In this study, we have identified two additional genes, termed fhuD1 and fhuD2, whose products are involved in this transport process in S. aureus. We have shown that fhuD2 codes for a posttranslationally modified lipoprotein that is anchored in the cytoplasmic membrane, while the deduced amino acid sequence predicts the same for fhuD1. The predicted FhuD1 and FhuD2 proteins share 41.0% identity and 56.4% total similarity with each other, 45.9 and 49.1% total similarity with the FhuD homolog in Bacillus subtilis, and 29.3 and 24.6% total similarity with the periplasmic FhuD protein from Escherichia coli. Insertional inactivation and gene replacement of both genes showed that while FhuD2 is involved in the transport of iron(III) in complex with ferrichrome, ferrioxamine B, aerobactin, and coprogen, FhuD1 shows a more limited substrate range, capable of only iron(III)-ferrichrome and iron(III)-ferrioxamine B transport in S. aureus. Nucleotide sequences present upstream of both fhuD1 and fhuD2 predict the presence of consensus Fur binding sequences. In agreement, transcription of both genes was negatively regulated by exogenous iron levels through the activity of the S. aureus Fur protein. PMID:11489851

  19. Pyrido[2,3-d]pyrimidin-5-ones: A Novel Class of Antiinflammatory Macrophage Colony-Stimulating Factor-1 Receptor Inhibitors

    SciTech Connect

    Huang, Hui; Hutta, Daniel A.; Rinker, James M.; Hu, Huaping; Parsons, William H.; Schubert, Carsten; DesJarlais, Renee L.; Crysler, Carl S.; Chaikin, Margery A.; Donatelli, Robert R.; Chen, Yanmin; Cheng, Deping; Zhou, Zhao; Yurkow, Edward; Manthey, Carl L.; Player, Mark R.

    2010-10-01

    A series of pyrido[2,3-d]pyrimidin-5-ones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). FMS inhibitors may be useful in treating rheumatoid arthritis and other chronic inflammatory diseases. Structure-based optimization of the lead amide analogue 10 led to hydroxamate analogue 37, which possessed excellent potency and an improved pharmacokinetic profile. During the chronic phase of streptococcal cell wall-induced arthritis in rats, compound 37 (10, 3, and 1 mg/kg) was highly effective at reversing established joint swelling. In an adjuvant-induced arthritis model in rats, 37 prevented joint swelling partially at 10 mg/kg. In this model, osteoclastogenesis and bone erosion were prevented by low doses (1 or 0.33 mg/kg) that had minimal impact on inflammation. These data underscore the potential of FMS inhibitors to prevent erosions and reduce symptoms in rheumatoid arthritis.

  20. Structure of the metal-dependent deacetylase LpxC from Yersinia enterocolitica complexed with the potent inhibitor CHIR-090 .

    PubMed

    Cole, Kathryn E; Gattis, Samuel G; Angell, Heather D; Fierke, Carol A; Christianson, David W

    2011-01-18

    The first committed step of lipid A biosynthesis is catalyzed by UDP-(3-O-((R)-3-hydroxymyristoyl))-N-acetylglucosamine deacetylase, a metal-dependent deacetylase also known as LpxC. Because lipid A is essential for bacterial viability, the inhibition of LpxC is an appealing therapeutic strategy for the treatment of Gram-negative bacterial infections. Here we report the 1.79 Å resolution X-ray crystal structure of LpxC from Yersinia enterocolitica (YeLpxC) complexed with the potent hydroxamate inhibitor CHIR-090. This enzyme is a nearly identical orthologue of LpxC from Yersinia pestis (99.7% sequence identity), the pathogen that causes bubonic plague. Similar to the inhibition of LpxC from Escherichia coli, CHIR-090 inhibits YeLpxC via a two-step slow, tight-binding mechanism with an apparent K(i) of 0.54 ± 0.14 nM followed by conversion of the E·I to E·I* species with a rate constant of 0.11 ± 0.01 min(-1). The structure of the LpxC complex with CHIR-090 shows that the inhibitor hydroxamate group chelates the active site zinc ion, and the "tail" of the inhibitor binds in the hydrophobic tunnel in the active site. This hydrophobic tunnel is framed by a βαβ subdomain that exhibits significant conformational flexibility as it accommodates inhibitor binding. CHIR-090 displays a 27 mm zone of inhibition against Y. enterocolitica in a Kirby-Bauer antibiotic assay, which is comparable to its reported activity against other Gram-negative species including E. coli and Pseudomonas aeruginosa. This study demonstrates that the inhibition of LpxC should be explored as a potential therapeutic and/or prophylatic response to infection by weaponized Yersinia species.

  1. Binding of 5-phospho-D-arabinonohydroxamate and 5-phospho-D-arabinonate inhibitors to zinc phosphomannose isomerase from Candida albicans studied by polarizable molecular mechanics and quantum mechanics.

    PubMed

    Roux, Celine; Gresh, Nohad; Perera, Lalith E; Piquemal, Jean-Philip; Salmon, Laurent

    2007-04-15

    Type I phosphomannose isomerase (PMI) is a Zn-dependent metalloenzyme involved in the isomerization of D-fructose 6-phosphate to D-mannose 6-phosphate. One of our laboratories has recently designed and synthesized 5-phospho-D-arabinonohydroxamate (5PAH), an inhibitor endowed with a nanomolar affinity for PMI (Roux et al., Biochemistry 2004, 43, 2926). By contrast, the 5-phospho-D-arabinonate (5PAA), in which the hydroxamate moiety is replaced by a carboxylate one, is devoid of inhibitory potency. Subsequent biochemical studies showed that in its PMI complex, 5PAH binds Zn(II) through its hydroxamate moiety rather than through its phosphate. These results have stimulated the present theoretical investigation in which we resort to the SIBFA polarizable molecular mechanics procedure to unravel the structural and energetical aspects of 5PAH and 5PAA binding to a 164-residue model of PMI. Consistent with the experimental results, our theoretical studies indicate that the complexation of PMI by 5PAH is much more favorable than by 5PAA, and that in the 5PAH complex, Zn(II) ligation by hydroxamate is much more favorable than by phosphate. Validations by parallel quantum-chemical computations on model of the recognition site extracted from the PMI-inhibitor complexes, and totaling up to 140 atoms, showed the values of the SIBFA intermolecular interaction energies in such models to be able to reproduce the quantum-chemistry ones with relative errors < 3%. On the basis of the PMI-5PAH SIBFA energy-minimized structure, we report the first hypothesis of a detailed view of the active site of the zinc PMI complexed to the high-energy intermediate analogue inhibitor, which allows us to identify active site residues likely involved in the proton transfer between the two adjacent carbons of the substrates.

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

    PubMed

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

    2016-09-01

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

  3. Thermal decomposition of matrix metalloproteinase inhibitors: evidence of solid state dimerization.

    PubMed

    Rabel Riley, Shelley R; Vickery, Rodney D; Nemeth, Gregory A; Haas, Michael J; Kasprzak, Daniel J; Maurin, Michael B

    2011-01-25

    The thermal properties of three matrix metalloproteinase (MMP) inhibitors were investigated using a variety of instrumental methods. Differential scanning calorimetry revealed highly exothermic processes for all compounds above 200°C, and thermogravimetric analysis resulted in significant step-wise weight losses at the temperatures corresponding to the exothermic transitions. Hot stage microscopy observations for several compounds showed evolution of gas bubbles from crystals at temperatures that correlated with the exotherms. Thermal decomposition involving the hydroxamic acid functional group was suspected and further evaluated using various analytical techniques including reversed-phase HPLC, LC-MS-MS, TGA-FTIR and NMR. The mechanism proposed in the thermal decomposition involves a Lossen Rearrangement to form a dimeric species containing a urea linkage. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. A novel histone deacetylase inhibitor augments tamoxifen-mediated attenuation of breast carcinoma growth.

    PubMed

    Restall, Christina; Doherty, Judy; Liu, Hong Bin; Genovese, Rosemary; Paiman, Lisa; Byron, Keith A; Anderson, Robin L; Dear, Anthony E

    2009-07-15

    Earlier we generated novel derivatives of the hydroxamate-based histone deacetylase inhibitor (HDACi), Oxamflatin (Ox), which demonstrate considerable HDACi activity. Here the effects of one such derivative, Metacept-1 (MCT-1), alone or in combination with tamoxifen on mammary tumour growth have been assessed in a syngeneic orthotopic model. MCT-1 alone resulted in a trend towards inhibition of growth of 4T1.2 mammary tumours. Since the combination of MCT-1 and tamoxifen up-regulates estrogen receptor expression in 4T1.2 cells in vitro, we tested this combination and found a significant reduction in primary tumour growth over tamoxifen treatment alone. Taken together, these observations suggest that the novel HDACi MCT-1 may warrant further exploration in the treatment of estrogen receptor positive breast carcinoma, particularly when used in combination with conventional agents such as tamoxifen.

  5. Speciation, liquid-liquid extraction, sequential separation, preconcentration, transport and ICP-AES determination of Cr(III), Mo(VI) and W(VI) with calix-crown hydroxamic acid in high purity grade materials and environmental samples.

    PubMed

    Agrawal, Y K; Sharma, K R

    2005-07-15

    A new functionalized calix[6]crown hydroxamic acid is reported for the speciation, liquid-liquid extraction, sequential separation and trace determination of Cr(III), Mo(VI) and W(VI). Chromium(III), molybdenum(VI) and tungsten(VI) are extracted at pH 4.5, 1.5M HCl and 6.0M HCl, respectively with calixcrown hydroxamic acid (37,38,39,40,41,42-hexahydroxy7,25,31-calix[6]crown hydroxamic acid) in chloroform in presence of large number of cations and anions. The extraction mechanism is investigated. The various extraction parameters, appropriate pH/M HCl, choice of solvent, effect of the reagent concentration, temperature and distribution constant have been studied. The speciation, preconcentration and kinetic of transport has been investigated. The maximum transport is observed 35, 45 and 30min for chromium(III), molybdenum(VI) and tungsten(IV), respectively. For trace determination the extracts were directly inserted into the plasma for inductively coupled plasma atomic emission spectrometry, ICP-AES, measurements of chromium, molybdenum and tungsten which increase the sensitivity by 30-fold, with detection limits of 3ngml(-1). The method is applied for the determination of chromium, molybdenum and tungsten in high purity grade ores, biological and environmental samples. The chromium was recovered from the effluent of electroplating industries.

  6. Carboxylesterase inhibitors

    PubMed Central

    Hatfield, M. Jason; Potter, Philip M.

    2011-01-01

    Introduction Carboxylesterases play major roles in the hydrolysis of numerous therapeutically active compounds. This is, in part, due to the prevalence of the ester moiety in these small molecules. However, the impact these enzymes may play on drug stability and pharmacokinetics is rarely considered prior to molecule development. Therefore, the application of selective inhibitors of this class of proteins may have utility in modulating the metabolism, distribution and toxicity of agents that are subjected to enzyme hydrolysis. Areas covered This review details the development of all such compounds dating back to 1986, but principally focuses on the very recent identification of selective human carboxylesterases inhibitors. Expert opinion The implementation of carboxylesterase inhibitors may significantly revolutionize drug discovery. Such molecules may allow for improved efficacy of compounds inactivated by this class of enzymes and/or reduce the toxicity of agents that are activated by these proteins. Furthermore, since lack of carboxylesterase activity appears to have no obvious biological consequence, these compounds could be applied in combination with virtually any esterified drug. Therefore, inhibitors of these proteins may have utility in altering drug hydrolysis and distribution in vivo. The characteristics, chemical and biological properties, and potential uses of such agents, are discussed here. PMID:21609191

  7. Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

    PubMed

    Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

    2015-11-01

    Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to

  8. Nε-lysine acetylation determines dissociation from GAP junctions and lateralization of connexin 43 in normal and dystrophic heart

    PubMed Central

    Colussi, Claudia; Rosati, Jessica; Straino, Stefania; Spallotta, Francesco; Berni, Roberta; Stilli, Donatella; Rossi, Stefano; Musso, Ezio; Macchi, Emilio; Mai, Antonello; Sbardella, Gianluca; Castellano, Sabrina; Chimenti, Cristina; Frustaci, Andrea; Nebbioso, Angela; Altucci, Lucia; Capogrossi, Maurizio C.; Gaetano, Carlo

    2011-01-01

    Wanting to explore the epigenetic basis of Duchenne cardiomyopathy, we found that global histone acetylase activity was abnormally elevated and the acetylase P300/CBP-associated factor (PCAF) coimmunoprecipitated with connexin 43 (Cx43), which was Nε-lysine acetylated and lateralized in mdx heart. This observation was paralleled by Cx43 dissociation from N-cadherin and zonula occludens 1, whereas pp60-c-Src association was unaltered. In vivo treatment of mdx with the pan-histone acetylase inhibitor anacardic acid significantly reduced Cx43 Nε-lysine acetylation and restored its association to GAP junctions (GJs) at intercalated discs. Noteworthy, in normal as well as mdx mice, the class IIa histone deacetylases 4 and 5 constitutively colocalized with Cx43 either at GJs or in the lateralized compartments. The class I histone deacetylase 3 was also part of the complex. Treatment of normal controls with the histone deacetylase pan-inhibitor suberoylanilide hydroxamic acid (MC1568) or the class IIa-selective inhibitor 3-{4-[3-(3-fluorophenyl)-3-oxo-1-propen-1-yl]-1-methyl-1H-pyrrol-2-yl}-N-hydroxy-2-propenamide (MC1568) determined Cx43 hyperacetylation, dissociation from GJs, and distribution along the long axis of ventricular cardiomyocytes. Consistently, the histone acetylase activator pentadecylidenemalonate 1b (SPV106) hyperacetylated cardiac proteins, including Cx43, which assumed a lateralized position that partly reproduced the dystrophic phenotype. In the presence of suberoylanilide hydroxamic acid, cell to cell permeability was significantly diminished, which is in agreement with a Cx43 close conformation in the consequence of hyperacetylation. Additional experiments, performed with Cx43 acetylation mutants, revealed, for the acetylated form of the molecule, a significant reduction in plasma membrane localization and a tendency to nuclear accumulation. These results suggest that Cx43 Nε-lysine acetylation may have physiopathological consequences for cell to

  9. Histone deacetylase inhibitor pracinostat in doublet therapy: a unique strategy to improve therapeutic efficacy and to tackle herculean cancer chemoresistance.

    PubMed

    Ganai, Shabir Ahmad

    2016-09-01

    Context Histone deacetylase inhibitors (HDACi) have shown promising results in neurodegeneration and cancer. Hydroxamate HDACi, including vorinostat, have shown encouraging results in haematological malignancies, but the poor pharmacokinetic of these inhibitors leads to insufficient tumour concentration limiting their application against solid malignancies. Objective This article deals with novel HDAC inhibitor pracinostat (SB939) and delineates its therapeutic role in solid and haematological malignancies. The article provides rigorous details about the underlying molecular mechanisms modulated by pracinostat to exert cytotoxic effect. The article further highlights the doublet therapy that may be used to tackle monotonous cancer chemoresistance. Methods Both old and the latest literature on pracinostat was retrieved from diverse sources, such as PubMed, Science Direct, Springer Link, general Google search using both pracinostat and SB939 keywords in various ways: after thorough evaluation the topic which can fulfil the current gap was chosen. Results Pracinostat shows potent anticancer activity against both solid and haematological malignancies compared to the FDA-approved drug vorinostat. This marvellous inhibitor has better physicochemical, pharmaceutical and pharmacokinetic properties than the defined inhibitor vorinostat. Pracinostat has  >100-fold more affinity towards HDACs compared to other zinc-dependent metalloenzymes and shows maximum efficacy when used in doublet therapy. Conclusion Pracinostat shows potent anticancer activity even against therapeutically challenging cancers when used in doublet therapy. However, the triplet combination studies of the defined inhibitor that may prove even more beneficial are still undone, emphasizing the desperate need of further research in the defined gap.

  10. Designed Inhibitors of Insulin-Degrading Enzyme Regulate the Catabolism and Activity of Insulin

    SciTech Connect

    Leissring, Malcolm A.; Malito, Enrico; Hedouin, Sabrine; Reinstatler, Lael; Sahara, Tomoko; Abdul-Hay, Samer O.; Choudhry, Shakeel; Maharvi, Ghulam M.; Fauq, Abdul H.; Huzarska, Malwina; May, Philip S.; Choi, Sungwoon; Logan, Todd P.; Turk, Benjamin E.; Cantley, Lewis C.; Manolopoulou, Marika; Tang, Wei-Jen; Stein, Ross L.; Cuny, Gregory D.; Selkoe, Dennis J.

    2010-09-20

    Insulin is a vital peptide hormone that is a central regulator of glucose homeostasis, and impairments in insulin signaling cause diabetes mellitus. In principle, it should be possible to enhance the activity of insulin by inhibiting its catabolism, which is mediated primarily by insulin-degrading enzyme (IDE), a structurally and evolutionarily distinctive zinc-metalloprotease. Despite interest in pharmacological inhibition of IDE as an attractive anti-diabetic approach dating to the 1950s, potent and selective inhibitors of IDE have not yet emerged. We used a rational design approach based on analysis of combinatorial peptide mixtures and focused compound libraries to develop novel peptide hydroxamic acid inhibitors of IDE. The resulting compounds are {approx} 10{sup 6} times more potent than existing inhibitors, non-toxic, and surprisingly selective for IDE vis-a-vis conventional zinc-metalloproteases. Crystallographic analysis of an IDE-inhibitor complex reveals a novel mode of inhibition based on stabilization of IDE's 'closed,' inactive conformation. We show further that pharmacological inhibition of IDE potentiates insulin signaling by a mechanism involving reduced catabolism of internalized insulin. Conclusions/Significance: The inhibitors we describe are the first to potently and selectively inhibit IDE or indeed any member of this atypical zinc-metalloprotease superfamily. The distinctive structure of IDE's active site, and the mode of action of our inhibitors, suggests that it may be possible to develop inhibitors that cross-react minimally with conventional zinc-metalloproteases. Significantly, our results reveal that insulin signaling is normally regulated by IDE activity not only extracellularly but also within cells, supporting the longstanding view that IDE inhibitors could hold therapeutic value for the treatment of diabetes.

  11. Overlapping and Divergent Actions of Structurally Distinct Histone Deacetylase Inhibitors in Cardiac Fibroblasts.

    PubMed

    Schuetze, Katherine B; Stratton, Matthew S; Blakeslee, Weston W; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; Kuo, Yin-Ming; Andrews, Andrew J; Gilbert, Tonya M; Hooker, Jacob M; McKinsey, Timothy A

    2017-04-01

    Inhibitors of zinc-dependent histone deacetylases (HDACs) profoundly affect cellular function by altering gene expression via changes in nucleosomal histone tail acetylation. Historically, investigators have employed pan-HDAC inhibitors, such as the hydroxamate trichostatin A (TSA), which simultaneously targets members of each of the three zinc-dependent HDAC classes (classes I, II, and IV). More recently, class- and isoform-selective HDAC inhibitors have been developed, providing invaluable chemical biology probes for dissecting the roles of distinct HDACs in the control of various physiologic and pathophysiological processes. For example, the benzamide class I HDAC-selective inhibitor, MGCD0103 [N-(2-aminophenyl)-4-[[(4-pyridin-3-ylpyrimidin-2-yl)amino]methyl] benzamide], was shown to block cardiac fibrosis, a process involving excess extracellular matrix deposition, which often results in heart dysfunction. Here, we compare the mechanisms of action of structurally distinct HDAC inhibitors in isolated primary cardiac fibroblasts, which are the major extracellular matrix-producing cells of the heart. TSA, MGCD0103, and the cyclic peptide class I HDAC inhibitor, apicidin, exhibited a common ability to enhance histone acetylation, and all potently blocked cardiac fibroblast cell cycle progression. In contrast, MGCD0103, but not TSA or apicidin, paradoxically increased expression of a subset of fibrosis-associated genes. Using the cellular thermal shift assay, we provide evidence that the divergent effects of HDAC inhibitors on cardiac fibroblast gene expression relate to differential engagement of HDAC1- and HDAC2-containing complexes. These findings illustrate the importance of employing multiple compounds when pharmacologically assessing HDAC function in a cellular context and during HDAC inhibitor drug development.

  12. A quantum chemical study of molecular properties and QSPR modeling of oximes, amidoximes and hydroxamic acids with nucleophilic activity against toxic organophosphorus agents

    NASA Astrophysics Data System (ADS)

    Alencar Filho, Edilson B.; Santos, Aline A.; Oliveira, Boaz G.

    2017-04-01

    The proposal of this work includes the use of quantum chemical methods and cheminformatics strategies in order to understand the structural profile and reactivity of α-nucleophiles compounds such as oximes, amidoximes and hydroxamic acids, related to hydrolysis rate of organophosphates. Theoretical conformational study of 41 compounds were carried out through the PM3 semiempirical Hamiltonian, followed by the geometry optimization at the B3LYP/6-31+G(d,p) level of theory, complemented by Polarized Continuum Model (PCM) to simulate the aqueous environment. In line with the experimental hypothesis about hydrolytic power, the strength of the Intramolecular Hydrogen Bonds (IHBs) at light of the Bader's Quantum Theory of Atoms in Molecules (QTAIM) is related to the preferential conformations of α-nucleophiles. A set of E-Dragon descriptors (1,666) were submitted to a variable selection through Ordered Predictor Selection (OPS) algorithm. Five descriptors, including atomic charges obtained from the Natural Bond Orbitals (NBO) protocol jointly with a fragment index associated to the presence/absence of IHBs, provided a Quantitative Structure-Property Relationship (QSPR) model via Multiple Linear Regression (MLR). This model showed good validation parameters (R2 = 0.80, Qloo2 = 0.67 and Qext2 = 0.81) and allowed the identification of significant physicochemical features on the molecular scaffold in order to design compounds potentially more active against organophosphorus poisoning.

  13. Molecular octopus: octa functionalized calix[4]resorcinarene-hydroxamic acid [C4RAHA] for selective extraction, separation and preconcentration of U(VI).

    PubMed

    Jain, Vinod K; Pillai, Shibu G; Pandya, Rujul A; Agrawal, Yaduvendra K; Shrivastav, Pranav S

    2005-01-30

    A solvent extraction separation of uranium, in the presence of thorium, cerium and lanthanides with a new calix[4]resorcinarene bearing eight hydroxamic acid groups (C4RAHA) is described. Quantitative extraction of uranium is possible in ethyl acetate solution of C4RAHA at pH 8.0. The lambda(max) and molar absorptivity (varepsilon) for uranium is 356nm and 8352Lmol(-1)cm(-1). The Binding ratio of uranium with C4RAHA as evaluated by Job's method is 4:1. The system obeys Beer's law over the range 0.075-6.0mugml(-1) of uranium with Sandell sensitivity 0.0284mugcm(-2). A preconcentration factor of 142 was achieved by directly aspirating the extract for GF-AAS measurements. The two-phase stability constant evaluated at 25 degrees C for uranium is 15.91. The complexation is characterized by favorable enthalpy and entropy changes. A liquid membrane transport study of uranium was carried out from source to the receiving phase under controlled conditions and a mechanism of transport is proposed. Uranium has been determined in standard and environmental samples.

  14. Wheat bulb fly (Delia coarctata, Fallén, Diptera: Anthomyiidae) larval response to hydroxamic acid constituents of host-plant root exudates.

    PubMed

    Rogers, C D; Evans, K A

    2013-06-01

    Wheat bulb fly (WBF, Delia coarctata, Fallén, Diptera: Anthomyiidae) is a pest of commercial importance in wheat, barley and rye, with attacked crops failing to produce full potential yields. Females do not oviposit in association with a host-plant; therefore, prompt location of a suitable host is critical to the survival of the newly hatched larvae. The objective of this study was to conduct choice test bioassays to assess the attraction of WBF larvae to specific chemical constituents of WBF host-plant root exudates, the hydroxamic acids DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and MBOA (6-methoxy-benzoxazolin-2-one). The larval response to four concentrations of each test compound was assessed in arena bioassays. Analysis using a Rayleigh test of uniformity of the final resting positions of larvae in response to these chemicals indicated attraction. These results go some way to explaining the mechanisms by which WBF larvae locate host plants, giving the potential to develop semiochemical based control strategies.

  15. Lysine acetylation targets protein complexes and co-regulates major cellular functions.

    PubMed

    Choudhary, Chunaram; Kumar, Chanchal; Gnad, Florian; Nielsen, Michael L; Rehman, Michael; Walther, Tobias C; Olsen, Jesper V; Mann, Matthias

    2009-08-14

    Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600 lysine acetylation sites on 1750 proteins and quantified acetylation changes in response to the deacetylase inhibitors suberoylanilide hydroxamic acid and MS-275. Lysine acetylation preferentially targets large macromolecular complexes involved in diverse cellular processes, such as chromatin remodeling, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other major posttranslational modifications.

  16. Non-coding nucleotides and amino acids near the active site regulate peptide deformylase expression and inhibitor susceptibility in Chlamydia trachomatis

    PubMed Central

    Bao, Xiaofeng; Pachikara, Niseema D.; Oey, Christopher B.; Balakrishnan, Amit; Westblade, Lars F.; Tan, Ming; Chase, Theodore; Nickels, Bryce E.

    2011-01-01

    Chlamydia trachomatis, an obligate intracellular bacterium, is a highly prevalent human pathogen. Hydroxamic-acid-based matrix metalloprotease inhibitors can effectively inhibit the pathogen both in vitro and in vivo, and have exhibited therapeutic potential. Here, we provide genome sequencing data indicating that peptide deformylase (PDF) is the sole target of the inhibitors in this organism. We further report molecular mechanisms that control chlamydial PDF (cPDF) expression and inhibition efficiency. In particular, we identify the σ66-dependent promoter that controls cPDF gene expression and demonstrate that point mutations in this promoter lead to resistance by increasing cPDF transcription. Furthermore, we show that substitution of two amino acids near the active site of the enzyme alters enzyme kinetics and protein stability. PMID:21719536

  17. Anti-tumor effects of the Notch pathway in gastrointestinal stromal tumors.

    PubMed

    Dumont, Amaury G; Yang, Yanwen; Reynoso, David; Katz, Daniela; Trent, Jonathan C; Hughes, Dennis P

    2012-09-01

    Gastrointestinal stromal tumors (GISTs) are driven by gain-of-function mutations of KIT or PDGFRa. The introduction of imatinib has significantly extended survival for patients. However, most patients develop resistances. Notch signaling is a conserved developmental pathway known to play a critical role in the development of several cancers, functioning as a tumor promoter or a tumor suppressor. Given that the normal progenitor cell for GIST, the interstitial cell of Cajal, has characteristics similar to those of cells of neuroendocrine origin, we hypothesized that Notch pathway impacts the biology of GIST cells. In this study, we retrovirally and pharmacologically manipulated the Notch pathway in human GIST cells. We also performed a retrospective analysis of a cohort on 15 primary tumors to determine the role of Hes1, a major target gene of Notch, as a prognostic marker for GIST. Constitutively, active intracellular domain of Notch1 (ICN1) expression potently induced growth arrest and downregulated KIT expression in vitro. Additionally, treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid caused dose-dependent upregulation of Notch1 expression and a parallel decrease in viability in these cells. Retroviral silencing of downstream targets of Notch (dominant-negative Hes1) and pharmacological inhibition of Notch activation (γ-secretase inhibition) partially rescued GIST cells from suberoylanilide hydroxamic acid treatment. GIST patients with high Hes1 mRNA levels have a significantly longer relapse-free survival. These results identify a novel anti-tumor effect of Notch1 and cross talk between the Notch and KIT pathways. Thus, activation of this pathway by treatment with histone deacetylase inhibitors is an appealing potential therapeutic strategy for GISTs. Précis: This study is the first report of the tumor suppressor effects of Notch pathway in gastrointestinal stromal tumors via a negative feedback with the oncogene KIT and may

  18. 3D-QSAR, Molecular Docking and Molecular Dynamics Simulation of Pseudomonas aeruginosa LpxC Inhibitors.

    PubMed

    Zuo, Ke; Liang, Li; Du, Wenyi; Sun, Xin; Liu, Wei; Gou, Xiaojun; Wan, Hua; Hu, Jianping

    2017-05-06

    As an important target for the development of novel antibiotics, UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) has been widely studied. Pyridone methylsulfone hydroxamate (PMH) compounds can effectively inhibit the catalytic activity of LpxC. In this work, the three-dimensional quantitative structure-activity relationships of PMH inhibitors were explored and models with good predictive ability were established using comparative molecular field analysis and comparative molecular similarity index analysis methods. The effect of PMH inhibitors' electrostatic potential on the inhibitory ability of Pseudomonas aeruginosa LpxC (PaLpxC) is revealed at the molecular level via molecular electrostatic potential analyses. Then, two molecular dynamics simulations for the PaLpxC and PaLpxC-inhibitor systems were also performed respectively to investigate the key residues of PaLpxC hydrolase binding to water molecules. The results indicate that orderly alternative water molecules can form stable hydrogen bonds with M62, E77, T190, and H264 in the catalytic center, and tetracoordinate to zinc ion along with H78, H237, and D241. It was found that the conformational transition space of PaLpxC changes after association with PMH inhibitors through free energy landscape and cluster analyses. Finally, a possible inhibitory mechanism of PMH inhibitors was proposed, based on our molecular simulation. This paper will provide a theoretical basis for the molecular design of LpxC-targeting antibiotics.

  19. Autophagy inhibitors.

    PubMed

    Pasquier, Benoit

    2016-03-01

    Autophagy is a lysosome-dependent mechanism of intracellular degradation. The cellular and molecular mechanisms underlying this process are highly complex and involve multiple proteins, including the kinases ULK1 and Vps34. The main function of autophagy is the maintenance of cell survival when modifications occur in the cellular environment. During the past decade, extensive studies have greatly improved our knowledge and autophagy has exploded as a research field. This process is now widely implicated in pathophysiological processes such as cancer, metabolic, and neurodegenerative disorders, making it an attractive target for drug discovery. In this review, we will summarize the different types of inhibitors that affect the autophagy machinery and provide some potential therapeutic perspectives.

  20. 4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide - A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation.

    PubMed

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

    2015-08-15

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

  1. A new synthetic matrix metalloproteinase inhibitor reduces human mesenchymal stem cell adipogenesis

    PubMed Central

    Bosco, Dale B.; Roycik, Mark D.; Jin, Yonghao; Schwartz, Martin A.; Lively, Ty J.; Zorio, Diego A. R.

    2017-01-01

    Development of adipose tissue requires the differentiation of less specialized cells, such as human mesenchymal stem cells (hMSCs), into adipocytes. Since matrix metalloproteinases (MMPs) play critical roles in the cell differentiation process, we conducted investigations to determine if a novel mercaptosulfonamide-based MMP inhibitor (MMPI), YHJ-7-52, could affect hMSC adipogenic differentiation and lipid accumulation. Enzyme inhibition assays, adipogenic differentiation experiments, and quantitative PCR methods were employed to characterize this inhibitor and determine its effect upon adipogenesis. YHJ-7-52 reduced lipid accumulation in differentiated cells by comparable amounts as a potent hydroxamate MMPI, GM6001. However, YHJ-7-82, a non-inhibitory structural analog of YHJ-7-52, in which the zinc-binding thiol group is replaced by a hydroxyl group, had no effect on adipogenesis. The two MMPIs (YHJ-7-52 and GM6001) were also as effective in reducing lipid accumulation in differentiated cells as T0070907, an antagonist of peroxisome-proliferator activated receptor gamma (PPAR-gamma), at a similar concentration. PPAR-gamma is a typical adipogenic marker and a key regulatory protein for the transition of preadiopocyte to adipocyte. Moreover, MMP inhibition was able to suppress lipid accumulation in cells co-treated with Troglitazone, a PPAR-gamma agonist. Our results indicate that MMP inhibitors may be used as molecular tools for adipogenesis and obesity treatment research. PMID:28234995

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

    PubMed

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

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

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

  4. Epigenetic Modification Prevents Excessive Wound Healing and Scar Formation After Glaucoma Filtration Surgery.

    PubMed

    Sharma, Ajay; Anumanthan, Govindaraj; Reyes, Marcos; Chen, Huiyi; Brubaker, Jacob W; Siddiqui, Saad; Gupta, Suneel; Rieger, Frank G; Mohan, Rajiv R

    2016-06-01

    The purpose of this study was to determine the efficacy of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor (HDACi), in prevention of excessive wound healing and scar formation in a rabbit model of glaucoma filtration surgery (GFS). A rabbit model of GFS was used. Rabbits that underwent GFS received balanced salt solution, or SAHA (50 μM), or mitomycin C (0.02%). Clinical scores of IOP, bleb vascularity, and slit-lamp examination were performed. On postoperative day 14, rabbits were killed and the bleb tissues were collected for evaluation of tissue fibrosis with hematoxylin and eosin, Masson trichrome, α-smooth muscle actin (αSMA), and F-actin staining. Furthermore, SAHA-mediated acetylation of histones in corneal fibroblasts and conjunctiva were determined by Western blot analysis. Suberoylanilide hydroxamic acid treatment after GFS showed no signs of edema, corneal opacity, endophthalmitis, or cataract formation. Morphometric analysis of SAHA-treated eyes showed higher bleb length (P < 0.001), bleb area (P < 0.05), lower IOP (P < 0.01), and decreased vascularity compared to control. Furthermore, SAHA treatment showed significantly reduced levels of αSMA (P < 0.001), F-actin (P < 0.01), and collagen deposition (P < 0.05) at the sclerotomy site. In addition, SAHA treatment increased the acetylation status of H3 and H4 histones in corneal fibroblasts and conjunctiva. This study demonstrates that HDAC inhibition is an attractive pharmacologic target to modulate GFS wound healing, and SAHA, an HDACi, can be a useful adjunct to improve the GFS outcome.

  5. Phosphinic peptides, the first potent inhibitors of astacin, behave as extremely slow-binding inhibitors.

    PubMed Central

    Yiallouros, I; Vassiliou, S; Yiotakis, A; Zwilling, R; Stöcker, W; Dive, V

    1998-01-01

    A series of phosphinic pseudo-peptides varying in length and composition have been designed as inhibitors of the crayfish zinc endopeptidase astacin, the prototype of the astacin family and of the metzincin superfamily of metalloproteinases. The most efficient phosphinic peptide, fluorenylmethyloxycarbonyl-Pro-Lys-PhePsi(PO2CH2)Ala-P ro-Leu-Val, binds to astacin with a Ki value of 42 nM, which is about three orders of magnitude below the corresponding values for previously used hydroxamic acid derivatives. However, the rate constants for association (kon = 96.8 M-1.s-1) and dissociation (koff = 4.1 x 10(-6) s-1) are evidence for the extremely slow binding behaviour of this compound. N-terminally or C-terminally truncated phosphinic analogues of this parent molecule are much less potent, indicating a critical role of the peptide size on the potency. In particular, omission of the N-terminal proline residue leads to a 40-fold increase in Ki which is mostly due to a 75-fold higher koff value. These findings are consistent with the previously solved crystal structure of astacin complexed with one of the phosphinic peptides, benzyloxycarbonyl-Pro-Lys-PhePsi(PO2CH2)Ala-Pro-O-methyl, Ki = 14 microM [Grams, Dive, Yiotakis, Yiallouros, Vassiliou, Zwilling, Bode and Stöcker (1996) Nature Struct. Biol. 3, 671-675]. This structure also reveals that the phosphinic group binds to the active site as a transition-state analogue. The extremely slow binding behaviour of the phosphinic peptides is discussed in the light of the conformational changes involving a unique 'tyrosine switch' in the structure of astacin upon inhibitor binding. The phosphinic peptides may provide a rational basis for the design of drugs directed towards other members of the astacin family which, like bone morphogenetic protein 1 (BMP1; i.e. the procollagen C-proteinase), have become targets of pharmacological research. PMID:9531473

  6. New bifunctional metalloproteinase inhibitors: an integrated approach towards biological improvements and cancer therapy.

    PubMed

    Marques, Sérgio M; Abate, Claudia C; Chaves, Sílvia; Marques, Fernanda; Santos, Isabel; Nuti, Elisa; Rossello, Armando; Santos, M Amélia

    2013-10-01

    The key role of some matrix metalloproteinases (MMPs) on several pathological processes, including carcinogenesis and tumor growth, makes the development of MMP inhibitors (MMPIs) an attractive approach for cancer therapy. We present herein an integrated approach for the development of a new series of inhibitors of MMP2 and MMP14, two enzymes over-expressed by human ovarian cancer. As a first step, a new series of single model compounds bearing different zinc-binding groups (ZBGs), such as carboxylic, hydroxamic acid, hydrazide and sulfonylhydrazide groups, were studied and revealed reasonably good capacity for the Zn(II) chelation in solution and for the MMP inhibition. Aimed at further reinforcing the biological activity of these MMPIs as anti-cancer agents, a selection of those models was extra-functionalized with benzothiazole (BTA), a group with recognized antitumor activity. Analysis of the results obtained for these bifunctional compounds, in particular the inhibitory activity against MMP2 and MMP14 as well as the anti-proliferative activity on the A2780 ovarian cancer cell line, allowed to understand the activity dependence on the type of ZBG, as well as the relevance of the BTA moiety. Overall, the evidenced BTA-associated activity improvements on enzyme inhibition and cell antiproliferactivity, combined with the hydrolytic stability revealed by the hydrazide group, suggest that these new bifunctional BTA-hydrazide derivatives should be taken in consideration for the development of new generations of MMPIs with anti-cancer activity.

  7. A structure-activity relationship of non-peptide macrocyclic histone deacetylase inhibitors and their anti-proliferative and anti-inflammatory activities.

    PubMed

    Tapadar, Subhasish; Fathi, Shaghayegh; Raji, Idris; Omesiete, Wilson; Kornacki, James R; Mwakwari, Sandra C; Miyata, Masanori; Mitsutake, Kazunori; Li, Jian-Dong; Mrksich, Milan; Oyelere, Adegboyega K

    2015-12-15

    Inhibition of the enzymatic activity of histone deacetylase (HDAC) is a promising therapeutic strategy for cancer treatment and several distinct small molecule histone deacetylase inhibitors (HDACi) have been reported. We have previously identified a new class of non-peptide macrocyclic HDACi derived from 14- and 15-membered macrolide skeletons. In these HDACi, the macrocyclic ring is linked to the zinc chelating hydroxamate moiety through a para-substituted aryl-triazole cap group. To further delineate the depth of the SAR of this class of HDACi, we have synthesized series of analogous compounds and investigated the influence of various substitution patterns on their HDAC inhibitory, anti-proliferative and anti-inflammatory activities. We identified compounds 25b and 38f with robust anti-proliferative activities and compound 26f (IC50 47.2 nM) with superior anti-inflammatory (IC50 88 nM) activity relative to SAHA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  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. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  10. Solution structure of the catalytic domain of human stromelysin complexed with a hydrophobic inhibitor.

    PubMed Central

    Van Doren, S. R.; Kurochkin, A. V.; Hu, W.; Ye, Q. Z.; Johnson, L. L.; Hupe, D. J.; Zuiderweg, E. R.

    1995-01-01

    Stromelysin, a representative matrix metalloproteinase and target of drug development efforts, plays a prominent role in the pathological proteolysis associated with arthritis and secondarily in that of cancer metastasis and invasion. To provide a structural template to aid the development of therapeutic inhibitors, we have determined a medium-resolution structure of a 20-kDa complex of human stromelysin's catalytic domain with a hydrophobic peptidic inhibitor using multinuclear, multidimensional NMR spectroscopy. This domain of this zinc hydrolase contains a mixed beta-sheet comprising one antiparallel strand and four parallel strands, three helices, and a methionine-containing turn near the catalytic center. The ensemble of 20 structures was calculated using, on average, 8 interresidue NOE restraints per residue for the 166-residue protein fragment complexed with a 4-residue substrate analogue. The mean RMS deviation (RMSD) to the average structure for backbone heavy atoms is 0.91 A and for all heavy atoms is 1.42 A. The structure has good stereochemical properties, including its backbone torsion angles. The beta-sheet and alpha-helices of the catalytic domains of human stromelysin (NMR model) and human fibroblast collagenase (X-ray crystallographic model of Lovejoy B et al., 1994b, Biochemistry 33:8207-8217) superimpose well, having a pairwise RMSD for backbone heavy atoms of 2.28 A when three loop segments are disregarded. The hydroxamate-substituted inhibitor binds across the hydrophobic active site of stromelysin in an extended conformation. The first hydrophobic side chain is deeply buried in the principal S'1 subsite, the second hydrophobic side chain is located on the opposite side of the inhibitor backbone in the hydrophobic S'2 surface subsite, and a third hydrophobic side chain (P'3) lies at the surface. PMID:8580839

  11. Characterisation of the in vitro activity of the depsipeptide histone deacetylase inhibitor spiruchostatin A.

    PubMed

    Crabb, Simon J; Howell, Melanie; Rogers, Helen; Ishfaq, Muhammad; Yurek-George, Alexander; Carey, Krystle; Pickering, Becky M; East, Phil; Mitter, Richard; Maeda, Satoko; Johnson, Peter W M; Townsend, Paul; Shin-ya, Kazuo; Yoshida, Minoru; Ganesan, A; Packham, Graham

    2008-08-15

    We recently completed the total synthesis of spiruchostatin A, a depsipeptide natural product with close structural similarities to FK228, a histone deacetylase (HDAC) inhibitor (HDI) currently being evaluated in clinical trials for cancer. Here we report a detailed characterisation of the in vitro activity of spiruchostatin A. Spiruchostatin A was a potent (sub-nM) inhibitor of class I HDAC activity in vitro and acted as a prodrug, requiring reduction for activity. Spiruchostatin A was a potent (low nM) inhibitor of the growth of various cancer cell lines. Spiruchostatin A-induced acetylation of specific lysine residues within histones H3 and H4, and increased the expression of p21(cip1/waf1), but did not induce acetylation of alpha-tubulin. Spiruchostatin A also induced cell cycle arrest, differentiation and cell death in MCF7 breast cancer cells. Like FK228, spiruchostatin A was both an inducer and substrate of the ABCB1 drug efflux pump. Whereas spiruchostatin A and FK228-induced protracted histone acetylation, hydroxamate HDI-induced short-lived histone acetylation. Using a subset of HDI-target genes identified by microarray analysis, we demonstrated that these differences in kinetics of histone acetylation between HDI correlated with differences in the kinetics of induction or repression of specific target genes. Our results demonstrate that spiruchostatin A is a potent inhibitor of class I HDACs and anti-cancer agent. Differences in the kinetics of action of HDI may be important for the clinical application of these compounds.

  12. Forward and reverse (retro) iron(III) or gallium(III) desferrioxamine E and ring-expanded analogues prepared using metal-templated synthesis from endo-hydroxamic acid monomers.

    PubMed

    Lifa, Tulip; Tieu, William; Hocking, Rosalie K; Codd, Rachel

    2015-04-06

    A metal-templated synthesis (MTS) approach was used to preorganize the forward endo-hydroxamic acid monomer 4-[(5-aminopentyl)(hydroxy)amino]-4-oxobutanoic acid (for-PBH) about iron(III) in a 1:3 metal/ligand ratio to furnish the iron(III) siderophore for-[Fe(DFOE)] (ferrioxamine E) following peptide coupling. Substitution of for-PBH with the reverse (retro) hydroxamic acid analogue 3-(6-amino-N-hydroxyhexanamido)propanoic acid (ret-PBH) furnished ret-[Fe(DFOE)] (ret-ferrioxamine E). As isomers, for-[Fe(DFOE)] and ret-[Fe(DFOE)] gave identical mass spectrometry signals ([M + H(+)](+), m/zcalc 654.3, m/zobs 654.3), yet for-[Fe(DFOE)] eluted in a more polar window (tR = 23.44 min) than ret-[Fe(DFOE)] (tR = 28.13 min) on a C18 reverse-phase high-performance liquid chromatography (RP-HPLC) column. for-[Ga(DFOE)] (tR = 22.99 min) and ret-[Ga(DFOE)] (tR = 28.11 min) were prepared using gallium(III) as the metal-ion template and showed the same trend for the retention time. Ring-expanded analogues of for-[Fe(DFOE)] and ret-[Fe(DFOE)] were prepared from endo-hydroxamic acid monomers with one additional methylene unit in the amine-containing region, 4-[(6-aminohexyl)(hydroxy)amino]-4-oxobutanoic acid (for-HBH) or 3-(7-amino-N-hydroxyheptanamido)propanoic acid (ret-HBH), to give the corresponding tris(homoferrioxamine E) macrocycles, for-[Fe(HHDFOE)] or ret-[Fe(HHDFOE)] ([M + H(+)](+), m/zcalc 696.3, m/zobs 696.4). The MTS reaction using a constitutional isomer of for-HBH that transposed the methylene unit to the carboxylic acid containing region, 5-[(5-aminopentyl)(hydroxy)amino]-5-oxopentanoic acid (for-PPH), gave the macrocycle for-[Fe(HPDFOE)] in a yield significantly less than that for for-[Fe(HHDFOE)], with the gallium(III) analogue for-[Ga(HPDFOE)] unable to be detected. The work demonstrates the utility and limits of MTS for the assembly of macrocyclic siderophores from endo-hydroxamic acid monomers. Indirect measures (RP-HPLC order of elution, c log P values

  13. Drug forecast – the peptide deformylase inhibitors as antibacterial agents

    PubMed Central

    Guay, David R P

    2007-01-01

    The relatively rapid development of microbial resistance after the entry of every new antimicrobial into the marketplace necessitates a constant supply of new agents to maintain effective pharmacotherapy. Despite extensive efforts to identify novel lead compounds from molecular targets, only the peptide deformylase inhibitors (PDIs) have shown any real promise, with some advancing to phase I human trials. Bacterial peptide deformylase, which catalyzes the removal of the N-formyl group from N-terminal methionine following translation, is essential for bacterial protein synthesis, growth, and survival. The majority of PDIs are pseudopeptide hydroxamic acids and two of these (IV BB-83698 and oral NVP LBM-415) entered phase I human trials. However, agents to the present have suffered from major potential liabilities. Their in vitro activity has been limited to gram-positive aerobes and some anaerobes and has been quite modest against the majority of such species (MIC90 values ranging from 1–8 mg/L). They have exerted bacteriostatic, not bacteriocidal, activity, thus reducing their potential usefulness in the management of serious infections in the immunocompromised. The relative ease with which microorganisms have been able to develop resistance and the multiple available mechanisms of resistance (mutations in fmt, defB, folD genes; AcrAB/TolC efflux pump; overexpression of peptide deformylase) are worrisome. These could portend a short timespan of efficacy after marketing. Despite these current liabilities, further pursuit of more potent and broader spectrum PDIs which are less susceptible to bacterial mechanisms of resistance is still warranted. PMID:18472972

  14. Acquired Factor V Inhibitor

    PubMed Central

    Hirai, Daisuke; Yamashita, Yugo; Masunaga, Nobutoyo; Katsura, Toshiaki; Akao, Masaharu; Okuno, Yoshiaki; Koyama, Hiroshi

    2016-01-01

    Inhibitors directed against factor V rarely occur, and the clinical symptoms vary. We herein report the case of a patient who presented with a decreased factor V activity that had decreased to <3 %. We administered vitamin K and 6 units of fresh frozen plasma, but she thereafter developed an intracerebral hemorrhage. It is unclear whether surgery >10 years earlier might have caused the development of a factor V inhibitor. The treatment of acquired factor V inhibitors is mainly the transfusion of platelet concentrates and corticosteroids. Both early detection and the early initiation of the treatment of factor V inhibitor are thus considered to be important. PMID:27746446

  15. Inhibitors of Pyruvate Carboxylase

    PubMed Central

    Zeczycki, Tonya N.; Maurice, Martin St.; Attwood, Paul V.

    2010-01-01

    This review aims to discuss the varied types of inhibitors of biotin-dependent carboxylases, with an emphasis on the inhibitors of pyruvate carboxylase. Some of these inhibitors are physiologically relevant, in that they provide ways of regulating the cellular activities of the enzymes e.g. aspartate and prohibitin inhibition of pyruvate carboxylase. Most of the inhibitors that will be discussed have been used to probe various aspects of the structure and function of these enzymes. They target particular parts of the structure e.g. avidin – biotin, FTP – ATP binding site, oxamate – pyruvate binding site, phosphonoacetate – binding site of the putative carboxyphosphate intermediate. PMID:22180764

  16. Synthesis and biological evaluation of flexible and conformationally constrained LpxC inhibitors.

    PubMed

    Löppenberg, Marius; Müller, Hannes; Pulina, Carla; Oddo, Alberto; Teese, Mark; Jose, Joachim; Holl, Ralph

    2013-09-28

    Inhibitors of the UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase (LpxC) represent promising candidates for the development of antibiotics possessing a so far unexploited mechanism of action. In a chiral pool synthesis, starting from the D-mannose derived mannonolactone 4, conformationally constrained C-glycosidic as well as open chained hydroxamic acids with a defined stereochemistry were prepared. Diversity was introduced by performing C–C coupling reactions like the Sonogashira and Suzuki cross-coupling reactions. The biological evaluation of the synthesized compounds revealed that in the case of the C-glycosides a long, linear and rigid hydrophobic side chain is required for antibiotic activity against E. coli. The open chain derivatives show higher biological activity than the conformationally constrained C-glycosides. The morpholinomethyl substituted open chain derivative 43, being the most potent compound presented in this paper, inhibits LpxC with a Ki value of 0.35 μM and represents a promising lead structure.

  17. Novel inhibitors of urokinase-type plasminogen activator and matrix metalloproteinase expression in metastatic cancer cell lines.

    PubMed

    Cakarovski, Kristina; Leung, Jenny Y; Restall, Christina; Carin-Carlson, Anna; Yang, Eunice; Perlmutter, Patrick; Anderson, Robin; Medcalf, Robert; Dear, Anthony E

    2004-07-01

    The plasminogen-activating (PA) and matrix metalloproteinase (MMP) enzyme systems are implicated in proteolytic turnover of the extracellular matrix (ECM) associated with biologic processes including wound healing, inflammation and angiogenesis. Aberrant expression of components of the PA and MMP enzyme systems occurs in the pathogenesis of metastatic cancer. Oxamflatin (Ox), a novel hydroxamic acid derivative, inhibits u-PA mRNA expression and proteolytic activity while simultaneously upregulating the expression of the natural inhibitor of u-PA, plasminogen activator inhibitor type 2 (PAI-2) in metastatic cancer cells. We have characterized the effects of Ox and a novel derivative, Metacept-1 (MCT-1), on PA and MMP-mediated proteolysis and invasion in several metastatic tumor lines. Both compounds are able to inhibit u-PA-, MMP-2- and MMP-9-mediated gene expression at low micromolar concentrations as well as u-PA- and MMP-mediated proteolysis as assessed by zymography, with MCT-1 being the more effective of the 2 agents in some assays. Cellular invasion assays correlate with gene expression and zymography experiments identifying both Ox and MCT-1 as able to inhibit invasion of metastatic cancer cell lines through matrigel at nanomolar concentrations, with MCT-1 more effective than Ox in 2 of the 3 cancer cell lines assessed.

  18. Phase I/II study of docetaxel combined with resminostat, an oral hydroxamic acid HDAC inhibitor, for advanced non-small cell lung cancer in patients previously treated with platinum-based chemotherapy.

    PubMed

    Tambo, Yuichi; Hosomi, Yukio; Sakai, Hiroshi; Nogami, Naoyuki; Atagi, Shinji; Sasaki, Yasutsuna; Kato, Terufumi; Takahashi, Toshiaki; Seto, Takashi; Maemondo, Makoto; Nokihara, Hiroshi; Koyama, Ryo; Nakagawa, Kazuhiko; Kawaguchi, Tomoya; Okamura, Yuta; Nakamura, Osamu; Nishio, Makoto; Tamura, Tomohide

    2017-04-01

    Objectives To determine the recommended dose and efficacy/safety of docetaxel combined with resminostat (DR) in non-small cell lung cancer (NSCLC) patients with previous platinum-based chemotherapy. Materials and Methods A multicenter, open-label, phase I/II study was performed in Japanese patients with stage IIIB/IV or recurrent NSCLC and prior platinum-based chemotherapy. The recommended phase II dose was determined using a standard 3 + 3 dose design in phase I part. Resminostat was escalated from 400 to 600 mg/day and docetaxel fixed at 75 mg/m(2). In phase II part, the patients were randomly assigned to docetaxel alone (75 mg/m(2)) or DR therapy. Docetaxel was administered on day 1 and resminostat on days 1-5 in the DR group. Treatment was repeated every 21 days until progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Results A total of 117 patients (phase I part, 9; phase II part, 108) were enrolled. There was no dose-limiting toxicity in phase I part; the recommended dose for resminostat was 600 mg/day with 75 mg/m(2) of docetaxel. In phase II part, median PFS (95% confidence interval [CI]) was 4.2 (2.8-5.7) months with docetaxel group and 4.1 (1.5-5.4) months with DR group (hazard ratio [HR]: 1.354, 95% CI: 0.835-2.195; p = 0.209). Grade ≥ 3 adverse events significantly more common with DR group than docetaxel group were leukopenia, febrile neutropenia, thrombocytopenia, and anorexia. Conclusion In Japanese NSCLC patients previously treated with platinum-based chemotherapy, DR therapy did not improve PFS compared with docetaxel alone and increased toxicity.

  19. Novel corrosion inhibitor technology

    SciTech Connect

    Van de Ven, P.; Fritz, P.; Pellet, R.

    1999-11-01

    A novel, patented corrosion inhibitor technology has been identified for use in heat transfer applications such as automotive and heavy-duty coolant. The new technology is based on a low-toxic, virtually depletion-free carboxylic acid corrosion inhibitor package that performs equally well in mono ethylene glycol and in less toxic propylene glycol coolants. An aqueous inhibitor concentrate is available to provide corrosion protection where freezing protection is not an issue. In the present paper, this inhibitor package is evaluated in the different base fluids: mono ethylene glycol, mono propylene glycol and water. Results are obtained in both standardized and specific corrosion tests as well as in selected field trials. These results indicate that the inhibitor package remains effective and retains the benefits previously identified in automotive engine coolant applications: excellent corrosion protection under localized conditions, general corrosion conditions as well as at high temperature.

  20. Disarming an Electrophilic Warhead: Retaining Potency in Tyrosine Kinase Inhibitor (TKI)-Resistant CML Lines While Circumventing Pharmacokinetic Liabilities.

    PubMed

    Ali, Ahmed M; Gómez-Biagi, Rodolfo F; Rosa, David A; Lai, Ping-Shan; Heaton, William L; Park, Ji Sung; Eiring, Anna M; Vellore, Nadeem A; de Araujo, Elvin D; Ball, Dan P; Shouksmith, Andrew E; Patel, Ami B; Deininger, Michael W; O'Hare, Thomas; Gunning, Patrick T

    2016-04-19

    Pharmacologic blockade of the activation of signal transducer and activator of transcription 3 (STAT3) in tyrosine kinase inhibitor (TKI)-resistant chronic myeloid leukemia (CML) cell lines characterized by kinase-independent resistance was shown to re-sensitize CML cells to TKI therapy, suggesting that STAT3 inhibitors in combination with TKIs are an effective combinatorial therapeutic for the treatment of CML. Benzoic acid- and hydroxamic acid-based STAT3 inhibitors SH-4-054 and SH-5-007, developed previously in our laboratory, demonstrated promising activity against these resistant CML cell lines. However, pharmacokinetic studies in murine models (CD-1 mice) revealed that both SH-4-054 and SH-5-007 are susceptible to glutathione conjugation at the para position of the pentafluorophenyl group via nucleophilic aromatic substitution (SN Ar). To determine whether the electrophilicity of the pentafluorophenyl sulfonamide could be tempered, an in-depth structure-activity relationship (SAR) study of the SH-4-054 scaffold was conducted. These studies revealed that AM-1-124, possessing a 2,3,5,6-tetrafluorophenylsulfonamide group, retained STAT3 protein affinity (Ki =15 μm), as well as selectivity over STAT1 (Ki >250 μm). Moreover, in both hepatocytes and in in vivo pharmacokinetic studies (CD-1 mice), AM-1-124 was found to be dramatically more stable than SH-4-054 (t1/2 =1.42 h cf. 10 min, respectively). AM-1-124 is a promising STAT3-targeting inhibitor with demonstrated bioavailability, suitable for evaluation in preclinical cancer models.

  1. CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR

    PubMed Central

    Kunitz, M.

    1947-01-01

    A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.5. It inhibits the proteolytic action approximately of an equal weight of crystalline trypsin by combining with trypsin to form a stable compound. Chymotrypsin is only slightly inhibited by soy inhibitor. The reaction between chymotrypsin and the soy inhibitor consists in the formation of a reversibly dissociable compound. The inhibitor has no effect on pepsin. The inhibiting action of the soybean inhibitor is associated with the native state of the protein molecule. Denaturation of the soy protein by heat or acid or alkali brings about a proportional decrease in its inhibiting action on trypsin. Reversal of denaturation results in a proportional gain in the inhibiting activity. Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin. Methods are given for measuring trypsin and inhibitor activity and also protein concentration with the aid of spectrophotometric density measurements at 280 mµ. PMID:19873496

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

    PubMed

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

    2016-02-01

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

  3. Complexation of desferricoprogen with trivalent Fe, Al, Ga, In and divalent Fe, Ni, Cu, Zn metal ions: effects of the linking chain structure on the metal binding ability of hydroxamate based siderophores.

    PubMed

    Enyedy, Eva A; Pócsi, István; Farkas, Etelka

    2004-11-01

    Complexes of the natural siderophore, desferricoprogen (DFC), with several trivalent and divalent metal ions in aqueous solution were studied by pH-potentiometry, UV-Vis spectrophotometry and cyclic voltammetry. DFC was found to be an effective metal binding ligand, which, in addition to Fe(III), forms complexes of high stability with Ga(III), Al(III), In(III), Cu(II), Ni(II) and Zn(II). Fe(II), however, is oxidized by DFC under anaerobic conditions and Fe(III) complexes are formed. By comparing the results with those of desferrioxamine B (DFB), it can be concluded that the conjugated beta-double bond slightly increases the stability of the hydroxamate chelates, consequently increases the stability of mono-chelated complexes of DFC. Any steric effect by the connecting chains arises only in the bis- and tris-chelated complexes. With metal ions possessing a relatively big ionic radius (Cu(II), Ni(II), Zn(II), In(III)) DFC, containing a bit longer chains than DFB, forms slightly more stable complexes. With smaller metal ions the trend is the opposite. Also a notable difference is that stable trinuclear complex, [Cu(3)L(2)], is formed with DFC but not with DFB. Possible bio-relevance of the Fe(II)/Fe(III) results is also discussed in the paper.

  4. Novel biologically based therapies for Waldenstrom's macroglobulinemia.

    PubMed

    Mitsiades, Constantine S; Mitsiades, Nicholas; Richardson, Paul G; Treon, Steven P; Anderson, Kenneth C

    2003-04-01

    Waldenstrom's macroglobulinemia (WM) remains an incurable B-cell malignancy, necessitating urgent development of novel treatment strategies. Building on our experience on bed-to-bedside translational studies for multiple myeloma (mm), we identified a constellation of novel classes of anti-WM agents, including the proteasome inhibitor PS-341; the ansamycin family of inhibitors (eg, geldanamycin and its analogues) of the heat-shock protein 90 (hsp90) molecular chaperone; histone deacetylase inhibitors, such as suberoylanilide hydroxamic acid (SAHA); and the thiazolidinedione group of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists (eg, ciglitazone or rosiglitazone). Our preclinical data show that these classes of agents induce growth arrest and apoptosis of WM cells, at concentrations relevant to those achieved in previous clinical uses of these drugs, and suggest that novel therapeutic strategies for WM can be designed to include combinations of these agents, to simultaneously target multiple levels of diverse pathways important for tumor cell growth and survival, and thus maximize the pro-apoptotic activities of these agents and/or neutralize protective responses of WM against their effects. These molecular studies provide a framework for rational design of the next generation of combination therapies for WM. Copyright 2003 Elsevier Inc. All rights reserved.

  5. SCL/TAL1-mediated Transcriptional Network Enhances Megakaryocytic Specification of Human Embryonic Stem Cells

    PubMed Central

    Toscano, Miguel G; Navarro-Montero, Oscar; Ayllon, Veronica; Ramos-Mejia, Veronica; Guerrero-Carreno, Xiomara; Bueno, Clara; Romero, Tamara; Lamolda, Mar; Cobo, Marien; Martin, Francisco; Menendez, Pablo; Real, Pedro J

    2015-01-01

    Human embryonic stem cells (hESCs) are a unique in vitro model for studying human developmental biology and represent a potential source for cell replacement strategies. Platelets can be generated from cord blood progenitors and hESCs; however, the molecular mechanisms and determinants controlling the in vitro megakaryocytic specification of hESCs remain elusive. We have recently shown that stem cell leukemia (SCL) overexpression accelerates the emergence of hemato-endothelial progenitors from hESCs and promotes their subsequent differentiation into blood cells with higher clonogenic potential. Given that SCL participates in megakaryocytic commitment, we hypothesized that it may potentiate megakaryopoiesis from hESCs. We show that ectopic SCL expression enhances the emergence of megakaryocytic precursors, mature megakaryocytes (MKs), and platelets in vitro. SCL-overexpressing MKs and platelets respond to different activating stimuli similar to their control counterparts. Gene expression profiling of megakaryocytic precursors shows that SCL overexpression renders a megakaryopoietic molecular signature. Connectivity Map analysis reveals that trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), both histone deacetylase (HDAC) inhibitors, functionally mimic SCL-induced effects. Finally, we confirm that both TSA and SAHA treatment promote the emergence of CD34+ progenitors, whereas valproic acid, another HDAC inhibitor, potentiates MK and platelet production. We demonstrate that SCL and HDAC inhibitors are megakaryopoiesis regulators in hESCs. PMID:25292191

  6. Combinatorial Treatment of DNA and Chromatin-Modifying Drugs Cause Cell Death in Human and Canine Osteosarcoma Cell Lines

    PubMed Central

    Thayanithy, Venugopal; Park, ChangWon; Sarver, Aaron L.; Kartha, Reena V.; Korpela, Derek M.; Graef, Ashley J.; Steer, Clifford J.; Modiano, Jaime F.; Subramanian, Subbaya

    2012-01-01

    Downregulation of microRNAs (miRNAs) at the 14q32 locus stabilizes the expression of cMYC, thus significantly contributing to osteosarcoma (OS) pathobiology. Here, we show that downregulation of 14q32 miRNAs is epigenetically regulated. The predicted promoter regions of miRNA clusters at 14q32 locus showed no recurrent patterns of differential methylation, but Saos2 cells showed elevated histone deacetylase (HDAC) activity. Treatment with 4-phenylbutyrate increased acetylation of histones associated with 14q32 miRNAs, but interestingly, robust restoration of 14q32 miRNA expression, attenuation of cMYC expression, and induction of apoptosis required concomitant treatment with 5-Azacytidine, an inhibitor of DNA methylation. These events were associated with genome-wide gene expression changes including induction of pro-apoptotic genes and downregulation of cell cycle genes. Comparable effects were achieved in human and canine OS cells using the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA/Vorinostat) and the DNA methylation inhibitor Zebularine (Zeb), with significantly more pronounced cytotoxicity in cells whose molecular phenotypes were indicative of aggressive biological behavior. These results suggested that the combination of these chromatin-modifying drugs may be a useful adjuvant in the treatment of rapidly progressive OS. PMID:22957032

  7. SCL/TAL1-mediated transcriptional network enhances megakaryocytic specification of human embryonic stem cells.

    PubMed

    Toscano, Miguel G; Navarro-Montero, Oscar; Ayllon, Veronica; Ramos-Mejia, Veronica; Guerrero-Carreno, Xiomara; Bueno, Clara; Romero, Tamara; Lamolda, Mar; Cobo, Marien; Martin, Francisco; Menendez, Pablo; Real, Pedro J

    2015-01-01

    Human embryonic stem cells (hESCs) are a unique in vitro model for studying human developmental biology and represent a potential source for cell replacement strategies. Platelets can be generated from cord blood progenitors and hESCs; however, the molecular mechanisms and determinants controlling the in vitro megakaryocytic specification of hESCs remain elusive. We have recently shown that stem cell leukemia (SCL) overexpression accelerates the emergence of hemato-endothelial progenitors from hESCs and promotes their subsequent differentiation into blood cells with higher clonogenic potential. Given that SCL participates in megakaryocytic commitment, we hypothesized that it may potentiate megakaryopoiesis from hESCs. We show that ectopic SCL expression enhances the emergence of megakaryocytic precursors, mature megakaryocytes (MKs), and platelets in vitro. SCL-overexpressing MKs and platelets respond to different activating stimuli similar to their control counterparts. Gene expression profiling of megakaryocytic precursors shows that SCL overexpression renders a megakaryopoietic molecular signature. Connectivity Map analysis reveals that trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), both histone deacetylase (HDAC) inhibitors, functionally mimic SCL-induced effects. Finally, we confirm that both TSA and SAHA treatment promote the emergence of CD34(+) progenitors, whereas valproic acid, another HDAC inhibitor, potentiates MK and platelet production. We demonstrate that SCL and HDAC inhibitors are megakaryopoiesis regulators in hESCs.

  8. Catalytic activity and inhibition of human histone deacetylase 8 is dependent on the identity of the active site metal ion.

    PubMed

    Gantt, Stephanie L; Gattis, Samuel G; Fierke, Carol A

    2006-05-16

    Histone deacetylases play a key role in regulating transcription and other cellular processes by catalyzing the hydrolysis of epsilon-acetyl-lysine residues. For this reason, inhibitors of histone deacetylases are potential targets for the treatment of cancer. A subset of these enzymes has previously been shown to require divalent metal ions for catalysis. Here we demonstrate that histone deacetylase 8 (HDAC8) is catalytically active with a number of divalent metal ions in a 1:1 stoichiometry with the following order of specific activity: Co(II) > Fe(II) > Zn(II) > Ni(II). The identity of the catalytic metal ion influences both the affinity of the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and the Michaelis constant, with Fe(II)- and Co(II)-HDAC8 having K(M) values that are over 5-fold lower than that of Zn(II)-HDAC8. These data suggest that Fe(II), rather than Zn(II), may be the in vivo catalytic metal. In further support of this hypothesis, recombinant HDAC8 purified from E. coli contains 8-fold more iron than zinc before dialysis, and the HDAC8 activity in cell lysates is oxygen-sensitive. Identification of the in vivo metal ion of HDAC8 is essential for understanding the biological function and regulation of HDAC8 and for the development of improved inhibitors of this class of enzymes.

  9. Metalloproteinase inhibitors for the disintegrin-like metalloproteinases ADAM10 and ADAM17 that differentially block constitutive and phorbol ester-inducible shedding of cell surface molecules.

    PubMed

    Ludwig, Andreas; Hundhausen, Christian; Lambert, Millard H; Broadway, Neil; Andrews, Robert C; Bickett, D Mark; Leesnitzer, M Anthony; Becherer, J David

    2005-03-01

    The transmembrane metzinkin-proteases of the ADAM (a disintegrin and a metalloproteinase)-family ADAM10 and ADAM 17 are both implicated in the ectodomain shedding of various cell surface molecules including the IL6-receptor and the transmembrane chemokines CX3CL1 and CXCL16. These molecules are constitutively released from cultured cells, a process that can be rapidly enhanced by cell stimulation with phorbol esters such as PMA. Recent research supports the view that the constitutive cleavage predominantly involves ADAM10 while the inducible one is mediated to a large extent by ADAM17. We here describe the discovery of hydroxamate compounds with different potency against ADAM10 and ADAM17 and different ability to block constitutive and inducible cleavage of IL6R, CX3CL1 and CXCL16 by the two proteases. By screening a number of hydroxamate inhibitors for the inhibition of recombinant metalloproteinases, a compound was found inhibiting ADAM10 with more than 100-fold higher potency than ADAM17, which may be explained by an improved fit of the compound to the S1' specificity pocket of ADAM10 as compared to that of ADAM17. In cell-based cleavage experiments this compound (GI254023X) potently blocked the constitutive release of IL6R, CX3CL1 and CXCL16, which was in line with the reported involvement of ADAM10 but not ADAM17 in this process. By contrast, the compound did not affect the PMA-induced shedding, which was only blocked by GW280264X, a potent inhibitor of ADAM17. As expected, GI254023X did not further decrease the residual release of CX3CL1 and CXCL16 in ADAM10-deficient cells verifying that the compound's effect on the constitutive shedding of these molecules was exclusively due to the inhibition of ADAM10. Thus, GI254023X may by of use as a preferential inhibitor of constitutive shedding events without effecting the inducible shedding in response to agonists acting similar to PMA.

  10. Natural inhibitors of thrombin.

    PubMed

    Huntington, James A

    2014-04-01

    The serine protease thrombin is the effector enzyme of blood coagulation. It has many activities critical for the formation of stable clots, including cleavage of fibrinogen to fibrin, activation of platelets and conversion of procofactors to active cofactors. Thrombin carries-out its multiple functions by utilising three special features: a deep active site cleft and two anion binding exosites (exosite I and II). Similarly, thrombin inhibitors have evolved to exploit the unique features of thrombin to achieve rapid and specific inactivation of thrombin. Exogenous thrombin inhibitors come from several different protein families and are generally found in the saliva of haematophagous animals (blood suckers) as part of an anticoagulant cocktail that allows them to feed. Crystal structures of several of these inhibitors reveal how peptides and proteins can be targeted to thrombin in different and interesting ways. Thrombin activity must also be regulated by endogenous inhibitors so that thrombi do not occlude blood flow and cause thrombosis. A single protein family, the serpins, provides all four of the endogenous thrombin inhibitors found in man. The crystal structures of these serpins bound to thrombin have been solved, revealing a similar exosite-dependence on complex formation. In addition to forming the recognition complex, serpins destroy the structure of thrombin, allowing them to be released from cofactors and substrates for clearance. This review examines how the special features of thrombin have been exploited by evolution to achieve inhibition of the ultimate coagulation protease.

  11. [Acquired coagulant factor inhibitors].

    PubMed

    Nogami, Keiji

    2015-02-01

    Acquired coagulation factor inhibitors are an autoimmune disease causing bleeding symptoms due to decreases in the corresponding factor (s) which result from the appearance of autoantibodies against coagulation factors (inhibitor). This disease is quite different from congenital coagulation factor deficiencies based on genetic abnormalities. In recent years, cases with this disease have been increasing, and most have anti-factor VIII autoantibodies. The breakdown of the immune control mechanism is speculated to cause this disease since it is common in the elderly, but the pathology and pathogenesis are presently unclear. We herein describe the pathology and pathogenesis of factor VIII and factor V inhibitors. Characterization of these inhibitors leads to further analysis of the coagulation process and the activation mechanisms of clotting factors. In the future, with the development of new clotting examination method (s), we anticipate that further novel findings will be obtained in this field through inhibitor analysis. In addition, detailed elucidation of the coagulation inhibitory mechanism possibly leading to hemostatic treatment strategies for acquired coagulation factor disorders will be developed.

  12. SGLT2 inhibitors.

    PubMed

    Dardi, I; Kouvatsos, T; Jabbour, S A

    2016-02-01

    Diabetes mellitus is a serious health issue and an economic burden, rising in epidemic proportions over the last few decades worldwide. Although several treatment options are available, only half of the global diabetic population achieves the recommended or individualized glycemic targets. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic agents with a novel insulin-independent action. SGLT2 is a transporter found in the proximal renal tubules, responsible for the reabsorption of most of the glucose filtered by the kidney. Inhibition of SGLT2 lowers the blood glucose level by promoting the urinary excretion of excess glucose. Due to their insulin-independent action, SGLT2 inhibitors can be used with any degree of beta-cell dysfunction or insulin resistance, related to a very low risk of hypoglycemia. In addition to improving glycemic control, SGLT2 inhibitors have been associated with a reduction in weight and blood pressure when used as monotherapy or in combination with other antidiabetic agents in patients with type 2 diabetes mellitus (T2DM). Treatment with SGLT2 inhibitors is usually well tolerated; however, they have been associated with an increased incidence of urinary tract and genital infections, although these infections are usually mild and easy to treat. SGLT2 inhibitors are a promising new option in the armamentarium of drugs for patients with T2DM.

  13. Cholinesterase inhibitors from botanicals

    PubMed Central

    Ahmed, Faiyaz; Ghalib, Raza Murad; Sasikala, P.; Ahmed, K. K. Mueen

    2013-01-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh), appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com) are also presented and the scope for future research is discussed. PMID:24347920

  14. Synthesis and biological characterization of spiro[2H-(1,3)-benzoxazine-2,4'-piperidine] based histone deacetylase inhibitors.

    PubMed

    Thaler, Florian; Varasi, Mario; Abate, Agnese; Carenzi, Giacomo; Colombo, Andrea; Bigogno, Chiara; Boggio, Roberto; Zuffo, Roberto Dal; Rapetti, Daniela; Resconi, Anna; Regalia, Nickolas; Vultaggio, Stefania; Dondio, Giulio; Gagliardi, Stefania; Minucci, Saverio; Mercurio, Ciro

    2013-06-01

    Histone Deacetylases (HDACs) have become important targets for the treatment of cancer and other diseases. In previous studies we described the development of novel spirocyclic HDAC inhibitors based on the combination of privileged structures with hydroxamic acid moieties as zinc binding group. Herein, we report further explorations, which resulted in the discovery of a new class of spiro[2H-(1,3)-benzoxazine-2,4'-piperidine] derivatives. Several compounds showed good potency of around 100 nM and less in the HDAC inhibition assays, submicromolar IC50 values when tested against tumour cell lines and a remarkable stability in human and mouse microsomes. Two representative examples exhibited a good pharmacokinetic profile with an oral bioavailability equal or higher than 35% and one of them studied in an HCT116 murine xenograft model showing a robust tumour growth inhibition. In addition, the two benzoxazines were found to have a minor affinity for the hERG potassium channel compared to their corresponding ketone analogues.

  15. Preclinical Pharmacokinetics Study of R- and S-Enantiomers of the Histone Deacetylase Inhibitor, AR-42 (NSC 731438), in Rodents.

    PubMed

    Cheng, Hao; Xie, Zhiliang; Jones, William P; Wei, Xiaohui Tracey; Liu, Zhongfa; Wang, Dasheng; Kulp, Samuel K; Wang, Jiang; Coss, Christopher C; Chen, Ching-Shih; Marcucci, Guido; Garzon, Ramiro; Covey, Joseph M; Phelps, Mitch A; Chan, Kenneth K

    2016-05-01

    AR-42, a new orally bioavailable, potent, hydroxamate-tethered phenylbutyrate class I/IIB histone deacetylase inhibitor currently is under evaluation in phase 1 and 2 clinical trials and has demonstrated activity in both hematologic and solid tumor malignancies. This report focuses on the preclinical characterization of the pharmacokinetics of AR-42 in mice and rats. A high-performance liquid chromatography-tandem mass spectrometry assay has been developed and applied to the pharmacokinetic study of the more active stereoisomer, S-AR-42, when administered via intravenous and oral routes in rodents, including plasma, bone marrow, and spleen pharmacokinetics (PK) in CD2F1 mice and plasma PK in F344 rats. Oral bioavailability was estimated to be 26 and 100% in mice and rats, respectively. R-AR-42 was also evaluated intravenously in rats and was shown to display different pharmacokinetics with a much shorter terminal half-life compared to that of S-AR-42. Renal clearance was a minor elimination pathway for parental S-AR-42. Oral administration of S-AR-42 to tumor-bearing mice demonstrated high uptake and exposure of the parent drug in the lymphoid tissues, spleen, and bone marrow. This is the first report of the pharmacokinetics of this novel agent, which is now in early phase clinical trials.

  16. Design, synthesis, and biological evaluation of novel matrix metalloproteinase inhibitors as potent antihemorrhagic agents: from hit identification to an optimized lead.

    PubMed

    Orbe, Josune; Sánchez-Arias, Juan A; Rabal, Obdulia; Rodríguez, José A; Salicio, Agustina; Ugarte, Ana; Belzunce, Miriam; Xu, Musheng; Wu, Wei; Tan, Haizhong; Ma, Hongyu; Páramo, José A; Oyarzabal, Julen

    2015-03-12

    Growing evidence suggests that matrix metalloproteinases (MMP) are involved in thrombus dissolution; then, considering that new therapeutic strategies are required for controlling hemorrhage, we hypothesized that MMP inhibition may reduce bleeding by delaying fibrinolysis. Thus, we designed and synthesized a novel series of MMP inhibitors to identify potential candidates for acute treatment of bleeding. Structure-based and knowledge-based strategies were utilized to design this novel chemical series, α-spiropiperidine hydroxamates, of potent and soluble (>75 μg/mL) pan-MMP inhibitors. The initial hit, 12, was progressed to an optimal lead 19d. Racemic 19d showed a remarkable in vitro phenotypic response and outstanding in vivo efficacy; in fact, the mouse bleeding time at 1 mg/kg was 0.85 min compared to 29.28 min using saline. In addition, 19d displayed an optimal ADME and safety profile (e.g., no thrombus formation). Its corresponding enantiomers were separated, leading to the preclinical candidate 5 (described in Drug Annotations series, J. Med. Chem. 2015, ).

  17. Propioxatins A and B, new enkephalinase B inhibitors. IV. Characterization of the active site of the enzyme using synthetic propioxatin analogues.

    PubMed

    Inaoka, Y; Naruto, S

    1988-11-01

    Propioxatins A and B are inhibitors of enkephalinase B, which hydrolyzes enkephalin at the Gly-Gly bond. In order to clarify the structure-activity relationships of propioxatin, several compounds were synthesized and their inhibitory activity for not only enkephalinase B but also enkephalinase A was examined. The hydroxamic acid group in propioxatin was primarily essential for coordinating the metal ion in the active site of the enzyme. Among devalyl propioxatin A derivatives, the proline-containing compounds inhibited enkephalinase B and others inhibited both enzymes. An alteration of the character of the P3' amino acid valine in propioxatin A, e.g. amidation of carboxylic acid or replacement of the side chain, caused a 2 to 400-fold decrease of the inhibitory activity for enkephalinase B or an appearance of enkephalinase A inhibition with Ki values in the micromolar range. Substitution of the proline by alanine also resulted in a 1,000-fold loss of inhibitory activity for enkephalinase B. Propioxatin A was the most potent and specific inhibitor of enkephalinase B among the synthesized compounds. These potent and specific inhibitory effects were caused by the P2' proline residue, the P3' valine side chain and its free carboxylic acid. Each of the S1', S2', and S3' subsites in an enkephalinase B active site has a large and hydrophobic pocket, but the arrangement might be unique. The results could explain why enkephalinase B does not hydrolyze longer peptides.

  18. Thrombin inhibitor design.

    PubMed

    Sanderson, P E; Naylor-Olsen, A M

    1998-08-01

    Recently, iv formulated direct thrombin inhibitors have been shown to be safe and efficacious alternatives to heparin. These results have fueled the hopes for an orally active compound. Such a compound could be a significant advance over warfarin if it had predictable pharmacokinetics and a duration of action sufficient for once or twice a day dosing. In order to develop an orally active compound which meets these criteria, the deficiencies of the prototype inhibitor efegatran have had to be addressed. First, using a combination of structure based design and empirical structure optimization, more selective compounds have been identified by modifying the P1 group or by incorporating different peptidomimetic P2/P3 scaffolds. Secondly, this optimization has resulted in the development of potent and selective non-covalent inhibitors, thus bypassing the liabilities of the serine trap. Thirdly, oral bioavailability has been achieved while maintaining selectivity and efficacy through the incorporation of progressively less basic P1 groups. The duration of action of these compounds remains to be optimized. Other advances in thrombin inhibitor design have included the development of uncharged P1 groups and the discovery of two non-peptide templates.

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

    PubMed Central

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

    2014-01-01

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

  20. Visualization of positive transcription elongation factor b (P-TEFb) activation in living cells.

    PubMed

    Fujinaga, Koh; Luo, Zeping; Schaufele, Fred; Peterlin, B Matija

    2015-01-16

    Regulation of transcription elongation by positive transcription elongation factor b (P-TEFb) plays a central role in determining the state of cell activation, proliferation, and differentiation. In cells, P-TEFb exists in active and inactive forms. Its release from the inactive 7SK small nuclear ribonucleoprotein complex is a critical step for P-TEFb to activate transcription elongation. However, no good method exists to analyze this P-TEFb equilibrium in living cells. Only inaccurate and labor-intensive cell-free biochemical assays are currently available. In this study, we present the first experimental system to monitor P-TEFb activation in living cells. We created a bimolecular fluorescence complementation assay to detect interactions between P-TEFb and its substrate, the C-terminal domain of RNA polymerase II. When cells were treated with suberoylanilide hydroxamic acid, which releases P-TEFb from the 7SK small nuclear ribonucleoprotein, they turned green. Other known P-TEFb-releasing agents, including histone deacetylase inhibitors, bromodomain and extraterminal bromodomain inhibitors, and protein kinase C agonists, also scored positive in this assay. Finally, we identified 5'-azacytidine as a new P-TEFb-releasing agent. This release of P-TEFb correlated directly with activation of human HIV and HEXIM1 transcription. Thus, our visualization of P-TEFb activation by fluorescent complementation assay could be used to find new P-TEFb-releasing agents, compare different classes of agents, and assess their efficacy singly and/or in combination.

  1. Creating zinc monkey wrenches in the treatment of epigenetic disorders.

    PubMed

    Kalin, Jay Hans; Butler, Kyle Vincent; Kozikowski, Alan Paul

    2009-06-01

    The approval of suberoylanilide hydroxamic acid by the FDA for the treatment of cutaneous T-cell lymphoma in October, 2006 sparked a dramatic increase in the development of inhibitors for the class of enzymes known as the histone deacetylases (HDACs). In recent years, a large number of combination therapies involving histone deacetylase inhibitors (HDACIs) have been developed for the treatment of a variety of malignancies and neurodegenerative disorders. Promising evidence has been reported for the treatment of pancreatic cancer, prostate cancer, and leukemia as well as a number of other previously difficult to treat cancers. Drug combination approaches have also shown promise for the treatment of mood disorders including bipolar disorder and depression. In addition to these drug combination approaches, HDACIs alone have demonstrated effectiveness in the treatment of Parkinson's disease, Alzheimer's disease, Rubinstein-Taybi syndrome, Rett syndrome, Friedreich's ataxia, Huntington's disease, multiple sclerosis, anxiety, and schizophrenia. Adverse inflammatory affects observed with traumatic brain injury and arthritis have also been alleviated by treatment with certain HDACIs. Based on the diverse utility and wide range of mechanistic actions observed with this class of drugs, the future development of better drug combination therapies and more selective HDACIs is warranted.

  2. N-(2-hydroxyphenyl)-2-propylpentanamide, a valproic acid aryl derivative designed in silico with improved anti-proliferative activity in HeLa, rhabdomyosarcoma and breast cancer cells.

    PubMed

    Prestegui-Martel, Berenice; Bermúdez-Lugo, Jorge Antonio; Chávez-Blanco, Alma; Dueñas-González, Alfonso; García-Sánchez, José Rubén; Pérez-González, Oscar Alberto; Padilla-Martínez, Itzia Irene; Fragoso-Vázquez, Manuel Jonathan; Mendieta-Wejebe, Jessica Elena; Correa-Basurto, Ana María; Méndez-Luna, David; Trujillo-Ferrara, José; Correa-Basurto, José

    2016-01-01

    Epigenetic alterations are associated with cancer and their targeting is a promising approach for treatment of this disease. Among current epigenetic drugs, histone deacetylase (HDAC) inhibitors induce changes in gene expression that can lead to cell death in tumors. Valproic acid (VPA) is a HDAC inhibitor that has antitumor activity at mM range. However, it is known that VPA is a hepatotoxic drug. Therefore, the aim of this study was to design a set of VPA derivatives adding the arylamine core of the suberoylanilide hydroxamic acid (SAHA) with different substituents at its carboxyl group. These derivatives were submitted to docking simulations to select the most promising compound. The compound 2 (N-(2-hydroxyphenyl)-2-propylpentanamide) was the best candidate to be synthesized and evaluated in vitro as an anti-cancer agent against HeLa, rhabdomyosarcoma and breast cancer cell lines. Compound 2 showed a better IC50 (μM range) than VPA (mM range) on these cancer cells. And also, 2 was particularly effective on triple negative breast cancer cells. In conclusion, 2 is an example of drugs designed in silico that show biological properties against human cancer difficult to treat as triple negative breast cancer.

  3. Inhibition of monomethylarsonous acid (MMA(III))-induced cell malignant transformation through restoring dysregulated histone acetylation.

    PubMed

    Ge, Yichen; Gong, Zhihong; Olson, James R; Xu, Peilin; Buck, Michael J; Ren, Xuefeng

    2013-10-04

    Inorganic arsenic (iAs) and its high toxic metabolite, monomethylarsonous acid (MMA(III)), are able to induce malignant transformation of human cells. Chronic exposure to these chemicals is associated with an increased risk of developing multiple cancers in human. However, the mechanisms contributing to iAs/MMA(III)-induced cell malignant transformation and carcinogenesis are not fully elucidated. We recently showed that iAs/MMA(III) exposure to human cells led to a decreased level of histone acetylation globally, which was associated with an increased sensitivity to arsenic cytotoxicity. In the current study, it demonstrated that prolonged exposure to low-level MMA(III) in human urothelial cells significantly increased the expression and activity of histone deacetylases (HDACs) with an associated reduction of histone acetylation levels both globally and lysine specifically. Administration of the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), at 4 weeks after the initial MMA(III) treatment inhibited the MMA(III)-mediated up-regulation of the expression and activities of HDACs, leading to increase histone acetylation and prevention of MMA(III)-induced malignant transformation. These new findings suggest that histone acetylation dysregulation may be a key mechanism in MMA(III)-induced malignant transformation and carcinogenesis, and that HDAC inhibitors could be targeted to prevent or treat iAs-related cancers.

  4. Comparative effects of histone deacetylase inhibitors on p53 target gene expression, cell cycle and apoptosis in MCF-7 breast cancer cells.

    PubMed

    Knutson, Andrew Kekapa'a; Welsh, Jennifer; Taylor, Travis; Roy, Somdutta; Wang, Wei-Lin Winnie; Tenniswood, Martin

    2012-03-01

    Histone deacetylase inhibitors are currently being evaluated for their therapeutic potential and have shown considerable promise as adjuvant therapies for a number of cancers. This study compared the effects of 2 hydroxamic acid based inhibitors, CG-1521 and SAHA, on gene expression, cell cycle and cell death in MCF-7 human breast cancer cells. Both compounds show a dose- and time-dependent effect on cell number (evaluated using crystal violet), however CG-1521 exerts its effects significantly earlier than SAHA, and CG-1521 induces apoptosis (assessed by Apo-BrdU staining and flow cytometry) more rapidly than SAHA. qPCR of cell cycle regulatory and apoptotic genes shows that CG-1521 and SAHA modulate similar cohorts of p53-responsive genes, however, the levels of induction and the timing of the induction differs significantly between the 2 inhibitors. In particular SAHA downregulates cell cycle-associated genes that modulate the G1/S transition (including cyclin D1 and cdc25a) and the G2/M transition [cyclin B1, Plk1, Stk6 (serine-threonine kinase 6, Aurora kinase A) and Kntc2] more significantly than CG-1521. In contrast, CG-1521 significantly induces the expression of several p53 target genes associated with apoptosis including Bnip3/Bnip3L, p21/p21B and Gdf15. The differential levels of gene induction provide molecular evidence of both cell cycle arrest and apoptosis, and suggest a molecular mechanism that explains the difference in the biological effects of the 2 histone deacetylase inhibitors.

  5. Acyclic peptide inhibitors of amylases.

    PubMed

    Pohl, Nicola

    2005-12-01

    In this issue of Chemistry and Biology, a library screening approach reveals a linear octapeptide inhibitor of alpha-amylases reached by de novo design . The selected molecule shares characteristics with naturally occurring protein inhibitors -- a result that suggests general rules for the design of peptide-based amylase inhibitors may be achievable.

  6. [SGLT2 inhibitor].

    PubMed

    Kubota, Naoto; Kadowaki, Takashi

    2015-12-01

    SGLT2 is a glucose transporter which plays an important role for reabsorption of urinary glucose depending on the sodium concentration gradient. SGLT2 is mainly present in apical site of S1 segment of renal proximal tubule and accounts for approximately 90% of total urinary glucose reabsorption. SLC5a2, which codes SGLT2, is also known as the causative gene of familial renal glucosuria. SGLT2 inhibitors are attracting attention as newly developed oral anti-diabetic agents which improve glucose intolerance and also have an anti-obese effect by promoting urinary glucose excretion (UGE), which is a different pharmacological effect from other conventional anti-diabetic agents. In this review, we will discuss the effect of SGLT2 inhibitor on the regulation of glucose and lipid metabolism in type 2 diabetes.

  7. Protease inhibitor studies enrolling.

    PubMed

    1995-01-01

    The protease enzyme is essential for HIV to make copies of itself. So far, research has failed to find a protease inhibitor that works against HIV. It is believed that, regardless of what type of protease inhibitor someone takes, it will need to be supplemented with other anti-HIV drugs. Three protease inhibitors have thus far been found to be safe, although long-term effects are unknown. These drugs are saquinavir, ABT-538, and L-735,524 produced by Hoffman-LaRoche, Abbott, and Merck respectively. Clinical trials of saquinavir are promising but it has not been shown to be the knock-out drug needed. ABT-538 has high bioavailability, but studies are showing it can cause liver and eye damage. L-735,524 studies are showing that resistance develops quite quickly. Future studies at higher doses are expected. To obtain information on protease studies currently looking for participants, contact The Network. Information on other approved, alternative, and experimental drugs is also available.

  8. Development of scale inhibitors

    SciTech Connect

    Gill, J.S.

    1996-12-01

    During the last fifty years, scale inhibition has gone from an art to a science. Scale inhibition has changed from simple pH adjustment to the use of optimized dose of designer polymers from multiple monomers. The water-treatment industry faces many challenges due to the need to conserve water, availability of only low quality water, increasing environmental regulations of the water discharge, and concern for human safety when using acid. Natural materials such as starch, lignin, tannin, etc., have been replaced with hydrolytically stable organic phosphates and synthetic polymers. Most progress in scale inhibition has come from the use of synergistic mixtures and copolymerizing different functionalities to achieve specific goals. Development of scale inhibitors requires an understanding of the mechanism of crystal growth and its inhibition. This paper discusses the historic perspective of scale inhibition and the development of new inhibitors based on the understanding of the mechanism of crystal growth and the use of powerful tools like molecular modeling to visualize crystal-inhibitor interactions.

  9. Cox-2 inhibitors.

    PubMed

    Brown, E

    1999-01-01

    Increasing pharmacy costs are among the fastest growing segments of the health care budget. Health plans are focusing on appropriately managing pharmaceutical costs, both from a long-term global perspective and a short-term approach emphasizing newly marketed products. Over the next six months, cox-2 inhibitors are expected to be approved by the FDA. This new class of drugs, investigated as a safer alternative to non-steroidal anti-inflammatory drugs (NSAIDs), is among the most highly anticipated medications to hit the marketplace. How health plans react to the launch of cox-2 inhibitors may serve as an example for future pharmacy management efforts. A proactive policy regarding the use of cox-2 inhibitors may be challenging, but should include: Reviewing clinical information; evaluating the cost of the new drug; and identifying appropriate patient selection criteria. The available management strategies include precertification, a tiered co-payment system, restricting prescriptions to a provider specialty, retrospective physician profiling, and physician education.

  10. Structure of the catalytic domain of the Tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor

    PubMed Central

    Guevara, Tibisay; Ksiazek, Miroslaw; Skottrup, Peter Durand; Cerdà-Costa, Núria; Trillo-Muyo, Sergio; de Diego, Iñaki; Riise, Erik; Potempa, Jan; Gomis-Rüth, F. Xavier

    2013-01-01

    Karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen Tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. The very close structural and sequence-based similarity of its catalytic domain (Kly18) to matrix metallo­proteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. Previous studies by phage display identified peptides with the consensus sequence XWFPXXXGGG (single-letter amino-acid codes; X represents any residue) as karilysin inhibitors with low-micromolar binding affinities. Subsequent refinement revealed that inhibition comparable to that of longer peptides could be achieved using the tetrapeptide SWFP. To analyze its binding, the high-resolution crystal structure of the complex between Kly18 and SWFP was determined and it was found that the peptide binds to the primed side of the active-site cleft in a substrate-like manner. The catalytic zinc ion is clamped by the α-amino group and the carbonyl O atom of the serine, thus distantly mimicking the general manner of binding of hydroxamate inhibitors to metallopeptidases and contributing, together with three zinc-binding histidines from the protein scaffold, to an octahedral-minus-one metal-coordination sphere. The tryptophan side chain penetrates the deep partially water-filled specificity pocket of Kly18. Together with previous serendipitous product complexes of Kly18, the present results provide the structural determinants of inhibition of karilysin and open the field for the design of novel inhibitory strategies aimed at the treatment of human periodontal disease based on a peptidic hit molecule. PMID:23695557

  11. Structure of the catalytic domain of the Tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor.

    PubMed

    Guevara, Tibisay; Ksiazek, Miroslaw; Skottrup, Peter Durand; Cerdà-Costa, Núria; Trillo-Muyo, Sergio; de Diego, Iñaki; Riise, Erik; Potempa, Jan; Gomis-Rüth, F Xavier

    2013-05-01

    Karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen Tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. The very close structural and sequence-based similarity of its catalytic domain (Kly18) to matrix metalloproteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. Previous studies by phage display identified peptides with the consensus sequence XWFPXXXGGG (single-letter amino-acid codes; X represents any residue) as karilysin inhibitors with low-micromolar binding affinities. Subsequent refinement revealed that inhibition comparable to that of longer peptides could be achieved using the tetrapeptide SWFP. To analyze its binding, the high-resolution crystal structure of the complex between Kly18 and SWFP was determined and it was found that the peptide binds to the primed side of the active-site cleft in a substrate-like manner. The catalytic zinc ion is clamped by the α-amino group and the carbonyl O atom of the serine, thus distantly mimicking the general manner of binding of hydroxamate inhibitors to metallopeptidases and contributing, together with three zinc-binding histidines from the protein scaffold, to an octahedral-minus-one metal-coordination sphere. The tryptophan side chain penetrates the deep partially water-filled specificity pocket of Kly18. Together with previous serendipitous product complexes of Kly18, the present results provide the structural determinants of inhibition of karilysin and open the field for the design of novel inhibitory strategies aimed at the treatment of human periodontal disease based on a peptidic hit molecule.

  12. Synergistic Inhibition of Hepatocellular Carcinoma Growth by Cotargeting Chromatin Modifying Enzymes and Poly (ADP-ribose) Polymerases

    PubMed Central

    Zhang, Jun-Xiang; Li, Da-Qiang; He, Aiwu Ruth; Motwani, Mona; Vasiliou, Vasilis; Eswaran, Jeyanthy; Mishra, Lopa; Kumar, Rakesh

    2012-01-01

    Hepatocellular carcinoma (HCC) is a particularly lethal form of cancer, yet effective therapeutic options for advanced HCC are limited. As poly(ADP-ribose) polymerases (PARPs) and histone deacetylases (HDACs) are emerging to be among the most promising targets in cancer therapy, and sensitivity to PARP inhibition depends on homologous recombination (HR) deficiency and inhibition of HDAC activity blocks the HR pathway, we tested the hypothesis that co-targeting both enzymatic activities could synergistically inhibit HCC growth and defined the molecular determinants of sensitivity to both enzyme inhibitors. We discovered that HCC cells have differential sensitivity to HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and PARP inhibitor Olaparib, and identified one pair of cell lines, termed SNU-398 and SNU-449, with sensitive versus resistant phenotype to both enzyme inhibitors, respectively. Co-administration of SAHA and Olaparib synergistically inhibited the growth of SNU-398 but not SNU-449 cells, which was associated with increased apoptosis and accumulated unrepaired DNA damage. Multiple lines of evidence demonstrate that the hepatic fibrosis/hepatic stellate cell activation may be an important genetic determinant of cellular sensitivity to both enzymatic inhibitors, and coordinate activation or inactivation of the aryl hydrocarbon receptor (AhR) and cAMP-mediated signaling pathways are involved in cell response to SAHA and Olaparib treatment. Conclusion These findings suggest that combination therapy with both enzyme inhibitors may be a strategy for therapy of sensitive HCC cells, and identification of these novel molecular determinants may eventually guide the optimal use of PARP and HDAC inhibitors in the clinic. PMID:22223166

  13. Dual inhibition of histone deacetylases and phosphoinositide 3-kinases: effects on Burkitt lymphoma cell growth and migration.

    PubMed

    Ferreira, Ana Carolina dos Santos; de-Freitas-Junior, Julio Cesar Madureira; Morgado-Díaz, Jose Andres; Ridley, Anne J; Klumb, Claudete Esteves

    2016-04-01

    Burkitt lymphoma is a highly aggressive non-Hodgkin lymphoma that is characterized by MYC deregulation. Recently, the PI3K pathway has emerged as a cooperative prosurvival mechanism in Burkitt lymphoma. Despite the highly successful results of treatment that use high-dose chemotherapy regimens in pediatric Burkitt lymphoma patients, the survival rate of pediatric patients with progressive or recurrent disease is low. PI3Ks are also known to regulate cell migration, and abnormal cell migration may contribute to cancer progression and dissemination in Burkitt lymphoma. Little is known about Burkitt lymphoma cell migration, but the cooperation between MYC and PI3K in Burkitt lymphoma pathogenesis suggests that a drug combination could be used to target the different steps involved in Burkitt lymphoma cell dissemination and disease progression. The aim of this study was to investigate the effects of the histone deacetylase inhibitor suberoylanilide hydroxamic acid combined with the PI3K inhibitor LY294002 on Burkitt lymphoma cell growth and migration. The combination enhanced the cell growth inhibition and cell-cycle arrest induced by the PI3K inhibitor or histone deacetylase inhibitor individually. Moreover, histone deacetylase inhibitor/PI3K inhibitor cotreatment suppressed Burkitt lymphoma cell migration and decreased cell polarization, Akt and ERK1/2 phosphorylation, and leads to RhoB induction. In summary, the histone deacetylase inhibitor/PI3Ki combination inhibits cell proliferation and migration via alterations in PI3K signaling and histone deacetylase activity, which is involved in the acetylation of α-tubulin and the regulation of RhoB expression.

  14. [Tyrosine kinase inhibitors].

    PubMed

    Robert, Jacques

    2011-11-01

    Membrane receptors with tyrosine kinase activity and cytoplasmic tyrosine kinases have emerged as important potential targets in oncology. Starting from basic structures such as anilino-quinazoline, numerous compounds have been synthesised, with the help of tyrosine kinase crystallography, which has allowed to optimise protein-ligand interactions. The catalytic domains of all kinases present similar three-dimensional structures, which explains that it may be difficult to identify molecules having a high specificity for a given tyrosine kinase. Some tyrosine kinase inhibitors are relatively specific for epidermal growth factor receptor (EGFR) such as géfitinib and erlotinib; other are mainly active against platelet-derived growth factor receptor (PDGFR) and the receptor KIT, such as imatinib or nilotinib, and other against vascular endothelial growth factor (VEGF) receptors involved in angiogenesis, such as sunitinib and sorafenib. The oral formulation of tyrosine kinase inhibitors is well accepted by the patients but may generate sometimes compliance problems requiring pharmacokinetic monitoring. This chemical family is in full expansion and several dozens of compounds have entered clinical trials.

  15. Structural insights of SmKDAC8 inhibitors: Targeting Schistosoma epigenetics through a combined structure-based 3D QSAR, in vitro and synthesis strategy.

    PubMed

    Ballante, Flavio; Reddy, D Rajasekhar; Zhou, Nancy J; Marshall, Garland R

    2017-04-01

    A predictive structure-based 3D QSAR (COMBINEr 2.0) model of the Schistosoma mansoni lysine deacetylase 8 enzyme (SmKDAC8) was developed, validated and used to perform virtual screening (VS) of the NCI Diversity Set V database (1593 compounds). Three external datasets (with congeneric structures to those experimentally resolved in complexes by X-ray and previously reported as SmKDAC8 inhibitors) were employed to compose and validate the most predictive model. Two series characterized by 104 benzodiazepine derivatives (BZDs) and 60 simplified largazole analogs (SLAs), recently reported by our group as human KDAC inhibitors, were tested for their inhibition potency against SmKDAC8 to probe the predictive capability of the quantitative models against compounds with diverse structures. The SmKDAC8 biochemical results confirmed: (1) the benzodiazepine moiety as a valuable scaffold to further investigate when pursuing SmKDAC8 inhibition; (2) the predictive capability of the COMBINEr 2.0 model towards non-congeneric series of compounds, highlighting the most influencing ligand-protein interactions and refining the structure-activity relationships. From the VS investigations, the first 40 top-ranked compounds were obtained and biologically tested for their inhibition potency against SmKDAC8 and hKDACs 1, 3, 6 and 8. Among them, a non-hydroxamic acid benzothiadiazine dioxide derivative (code NSC163639), showed interesting activity and selectivity against SmKDAC8. To further elucidate the structure-activity relationships of NSC163639, two analogs (herein reported as compounds 3 and 4) were synthesized and biologically evaluated. Results suggest the benzothiadiazine dioxide moiety as a promising scaffold to be used in a next step to derive selective SmKDAC8 inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. ADAM10 new selective inhibitors reduce NKG2D ligand release sensitizing Hodgkin lymphoma cells to NKG2D-mediated killing.

    PubMed

    Zocchi, Maria Raffaella; Camodeca, Caterina; Nuti, Elisa; Rossello, Armando; Venè, Roberta; Tosetti, Francesca; Dapino, Irene; Costa, Delfina; Musso, Alessandra; Poggi, Alessandro

    2016-05-01

    Hodgkin lymphoma (HL) resistant to conventional therapies is increasing, making of interest the search for new schemes of treatment. Members of the "A Disintegrin And Metalloproteases" (ADAMs) family, mainly ADAM10 or ADAM17, have been proposed as therapeutic targets in solid tumors and some ADAMs inhibitors have been shown to exert antitumor effects. We have previously described an overexpression of ADAM10 in HL, together with increased release of NKG2D ligands (NKG2D-L) and reduced activation of effector T lymphocytes with anti-lymphoma capacity. Aim of the present work was to verify whether inhibition of ADAM10 in HL cells could restore the triggering of NKG2D-dependent anti-lymphoma T cell response. As no selective ADAM10 blockers have been reported so far, we synthesized the two hydroxamate compounds LT4 and MN8 with selectivity for ADAM10 over metalloproteases (MMPs), LT4 showing higher specificity for ADAM10 over ADAM17. We show that (i) HL lymph nodes (LN) and cultured HL cells express high levels of the mature active membrane form of ADAM10; (ii) ADAM10 is the major sheddase for the NKG2D-L in HL cells; (iii) the new LT4 and MN8 compounds strongly reduce the shedding of NKG2D-L by HL cell lines and enhance the binding of NKG2D receptor; (iv) of note, these new ADAM10 inhibitors increase the sensitivity of HL cell lines to NKG2D-dependent cell killing exerted by natural killer and γδ T cells. Overall, the biologic activity of LT4 and MN8 appears to be more potent than that of the commercial inhibitor GI254023X.

  17. Safety and efficacy of abexinostat, a pan-histone deacetylase inhibitor, in non-Hodgkin lymphoma and chronic lymphocytic leukemia: results of a phase II study.

    PubMed

    Ribrag, Vincent; Kim, Won Seog; Bouabdallah, Reda; Lim, Soon Thye; Coiffier, Bertrand; Illes, Arpad; Lemieux, Bernard; Dyer, Martin J S; Offner, Fritz; Felloussi, Zakia; Kloos, Ioana; Luan, Ying; Vezan, Remus; Graef, Thorsten; Morschhauser, Franck

    2017-05-01

    Histone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in B-cell lymphomas. Abexinostat is an orally available hydroxamate-containing histone deacetylase inhibitor that differs from approved inhibitors; its unique pharmacokinetic profile and oral dosing schedule, twice daily four hours apart, allows for continuous exposure at concentrations required to efficiently kill tumor cells. In this phase II study, patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia received oral abexinostat at 80 mg BID for 14 days of a 21-day cycle and continued until progressive disease or unacceptable toxicity. A total of 100 patients with B-cell malignancies and T-cell lymphomas were enrolled between October 2011 and July 2014. All patients received at least one dose of study drug. Primary reasons for discontinuation included progressive disease (56%) and adverse events (25%). Grade 3 or over adverse events and any serious adverse events were reported in 88% and 73% of patients, respectively. The most frequently reported grade 3 or over treatment-emergent related adverse events were thrombocytopenia (80%), neutropenia (27%), and anemia (12%). Among the 87 patients evaluable for efficacy, overall response rate was 28% (complete response 5%), with highest responses observed in patients with follicular lymphoma (overall response rate 56%), T-cell lymphoma (overall response rate 40%), and diffuse large B-cell lymphoma (overall response rate 31%). Further investigation of the safety and efficacy of abexinostat in follicular lymphoma, T-cell lymphoma, and diffuse large B-cell lymphoma implementing a less dose-intense week-on-week-off schedule is warranted. (Trial registered at: EudraCT-2009-013691-47). Copyright© Ferrata Storti Foundation.

  18. 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

  19. ADAM10 new selective inhibitors reduce NKG2D ligand release sensitizing Hodgkin lymphoma cells to NKG2D-mediated killing

    PubMed Central

    Zocchi, Maria Raffaella; Camodeca, Caterina; Nuti, Elisa; Rossello, Armando; Venè, Roberta; Tosetti, Francesca; Dapino, Irene; Costa, Delfina; Musso, Alessandra; Poggi, Alessandro

    2016-01-01

    ABSTRACT Hodgkin lymphoma (HL) resistant to conventional therapies is increasing, making of interest the search for new schemes of treatment. Members of the “A Disintegrin And Metalloproteases” (ADAMs) family, mainly ADAM10 or ADAM17, have been proposed as therapeutic targets in solid tumors and some ADAMs inhibitors have been shown to exert antitumor effects. We have previously described an overexpression of ADAM10 in HL, together with increased release of NKG2D ligands (NKG2D-L) and reduced activation of effector T lymphocytes with anti-lymphoma capacity. Aim of the present work was to verify whether inhibition of ADAM10 in HL cells could restore the triggering of NKG2D-dependent anti-lymphoma T cell response. As no selective ADAM10 blockers have been reported so far, we synthesized the two hydroxamate compounds LT4 and MN8 with selectivity for ADAM10 over metalloproteases (MMPs), LT4 showing higher specificity for ADAM10 over ADAM17. We show that (i) HL lymph nodes (LN) and cultured HL cells express high levels of the mature active membrane form of ADAM10; (ii) ADAM10 is the major sheddase for the NKG2D-L in HL cells; (iii) the new LT4 and MN8 compounds strongly reduce the shedding of NKG2D-L by HL cell lines and enhance the binding of NKG2D receptor; (iv) of note, these new ADAM10 inhibitors increase the sensitivity of HL cell lines to NKG2D-dependent cell killing exerted by natural killer and γδ T cells. Overall, the biologic activity of LT4 and MN8 appears to be more potent than that of the commercial inhibitor GI254023X. PMID:27467923

  20. Targeting the invasive phenotype of cisplatin-resistant non-small cell lung cancer cells by a novel histone deacetylase inhibitor.

    PubMed

    Zuco, Valentina; Cassinelli, Giuliana; Cossa, Giacomo; Gatti, Laura; Favini, Enrica; Tortoreto, Monica; Cominetti, Denis; Scanziani, Eugenio; Castiglioni, Vittoria; Cincinelli, Raffaella; Giannini, Giuseppe; Zunino, Franco; Zaffaroni, Nadia; Lanzi, Cinzia; Perego, Paola

    2015-03-15

    Non-Small Cell Lung Cancer (NSCLC) remains an aggressive and fatal disease with low responsiveness to chemotherapy, frequent drug resistance development and metastatic behavior. Platinum-based therapy is the standard of care for NSCLC with limited benefits. Since epigenetic alterations have been implicated in the aggressive behavior of lung cancer, the purpose of the present study was to examine the capability of the pan-histone deacetylase inhibitor SAHA and of ST3595, a novel hydroxamate-based compound, to interfere with the proliferative and invasive potential of NSCLC cells. We used two NSCLC cell lines (H460 and A549) and the cisplatin-resistant variants (H460/Pt and A549/Pt), to mimic a frequent clinical condition. The resistant models exhibited increased invasive properties as compared to parental cells, features associated with a wide modulation of the level of angiogenesis- and invasion-related factors in the cell conditioned media. The levels of urokinase-type plasminogen activator, IL-8, and macrophage migration inhibitory factor were increased in the conditioned media from both H460/Pt and A549/Pt cells. SAHA and ST3595 induced a strong inhibition of cell invasive properties, which was more marked after ST3595 exposure. Both HDAC inhibitors up-regulated the metastasis suppressor KiSS1 at the mRNA level. Forced expression of KiSS1 significantly decreased the invasive capability of drug-resistant cells. ST3595 displayed an anti-metastatic effect in tumors associated with decreased of phosphorylation of Src. Our data indicate that HDAC inhibitors are effective in NSCLC cell systems. The ability of ST3595 to counteract the invasive potential of resistant cells through mechanisms involving KiSS1 is an interesting novel finding.

  1. Synthesis of Lysine Methyltransferase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ye, Tao; Hui, Chunngai

    2015-07-01

    Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  2. ABCD1 deletion-induced mitochondrial dysfunction is corrected by SAHA: implication for adrenoleukodystrophy

    PubMed Central

    Baarine, Mauhamad; Beeson, Craig; Singh, Avtar; Singh, Inderjit

    2015-01-01

    X-linked Adrenoleukodystrophy (X-ALD), an inherited peroxisomal metabolic neurodegenerative disorder, is caused by mutations/deletions in the ABCD1 gene encoding peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). Metabolic dysfunction in X-ALD is characterized by the accumulation of very long chain fatty acids (VLCFAs; ≥ C22:0) in the tissues and plasma of patients. Here, we investigated the mitochondrial status following deletion of ABCD1 in B12 oligodendrocytes and U87 astrocytes. This study provides evidence that silencing of peroxisomal protein ABCD1 produces structural and functional perturbations in mitochondria. Activities of electron transport chain-related enzymes and of citric acid cycle (TCA cycle) were reduced; mitochondrial redox status was dysregulated and the mitochondrial membrane potential was disrupted following ABCD1 silencing. A greater reduction of ATP levels and citrate synthase activities was observed in oligodendrocytes as compared to astrocytes. Further, most of the mitochondrial perturbations induced by ABCD1 silencing were corrected by treating cells with SAHA (suberoylanilide hydroxamic acid), an HDAC inhibitor. These observations indicate a novel relationship between peroxisomes and mitochondria in cellular homeostasis and the importance of intact peroxisomes in relation to mitochondrial integrity and function in the cell types that participate in the pathobiology of X-ALD. These observations suggest SAHA as a potential therapy for X-ALD. PMID:25393703

  3. Radiosensitization by SAHA in Experimental Colorectal Carcinoma Models-In Vivo Effects and Relevance of Histone Acetylation Status

    SciTech Connect

    Folkvord, Sigurd; Ree, Anne Hansen; Furre, Torbjorn; Halvorsen, Thomas; Flatmark, Kjersti

    2009-06-01

    Purpose: Histone deacetylase inhibitors are being evaluated as antitumor agents in ongoing clinical trials, and promising preclinical results, combined with favorable toxicity profiles, have rendered the drugs as interesting candidates for combination with other treatment modalities, such as radiotherapy. The aim of the present study was to evaluate the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) and the possible requirement of histone hyperacetylation at radiation exposure. Methods and materials: Radiosensitization by SAHA was assessed in a colorectal carcinoma cell line and in two colorectal xenograft models by analysis of clonogenic survival and tumor growth delay, respectively. Histone acetylation status at radiation exposure was evaluated by Western blot. Results: In vitro, radiosensitization was demonstrated when cells were preincubated with SAHA, and, in the xenografts, tumor growth was delayed when the mice were treated with fractionated radiation combined with daily SAHA injections compared with radiation alone. Surprisingly, the SAHA-dependent growth delay was still present when radiation was delivered at restored baseline acetylation levels compared with maximal histone hyperacetylation. Conclusion: SAHA was an effective radiosensitizer in experimental colorectal carcinoma models, suggesting that histone deacetylase inhibition might constitute a valuable supplement to current multimodal treatment strategies in rectal cancer. The presence of histone hyperacetylation at radiation was not required to obtain an increased radiation response, questioning the validity of using histone hyperacetylation as a molecular marker for radiosensitivity.

  4. D1/D5 receptors and histone deacetylation mediate the Gateway Effect of LTP in hippocampal dentate gyrus.

    PubMed

    Huang, Yan-You; Levine, Amir; Kandel, Denise B; Yin, Deqi; Colnaghi, Luca; Drisaldi, Bettina; Kandel, Eric R

    2014-02-18

    The dentate gyrus (DG) of the hippocampus is critical for spatial memory and is also thought to be involved in the formation of drug-related associative memory. Here, we attempt to test an aspect of the Gateway Hypothesis, by studying the effect of consecutive exposure to nicotine and cocaine on long-term synaptic potentiation (LTP) in the DG. We find that a single injection of cocaine does not alter LTP. However, pretreatment with nicotine followed by a single injection of cocaine causes a substantial enhancement of LTP. This priming effect of nicotine is unidirectional: There is no enhancement of LTP if cocaine is administrated prior to nicotine. The facilitation induced by nicotine and cocaine can be blocked by oral administration of the dopamine D1/D5 receptor antagonist (SKF 83566) and enhanced by the D1/D5 agonist (SKF 38393). Application of the histone deacetylation inhibitor suberoylanilide hydroxamic acid (SAHA) simulates the priming effect of nicotine on cocaine. By contrast, the priming effect of nicotine on cocaine is blocked in genetically modified mice that are haploinsufficient for the CREB-binding protein (CBP) and possess only one functional CBP allele and therefore exhibit a reduction in histone acetylation. These results demonstrate that the DG of the hippocampus is an important brain region contributing to the priming effect of nicotine on cocaine. Moreover, both activation of dopamine-D1 receptor/PKA signaling pathway and histone deacetylation/CBP mediated transcription are required for the nicotine priming effect in the DG.

  5. Quantification of SAHA-Dependent Changes in Histone Modifications Using Data-Independent Acquisition Mass Spectrometry

    PubMed Central

    Krautkramer, Kimberly A.; Reiter, Lukas; Denu, John M.; Dowell, James A.

    2015-01-01

    Histone post-translational modifications (PTMs) are important regulators of chromatin structure and gene expression. Quantitative analysis of histone PTMs by mass spectrometry remains extremely challenging due to the complex and combinatorial nature of histone PTMs. The most commonly used mass spectrometry-based method for high-throughput histone PTM analysis is data-dependent acquisition (DDA). However, stochastic precursor selection and dependence on MS1 ions for quantification impede comprehensive interrogation of histone PTM states using DDA methods. To overcome these limitations, we utilized a data-independent acquisition (DIA) workflow that provides superior run-to-run consistency and post-acquisition flexibility in comparison to DDA methods. In addition, we developed a novel DIA-based methodology to quantify isobaric, co-eluting histone peptides that lack unique MS2 transitions. Our method enabled deconvolution and quantification of histone PTMs that are otherwise refractory to quantitation, including the heavily acetylated tail of histone H4. Using this workflow, we investigated the effects of the histone deacetylase inhibitor SAHA (suberoylanilide hydroxamic acid) on the global histone PTM state of human breast cancer MCF7 cells. A total of 62 unique histone PTMs were quantified, revealing novel SAHA-induced changes in acetylation and methylation of histones H3 and H4. PMID:26120868

  6. Cell cycle regulatory effects of retinoic Acid and forskolin are mediated by the cyclin C gene.

    PubMed

    Makkonen, Katri M; Malinen, Marjo; Ropponen, Antti; Väisänen, Sami; Carlberg, Carsten

    2009-10-23

    As a partner of cyclin-dependent kinase (CDK) 3, Cyclin C controls cellular proliferation and, together with CDK8, represses gene transcription. In this study, we showed that the highly expressed Cyclin C gene is a direct target of the nuclear hormone all-trans retinoic acid (RA) in HEK293 human embryonal kidney cells. The RA receptor (RAR) gamma associates with a Cyclin C promoter region containing two RAR binding sites. The Cyclin C gene also directly responds to the cAMP activator Forskolin via the transcription factor CREB1 (cAMP response element-binding protein 1), for which we identified four binding sites within the first 2250 bp of its promoter. RARgamma and CREB1 show functional convergence via the corepressor NCoR1, which controls in particular the Forskolin response of Cyclin C. The histone deacetylases 1, 5, 6, 7 and 11 are involved in the basal expression of Cyclin C, but in HEK293 and MCF-7 human breast carcinoma cells the antiproliferative effects of the histone deacetylase inhibitor SAHA (suberoylanilide hydroxamic acid) are not mediated by Cyclin C. However, cell cycle progressing effects of all-trans RA and Forskolin are dependent on Cyclin C expression levels. This suggests that the primary regulation of Cyclin C by all-trans RA and Forskolin mediates some of the cell cycle control actions of these compounds.

  7. Enhancement of Radiation Response in Osteosarcoma and Rhabomyosarcoma Cell Lines by Histone Deacetylase Inhibition

    SciTech Connect

    Blattmann, Claudia; Oertel, Susanne; Ehemann, Volker

    2010-09-01

    Purpose: Histone deacetylase inhibitors (HDACIs) can enhance the sensitivity of cells to photon radiation treatment (XRT) by altering numerous molecular pathways. We investigated the effect of pan-HDACIs such as suberoylanilide hydroxamic acid (SAHA) on radiation response in two osteosarcoma (OS) and two rhabdomyosarcoma (RMS) cell lines. Methods and Materials: Clonogenic survival, cell cycle analysis, and apoptosis were examined in OS (KHOS-24OS, SAOS2) and RMS (A-204, RD) cell lines treated with HDACI and HDACI plus XRT, respectively. Protein expression was investigated via immunoblot analysis, and cell cycle analysis and measurement of apoptosis were performed using flow cytometry. Results: SAHA induced an inhibition of cell proliferation and clonogenic survival in OS and RMS cell lines and led to a significant radiosensitization of all tumor cell lines. Other HDACI such as M344 and valproate showed similar effects as investigated in one OS cell line. Furthermore, SAHA significantly increased radiation-induced apoptosis in the OS cell lines, whereas in the RMS cell lines radiation-induced apoptosis was insignificant with and without SAHA. In all investigated sarcoma cell lines, SAHA attenuated radiation-induced DNA repair protein expression (Rad51, Ku80). Conclusion: Our results show that HDACIs enhance radiation action in OS and RMS cell lines. Inhibition of DNA repair, as well as increased apoptosis induction after exposure to HDACIs, can be mechanisms of radiosensitization by HDACIs.

  8. Sensitization of RPE cells by alphaB-crystallin siRNA to SAHA-induced stage 1 apoptosis through abolishing the association of alphaB-crystallin with HDAC1 in SC35 speckles.

    PubMed

    Noh, Seung Jin; Jeong, Woo Jin; Rho, Jee Hyun; Shin, Dong Min; Ahn, Hee Bae; Park, Woo Chan; Rho, Sae Heun; Soung, Young Hwa; Kim, Tae Hyun; Park, Bong Soo; Yoo, Young Hyun

    2008-11-01

    To better understand the mechanism underlying the anti-apoptotic activity of alphaB-crystallin in RPE cells. Cells of the human retinal pigment epithelial line ARPE-19 were treated with a histone deacetylase inhibitor (HDACI), suberoylanilide hydroxamic acid (SAHA), with or without alphaB-crystallin siRNA. To examine the mechanism underlying the cell death induced in ARPE-19 cells, nuclear staining, flow cytometry, DNA electrophoresis, pulse field gel electrophoresis, Western blot analysis, confocal microscopy, and coimmunoprecipitation assay were undertaken. The present study demonstrated that an HDACI, SAHA, at the usual doses or the silencing of alphaB-crystallin by siRNA alone did not effectively induce apoptosis in ARPE-19 cells. Silencing of alphaB-crystallin likely abolishes the anti-apoptotic activity of alphaB-crystallin. The data indicated that silencing of alphaB-crystallin sensitizes ARPE19 cells to SAHA-induced apoptosis and leads them to stage 1 apoptosis. alphaB-Crystallin associates with HDAC1 on SC35 speckles, and silencing of alphaB-crystallin abolishes this association, resulting in the induction of apoptosis. The data indicated that the association between alphaB-crystallin and HDAC1 on SC35 speckles plays a pivotal role in anti-apoptotic activity. Knockout of alphaB-crystallin may be a promising new approach to enhance therapeutic potency for proliferative vitreoretinopathy without compromising efficacy.

  9. Sequencing of aromatase inhibitors

    PubMed Central

    Bertelli, G

    2005-01-01

    Since the development of the third-generation aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, these agents have been the subject of intensive research to determine their optimal use in advanced breast cancer. Not only have they replaced progestins in second-line therapy and challenged the role of tamoxifen in first-line, but there is also evidence for a lack of cross-resistance between the steroidal and nonsteroidal AIs, meaning that they may be used in sequence to obtain prolonged clinical benefit. Many questions remain, however, as to the best sequence of the two types of AIs and of the other available agents, including tamoxifen and fulvestrant, in different patient groups. PMID:16100523

  10. Sirtuin activators and inhibitors

    PubMed Central

    Villalba, José M.; Alcaín, Francisco J.

    2012-01-01

    Sirtuins 1-7 (SIRT1-7) belong to the third class of deacetylase enzymes, which are dependent on NAD+ for activity. Sirtuins activity is linked to gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection and healthy aging. Because sirtuins modulation could have beneficial effects on human diseases there is a growing interest in the discovery of small molecules modifying their activity. We review here those compounds known to activate or inhibit sirtuins, discussing the data that support the use of sirtuin-based therapies. Almost all sirtuin activators have been described only for SIRT1. Resveratrol is a natural compound which activates SIRT1, and may help in the treatment or prevention of obesity, and in preventing tumorigenesis and the aging-related decline in heart function and neuronal loss. Due to its poor bioavailability, reformulated versions of resveratrol with improved bioavailability have been developed (resVida, Longevinex®, SRT501). Molecules that are structurally unrelated to resveratrol (SRT1720, SRT2104, SRT2379, among others) have been also developed to stimulate sirtuin activities more potently than resveratrol. Sirtuin inhibitors with a wide range of core structures have been identified for SIRT1, SIRT2, SIRT3 and SIRT5 (splitomicin, sirtinol, AGK2, cambinol, suramin, tenovin, salermide, among others). SIRT1 inhibition has been proposed in the treatment of cancer, immunodeficiency virus infections, Fragile X mental retardation syndrome and for preventing or treating parasitic diseases, whereas SIRT2 inhibitors might be useful for the treatment of cancer and neurodegenerative diseases. PMID:22730114

  11. Biological abatement of cellulase inhibitors

    USDA-ARS?s Scientific Manuscript database

    Bio-abatement uses a fungus to metabolize and remove fermentation inhibitors. To determine whether bio-abatement could alleviate enzyme inhibitor effects observed in biomass liquors after pretreatment, corn stover at 10% (w/v) solids was pretreated with either dilute acid or liquid hot water. The ...

  12. Authentic HIV-1 integrase inhibitors

    PubMed Central

    Liao, Chenzhong; Marchand, Christophe; Burke, Terrence R; Pommier, Yves; Nicklaus, Marc C

    2010-01-01

    HIV-1 integrase (IN) is indispensable for HIV-1 replication and has become a validated target for developing anti-AIDS agents. In two decades of development of IN inhibition-based anti-HIV therapeutics, a significant number of compounds were identified as IN inhibitors, but only some of them showed antiviral activity. This article reviews a number of patented HIV-1 IN inhibitors, especially those that possess high selectivity for the strand transfer reaction. These compounds generally have a polar coplanar moiety, which is assumed to chelate two magnesium ions in the binding site. Resistance to those compounds, when given to patients, can develop as a result of IN mutations. We refer to those compounds as authentic IN inhibitors. Continued drug development has so far delivered one authentic IN inhibitor to the market (raltegravir in 2007). Current and future attention will be focused on the development of novel authentic IN inhibitors with the goal of overcoming viral resistance. PMID:21426159

  13. The 1.8-A crystal structure of a matrix metalloproteinase 8-barbiturate inhibitor complex reveals a previously unobserved mechanism for collagenase substrate recognition.

    PubMed

    Brandstetter, H; Grams, F; Glitz, D; Lang, A; Huber, R; Bode, W; Krell, H W; Engh, R A

    2001-05-18

    The individual zinc endoproteinases of the tissue degrading matrix metalloproteinase (MMP) family share a common catalytic architecture but are differentiated with respect to substrate specificity, localization, and activation. Variation in domain structure and more subtle structural differences control their characteristic specificity profiles for substrates from among four distinct classes (Nagase, H., and Woessner, J. F. J. (1999) J. Biol. Chem. 274, 21491-21494). Exploitation of these differences may be decisive for the design of anticancer or other drugs, which should be highly selective for their particular MMP targets. Based on the 1.8-A crystal structure of human neutrophil collagenase (MMP-8) in complex with an active site-directed inhibitor (RO200-1770), we identify and describe new structural determinants for substrate and inhibitor recognition in addition to the primary substrate recognition sites. RO200-1770 induces a major rearrangement at a position relevant to substrate recognition near the MMP-8 active site (Ala206-Asn218). In stromelysin (MMP-3), competing stabilizing interactions at the analogous segment hinder a similar rearrangement, consistent with kinetic profiling of several MMPs. Despite the apparent dissimilarity of the inhibitors, the central 2-hydroxypyrimidine-4,6-dione (barbiturate) ring of the inhibitor RO200-1770 mimics the interactions of the hydroxamate-derived inhibitor batimastat (Grams, F., Reinemer, P., Powers, J. C., Kleine, T., Pieper, M., Tschesche, H., Huber, R., and Bode, W. (1995) Eur. J. Biochem. 228, 830-841) for binding to MMP-8. The two additional phenyl and piperidyl ring substituents of the inhibitor bind into the S1' and S2' pockets of MMP-8, respectively. The crystal lattice contains a hydrogen bond between the O(gamma) group of Ser209 and N(delta)1 of His207 of a symmetry related molecule; this interaction suggests a model for recognition of hydroxyprolines present in physiological substrates. We also identify a

  14. Tryptase inhibitors: a patent review.

    PubMed

    Ni, Wei-Wei; Cao, Meng-Da; Huang, Wen; Meng, Ling; Wei, Ji-Fu

    2017-08-01

    Tryptase is one of the main serine-proteinases located in the secretory granules of mast cells, and is released through degranulation, which is involved in the pathogenesis of allergic inflammatory disease, cardiovascular diseases, lung fibrosis and tumor. Therefore, inhibitors targeting tryptase may represent a new direction for the treatment of allergic inflammatory disease and other diseases. Areas covered: In this article, we discussed the history and development of tryptase inhibitors and described a variety of tryptase inhibitors via their structures and biological importance in clinical studies and drug development for tryptase-related diseases. Expert opinion: Initial tryptase inhibitors based on indole structure as the hydrophobic substituent on a benzylamine-piperidine template have low specificity and poor bioavailability. Therefore, designing new and specific inhibitors targeting tryptase should be involved in future clinical studies. Modifications toward indoles with varying N-substitution, introducing an amide bond, and growing the chain length contribute to an increase in the specific selectivity and potency of tryptase inhibitors. Tryptase has become the research hotspot to explore many related diseases. Therefore, there has been growing appreciation for the potential importance of the tryptase inhibitors as a target for treating these diseases.

  15. Inhibitors of plant hormone transport.

    PubMed

    Klíma, Petr; Laňková, Martina; Zažímalová, Eva

    2016-11-01

    Here we present an overview of what is known about endogenous plant compounds that act as inhibitors of hormonal transport processes in plants, about their identity and mechanism of action. We have also summarized commonly and less commonly used compounds of non-plant origin and synthetic drugs that show at least partial 'specificity' to transport or transporters of particular phytohormones. Our main attention is focused on the inhibitors of auxin transport. The urgent need to understand precisely the molecular mechanism of action of these inhibitors is highlighted.

  16. Adamantanyl-Histone Deacetylase Inhibitor H6CAHA Exhibits Favorable Pharmacokinetics and Augments Prostate Cancer Radiation Sensitivity

    SciTech Connect

    Konsoula, Zacharoula; Cao Hong; Velena, Alfredo; Jung, Mira

    2011-04-01

    Purpose: To evaluate pharmacological properties of H6CAHA, an adamantyl-hydroxamate histone deacetylase inhibitor, and to investigate its effect on prostate cancer cells following exposure to {gamma}-radiation in vitro and in vivo. Methods and Materials: H6CAHA was assessed for in vitro solubility, lipophilicity and growth inhibition, and in vivo plasma pharmacokinetics. The effect of H6CAHA on radiation clonogenic survival and DNA damage repair was evaluated in human prostate cancer (PC3, DU145, LNCaP) and nonmalignant control epithelial (RWPE1 and 267B1) cell lines. The effect of this agent on the growth of prostate cancer xenografts was also assessed in mice. Results: H6CAHA demonstrated good solubility and permeability profiles and preferentially inhibited the growth of prostate cancer cells over nonmalignant cells. Plasma pharmacokinetics revealed that the area under the curve of H6CAHA was 8.08 {+-} 0.91 {mu}M x h, and its half-life was 11.17 {+-} 0.87 h. Radiation clonogenic assays revealed that H6CAHA decreased the survival of prostate cancer cells at the dose that exerted limited effect on normal cells. Concomitantly, delayed DNA damage repair following combination treatment was evident in cancer cells, indicated by the prolonged appearance of {gamma}H2AX and Rad51 foci and suppression of DNA damage repair genes (ATM, BRCA1, and BRCA2). Combined modality of H6CAHA (daily intraperitoneal injections for 10 days) with {gamma}-radiation (10 x 2 Gy) completely blocked the growth of PC3 tumor xenografts (p < 0.001) over 60 days. Conclusion: These results support the potential therapeutic value of H6CAHA in combination with radiation and support the rationale for further clinical investigation.

  17. 2-Alkylamino- and alkoxy-substituted 2-amino-1,3,4-oxadiazoles-O-Alkyl benzohydroxamate esters replacements retain the desired inhibition and selectivity against MEK (MAP ERK kinase)

    SciTech Connect

    Warmus, Joseph S; Flamme, Cathlin; Zhang, Lu Yan; Barrett, Stephen; Bridges, Alexander; Chen, Huifen; Gowan, Richard; Kaufman, Michael; Sebolt-Leopold, Judy; Leopold, Wilbur; Merriman, Ronald; Ohren, Jeffrey; Pavlovsky, Alexander; Przybranowski, Sally; Tecle, Haile; Valik, Heather; Whitehead, Christopher; Zhang, Erli

    2009-07-23

    This paper reports a second generation MEK inhibitor. The previously reported potent and efficacious MEK inhibitor, PD-184352 (CI-1040), contains an integral hydroxamate moiety. This compound suffered from less than ideal solubility and metabolic stability. An oxadiazole moiety behaves as a bioisostere for the hydroxamate group, leading to a more metabolically stable and efficacious MEK inhibitor.

  18. Cholinesterase inhibitors and beyond.

    PubMed

    Pepeu, Giancarlo; Giovannini, Maria Grazia

    2009-04-01

    Cholinesterase inhibitors (ChEIs) were introduced in the therapy of Alzheimer Disease (AD) in the nineteen nineties with great expectations. The hopes and large interest raised by these drugs are well demonstrated by 12,000 references listed by PubMed under 'ChEI' for 1995-2007. The list is reduced to 2500 if we confine ourselves to 'ChEIs and dementia'. Of them, about 500 were published in the last two years. Whereas an increase in brain acetylcholine and an improvement of cognitive deficits have been consistently demonstrated in animal models of AD, from aging rats to transgenic mice, the clinical effectiveness of ChEIs has been and is still a matter of contrasting opinions. These range from the negative conclusions of the AD2000 trial on donepezil, claiming that it is not cost effective, with benefits below a minimally relevant threshold, to the NICE appraisal of 2007 declaring that donepezil, rivastigmine, galantamine are efficacious for mild to moderate AD, irrespective of their different selectivity for acetyl- (AChE) and butyrylcholinesterase (BuChE). The possibility that ChEIs may exert their effects through mechanisms beyond cholinesterase inhibition has been envisaged. However, according to the information presented in this review, the "classical" ChEIs, donepezil, rivastigmine and galantamine, show no pharmacological actions beyond cholinesterase inhibition which may play an important role in their therapeutic efficacy. The diverging opinions on clinical efficacy do not discourage from developing new ChEIs, and particularly the so called multifunctional ChEIs. They represent the future of the cholinergic therapy for AD but other indications for these drugs may be considered, including vascular dementia, mild cognitive impairment, and the ethically sensitive improvement of memory and learning in healthy subjects.

  19. Selective Inhibitors of Protein Methyltransferases

    PubMed Central

    2015-01-01

    Mounting evidence suggests that protein methyltransferases (PMTs), which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and human diseases. In particular, PMTs have been recognized as major players in regulating gene expression and chromatin state. PMTs are divided into two categories: protein lysine methyltransferases (PKMTs) and protein arginine methyltransferases (PRMTs). There has been a steadily growing interest in these enzymes as potential therapeutic targets and therefore discovery of PMT inhibitors has also been pursued increasingly over the past decade. Here, we present a perspective on selective, small-molecule inhibitors of PMTs with an emphasis on their discovery, characterization, and applicability as chemical tools for deciphering the target PMTs’ physiological functions and involvement in human diseases. We highlight the current state of PMT inhibitors and discuss future directions and opportunities for PMT inhibitor discovery. PMID:25406853

  20. Synthesis of lysine methyltransferase inhibitors

    PubMed Central

    Hui, Chunngai; Ye, Tao

    2015-01-01

    Lysine methyltransferase which catalyze methylation of histone and non-histone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery. PMID:26258118

  1. [ACE inhibitors and the kidney].

    PubMed

    Hörl, W H

    1996-01-01

    Treatment with ACE inhibitors results in kidney protection due to reduction of systemic blood pressure, intraglomerular pressure, an antiproliferative effect, reduction of proteinuria and a lipid-lowering effect in proteinuric patients (secondary due to reduction of protein excretion). Elderly patients with diabetes melitus, coronary heart disease or peripheral vascular occlusion are at risk for deterioration of kidney function due to a high frequency of renal artery stenosis in these patients. In patients with renal insufficiency dose reduction of ACE inhibitors is necessary (exception: fosinopril) but more important is the risk for development of hyperkalemia. Patients at risk for renal artery stenosis and patients pretreated with diuretics should receive a low ACE inhibitor dosage initially ("start low - go slow"). For compliance reasons once daily ACE inhibitor dosage is recommended.

  2. Thrombin Inhibitors from Different Animals

    PubMed Central

    Tanaka-Azevedo, A. M.; Morais-Zani, K.; Torquato, R. J. S.; Tanaka, A. S.

    2010-01-01

    Venous and arterial thromboembolic diseases are still the most frequent causes of death and disability in high-income countries. Clinical anticoagulants are inhibitors of enzymes involved in the coagulation pathway, such as thrombin and factor Xa. Thrombin is a key enzyme of blood coagulation system, activating the platelets, converting the fibrinogen to the fibrin net, and amplifying its self-generation by the activation of factors V, VIII, and XI. Thrombin has long been a target for the development of oral anticoagulants. Furthermore, selective inhibitors of thrombin represent a new class of antithrombotic agents. For these reasons, a number of specific thrombin inhibitors are under evaluation for possible use as antithrombotic drugs. This paper summarizes old and new interests of specific thrombin inhibitors described in different animals. PMID:20976270

  3. Histone deacetylase inhibitors modulate miRNA and mRNA expression, block metaphase, and induce apoptosis in inflammatory breast cancer cells.

    PubMed

    Chatterjee, Namita; Wang, Wei-Lin Winnie; Conklin, Tucker; Chittur, Sridar; Tenniswood, Martin

    2013-07-01

    To develop new therapies for inflammatory breast cancer (IBC) we have compared the effects of two hydroxamic acid-based histone deacetylase (HDAC) inhibitors, CG-1521 and Trichostatin A (TSA) on the biology of two IBC cell lines: SUM149PT and SUM190PT. CG-1521 and TSA induce dose (0-10 µM) and time-dependent (0-96 h) increases in the proportion of cells undergoing cell cycle arrest and apoptosis in the presence or absence of 17β-estradiol. In SUM 149PT cells, both CG-1521 and TSA increase the levels of acetylated α-tubulin; however the morphological effects are different: CG-1521 blocks mitotic spindle formation and prevents abscission during cytokinesis while TSA results in an increase in cell size. In SUM190PT cells CG-1521 does not cause an increase in acetylated-α-tubulin and even though TSA significantly increases the levels of acetylated tubulin, neither inhibitor alters the morphology of the cells. Microarray analysis demonstrates that CG-1521 modulates the expression of 876 mRNAs and 63 miRNAs in SUM149PT cells, and 1227 mRNAs and 35 miRNAs in SUM190PT cells. Only 9% of the genes are commonly modulated in both cell lines, suggesting that CG-1521 and TSA target different biological processes in the two cell lines most likely though the inhibition of different HDACs in these cell lines. Gene ontology (GO) analysis reveals that CG-1521 affects the expression of mRNAs that encode proteins associated with the spindle assembly checkpoint, chromosome segregation, and microtubule-based processes in both cell lines and has cell-type specific effects on lipid biosynthesis, response to DNA damage, and cell death.

  4. Synthesis of influenza neuraminidase inhibitors.

    PubMed

    Abdel-Magid, A F; Maryanoff, C A; Mehrman, S J

    2001-11-01

    Influenza neuraminidase inhibitors provide a means to combat flu, a potentially very serious disease. For the first time, there is a way to treat influenza by blocking the influenza enzyme neuraminidase to stop or slow the progression of infection. The diverse structures and synthesis of several influenza neuraminidase inhibitors are discussed. Contributions from chemical process development groups are highlighted for those compounds that have reached the market, such as zanamivir and oseltamivir phosphate.

  5. Inhibitors of pig kidney trehalase.

    PubMed

    Kyosseva, S V; Kyossev, Z N; Elbein, A D

    1995-02-01

    Trehazolin, a new trehalase inhibitor isolated from the culture broth of Micromonospora, was reported to be a highly specific inhibitor for porcine and silk worm trehalases with IC50 values of 5.5 x 10(-9) and 3.7 x 10(-9) M, respectively (O. Ando, H. Satake, K. Itoi, A. Sato, M. Nakajima, S. Takashi, H. Haruyama, Y. Ohkuma, T. Kinoshita, and R. Enokita (1991) J. Antibiot. 44, 1165-1168). We also found that trehazolin is a very powerful and quite specific inhibitor against purified pig kidney trehalase, giving an IC50 value of 1.9 x 10(-8) M. Lineweaver-Burk plots showed that this compound was a competitive inhibitor of the trehalase. However, even at concentrations of 200 micrograms/ml, trehazolin did not inhibit the rat intestinal maltase or sucrase, yeast alpha-glucosidase or almond beta-glucosidase. Validoxylamine A and validamycin A, two other trehalase inhibitors, showed potent competitive inhibition against purified pig kidney trehalase, with IC50 values of 2.4 x 10(-9) and 2.5 x 10(-4) M, respectively. On the other hand, validoxylamine A was almost inactive against rat intestinal sucrase and maltase, with some inhibition being observed at millimolar concentration. A number of other glucosidase inhibitors, such as MDL 25637, castanospermine, and deoxynojirimycin were also tested against the purified trehalase and showed reasonable inhibitory activity.

  6. ADAM17 Inhibitors Attenuate Corneal Epithelial Detachment Induced by Mustard Exposure.

    PubMed

    DeSantis-Rodrigues, Andrea; Chang, Yoke-Chen; Hahn, Rita A; Po, Iris P; Zhou, Peihong; Lacey, C Jeffrey; Pillai, Abhilash; C Young, Sherri; Flowers, Robert A; Gallo, Michael A; Laskin, Jeffrey D; Gerecke, Donald R; Svoboda, Kathy K H; Heindel, Ned D; Gordon, Marion K

    2016-04-01

    Sulfur mustard, nitrogen mustard (NM), and 2-chloroethyl ethyl sulfide all cause corneal injury with epithelial-stromal separation, differing only by degree. Injury can resolve in a few weeks or develop into chronic corneal problems. These vesicants induce microbullae at the epithelial-stromal junction, which is partially caused by cleavage of transmembranous hemidesmosomal collagen XVII, a component anchoring the epithelium to the stroma. ADAM17 is an enzyme involved in wound healing and is able to cleave collagen XVII. The activity of ADAM17 was inhibited in vesicant-exposed corneas by four different hydroxamates, to evaluate their therapeutic potential when applied 2 hours after exposure, thereby allowing ADAM17 to perform its early steps in wound healing. Rabbit corneal organ cultures exposed to NM for 2 hours were washed, then incubated at 37°C for 22 hours, with or without one of the four hydroxamates (dose range, 0.3-100 nmol in 20 μL, applied four times). Corneas were analyzed by light and immunofluorescence microscopy, and ADAM17 activity assays. Nitrogen mustard-induced corneal injury showed significant activation of ADAM17 levels accompanying epithelial-stromal detachment. Corneas treated with hydroxamates starting 2 hours post exposure showed a dose-dependent ADAM17 activity inhibition up to concentrations of 3 nmol. Of the four hydroxamates, NDH4417 (N-octyl-N-hydroxy-2-[4-hydroxy-3-methoxyphenyl] acetamide) was most effective for inhibiting ADAM17 and retaining epithelial-stromal attachment. Mustard exposure leads to corneal epithelial sloughing caused, in part, by the activation of ADAM17 at the epithelial-stromal junction. Select hydroxamate compounds applied 2 hours after NM exposure mitigated epithelial-stromal separation.

  7. ADAM17 Inhibitors Attenuate Corneal Epithelial Detachment Induced by Mustard Exposure

    PubMed Central

    DeSantis-Rodrigues, Andrea; Chang, Yoke-Chen; A. Hahn, Rita; P. Po, Iris; Zhou, Peihong; Lacey, C. Jeffrey; Pillai, Abhilash; C. Young, Sherri; A. Flowers II, Robert; A. Gallo, Michael; D. Laskin, Jeffrey; R. Gerecke, Donald; K. H. Svoboda, Kathy; D. Heindel, Ned; Gordon, Marion K.

    2016-01-01

    Purpose Sulfur mustard, nitrogen mustard (NM), and 2-chloroethyl ethyl sulfide all cause corneal injury with epithelial–stromal separation, differing only by degree. Injury can resolve in a few weeks or develop into chronic corneal problems. These vesicants induce microbullae at the epithelial–stromal junction, which is partially caused by cleavage of transmembranous hemidesmosomal collagen XVII, a component anchoring the epithelium to the stroma. ADAM17 is an enzyme involved in wound healing and is able to cleave collagen XVII. The activity of ADAM17 was inhibited in vesicant-exposed corneas by four different hydroxamates, to evaluate their therapeutic potential when applied 2 hours after exposure, thereby allowing ADAM17 to perform its early steps in wound healing. Methods Rabbit corneal organ cultures exposed to NM for 2 hours were washed, then incubated at 37°C for 22 hours, with or without one of the four hydroxamates (dose range, 0.3–100 nmol in 20 μL, applied four times). Corneas were analyzed by light and immunofluorescence microscopy, and ADAM17 activity assays. Results Nitrogen mustard–induced corneal injury showed significant activation of ADAM17 levels accompanying epithelial–stromal detachment. Corneas treated with hydroxamates starting 2 hours post exposure showed a dose-dependent ADAM17 activity inhibition up to concentrations of 3 nmol. Of the four hydroxamates, NDH4417 (N-octyl-N-hydroxy-2-[4-hydroxy-3-methoxyphenyl] acetamide) was most effective for inhibiting ADAM17 and retaining epithelial–stromal attachment. Conclusions Mustard exposure leads to corneal epithelial sloughing caused, in part, by the activation of ADAM17 at the epithelial–stromal junction. Select hydroxamate compounds applied 2 hours after NM exposure mitigated epithelial–stromal separation. PMID:27058125

  8. Provirus activation plus CD59 blockage triggers antibody-dependent complement-mediated lysis of latently HIV-1-infected cells.

    PubMed

    Lan, Jie; Yang, Kai; Byrd, Daniel; Hu, Ningjie; Amet, Tohti; Shepherd, Nicole; Desai, Mona; Gao, Jimin; Gupta, Samir; Sun, Yongtao; Yu, Qigui

    2014-10-01

    Latently HIV-1-infected cells are recognized as the last barrier toward viral eradication and cure. To purge these cells, we combined a provirus stimulant with a blocker of human CD59, a key member of the regulators of complement activation, to trigger Ab-dependent complement-mediated lysis. Provirus stimulants including prostratin and histone deacetylase inhibitors such as romidepsin and suberoylanilide hydroxamic acid activated proviruses in the latently HIV-1-infected T cell line ACH-2 as virion production and viral protein expression on the cell surface were induced. Romidepsin was the most attractive provirus stimulant as it effectively activated proviruses at nanomolar concentrations that can be achieved clinically. Antiretroviral drugs including two protease inhibitors (atazanavir and darunavir) and an RT inhibitor (emtricitabine) did not affect the activity of provirus stimulants in the activation of proviruses. However, saquinavir (a protease inhibitor) markedly suppressed virus production, although it did not affect the percentage of cells expressing viral Env on the cell surface. Provirus-activated ACH-2 cells expressed HIV-1 Env that colocalized with CD59 in lipid rafts on the cell surface, facilitating direct interaction between them. Blockage of CD59 rendered provirus-activated ACH-2 cells and primary human CD4(+) T cells that were latently infected with HIV-1 sensitive to Ab-dependent complement-mediated lysis by anti-HIV-1 polyclonal Abs or plasma from HIV-1-infected patients. Therefore, a combination of provirus stimulants with regulators of complement activation blockers represents a novel approach to eliminate HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

  9. Functional characterization of Candida albicans Hos2 histone deacetylase

    PubMed Central

    Karthikeyan, G; Paul-Satyaseela, Maneesh; Dhatchana Moorthy, Nachiappan; Gopalaswamy, Radha; Narayanan, Shridhar

    2014-01-01

    Candida albicans is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of  HOS2 (High Osmolarity  Sensitive) , a gene coding for fungal histone deacetylase from  C. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This  in  vitro enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity. PMID:25110576

  10. Engineering trypsin for inhibitor resistance.

    PubMed

    Batt, Anna R; St Germain, Commodore P; Gokey, Trevor; Guliaev, Anton B; Baird, Teaster

    2015-09-01

    The development of effective protease therapeutics requires that the proteases be more resistant to naturally occurring inhibitors while maintaining catalytic activity. A key step in developing inhibitor resistance is the identification of key residues in protease-inhibitor interaction. Given that majority of the protease therapeutics currently in use are trypsin-fold, trypsin itself serves as an ideal model for studying protease-inhibitor interaction. To test the importance of several trypsin-inhibitor interactions on the prime-side binding interface, we created four trypsin single variants Y39A, Y39F, K60A, and K60V and report biochemical sensitivity against bovine pancreatic trypsin inhibitor (BPTI) and M84R ecotin. All variants retained catalytic activity against small, commercially available peptide substrates [kcat /KM  = (1.2 ± 0.3) × 10(7) M(-1 ) s(-1) . Compared with wild-type, the K60A and K60V variants showed increased sensitivity to BPTI but less sensitivity to ecotin. The Y39A variant was less sensitive to BPTI and ecotin while the Y39F variant was more sensitive to both. The relative binding free energies between BPTI complexes with WT, Y39F, and Y39A were calculated based on 3.5 µs combined explicit solvent molecular dynamics simulations. The BPTI:Y39F complex resulted in the lowest binding energy, while BPTI:Y39A resulted in the highest. Simulations of Y39F revealed increased conformational rearrangement of F39, which allowed formation of a new hydrogen bond between BPTI R17 and H40 of the variant. All together, these data suggest that positions 39 and 60 are key for inhibitor binding to trypsin, and likely more trypsin-fold proteases.

  11. [Trypsin inhibitor from Gleditsia triacanthos L. seeds].

    PubMed

    Mosolov, V V; Kolosova, G V; Valueva, T A; Dronova, L A

    1982-05-01

    The trypsin inhibitor from Gleditsia triacanthos (L.) seeds was purified by affinity chromatography on a column with trypsin-Sepharose 4B. The isolated inhibitor is a single-chain protein with molecular weight of about 20 000. The inhibitor suppresses bovine trypsin at a molar rate of 1 : 1, but weakly inhibits chymotrypsin in a non-stoichiometric manner. Some properties of the isolated inhibitor closely resembled those of soybean trypsin inhibitor (Kunitz).

  12. [New anticoagulants - direct thrombin inhibitors].

    PubMed

    Brand, B; Graf, L

    2012-11-01

    Direct thrombin-inhibitors inactivate not only free but also fibrin-bound thrombin. The group of parenteral direct thrombin-inhibitors includes the recombinant hirudins lepirudin and desirudin, the synthetic hirudin bivalirudin, and the small molecule argatroban. All these compounds do not interact with PF4/heparin-antibodies. Therefore, argatroban as well as bivalirudin are currently used to treat heparin-induced thrombocytopenia (HIT). The oral direct thrombin-inhibitor dabigatran etexilate is already licensed in many countries for the treatment of non-valvular atrial fibrillation. Dabigatran etexilate reveals a stable and predictable effect that allows a medication without dose adjustment or monitoring. The substance shows only few interactions with other drugs but strong inhibitors of p-glycoprotein can increase plasma levels of dabigatran substantially. After oral intake, the prodrug dabigatran etexilate is cleaved by esterase-mediated hydrolyses to the active compound dabigatran. Elimination of dabigatran is predominantly renal. Safety and efficacy of dabigatran etexilate were tested in an extensive clinical study program. Non-inferiority compared to current standard treatments was shown for prophylaxis of venous thromboembolic events after total knee and hip replacement, for stroke prevention in atrial fibrillation, and for treatment of acute venous thromboembolism. In daily practice, Dabigatran etexilate competes against the new direct factor Xa-inhibitors. In the absence of direct comparative clinical trials, it is not yet clear if one class of substances has distinct advantages over the other.

  13. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  14. Electrochemical studies of corrosion inhibitors

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1990-01-01

    The effect of single salts, as well as multicomponent mixtures, on corrosion inhibition was studied for type 1010 steel; for 5052, 1100, and 2219-T87 aluminum alloys; and for copper. Molybdate-containing inhibitors exhibit an immediate, positive effect for steel corrosion, but an incubation period may be required for aluminum before the effect of a given inhibitor can be determined. The absence of oxygen was found to provide a positive effect (smaller corrosion rate) for steel and copper, but a negative effect for aluminum. This is attributed to the two possible mechanisms by which aluminum can oxidize. Corrosion inhibition is generally similar for oxygen-rich and oxygen-free environments. The results show that the electrochemical method is an effective means of screening inhibitors for the corrosion of single metals, with caution to be exercised in the case of aluminum.

  15. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, Joanna S.; MacGregor, Robert R.; Wolf, Alfred P.; Langstrom, Bengt

    1990-01-01

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  16. An environmentally friendly scale inhibitor

    SciTech Connect

    Dobbs, J.B.; Brown, J.M.

    1999-11-01

    This paper describes a method of inhibiting the formation of scales such as barium and strontium sulfate in low pH aqueous systems, and calcium carbonate in systems containing high concentrations of dissolved iron. The solution, chemically, involves treating the aqueous system with an inhibitor designed to replace organic-phosphonates. Typical low pH aqueous systems where the inhibitor is particularly useful are oilfield produced-water, resin bed water softeners that form scale during low pH, acid regeneration operations. Downhole applications are recommended where high concentrations of dissolved iron are present in the produced water. This new approach to inhibition replaces typical organic phosphonates and polymers with a non-toxic, biodegradable scale inhibitor that performs in harsh environments.

  17. Positron emitter labeled enzyme inhibitors

    SciTech Connect

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-04-03

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  18. Coking products as corrosion inhibitors

    SciTech Connect

    Antonov, A.V.; Petrenko, V.G.; Frolova, R.P.; Kurinnaya, S.N.

    1982-11-06

    Activated sludge and froth from the biological treatment of coke plant waste waters has been determined to be a corrosion inhibitor in both neutral and acidic media, due to the presence of unreacted coking derived inhibitors, bacteriological formation of inhibitors, bacterial organisms, humic-type organics and traces of germanium, zinc, mercury and manganese. The corrosive liquids tested were, river water, technical system water, gas cooler aqueous condensate, gas collector condensate and coking waste water before and after treatment, the substrate being St 3 steel plates (45 X 45 X 5 M) (time 24-30 hr (acid media) and 934 hr (neutral media)). The activated sludge (25 g/l) reduced acid media corrosion rate by 10/sup 3/, the protective effect being 99% for the test liquids: Sludge is more effective than the froth.

  19. Corrosion inhibitors from expired drugs.

    PubMed

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra

    2012-07-15

    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%.

  20. STAT inhibitors for cancer therapy

    PubMed Central

    2013-01-01

    Signal Transducer and Activator of Transcription (STAT) proteins are a family of cytoplasmic transcription factors consisting of 7 members, STAT1 to STAT6, including STAT5a and STAT5b. STAT proteins are thought to be ideal targets for anti-cancer therapy since cancer cells are more dependent on the STAT activity than their normal counterparts. Inhibitors targeting STAT3 and STAT5 have been developed. These included peptidomimetics, small molecule inhibitors and oligonucleotides. This review summarized advances in preclinical and clinical development of these compounds. PMID:24308725

  1. [Kinase inhibitors against hematological malignancies].

    PubMed

    Tojo, Arinobu

    2014-06-01

    Dysregulation of protein phosphorylation, especially on tyrosine residues, plays a crucial role in development and progression of hematological malignancies. Since remarkable success in imatinib therapy of CML and Ph+ALL, extensive efforts have made to explore candidate molecular targets and next breakthrough drugs. Now that next generation ABL kinase inhibitors are available for CML, the therapeutic algorithm has been revolutionized. As for AML and lymphoid malignancies, many kinase inhibitors targeting FLT3, BTK and aurora-A are on early and late clinical trials, and a number of promising drugs including ibrutinib are picked up for further evaluation.

  2. EGFR inhibitors and autophagy in cancer treatment.

    PubMed

    Cui, Jie; Hu, Yun-Feng; Feng, Xie-Min; Tian, Tao; Guo, Ya-Huan; Ma, Jun-Wei; Nan, Ke-Jun; Zhang, Hong-Yi

    2014-12-01

    Epidermal growth factor receptor (EGFR) inhibitor treatment is a strategy for cancer therapy. However, innate and acquired resistance is a major obstacle of the efficacy. Autophagy is a self-digesting process in cells, which is considered to be associated with anti-cancer drug resistance. The activation of EGFR can regulate autophagy through multiple signal pathways. EGFR inhibitors can induce autophagy, but the specific function of the induction of autophagy by EGFR inhibitors remains biphasic. On the one hand, autophagy induced by EGFR inhibitors acts as a cytoprotective response in cancer cells, and autophagy inhibitors can enhance the cytotoxic effects of EGFR inhibitors. On the other hand, a high level of autophagy after treatment of EGFR inhibitors can also result in autophagic cell death lacking features of apoptosis, and the combination of EGFR inhibitors with an autophagy inducer might be beneficial. Thus, autophagy regulation represents a promising approach for improving the efficacy of EGFR inhibitors in the treatment of cancer patients.

  3. Structure based design of novel 6,5 heterobicyclic mitogen-activated protein kinase kinase (MEK) inhibitors leading to the discovery of imidazo[1,5-a] pyrazine G-479.

    PubMed

    Robarge, Kirk D; Lee, Wendy; Eigenbrot, Charles; Ultsch, Mark; Wiesmann, Christian; Heald, Robert; Price, Steve; Hewitt, Joanne; Jackson, Philip; Savy, Pascal; Burton, Brenda; Choo, Edna F; Pang, Jodie; Boggs, Jason; Yang, April; Yang, Xioaye; Baumgardner, Matthew

    2014-10-01

    Use of the tools of SBDD including crystallography led to the discovery of novel and potent 6,5 heterobicyclic MEKi's [J. Med. Chem.2012, 55, 4594]. The core change from a 5,6 heterobicycle to a 6,5 heterobicycle was driven by the desire for increased structural diversity and aided by the co-crystal structure of G-925 [J. Med. Chem.2012, 55, 4594]. The key design feature was the shift of the attachment of the five-membered heterocyclic ring towards the B ring while maintaining the key hydroxamate and anilino pharamcophoric elements in a remarkably similar position as in G-925. From modelling, changing the connection point of the five membered ring heterocycle placed the H-bond accepting nitrogen within a good distance and angle to the Ser212 [J. Med. Chem.2012, 55, 4594]. The resulting novel 6,5 benzoisothiazole MEKi G-155 exhibited improved potency versus aza-benzofurans G-925 and G-963 but was a potent inhibitor of cytochrome P450's 2C9 and 2C19. Lowering the logD by switching to the more polar imidazo[1,5-a] pyridine core significantly diminished 2C9/2C19 inhibition while retaining potency. The imidazo[1,5-a] pyridine G-868 exhibited increased potency versus the starting point for this work (aza-benzofuran G-925) leading to deprioritization of the azabenzofurans. The 6,5-imidazo[1,5-a] pyridine scaffold was further diversified by incorporating a nitrogen at the 7 position to give the imidazo[1,5-a] pyrazine scaffold. The introduction of the C7 nitrogen was driven by the desire to improve metabolic stability by blocking metabolism at the C7 and C8 positions (particularly the HLM stability). It was found that improving on G-868 (later renamed GDC-0623) required combining C7 nitrogen with a diol hydroxamate to give G-479. G-479 with polarity distributed throughout the molecule was improved over G-868 in many aspects.

  4. Evaluation of 6-([18F] fluoroacetamido)-1-hexanoic-anilide (18F-FAHA) as imaging probe in tumor xenograft mice model

    NASA Astrophysics Data System (ADS)

    Li, Fiona; Cho, Sung Ju; Yu, Lihai; Hudson, Robert H. E.; Luyt, Leonard G.; Pin, Christopher L.; Kovacs, Michael S.; Koropatnick, James; Lee, Ting-Yim

    2016-03-01

    Alteration in genetic expression is as important as gene mutation in cancer development and proliferation. Epigenetic changes affect gene expression without altering the DNA sequence. Histone deacetylase (HDAC), an enzyme facilitating histone remodelling, can lead to silencing of tumor suppressor genes making HDAC inhibitors viable anticancer drugs against tumors with increased activity of the enzyme. In this study we evaluated 18F-fluroacetamido-1-hexanoicanilide (18F-FAHA), an artificial HDAC substrate, as imaging probe of HDAC activity of human tumor xenografts in immunocompromised host mice. Human breast and melanoma cell lines, MDA-MB-468 and MDA-MB-435 respectively, known to overexpress HDAC activity were xenografted into immunocompromised mice and HDAC activity was imaged using 18F-FAHA. The melanoma group was treated with saline, SAHA (suberoylanilide hydroxamic acid, an approved anticancer HDAC inhibitor) in DMSO, or DMSO as positive control. Tracer kinetic modelling and SUV were used to estimate HDAC activity from dynamic PET data. Both breast tumor and melanoma group showed great variability in binding rate constant (BRC) of 18F-FAHA suggesting highly variable inter- and intra-tumoral HDAC activity. For the SAHA treated melanoma group, HDAC activity, as monitored by BRC of 18F-FAHA, decreased more than the two (positive and negative) control groups but not tumor growth. Our preliminary study showed that noninvasive PET imaging with 18F-FAHA has the potential to identify patients for whom treatment with HDAC inhibitors are appropriate, to assess the effectiveness of that treatment as an early marker of target reduction, and also eliminate the need for invasive tissue biopsy to individualize treatment.

  5. Isobolographic analysis demonstrates additive effect of cisplatin and HDIs combined treatment augmenting their anti-cancer activity in lung cancer cell lines

    PubMed Central

    Gumbarewicz, Ewelina; Luszczki, Jarogniew J; Wawruszak, Anna; Dmoszynska-Graniczka, Magdalena; Grabarska, Aneta J; Jarząb, Agata M; Polberg, Krzysztof; Stepulak, Andrzej

    2016-01-01

    Histone deacetylase inhibitors (HDIs) are a new class of drugs which affect the activity of HDACs resulting in changed of acetylation in many proteins. HDIs can induce differentiation, cell growth arrest, apoptosis, inhibit proliferation and angiogenesis in cancer, whereas normal cells are comparatively resistant to the action of HDIs. The aim of this study was to investigate the combined effect of a well-known cytostatic agent-cisplatin (CDDP) and a histone deacetylase inhibitors-either suberoylanilide hydroxamic acid (SAHA, vorinostat) or valproic acid (VPA), on the proliferation of lung cancer cells, as well as induction of apoptosis and inhibition of the cell cycle progression. The anti-proliferative activity of VPA or SAHA used alone, or in combination with CDDP were determined by means of MTT test. The type of pharmacologic interactions between HDAC inhibitors and CDDP was assessed using isobolographic analysis. We observed additive interactions for the CCDP with SAHA, as well as for the CDDP with VPA combinations with respect to their anti-proliferative effects on three different lung cancer cell lines (A549, NCI-H1563 and NCI-H2170). Such additive effects were observed regardless of the histologic type (adenocarcinoma or squamous cell carcinoma) and sensitivity for the drugs applied. Combination treatment also augmented the induction of apoptosis and cell cycle perturbation mediated by CDDP alone, thereby enhancing anti-cancer effect of tested drugs. In conclusion, the combined therapy of HDIs and CDDP may be a promising therapeutic tool in the treatment of lung cancer. PMID:28042503

  6. Histone deacetylase enzymes as drug targets for the control of the sheep blowfly, Lucilia cuprina

    PubMed Central

    Kotze, Andrew C.; Hines, Barney M.; Bagnall, Neil H.; Anstead, Clare A.; Gupta, Praveer; Reid, Robert C.; Ruffell, Angela P.; Fairlie, David P.

    2015-01-01

    The Australian sheep blowfly, Lucilia cuprina, is an ecto-parasite that causes significant economic losses in the sheep industry. Emerging resistance to insecticides used to protect sheep from this parasite is driving the search for new drugs that act via different mechanisms. Inhibitors of histone deacetylases (HDACs), enzymes essential for regulating eukaryotic gene transcription, are prospective new insecticides based on their capacity to kill human parasites. The blowfly genome was found here to contain five HDAC genes corresponding to human HDACs 1, 3, 4, 6 and 11. The catalytic domains of blowfly HDACs 1 and 3 have high sequence identity with corresponding human and other Dipteran insect HDACs (Musca domestica and Drosophila melanogaster). On the other hand, HDACs 4, 6 and 11 from the blowfly and the other Dipteran species showed up to 53% difference in catalytic domain amino acids from corresponding human sequences, suggesting the possibility of developing HDAC inhibitors specific for insects as desired for a commercial insecticide. Differences in transcription patterns for different blowfly HDACs through the life cycle, and between the sexes of adult flies, suggest different functions in regulating gene transcription within this organism and possibly different vulnerabilities. Data that supports HDACs as possible new insecticide targets is the finding that trichostatin A and suberoylanilide hydroxamic acid retarded growth of early instar blowfly larvae in vitro, and reduced the pupation rate. Trichostatin A was 8-fold less potent than the commercial insecticide cyromazine in inhibiting larval growth. Our results support further development of inhibitors of blowfly HDACs with selectivity over human and other mammalian HDACs as a new class of prospective insecticides for sheep blowfly. PMID:27120067

  7. Regulation of acetylation restores proteolytic function of diseased myocardium in mouse and human.

    PubMed

    Wang, Ding; Fang, Caiyun; Zong, Nobel C; Liem, David A; Cadeiras, Martin; Scruggs, Sarah B; Yu, Hongxiu; Kim, Allen K; Yang, Pengyuan; Deng, Mario; Lu, Haojie; Ping, Peipei

    2013-12-01

    Proteasome complexes play essential roles in maintaining cellular protein homeostasis and serve fundamental roles in cardiac function under normal and pathological conditions. A functional detriment in proteasomal activities has been recognized as a major contributor to the progression of cardiovascular diseases. Therefore, approaches to restore proteolytic function within the setting of the diseased myocardium would be of great clinical significance. In this study, we discovered that the cardiac proteasomal activity could be regulated by acetylation. Histone deacetylase (HDAC) inhibitors (suberoylanilide hydroxamic acid and sodium valproate) enhanced the acetylation of 20S proteasome subunits in the myocardium and led to an elevation of proteolytic capacity. This regulatory paradigm was present in both healthy and acutely ischemia/reperfusion (I/R) injured murine hearts, and HDAC inhibition in vitro restored proteolytic capacities to baseline sham levels in injured hearts. This mechanism of regulation was also viable in failing human myocardium. With 20S proteasomal complexes purified from murine myocardium treated with HDAC inhibitors in vivo, we confirmed that acetylation of 20S subunits directly, at least in part, presents a molecular explanation for the improvement in function. Furthermore, using high-resolution LC-MS/MS, we unraveled the first cardiac 20S acetylome, which identified the acetylation of nine N-termini and seven internal lysine residues. Acetylation on four lysine residues and four N-termini on cardiac proteasomes were novel discoveries of this study. In addition, the acetylation of five lysine residues was inducible via HDAC inhibition, which correlated with the enhancement of 20S proteasomal activity. Taken as a whole, our investigation unveiled a novel mechanism of proteasomal function regulation in vivo and established a new strategy for the potential rescue of compromised proteolytic function in the failing heart using HDAC inhibitors.

  8. Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

    PubMed Central

    Čolović, Mirjana B; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M

    2013-01-01

    Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer’s disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases. PMID:24179466

  9. Natural Inhibitors of Maillard Browning

    DTIC Science & Technology

    2013-12-01

    development for ration and commercial items that deteriorate from Maillard browning effects while in storage. Figure 15: Avocado 96 h after being...MAILLARD BROWNING by Nicole Favreau Farhadi Lauren Pecukonis and Jacqueline LeBlanc December 2013 Final Report...2009- September 2011 4. TITLE AND SUBTITLE NATURAL INHIBITORS OF MAILLARD BROWNING 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  10. Less-toxic corrosion inhibitors

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1981-01-01

    Combinations of borates, nitrates, phosphates, silicates, and sodium MBT protect aluminum from corrosion in fresh water. Most effective combinations contained sodium phosphate and were alkaline. These inhibitors replace toxic chromates which are subject to governmental restrictions, but must be used in larger quantities. Experimental exposure times varied from 1 to 14 months depending upon nature of submersion solution.

  11. Azidoblebbistatin, a photoreactive myosin inhibitor

    PubMed Central

    Képiró, Miklós; Várkuti, Boglárka H.; Bodor, Andrea; Hegyi, György; Drahos, László; Kovács, Mihály; Málnási-Csizmadia, András

    2012-01-01

    Photoreactive compounds are important tools in life sciences that allow precisely timed covalent crosslinking of ligands and targets. Using a unique technique we have synthesized azidoblebbistatin, which is a derivative of blebbistatin, the most widely used myosin inhibitor. Without UV irradiation azidoblebbistatin exhibits identical inhibitory properties to those of blebbistatin. Using UV irradiation, azidoblebbistatin can be covalently crosslinked to myosin, which greatly enhances its in vitro and in vivo effectiveness. Photo-crosslinking also eliminates limitations associated with the relatively low myosin affinity and water solubility of blebbistatin. The wavelength used for photo-crosslinking is not toxic for cells and tissues, which confers a great advantage in in vivo tests. Because the crosslink results in an irreversible association of the inhibitor to myosin and the irradiation eliminates the residual activity of unbound inhibitor molecules, azidoblebbistatin has a great potential to become a highly effective tool in both structural studies of actomyosin contractility and the investigation of cellular and physiological functions of myosin II. We used azidoblebbistatin to identify previously unknown low-affinity targets of the inhibitor (EC50 ≥ 50 μM) in Dictyostelium discoideum, while the strongest interactant was found to be myosin II (EC50 = 5 μM). Our results demonstrate that azidoblebbistatin, and potentially other azidated drugs, can become highly useful tools for the identification of strong- and weak-binding cellular targets and the determination of the apparent binding affinities in in vivo conditions. PMID:22647605

  12. Benzimidazole derivatives as kinase inhibitors.

    PubMed

    Garuti, Laura; Roberti, Marinella; Bottegoni, Giovanni

    2014-01-01

    Benzimidazole is a common kinase inhibitor scaffold and benzimidazole-based compounds interact with enzymes by multiple binding modes. In some cases, the benzimidazole acts as part of the hinge-binding motif, in others it has a scaffolding role without evidence for direct hinge binding. Several of these compounds are ATP-competitive inhibitors and show high selectivity by exploiting unique structural properties that distinguish one kinase from the majority of other kinases. However, the high specificity for a single target is not always sufficient. Thus another approach, called multi-target therapy, has been developed over the last few years. The simultaneous inhibition of various kinases may be useful because the disease is attacked at several relevant targets. Moreover, if a kinase becomes drug-resistant, a multitargeted drug can act on the other kinases. Some benzimidazole derivatives are multi-target inhibitors. In this article benzimidazole inhibitors are reported with their mechanisms of action, structure-activity relationship (SAR) and biological properties.

  13. Biocatalysts with enhanced inhibitor tolerance

    DOEpatents

    Yang, Shihui; Linger, Jeffrey; Franden, Mary Ann; Pienkos, Philip T.; Zhang, Min

    2015-12-08

    Disclosed herein are biocatalysts for the production of biofuels, including microorganisms that contain genetic modifications conferring tolerance to growth and fermentation inhibitors found in many cellulosic feedstocks. Methods of converting cellulose-containing materials to fuels and chemicals, as well as methods of fermenting sugars to fuels and chemicals, using these biocatalysts are also disclosed.

  14. Biological abatement of cellulase inhibitors.

    PubMed

    Cao, Guangli; Ximenes, Eduardo; Nichols, Nancy N; Zhang, Leyu; Ladisch, Michael

    2013-10-01

    Removal of enzyme inhibitors released during lignocellulose pretreatment is essential for economically feasible biofuel production. We tested bio-abatement to mitigate enzyme inhibitor effects observed in corn stover liquors after pretreatment with either dilute acid or liquid hot water at 10% (w/v) solids. Bio-abatement of liquors was followed by enzymatic hydrolysis of cellulose. To distinguish between inhibitor effects on enzymes and recalcitrance of the substrate, pretreated corn stover solids were removed and replaced with 1% (w/v) Solka Floc. Cellulose conversion in the presence of bio-abated liquors from dilute acid pretreatment was 8.6% (0.1x enzyme) and 16% (1x enzyme) higher than control (non-abated) samples. In the presence of bio-abated liquor from liquid hot water pretreated corn stover, 10% (0.1x enzyme) and 13% (1x enzyme) higher cellulose conversion was obtained compared to control. Bio-abatement yielded improved enzyme hydrolysis in the same range as that obtained using a chemical (overliming) method for mitigating inhibitors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Inhibitor Discovery by Convolution ABPP.

    PubMed

    Chandrasekar, Balakumaran; Hong, Tram Ngoc; van der Hoorn, Renier A L

    2017-01-01

    Activity-based protein profiling (ABPP) has emerged as a powerful proteomic approach to study the active proteins in their native environment by using chemical probes that label active site residues in proteins. Traditionally, ABPP is classified as either comparative or competitive ABPP. In this protocol, we describe a simple method called convolution ABPP, which takes benefit from both the competitive and comparative ABPP. Convolution ABPP allows one to detect if a reduced signal observed during comparative ABPP could be due to the presence of inhibitors. In convolution ABPP, the proteomes are analyzed by comparing labeling intensities in two mixed proteomes that were labeled either before or after mixing. A reduction of labeling in the mix-and-label sample when compared to the label-and-mix sample indicates the presence of an inhibitor excess in one of the proteomes. This method is broadly applicable to detect inhibitors in proteomes against any proteome containing protein activities of interest. As a proof of concept, we applied convolution ABPP to analyze secreted proteomes from Pseudomonas syringae-infected Nicotiana benthamiana leaves to display the presence of a beta-galactosidase inhibitor.

  16. Acetylcholinesterase inhibitors: pharmacology and toxicology.

    PubMed

    Colović, Mirjana B; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M

    2013-05-01

    Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer's disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases.

  17. Phosphodiesterase inhibitors: history of pharmacology.

    PubMed

    Schudt, Christian; Hatzelmann, Armin; Beume, Rolf; Tenor, Hermann

    2011-01-01

    The first pharmacological investigations of phosphodiesterase (PDE) inhibitors were developed with the clinical efficacies of drugs isolated from coffee, cacao and tea but only later their relevant ingredients were identified as xanthines that act as PDE. With its diuretic, inotropic and bronchodilating clinical efficacy, use of theophylline anticipated the clinical goals, which were later approached with the first-generation of weakly selective PDE inhibitors in the period from 1980 to 1990. Pharmacological and clinical research with these early compounds provided a vast pool of information regarding desired and adverse actions - although most of these new drugs had to be discontinued due to severe adverse effects. The pharmacological models for cardiac, vascular and respiratory indications were analysed for their PDE isoenzyme profiles, and when biochemical and molecular biological approaches expanded our knowledge of the PDE superfamily, the purified isoenzymes that were now available opened the door for more systematic studies of inhibitors and for generation of highly selective isoenzyme-specific drugs. The development of simple screening models and clinically relevant indication models reflecting the growing knowledge about pathomechanisms of disease are summarised here for today's successful application of highly selective PDE3, PDE4 and PDE5 inhibitors. The interplay of serendipitous discoveries, the establishment of intelligent pharmacological models and the knowledge gain by research results with new substances is reviewed. The broad efficacies of new substances in vitro, the enormous biodiversity of the PDE isoenzyme family and the sophisticated biochemical pharmacology enabled Viagra to be the first success story in the field of PDE inhibitor drug development, but probably more success stories will follow.

  18. Proteinase inhibitors from the medicinal leech Hirudo medicinalis.

    PubMed

    Baskova, I P; Zavalova, L L

    2001-07-01

    The medicinal leech Hirudo medicinalis produces various types of proteinase inhibitors: bdellins (inhibitors of trypsin, plasmin, and acrosin), hirustasin (inhibitor of tissue kallikrein, trypsin, alpha-chymotrypsin, and granulocyte cathepsin G), tryptase inhibitor, eglins (inhibitors of alpha-chymotrypsin, subtilisin, and chymasin and the granulocyte proteinases elastase and cathepsin G), inhibitor of factor Xa, hirudin (thrombin inhibitor), inhibitor of carboxypeptidase, and inhibitor of complement component C1s. This review summarizes data on their primary and tertiary structures, action mechanisms, and biological activities.

  19. Proton pump inhibitor-induced hypomagnesemic hypoparathyroidism.

    PubMed

    Swaminathan, Krishnan

    2015-01-01

    Proton pump inhibitors are the one of the most widely used drugs in the world. Hypomagnesemic hypoparathyroidism has been reported with different proton pump inhibitors with prolonged oral use. We report the first reported case of possible such effect with intravenous preparation of proton pump inhibitor. This case report raises awareness among physicians worldwide of this often unknown association, as life-threatening cardiac and neuromuscular complications can arise with unrecognized hypocalcemia and hypomagnesemia with proton pump inhibitors.

  20. Proton pump inhibitor-induced hypomagnesemic hypoparathyroidism

    PubMed Central

    Swaminathan, Krishnan

    2015-01-01

    Proton pump inhibitors are the one of the most widely used drugs in the world. Hypomagnesemic hypoparathyroidism has been reported with different proton pump inhibitors with prolonged oral use. We report the first reported case of possible such effect with intravenous preparation of proton pump inhibitor. This case report raises awareness among physicians worldwide of this often unknown association, as life-threatening cardiac and neuromuscular complications can arise with unrecognized hypocalcemia and hypomagnesemia with proton pump inhibitors. PMID:26069375

  1. Synthesis, siderophore activity and iron(III) chelation chemistry of a novel mono-hydroxamate, bis-catecholate siderophore mimic: N(alpha),-N(epsilon)-Bis[2,3-dihydroxybenzoyl]-l-lysyl-(gamma-N-methyl-N-hydroxyamido)-L-glutamic acid.

    PubMed

    Mies, Kassy A; Gebhardt, Peter; Möllmann, Ute; Crumbliss, Alvin L

    2008-04-01

    The synthesis and characterization of a novel tripodal mono-hydroxamate, bis catecholate siderophore mimic, N(alpha),-N(epsilon)-bis[2,3-dihydroxybenzoyl]-l-lysyl-(gamma-N-methyl-N-hydroxyamido)-l-glutamic acid (H(6)L), is described. The structure of H(6)L was established by 2D NMR and mass spectrometry. The chelation chemistry of H(6)L with respect to iron(III) is characterized in aqueous solution through determination of ligand pK(a) values and iron(III) binding constants using spectrophotometric and potentiometric titration techniques. Proton dependent iron(III)-ligand equilibrium constants were determined using a model based on the sequential protonation of the iron(III)-siderophore complex. These results were used to calculate the pH dependent speciation, the overall formation constant logbeta(110) (31.4) and pM value (18.3) for H(6)L with iron(III). The ability of H(6)L to deliver the essential nutrient iron to living cells is determined through growth promotion assays using various bacterial strains.

  2. Salicylanilide Inhibitors of Toxoplasma gondii

    PubMed Central

    Fomovska, Alina; Wood, Richard D.; Mui, Ernest; Dubey, Jitenter P.; Ferriera, Leandra R.; Hickman, Mark R.; Lee, Patricia J.; Leed, Susan E.; Auschwitz, Jennifer M.; Welsh, William J.; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-01-01

    Toxoplasma gondii(T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose anti-apicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles. PMID:22970937

  3. Salicylanilide inhibitors of Toxoplasma gondii.

    PubMed

    Fomovska, Alina; Wood, Richard D; Mui, Ernest; Dubey, Jitenter P; Ferreira, Leandra R; Hickman, Mark R; Lee, Patricia J; Leed, Susan E; Auschwitz, Jennifer M; Welsh, William J; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-10-11

    Toxoplasma gondii (T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose antiapicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles.

  4. Small-molecule arginase inhibitors.

    PubMed

    Ivanenkov, Yan A; Chufarova, Nina V

    2014-01-01

    Arginase is an enzyme that metabolizes L-arginine to L-ornithine and urea. In addition to its fundamental role in the hepatic ornithine cycle, it also influences the immune systems in humans and mice. Arginase participates in many inflammatory disorders by decreasing the synthesis of nitric oxide and inducing fibrosis and tissue regeneration. L-arginine deficiency, which is modulated by myeloid cell arginase, suppresses T-cell immune response. This mechanism plays a fundamental role in inflammation-associated immunosuppression. Pathogens can synthesize their own arginase to elude immune reaction. Small-molecule arginase inhibitors are currently described as promising therapeutics for the treatment of several diseases, including allergic asthma, inflammatory bowel disease, ulcerative colitis, cardiovascular diseases (atherosclerosis and hypertension), diseases associated with pathogens (e.g., Helicobacter pylori, Trypanosoma cruzi, Leishmania, Mycobacterium tuberculosis and Salmonella), cancer and induced or spontaneous immune disorders. This article summarizes recent patents in the area of arginase inhibitors and discusses their properties.

  5. Pharmacogenomics and histone deacetylase inhibitors.

    PubMed

    Goey, Andrew Kl; Sissung, Tristan M; Peer, Cody J; Figg, William D

    2016-11-01

    The histone deacetylase inhibitor valproic acid (VPA) has been used for many decades in neurology and psychiatry. The more recent introduction of the histone deacetylase inhibitors (HDIs) belinostat, romidepsin and vorinostat for treatment of hematological malignancies indicates the increasing popularity of these agents. Belinostat, romidepsin and vorinostat are metabolized or transported by polymorphic enzymes or drug transporters. Thus, genotype-directed dosing could improve pharmacotherapy by reducing the risk of toxicities or preventing suboptimal treatment. This review provides an overview of clinical studies on the effects of polymorphisms on the pharmacokinetics, efficacy or toxicities of HDIs including belinostat, romidepsin, vorinostat, panobinostat, VPA and a number of novel compounds currently being tested in Phase I and II trials. Although pharmacogenomic studies for HDIs are scarce, available data indicate that therapy with belinostat (UGT1A1), romidepsin (ABCB1), vorinostat (UGT2B17) or VPA (UGT1A6) could be optimized by upfront genotyping.

  6. The novel histone deacetylase inhibitor, LBH589, induces expression of DNA damage response genes and apoptosis in Ph- acute lymphoblastic leukemia cells.

    PubMed

    Scuto, Anna; Kirschbaum, Mark; Kowolik, Claudia; Kretzner, Leo; Juhasz, Agnes; Atadja, Peter; Pullarkat, Vinod; Bhatia, Ravi; Forman, Stephen; Yen, Yun; Jove, Richard

    2008-05-15

    We investigated the mechanism of action of LBH589, a novel broad-spectrum HDAC inhibitor belonging to the hydroxamate class, in Philadelphia chromosome-negative (Ph(-)) acute lymphoblastic leukemia (ALL). Two model human Ph(-) ALL cell lines (T-cell MOLT-4 and pre-B-cell Reh) were treated with LBH589 and evaluated for biologic and gene expression responses. Low nanomolar concentrations (IC(50): 5-20 nM) of LBH589 induced cell-cycle arrest, apoptosis, and histone (H3K9 and H4K8) hyperacetylation. LBH589 treatment increased mRNA levels of proapoptosis, growth arrest, and DNA damage repair genes including FANCG, FOXO3A, GADD45A, GADD45B, and GADD45G. The most dramatically expressed gene (up to 45-fold induction) observed after treatment with LBH589 is GADD45G. LBH589 treatment was associated with increased histone acetylation at the GADD45G promoter and phosphorylation of histone H2A.X. Furthermore, treatment with LBH589 was active against cultured primary Ph(-) ALL cells, including those from a relapsed patient, inducing loss of cell viability (up to 70%) and induction of GADD45G mRNA expression (up to 35-fold). Thus, LBH589 possesses potent growth inhibitory activity against including Ph(-) ALL cells associated with up-regulation of genes critical for DNA damage response and growth arrest. These findings provide a rationale for exploring the clinical activity of LBH589 in the treatment of patients with Ph(-) ALL.

  7. Kinase Inhibitors from Marine Sponges

    PubMed Central

    Skropeta, Danielle; Pastro, Natalie; Zivanovic, Ana

    2011-01-01

    Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included. PMID:22073013

  8. Nelfinavir: fourth protease inhibitor approved.

    PubMed

    1997-01-01

    The Food and Drug Administration (FDA) has granted accelerated approval to nelfinavir in both adult and pediatric formulations. Agouron, the manufacturer, used innovative computerized drug design techniques to discover, design, and refine the nelfinavir molecule. Nelfinavir is marketed under the trade name Viracept, and costs $5,000 per year. Early clinical trials find it to be as powerful as the other protease inhibitors, but with a different resistance profile. The drug has relatively few drug indications; however, several compounds have been contraindicated.

  9. Voglibose: An Alpha Glucosidase Inhibitor

    PubMed Central

    Dabhi, Ajay S.; Bhatt, Nikita R.; Shah, Mohit J.

    2013-01-01

    Diabetes Mellitus (DM) is a morbid disease worldwide, with increasing incidence as time passes. It has macro-vascular and micro-vascular complications. The main cause of these complications is poorly controlled postprandial hyperglycaemia. Alpha glucosidase inhibitors, namely acarbose, voglibose and miglitol, are available for therapy. Voglibose is well tolerated and effective in comparable doses among these drugs. This article highlights the important features of voglibose. PMID:24551718

  10. Recent progress on fucosyltransferase inhibitors.

    PubMed

    Merino, Pedro; Tejero, Tomás; Delso, Ignacio; Hurtado-Guerrero, Ramon; Gómez-SanJuan, Asier; Sádaba, David

    2012-12-01

    Fucosyltransferases (FucTs) are enzymes that transfer L-fucose from GDP-fucose to a glycoside or a peptide. They have important roles in a variety of diseases including cancer and autoimmune disorders, viral and bacterial infections and inflammatory processes, and thus they represent important drug targets for the development of agents for the treatment of such disorders. This review highlights recent developments regarding carbohydrate mimics as inhibitors of FucTs. The most recent and relevant synthetic strategies are described.

  11. Pharmacology of HIV Integrase Inhibitors

    PubMed Central

    Adams, Jessica L; Greener, Benjamin N; Kashuba, Angela DM

    2013-01-01

    Purpose of Review The purpose of this paper is to review recent and relevant pharmacology data for three HIV integrase inhibitors: raltegravir (marketed), dolutegravir and elvitegravir (both in Phase III drug development). Recent Findings Data from January 2011 to April 2012 were evaluated. These data better characterized integrase inhibitor pharmacokinetics, assessed dosing regimens and investigated previously undescribed drug-drug interactions. Due to formulation challenges, raltegravir inter- and intra-patient pharmacokinetic variability is high. Twice daily 400mg dosing has been shown to be clinically superior to 800mg once daily dosing. A pediatric formulation of raltegravir with less variable pharmacokinetics and greater bioavailability was FDA approved in December 2011. Cobicistat-boosted elvitegravir, and the second generation integrase inhibitor dolutegravir, have lower pharmacokinetic variability and are dosed once daily. Dolutegravir drug interactions are similar to raltegravir, while boosted elvitegravir participates in additional CYP3A mediated interactions. Summary Raltegravir’s potent antiretroviral activity has resulted in widespread use in both treatment naïve and experienced patients. Dolutegravir and cobicistat-boosted elvitegravir have some pharmacokinetic advantages. Pharmacokinetic data in special populations (pregnancy, pediatrics) to optimize dosing are still required. PMID:22789987

  12. Substituted androstanes as aromatase inhibitors

    NASA Astrophysics Data System (ADS)

    Levina, Inna S.

    1998-11-01

    The synthesis and structure-activity relationships of inhibitors of steroid aromatase which catalyses the last stage of a multistep biotransformation of cholesterol into estrogens, viz., aromatisation of C19-steroids into C18-phenolic steroids, are discussed. Compounds of the androstane series which are structurally related to the natural substrate, viz., androst-4-ene-3,17-dione, are the subjects of consideration. The review encompasses problems of synthesis of various substituted androstanes and their aromatase-inhibiting activities and structural requirements for selective specific aromatase inhibitors based on in vitro and in vivo structure-activity studies of compounds synthesised, their biological properties and the results of clinical trials. Special attention is paid to practical applications of aromatase inhibitors in the treatment of hormone-dependent mammary and ovarian tumours as well as benign prostatic tumours. In writing this report, the author has used all the information currently available in the chemical, biochemical, endocrinological and medicinal literature as well as in patents. The bibliography includes 173 references.

  13. Carbonic anhydrase inhibitors drug design.

    PubMed

    McKenna, Robert; Supuran, Claudiu T

    2014-01-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported.

  14. Thioredoxin Reductase and its Inhibitors

    PubMed Central

    Saccoccia, Fulvio; Angelucci, Francesco; Boumis, Giovanna; Carotti, Daniela; Desiato, Gianni; Miele, Adriana E; Bellelli, Andrea

    2014-01-01

    Thioredoxin plays a crucial role in a wide number of physiological processes, which span from reduction of nucleotides to deoxyriboucleotides to the detoxification from xenobiotics, oxidants and radicals. The redox function of Thioredoxin is critically dependent on the enzyme Thioredoxin NADPH Reductase (TrxR). In view of its indirect involvement in the above mentioned physio/pathological processes, inhibition of TrxR is an important clinical goal. As a general rule, the affinities and mechanisms of binding of TrxR inhibitors to the target enzyme are known with scarce precision and conflicting results abound in the literature. A relevant analysis of published results as well as the experimental procedures is therefore needed, also in view of the critical interest of TrxR inhibitors. We review the inhibitors of TrxR and related flavoreductases and the classical treatment of reversible, competitive, non competitive and uncompetitive inhibition with respect to TrxR, and in some cases we are able to reconcile contradictory results generated by oversimplified data analysis. PMID:24875642

  15. Aromatase Inhibitors and Other Compounds for Lowering Breast Cancer Risk

    MedlinePlus

    ... Cancer Risk and Prevention Aromatase Inhibitors for Lowering Breast Cancer Risk Aromatase inhibitors (drugs that lower estrogen levels) ... day. Can aromatase inhibitors lower the risk of breast cancer? Aromatase inhibitors are used mainly to treat hormone ...

  16. Inhibitors

    MedlinePlus

    ... mortality in the United States. American Journal of Hematology. 2015; 90:400-405. Miller CH, Benson J, ... A: rationale and latest evidence. Therapeutic Advances in Hematology. 2013; 4(1):59-72. Hay CR, DiMichele ...

  17. Complexes of a Zn-metalloenzyme binding site with hydroxamate-containing ligands. A case for detailed benchmarkings of polarizable molecular mechanics/dynamics potentials when the experimental binding structure is unknown.

    PubMed

    Gresh, Nohad; Perahia, David; de Courcy, Benoit; Foret, Johanna; Roux, Céline; El-Khoury, Lea; Piquemal, Jean-Philip; Salmon, Laurent

    2016-12-15

    Zn-metalloproteins are a major class of targets for drug design. They constitute a demanding testing ground for polarizable molecular mechanics/dynamics aimed at extending the realm of quantum chemistry (QC) to very long-duration molecular dynamics (MD). The reliability of such procedures needs to be demonstrated upon comparing the relative stabilities of competing candidate complexes of inhibitors with the recognition site stabilized in the course of MD. This could be necessary when no information is available regarding the experimental structure of the inhibitor-protein complex. Thus, this study bears on the phosphomannose isomerase (PMI) enzyme, considered as a potential therapeutic target for the treatment of several bacterial and parasitic diseases. We consider its complexes with 5-phospho-d-arabinonohydroxamate and three analog ligands differing by the number and location of their hydroxyl groups. We evaluate the energy accuracy expectable from a polarizable molecular mechanics procedure, SIBFA. This is done by comparisons with ab initio quantum-chemistry (QC) calculations in the following cases: (a) the complexes of the four ligands in three distinct structures extracted from the entire PMI-ligand energy-minimized structures, and totaling up to 264 atoms; (b) the solvation energies of several energy-minimized complexes of each ligand with a shell of 64 water molecules; (c) the conformational energy differences of each ligand in different conformations characterized in the course of energy-minimizations; and (d) the continuum solvation energies of the ligands in different conformations. The agreements with the QC results appear convincing. On these bases, we discuss the prospects of applying the procedure to ligand-macromolecule recognition problems. © 2016 Wiley Periodicals, Inc.

  18. Bisindole-PBD regulates breast cancer cell proliferation via SIRT-p53 axis.

    PubMed

    Sarma, Pranjal; Bag, Indira; Ramaiah, M Janaki; Kamal, Ahmed; Bhadra, Utpal; Pal Bhadra, Manika

    2015-01-01

    In a previous study we reported the role of potent bisindole-PBD conjugate as an inclusion in the arsenal of breast cancer therapeutics. In breast cancer cell proliferation, PI3K/AKT/mTOR pathway plays a crucial role by prosurvival mechanism that inhibits programmed cell death. Here, 2 breast cancer cells lines, MCF-7 and MDA-MB-231 were treated with Vorinostat (suberoylanilide hydroxamic acid / SAHA) and bisindole-PBD (5b). We have investigated the effect on PI3K/AKT/mTOR pathway and SIRT expression including epigenetic regulation. There was consistent decrease in the level of PI3K, AKT, mTOR proteins upon treatment of 5b in both MCF-7 and MDA-MB-231 cell lines compared to untreated controls. Treatment with caspase inhibitor (Q-VD-OPH) confirmed that the effect of 5b on PI3K signaling was ahead of apoptosis. Real time PCR and western blot analysis showed profound reduction in the mRNA and protein levels of SIRT1 and SIRT2. Molecular docking studies also supported the interaction of 5b with various amino acids of SIRT2 proteins. Treatment with 5b caused epigenetic changes that include increase of acetylated forms of p53, increase of histone acetylation at p21 promoter as well as decrease in methylation state of p21 gene. Compound 5b thus acts as SIRT inhibitor and cause p53 activation via inhibition of growth factor signaling and activation of p53 dependent apoptotic signaling. This present study focuses bisindole-PBD on epigenetic alteration putting 5b as a promising therapeutic tool in the realm of breast cancer research.

  19. Histone deacetylase inhibition blunts ischemia/reperfusion injury by inducing cardiomyocyte autophagy.

    PubMed

    Xie, Min; Kong, Yongli; Tan, Wei; May, Herman; Battiprolu, Pavan K; Pedrozo, Zully; Wang, Zhao V; 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

    2014-03-11

    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 suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor approved for cancer treatment by the US Food and Drug Administration, will blunt reperfusion injury. Twenty-one rabbits were randomly assigned to 3 groups: (1) vehicle control, (2) SAHA pretreatment (1 day before and at surgery), and (3) SAHA treatment at the time of reperfusion only. Each arm was subjected to ischemia/reperfusion surgery (30 minutes coronary ligation, 24 hours reperfusion). In addition, cultured neonatal and adult rat ventricular cardiomyocytes were subjected to simulated ischemia/reperfusion to probe mechanism. SAHA reduced infarct size and partially rescued systolic function when administered either before surgery (pretreatment) or solely at the time of reperfusion. SAHA plasma concentrations were similar to those achieved in patients with cancer. In the infarct border zone, SAHA increased autophagic flux, assayed in both rabbit myocardium and in mice harboring an RFP-GFP-LC3 transgene. In cultured myocytes subjected to simulated ischemia/reperfusion, SAHA pretreatment reduced cell death by 40%. This reduction 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. The US Food and Drug Administration-approved anticancer histone deacetylase 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 ischemia/reperfusion occur, at least in part, through the induction of autophagic flux.

  20. Early prediction of response to Vorinostat in an orthotopic glioma rat model

    PubMed Central

    Wei, Li; Hong, Samuel; Yoon, Younghyoun; Hwang, Scott N.; Park, Jaekeun C.; Zhang, Zhaobin; Olson, Jeffrey J.; Hu, Xiaoping P.; Shim, Hyunsuk

    2012-01-01

    Glioblastoma (GBM) is the most common primary brain tumor and is uniformly fatal despite aggressive surgical and adjuvant therapy. Since survival is short, it is critical to determine the value of therapy early on in treatment. Improved early predictive assessment would allow neuro-oncologists to personalize and adjust or change treatment sooner to maximize use of efficacious therapy. During carcinogenesis, tumor suppressor genes can be silenced by aberrant histone deacetylation. This epigenetic modification has become an important target for tumor therapy. Suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza; Merck & Co., Inc.) is an orally active, potent inhibitor of histone deacetylase (HDAC) activity. A major shortcoming of the use of HDAC inhibitors in treating brain tumor patients is the lack of reliable biomarkers to predict and determine response. Histological evaluation may reflect tumor viability following treatment but it is an invasive procedure and impractical for GBM. Another problem is that response to SAHA therapy is associated with tumor redifferentiation and cytostasis rather than tumor size reduction, thus limiting the use of traditional imaging methods. A noninvasive method to assess drug delivery and efficacy is needed. Here, we investigated whether changes in 1H MRS metabolites could render reliable biomarkers for an early response to SAHA treatment in an orthotopic animal model for glioma. Untreated tumors exhibited significantly elevated alanine and lactate levels and reduced inositol, NAA and creatine, typical changes reported in GBM compared to normal brain tissues. The proton MRS-detectable metabolites of SAHA treated tumors were restored toward those of normal-like brain tissues. In addition, reduced inositol and NAA were found to be potential biomarkers for mood alteration and depression, which may also be alleviated with SAHA treatment. Our study suggests that 1H MRS can provide reliable metabolic biomarkers at the earliest stage

  1. Bromodomain and extra-terminal (BET) bromodomain inhibition activate transcription via transient release of positive transcription elongation factor b (P-TEFb) from 7SK small nuclear ribonucleoprotein.

    PubMed

    Bartholomeeusen, Koen; Xiang, Yanhui; Fujinaga, Koh; Peterlin, B Matija

    2012-10-19

    By phosphorylating elongation factors and the C-terminal domain of RNA polymerase II, the positive transcription elongation factor b (P-TEFb) is the critical kinase for transcription elongation and co-transcriptional processing of eukaryotic genes. It exists in inactive small nuclear ribonucleoprotein (7SK snRNP) and active (free P-TEFb) complexes in cells. The P-TEFb equilibrium determines the state of cellular activation, proliferation, and differentiation. Free P-TEFb, which is required for growth, can be recruited to RNA polymerase II via transcription factors, BRD4, or the super elongation complex (SEC). UV light, various signaling cascades, transcriptional blockade, or compounds such as hexamethylene bisacetamide (HMBA), suberoylanilide hydroxamic acid (SAHA), and other histone deacetylase inhibitors lead to a rapid release of free P-TEFb, followed by its reassembly into the 7SK snRNP. As a consequence, transcription of HEXIM1, a critical 7SK snRNP subunit, and HIV is induced. In this study, we found that a bromodomain and extra-terminal (BET) bromodomain inhibitor, JQ1, which inhibits BRD4 by blocking its association with chromatin, also leads to the rapid release of free P-TEFb from the 7SK snRNP. Indeed, JQ1 transiently increased levels of free P-TEFb and BRD4·P-TEFb and SEC·P-TEFb complexes in cells. As a consequence, the levels of HEXIM1 and HIV proteins rose. Importantly, the knockdown of ELL2, a subunit of the SEC, blocked the ability of JQ1 to increase HIV transcription. Finally, the effects of JQ1 and HMBA or SAHA on the P-TEFb equilibrium were cooperative. We conclude that HMBA, SAHA, and JQ1 affect transcription elongation by a similar and convergent mechanism.

  2. Combined treatment with SAHA, bortezomib, and clarithromycin for concomitant targeting of aggresome formation and intracellular proteolytic pathways enhances ER stress-mediated cell death in breast cancer cells.

    PubMed

    Komatsu, Seiichiro; Moriya, Shota; Che, Xiao-Fang; Yokoyama, Tomohisa; Kohno, Norio; Miyazawa, Keisuke

    2013-07-19

    The ubiquitin-proteasome pathway and the autophagy-lysosome pathway are two major intracellular protein degradation systems. We previously reported that clarithromycin (CAM) blocks autophagy flux, and that combined treatment with CAM and proteasome inhibitor bortezomib (BZ) enhances ER-stress-mediated apoptosis in breast cancer cells, whereas treatment with CAM alone results in almost no cytotoxicity. Since HDAC6 is involved in aggresome formation, which is recognized as a cytoprotective response serving to sequester misfolded proteins and facilitate their clearance by autophagy, we further investigated the combined effect of vorinostat (suberoylanilide hydroxamic acid (SAHA)), which has a potent inhibitory effect for HDAC6, with CAM and BZ in breast cancer cell lines. SAHA exhibited some cytotoxicity along with an increased acetylation level of α-tubulin, a substrate of HDAC6. Combined treatment of SAHA, CAM, and BZ potently enhanced the apoptosis-inducing effect compared with treatment using each reagent alone or a combination of two of the three. Expression levels of ER-stress-related genes, including the pro-apoptotic transcription factor CHOP (GADD153), were maximally induced by the simultaneous combination of three reagents. Like breast cancer cell lines, a wild-type murine embryonic fibroblast (MEF) cell line exhibited enhanced cytotoxicity and maximally up-regulated Chop after combined treatment with SAHA, CAM, and BZ; however, a Chop knockout MEF cell line almost completely canceled this enhanced effect. The specific HDAC6 inhibitor tubacin also exhibited a pronounced cytocidal effect with a combination of CAM plus BZ. These data suggest that simultaneous targeting of intracellular proteolytic pathways and HDAC6 enhances ER-stress-mediated apoptosis in breast cancer cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Epigenetic status determines germ cell meiotic commitment in embryonic and postnatal mammalian gonads.

    PubMed

    Wang, Ning; Tilly, Jonathan L

    2010-01-15

    The meiotic cell cycle is required for production of fertilization-competent gametes. Germ cell meiotic commitment requires expression of Stimulated by retinoic acid gene 8 (Stra8), which is transcriptionally activated by retinoic acid (RA). Meiotic suppression in embryonic male germ cells is believed to result from sex-specific differences in CYP26B1-catalyzed RA metabolism in the developing gonads. Here we show in mice that RA-induced Stra8 transcription is epigenetically controlled and requires a co-activator that binds proximal to the RA response elements (RAREs) in the Stra8 promoter. Embryonic male germ cells exposed in utero to the class I/II histone deacetylase (HDAC) inhibitor, trichostatin-A (TSA), show premature Stra8 activation and meiotic entry without altered Cyp26b1 expression. We also show that Stra8 expression is detectable and physiologically regulated in adult mouse ovaries. Further, oogenesis induction in adult females using TSA is associated with Stra8 activation, and these events are absent in mice deficient in the RA precursor vitamin A. Finally, all of the actions of TSA in premeiotic germ cells in vitro and in mouse ovaries in vivo can be reproduced with the small molecule HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA). Thus, the ability of RA to transcriptionally induce expression of the meiosis-commitment gene, Stra8, is epigenetically controlled and this process involves a novel co-activator that functions upstream of the RAREs. These events not only coordinate the sex-specific timing of meiotic entry during embryogenesis, but also contribute to the regulation of oogenesis in adult female mammals.

  4. Epigenetic status determines germ cell meiotic commitment in embryonic and postnatal mammalian gonads

    PubMed Central

    Wang, Ning; Tilly, Jonathan L.

    2017-01-01

    The meiotic cell cycle is required for production of fertilization-competent gametes. Germ cell meiotic commitment requires expression of Stimulated by retinoic acid gene 8 (Stra8), which is transcriptionally activated by retinoic acid (RA). Meiotic suppression in embryonic male germ cells is believed to result from sex-specific differences in CYP26B1-catalyzed RA metabolism in the developing gonads. Here we show in mice that RA-induced Stra8 transcription is epigenetically controlled and requires a co-activator that binds proximal to the RA response elements (RAREs) in the Stra8 promoter. Embryonic male germ cells exposed in utero to the class I/II histone deacetylase (HDAC) inhibitor, trichostatin-A (TSA), show premature Stra8 activation and meiotic entry without altered Cyp26bl expression. We also show that Stra8 expression is detectable and physiologically regulated in adult mouse ovaries. Further, oogenesis induction in adult females using TSA is associated with Stra8 activation, and these events are absent in mice deficient in the RA precursor vitamin A. Finally, all of the actions of TSA in premeiotic germ cells in vitro and in mouse ovaries in vivo can be reproduced with the small molecule HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA). Thus, the ability of RA to transcriptionally induce expression of the meiosis-commitment gene, Stra8, is epigenetically controlled and this process involves a novel co-activator that functions upstream of the RAREs. These events not only coordinate the sex-specific timing of meiotic entry during embryogenesis, but also contribute to the regulation of oogenesis in adult female mammals. PMID:20009537

  5. MMP Inhibitors on Dentin Stability

    PubMed Central

    Montagner, A.F.; Sarkis-Onofre, R.; Pereira-Cenci, T.; Cenci, M.S.

    2014-01-01

    The aim of this study was to systematically review the literature for in vitro and ex vivo studies that evaluated the effect of matrix metalloproteinase (MMP) inhibitors during the adhesive procedure on the immediate and long-term resin-dentin bond strength. The search was conducted in 6 databases with no publication year or language limits, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From 1,336 potentially eligible studies, 48 were selected for full-text analysis, and 30 were included for review, with 17 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Pooled effect estimates were expressed as the weighted mean difference between groups. The most used MMP inhibitor was chlorhexidine (CHX). Immediate bond strength results showed no difference between 2% CHX and control; however, a difference was found between 0.2% CHX and control at baseline. After aging, CHX presented higher bond strength values compared to control groups (p < .05). However, this was not observed for longer periods of aging. High heterogeneity was found in some comparisons, especially for the water storage aging subgroup. Subgroup analyses showed that self-etching and etch-and-rinse adhesives are benefited by the CHX use. From the studies included, only 1 presented low risk of bias, while the others showed medium or high risk of bias. The use of MMP inhibitors did not affect the immediate bond strength overall, while it influenced the aged bond strength. Aging procedures influenced bond strength values of the dentin adhesion stability. PMID:24935066

  6. Monoamine Oxidase Inhibitors: Clinical Review

    PubMed Central

    Remick, Ronald A.; Froese, Colleen

    1990-01-01

    Monoamine oxidase inhibitors (MAOIs) are effective antidepressant agents. They are increasingly and effectively used in a number of other psychiatric and non-psychiatric medical syndromes. Their potential for serious toxicity (i.e., hypertensive reaction) is far less than original reports suggest, and newer reversible substrate-specific MAOIs may offer even less toxicity. The author reviews the pharmacology, mechanism of action, clinical indications, and dosing strategies of MAOIs. The common MAOI side-effects (hypotension, weight gain, sexual dysfunction, insomnia, daytime sedation, myoclonus, and hypertensive episodes) are described and management techniques suggested. Recent clinical developments involving MAOIs are outlined. PMID:21233984

  7. Techniques for Screening Translation Inhibitors

    PubMed Central

    Osterman, Ilya A.; Bogdanov, Alexey A.; Dontsova, Olga A.; Sergiev, Petr V.

    2016-01-01

    The machinery of translation is one of the most common targets of antibiotics. The development and screening of new antibiotics usually proceeds by testing antimicrobial activity followed by laborious studies of the mechanism of action. High-throughput methods for new antibiotic screening based on antimicrobial activity have become routine; however, identification of molecular targets is usually a challenge. Therefore, it is highly beneficial to combine primary screening with the identification of the mechanism of action. In this review, we describe a collection of methods for screening translation inhibitors, with a special emphasis on methods which can be performed in a high-throughput manner. PMID:27348012

  8. Angiogenesis Inhibitors in Breast Cancer

    DTIC Science & Technology

    2005-04-01

    Westling et al., 2002). 3) Cleavage of TSP-I is not shared by ADAMTS-4. ADAMTS-1 and ADAMTS-4 display high sequence homology and more importantly, both...Manzaneque JC, Westling J, Thai SN, Luque A, Knauper V, Murphy G, Sandy JD, Iruela-Arispe ML. ADAMTS1 cleaves aggrecan at multiple sites and is...differentially inhibited by metalloproteinase inhibitors. Biochem Biophys Res Commun. 2002 Apr 26;293(1):501-8. * Sandy JD, Westling J, Kenagy RD, Iruela-Arispe

  9. Natural products as aromatase inhibitors.

    PubMed

    Balunas, Marcy J; Su, Bin; Brueggemeier, Robert W; Kinghorn, A Douglas

    2008-08-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purposes (e.g., botanical dietary supplements) may also afford AIs with reduced side effects. A thorough review of the literature regarding natural product extracts and secondary metabolites of plant, microbial, and marine origin that have been shown to exhibit aromatase inhibitory activity is presented herein.

  10. Techniques for Screening Translation Inhibitors.

    PubMed

    Osterman, Ilya A; Bogdanov, Alexey A; Dontsova, Olga A; Sergiev, Petr V

    2016-06-24

    The machinery of translation is one of the most common targets of antibiotics. The development and screening of new antibiotics usually proceeds by testing antimicrobial activity followed by laborious studies of the mechanism of action. High-throughput methods for new antibiotic screening based on antimicrobial activity have become routine; however, identification of molecular targets is usually a challenge. Therefore, it is highly beneficial to combine primary screening with the identification of the mechanism of action. In this review, we describe a collection of methods for screening translation inhibitors, with a special emphasis on methods which can be performed in a high-throughput manner.

  11. Dual Action of Respiratory Inhibitors

    PubMed Central

    Khan, Anwar A.; Zeng, Guang-Wen

    1985-01-01

    `Grand Rapids' lettuce Lactuca sativa L. seeds germinate readily at 15°C but poorly at 25°C in darkness. When held in dark at 25°C for an extended period, the ungerminated seeds become dormant as shown by their inability to germinate or transfer to 15°C in darkness. Induction of dormancy at 25°C was prevented by exposure to CN−, azide, s