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Sample records for selective faah inhibitor

  1. Metabolism and disposition of MM-433593, a selective FAAH-1 inhibitor, in monkeys

    PubMed Central

    Banijamali, Ali R; Wakefield, James D; Mermerian, Ara H; Busby, Robert W

    2014-01-01

    MM-433593 is a highly potent and selective inhibitor of fatty acid amide hydrolase-1 (FAAH-1) with potential utility as an orally administered treatment of pain, inflammation, and other disorders. In this study, we investigated the metabolism and pharmacokinetics of MM-433593 in monkeys, and compared plasma and urine metabolites of this compound to the in vitro metabolites produced by monkey hepatocytes. Intravenous administration of MM-433593 to cynomolgus monkeys produced a rapid distribution phase and slower elimination phase with a mean systemic clearance rate of 8–11 mL/min/kg. Absolute oral bioavailability was determined to be 14–21% with maximum plasma concentrations reached ∼3 h (Tmax) following a 10 mg/kg oral dose. The average terminal half-life of MM-433593 was 17–20 h, and there were no qualitative sex differences in the metabolite profile of MM-433593. The major site of metabolism was oxidation of the methyl group at the five position of the indole ring, which was confirmed by chromatography and mass spectrometry comparison to a synthesized authentic standard. This metabolite was further oxidized to the corresponding carboxylic acid and/or conjugated with sulfate, glucuronide, or glutathione. In all, 18 metabolites were found in plasma and urine. In vitro incubations of MM-433593 with monkey hepatocytes yielded 13 metabolites, all of which were found in vivo, indicating a good correlation between the in vitro and in vivo metabolism data. A comprehensive pathway for the metabolism of MM-433593 is proposed, including a plausible, five-step biotransformation for the formation of N-acetylcysteine conjugate metabolite (M18) from the hydroxylated parent (M5). PMID:25505606

  2. FAAH inhibitors in the limelight, but regrettably

    PubMed Central

    Mallet, Christophe; Dubray, Claude; Dualé, Christian

    2016-01-01

    Abstract. This short review focuses on the recent drug development of FAAH inhibitors, as recent serious adverse events have been reported in a phase I study with a compound of this class. The authors overview the potential interest in targeting FAAH inhibition, the current programs, and the available information on the recent dramatic events. PMID:27191771

  3. Pyrazole phenylcyclohexylcarbamates as inhibitors of human fatty acid amide hydrolases (FAAH).

    PubMed

    Aghazadeh Tabrizi, Mojgan; Baraldi, Pier Giovanni; Ruggiero, Emanuela; Saponaro, Giulia; Baraldi, Stefania; Romagnoli, Romeo; Martinelli, Adriano; Tuccinardi, Tiziano

    2015-06-01

    Fatty acid amide hydrolase (FAAH) inhibitors have gained attention as potential therapeutic targets in the management of neuropathic pain. Here, we report a series of pyrazole phenylcyclohexylcarbamate derivatives standing on the known carbamoyl FAAH inhibitor URB597. Structural modifications led to the recognition of compound 22 that inhibited human recombinant FAAH (hrFAAH) in the low nanomolar range (IC50 = 11 nM). The most active compounds of this series showed significant selectivity toward monoacylglycerol lipase (MAGL) enzyme. In addition, molecular modeling and reversibility behavior of the new class of FAAH inhibitors are presented in this article. PMID:26002335

  4. Systemic and spinal administration of FAAH, MAGL inhibitors and dual FAAH/MAGL inhibitors produce antipruritic effect in mice.

    PubMed

    Yesilyurt, Ozgur; Cayirli, Mutlu; Sakin, Yusuf Serdar; Seyrek, Melik; Akar, Ahmet; Dogrul, Ahmet

    2016-07-01

    The increase of endocannabinoid tonus by inhibiting fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL) represents a promising therapeutic approach in a variety of disease to overcome serious central side effects of exocannabinoids. Recent studies reported that systemic administration of FAAH and MAGL inhibitors produce antipruritic action. Dual FAAH/MAGL inhibitors have also been described to get enhanced endocannabinoid therapeutic effect. In this study, we examined and compared dose-related antipruritic effects of systemic (intraperitoneal; ip) or intrathecal (it) administration of selective FAAH inhibitor PF-3845 (5, 10, and 20 mg/kg, i.p.; 1, 5, and 10 µg, i.t.), MAGL inhibitor JZL184 (4, 20, and 40 mg/kg, i.p.; 1, 5, and 10 µg, i.t.) and dual FAAH/MAGL inhibitor JZL195 (2, 5, and 20 mg/kg, i.p.; 1, 5, and 10 µg, i.t.) on serotonin (5-HT)-induced scratching model. Serotonin (25 μg) was injected intradermally in a volume of 50 μl into the rostral part of skin on the back of male Balb-C mice. Both systemic or intrathecal administration of PF-3845, JZL184 or JZL195 produced similar dose-dependent antipruritic effects. Our results suggest that endocannabinoid-degrading enzymes FAAH and MAGL are involved in pruritic process at spinal level. FAAH, MAGL or dual FAAH/MAGL inhibitors have promising antipruritic effects, at least, in part through spinal site of action. PMID:27126057

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

    PubMed Central

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

    2011-01-01

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

  6. Design, synthesis and biological evaluation of potent FAAH inhibitors.

    PubMed

    Tuo, Wei; Leleu-Chavain, Natascha; Barczyk, Amélie; Renault, Nicolas; Lemaire, Lucas; Chavatte, Philippe; Millet, Régis

    2016-06-01

    A new series of 3-carboxamido-5-aryl-isoxazoles was designed, synthesized and evaluated for their biological activity. Different pharmacomodulations have been explored and the lipophilicity of these compounds was assessed. Investigation of the in vitro biological activity led to the identification of 5 compounds as potent FAAH inhibitors, their good FAAH inhibition capacity is probably correlated with their suitable lipophilicity. Specifically, compound 25 showed similar inhibition potency against FAAH in comparison with URB597, one of the most potent FAAH inhibitor known to date. PMID:27117424

  7. Piperidinyl thiazole isoxazolines: A new series of highly potent, slowly reversible FAAH inhibitors with analgesic properties.

    PubMed

    Pember, Stephen O; Mejia, Galo L; Price, Theodore J; Pasteris, Robert J

    2016-06-15

    Fatty acid amide hydrolase (FAAH) is a membrane anchored serine hydrolase that has a principle role in the metabolism of the endogenous cannabinoid anandamide. Docking studies using representative FAAH crystal structures revealed that compounds containing a novel piperidinyl thiazole isoxazoline core fit within the ligand binding domains. New potential FAAH inhibitors were designed and synthesized incorporating urea, carbamate, alkyldione and thiourea reactive centers as potential pharmacophores. A small library of candidate compounds (75) was then screened against human FAAH leading to the identification of new carbamate and urea based inhibitors (Ki=pM and nM, respectively). Representative carbamate and urea based chemotypes displayed slow, time dependent inhibition kinetics leading to enzyme inactivation which was slowly reversible. However, evidence indicated that features of the mechanism of inactivation differ between the two pharmacophore types. Selected compounds were also evaluated for analgesic activity in the mouse-tail flick test. PMID:27130358

  8. Prostamide F2α receptor antagonism combined with inhibition of FAAH may block the pro-inflammatory mediators formed following selective FAAH inhibition

    PubMed Central

    Ligresti, Alessia; Martos, Jose; Wang, Jenny; Guida, Francesca; Allarà, Marco; Palmieri, Vittoria; Luongo, Livio; Woodward, David; Di Marzo, Vincenzo

    2014-01-01

    Background and PurposeProstamides are lipid mediators formed by COX-2-catalysed oxidation of the endocannabinoid anandamide and eliciting effects often opposed to those caused by anandamide. Prostamides may be formed when hydrolysis of anandamide by fatty acid amide hydrolase (FAAH) is physiologically, pathologically or pharmacologically decreased. Thus, therapeutic benefits of FAAH inhibitors might be attenuated by concomitant production of prostamide F2α. This loss of benefit might be minimized by compounds designed to selectively antagonize prostamide receptors and also inhibiting FAAH. Experimental ApproachInhibition of FAAH by a series of selective antagonists of prostamide receptors, including AGN 204396, AGN 211335 and AGN 211336, was assessed using rat, mouse and human FAAH in vitro, together with affinity for human recombinant CB1 and CB2 receptors. Effects in vivo were measured in a model of formalin-induced inflammatory pain in mice. Key ResultsThe prostamide F2α receptor antagonists were active against mouse and rat FAAH in the low μM range and behaved as non-competitive and plasma membrane-permeant inhibitors. AGN 211335, the most potent inhibitor of rat FAAH (IC50 = 1.2 μM), raised exogenous anandamide levels in intact cells and also bound to cannabinoid CB1 receptors. Both AGN 211335 and AGN 211336 (0.25–1 mg·kg−1, i.p.) inhibited the formalin-induced nociceptive response in mice. Conclusions and ImplicationsSynthetic compounds with indirect agonist activity at cannabinoid receptors and antagonist activity at prostamide receptors can be developed. Such compounds could be used as alternatives to selective FAAH inhibitors to prevent the possibility of prostamide F2α-induced inflammation and pain. Linked ArticlesThis article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-6 PMID:24102214

  9. Correlating FAAH and anandamide cellular uptake inhibition using N-alkylcarbamate inhibitors: from ultrapotent to hyperpotent.

    PubMed

    Nicolussi, Simon; Chicca, Andrea; Rau, Mark; Rihs, Sabine; Soeberdt, Michael; Abels, Christoph; Gertsch, Jürg

    2014-12-15

    Besides the suggested role of a putative endocannabinoid membrane transporter mediating the cellular uptake of the endocannabinoid anandamide (AEA), this process is intrinsically coupled to AEA degradation by the fatty acid amide hydrolase (FAAH). Differential blockage of each mechanism is possible using specific small-molecule inhibitors. Starting from the natural product-derived 2E,4E-dodecadiene scaffold previously shown to interact with the endocannabinoid system (ECS), a series of diverse N-alkylcarbamates were prepared with the aim of generating novel ECS modulators. While being inactive at cannabinoid receptors and monoacylglycerol lipase, these N-alkylcarbamates showed potent to ultrapotent picomolar FAAH inhibition in U937 cells. Overall, a highly significant correlation (Spearman's rho=0.91) was found between the inhibition of FAAH and AEA cellular uptake among 54 compounds. Accordingly, in HMC-1 cells lacking FAAH expression the effect on AEA cellular uptake was dramatically reduced. Unexpectedly, 3-(4,5-dihydrothiazol-2-yl)phenyl carbamates and the 3-(1,2,3-thiadiazol-4-yl)phenyl carbamates WOBE490, WOBE491 and WOBE492 showed a potentiation of cellular AEA uptake inhibition in U937 cells, resulting in unprecedented femtomolar (hyperpotent) IC50 values. Potential methodological issues and the role of cellular accumulation of selected probes were investigated. It is shown that albumin impacts the potency of specific N-alkylcarbamates and, more importantly, that accumulation of FAAH inhibitors can significantly increase their effect on cellular AEA uptake. Taken together, this series of N-alkylcarbamates shows a FAAH-dependent inhibition of cellular AEA uptake, which can be strongly potentiated using specific head group modifications. These findings provide a rational basis for the development of hyperpotent AEA uptake inhibitors mediated by ultrapotent FAAH inhibition. PMID:25283614

  10. Targeting the Endocannabinoid System for Neuroprotection: A 19F-NMR Study of a Selective FAAH Inhibitor Binding with an Anandamide Carrier Protein, HSA

    PubMed Central

    Zhuang, Jianqin; Yang, De-Ping; Tian, Xiaoyu; Nikas, Spyros P.; Sharma, Rishi; Guo, Jason Jianxin; Makriyannis, Alexandros

    2013-01-01

    Fatty acid amide hydrolase (FAAH), the enzyme involved in the inactivation of the endocannabinoid anandamide (AEA), is being considered as a therapeutic target for analgesia and neuroprotection. We have developed a brain permeable FAAH inhibitor, AM5206, which has served as a valuable pharmacological tool to explore neuroprotective effects of this class of compounds. In the present work, we characterized the interactions of AM5206 with a representative AEA carrier protein, human serum albumin (HSA), using 19F nuclear magnetic resonance (NMR) spectroscopy. Our data showed that as a drug carrier, albumin can significantly enhance the solubility of AM5206 in aqueous environment. Through a series of titration and competitive binding experiments, we also identified that AM5206 primarily binds to two distinct sites within HSA. Our results may provide insight into the mechanism of HSA-AM5206 interactions. The findings should also help in the development of suitable formulations of the lipophilic AM5206 and its congeners for their effective delivery to specific target sites in the brain. PMID:24533425

  11. The SAR of brain penetration for a series of heteroaryl urea FAAH inhibitors.

    PubMed

    Keith, John M; Tichenor, Mark S; Apodaca, Richard L; Xiao, Wei; Jones, William M; Seierstad, Mark; Pierce, Joan M; Palmer, James A; Webb, Michael; Karbarz, Mark J; Scott, Brian P; Wilson, Sandy J; Wennerholm, Michelle L; Rizzolio, Michele; Rynberg, Raymond; Chaplan, Sandra R; Breitenbucher, J Guy

    2016-07-01

    The SAR of brain penetration for a series of heteroaryl piperazinyl- and piperadinyl-urea fatty acid amide hydrolase (FAAH) inhibitors is described. Brain/plasma (B/P) ratios ranging from >4:1 to as low as 0.02:1 were obtained through relatively simple structural changes to various regions of the heteroaryl urea scaffold. It was not possible to predict the degree of central nervous system (CNS) penetration from the volumes of distribution (Vd) obtained from pharmacokinetic (PK) experiments as very high Vds did not correlate with high B/P ratios. Similarly, calculated topological polar surface areas (TPSAs) did not consistently correlate with the degree of brain penetration. The lowest B/P ratios were observed for those compounds that were significantly ionized at physiological pH. However, as this class of compounds inhibits the FAAH enzyme through covalent modification, low B/P ratios did not preclude effective central target engagement. PMID:27189675

  12. Experimental colitis in mice is attenuated by changes in the levels of endocannabinoid metabolites induced by selective inhibition of fatty acid amide hydrolase (FAAH)

    PubMed Central

    Sałaga, M; Mokrowiecka, A; Zakrzewski, P K; Cygankiewicz, A; Leishman, E; Sobczak, M; Zatorski, H; Małecka-Panas, E; Kordek, R; Storr, M; Krajewska, W M; Bradshaw, H B; Fichna, J

    2014-01-01

    Background and aims Pharmacological treatment and/or maintenance of remission in inflammatory bowel diseases (IBD) is currently one of the biggest challenge in the field of gastroenterology. Available therapies are mostly limited to overcoming the symptoms, but not the cause of the disease. Recently, the endocannabinoid system has been proposed as a novel target in the treatment of IBD. Here we aimed to assess the anti-inflammatory action of the novel fatty acid amide hydrolase (FAAH) inhibitor PF-3845 and its effect on the endocannabinoid and related lipid metabolism during the course of experimental colitis. Methods We used two models of experimental colitis in mice (TNBS- and DSS-induced) and additionally, we employed LC/MS/MS spectrometry to determine the changes in biolipid levels in the mouse colon during inflammation. Results We showed that the FAAH inhibitor PF-3845 reduced experimental TNBS-induced colitis in mice and its anti-inflammatory action is associated with altering the levels of selected biolipids (arachidonic and oleic acid derivatives, prostaglandins and biolipids containing glycine in the mouse colon). Conclusions We show that FAAH is a promising pharmacological target and the FAAH-dependent biolipids play a major role in colitis. Our results highlight and promote therapeutic strategy based on targeting FAAH-dependent metabolic pathways in order to alleviate intestinal inflammation. PMID:24530133

  13. The macamide N-3-methoxybenzyl-linoleamide is a time-dependent fatty acid amide hydrolase (FAAH) inhibitor.

    PubMed

    Almukadi, Haifa; Wu, Hui; Böhlke, Mark; Kelley, Charles J; Maher, Timothy J; Pino-Figueroa, Alejandro

    2013-10-01

    The Peruvian plant Lepidium meyenii (Maca) has been shown to possess neuroprotective activity both in vitro and in vivo. Previous studies have also demonstrated the activity of the pentane extract and its macamides, the most representative lipophilic constituents of Maca, in the endocannabinoid system as fatty acid amide hydrolase (FAAH) inhibitors. One of the most active macamides, N-3-methoxybenzyl-linoleamide, was studied to determine its mechanism of interaction with FAAH and whether it has inhibitory activity on mono-acyl glycerol lipase (MAGL), the second enzyme responsible for endocannabinoid degradation. Macamide concentrations from 1 to 100 μM were tested using FAAH and MAGL inhibitor assay methods and showed no effect on MAGL. Tests with other conditions were performed in order to characterize the inhibitory mechanism of FAAH inhibition. N-3-methoxybenzyl-linoleamide displayed significant time-dependent and dose-dependent FAAH inhibitory activity. The mechanism of inhibition was most likely irreversible or slowly reversible. These results suggest the potential application of macamides isolated from Maca as FAAH inhibitors, as they might act on the central nervous system to provide analgesic, anti-inflammatory, or neuroprotective effects, by modulating the release of neurotransmitters. PMID:23853040

  14. Effects of Fatty Acid Amide Hydrolase (FAAH) Inhibitors in Non-Human Primate Models of Nicotine Reward and Relapse.

    PubMed

    Justinova, Zuzana; Panlilio, Leigh V; Moreno-Sanz, Guillermo; Redhi, Godfrey H; Auber, Alessia; Secci, Maria E; Mascia, Paola; Bandiera, Tiziano; Armirotti, Andrea; Bertorelli, Rosalia; Chefer, Svetlana I; Barnes, Chanel; Yasar, Sevil; Piomelli, Daniele; Goldberg, Steven R

    2015-08-01

    Inhibition of the enzyme fatty acid amide hydrolase (FAAH) counteracts reward-related effects of nicotine in rats, but it has not been tested for this purpose in non-human primates. Therefore, we studied the effects of the first- and second-generation O-arylcarbamate-based FAAH inhibitors, URB597 (cyclohexyl carbamic acid 3'-carbamoyl-3-yl ester) and URB694 (6-hydroxy-[1,1'-biphenyl]-3-yl-cyclohexylcarbamate), in squirrel monkeys. Both FAAH inhibitors: (1) blocked FAAH activity in brain and liver, increasing levels of endogenous ligands for cannabinoid and α-type peroxisome proliferator-activated (PPAR-α) receptors; (2) shifted nicotine self-administration dose-response functions in a manner consistent with reduced nicotine reward; (3) blocked reinstatement of nicotine seeking induced by reexposure to either nicotine priming or nicotine-associated cues; and (4) had no effect on cocaine or food self-administration. The effects of FAAH inhibition on nicotine self-administration and nicotine priming-induced reinstatement were reversed by the PPAR-α antagonist, MK886. Unlike URB597, which was not self-administered by monkeys in an earlier study, URB694 was self-administered at a moderate rate. URB694 self-administration was blocked by pretreatment with an antagonist for either PPAR-α (MK886) or cannabinoid CB1 receptors (rimonabant). In additional experiments in rats, URB694 was devoid of THC-like or nicotine-like interoceptive effects under drug-discrimination procedures, and neither of the FAAH inhibitors induced dopamine release in the nucleus accumbens shell--consistent with their lack of robust reinforcing effects in monkeys. Overall, both URB597 and URB694 show promise for the initialization and maintenance of smoking cessation because of their ability to block the rewarding effects of nicotine and prevent nicotine priming-induced and cue-induced reinstatement. PMID:25754762

  15. Effects of Fatty Acid Amide Hydrolase (FAAH) Inhibitors in Non-Human Primate Models of Nicotine Reward and Relapse

    PubMed Central

    Justinova, Zuzana; Panlilio, Leigh V; Moreno-Sanz, Guillermo; Redhi, Godfrey H; Auber, Alessia; Secci, Maria E; Mascia, Paola; Bandiera, Tiziano; Armirotti, Andrea; Bertorelli, Rosalia; Chefer, Svetlana I; Barnes, Chanel; Yasar, Sevil; Piomelli, Daniele; Goldberg, Steven R

    2015-01-01

    Inhibition of the enzyme fatty acid amide hydrolase (FAAH) counteracts reward-related effects of nicotine in rats, but it has not been tested for this purpose in non-human primates. Therefore, we studied the effects of the first- and second-generation O-arylcarbamate-based FAAH inhibitors, URB597 (cyclohexyl carbamic acid 3'-carbamoyl-3-yl ester) and URB694 (6-hydroxy-[1,1'-biphenyl]-3-yl-cyclohexylcarbamate), in squirrel monkeys. Both FAAH inhibitors: (1) blocked FAAH activity in brain and liver, increasing levels of endogenous ligands for cannabinoid and α-type peroxisome proliferator-activated (PPAR-α) receptors; (2) shifted nicotine self-administration dose–response functions in a manner consistent with reduced nicotine reward; (3) blocked reinstatement of nicotine seeking induced by reexposure to either nicotine priming or nicotine-associated cues; and (4) had no effect on cocaine or food self-administration. The effects of FAAH inhibition on nicotine self-administration and nicotine priming-induced reinstatement were reversed by the PPAR-α antagonist, MK886. Unlike URB597, which was not self-administered by monkeys in an earlier study, URB694 was self-administered at a moderate rate. URB694 self-administration was blocked by pretreatment with an antagonist for either PPAR-α (MK886) or cannabinoid CB1 receptors (rimonabant). In additional experiments in rats, URB694 was devoid of THC-like or nicotine-like interoceptive effects under drug-discrimination procedures, and neither of the FAAH inhibitors induced dopamine release in the nucleus accumbens shell—consistent with their lack of robust reinforcing effects in monkeys. Overall, both URB597 and URB694 show promise for the initialization and maintenance of smoking cessation because of their ability to block the rewarding effects of nicotine and prevent nicotine priming-induced and cue-induced reinstatement. PMID:25754762

  16. FAAH inhibitor OL-135 disrupts contextual, but not auditory, fear conditioning in rats.

    PubMed

    Burman, Michael A; Szolusha, Kerribeth; Bind, Rebecca; Kerney, Kristen; Boger, Dale L; Bilsky, Edward J

    2016-07-15

    Anxiety disorders are among the most prevalent psychological disorders, have significant negative impacts on quality of life and the healthcare system, and yet effective treatments remain elusive. Manipulating the endocannabinoid system has demonstrated potential for treating anxiety, although the side effects of direct manipulations of cannabinoid receptors keeps them from widespread clinical use. Disrupting the degradation enzyme fatty acid amide hydrolase (FAAH) enhances endogenous signaling and may produce similar efficacy without the side effects. The current experiments examine the effects of low (5.6mg/kg) or moderate (10.0mg/kg) doses of OL-135, a FAAH inhibitor, on the acquisition and consolidation of classical fear conditioning, a common model of trauma-induced anxiety. The acquisition of contextual, but not auditory, fear conditioning was disrupted by both doses of OL-135. Shock reactivity was not affected. Due to the additional neural circuitry required for contextual, but not auditory, fear conditioning, these data suggest that endocannabinoid signaling outside the amygdala may be critical for a subset of fearful memories. PMID:27083303

  17. Identification and characterization of carprofen as a multi-target FAAH/COX inhibitor

    PubMed Central

    Favia, Angelo D.; Habrant, Damien; Scarpelli, Rita; Migliore, Marco; Albani, Clara; Bertozzi, Sine Mandrup; Dionisi, Mauro; Tarozzo, Glauco; Piomelli, Daniele; Cavalli, Andrea; De Vivo, Marco

    2013-01-01

    Pain and inflammation are major therapeutic areas for drug discovery. Current drugs for these pathologies have limited efficacy, however, and often cause a number of unwanted side effects. In the present study, we identify the non-steroid anti-inflammatory drug, carprofen, as a multi-target-directed ligand that simultaneously inhibits cyclooxygenase-1 (COX-1), COX-2 and fatty acid amide hydrolase (FAAH). Additionally, we synthesized and tested several racemic derivatives of carprofen, sharing this multi-target activity. This may result in improved analgesic efficacy and reduced side effects (Naidu, et al (2009) J Pharmacol Exp Ther 329, 48-56; Fowler, C.J. et al. (2012) J Enzym Inhib Med Chem Jan 6; Sasso, et al (2012) Pharmacol Res 65, 553). The new compounds are among the most potent multi-target FAAH/COXs inhibitors reported so far in the literature, and thus may represent promising starting points for the discovery of new analgesic and anti-inflammatory drugs. PMID:23043222

  18. The FAAH inhibitor URB-597 interferes with cisplatin- and nicotine-induced vomiting in the Suncus murinus (house musk shrew)

    PubMed Central

    Parker, LA; Limebeer, CL; Rock, EM; Litt, DL; Kwiatkowska, M.; Piomelli, D.

    2013-01-01

    Considerable evidence implicates the endocannabinoid system as a neuromodulator of nausea and vomiting. The action of anandamide (AEA) can be prolonged by inhibiting its degradation, through the use of URB597 (URB), a Fatty Acid Amide Hydrolase (FAAH) enzyme inhibitor. Here we present evidence that the FAAH inhibitor, URB, interferes with cisplatin- and nicotine -induced vomiting in the Suncus murinus. In Experiment 1, shrews were injected with URB (0.9 mg/kg) or vehicle 120 min prior to the behavioral testing. They received a second injection of AEA (5 mg/kg) or vehicle 15 min prior to being injected with cisplatin (20 mg/kg) or saline and the number of vomiting episodes were counted for 60 min. In Experiment 2, shrews were injected with vehicle or URB (0.9 mg/kg) 120 min prior to receiving an injection of nicotine (5 mg/kg) or saline and the number of vomiting episodes were counted for 15 min. Experiment 3 evaluated the potential of the CB1 antagonist, SR141716, to reverse the effect of URB on nicotine-induced vomiting. URB attenuated vomiting produced by cisplatin and nicotine and the combination of URB+AEA suppressed vomiting produced by cisplatin. The effect of URB on nicotine-induced vomiting was reversed by SR141716. These data suggest that the EC system plays a tonic role in the regulation of toxin-induced vomiting. PMID:19239915

  19. Effects of the Fatty Acid Amide Hydrolase (FAAH) Inhibitor URB597 on Pain-Stimulated and Pain-Depressed Behavior in Rats

    PubMed Central

    Kwilasz, Andrew J.; Abdullah, Rehab A.; Poklis, Justin L.; Lichtman, Aron H.; Negus, S. Stevens

    2014-01-01

    Cannabinoid receptor (CBR) agonists produce antinociception in conventional preclinical assays of pain-stimulated behavior but are not effective in preclinical assays of pain-depressed behavior. Fatty acid amide hydrolase (FAAH) inhibitors increase physiological levels of the endocannabinoid anandamide (AEA), which may confer improved efficacy and/or safety relative to direct CBR agonists. To further evaluate FAAH inhibitors as candidate analgesics, this study assessed effects of the FAAH inhibitor URB597 in assays of acute pain-stimulated and pain-depressed behavior in male Sprague Dawley rats. Intraperitoneal injection of dilute lactic acid served as a noxious stimulus to stimulate a stretching response or depress positively reinforced operant behavior (intracranial self-stimulation; ICSS), and URB597 was tested 1 and 4 h after administration. Consistent with FAAH inhibitor effects in other assays of pain-stimulated behavior, URB597 (1–10 mg/kg IP) produced dose-related and CB1R-mediated decreases in acid-stimulated stretching. Conversely, in the assay of acid-depressed ICSS, URB597 produced a delayed, partial and non-CBR-mediated antinociceptive effect. The antinociceptive dose of URB597 (10 mg/kg) increased plasma and brain AEA levels. These results suggest that URB597 produces antinociception in these models of “pain stimulated” and “pain depressed” behavior, but with different rates of onset and differential involvement of CBRs. PMID:24583930

  20. Structure-property relationships of a class of carbamate-based Fatty Acid Amide Hydrolase (FAAH) inhibitors: chemical and biological stability

    PubMed Central

    Vacondio, Federica; Silva, Claudia; Lodola, Alessio; Fioni, Alessandro; Rivara, Silvia; Duranti, Andrea; Tontini, Andrea; Sanchini, Silvano; Clapper, Jason; Piomelli, Daniele; Tarzia, Giorgio

    2012-01-01

    Cyclohexylcarbamic acid aryl esters are a class of Fatty Acid Amide Hydrolase (FAAH) inhibitors, which includes the reference compound URB597. The reactivity of their carbamate fragment is involved in pharmacological activity and may affect pharmacokinetic and toxicological properties. We conducted in vitro stability experiments in chemical and biological environments to investigate the structure-stability relationships in this class of compounds. The results show that electrophilicity of the carbamate influences its chemical stability, as suggested by the relation between the rate constant of alkaline hydrolysis (log kpH9) and the energy of lowest unoccupied molecular orbital (LUMO). Introduction of small, electron donor substituents at conjugated positions of the O-aryl moiety increased overall hydrolytic stability of the carbamate group without affecting FAAH inhibitory potency, whereas peripheral nonconjugated hydrophilic groups, which favor FAAH recognition, helped reducing oxidative metabolism in the liver. PMID:19554599

  1. Structural determinants of peripheral O-arylcarbamate FAAH inhibitors render them dual substrates for Abcb1 and Abcg2 and restrict their access to the brain

    PubMed Central

    Moreno-Sanz, Guillermo; Barrera, Borja; Armirotti, Andrea; Bertozzi, Sine M.; Scarpelli, Rita; Bandiera, Tiziano; Prieto, Julio G.; Duranti, Andrea; Tarzia, Giorgio; Merino, Gracia

    2014-01-01

    The blood-brain barrier (BBB) is the main entry route for chemicals into the mammalian central nervous system (CNS). Two transmembrane transporters of the ATP-binding cassette (ABC) family – Breast Cancer Resistance Protein (ABCG2 in humans, Abcg2 in rodents) and P-glycoprotein (ABCB1 in humans, Abcb1 in rodents) – play a key role in mediating this process. Pharmacological and genetic evidence suggests that Abcg2 prevents CNS access to a group of highly potent and selective O-arylcarbamate fatty-acid amidohydrolase (FAAH) inhibitors, which include the compound URB937 (cyclohexylcarbamic acid 3′-carbamoyl-6-hydroxybiphenyl-3-yl ester). To define structure-activity relationships of the interaction of these molecules with Abcg2, in the present study we tested various peripherally restricted and non-restricted O-arylcarbamate FAAH inhibitors for their ability to serve as transport substrates in monolayer cultures of Madin-Darby Canine Kidney-II (MDCKII) cells over-expressing Abcg2. Surprisingly, we found that the majority of compounds tested – even those able to enter the CNS in vivo – were substrates for Abcg2 in vitro. Additional experiments in MDCKII cells overexpressing ABCB1 revealed that only those compounds that were dual substrates for ABCB1 and Abcg2 in vitro were also peripherally restricted in vivo. The extent of such restriction seems to depend upon other physicochemical features of the compounds, in particular the polar surface area. Consistent with these in vitro results, we found that URB937 readily enters the brain in dual knockout mice lacking both Abcg2 and Abcb1, whereas it is either partially or completely excluded from the brain of mice lacking either transporter alone. The results suggest that Abcg2 and Abcb1 act together to restrict the access of URB937 to the CNS. PMID:24993496

  2. Crosstalk between liver antioxidant and the endocannabinoid systems after chronic administration of the FAAH inhibitor, URB597, to hypertensive rats.

    PubMed

    Biernacki, Michał; Łuczaj, Wojciech; Gęgotek, Agnieszka; Toczek, Marek; Bielawska, Katarzyna; Skrzydlewska, Elżbieta

    2016-06-15

    Hypertension is accompanied by perturbations to the endocannabinoid and antioxidant systems. Thus, potential pharmacological treatments for hypertension should be examined as modulators of these two metabolic systems. The aim of this study was to evaluate the effects of chronic administration of the fatty acid amide hydrolase (FAAH) inhibitor [3-(3-carbamoylphenyl)phenyl]N-cyclohexylcarbamate (URB597) on the endocannabinoid system and on the redox balance in the livers of DOCA-salt hypertensive rats. Hypertension caused an increase in the levels of endocannabinoids [anandamide (AEA), 2-arachidonoyl-glycerol (2-AG) and N-arachidonoyl-dopamine (NADA)] and CB1 receptor and the activities of FAAH and monoacylglycerol lipase (MAGL). These effects were accompanied by an increase in the level of reactive oxygen species (ROS), a decrease in antioxidant activity/level, enhanced expression of transcription factor Nrf2 and changes to Nrf2 activators and inhibitors. Moreover, significant increases in lipid, DNA and protein oxidative modifications, which led to enhanced levels of proapoptotic caspases, were also observed. URB597 administration to the hypertensive rats resulted in additional increases in the levels of AEA, NADA and the CB1 receptor, as well as decreases in vitamin E and C levels, glutathione peroxidase and glutathione reductase activities and Nrf2 expression. Thus, after URB597 administration, oxidative modifications of cellular components were increased, while the inflammatory response was reduced. This study revealed that chronic treatment of hypertensive rats with URB597 disrupts the endocannabinoid system, which causes an imbalance in redox status. This imbalance increases the levels of electrophilic lipid peroxidation products, which later participate in metabolic disturbances in liver homeostasis. PMID:27086176

  3. Interaction of the N-(3-Methylpyridin-2-yl)amide Derivatives of Flurbiprofen and Ibuprofen with FAAH: Enantiomeric Selectivity and Binding Mode

    PubMed Central

    Deplano, Alessandro; Smaldone, Giovanni; Pedone, Emilia; Luque, F. Javier; Svensson, Mona; Novellino, Ettore; Congiu, Cenzo; Onnis, Valentina; Catalanotti, Bruno; Fowler, Christopher J.

    2015-01-01

    Background Combined fatty acid amide hydrolase (FAAH) and cyclooxygenase (COX) inhibition is a promising approach for pain-relief. The Flu-AM1 and Ibu-AM5 derivatives of flurbiprofen and ibuprofen retain similar COX-inhibitory properties and are more potent inhibitors of FAAH than the parent compounds. However, little is known as to the nature of their interaction with FAAH, or to the importance of their chirality. This has been explored here. Methodology/Principal Findings FAAH inhibitory activity was measured in rat brain homogenates and in lysates expressing either wild-type or FAAHT488A-mutated enzyme. Molecular modelling was undertaken using both docking and molecular dynamics. The (R)- and (S)-enantiomers of Flu-AM1 inhibited rat FAAH with similar potencies (IC50 values of 0.74 and 0.99 μM, respectively), whereas the (S)-enantiomer of Ibu-AM5 (IC50 0.59 μM) was more potent than the (R)-enantiomer (IC50 5.7 μM). Multiple inhibition experiments indicated that both (R)-Flu-AM1 and (S)-Ibu-AM5 inhibited FAAH in a manner mutually exclusive to carprofen. Computational studies indicated that the binding site for the Flu-AM1 and Ibu-AM5 enantiomers was located between the acyl chain binding channel and the membrane access channel, in a site overlapping the carprofen binding site, and showed a binding mode in line with that proposed for carprofen and other non-covalent ligands. The potency of (R)-Flu-AM1 was lower towards lysates expressing FAAH mutated at the proposed carprofen binding area than in lysates expressing wild-type FAAH. Conclusions/Significance The study provides kinetic and structural evidence that the enantiomers of Flu-AM1 and Ibu-AM5 bind in the substrate channel of FAAH. This information will be useful in aiding the design of novel dual-action FAAH: COX inhibitors. PMID:26565710

  4. Just add water: cannabinoid discrimination in a water T-maze with FAAH(-/-) and FAAH(+/+) mice.

    PubMed

    Wiley, Jenny L; Lefever, Timothy W; Pulley, Nikita S; Marusich, Julie A; Cravatt, Benjamin F; Lichtman, Aron H

    2016-08-01

    Incomplete overlap in the discriminative stimulus effects of Δ-tetrahydrocannabinol (THC) and the endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol has been reported in food-reinforced tasks. The aim of this study was to examine cannabinoid discriminative stimulus effects in a nonappetitive procedure. Adult male mice lacking the gene for AEA's major metabolic enzyme, fatty acid amide hydrolase (FAAH), and FAAH mice were trained to discriminate THC or AEA in a water T-maze, in which the response was swimming to an escape platform on the injection-appropriate side. JZL184, a monoacylglycerol lipase inhibitor, was also tested. FAAH mice showed faster acquisition than FAAH mice. THC and AEA fully substituted, with only minor cross-procedure potency variations. Incomplete substitution of JZL184 was observed in THC-trained FAAH mice in the water-maze task, as contrasted with full substitution in a food-reinforced nose-poke procedure. Stress-induced changes in AEA and/or 2-arachidonoylglycerol concentrations in the brain may have mediated this attenuation. JZL184 also partially substituted in AEA-trained FAAH mice in the water maze, suggesting incomplete overlap in the stimulus effects of AEA and JZL184. Through the use of a novel water-maze procedure, the present study supports the work of previous behavioral pharmacologists in showing the robustness of the discrimination paradigm. PMID:27385208

  5. The effects of anandamide signaling enhanced by the FAAH inhibitor URB597 on coping styles in rats

    PubMed Central

    Haller, Jozsef; Goldberg, Steven R.; Pelczer, Katalin Gyimesine; Aliczki, Mano; Panlilio, Leigh V.

    2013-01-01

    Rationale Coping styles are fundamental characteristics of behavior that affect susceptibility to, and resilience during, mental and physical illness. Shifts from passive to active coping are considered therapeutic goals in many stress-related disorders, but the neural control of coping is poorly understood. Based on earlier findings we hypothesized that coping styles are influenced by endocannabinoids. Objectives Here we tested whether FAAH inhibition by URB597 affects behaviors aimed at controlling a critical situation and the degree to which environmental stimuli influence behavior i.e. we studied the impact of URB597 on the two main attributes of coping styles. Methods Rats were tested in the tail-pinch test of coping and in the elevated plus-maze test that was performed under highly divergent conditions. Results Under the effects of URB597, rats focused their behavior more on the discomfort-inducing clamp in the tail pinch test, i.e. they coped with the challenge more actively. In the elevated plus-maze, URB597-treated rats demonstrated an autonomous behavioral control by reducing both "wariness" induced by aversive conditions and "carelessness" resulting from favorable conditions. Conclusions URB597 treatment induced behavioral changes indicative of a shift towards active coping with challenges. This behavioral change appears compatible with the previously suggested role of endocannabinoids in emotional homeostasis. Albeit further studies are required to characterize the role of endocannabinoids in coping, these findings suggest that the enhancement of endocannabinoid signaling may become a therapeutic option in emotional disorders characterized by passive coping (e.g. anxiety and depression) and in physical diseases where active coping is therapeutically desirable. PMID:23743650

  6. FAAH genetic variation enhances fronto-amygdala function in mouse and human

    PubMed Central

    Dincheva, Iva; Drysdale, Andrew T.; Hartley, Catherine A.; Johnson, David C.; Jing, Deqiang; King, Elizabeth C.; Ra, Stephen; Gray, Megan; Yang, Ruirong; DeGruccio, Ann Marie; Huang, Chienchun; Cravatt, Benjamin F.; Glatt, Charles E.; Hill, Matthew N.; Casey, B. J.; Lee, Francis S.

    2015-01-01

    Cross-species studies enable rapid translational discovery and produce the broadest impact when both mechanism and phenotype are consistent across organisms. We developed a knock-in mouse that biologically recapitulates a common human mutation in the gene for fatty acid amide hydrolase (FAAH) (C385A; rs324420), the primary catabolic enzyme for the endocannabinoid anandamide. This common polymorphism impacts the expression and activity of FAAH, thereby increasing anandamide levels. Here, we show that the genetic knock-in mouse and human variant allele carriers exhibit parallel alterations in biochemisty, neurocircuitry, and behavior. Specifically, there is reduced FAAH expression associated with the variant allele that selectively enhances fronto-amygdala connectivity and fear extinction learning, and decreases anxiety-like behaviors. These results suggest a gain-of-function in fear regulation and may indicate for whom and for what anxiety symptoms FAAH inhibitors or exposure-based therapies will be most efficacious, bridging an important translational gap between the mouse and human. PMID:25731744

  7. FAAH genetic variation enhances fronto-amygdala function in mouse and human.

    PubMed

    Dincheva, Iva; Drysdale, Andrew T; Hartley, Catherine A; Johnson, David C; Jing, Deqiang; King, Elizabeth C; Ra, Stephen; Gray, J Megan; Yang, Ruirong; DeGruccio, Ann Marie; Huang, Chienchun; Cravatt, Benjamin F; Glatt, Charles E; Hill, Matthew N; Casey, B J; Lee, Francis S

    2015-01-01

    Cross-species studies enable rapid translational discovery and produce the broadest impact when both mechanism and phenotype are consistent across organisms. We developed a knock-in mouse that biologically recapitulates a common human mutation in the gene for fatty acid amide hydrolase (FAAH) (C385A; rs324420), the primary catabolic enzyme for the endocannabinoid anandamide. This common polymorphism impacts the expression and activity of FAAH, thereby increasing anandamide levels. Here, we show that the genetic knock-in mouse and human variant allele carriers exhibit parallel alterations in biochemisty, neurocircuitry and behaviour. Specifically, there is reduced FAAH expression associated with the variant allele that selectively enhances fronto-amygdala connectivity and fear extinction learning, and decreases anxiety-like behaviours. These results suggest a gain of function in fear regulation and may indicate for whom and for what anxiety symptoms FAAH inhibitors or exposure-based therapies will be most efficacious, bridging an important translational gap between the mouse and human. PMID:25731744

  8. Macamides and their synthetic analogs: evaluation of in vitro FAAH inhibition.

    PubMed

    Wu, Hui; Kelley, Charles J; Pino-Figueroa, Alejandro; Vu, Huyen D; Maher, Timothy J

    2013-09-01

    Maca (Lepidium meyenii), a traditional food crop of the Peruvian Andes is now widely touted as a dietary supplement. Among the various chemical constituents isolated from the plant are a unique series of non-polar, long-chain fatty acid N-benzylamides known as macamides. We have synthesized 11 of the 19 reported macamides and have tested each as potential inhibitors of the human enzyme, fatty acid amide hydrolase (FAAH). The five most potent macamides were FAAH inhibitors (IC50=10-17μM). These amides were derivatives of oleic, linoleic and linolenic acids and benzylamine or 3-methoxybenzylamine. Of the three compounds evaluated in a pre-incubation time study, two macamides were not irreversible inhibitors of FAAH. The third, a carbamate structurally related to macamides, was shown to be an irreversible inhibitor of FAAH (IC50=0.153μM). PMID:23891163

  9. Combined inhibition of FAAH and COX produces enhanced anti-allodynic effects in mouse neuropathic and inflammatory pain models

    PubMed Central

    Grim, Travis W.; Ghosh, Sudeshna; Hsu, Ku-Lung; Cravatt, Benjamin F.; Kinsey, Steven G.; Lichtman, Aron H.

    2014-01-01

    Common pharmacological treatments of neuropathic and chronic inflammatory pain conditions generally lack efficacy and/or are associated with significant untoward side effects. However, recent preclinical data indicate that combined inhibition of cyclooxygenase (COX) and fatty acid amide hydrolase (FAAH), the primary catabolic enzyme of the endocannabinoid N-arachidonoylethanolamine (anandamide; AEA), produces enhanced antinociceptive effects in a variety of murine models of pain. Accordingly, the primary objective of the present study was to investigate the consequences of co-administration of the COX inhibitor diclofenac and the highly selective FAAH inhibitor PF-3845 in models of neuropathic pain (i.e., chronic constrictive injury of the sciatic nerve (CCI)) and inflammatory pain induced by an intraplantar injection of carrageenan. Here, we report that combined administration of subthreshold doses of these drugs produced enhanced antinociceptive effects in CCI and carrageenan pain models, the latter of which was demonstrated to require both CB1 and CB2 receptors. The combined administration of subthreshold doses of these drugs also increased AEA levels and decreased prostaglandin levels in whole brain. Together, these data add to the growing research that dual blockade of FAAH and COX represents a potential therapeutic strategy for the treatment of neuropathic and inflammatory pain states. PMID:25058512

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

    PubMed

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

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

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

    PubMed Central

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

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

  12. Optimization of 1,2,5-Thiadiazole Carbamates as Potent and Selective ABHD6 Inhibitors #

    PubMed Central

    Patel, Jayendra Z.; Nevalainen, Tapio J.; Savinainen, Juha R.; Adams, Yahaya; Laitinen, Tuomo; Runyon, Robert S.; Vaara, Miia; Ahenkorah, Stephen; Kaczor, Agnieszka A.; Navia-Paldanius, Dina; Gynther, Mikko; Aaltonen, Niina; Joharapurkar, Amit A.; Jain, Mukul R.; Haka, Abigail S.; Maxfield, Frederick R.; Laitinen, Jarmo T.; Parkkari, Teija

    2015-01-01

    At present, inhibitors of α/β-hydrolase domain 6 (ABHD6) are viewed as a promising approach to treat inflammation and metabolic disorders. This article describes the optimization of 1,2,5-thiadiazole carbamates as ABHD6 inhibitors. Altogether, 34 compounds were synthesized and their inhibitory activity was tested using lysates of HEK293 cells transiently expressing human ABHD6 (hABHD6). Among the compound series, 4-morpholino-1,2,5-thiadiazol-3-yl cyclooctyl(methyl)carbamate (JZP-430, 55) potently and irreversibly inhibited hABHD6 (IC50 44 nM) and showed good selectivity (∼230 fold) over fatty acid amide hydrolase (FAAH) and lysosomal acid lipase (LAL), the main off-targets of related compounds. Additionally, activity-based protein profiling (ABPP) indicated that compound 55 (JZP-430) displayed good selectivity among the serine hydrolases of mouse brain membrane proteome. PMID:25504894

  13. Sulfonyl fluoride inhibitors of fatty acid amide hydrolase.

    PubMed

    Alapafuja, Shakiru O; Nikas, Spyros P; Bharathan, Indu T; Shukla, Vidyanand G; Nasr, Mahmoud L; Bowman, Anna L; Zvonok, Nikolai; Li, Jing; Shi, Xiaomeng; Engen, John R; Makriyannis, Alexandros

    2012-11-26

    Sulfonyl fluorides are known to inhibit esterases. Early work from our laboratory has identified hexadecyl sulfonylfluoride (AM374) as a potent in vitro and in vivo inhibitor of fatty acid amide hydrolase (FAAH). We now report on later generation sulfonyl fluoride analogs that exhibit potent and selective inhibition of FAAH. Using recombinant rat and human FAAH, we show that 5-(4-hydroxyphenyl)pentanesulfonyl fluoride (AM3506) has similar inhibitory activity for both the rat and the human enzyme, while rapid dilution assays and mass spectrometry analysis suggest that the compound is a covalent modifier for FAAH and inhibits its action in an irreversible manner. Our SAR results are highlighted by molecular docking of key analogs. PMID:23083016

  14. 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

  15. Potent and Selective α-Ketoheterocycle-Based Inhibitors of the Anandamide and Oleamide Catabolizing Enzyme, Fatty Acid Amide Hydrolase

    PubMed Central

    Romero, F. Anthony; Du, Wu; Hwang, Inkyu; Rayl, Thomas J.; Kimball, F. Scott; Leung, Donmienne; Hoover, Heather S.; Apodaca, Richard L.; Breitenbucher, J. Guy; Cravatt, Benjamin F.; Boger, Dale L.

    2008-01-01

    A study of the structure–activity relationships (SAR) of 2f (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the 5-position of the oxazole. Examination of a series of substituted benzene derivatives (12–14) revealed that the optimal position for substitution was the meta-position with selected members approaching or exceeding the potency of 2f. Concurrent with these studies, the effect of substitution on the pyridine ring of 2f was also examined. A series of small, non-aromatic C5-substituents was also explored and revealed that the Ki follows a well-defined correlation with the Hammett σp constant (ρ = 3.01, R2 = 0.91) in which electron-withdrawing substituents enhance potency leading to inhibitors with Ki’s as low as 400 pM (20n). Proteomic-wide screening of the inhibitors revealed that most are exquisitely selective for FAAH over all other mammalian proteases reversing the 100-fold preference of 20a (C5 substituent = H) for the enzyme TGH. PMID:17279740

  16. The Molecular Basis for Dual Fatty Acid Amide Hydrolase (FAAH)/Cyclooxygenase (COX) Inhibition.

    PubMed

    Palermo, Giulia; Favia, Angelo D; Convertino, Marino; De Vivo, Marco

    2016-06-20

    The design of multitarget-directed ligands is a promising strategy for discovering innovative drugs. Here, we report a mechanistic study that clarifies key aspects of the dual inhibition of the fatty acid amide hydrolase (FAAH) and the cyclooxygenase (COX) enzymes by a new multitarget-directed ligand named ARN2508 (2-[3-fluoro-4-[3-(hexylcarbamoyloxy)phenyl]phenyl]propanoic acid). This potent dual inhibitor combines, in a single scaffold, the pharmacophoric elements often needed to block FAAH and COX, that is, a carbamate moiety and the 2-arylpropionic acid functionality, respectively. Molecular modeling and molecular dynamics simulations suggest that ARN2508 uses a noncovalent mechanism of inhibition to block COXs, while inhibiting FAAH via the acetylation of the catalytic Ser241, in line with previous experimental evidence for covalent FAAH inhibition. This study proposes the molecular basis for the dual FAAH/COX inhibition by this novel hybrid scaffold, stimulating further experimental studies and offering new insights for the rational design of novel anti-inflammatory agents that simultaneously act on FAAH and COX. PMID:26593700

  17. Corrosion inhibitor selection for wet pipelines

    SciTech Connect

    Buck, E.

    1995-12-31

    Selection of corrosion inhibitors for wet pipelines is based on laboratory testing and field confirmation. Both the use and selection of corrosion inhibitors are driven by economics. Economics of alternative corrosion protection methods is not treated in this paper, but the economics of proper inhibitor selection are. The key to successful inhibitor selection is careful analysis of pipeline flow conditions and experimental emulation of its corrosive environment. Transportation of inhibitor to the corroding interface must be explicitly considered in the emulation. Standard corrosion rate measurement methods are used to evaluate inhibitors. Inhibitor properties tabulated during evaluation form a core database for continuing quality control.

  18. Inhibition of FAAH reduces nitroglycerin-induced migraine-like pain and trigeminal neuronal hyperactivity in mice.

    PubMed

    Nozaki, Chihiro; Markert, Astrid; Zimmer, Andreas

    2015-08-01

    There is evidence to suggest that a dysregulation of endocannabinoid signaling may contribute to the etiology and pathophysiology of migraine. Thus, patients suffering from chronic migraine or medication overuse headache showed alterations in the activity of the arachidonoylethanolamide (AEA) degrading enzyme fatty acid amide hydrolase (FAAH) and a specific AEA membrane transporter, alongside with changes in AEA levels. The precise role of different endocannabinoid system components is, however, not clear. We have therefore investigated mice with a genetic deletion of the two main cannabinoid receptors CB1 and CB2, or the main endocannabinoid degrading enzymes, FAAH and monoacylglycerol lipase (MAGL), which degrades 2-arachidonoylglycerol (2-AG), in a nitroglycerine-induced animal model of migraine. We found that nitroglycerin-induced mechanical allodynia and neuronal activation of the trigeminal nucleus were completely abolished in FAAH-deficient mice. To validate these results, we used two structurally different FAAH inhibitors, URB597 and PF3945. Both inhibitors also dose-dependently blocked nitroglycerin-induced hyperalgesia and the activation of trigeminal neurons. The effects of the genetic deletion of pharmacological blockade of FAAH are mediated by CB1 receptors, because they were completely disrupted with the CB1 antagonist rimonabant. These results identify FAAH as a target for migraine pharmacotherapy. PMID:25910421

  19. FAAH-mediated modulation of TLR3-induced neuroinflammation in the rat hippocampus.

    PubMed

    Henry, Rebecca J; Kerr, Daniel M; Finn, David P; Roche, Michelle

    2014-11-15

    The present study examined the effect of enhancing fatty acid amide hydrolase (FAAH) substrate levels in vivo on Toll-like receptor (TLR)3-induced neuroinflammation. Systemic and central (i.c.v.) administration of the FAAH inhibitor URB597 increased hippocampal levels of the N-acylethanolamines palmitoylethanolamide and oleoylethanolamide, but not anandamide. Systemic URB597 increased IFNα, IFNγ and IL-6 expression following TLR3 activation and attenuated TLR3-induced IL-1β and TNFα expression. In comparison, central URB597 administration attenuated the TLR3-induced increase in TNFα and IFNγ expression (and associated downstream genes IP-10 and SOCS1), while concurrently increasing IL-10 expression. These data support an important role for FAAH-mediated regulation of TLR3-induced neuroinflammatory responses. PMID:25245162

  20. Inhibition of FAAH and activation of PPAR: New approaches to the treatment of cognitive dysfunction and drug addiction

    PubMed Central

    Panlilio, Leigh V.; Justinova, Zuzana; Goldberg, Steven R.

    2013-01-01

    Enhancing the effects of endogenously-released cannabinoid ligands in the brain might provide therapeutic effects more safely and effectively than administering drugs that act directly at the cannabinoid receptor. Inhibitors of fatty acid amide hydrolase (FAAH) prevent the breakdown of endogenous ligands for cannabinoid receptors and peroxisome proliferator-activated receptors (PPAR), prolonging and enhancing the effects of these ligands when they are naturally released. This review considers recent research on the effects of FAAH inhibitors and PPAR activators in animal models of addiction and cognition (specifically learning and memory). These studies show that FAAH inhibitors can produce potentially therapeutic effects, some through cannabinoid receptors and some through PPAR. These effects include enhancing certain forms of learning, counteracting the rewarding effects of nicotine and alcohol, relieving symptoms of withdrawal from cannabis and other drugs, and protecting against relapse-like reinstatement of drug self-administration. Since FAAH inhibition might have a wide range of therapeutic actions but might also share some of the adverse effects of cannabis, it is noteworthy that at least one FAAH-inhibiting drug (URB597) has been found to have potentially beneficial effects but no indication of liability for abuse or dependence. Although these areas of research are new, the preliminary evidence indicates that they might lead to improved therapeutic interventions and a better understanding of the brain mechanisms underlying addiction and memory. PMID:23333350

  1. [Recent development of selective cyclooxygenase-2 inhibitors].

    PubMed

    Kawai, Shinichi

    2002-12-01

    Nonsteroidal anti-inflammatory drugs(NSAIDs) are clinically effective against the inflammatory symptoms of rheumatoid arthritis. Recent attention has been focused on selective cyclooxygenase(COX)-2 inhibitors, a type of NSAID that inhibits a subtype of COX. Because of the different actions of COX-1 and COX-2, selective COX-2 inhibitors were expected to reduce adverse reactions such as gastrointestinal disorders. Various clinical studies have confirmed that the efficacy of COX-2 inhibitors for RA is similar to that of conventional NSAIDs, but they cause fewer severe gastrointestinal disorders. The incidence of complications related to renal dysfunction, such as edema and hypertension, is not different. Patients using selective COX-2 inhibitors have recently been reported to show an increase in thrombotic complications such as myocardial infarction. Therefore, more data on adverse events should be collected in the future from large-scale clinical studies to further clarify the actual value of selective COX-2 inhibitors. PMID:12510364

  2. Selective serotonin reuptake inhibitor exposure.

    PubMed

    Fitzgerald, Kevin T; Bronstein, Alvin C

    2013-02-01

    Many antidepressants inhibit serotonin or norepinephrine reuptake or both to achieve their clinical effect. The selective serotonin reuptake inhibitor class of antidepressants (SSRIs) includes citalopram, escitalopram (active enantiomer of citalopram), fluoxetine, fluvoxamine, paroxetine, and sertraline. The SSRIs are as effective as tricyclic antidepressants in treatment of major depression with less significant side effects. As a result, they have become the largest class of medications prescribed to humans for depression. They are also used to treat obsessive-compulsive disorder, panic disorders, alcoholism, obesity, migraines, and chronic pain. An SSRI (fluoxetine) has been approved for veterinary use in treatment of canine separation anxiety. SSRIs act specifically on synaptic serotonin concentrations by blocking its reuptake in the presynapse and increasing levels in the presynaptic membrane. Clinical signs of SSRI overdose result from excessive amounts of serotonin in the central nervous system. These signs include nausea, vomiting, mydriasis, hypersalivation, and hyperthermia. Clinical signs are dose dependent and higher dosages may result in the serotonin syndrome that manifests itself as ataxia, tremors, muscle rigidity, hyperthermia, diarrhea, and seizures. Current studies reveal no increase in appearance of any specific clinical signs of serotonin toxicity with regard to any SSRI medication. In people, citalopram has been reported to have an increased risk of electrocardiographic abnormalities. Diagnosis of SSRI poisoning is based on history, clinical signs, and response to therapy. No single clinical test is currently available to confirm SSRI toxicosis. The goals of treatment in this intoxication are to support the animal, prevent further absorption of the drug, support the central nervous system, control hyperthermia, and halt any seizure activity. The relative safety of the SSRIs in overdose despite the occurrence of serotonin syndrome makes them

  3. On the selectivity of neuronal NOS inhibitors

    PubMed Central

    Pigott, B; Bartus, K; Garthwaite, J

    2013-01-01

    Background and Purpose Isoform-selective inhibitors of NOS enzymes are desirable as research tools and for potential therapeutic purposes. Vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine (l-VNIO) and Nω-propyl-l-arginine (NPA) purportedly have good selectivity for neuronal over endothelial NOS under cell-free conditions, as does N-[(3-aminomethyl)benzyl]acetamidine (1400W), which is primarily an inducible NOS inhibitor. Although used in numerous investigations in vitro and in vivo, there have been surprisingly few tests of the potency and selectivity of these compounds in cells. This study addresses this deficiency and evaluates the activity of new and potentially better pyrrolidine-based compounds. Experimental Approach The inhibitors were evaluated by measuring their effect on NMDA-evoked cGMP accumulation in rodent hippocampal slices, a response dependent on neuronal NOS, and ACh-evoked cGMP synthesis in aortic rings of the same animals, an endothelial NOS-dependent phenomenon. Key Results l-VNIO, NPA and 1400W inhibited responses in both tissues but all showed less than fivefold higher potency in the hippocampus than in the aorta, implying useless selectivity for neuronal over endothelial NOS at the tissue level. In addition, the inhibitors had a 25-fold lower potency in the hippocampus than reported previously, the IC50 values being approximately 1 μM for l-VNIO and NPA, and 150 μM for 1400W. Pyrrolidine-based inhibitors were similarly weak and nonselective. Conclusion and Implications The results suggest that l-VNIO, NPA and 1400W, as well as the newer pyrrolidine-type inhibitors, cannot be used as neuronal NOS inhibitors in cells without stringent verification. The identification of inhibitors with useable selectivity in cells and tissues remains an important goal. PMID:23072468

  4. Fatty Acid Amide Hydrolase (FAAH) Inhibition Enhances Memory Acquisition through Activation of PPAR-alpha Nuclear Receptors

    ERIC Educational Resources Information Center

    Mazzola, Carmen; Medalie, Julie; Scherma, Maria; Panlilio, Leigh V.; Solinas, Marcello; Tanda, Gianluigi; Drago, Filippo; Cadet, Jean Lud; Goldberg, Steven R.; Yasar, Sevil

    2009-01-01

    Inhibitors of fatty acid amide hydrolase (FAAH) increase endogenous levels of anandamide (a cannabinoid CB[subscript 1]-receptor ligand) and oleoylethanolamide and palmitoylethanolamide (OEA and PEA, ligands for alpha-type peroxisome proliferator-activated nuclear receptors, PPAR-alpha) when and where they are naturally released in the brain.…

  5. Genetically reduced FAAH activity may be a risk for the development of anxiety and depression in persons with repetitive childhood trauma.

    PubMed

    Lazary, Judit; Eszlari, Nora; Juhasz, Gabriella; Bagdy, Gyorgy

    2016-06-01

    Fatty acid amide hydrolase (FAAH) inhibitors are addressed for promising anxiolytics, but human studies on genetically reduced FAAH activity, stress and affective phenotypes are scarce. We investigated the effect of a functional polymorphism of FAAH (FAAH C385A or rs324420; low FAAH activity and high anandamide concentration are associated with the A allele) together with childhood adversity on the anxious and depressive phenotypes in 858 subjects from the general population. Phenotypes were measured by the Zung Self-Rating Depression Scale (ZSDS), the depression and anxiety subscales of the Brief Symptom Inventory (BSI-DEP, BSI-ANX) and the State-Trait Anxiety scales (STAI-S, STAI-T). Childhood Adversity Questionnaire (CHA) was used to assess early life traumas. Frequency of the A allele was greater among subjects with high ZSDS scores compared to the CC genotype. Furthermore, FAAH C385A and the CHA have shown a robust gene-environment interaction, namely, significantly higher anxiety and depression scores were exhibited by individuals carrying the A allele if they had high CHA scores compared to CC carriers. These data provided preliminary evidence that genetically reduced FAAH activity and repetitive stress in the childhood are associated with increased vulnerability for anxiety and depression in later life. Our results together with earlier experimental data suggest that permanently elevated anandamide level together with early life stress may cause a lifelong damage on stress response probably via the downregulation of CB1R during the neurodevelopment in the brain. It may also point to pharmacogenomic consequences, namely ineffectiveness or adverse effects of FAAH inhibitors in this subpopulation. PMID:27005594

  6. Selective serotonin reuptake inhibitor discontinuation during pregnancy

    PubMed Central

    Ejaz, Resham; Leibson, Tom; Koren, Gideon

    2014-01-01

    Abstract Question I have a patient who discontinued her selective serotonin reuptake inhibitor in pregnancy against my advice owing to fears it might affect the baby. She eventually attempted suicide. How can we deal effectively with this situation? Answer The “cold turkey” discontinuation of needed antidepressants is a serious public health issue strengthened by fears and misinformation. It is very important for physicians to ensure that evidence-based information is given to women in a way that is easy to understand. The risks of untreated moderate to severe depression far outweigh the theoretical risks of taking selective serotonin reuptake inhibitors. PMID:25642484

  7. Selective Phosphodiesterase 4B Inhibitors: A Review

    PubMed Central

    Azam, Mohammed Afzal; Tripuraneni, Naga Srinivas

    2014-01-01

    Abstract Phosphodiesterase 4B (PDE4B) is a member of the phosphodiesterase family of proteins that plays a critical role in regulating intracellular levels of cyclic adenosine monophosphate (cAMP) by controlling its rate of degradation. It has been demonstrated that this isoform is involved in the orchestra of events which includes inflammation, schizophrenia, cancers, chronic obstructive pulmonary disease, contractility of the myocardium, and psoriatic arthritis. Phosphodiesterase 4B has constituted an interesting target for drug development. In recent years, a number of PDE4B inhibitors have been developed for their use as therapeutic agents. In this review, an up-to-date status of the inhibitors investigated for the inhibition of PDE4B has been given so that this rich source of structural information of presently known PDE4B inhibitors could be helpful in generating a selective and potent inhibitor of PDE4B. PMID:25853062

  8. Inhibitors Selective for Mycobacterial Versus Human Proteasomes

    SciTech Connect

    Lin, G.; Li, D; Sorio de Carvalho, L; Deng, H; Tao, H; Vogt, G; Wu, K; Schneider, J; Chidawanyika, T; et. al.

    2009-01-01

    Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-one compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.

  9. Identification of potent, selective KDM5 inhibitors.

    PubMed

    Gehling, Victor S; Bellon, Steven F; Harmange, Jean-Christophe; LeBlanc, Yves; Poy, Florence; Odate, Shobu; Buker, Shane; Lan, Fei; Arora, Shilpi; Williamson, Kaylyn E; Sandy, Peter; Cummings, Richard T; Bailey, Christopher M; Bergeron, Louise; Mao, Weifeng; Gustafson, Amy; Liu, Yichin; VanderPorten, Erica; Audia, James E; Trojer, Patrick; Albrecht, Brian K

    2016-09-01

    This communication describes the identification and optimization of a series of pan-KDM5 inhibitors derived from compound 1, a hit initially identified against KDM4C. Compound 1 was optimized to afford compound 20, a 10nM inhibitor of KDM5A. Compound 20 is highly selective for the KDM5 enzymes versus other histone lysine demethylases and demonstrates activity in a cellular assay measuring the increase in global histone 3 lysine 4 tri-methylation (H3K4me3). In addition compound 20 has good ADME properties, excellent mouse PK, and is a suitable starting point for further optimization. PMID:27476424

  10. Binding and Inactivation Mechanism of a Humanized Fatty Acid Amide Hydrolase by [alpha]-Ketoheterocycle Inhibitors Revealed from Cocrystal Structures

    SciTech Connect

    Mileni, Mauro; Garfunkle, Joie; DeMartino, Jessica K.; Cravatt, Benjamin F.; Boger, Dale L.; Stevens, Raymond C.

    2010-08-17

    The cocrystal X-ray structures of two isomeric {alpha}-ketooxazole inhibitors (1 (OL-135) and 2) bound to fatty acid amide hydrolase (FAAH), a key enzymatic regulator of endocannabinoid signaling, are disclosed. The active site catalytic Ser241 is covalently bound to the inhibitors electrophilic carbonyl groups, providing the first structures of FAAH bound to an inhibitor as a deprotonated hemiketal mimicking the enzymatic tetrahedral intermediate. The work also offers a detailed view of the oxyanion hole and an exceptional 'in-action' depiction of the unusual Ser-Ser-Lys catalytic triad. These structures capture the first picture of inhibitors that span the active site into the cytosolic port providing new insights that help to explain FAAH's interaction with substrate leaving groups and their role in modulating inhibitor potency and selectivity. The role for the activating central heterocycle is clearly defined and distinguished from that observed in prior applications with serine proteases, reconciling the large electronic effect of attached substituents found unique to this class of inhibitors with FAAH. Additional striking active site flexibility is seen upon binding of the inhibitors, providing insights into the existence of a now well-defined membrane access channel with the disappearance of a spatially independent portion of the acyl chain-binding pocket. Finally, comparison of the structures of OL-135 (1) and its isomer 2 indicates that they bind identically to FAAH, albeit with reversed orientations of the central activating heterocycle, revealing that the terminal 2-pyridyl substituent and the acyl chain phenyl group provide key anchoring interactions and confirming the distinguishing role of the activating oxazole.

  11. Selective Water-Soluble Gelatinase Inhibitor Prodrugs

    PubMed Central

    Gooyit, Major; Lee, Mijoon; Schroeder, Valerie A.; Ikejiri, Masahiro; Suckow, Mark A.; Mobashery, Shahriar; Chang, Mayland

    2011-01-01

    SB-3CT (1), a selective and potent thiirane-based gelatinase inhibitor, is effective in animal models of cancer metastasis and stroke; however, it is limited by poor aqueous solubility and extensive metabolism. We addressed these issues by blocking the primary site of metabolism and capitalizing on a prodrug strategy to achieve >5000-fold increased solubility. The amide prodrugs were quantitatively hydrolyzed in human blood to a potent gelatinase inhibitor, ND-322 (3). The arginyl amide prodrug (ND-478, 5d) was metabolically stable in mouse, rat, and human liver microsomes. Both 5d and 3 were non-mutagenic in the Ames II mutagenicity assay. The prodrug 5d showed moderate clearance of 0.0582 L/min/kg, remained mostly in the extracellular fluid compartment (Vd = 0.0978 L/kg), and had a terminal half-life of >4 h. The prodrug 5d had superior pharmacokinetic properties than 3, making the thiirane class of selective gelatinase inhibitors suitable for intravenous administration in treatment of acute gelatinase-dependent diseases. PMID:21866961

  12. Inside HDACs with more selective HDAC inhibitors.

    PubMed

    Roche, Joëlle; Bertrand, Philippe

    2016-10-01

    Inhibitors of histone deacetylases (HDACs) are nowadays part of the therapeutic arsenal mainly against cancers, with four compounds approved by the Food and Drug Administration. During the last five years, several groups have made continuous efforts to improve this class of compounds, designing more selective compounds or compounds with multiple capacities. After a survey of the HDAC biology and structures, this review summarizes the results of the chemists working in this field, and highlights when possible the behavior of the molecules inside their targets. PMID:27318122

  13. [PCSK9 inhibitors : Recommendations for patient selection].

    PubMed

    Laufs, U; Custodis, F; Werner, C

    2016-06-01

    The 2 or 4‑week subcutaneous therapy with the recently approved antibodies alirocumab and evolocumab for inhibition of proprotein convertase subtilisin-kexin type 9 (PCSK9) reduces low-density lipoprotein cholesterol (LDL-C) in addition to statins and ezetimibe by 50-60 %. The therapy is well-tolerated. The safety profile in the published studies is comparable to placebo. Outcome data and information on long-term safety and the influence on cardiovascular events are not yet available but the results of several large trials are expected in 2016-2018. At present (spring 2016) PCSK9 inhibitors represent an option for selected patients with a high cardiovascular risk and high LDL-C despite treatment with the maximum tolerated oral lipid-lowering therapy. This group includes selected patients with familial hypercholesterolemia and high-risk individuals with statin-associated muscle symptoms (SAMS). PMID:27207595

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

    PubMed Central

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

    2016-01-01

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

  15. Structural selectivity of human SGLT inhibitors

    PubMed Central

    Hummel, Charles S.; Lu, Chuan; Liu, Jie; Ghezzi, Chiari; Hirayama, Bruce A.; Loo, Donald D. F.; Kepe, Vladimir; Barrio, Jorge R.

    2012-01-01

    Human Na+-d-glucose cotransporter (hSGLT) inhibitors constitute the newest class of diabetes drugs, blocking up to 50% of renal glucose reabsorption in vivo. These drugs have potential for widespread use in the diabetes epidemic, but how they work at a molecular level is poorly understood. Here, we use electrophysiological methods to assess how they block Na+-d-glucose cotransporter SGLT1 and SGLT2 expressed in human embryonic kidney 293T (HEK-293T) cells and compared them to the classic SGLT inhibitor phlorizin. Dapagliflozin [(1S)-1,5,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-d-glucitol], two structural analogs, and the aglycones of phlorizin and dapagliflozin were investigated in detail. Dapagliflozin and fluoro-dapagliflozin [(1S)-1,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-4-F-4-deoxy-d-glucitol] blocked glucose transport and glucose-coupled currents with ≈100-fold specificity for hSGLT2 (Ki = 6 nM) over hSGLT1 (Ki = 400 nM). As galactose is a poor substrate for SGLT2, it was surprising that galacto-dapagliflozin [(1S)-1,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-d-galactitol] was a selective inhibitor of hSGLT2, but was less potent than dapagliflozin for both transporters (hSGLT2 Ki = 25 nM, hSGLT1 Ki = 25,000 nM). Phlorizin and galacto-dapagliflozin rapidly dissociated from SGLT2 [half-time off rate (t1/2,Off) ≈ 20–30 s], while dapagliflozin and fluoro-dapagliflozin dissociated from hSGLT2 at a rate 10-fold slower (t1/2,Off ≥ 180 s). Phlorizin was unable to exchange with dapagliflozin bound to hSGLT2. In contrast, dapagliflozin, fluoro-dapagliflozin, and galacto-dapagliflozin dissociated quickly from hSGLT1 (t1/2,Off = 1–2 s), and phlorizin readily exchanged with dapagliflozin bound to hSGLT1. The aglycones of phlorizin and dapagliflozin were poor inhibitors of both hSGLT2 and hSGLT1 with Ki values > 100 μM. These results show that inhibitor binding to SGLTs is composed of two synergistic forces

  16. Amygdala FAAH and anandamide: mediating protection and recovery from stress.

    PubMed

    Gunduz-Cinar, Ozge; Hill, Matthew N; McEwen, Bruce S; Holmes, Andrew

    2013-11-01

    A long-standing literature linking endocannabinoids (ECBs) to stress, fear, and anxiety has led to growing interest in developing novel anxiolytics targeting the ECB system. Following rapid on-demand biosynthesis and degradation upon neuronal activation, the ECB N-arachidonoylethanolamide (anandamide, AEA) is actively degraded by the serine hydrolase enzyme, fatty acid amide hydrolase (FAAH). Exposure to stress rapidly mobilizes FAAH to deplete the signaling pool of AEA and increase neuronal excitability in a key anxiety-mediating region--the basolateral amygdala (BLA). Gene deletion or pharmacological inhibition of FAAH prevents stress-induced reductions in AEA and associated increases in BLA dendritic hypertrophy and anxiety-like behavior. Additionally, inhibition of FAAH facilitates long-term fear extinction and rescues deficient fear extinction in rodent models by enhancing AEA-CB1 (cannabinoid type 1) receptor signaling and synaptic plasticity in the BLA. These preclinical findings propose restoring deficient BLA AEA levels by pharmacologically inhibiting FAAH as a mechanism to therapeutically mitigate the effects of traumatic stress. PMID:24325918

  17. Characterization of tunable piperidine and piperazine carbamates as inhibitors of endocannabinoid hydrolases

    PubMed Central

    Long, Jonathan Z.; Jin, Xin; Adibekian, Alexander; Li, Weiwei; Cravatt, Benjamin F.

    2010-01-01

    Monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) are two enzymes from the serine hydrolase superfamily that degrade the endocannabinoids 2-arachidonoylglycerol and anandamide, respectively. We have recently discovered that MAGL and FAAH are both inhibited by carbamates bearing an N-piperidine/piperazine group. Piperidine/piperazine carbamates show excellent in vivo activity, raising brain endocannabinoid levels and producing CB1-dependent behavioral effects in mice, suggesting that they represent a promising class of inhibitors for studying the endogenous functions of MAGL and FAAH. Herein, we disclose a full account of the syntheses, structure-activity relationships, and inhibitory activities of piperidine/piperazine carbamates against members of the serine hydrolase family. These scaffolds can be tuned for MAGL-selective or dual MAGL-FAAH inhibition by the attachment of an appropriately substituted bisarylcarbinol or aryloxybenzyl moiety, respectively, on the piperidine/piperazine ring. Modifications to the piperidine/piperazine ring ablated inhibitory activity, suggesting a strict requirement for a six-member ring to maintain potency. PMID:20099888

  18. Selective serotonin-reuptake inhibitors: an update.

    PubMed

    Masand, P S; Gupta, S

    1999-01-01

    Selective serotonin-reuptake inhibitors (SSRIs), including fluoxetine, sertraline, paroxetine, fluvoxamine, and citalopram, represent an important advance in the pharmacotherapy of mood and other disorders. They are chemically unrelated to tricyclic, heterocyclic, and other first-generation antidepressants. SSRIs are the treatment of choice for many indications, including major depression, dysthymia, panic disorder, obsessive-compulsive disorder, eating disorders, and premenstrual dysphoric disorder, because of their efficacy, good side-effect profile, tolerability, and safety in overdose, as well as patient compliance. A review of the literature was conducted using Medline and the terms "SSRIs," "fluoxetine," "sertraline," "paroxetine," "fluvoxamine," and "citalopram." Articles were limited to those published in English within the last 15 years. The search revealed that indications for antidepressants include unipolar depression, dysthymia, bipolar depression, treatment-resistant depression, depression in the medically ill, panic disorder, obsessive-compulsive disorder, eating disorders, social phobia, and premenstrual dysphoric disorder. One SSRI, fluoxetine, has demonstrated safety in pregnancy. Side effects of SSRIs include gastrointestinal disturbances, headache, sedation, insomnia, activation, weight gain, impaired memory, excessive perspiration, paresthesia, and sexual dysfunction. PMID:10471245

  19. Fatty Acid Amide Hydrolase (FAAH), Acetylcholinesterase (AChE), and Butyrylcholinesterase (BuChE): Networked Targets for the Development of Carbamates as Potential Anti-Alzheimer's Disease Agents.

    PubMed

    Montanari, Serena; Scalvini, Laura; Bartolini, Manuela; Belluti, Federica; Gobbi, Silvia; Andrisano, Vincenza; Ligresti, Alessia; Di Marzo, Vincenzo; Rivara, Silvia; Mor, Marco; Bisi, Alessandra; Rampa, Angela

    2016-07-14

    The modulation of the endocannabinoid system is emerging as a viable avenue for the treatment of neurodegeneration, being involved in neuroprotective and anti-inflammatory processes. In particular, indirectly enhancing endocannabinoid signaling to therapeutic levels through FAAH inhibition might be beneficial for neurodegenerative disorders such as Alzheimer's disease, effectively preventing or slowing the progression of the disease. Hence, in the search for a more effective treatment for Alzheimer's disease, in this paper, the multitarget-directed ligand paradigm was applied to the design of carbamates able to simultaneously target the recently proposed endocannabinoid system and the classic cholinesterase system, and achieve effective dual FAAH/cholinesterase inhibitors. Among the two series of synthesized compounds, while some derivatives proved to be extremely potent on a single target, compounds 9 and 19 were identified as effective dual FAAH/ChE inhibitors, with well-balanced nanomolar activities. Thus, 9 and 19 might be considered as new promising candidates for Alzheimer's disease treatment. PMID:27309570

  20. FAAH inhibition enhances anandamide mediated anti-tumorigenic effects in non-small cell lung cancer by downregulating the EGF/EGFR pathway

    PubMed Central

    Ravi, Janani; Sneh, Amita; Shilo, Konstantin; Nasser, Mohd W.; Ganju, Ramesh K.

    2014-01-01

    The endocannabinoid anandamide (AEA), a neurotransmitter was shown to have anti-cancer effects. Fatty acid amide hydrolase (FAAH) metabolizes AEA and decreases its anti-tumorigenic activity. In this study, we have analyzed the role of FAAH inhibition in non-small cell lung cancer (NSCLC). We have shown that FAAH and CB1 receptor which is activated by AEA are expressed in lung adenocarcinoma patient samples and NSCLC cell lines A549 and H460. Since the synthetic analogue of anandamide (Met-F-AEA) did not possess significant anti-tumorigenic effects, we used Met-F-AEA in combination with FAAH inhibitor URB597 which significantly reduced EGF (epidermal growth factor)-induced proliferative and chemotactic activities in vitro when compared to anti-tumorigenic activity of Met-F-AEA alone. Further analysis of signaling mechanisms revealed that Met-F-AEA in combination with URB597 inhibits activation of EGFR and its downstream signaling ERK, AKT and NF-kB. In addition, it inhibited MMP2 secretion and stress fiber formation. We have also shown that the Met-F-AEA in combination with URB597 induces G0/G1 cell cycle arrest by downregulating cyclin D1 and CDK4 expressions, ultimately leading to apoptosis via activation of caspase-9 and PARP. Furthermore, the combination treatment inhibited tumor growth in a xenograft nude mouse model system. Tumors derived from Met-F-AEA and URB597 combination treated mice showed reduced EGFR, AKT and ERK activation and MMP2/MMP9 expressions when compared to Met-F-AEA or URB597 alone. Taken together, these data suggest in EGFR overexpressing NSCLC that the combination of Met-F-AEA with FAAH inhibitor resulted in superior therapeutic response compared to individual compound activity alone. PMID:24811863

  1. Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context

    PubMed Central

    Rivera, Patricia; Bindila, Laura; Pastor, Antoni; Pérez-Martín, Margarita; Pavón, Francisco J.; Serrano, Antonia; de la Torre, Rafael; Lutz, Beat; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3+ or BrdU+ cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3+), astroglia (GFAP+), and microglia (Iba1+ cells) were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day) at one dose/4-days resting or 5 doses (1 dose/day). Repeated URB597 treatment increased the plasma levels of the N-acylethanolamines oleoylethanolamide, palmitoylethanolamide and arachidonoylethanolamine, reduced the plasma levels of glucose, triglycerides and cholesterol, and induced a transitory body weight decrease. The hippocampi of repeated URB597-treated rats showed a reduced number of phospho-H3+ and BrdU+ subgranular cells as well as GFAP+, Iba1+ and cleaved caspase-3+ cells, which was accompanied with decreased hippocampal expression of the cannabinoid CB1 receptor gene Cnr1 and Faah. In the hypothalami of these rats, the number of phospho-H3+, GFAP+ and 3-weeks-old BrdU+ cells was specifically decreased. The reduced striatal expression of CB1 receptor in repeated URB597-treated rats was only associated with a reduced apoptosis. In contrast, the striatum of acute URB597-treated rats showed an increased number of subventricular proliferative, astroglial and apoptotic cells, which was accompanied with increased Faah expression. Main results indicated that FAAH inhibitor URB597 decreased neural proliferation, glia and apoptosis in a brain region-dependent manner, which were coupled to local changes in Faah and/or Cnr1 expression and a negative energy context. PMID:25870539

  2. Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context.

    PubMed

    Rivera, Patricia; Bindila, Laura; Pastor, Antoni; Pérez-Martín, Margarita; Pavón, Francisco J; Serrano, Antonia; de la Torre, Rafael; Lutz, Beat; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3(+) or BrdU(+) cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3(+)), astroglia (GFAP(+)), and microglia (Iba1(+) cells) were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day) at one dose/4-days resting or 5 doses (1 dose/day). Repeated URB597 treatment increased the plasma levels of the N-acylethanolamines oleoylethanolamide, palmitoylethanolamide and arachidonoylethanolamine, reduced the plasma levels of glucose, triglycerides and cholesterol, and induced a transitory body weight decrease. The hippocampi of repeated URB597-treated rats showed a reduced number of phospho-H3(+) and BrdU(+) subgranular cells as well as GFAP(+), Iba1(+) and cleaved caspase-3(+) cells, which was accompanied with decreased hippocampal expression of the cannabinoid CB1 receptor gene Cnr1 and Faah. In the hypothalami of these rats, the number of phospho-H3(+), GFAP(+) and 3-weeks-old BrdU(+) cells was specifically decreased. The reduced striatal expression of CB1 receptor in repeated URB597-treated rats was only associated with a reduced apoptosis. In contrast, the striatum of acute URB597-treated rats showed an increased number of subventricular proliferative, astroglial and apoptotic cells, which was accompanied with increased Faah expression. Main results indicated that FAAH inhibitor URB597 decreased neural proliferation, glia and apoptosis in a brain region-dependent manner, which were coupled to local changes in Faah and/or Cnr1 expression and a negative energy context. PMID:25870539

  3. Discovery of a selective irreversible BMX inhibitor for prostate cancer.

    PubMed

    Liu, Feiyang; Zhang, Xin; Weisberg, Ellen; Chen, Sen; Hur, Wooyoung; Wu, Hong; Zhao, Zheng; Wang, Wenchao; Mao, Mao; Cai, Changmeng; Simon, Nicholas I; Sanda, Takaomi; Wang, Jinhua; Look, A Thomas; Griffin, James D; Balk, Steven P; Liu, Qingsong; Gray, Nathanael S

    2013-07-19

    BMX is a member of the TEC family of nonreceptor tyrosine kinases. We have used structure-based drug design in conjunction with kinome profiling to develop a potent, selective, and irreversible BMX kinase inhibitor, BMX-IN-1, which covalently modifies Cys496. BMX-IN-1 inhibits the proliferation of Tel-BMX-transformed Ba/F3 cells at two digit nanomolar concentrations but requires single digit micromolar concentrations to inhibit the proliferation of prostate cancer cell lines. Using a combinatorial kinase inhibitor screening strategy, we discovered that the allosteric Akt inhibitor, MK2206, is able to potentiate BMX inhibitor's antiproliferation efficacy against prostate cancer cells. PMID:23594111

  4. Selective serotonin reuptake inhibitors for fibromyalgia syndrome

    PubMed Central

    Walitt, Brian; Urrútia, Gerard; Nishishinya, María Betina; Cantrell, Sarah E; Häuser, Winfried

    2016-01-01

    Background Fibromyalgia is a clinically well-defined chronic condition with a biopsychosocial aetiology. Fibromyalgia is characterized by chronic widespread musculoskeletal pain, sleep problems, cognitive dysfunction, and fatigue. Patients often report high disability levels and poor quality of life. Since there is no specific treatment that alters the pathogenesis of fibromyalgia, drug therapy focuses on pain reduction and improvement of other aversive symptoms. Objectives The objective was to assess the benefits and harms of selective serotonin reuptake inhibitors (SSRIs) in the treatment of fibromyalgia. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 5), MEDLINE (1966 to June 2014), EMBASE (1946 to June 2014), and the reference lists of reviewed articles. Selection criteria We selected all randomized, double-blind trials of SSRIs used for the treatment of fibromyalgia symptoms in adult participants. We considered the following SSRIs in this review: citalopram, fluoxetine, escitalopram, fluvoxamine, paroxetine, and sertraline. Data collection and analysis Three authors extracted the data of all included studies and assessed the risks of bias of the studies. We resolved discrepancies by discussion. Main results The quality of evidence was very low for each outcome. We downgraded the quality of evidence to very low due to concerns about risk of bias and studies with few participants. We included seven placebo-controlled studies, two with citalopram, three with fluoxetine and two with paroxetine, with a median study duration of eight weeks (4 to 16 weeks) and 383 participants, who were pooled together. All studies had one or more sources of potential major bias. There was a small (10%) difference in patients who reported a 30% pain reduction between SSRIs (56/172 (32.6%)) and placebo (39/171 (22.8%)) risk difference (RD) 0.10, 95% confidence interval (CI) 0.01 to 0.20; number needed to treat for an additional

  5. Acalabrutinib (ACP-196): a selective second-generation BTK inhibitor.

    PubMed

    Wu, Jingjing; Zhang, Mingzhi; Liu, Delong

    2016-01-01

    More and more targeted agents become available for B cell malignancies with increasing precision and potency. The first-in-class Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, has been in clinical use for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's macroglobulinemia. More selective BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being explored. Acalabrutinib (ACP-196) is a novel irreversible second-generation BTK inhibitor that was shown to be more potent and selective than ibrutinib. This review summarized the preclinical research and clinical data of acalabrutinib. PMID:26957112

  6. Triazaspirodimethoxybenzoyls as Selective Inhibitors of Mycobacterial Lipoamide Dehydrogenase

    SciTech Connect

    Bryk, Ruslana; Arango, Nancy; Venugopal, Aditya; Warren, J. David; Park, Yun-Hee; Patel, Mulchand S.; Lima, Christopher D.; Nathan, Carl

    2010-06-25

    Mycobacterium tuberculosis (Mtb) remains the leading single cause of death from bacterial infection. Here we explored the possibility of species-selective inhibition of lipoamide dehydrogenase (Lpd), an enzyme central to Mtb's intermediary metabolism and antioxidant defense. High-throughput screening of combinatorial chemical libraries identified triazaspirodimethoxybenzoyls as high-nanomolar inhibitors of Mtb's Lpd that were noncompetitive versus NADH, NAD{sup +}, and lipoamide and >100-fold selective compared to human Lpd. Efficacy required the dimethoxy and dichlorophenyl groups. The structure of an Lpd-inhibitor complex was resolved to 2.42 {angstrom} by X-ray crystallography, revealing that the inhibitor occupied a pocket adjacent to the Lpd NADH/NAD{sup +} binding site. The inhibitor did not overlap with the adenosine moiety of NADH/NAD{sup +} but did overlap with positions predicted to bind the nicotinamide rings in NADH and NAD{sup +} complexes. The dimethoxy ring occupied a deep pocket adjacent to the FAD flavin ring where it would block coordination of the NADH nicotinamide ring, while the dichlorophenyl group occupied a more exposed pocket predicted to coordinate the NAD{sup +} nicotinamide. Several residues that are not conserved between the bacterial enzyme and its human homologue were predicted to contribute both to inhibitor binding and to species selectivity, as confirmed for three residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus, nonconservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.

  7. Potent, selective spiropyrrolidine pyrimidinetrione inhibitors of MMP-13.

    PubMed

    Freeman-Cook, Kevin D; Reiter, Lawrence A; Noe, Mark C; Antipas, Amy S; Danley, Dennis E; Datta, Kaushik; Downs, James T; Eisenbeis, Shane; Eskra, James D; Garmene, David J; Greer, Elaine M; Griffiths, Richard J; Guzman, Roberto; Hardink, Joel R; Janat, Fouad; Jones, Christopher S; Martinelli, Gary J; Mitchell, Peter G; Laird, Ellen R; Liras, Jennifer L; Lopresti-Morrow, Lori L; Pandit, Jayvardhan; Reilly, Usa D; Robertson, Donald; Vaughn-Bowser, Marcie L; Wolf-Gouviea, Lilli A; Yocum, Sue A

    2007-12-01

    Explorations in the pyrimidinetrione series of MMP-13 inhibitors led to the discovery of a series of spiro-fused compounds that are potent and selective inhibitors of MMP-13. While other spiro-fused motifs are hydrolytically unstable, presumably due to electronic destabilization of the pyrimidinetrione ring, the spiropyrrolidine series does not share this liability. Greater than 100-fold selectivity versus other MMP family members was achieved by incorporation of an extended aryl-heteroaryl P1'group. When dosed as the sodium salt, these compounds displayed excellent oral absorption and pharmacokinetic properties. Despite the selectivity, a representative of this series produced fibroplasia in a 14 day rat study. PMID:17935984

  8. Design and Synthesis of Potent, Selective Inhibitors of Matriptase

    PubMed Central

    2012-01-01

    Matriptase is a member of the type II transmembrane serine protease family. Several studies have reported deregulated matriptase expression in several types of epithelial cancers, suggesting that matriptase constitutes a potential target for cancer therapy. We report herein a new series of slow, tight-binding inhibitors of matriptase, which mimic the P1–P4 substrate recognition sequence of the enzyme. Preliminary structure–activity relationships indicate that this benzothiazole-containing RQAR-peptidomimetic is a very potent inhibitor and possesses a good selectivity for matriptase versus other serine proteases. A molecular model was generated to elucidate the key contacts between inhibitor 1 and matriptase. PMID:24900505

  9. Discovery of a Potent And Selective Aurora Kinase Inhibitor

    SciTech Connect

    Oslob, J.D.; Romanowski, M.J.; Allen, D.A.; Baskaran, S.; Bui, M.; Elling, R.A.; Flanagan, W.M.; Fung, A.D.; Hanan, E.J.; Harris, S.; Heumann, S.A.; Hoch, U.; Jacobs, J.W.; Lam, J.; Lawrence, C.E.; McDowell, R.S.; Nannini, M.A.; Shen, W.; Silverman, J.A.; Sopko, M.M.; Tangonan, B.T.

    2009-05-21

    This communication describes the discovery of a novel series of Aurora kinase inhibitors. Key SAR and critical binding elements are discussed. Some of the more advanced analogues potently inhibit cellular proliferation and induce phenotypes consistent with Aurora kinase inhibition. In particular, compound 21 (SNS-314) is a potent and selective Aurora kinase inhibitor that exhibits significant activity in pre-clinical in vivo tumor models.

  10. The fatty acid amide hydrolase inhibitor PF-3845 promotes neuronal survival, attenuates inflammation and improves functional recovery in mice with traumatic brain injury

    PubMed Central

    Tchantchou, Flaubert; Tucker, Laura B.; Fu, Amanda H.; Bluett, Rebecca J.; McCabe, Joseph T.; Patel, Sachin; Zhang, Yumin

    2015-01-01

    Traumatic brain injury (TBI) is the leading cause of death in young adults in the United States, but there is still no effective agent for treatment. N-arachidonoylethanolamine (anandamide, AEA) is a major endocannabinoid in the brain. Its increase after brain injury is believed to be protective. However, the compensatory role of AEA is transient due to its rapid hydrolysis by the fatty acid amide hydrolase (FAAH). Thus, inhibition of FAAH can boost the endogenous levels of AEA and prolong its protective effect. Using a TBI mouse model, we found that post-injury chronic treatment with PF3845, a selective and potent FAAH inhibitor, reversed TBI-induced impairments in fine motor movement, hippocampus dependent working memory and anxiety-like behavior. Treatment with PF3845 inactivated FAAH activity and enhanced the AEA levels in the brain. It reduced neurodegeneration in the dentate gyrus, and up-regulated the expression of Bcl-2 and Hsp70/72 in both cortex and hippocampus. PF3845 also suppressed the increased production of amyloid precursor protein, prevented dendritic loss and restored the levels of synaptophysin in the ipsilateral dentate gyrus. Furthermore, PF3845 suppressed the expression of inducible nitric oxide synthase and cyclooxygenase-2 and enhanced the expression of arginase-1 post-TBI, suggesting a shift of microglia/macrophages from M1 to M2 phenotype. The effects of PF3845 on TBI-induced behavioral deficits and neurodegeneration were mediated by activation of cannabinoid type 1 and 2 receptors and might be attributable to the phosphorylation of ERK1/2 and AKT. These results suggest that selective inhibition of FAAH is likely to be beneficial for TBI treatment. PMID:24937045

  11. A Selective Cyclic Peptidic Human SIRT5 Inhibitor.

    PubMed

    Liu, Jiajia; Huang, Yajun; Zheng, Weiping

    2016-01-01

    In the current study, we discovered that a side chain-to-side chain cyclic pentapeptide harboring a central N(ε)-carboxyethyl-thiocarbamoyl-lysine residue behaved as a strong and selective (versus human SIRT1/2/3/6) inhibitor against human SIRT5-catalyzed deacylation reaction. This compound was also found to be proteolytically much more stable than its linear counterpart. This compound could be a valuable lead for developing stronger, selective, metabolically stable, and cell permeable human SIRT5 inhibitors. PMID:27626398

  12. Structure–Activity Relationships of α-Keto Oxazole Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Hardouin, Christophe; Kelso, Michael J.; Romero, F. Anthony; Rayl, Thomas J.; Leung, Donmienne; Hwang, Inkyu; Cravatt, Benjamin F.; Boger, Dale L.

    2008-01-01

    A systematic study of the structure–activity relationships (SAR) of 2b (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the C2 acyl side chain. A series of aryl replacements or substituents for the terminal phenyl group provided effective inhibitors (e.g., 5c, aryl = 1-napthyl, Ki = 2.6 nM) with 5hh (aryl = 3-Cl-Ph, Ki = 900 pM) being 5-fold more potent than 2b. Conformationally-restricted C2 side chains were examined and many provided exceptionally potent inhibitors of which 11j (ethylbiphenyl side chain) was established to be a 750 pM inhibitor. A systematic series of heteroatoms (O, NMe, S), electron-withdrawing groups (SO, SO2), and amides positioned within and hydroxyl substitutions on the linking side chain were investigated which typically led to a loss in potency. The most tolerant positions provided effective inhibitors (12p, 6-position S, Ki = 3 nM or 13d, 2-position OH, Ki = 8 nM) comparable in potency to 2b. Proteomic-wide screening of selected inhibitors from the systematic series of >100 candidates prepared revealed that they are selective for FAAH over all other mammalian serine proteases. PMID:17559203

  13. Uncovering Molecular Bases Underlying Bone Morphogenetic Protein Receptor Inhibitor Selectivity

    PubMed Central

    Alsamarah, Abdelaziz; LaCuran, Alecander E.; Oelschlaeger, Peter; Hao, Jijun; Luo, Yun

    2015-01-01

    Abnormal alteration of bone morphogenetic protein (BMP) signaling is implicated in many types of diseases including cancer and heterotopic ossifications. Hence, small molecules targeting BMP type I receptors (BMPRI) to interrupt BMP signaling are believed to be an effective approach to treat these diseases. However, lack of understanding of the molecular determinants responsible for the binding selectivity of current BMP inhibitors has been a big hindrance to the development of BMP inhibitors for clinical use. To address this issue, we carried out in silico experiments to test whether computational methods can reproduce and explain the high selectivity of a small molecule BMP inhibitor DMH1 on BMPRI kinase ALK2 vs. the closely related TGF-β type I receptor kinase ALK5 and vascular endothelial growth factor receptor type 2 (VEGFR2) tyrosine kinase. We found that, while the rigid docking method used here gave nearly identical binding affinity scores among the three kinases; free energy perturbation coupled with Hamiltonian replica-exchange molecular dynamics (FEP/H-REMD) simulations reproduced the absolute binding free energies in excellent agreement with experimental data. Furthermore, the binding poses identified by FEP/H-REMD led to a quantitative analysis of physical/chemical determinants governing DMH1 selectivity. The current work illustrates that small changes in the binding site residue type (e.g. pre-hinge region in ALK2 vs. ALK5) or side chain orientation (e.g. Tyr219 in caALK2 vs. wtALK2), as well as a subtle structural modification on the ligand (e.g. DMH1 vs. LDN193189) will cause distinct binding profiles and selectivity among BMP inhibitors. Therefore, the current computational approach represents a new way of investigating BMP inhibitors. Our results provide critical information for designing exclusively selective BMP inhibitors for the development of effective pharmacotherapy for diseases caused by aberrant BMP signaling. PMID:26133550

  14. Cardiovascular hazard of selective COX-2 inhibitors: myth or reality?

    PubMed

    Chiolero, Arnaud; Maillard, Marc P; Burnier, Michel

    2002-05-01

    Since 1998, two selective inhibitors of COX-2 have been approved in many countries for the treatment of rheumatoid arthritis, osteoarthritis and acute pain. These new drugs have a significantly reduced gastrointestinal toxicity when compared with non-selective COX inhibitors. However, the results of two large clinical trials conducted in patients with osteoarthritis and rheumatoid arthritis have recently raised some concerns regarding the cardiovascular safety of these new drugs. The purpose of this paper is to review the potential mechanisms whereby selective COX-2 inhibitors could increase the cardiovascular risk of patients and to analyse the data indicating that this clinical risk indeed exists. The authors' analysis shows that even though there are pathophysiological mechanisms which could explain why selective COX-2 inhibition might increase the cardiovascular risk in patients, the actual level of evidence demonstrating that the risk is indeed increased is weak. Because of the importance of the issue, additional studies must be conducted with this class of agents. Meanwhile, it is crucial to emphasise that neither selective COX-2 inhibitors nor conventional NSAIDs replace aspirin in patients with a high cardiovascular risk. PMID:12904159

  15. Discovery of Potent and Selective RSK Inhibitors as Biological Probes.

    PubMed

    Jain, Rama; Mathur, Michelle; Lan, Jiong; Costales, Abran; Atallah, Gordana; Ramurthy, Savithri; Subramanian, Sharadha; Setti, Lina; Feucht, Paul; Warne, Bob; Doyle, Laura; Basham, Stephen; Jefferson, Anne B; Lindvall, Mika; Appleton, Brent A; Shafer, Cynthia M

    2015-09-10

    While the p90 ribosomal S6 kinase (RSK) family has been implicated in multiple tumor cell functions, the full understanding of this kinase family has been restricted by the lack of highly selective inhibitors. A bis-phenol pyrazole was identified from high-throughput screening as an inhibitor of the N-terminal kinase of RSK2. Structure-based drug design using crystallography, conformational analysis, and scaffold morphing resulted in highly optimized difluorophenol pyridine inhibitors of the RSK kinase family as demonstrated cellularly by the inhibition of YB1 phosphorylation. These compounds provide for the first time in vitro tools with an improved selectivity and potency profile to examine the importance of RSK signaling in cancer cells and to fully evaluate RSK as a therapeutic target. PMID:26270416

  16. At Long Last Potent and Selective KDM5 Inhibitors.

    PubMed

    Rotili, Dante; Mattevi, Andrea

    2016-07-21

    Histone lysine demethylase 5 enzymes (KDM5s) have recently been proposed as crucial oncogenic drivers. In this issue of Cell Chemical Biology, Horton et al. (2016) describe results of an extensive structural analysis that reveals how distinct inhibitor chemotypes bind KDM5 and suggest avenues for improving KDM5 inhibitory potency and selectivity. PMID:27447042

  17. Novel selective inhibitors of aminopeptidases that generate antigenic peptides.

    PubMed

    Papakyriakou, Athanasios; Zervoudi, Efthalia; Theodorakis, Emmanuel A; Saveanu, Loredana; Stratikos, Efstratios; Vourloumis, Dionisios

    2013-09-01

    Endoplasmic reticulum aminopeptidases, ERAP1 and ERAP2, as well as Insulin regulated aminopeptidase (IRAP) play key roles in antigen processing, and have recently emerged as biologically important targets for manipulation of antigen presentation. Taking advantage of the available structural and substrate-selectivity data for these enzymes, we have rationally designed a new series of inhibitors that display low micromolar activity. The selectivity profile for these three highly homologous aminopeptidases provides a promising avenue for modulating intracellular antigen processing. PMID:23916253

  18. Full Inhibition of Spinal FAAH Leads to TRPV1-Mediated Analgesic Effects in Neuropathic Rats and Possible Lipoxygenase-Mediated Remodeling of Anandamide Metabolism

    PubMed Central

    Starowicz, Katarzyna; Makuch, Wioletta; Korostynski, Michal; Malek, Natalia; Slezak, Michal; Zychowska, Magdalena; Petrosino, Stefania; De Petrocellis, Luciano; Cristino, Luigia; Przewlocka, Barbara; Di Marzo, Vincenzo

    2013-01-01

    Neuropathic pain elevates spinal anandamide (AEA) levels in a way further increased when URB597, an inhibitor of AEA hydrolysis by fatty acid amide hydrolase (FAAH), is injected intrathecally. Spinal AEA reduces neuropathic pain by acting at both cannabinoid CB1 receptors and transient receptor potential vanilloid-1 (TRPV1) channels. Yet, intrathecal URB597 is only partially effective at counteracting neuropathic pain. We investigated the effect of high doses of intrathecal URB597 on allodynia and hyperalgesia in rats with chronic constriction injury (CCI) of the sciatic nerve. Among those tested, the 200 µg/rat dose of URB597 was the only one that elevated the levels of the FAAH non-endocannabinoid and anti-inflammatory substrates, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), and of the endocannabinoid FAAH substrate, 2-arachidonoylglycerol, and fully inhibited thermal and tactile nociception, although in a manner blocked almost uniquely by TRPV1 antagonism. Surprisingly, this dose of URB597 decreased spinal AEA levels. RT-qPCR and western blot analyses demonstrated altered spinal expression of lipoxygenases (LOX), and baicalein, an inhibitor of 12/15-LOX, significantly reduced URB597 analgesic effects, suggesting the occurrence of alternative pathways of AEA metabolism. Using immunofluorescence techniques, FAAH, 15-LOX and TRPV1 were found to co-localize in dorsal spinal horn neurons of CCI rats. Finally, 15-hydroxy-AEA, a 15-LOX derivative of AEA, potently and efficaciously activated the rat recombinant TRPV1 channel. We suggest that intrathecally injected URB597 at full analgesic efficacy unmasks a secondary route of AEA metabolism via 15-LOX with possible formation of 15-hydroxy-AEA, which, together with OEA and PEA, may contribute at producing TRPV1-mediated analgesia in CCI rats. PMID:23573230

  19. Loratadine analogues as MAGL inhibitors.

    PubMed

    Patel, Jayendra Z; Ahenkorah, Stephen; Vaara, Miia; Staszewski, Marek; Adams, Yahaya; Laitinen, Tuomo; Navia-Paldanius, Dina; Parkkari, Teija; Savinainen, Juha R; Walczyński, Krzysztof; Laitinen, Jarmo T; Nevalainen, Tapio J

    2015-04-01

    Compound 12a (JZP-361) acted as a potent and reversible inhibitor of human recombinant MAGL (hMAGL, IC50=46 nM), and was found to have almost 150-fold higher selectivity over human recombinant fatty acid amide hydrolase (hFAAH, IC50=7.24 μM) and 35-fold higher selectivity over human α/β-hydrolase-6 (hABHD6, IC50=1.79 μM). Additionally, compound 12a retained H1 antagonistic affinity (pA2=6.81) but did not show cannabinoid receptor activity, when tested at concentrations ⩽ 10 μM. Hence, compound 12a represents a novel dual-acting pharmacological tool possessing both MAGL-inhibitory and antihistaminergic activities. PMID:25752982

  20. Metabolism of a highly selective gelatinase inhibitor generates active metabolite.

    PubMed

    Lee, Mijoon; Villegas-Estrada, Adriel; Celenza, Giuseppe; Boggess, Bill; Toth, Marta; Kreitinger, Gloria; Forbes, Christopher; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

    2007-11-01

    (4-Phenoxyphenylsulfonyl)methylthiirane (inhibitor 1) is a highly selective inhibitor of gelatinases (matrix metalloproteinases 2 and 9), which is showing considerable promise in animal models for cancer and stroke. Despite demonstrated potent, selective, and effective inhibition of gelatinases both in vitro and in vivo, the compound is rapidly metabolized, implying that the likely activity in vivo is due to a metabolite rather than the compound itself. To this end, metabolism of inhibitor 1 was investigated in in vitro systems. Four metabolites were identified by LC/MS-MS and the structures of three of them were further validated by comparison with authentic synthetic samples. One metabolite, 4-(4-thiiranylmethanesulfonylphenoxy)phenol (compound 21), was generated by hydroxylation of the terminal phenyl group of 1. This compound was investigated in kinetics of inhibition of several matrix metalloproteinases. This metabolite was a more potent slow-binding inhibitor of gelatinases (matrix metalloproteinase-2 and matrix metalloproteinase-9) than the parent compound 1, but it also served as a slow-binding inhibitor of matrix metalloproteinase-14, the upstream activator of matrix metalloproteinase-2. PMID:17927722

  1. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials

    PubMed Central

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

  2. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials.

    PubMed

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

  3. Treating cancer with selective CDK4/6 inhibitors.

    PubMed

    O'Leary, Ben; Finn, Richard S; Turner, Nicholas C

    2016-07-01

    Uncontrolled cellular proliferation, mediated by dysregulation of the cell-cycle machinery and activation of cyclin-dependent kinases (CDKs) to promote cell-cycle progression, lies at the heart of cancer as a pathological process. Clinical implementation of first-generation, nonselective CDK inhibitors, designed to inhibit this proliferation, was originally hampered by the high risk of toxicity and lack of efficacy noted with these agents. The emergence of a new generation of selective CDK4/6 inhibitors, including ribociclib, abemaciclib and palbociclib, has enabled tumour types in which CDK4/6 has a pivotal role in the G1-to-S-phase cell-cycle transition to be targeted with improved effectiveness, and fewer adverse effects. Results of pivotal phase III trials investigating palbociclib in patients with advanced-stage oestrogen receptor (ER)-positive breast cancer have demonstrated a substantial improvement in progression-free survival, with a well-tolerated toxicity profile. Mechanisms of acquired resistance to CDK4/6 inhibitors are beginning to emerge that, although unwelcome, might enable rational post-CDK4/6 inhibitor therapeutic strategies to be identified. Extending the use of CDK4/6 inhibitors beyond ER-positive breast cancer is challenging, and will likely require biomarkers that are predictive of a response, and the use of combination therapies in order to optimize CDK4/6 targeting. PMID:27030077

  4. Polyoxometalates--potent and selective ecto-nucleotidase inhibitors.

    PubMed

    Lee, Sang-Yong; Fiene, Amelie; Li, Wenjin; Hanck, Theodor; Brylev, Konstantin A; Fedorov, Vladimir E; Lecka, Joanna; Haider, Ali; Pietzsch, Hans-Jürgen; Zimmermann, Herbert; Sévigny, Jean; Kortz, Ulrich; Stephan, Holger; Müller, Christa E

    2015-01-15

    Polyoxometalates (POMs) are inorganic cluster metal complexes that possess versatile biological activities, including antibacterial, anticancer, antidiabetic, and antiviral effects. Their mechanisms of action at the molecular level are largely unknown. However, it has been suggested that the inhibition of several enzyme families (e.g., phosphatases, protein kinases or ecto-nucleotidases) by POMs may contribute to their pharmacological properties. Ecto-nucleotidases are cell membrane-bound or secreted glycoproteins involved in the hydrolysis of extracellular nucleotides thereby regulating purinergic (and pyrimidinergic) signaling. They comprise four distinct families: ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs), alkaline phosphatases (APs) and ecto-5'-nucleotidase (eN). In the present study, we evaluated the inhibitory potency of a series of polyoxometalates as well as chalcogenide hexarhenium cluster complexes at a broad range of ecto-nucleotidases. [Co4(H2O)2(PW9O34)2](10-) (5, PSB-POM142) was discovered to be the most potent inhibitor of human NTPDase1 described so far (Ki: 3.88 nM). Other investigated POMs selectively inhibited human NPP1, [TiW11CoO40](8-) (4, PSB-POM141, Ki: 1.46 nM) and [NaSb9W21O86](18-) (6, PSB-POM143, Ki: 4.98 nM) representing the most potent and selective human NPP1 inhibitors described to date. [NaP5W30O110](14-) (8, PSB-POM144) strongly inhibited NTPDase1-3 and NPP1 and may therefore be used as a pan-inhibitor to block ATP hydrolysis. The polyoxoanionic compounds displayed a non-competitive mechanism of inhibition of NPPs and eN, but appeared to be competitive inhibitors of TNAP. Future in vivo studies with selected inhibitors identified in the current study are warranted. PMID:25449596

  5. New Frontiers in Selective Human MAO-B Inhibitors.

    PubMed

    Carradori, Simone; Silvestri, Romano

    2015-09-10

    Accumulating evidence shows a relationship between the human MAO-B (hMAO-B) enzyme and neuropsychiatric/degenerative disorder, personality traits, type II alcoholism, borderline personality disorders, aggressiveness and violence in crime, obsessive-compulsive disorder, depression, suicide, schizophrenia, anorexia nervosa, migraine, dementia, and PD. Thus, MAO-B represents an attractive target for the treatment of a number of human diseases. The discovery, development, and therapeutic use of drugs that inhibit MAO-B are major challenges for future therapy. Various compounds and drugs that selectively target this isoform have been discovered recently. These agents are synthetic compounds or natural products and their analogues, including chalcones, pyrazoles, chromones, coumarins, xanthines, isatin derivatives, thiazolidindiones, (thiazol-2-yl)hydrazones, and analogues of marketed drugs. Despite considerable efforts in understanding the binding interaction with specific substrates or inhibitors, structural information available for the rational design of new hMAO-B inhibitors remains unsatisfactory. Therefore, the quest for novel, potent, and selective hMAO-B inhibitors remains of high interest. PMID:25915162

  6. A highly selective telomerase inhibitor limiting human cancer cell proliferation

    PubMed Central

    Damm, Klaus; Hemmann, Ulrike; Garin-Chesa, Pilar; Hauel, Norbert; Kauffmann, Iris; Priepke, Henning; Niestroj, Claudia; Daiber, Christine; Enenkel, Barbara; Guilliard, Bernd; Lauritsch, Ines; Müller, Elfriede; Pascolo, Emanuelle; Sauter, Gabriele; Pantic, Milena; Martens, Uwe M.; Wenz, Christian; Lingner, Joachim; Kraut, Norbert; Rettig, Wolfgang J.; Schnapp, Andreas

    2001-01-01

    Telomerase, the ribonucleoprotein enzyme maintaining the telomeres of eukaryotic chromosomes, is active in most human cancers and in germline cells but, with few exceptions, not in normal human somatic tissues. Telomere maintenance is essential to the replicative potential of malignant cells and the inhibition of telomerase can lead to telomere shortening and cessation of unrestrained proliferation. We describe novel chemical compounds which selectively inhibit telomerase in vitro and in vivo. Treatment of cancer cells with these inhibitors leads to progressive telomere shortening, with no acute cytotoxicity, but a proliferation arrest after a characteristic lag period with hallmarks of senescence, including morphological, mitotic and chromosomal aberrations and altered patterns of gene expression. Telomerase inhibition and telomere shortening also result in a marked reduction of the tumorigenic potential of drug-treated tumour cells in a mouse xenograft model. This model was also used to demonstrate in vivo efficacy with no adverse side effects and uncomplicated oral administration of the inhibitor. These findings indicate that potent and selective, non-nucleosidic telomerase inhibitors can be designed as novel cancer treatment modalities. PMID:11742973

  7. Arachidonate 12-lipoxygenases with reference to their selective inhibitors

    SciTech Connect

    Yamamoto, Shozo . E-mail: yamamosh@kyoto-wu.ac.jp; Katsukawa, Michiko; Nakano, Ayumi; Hiraki, Emi; Nishimura, Kohji; Jisaka, Mitsuo; Yokota, Kazushige; Ueda, Natsuo

    2005-12-09

    Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxy eicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-geotechnical gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC{sub 5} of 0.14 {mu}M. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclo oxygenases-1 and -2.

  8. Potent and selective nonpeptidic inhibitors of procollagen C-proteinase.

    PubMed

    Fish, Paul V; Allan, Gillian A; Bailey, Simon; Blagg, Julian; Butt, Richard; Collis, Michael G; Greiling, Doris; James, Kim; Kendall, Jackie; McElroy, Andrew; McCleverty, Dawn; Reed, Charlotte; Webster, Robert; Whitlock, Gavin A

    2007-07-26

    6-Cyclohexyl-N-hydroxy-3-(1,2,4-oxadiazol-5-yl)hexanamides were previously disclosed as inhibitors of procollagen C-proteinase (PCP) culminating in the identification of amide 1. Our objective was to discover a second inhibitor that would have improved affinity for PCP and to optimize properties for transepidermal delivery (TED) to intact skin. Further investigation of this template identified a number of potent PCP inhibitors (IC50 values of 2-6 nM) with improved TED flux. Sulfonamide 56 had excellent PCP enzyme activity when measured with a peptide substrate (Ki 8.7 nM) or with the endogenous substrate procollagen (IC50 3.4 nM) and demonstrates excellent selectivity over MMPs involved in wound healing (>10 000-fold). In the fibroplasia model, 56 inhibited deposition of insoluble collagen by 76 +/- 2% at 10 microM and was very effective at penetrating human skin in vitro with a TED flux of 1.5 microg/cm2/h, which compares favorably with values for agents that are known to penetrate skin well in vivo. Based on this profile, 56 (UK-421,045) was selected as a candidate for further preclinical evaluation as a topically applied, dermal anti-scarring agent. PMID:17591762

  9. KIDFamMap: a database of kinase-inhibitor-disease family maps for kinase inhibitor selectivity and binding mechanisms.

    PubMed

    Chiu, Yi-Yuan; Lin, Chih-Ta; Huang, Jhang-Wei; Hsu, Kai-Cheng; Tseng, Jen-Hu; You, Syuan-Ren; Yang, Jinn-Moon

    2013-01-01

    Kinases play central roles in signaling pathways and are promising therapeutic targets for many diseases. Designing selective kinase inhibitors is an emergent and challenging task, because kinases share an evolutionary conserved ATP-binding site. KIDFamMap (http://gemdock.life.nctu.edu.tw/KIDFamMap/) is the first database to explore kinase-inhibitor families (KIFs) and kinase-inhibitor-disease (KID) relationships for kinase inhibitor selectivity and mechanisms. This database includes 1208 KIFs, 962 KIDs, 55 603 kinase-inhibitor interactions (KIIs), 35 788 kinase inhibitors, 399 human protein kinases, 339 diseases and 638 disease allelic variants. Here, a KIF can be defined as follows: (i) the kinases in the KIF with significant sequence similarity, (ii) the inhibitors in the KIF with significant topology similarity and (iii) the KIIs in the KIF with significant interaction similarity. The KIIs within a KIF are often conserved on some consensus KIDFamMap anchors, which represent conserved interactions between the kinase subsites and consensus moieties of their inhibitors. Our experimental results reveal that the members of a KIF often possess similar inhibition profiles. The KIDFamMap anchors can reflect kinase conformations types, kinase functions and kinase inhibitor selectivity. We believe that KIDFamMap provides biological insights into kinase inhibitor selectivity and binding mechanisms. PMID:23193279

  10. KIDFamMap: a database of kinase-inhibitor-disease family maps for kinase inhibitor selectivity and binding mechanisms

    PubMed Central

    Chiu, Yi-Yuan; Lin, Chih-Ta; Huang, Jhang-Wei; Hsu, Kai-Cheng; Tseng, Jen-Hu; You, Syuan-Ren; Yang, Jinn-Moon

    2013-01-01

    Kinases play central roles in signaling pathways and are promising therapeutic targets for many diseases. Designing selective kinase inhibitors is an emergent and challenging task, because kinases share an evolutionary conserved ATP-binding site. KIDFamMap (http://gemdock.life.nctu.edu.tw/KIDFamMap/) is the first database to explore kinase-inhibitor families (KIFs) and kinase-inhibitor-disease (KID) relationships for kinase inhibitor selectivity and mechanisms. This database includes 1208 KIFs, 962 KIDs, 55 603 kinase-inhibitor interactions (KIIs), 35 788 kinase inhibitors, 399 human protein kinases, 339 diseases and 638 disease allelic variants. Here, a KIF can be defined as follows: (i) the kinases in the KIF with significant sequence similarity, (ii) the inhibitors in the KIF with significant topology similarity and (iii) the KIIs in the KIF with significant interaction similarity. The KIIs within a KIF are often conserved on some consensus KIDFamMap anchors, which represent conserved interactions between the kinase subsites and consensus moieties of their inhibitors. Our experimental results reveal that the members of a KIF often possess similar inhibition profiles. The KIDFamMap anchors can reflect kinase conformations types, kinase functions and kinase inhibitor selectivity. We believe that KIDFamMap provides biological insights into kinase inhibitor selectivity and binding mechanisms. PMID:23193279

  11. Novel JAK1-selective benzimidazole inhibitors with enhanced membrane permeability.

    PubMed

    Kim, Hyungmi; Kim, Mi Kyoung; Choo, Hyunah; Chong, Youhoon

    2016-07-15

    The previously identified Janus kinase 1 (JAK1)-selective inhibitor, 1-(2-aminoethyl)-2-(piperidin-4-yl)-1H-benzo[d]imidazole-5-carboxamide (2), suffered from low cell permeability, which resulted in poor pharmacokinetic properties. In this study, by introducing less polar hydrogen bond donors at N(1) (a hydroxyalkyl or a methylaminoalkyl group) and C2 (a cyclohexanol group) positions, a series of novel benzimidazole derivatives were prepared, which exhibited selective JAK1 inhibitory activity (IC50 against JAK1=0.08-0.15μM; JAK1-selectivity=26-40 fold vs JAK2, 12-23 fold vs JAK3, and 38-54 fold vs Tyk2) along with significantly increased lipophilicity (3.3-15.8 times) as well as membrane permeability (6.3-12 times). PMID:27261178

  12. The Selectivity of CK2 Inhibitor Quinalizarin: A Reevaluation

    PubMed Central

    Cozza, Giorgio; Venerando, Andrea; Sarno, Stefania; Pinna, Lorenzo A.

    2015-01-01

    Many polyphenolic compounds have been reported to inhibit protein kinases, with special reference to CK2, a pleiotropic serine/threonine kinase, implicated in neoplasia, neurodegenerative disease, and viral infections. In general however these compounds are not endowed with stringent selectivity. Among them quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) turned out to be particularly potent (Ki = 0.058 μM) and quite selective as judged by profiling it on a small panel of 70 protein kinases. Here, by profiling quinalizarin on a larger panel of 140 kinases we reach the conclusion that quinalizarin is one of the most selective inhibitors of CK2, superior to the first-in-class CK2 inhibitor, CX-4945, now in clinical trials for the treatment of cancer. Moreover here we show that quinalizarin is able to discriminate between the isolated CK2 catalytic subunit (CK2α) and CK2 holoenzyme (CK2α2β2), consistent with in silico and in vitro analyses. PMID:26558278

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

    PubMed

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

    2008-10-15

    Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in the clinic. Herein we describe the optimization of a series of ketone small molecule HDAC inhibitors leading to potent and selective class I HDAC inhibitors with good dog PK. PMID:18809328

  14. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2.

    PubMed

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-07-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  15. Discovery of a Highly Selective STK16 Kinase Inhibitor.

    PubMed

    Liu, Feiyang; Wang, Jinhua; Yang, Xingxing; Li, Binhua; Wu, Hong; Qi, Shuang; Chen, Cheng; Liu, Xiaochuan; Yu, Kailin; Wang, Wenchao; Zhao, Zheng; Wang, Aoli; Chen, Yongfei; Wang, Li; Gray, Nathanael S; Liu, Jing; Zhang, Xin; Liu, Qingsong

    2016-06-17

    STK16, a serine/threonine protein kinase, is ubiquitously expressed and is conserved among all eukaryotes. STK16 has been implicated to function in a variety of cellular processes such as VEGF and cargo secretion, but the pathways through which these effects are mediated remain to be elucidated. Through screening of our focused library of kinase inhibitors, we discovered a highly selective ATP competitive inhibitor, STK16-IN-1, which exhibits potent inhibitory activity against STK16 kinase (IC50: 0.295 μM) with excellent selectivity across the kinome as assessed using the KinomeScan profiling assay (S score (1) = 0.0). In MCF-7 cells, treatment with STK16-IN-1 results in a reduction in cell number and accumulation of binucleated cells, which can be recapitulated by RNAi knockdown of STK16. Co-treatment of STK16-IN-1 with chemotherapeutics such as cisplatin, doxorubicin, colchicine, and paclitaxel results in a slight potentiation of the antiproliferative effects of the chemotherapeutics. STK16-IN-1 provides a useful tool compound for further elucidating the biological functions of STK16. PMID:27082499

  16. Benzothiophene inhibitors of MK2. Part 2: Improvements in kinase selectivity and cell potency

    SciTech Connect

    Anderson, David R.; Meyers, Marvin J.; Kurumbail, Ravi G.; Caspers, Nicole; Poda, Gennadiy I.; Long, Scott A.; Pierce, Betsy S.; Mahoney, Matthew W.; Mourey, Robert J.; Parikh, Mihir D.; Pfizer

    2010-10-01

    Optimization of kinase selectivity for a set of benzothiophene MK2 inhibitors provided analogs with potencies of less than 500 nM in a cell based assay. The selectivity of the inhibitors can be rationalized by examination of X-ray crystal structures of inhibitors bound to MK2.

  17. Benzimidazole Derivatives as Potent JAK1-Selective Inhibitors.

    PubMed

    Kim, Mi Kyoung; Shin, Heerim; Park, Kwang-su; Kim, Hyungmi; Park, Jiseon; Kim, Kangjeon; Nam, Joonwoo; Choo, Hyunah; Chong, Youhoon

    2015-09-24

    The Janus kinase (JAK) family comprises four members (JAK1, JAK2, JAK3, and Tyk2) that play a key role in mediating cytokine receptor signaling. JAK inhibition thus modulates cytokine-mediated effects. In particular, selective inhibition of JAK1 or JAK3 may provide an efficient therapeutic agent for the treatment of inflammatory diseases, with minimized side effects. In this study, as part of our continued efforts to develop a selective JAK1 inhibitor, a series of 1,2-disubstituted benzimidazole-5-carboxamide derivatives was prepared and their inhibitory activities against all four JAK isozymes were evaluated. A clear structure-activity relationship was observed with respect to JAK1 selectivity; this highlighted the importance of hydrogen bond donors at both N(1) and R2 positions located within a specific distance from the benzimidazole core. One of the synthesized compounds, 1-(2-aminoethyl)-2-(piperidin-4-yl)-1H-benzo[d]imidazole-5-carboxamide (5c), showed remarkable JAK1 selectivity (63-fold vs JAK2, 25-fold vs JAK3, and 74-fold vs Tyk2). Molecular docking revealed that the 2-aminoethyl and piperidin-4-yl substituents of 5c function as probes to differentiate the ATP-binding site of JAK1 from that of JAK2, resulting in preferential JAK1 binding. A kinase panel assay confirmed the JAK1 selectivity of 5c, which showed no appreciable inhibitory activity against 26 other protein kinases at 10 μM. PMID:26351728

  18. Identification of selective enzyme inhibitors by fragment library screening.

    PubMed

    Gao, Geng; Liu, Xuying; Pavlovsky, Alexander; Viola, Ronald E

    2010-10-01

    The microbial threat to human health is growing due to the dramatic increase in the number of multidrug-resistant organisms. The decline in effective antibiotics available to treat these growing threats has provided greater urgency to the search for new antibiotics. Clearly, new approaches must be developed against novel targets to control these resistant infectious organisms. The screening of low molecular weight compounds against new protein targets provides an opportunity to identify novel inhibitors as starting points for the development of new antibiotics. Custom fragment libraries have been assembled and screened against 3 representative forms of a key enzyme in an essential microbial biosynthetic pathway. Although each of these aspartate semialdehyde dehydrogenases (ASADHs) catalyzes the same reaction and each shares identical active site functional groups, subtle differences in enzyme structures have led to different binding selectivity among the initial hits from these fragment libraries. Amino acid analogues have been identified that show selectivity for either the gram-negative or gram-positive bacterial enzyme forms. A series of benzophenone analogues selectively inhibit the gram-negative ASADH, whereas some haloacids and substituted aromatic acids have been found to inhibit only the fungal form of ASADH. Each of these low molecular weight compounds possesses high ligand binding efficiency for their target enzyme forms. These results support the goal of designing lead compounds that will selectively target ASADHs from different microbial species. PMID:20855558

  19. Novel Associations between FAAH Genetic Variants and Postoperative Central Opioid related Adverse Effects

    PubMed Central

    Sadhasivam, Senthilkumar; Zhang, Xue; Chidambaran, Vidya; Mavi, Jagroop; Pilipenko, Valentina; Mersha, Tesfaye B.; Meller, Jaroslaw; Kaufman, Kenneth M.; Martin, Lisa J.; McAuliffe, John

    2014-01-01

    Opioid effects are potentiated by cannabinoid agonists including anandamide, an endocannabinoid. Inter-individual variability in responses to opioids is a major clinical problem. Multiple deaths and anoxic brain injuries occur every year in due to opioid induced respiratory depression in surgical patients and drug abusers of opioids and cannabinoids. This study aimed to determine specific associations between genetic variants of fatty acid amide hydrolase (FAAH) and postoperative central opioid adverse effects in children undergoing tonsillectomy. This is a prospective genotype blinded observational study 259 healthy children between 6 and 15 years that received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine were enrolled. Associations between frequent polymorphisms of FAAH and central postoperative opioid adverse effects including, respiratory depression (RD), postoperative nausea and vomiting (PONV) and prolonged stay in Post Anesthesia Recovery Room (PACU) due to RD and PONV were analyzed. Five specific FAAH SNPs had significant associations with more than 2 fold increased risk for refractory PONV (adjusted p<0.0018), and nominal associations (p<0.05) with RD and prolonged PACU stay in white children undergoing tonsillectomy. FAAH SNP, rs324420 is a missense mutation with altered FAAH function and it is linked with other FAAH SNPs associated with PONV and RD in our cohort; association between PONV and rs324420 was confirmed in our extended cohort with additional 66 white children. Specific FAAH polymorphisms are associated with refractory PONV, opioid-related respiratory depression, and prolonged PACU stay due to opioid adverse effects in white children undergoing tonsillectomy. PMID:25558980

  20. Novel associations between FAAH genetic variants and postoperative central opioid-related adverse effects.

    PubMed

    Sadhasivam, S; Zhang, X; Chidambaran, V; Mavi, J; Pilipenko, V; Mersha, T B; Meller, J; Kaufman, K M; Martin, L J; McAuliffe, J

    2015-10-01

    Opioid effects are potentiated by cannabinoid agonists including anandamide, an endocannabinoid. Inter-individual variability in responses to opioids is a major clinical problem. Multiple deaths and anoxic brain injuries occur every year because of opioid-induced respiratory depression (RD) in surgical patients and drug abusers of opioids and cannabinoids. This study aimed to determine specific associations between genetic variants of fatty acid amide hydrolase (FAAH) and postoperative central opioid adverse effects in children undergoing tonsillectomy. This is a prospective genotype-blinded observational study in which 259 healthy children between 6 and 15 years of age who received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine were enrolled. Associations between frequent polymorphisms of FAAH and central postoperative opioid adverse effects including, RD, postoperative nausea and vomiting (PONV) and prolonged stay in Post Anesthesia Recovery Room (postoperative anesthesia care unit, PACU) due to RD and PONV were analyzed. Five specific FAAH single nucleotide polymorphisms (SNPs) had significant associations with more than twofold increased risk for refractory PONV (adjusted P<0.0018), and nominal associations (P<0.05) with RD and prolonged PACU stay in white children undergoing tonsillectomy. The FAAH SNP, rs324420, is a missense mutation with altered FAAH function and it is linked with other FAAH SNPs associated with PONV and RD in our cohort; association between PONV and rs324420 was confirmed in our extended cohort with additional 66 white children. Specific FAAH polymorphisms are associated with refractory PONV, opioid-related RD, and prolonged PACU stay due to opioid adverse effects in white children undergoing tonsillectomy. PMID:25558980

  1. Design and synthesis of novel selective anaplastic lymphoma kinase inhibitors.

    PubMed

    Michellys, Pierre-Yves; Chen, Bei; Jiang, Tao; Jin, Yunho; Lu, Wenshuo; Marsilje, Thomas H; Pei, Wei; Uno, Tetsuo; Zhu, Xuefeng; Wu, Baogen; Nguyen, Truc Ngoc; Bursulaya, Badry; Lee, Christian; Li, Nanxin; Kim, Sungjoon; Tuntland, Tove; Liu, Bo; Sun, Frank; Steffy, Auzon; Hood, Tami

    2016-02-01

    Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase belonging to the insulin receptor superfamily. Expression of ALK in normal human tissues is only found in a subset of neural cells, however it is involved in the genesis of several cancers through genetic aberrations involving translocation of the kinase domain with multiple fusion partners (e.g., NPM-ALK in anaplastic large cell lymphoma ALCL or EML4-ALK in non-small cell lung cancer) or activating mutations in the full-length receptor resulting in ligand-independent constitutive activation (e.g., neuroblastoma). Here we are reporting the discovery of novel and selective anaplastic lymphoma kinase inhibitors from specific modifications of the 2,4-diaminopyridine core present in TAE684 and LDK378. Synthesis, structure activity relationships (SAR), absorption, distribution, metabolism, and excretion (ADME) profile, and in vivo efficacy in a mouse xenograft model of anaplastic large cell lymphoma are described. PMID:26750252

  2. The use of selective serotonin reuptake inhibitors in eating disorders.

    PubMed

    Mayer, L E; Walsh, B T

    1998-01-01

    The introduction of selective serotonin reuptake inhibitors (SSRIs), which are, in general, safer and more easily tolerated than conventional antidepressants, has had a profound effect on the treatment of affective illnesses and obsessive-compulsive disorder (OCD). A number of symptoms associated with eating disorders overlap those of depression and OCD, suggesting a theoretical and practical case for evaluating the SSRIs in the treatment of anorexia nervosa, bulimia nervosa, binge-eating disorder, and obesity. Despite the expectations for SSRIs in the treatment of eating disorders, clinical investigations have yielded mixed results. In this paper, results from clinical studies of SSRIs (with and without concomitant psychotherapy) in the treatment of anorexia and bulimia nervosa, binge eating disorder, and obesity are reviewed, directions for future research are suggested, and practical recommendations for the clinician are provided. PMID:9786308

  3. Depletion of selective serotonin reuptake inhibitors during sewage sludge composting.

    PubMed

    Vasskog, Terje; Bergersen, Ove; Anderssen, Trude; Jensen, Einar; Eggen, Trine

    2009-11-01

    Sewage and sewage sludge is known to contain pharmaceuticals, and since sewage sludge is often used as fertilizer within agriculture, the reduction of the selective serotonin reuptake inhibitors (SSRIs) Citalopram, Sertraline, Paroxetine, Fluvoxamine and Fluoxetine during composting has been investigated. Sewage sludge was spiked with the SSRIs before the composting experiment started, and the concentration of the SSRIs in the sludge during a 21 day composting period was measured by liquid phase microextraction (LPME) and high-performance liquid chromatography-mass spectrometry. All the SSRIs had a significant decrease in concentration during the composting process. The highest reduction rates were measured for Fluoxetine and Paroxetine and the lowest for Citalopram. In addition three out of four known SSRI metabolites were found in all the samples, and two of them showed a significant increase in concentration during the composting period. PMID:19595585

  4. Discovery of a Selective Aurora A Kinase Inhibitor by Virtual Screening.

    PubMed

    Kilchmann, Falco; Marcaida, Maria J; Kotak, Sachin; Schick, Thomas; Boss, Silvan D; Awale, Mahendra; Gönczy, Pierre; Reymond, Jean-Louis

    2016-08-11

    Here we report the discovery of a selective inhibitor of Aurora A, a key regulator of cell division and potential anticancer target. We used the atom category extended ligand overlap score (xLOS), a 3D ligand-based virtual screening method recently developed in our group, to select 437 shape and pharmacophore analogs of reference kinase inhibitors. Biochemical screening uncovered two inhibitor series with scaffolds unprecedented among kinase inhibitors. One of them was successfully optimized by structure-based design to a potent Aurora A inhibitor (IC50 = 2 nM) with very high kinome selectivity for Aurora kinases. This inhibitor locks Aurora A in an inactive conformation and disrupts binding to its activator protein TPX2, which impairs Aurora A localization at the mitotic spindle and induces cell division defects. This phenotype can be rescued by inhibitor-resistant Aurora A mutants. The inhibitor furthermore does not induce Aurora B specific effects in cells. PMID:27391133

  5. Selective Monoacylglycerol Lipase Inhibitors: Antinociceptive versus Cannabimimetic Effects in Mice

    PubMed Central

    Wilkerson, Jenny L.; Mustafa, Mohammed; Abdullah, Rehab; Niphakis, Micah; Wiley, Jenny L.; Cravatt, Benjamin F.; Lichtman, Aron H.

    2015-01-01

    The endogenous cannabinoid 2-arachidonoylglycerol (2-AG) plays an important role in a variety of physiologic processes, but its rapid breakdown by monoacylglycerol lipase (MAGL) results in short-lived actions. Initial MAGL inhibitors were limited by poor selectivity and low potency. In this study, we tested JZL184 [4-nitrophenyl 4-[bis(2H-1,3-benzodioxol-5-yl)(hydroxy)methyl]piperidine-1-carboxylate] and MJN110 [2,5-dioxopyrrolidin-1-yl 4-(bis(4-chlorophenyl)methyl)piperazine-1-carboxylate], MAGL inhibitors that possess increased selectivity and potency, in mouse behavioral assays of neuropathic pain [chronic constriction injury (CCI) of the sciatic nerve], interoceptive cannabimimetic effects (drug-discrimination paradigm), and locomotor activity in an open field test. MJN110 (1.25 and 2.5 mg/kg) and JZL184 (16 and 40 mg/kg) significantly elevated 2-AG and decreased arachidonic acid but did not affect anandamide in whole brains. Both MAGL inhibitors significantly reduced CCI-induced mechanical allodynia with the following potencies [ED50 (95% confidence limit [CL]) values in mg/kg: MJN110 (0.43 [0.30–0.63]) > JZL184 (17.8 [11.6–27.4])] and also substituted for the potent cannabinoid receptor agonist CP55,940 [2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]-5-(2-methyloctan-2-yl)phenol] in the drug-discrimination paradigm [ED50 (95% CL) values in mg/kg: MJN110 (0.84 [0.69–1.02]) > JZL184 (24.9 [14.6–42.5])]; however, these compounds elicited differential effects on locomotor behavior. Similar to cannabinoid 1 (CB1) receptor agonists, JZL184 produced hypomotility, whereas MJN110 increased locomotor behavior and did not produce catalepsy or hypothermia. Although both drugs substituted for CP55,940 in the drug discrimination assay, MJN110 was more potent in reversing allodynia in the CCI model than in producing CP55,940-like effects. Overall, these results suggest that MAGL inhibition may alleviate neuropathic pain, while displaying limited

  6. Formation of prostamides from anandamide in FAAH knockout mice analyzed by HPLC with tandem mass spectrometry.

    PubMed

    Weber, Allan; Ni, Jinsong; Ling, Kah-Hiing John; Acheampong, Andrew; Tang-Liu, Diane D-S; Burk, Robert; Cravatt, Benjamin F; Woodward, David

    2004-04-01

    We investigated the formation of PGF(2alpha) 1-ethanolamide, PGE(2) 1-ethanolamide, and PGD(2) 1-ethanolamide (prostamides F(2alpha), E(2), and D(2), respectively) in liver, lung, kidney, and small intestine after a single intravenous bolus administration of 50 mg/kg of anandamide to normal and fatty acid amide hydrolase knockout (FAAH -/-) male mice. One group of three normal mice was not dosed (naïve) while another group of three normal mice received a bolus intravenous injection of 50 mg/kg of anandamide. Three FAAH -/- mice also received an intravenous injection of 50 mg/kg of anandamide. After 30 min, the lung, liver, kidney, and small intestine were harvested and processed by liquid-liquid extraction. The concentrations of prostamide F(2alpha), prostamide E(2), prostamide D(2), and anandamide were determined by HPLC-tandem mass spectrometry. Prostamide F(2alpha) was detected in tissues in FAAH -/- mice after administration of anandamide. Concentrations of anandamide, prostamide E(2), and prostamide D(2) in liver, kidney, lung, and small intestine were much higher in the anandamide-treated FAAH -/- mice than those of the anandamide-treated control mice. This report demonstrates that prostamides, including prostamide F(2alpha), were formed in vivo from anandamide, potentially by the cyclooxygenase-2 pathway when the competing FAAH pathway is lacking. PMID:14729864

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

    PubMed

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

    2014-01-01

    The activity of cis-cinnamic acid (cis-CA), one of the allelochemicals, in plants is very similar to that of indole-3-acetic acid (IAA), a natural auxin, and thus cis-CA has long been believed to be an analog of auxin. We have reported some structure-activity relationships studies by synthesizing over 250 cis-CA derivatives and estimating their inhibitory activities on root growth inhibition in lettuce. In this study, the compounds that showed low- or no-activity on root growth inhibition were recruited as candidates suppressors against cis-CA and/or auxin and tested for their activity. In the presence of cis-CA, lettuce root growth was inhibited; however, the addition of some cis-CA derivatives restored control-level root growth. Four compounds, (Z)-3-(4-isopropylphenyl)acrylic acid, (Z)-3-(3-butoxyphenyl)acrylic acid, (Z)-3-[3-(pentyloxy)phenyl]acrylic acid, and (Z)-3-(naphthalen-1-yl)acrylic acid were selected as candidates for a cis-CA selective suppressor they allowed the recovery of root growth from inhibition by cis-CA treatment without any effects on the IAA-induced effect or elongating activity by themselves. Three candidates significantly ameliorated the root shortening by the potent inhibitor derived from cis-CA. In brief, we have found some cis-CA selective suppressors which have never been reported from inactive cis-CA derivatives for root growth inhibition. cis-CA selective suppressors will play an important role in elucidating the mechanism of plant growth regulation. PMID:24881667

  8. Optimization of the Central Heterocycle of α-Ketoheterocycle Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Garfunkle, Joie; Ezzili, Cyrine; Rayl, Thomas J.; Hochstatter, Dustin G.; Hwang, Inkyu; Boger, Dale L.

    2008-01-01

    The synthesis and evaluation of a refined series of α-ketoheterocycles based on the oxazole 2 (OL-135) incorporating systematic changes in the central heterocycle bearing a key set of added substituents are described. The nature of the central heterocycle, even within the systematic and minor perturbations explored herein, significantly influenced the inhibitor activity: 1,3,4-oxadiazoles and 1,2,4-oxadiazoles 9 > tetrazoles, the isomeric 1,2,4-oxadiazoles 10, 1,3,4-thiadiazoles > oxazoles including 2 > 1,2-diazines > thiazoles > 1,3,4-triazoles. Most evident in these trends is the observation that introduction of an additional heteroatom at position 4 (oxazole numbering, N > O > CH) substantially increases activity that may be attributed to a reduced destabilizing steric interaction at the FAAH active site. Added heterocycle substituents displaying well defined trends may be utilized to enhance the inhibitor potency and, more significantly, to enhance the inhibitor selectivity. These trends, exemplified herein, emerge from both enhancements in the FAAH activity and simultaneous disruption of binding affinity for competitive off-target enzymes. PMID:18630870

  9. Arachidonoyl ethanolamide (AEA)-induced Apoptosis is Mediated by J-series Prostaglandins and is Enhanced by Fatty Acid Amide Hydrolase (FAAH) Blockade

    PubMed Central

    Kuc, Christian; Jenkins, Audrey; Van Dross, R. T.

    2011-01-01

    The endocannabinoid arachidonoyl ethanolamide (AEA) is a potent inducer of tumor cell apoptosis however its mechanism of cytotoxicity is unclear. A previous report from our laboratory showed that AEA induced cell death in a COX-2-dependent manner and in this report our data indicate that AEA-induced apoptosis is mediated by COX-2 metabolic products of the J-series. In experiments conducted with JWF2 keratinocytes which overexpress COX-2, AEA caused a concentration-regulated increase in J-series prostaglandin production and apoptosis. Similarly, cell treatment with exogenously added J-series prostaglandins (15-deoxy, Δ12,14 PGJ2 and PGJ2) induced apoptosis. AEA-induced apoptosis was inhibited by the antioxidant, N-acetyl cysteine, indicating that reactive oxygen species generation was required for apoptosis. Using antagonists of cannabinoid receptor 1, cannabinoid receptor 2, or TRPV1, it was observed that cannabinoid receptor inhibition did not block AEA-mediated cell death. In contrast, an inhibitor of fatty acid amide hydrolase (FAAH) potentiated AEA-induced J-series PG synthesis and apoptosis. These results suggest that the metabolism of AEA to J-series PGs regulates the induction of apoptosis in cells with elevated COX-2 levels. Our data further indicate that the proapoptotic activity of AEA can be enhanced by combining it with an inhibitor of FAAH. As such, AEA may be an effective agent to eliminate tumor cells that overexpress COX-2. PMID:21432910

  10. Scaffold hopping approach on the route to selective tankyrase inhibitors

    PubMed Central

    Liscio, Paride; Carotti, Andrea; Asciutti, Stefania; Ferri, Martina; Pires, Maira M.; Valloscuro, Sara; Ziff, Jacob; Clark, Neil R.; Macchiarulo, Antonio; Aaronson, Stuart A.; Pellicciari, Roberto; Camaioni, Emidio

    2015-01-01

    A virtual screening procedure was applied to identify new tankyrase inhibitors. Through pharmacophore screening of a compounds collection from the SPECS database, the methoxy[l]benzothieno[2,3-c]quinolin-6(5H)-one scaffold was identified as nicotinamide mimetic able to inhibit tankyrase activity at low micromolar concentration. In order to improve potency and selectivity, tandem structure-based and scaffold hopping approaches were carried out over the new scaffold leading to the discovery of the 2-(phenyl)-3H-benzo[4,5]thieno[3,2-d]pyrimidin-4-one as powerful chemotype suitable for tankyrase inhibition. The best compound 2-(4-tert-butyl-phenyl)-3H-benzo[4,5]thieno[3,2-d]pyrimidin-4-one (23) displayed nanomolar potencies (IC50s TNKS-1 = 21 nM and TNKS-2= 29 nM) and high selectivity when profiled against several other PARPs. Furthermore, a striking Wnt signaling, as well as cell growth inhibition, was observed assaying 23 in DLD-1 cancer cells. PMID:25299683

  11. Selectively Targeting Prostate Cancer with Antiandrogen Equipped Histone Deacetylase Inhibitors

    PubMed Central

    Gryder, Berkley E.; Akbashev, Michelle J.; Rood, Michael K.; Raftery, Eric D.; Meyers, Warren M.; Dillard, Paulette; Khan, Shafiq; Oyelere, Adegboyega K.

    2013-01-01

    Diverse cellular processes relevant to cancer progression are regulated by the acetylation status of proteins. Among such processes is chromatin remodeling via histone proteins, controlled by opposing histone deacetylase (HDAC) and histone acetyltransferase (HAT) enzymes. Histone deacetylase inhibitors (HDACi) show great promise in preclinical cancer models, but clinical trials treating solid tumors have failed to improve patient survival. This is due in part to an inability of HDACi to effectively accumulate in cancerous cells. To address this problem we designed HDACi with secondary pharmacophores to facilitate selective accumulation in malignant cells. We present the first example of HDACi compounds targeted to prostate tumors by equipping them with the additional ability to bind the androgen receptor (AR) with non-steroidal antiandrogen moieties. Leads among these new dual-acting molecules bind to the AR and halt AR transcriptional activity at lower concentrations than clinical antiandrogens. They inhibit key isoforms of HDAC with low nanomolar potency. Fluorescent microscopy reveals varying degrees of AR nuclear localization in response to these compounds that correlates with their HDAC activity. These biological properties translate into potent anticancer activity against hormone dependent (AR+) LNCaP and to a lesser extent against hormone independent (AR−) DU145 prostate cancer, while having greatly reduced toxicity in non-cancerous cells. This illustrates that engaging multiple biological targets with a single chemical probe can achieve both potent and cell-type selective responses. PMID:24004176

  12. Selective serotonin reuptake inhibitor discontinuation syndrome: proposed diagnostic criteria.

    PubMed Central

    Black, K; Shea, C; Dursun, S; Kutcher, S

    2000-01-01

    OBJECTIVE: To establish specific criteria by which selective serotonin reuptake inhibitor (SSRI) discontinuation syndrome may be identified. DATA SOURCES: MEDLINE and PSYCHLIT databases were searched for case reports published from 1986 to 1997 inclusive, and references of relevant articles were also searched. STUDY SELECTION: Forty-six case reports of symptoms following the discontinuation of fluoxetine, fluvoxamine, paroxetine or sertraline were selected. Three studies of SSRI discontinuation were also reviewed. DATA EXTRACTION: Demographic and treatment information, as well as the timing, duration, number, nature and frequency of dicontinuation symptoms. DATA SYNTHESIS: Paroxetine was most frequently implicated. The drug had been tapered in half of the cases. In some cases, symptom onset began during taper, whereas, in most cases, symptoms began within 1 to 3 days of drug discontinuation. Fifty-three different symptoms were reported, with dizziness being the most common. Other common symptoms were nausea or emesis, fatigue, headache, gait instability and insomnia. Shock-like sensations, paresthesia and visual disturbances were the most rare. Without intervention, symptoms persisted for more than a week in half of the cases. In cases in which the SSRI was restarted, symptoms resolved within 72 hours. In some cases, withdrawal symptoms recurred when the same SSRI was again discontinued. CONCLUSIONS: Findings were used to construct diagnostic criteria for the SSRI discontinuation syndrome. These criteria are 2 or more of the following symptoms developing within 1 to 7 days of discontinuation or reduction in dosage of an SSRI after at least 1 month's use, when these symptoms cause clinically significant distress or impairment and are not due to a general medical condition or recurrence of a mental disorder: dizziness, light-headedness, vertigo or feeling faint; shock-like sensations or paresthesia; anxiety; diarrhea; fatigue; gait instability; headache; insomnia

  13. Selective and non-selective cyclooxygenase inhibitors delay stress fracture healing in the rat ulna.

    PubMed

    Kidd, Lisa J; Cowling, Nick R; Wu, Andy C; Kelly, Wendy L; Forwood, Mark R

    2013-02-01

    Anti-inflammatory drugs are widely used to manage pain associated with stress fractures (SFxs), but little is known about their effects on healing of those injuries. We hypothesized that selective and non-selective anti-inflammatory treatments would retard the healing of SFx in the rat ulna. SFxs were created by cyclic loading of the ulna in Wistar rats. Ulnae were harvested 2, 4 or 6 weeks following loading. Rats were treated with non-selective NSAID, ibuprofen (30 mg/kg/day); selective COX-2 inhibition, [5,5-dimethyl-3-3 (3 fluorophenyl)-4-(4 methylsulfonal) phenyl-2 (5H)-furanone] (DFU) (2.0 mg/kg/day); or the novel c5a anatagonist PMX53 (10 mg/kg/day, 4 and 6 weeks only); with appropriate vehicle as control. Quantitative histomorphometric measurements of SFx healing were undertaken. Treatment with the selective COX-2 inhibitor, DFU, reduced the area of resorption along the fracture line at 2 weeks, without affecting bone formation at later stages. Treatment with the non-selective, NSAID, ibuprofen decreased both bone resorption and bone formation so that there was significantly reduced length and area of remodeling and lamellar bone formation within the remodeling unit at 6 weeks after fracture. The C5a receptor antagonist PMX53 had no effect on SFx healing at 4 or 6 weeks after loading, suggesting that PMX53 would not delay SFx healing. Both selective COX-2 inhibitors and non-selective NSAIDs have the potential to compromise SFx healing, and should be used with caution when SFx is diagnosed or suspected. PMID:22847634

  14. Design of highly potent urea-based, exosite-binding inhibitors selective for glutamate carboxypeptidase II.

    PubMed

    Tykvart, Jan; Schimer, Jiří; Jančařík, Andrej; Bařinková, Jitka; Navrátil, Václav; Starková, Jana; Šrámková, Karolína; Konvalinka, Jan; Majer, Pavel; Šácha, Pavel

    2015-05-28

    We present here a structure-aided design of inhibitors targeting the active site as well as exosites of glutamate carboxypeptidase II (GCPII), a prostate cancer marker, preparing potent and selective inhibitors that are more than 1000-fold more active toward GCPII than its closest human homologue, glutamate carboxypeptidase III (GCPIII). Additionally, we demonstrate that the prepared inhibitor conjugate can be used for sensitive and selective imaging of GCPII in mammalian cells. PMID:25923815

  15. Selective Serotonin Reuptake Inhibitors and Endothelial Function in Women

    PubMed Central

    Czarkowski, Kathryn A.; Child, Josiah; Howes, Christopher; Epperson, C. Neill

    2014-01-01

    Abstract Background: Among women worldwide, major depression (MDD) and heart disease rank first and second, respectively, in burden of disease. Although selective serotonin reuptake inhibitors (SSRIs) are frequently prescribed, possible inhibition of nitric oxide (NO) function has caused concerns about their effects on protective vascular mechanisms. Our study aimed to determine the effect of SSRIs on flow-mediated vascular dilatation (FMD), platelet aggregation, and platelet NO production among women. Methods: Women (n=28) without known cardiovascular disease were recruited prior to undergoing SSRI treatment for MDD, postpartum depression (PPD), or premenstrual dysphoric disorder (PMDD). Symptoms were quantified using the Hamilton Depression/Anxiety and Beck Depression scales. FMD, platelet aggregation, and platelet NO production were measured before and after 1 month of SSRI (sertraline, fluoxetine, or paroxetine) therapy. Results: Depression and anxiety symptoms decreased significantly with SSRI treatment (ps <0.01). FMD and platelet aggregation did not differ between pre- and posttreatment, although FMD rose to the normal range (≥8%) in two of three women with abnormal FMD prior to SSRI treatment. We observed a 21% decrease (p=0.024) in platelet NO production. Conclusions: SSRI treatment had little effect on FMD or platelet aggregation. The health impact of decreased NO production is unclear, particularly in this relatively young group of women without cardiovascular disease, but should be considered in future studies focusing on SSRI safety in patients with cardiovascular disease. PMID:24886268

  16. Selective serotonin reuptake inhibitor drug interactions in patients receiving statins.

    PubMed

    Andrade, Chittaranjan

    2014-02-01

    Elderly patients commonly receive statin drugs for the primary or secondary prevention of cardiovascular and cerebrovascular events. Elderly patients also commonly receive antidepressant drugs, usually selective serotonin reuptake inhibitors (SSRIs), for the treatment of depression, anxiety, or other conditions. SSRIs are associated with many pharmacokinetic drug interactions related to the inhibition of the cytochrome P450 (CYP) metabolic pathways. There is concern that drugs that inhibit statin metabolism can trigger statin adverse effects, especially myopathy (which can be potentially serious, if rhabdomyolysis occurs). However, a detailed literature review of statin metabolism and of SSRI effects on CYP enzymes suggests that escitalopram, citalopram, and paroxetine are almost certain to be safe with all statins, and rosuvastatin, pitavastatin, and pravastatin are almost certain to be safe with all SSRIs. Even though other SSRI-statin combinations may theoretically be associated with risks, the magnitude of the pharmacokinetic interaction is likely to be below the threshold for clinical significance. Risk, if at all, lies in combining fluvoxamine with atorvastatin, simvastatin, or lovastatin, and even this risk can be minimized by using lower statin doses and monitoring the patient. PMID:24602259

  17. Early Onset of Selective Serotonin Reuptake Inhibitor Antidepressant Action

    PubMed Central

    Taylor, Matthew J.; Freemantle, Nick; Geddes, John R.; Bhagwagar, Zubin

    2008-01-01

    Context: Selective serotonin reuptake inhibitors (SSRIs) are often described as having a delayed onset of effect in the treatment of depression. However, some trials have reported clinical improvement as early as the first week of treatment. Objective: To test the alternative hypotheses of delayed vs early onset of antidepressant action with SSRIs in patients with unipolar depression. Data Sources: Trials identified by searching CENTRAL, The Cochrane Collaboration database of controlled trials (2005), and the reference lists of identified trials and other systematic reviews. Study Selection: Randomized controlled trials of SSRIs vs placebo for the treatment of unipolar depression in adults that reported outcomes for at least 2 time points in the first 4 weeks of treatment (50 trials from >500 citations identified). Trials were excluded if limited to participants older than 65 years or specific comorbidities. Data Extraction: Data were extracted on trial design, participant characteristics, and outcomes by a single reviewer. Data Synthesis: Pooled estimates of treatment effect on depressive symptom rating scales were calculated for weeks 1 through 6 of treatment. In the primary analysis, the pattern of response seen was tested against alternative models of onset of response. The primary analysis incorporated data from 28 randomized controlled trials (n=5872). A model of early treatment response best fit the experimental data. Treatment with SSRIs rather than placebo was associated with clinical improvement by the end of the first week of use. A secondary analysis indicated an increased chance of achieving a 50% reduction in Hamilton Depression Rating Scale scores by 1 week (relative risk, 1.64; 95% confidence interval, 1.2-2.25) with SSRI treatment compared with placebo. Conclusions: Treatment with SSRIs is associated with symptomatic improvement in depression by the end of the first week of use, and the improvement continues at a decreasing rate for at least 6

  18. Degradation of potent Rubisco inhibitor by selective sugar phosphatase.

    PubMed

    Bracher, Andreas; Sharma, Anurag; Starling-Windhof, Amanda; Hartl, F Ulrich; Hayer-Hartl, Manajit

    2015-01-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyses the conversion of atmospheric carbon dioxide into organic compounds in photosynthetic organisms. Alongside carboxylating the five-carbon sugar ribulose-1,5-bisphosphate (RuBP)(1-3), Rubisco produces a small amount of xylulose-1,5-bisphosphate (XuBP), a potent inhibitor of Rubisco(4). The AAA+ protein Rubisco activase removes XuBP from the active site of Rubisco in an ATP-dependent process(5,6). However, free XuBP rapidly rebinds to Rubisco, perpetuating its inhibitory effect. Here, we combine biochemical and structural analyses to show that the CbbY protein of the photosynthetic bacterium Rhodobacter sphaeroides and Arabidopsis thaliana is a highly selective XuBP phosphatase. We also show that CbbY converts XuBP to the non-inhibitory compound xylulose-5-phosphate, which is recycled back to RuBP. We solve the crystal structures of CbbY from R. sphaeroides and A. thaliana, and through mutational analysis show that the cap domain of the protein confers the selectivity for XuBP over RuBP. Finally, in vitro experiments with CbbY from R. sphaeroides reveal that CbbY cooperates with Rubisco activase to prevent a detrimental build-up of XuBP at the Rubisco active site. We suggest that CbbY, which is conserved in algae and plants, is an important component of the cellular machinery that has evolved to deal with the shortcomings of the ancient enzyme Rubisco. PMID:27246049

  19. Transcriptional Profiling of a Selective CREB Binding Protein Bromodomain Inhibitor Highlights Therapeutic Opportunities.

    PubMed

    Chekler, Eugene L Piatnitski; Pellegrino, Jessica A; Lanz, Thomas A; Denny, R Aldrin; Flick, Andrew C; Coe, Jotham; Langille, Jonathan; Basak, Arindrajit; Liu, Shenping; Stock, Ingrid A; Sahasrabudhe, Parag; Bonin, Paul D; Lee, Kevin; Pletcher, Mathew T; Jones, Lyn H

    2015-12-17

    Bromodomains are involved in transcriptional regulation through the recognition of acetyl lysine modifications on diverse proteins. Selective pharmacological modulators of bromodomains are lacking, although the largely hydrophobic nature of the pocket makes these modules attractive targets for small-molecule inhibitors. This work describes the structure-based design of a highly selective inhibitor of the CREB binding protein (CBP) bromodomain and its use in cell-based transcriptional profiling experiments. The inhibitor downregulated a number of inflammatory genes in macrophages that were not affected by a selective BET bromodomain inhibitor. In addition, the CBP bromodomain inhibitor modulated the mRNA level of the regulator of G-protein signaling 4 (RGS4) gene in neurons, suggesting a potential therapeutic opportunity for CBP inhibitors in the treatment of neurological disorders. PMID:26670081

  20. CCT241533 is a potent and selective inhibitor of CHK2 which potentiates the cytotoxicity of PARP inhibitors

    PubMed Central

    Anderson, Victoria E; Walton, Michael I; Eve, Paul D; Boxall, Katherine J; Antoni, Laurent; Caldwell, John J; Pearl, Laurence H; Oliver, Antony W; Collins, Ian; Garrett, Michelle D

    2016-01-01

    CHK2 is a checkpoint kinase involved in the ATM-mediated response to double strand DNA breaks. Its potential as a drug target is still unclear but inhibitors of CHK2 may increase the efficacy of genotoxic cancer therapies in a p53 mutant background by eliminating one of the checkpoints or DNA repair pathways contributing to cellular resistance. We report here the identification and characterization of a novel CHK2 kinase inhibitor, CCT241533. X-ray crystallography confirmed that CCT241533 bound to CHK2 in the ATP pocket. This compound inhibits CHK2 with an IC50 of 3 nM and shows minimal cross reactivity against a panel of kinases at 1 μM. CCT241533 blocked CHK2 activity in human tumor cell lines in response to DNA damage, as demonstrated by inhibition of CHK2 autophosphorylation at S516, band-shift mobility changes and HDMX degradation. CCT241533 did not potentiate the cytotoxicity of a selection of genotoxic agents in several cell lines. However, this compound significantly potentiates the cytotoxicity of two structurally distinct Poly (ADP-ribose) polymerase (PARP) inhibitors. Clear induction of the pS516 CHK2 signal was seen with a PARP inhibitor alone and this activation was abolished by CCT241533, implying that the potentiation of PARP inhibitor cell killing by CCT241533 was due to inhibition of CHK2. Consequently CHK2 inhibitors may have therapeutic activity in combination with PARP inhibitors. PMID:21239475

  1. Synthesis and structure-activity relationship studies of O-biphenyl-3-yl carbamates as peripherally restricted fatty acid amide hydrolase inhibitors.

    PubMed

    Moreno-Sanz, Guillermo; Duranti, Andrea; Melzig, Laurin; Fiorelli, Claudio; Ruda, Gian Filippo; Colombano, Giampiero; Mestichelli, Paola; Sanchini, Silvano; Tontini, Andrea; Mor, Marco; Bandiera, Tiziano; Scarpelli, Rita; Tarzia, Giorgio; Piomelli, Daniele

    2013-07-25

    The peripherally restricted fatty acid amide hydrolase (FAAH) inhibitor URB937 (3, cyclohexylcarbamic acid 3'-carbamoyl-6-hydroxybiphenyl-3-yl ester) is extruded from the brain and spinal cord by the Abcg2 efflux transporter. Despite its inability to enter the central nervous system (CNS), 3 exerts profound antinociceptive effects in mice and rats, which result from the inhibition of FAAH in peripheral tissues and the consequent enhancement of anandamide signaling at CB1 cannabinoid receptors localized on sensory nerve endings. In the present study, we examined the structure-activity relationships (SAR) for the biphenyl region of compound 3, focusing on the carbamoyl and hydroxyl groups in the distal and proximal phenyl rings. Our SAR studies generated a new series of peripherally restricted FAAH inhibitors and identified compound 35 (cyclohexylcarbamic acid 3'-carbamoyl-5-hydroxybiphenyl-3-yl ester) as the most potent brain-impermeant FAAH inhibitor disclosed to date. PMID:23822179

  2. Enhanced responsiveness to selective serotonin reuptake inhibitors during lactation.

    PubMed

    Jury, Nicholas J; McCormick, Betsy A; Horseman, Nelson D; Benoit, Stephen C; Gregerson, Karen A

    2015-01-01

    The physiology of mood regulation in the postpartum is poorly understood despite the fact that postpartum depression (PPD) is a common pathology. Serotonergic mechanisms and their dysfunction are widely presumed to be involved, which has led us to investigate whether lactation induces changes in central or peripheral serotonin (5-HT) systems and related affective behaviors. Brain sections from lactating (day 10 postpartum) and age-matched nulliparous (non-pregnant) C57BL/6J mice were processed for 5-HT immunohistochemistry. The total number of 5-HT immunostained cells and optical density were measured. Lactating mice exhibited lower immunoreactive 5-HT and intensity in the dorsal raphe nucleus when compared with nulliparous controls. Serum 5-HT was quantified from lactating and nulliparous mice using radioimmunoassay. Serum 5-HT concentrations were higher in lactating mice than in nulliparous controls. Affective behavior was assessed in lactating and non-lactating females ten days postpartum, as well as in nulliparous controls using the forced swim test (FST) and marble burying task (MBT). Animals were treated for the preceding five days with a selective serotonin reuptake inhibitor (SSRI, citalopram, 5mg/kg/day) or vehicle. Lactating mice exhibited a lower baseline immobility time during the FST and buried fewer marbles during the MBT as compared to nulliparous controls. Citalopram treatment changed these behaviors in lactating mice with further reductions in immobility during the FST and decreased marble burying. In contrast, the same regimen of citalopram treatment had no effect on these behaviors in either non-lactating postpartum or nulliparous females. Our findings demonstrate changes in both central and peripheral 5-HT systems associated with lactation, independent of pregnancy. They also demonstrate a significant interaction of lactation and responsiveness to SSRI treatment, which has important implications in the treatment of PPD. Although recent evidence

  3. Selective serotonin reuptake inhibitor use and risk of gestational hypertension

    PubMed Central

    Toh, Sengwee; Mitchell, Allen A.; Louik, Carol; Werler, Martha M.; Chambers, Christina D.; Hernández-Díaz, Sonia

    2009-01-01

    Objective To assess the effects of selective serotonin reuptake inhibitor (SSRI) use on risks of gestational hypertension (GHT) and preeclampsia. Method We used data from 5,731 women with non-malformed infants and no underlying hypertension who participated in the Slone Epidemiology Center Birth Defects Study in 1998-2007. GHT was defined as incident hypertension diagnosed after the 20th week of pregnancy with and without proteinuria (i.e., with and without preeclampsia). We compared the risks of GHT and preeclampsia between users and non-users of SSRIs during pregnancy. Relative risks (RR) and 95% confidence intervals (CI) were estimated by Cox proportional hazard models, adjusting for pre-pregnancy sociodemographic, reproductive, and medical factors. Results GHT was present in 9.0% of the 5,532 non-users and 19.1% of the 199 SSRI users; among users, GHT was present in 13.1% of the 107 women who used SSRIs only in the first trimester and in 26.1% of the 92 who continued SSRIs beyond the first trimester. For preeclampsia, the incidence was 2.4% among non-users, 3.7% among women who were exposed only in the first trimester and 15.2% among those who continued SSRIs beyond the first trimester. Compared with non-users, the adjusted RR of preeclampsia was 1.4 (95% CI: 0.5, 3.8) for women who discontinued and 4.9 (95% CI: 2.7, 8.8) for those who continued SSRIs. Conclusion Whether a causal factor or not, SSRI exposure late in pregnancy might identify women at increased risk for GHT and preeclampsia. Further investigation is required to separate the effects of SSRIs from those of underlying mood disorders. PMID:19122006

  4. Selective Serotonin Reuptake Inhibitor Suppression of HIV Infectivity and Replication

    PubMed Central

    Benton, Tami; Lynch, Kevin; Dubé, Benoit; Gettes, David R.; Tustin, Nancy B.; Lai, Jian Ping; Metzger, David S.; Blume, Joshua; Douglas, Steven D.; Evans, Dwight L.

    2010-01-01

    Objective To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down regulate HIV infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/AIDS. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells (NK) cells and CD8+ lymphocytes, key regulators of HIV infection. Methods Ex-vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication, in 48 depressed and non-depressed women. For both the acute and chronic infection models, HIV reverse transcriptase (RT) activity was measured in the citalopram treatment condition and the control condition. Results The SSRI significantly downregulated the RT response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. Conclusions These studies suggest that an SSRI enhances NK/CD8 non-cytolytic HIV suppression in HIV/AIDS and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV. PMID:20947783

  5. Selectivity Mechanism of ATP-Competitive Inhibitors for PKB and PKA.

    PubMed

    Wu, Ke; Pang, Jingzhi; Song, Dong; Zhu, Ying; Wu, Congwen; Shao, Tianqu; Chen, Haifeng

    2015-07-01

    Protein kinase B (PKB) acts as a central node on the PI3K kinase pathway. Constitutive activation and overexpression of PKB have been identified to involve in various cancers. However, protein kinase A (PKA) sharing high homology with PKB is essential for metabolic regulation. Therefore, specific targeting on PKB is crucial strategy in drug design and development for antitumor. Here, we had revealed the selectivity mechanism for PKB inhibitors with molecular dynamics simulation and 3D-QSAR methods. Selective inhibitors of PKB could form more hydrogen bonds and hydrophobic contacts with PKB than those with PKA. This could explain that selective inhibitor M128 is more potent to PKB than to PKA. Then, 3D-QSAR models were constructed for these selective inhibitors and evaluated by test set compounds. 3D-QSAR model comparison of PKB inhibitors and PKA inhibitors reveals possible methods to improve the selectivity of inhibitors. These models can be used to design new chemical entities and make quantitative prediction of the specific selective inhibitors before resorting to in vitro and in vivo experiment. PMID:25376656

  6. SELECTIVE AND NON-SELECTIVE METALLOPROTEINASE INHIBITORS REDUCE IL-1-INDUCED CARTILAGE DEGRADATION AND LOSS OF MECHANICAL PROPERTIES

    PubMed Central

    Wilson, Christopher G.; Palmer, Ashley W.; Zuo, Fengrong; Eugui, Elsie; Wilson, Stacy; Mackenzie, Rebecca; Sandy, John D.; Levenston, Marc E.

    2015-01-01

    Articular cartilage undergoes matrix degradation and loss of mechanical properties when stimulated with proinflammatory cytokines such as interleukin-1 (IL-1). Aggrecanases and matrix metalloproteinases (MMPs) are thought to be principal downstream effectors of cytokine-induced matrix catabolism, and aggrecanase- or MMP-selective inhibitors reduce or block matrix destruction in several model systems. The objective of this study was to use metalloproteinase inhibitors to perturb IL-1-induced matrix catabolism in bovine cartilage explants and examine their effects on changes in tissue compression and shear properties. Explanted tissue was stimulated with IL-1 for up to 24 days in the absence or presence of inhibitors which were aggrecanase-selective, MMP-selective, or non-selective. Analysis of conditioned media and explant digests revealed that aggrecanase-mediated aggrecanolysis was delayed to varying extents with all inhibitor treatments, but that aggrecan release persisted. Collagen degradation was abrogated by MMP- and non-selective inhibitors and reduced by the aggrecanase inhibitor. The inhibitors delayed but did not reduce loss of the equilibrium compression modulus, whereas the loss of dynamic compression and shear moduli was delayed and reduced. The data suggest that non-metalloproteinase mechanisms participate in IL-1-induced matrix degradation and loss of tissue material properties. PMID:17174540

  7. Novel mutant-selective EGFR kinase inhibitors against EGFR T790M

    SciTech Connect

    Zhou, Wenjun; Ercan, Dalia; Chen, Liang; Yun, Cai-Hong; Li, Danan; Capelletti, Marzia; Cortot, Alexis B.; Chirieac, Lucian; Iacob, Roxana E.; Padera, Robert; Engen, John R.; Wong, Kwok-Kin; Eck, Michael J.; Gray, Nathanael S.; Jänne, Pasi A.

    2010-01-12

    The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors in EGFR-mutant non-small-cell lung cancer (NSCLC) is limited by the development of drug-resistance mutations, including the gatekeeper T790M mutation. Strategies targeting EGFR T790M with irreversible inhibitors have had limited success and are associated with toxicity due to concurrent inhibition of wild-type EGFR. All current EGFR inhibitors possess a structurally related quinazoline-based core scaffold and were identified as ATP-competitive inhibitors of wild-type EGFR. Here we identify a covalent pyrimidine EGFR inhibitor by screening an irreversible kinase inhibitor library specifically against EGFR T790M. These agents are 30- to 100-fold more potent against EGFR T790M, and up to 100-fold less potent against wild-type EGFR, than quinazoline-based EGFR inhibitors in vitro. They are also effective in murine models of lung cancer driven by EGFR T790M. Co-crystallization studies reveal a structural basis for the increased potency and mutant selectivity of these agents. These mutant-selective irreversible EGFR kinase inhibitors may be clinically more effective and better tolerated than quinazoline-based inhibitors. Our findings demonstrate that functional pharmacological screens against clinically important mutant kinases represent a powerful strategy to identify new classes of mutant-selective kinase inhibitors.

  8. Identification of potent and selective MTH1 inhibitors.

    PubMed

    Petrocchi, Alessia; Leo, Elisabetta; Reyna, Naphtali J; Hamilton, Matthew M; Shi, Xi; Parker, Connor A; Mseeh, Faika; Bardenhagen, Jennifer P; Leonard, Paul; Cross, Jason B; Huang, Sha; Jiang, Yongying; Cardozo, Mario; Draetta, Giulio; Marszalek, Joseph R; Toniatti, Carlo; Jones, Philip; Lewis, Richard T

    2016-03-15

    Structure based design of a novel class of aminopyrimidine MTH1 (MutT homolog 1) inhibitors is described. Optimization led to identification of IACS-4759 (compound 5), a sub-nanomolar inhibitor of MTH1 with excellent cell permeability and good metabolic stability in microsomes. This compound robustly inhibited MTH1 activity in cells and proved to be an excellent tool for interrogation of the utility of MTH1 inhibition in the context of oncology. PMID:26898335

  9. Novel nonnucleoside inhibitors that select nucleoside inhibitor resistance mutations in human immunodeficiency virus type 1 reverse transcriptase.

    PubMed

    Zhang, Zhijun; Walker, Michelle; Xu, Wen; Shim, Jae Hoon; Girardet, Jean-Luc; Hamatake, Robert K; Hong, Zhi

    2006-08-01

    Mutations in and around the catalytic site of the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) are associated with resistance to nucleoside RT inhibitors (NRTIs), whereas changes in the hydrophobic pocket of the RT are attributed to nonnucleoside RT inhibitor (NNRTI) resistance. In this study, we report a novel series of nonnucleoside inhibitors of HIV-1, exemplified by VRX-329747 and VRX-413638, which inhibit both NNRTI- and NRTI-resistant HIV-1 isolates. Enzymatic studies indicated that these compounds are HIV-1 RT inhibitors. Surprisingly, however, following prolonged (6 months) tissue culture selection, this series of nonnucleoside inhibitors did not select NNRTI-resistant mutations in HIV-1 RT. Rather, four mutations (M41L, A62T/V, V118I, and M184V) known to cause resistance to NRTIs and two additional novel mutations (S68N and G112S) adjacent to the catalytic site of the enzyme were selected. Although the M184V mutation appears to be the initial mutation to establish resistance, this mutation alone confers only a two- to fourfold decrease in susceptibility to VRX-329747 and VRX-413638. At least two additional mutations must accumulate for significant resistance. Moreover, while VRX-329747-selected viruses are resistant to lamivudine and emtricitabine due to the M184V mutation, they remain susceptible to zidovudine, stavudine, dideoxyinosine, abacavir, tenofovir, and efavirenz. These results directly demonstrate that VRX-329747 and VRX-413638 are novel nonnucleoside inhibitors of HIV-1 RT with the potential to augment current therapies. PMID:16870771

  10. Functionalized N,N-Diphenylamines as Potent and Selective EPAC2 Inhibitors.

    PubMed

    Wild, Christopher T; Zhu, Yingmin; Na, Ye; Mei, Fang; Ynalvez, Marcus A; Chen, Haiying; Cheng, Xiaodong; Zhou, Jia

    2016-05-12

    N,N-Diphenylamines were discovered as potent and selective EPAC2 inhibitors. A study was conducted to determine the structure-activity relationships in a series of inhibitors of which several compounds displayed submicromolar potencies. Selectivity over the related EPAC1 protein was also demonstrated. Computational modeling reveals an allosteric site that is distinct from the cAMP binding domain shared by both EPAC isoforms, providing a theory with regards to subtype selectivity. PMID:27190593

  11. Monofluorophosphate is a selective inhibitor of respiratory sulfate-reducing microorganisms.

    PubMed

    Carlson, Hans K; Stoeva, Magdalena K; Justice, Nicholas B; Sczesnak, Andrew; Mullan, Mark R; Mosqueda, Lorraine A; Kuehl, Jennifer V; Deutschbauer, Adam M; Arkin, Adam P; Coates, John D

    2015-03-17

    Despite the environmental and economic cost of microbial sulfidogenesis in industrial operations, few compounds are known as selective inhibitors of respiratory sulfate reducing microorganisms (SRM), and no study has systematically and quantitatively evaluated the selectivity and potency of SRM inhibitors. Using general, high-throughput assays to quantitatively evaluate inhibitor potency and selectivity in a model sulfate-reducing microbial ecosystem as well as inhibitor specificity for the sulfate reduction pathway in a model SRM, we screened a panel of inorganic oxyanions. We identified several SRM selective inhibitors including selenate, selenite, tellurate, tellurite, nitrate, nitrite, perchlorate, chlorate, monofluorophosphate, vanadate, molydate, and tungstate. Monofluorophosphate (MFP) was not known previously as a selective SRM inhibitor, but has promising characteristics including low toxicity to eukaryotic organisms, high stability at circumneutral pH, utility as an abiotic corrosion inhibitor, and low cost. MFP remains a potent inhibitor of SRM growing by fermentation, and MFP is tolerated by nitrate and perchlorate reducing microorganisms. For SRM inhibition, MFP is synergistic with nitrite and chlorite, and could enhance the efficacy of nitrate or perchlorate treatments. Finally, MFP inhibition is multifaceted. Both inhibition of the central sulfate reduction pathway and release of cytoplasmic fluoride ion are implicated in the mechanism of MFP toxicity. PMID:25698072

  12. Discovery of N-substituted pyridinones as potent and selective inhibitors of p38 kinase

    SciTech Connect

    Selness, Shaun R.; Devraj, Rajesh V.; Monahan, Joseph B.; Boehm, Terri L.; Walker, John K.; Devadas, Balekudru; Durley, Richard C.; Kurumbail, Ravi; Shieh, Huey; Xing, Li; Hepperle, Michael; Rucker, Paul V.; Jerome, Kevin D.; Benson, Alan G.; Marrufo, Laura D.; Madsen, Heather M.; Hitchcock, Jeff; Owen, Tom J.; Christie, Lance; Promo, Michele A.; Hickory, Brian S.; Alvira, Edgardo; Naing, Win; Blevis-Bal, Radhika; Pfizer

    2010-10-18

    The identification and evolution of a series of potent and selective p38 inhibitors is described. p38 inhibitors based on a N-benzyl pyridinone high-throughput screening hit were prepared and their SAR explored. Their design was guided by ligand bound co-crystals of p38{alpha}. These efforts resulted in the identification of 12r and 19 as orally active inhibitors of p38 with significant efficacy in both acute and chronic models of inflammation.

  13. Corrosion inhibitor testing and selection for exploration and production: A user's perspective

    SciTech Connect

    Kapusta, S.D.

    1999-06-01

    Inhibitor users need simple, reliable, and representative tests to select the best product from a number of candidates. This article describes a procedure that can help users test and select inhibitors for carbon dioxide/hydrogen sulfide (CO[sub 2]/H[sub 2]S) corrosion in oil and gas production, in a fast and cost-effective manner. The selection is based on two criteria: performance (effectiveness) against corrosion, and compatibility with other chemicals. The compatibility of the inhibitor with the injection and production systems must be confirmed.

  14. Identification of a Novel and Selective Series of Itk Inhibitors via a Template-Hopping Strategy.

    PubMed

    Alder, Catherine M; Ambler, Martin; Campbell, Amanda J; Champigny, Aurelie C; Deakin, Angela M; Harling, John D; Harris, Carol A; Longstaff, Tim; Lynn, Sean; Maxwell, Aoife C; Mooney, Chris J; Scullion, Callum; Singh, Onkar M P; Smith, Ian E D; Somers, Donald O; Tame, Christopher J; Wayne, Gareth; Wilson, Caroline; Woolven, James M

    2013-10-10

    Inhibition of Itk potentially constitutes a novel, nonsteroidal treatment for asthma and other T-cell mediated diseases. In-house kinase cross-screening resulted in the identification of an aminopyrazole-based series of Itk inhibitors. Initial work on this series highlighted selectivity issues with several other kinases, particularly AurA and AurB. A template-hopping strategy was used to identify a series of aminobenzothiazole Itk inhibitors, which utilized an inherently more selective hinge binding motif. Crystallography and modeling were used to rationalize the observed selectivity. Initial exploration of the SAR around this series identified potent Itk inhibitors in both enzyme and cellular assays. PMID:24900590

  15. Behavioral destabilization induced by the selective serotonin reuptake inhibitor fluoxetine

    PubMed Central

    2011-01-01

    Background Selective serotonin reuptake inhibitors (SSRIs) are widely used to treat mood and anxiety disorders. However, neuronal bases for both beneficial and adverse effects of SSRIs remain poorly understood. We have recently shown that the SSRI fluoxetine can reverse the state of maturation of hippocampal granule cells in adult mice. The granule cell "dematuration" is induced in a large population of granule cells, and greatly changes functional and physiological properties of these cells. Here we show that this unique form of neuronal plasticity is correlated with a distinct change in behavior of mice. Results We chronically treated adult male mice with fluoxetine, and examined its effect on several forms of behavior of mice. During fluoxetine treatments, mice showed a marked increase in day-to-day fluctuations of home cage activity levels that was characterized by occasional switching between hypoactivity and hyperactivity within a few days. This destabilized cage activity was accompanied by increased anxiety-related behaviors and could be observed up to 4 weeks after withdrawal from fluoxetine. As reported previously, the granule cell dematuration by fluoxetine includes a reduction of synaptic facilitation at the granule cell output, mossy fiber, synapse to the juvenile level. Mossy fiber synaptic facilitation examined electrophysiologically in acute hippocampal slices also remained suppressed after fluoxetine withdrawal and significantly correlated with the fluctuation of cage activity levels in individual mice. Furthermore, in mice lacking the 5-HT4 receptor, in which the granule cell dematuration has been shown to be attenuated, fluoxetine had no significant effect on the fluctuation of cage activity levels. Conclusions Our results demonstrate that the SSRI fluoxetine can induce marked day-to-day changes in activity levels of mice in the familiar environment, and that the dematuration of the hippocampal granule cells is closely associated with the

  16. Biochemical And Structural Evaluation of Highly Selective 2-Arylbenzoxazole-Based Transthyretin Amyloidogenesis Inhibitors

    SciTech Connect

    Johnson, S.M.; Connelly, S.; Wilson, I.A.; Kelly, J.W.

    2009-05-18

    To develop potent transthyretin (TTR) amyloidogenesis inhibitors that also display high binding selectivity in blood, it proves useful to systematically optimize each of the three substructural elements that comprise a typical inhibitor: the two aryl rings and the linker joining them. In the first study, described herein, structural modifications to one aryl ring were evaluated by screening a library of 2-arylbenzoxazoles bearing thyroid hormone-like aryl substituents on the 2-aryl ring. Several potent and highly selective amyloidogenesis inhibitors were identified that exhibit minimal thyroid hormone nuclear receptor and COX-1 binding. High resolution crystal structures (1.3-1.5 A) of three inhibitors (2f, 4f, and 4d) in complex with TTR were obtained to characterize their binding orientation. Collectively, the results demonstrate that thyroid hormone-like substitution patterns on one aryl ring lead to potent and highly selective TTR amyloidogenesis inhibitors that lack undesirable thyroid hormone receptor or COX-1 binding.

  17. The selectivity of protein kinase inhibitors: a further update

    PubMed Central

    Bain, Jenny; Plater, Lorna; Elliott, Matt; Shpiro, Natalia; Hastie, C. James; Mclauchlan, Hilary; Klevernic, Iva; Arthur, J. Simon C.; Alessi, Dario R.; Cohen, Philip

    2007-01-01

    The specificities of 65 compounds reported to be relatively specific inhibitors of protein kinases have been profiled against a panel of 70–80 protein kinases. On the basis of this information, the effects of compounds that we have studied in cells and other data in the literature, we recommend the use of the following small-molecule inhibitors: SB 203580/SB202190 and BIRB 0796 to be used in parallel to assess the physiological roles of p38 MAPK (mitogen-activated protein kinase) isoforms, PI-103 and wortmannin to be used in parallel to inhibit phosphatidylinositol (phosphoinositide) 3-kinases, PP1 or PP2 to be used in parallel with Src-I1 (Src inhibitor-1) to inhibit Src family members; PD 184352 or PD 0325901 to inhibit MKK1 (MAPK kinase-1) or MKK1 plus MKK5, Akt-I-1/2 to inhibit the activation of PKB (protein kinase B/Akt), rapamycin to inhibit TORC1 [mTOR (mammalian target of rapamycin)–raptor (regulatory associated protein of mTOR) complex], CT 99021 to inhibit GSK3 (glycogen synthase kinase 3), BI-D1870 and SL0101 or FMK (fluoromethylketone) to be used in parallel to inhibit RSK (ribosomal S6 kinase), D4476 to inhibit CK1 (casein kinase 1), VX680 to inhibit Aurora kinases, and roscovitine as a pan-CDK (cyclin-dependent kinase) inhibitor. We have also identified harmine as a potent and specific inhibitor of DYRK1A (dual-specificity tyrosine-phosphorylated and -regulated kinase 1A) in vitro. The results have further emphasized the need for considerable caution in using small-molecule inhibitors of protein kinases to assess the physiological roles of these enzymes. Despite being used widely, many of the compounds that we analysed were too non-specific for useful conclusions to be made, other than to exclude the involvement of particular protein kinases in cellular processes. PMID:17850214

  18. Characterisation of (R)-2-(2-Fluorobiphenyl-4-yl)-N-(3-Methylpyridin-2-yl)Propanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor

    PubMed Central

    Gouveia-Figueira, Sandra; Karlsson, Jessica; Deplano, Alessandro; Hashemian, Sanaz; Svensson, Mona; Fredriksson Sundbom, Marcus; Congiu, Cenzo; Onnis, Valentina; Fowler, Christopher J.

    2015-01-01

    Background Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH) and substrate selective cyclooxygenase (COX-2) inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl)-N-(3-methylpyridin-2-yl)propanamide (Flu-AM1). These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known. Methodology/Principal Findings COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG) as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA) as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R)-Flu-AM1, COX-1 (arachidonic acid) 6 μM; COX-2 (arachidonic acid) 20 μM; COX-2 (2-AG) 1 μM; (S)-Flu-AM1, COX-1 (arachidonic acid) 3 μM; COX-2 (arachidonic acid) 10 μM; COX-2 (2-AG) 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R)-Flu-AM1 (10 μM) greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R)-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM). Conclusions/Significance Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the

  19. 9H-Carbazole-1-carboxamides as potent and selective JAK2 inhibitors.

    PubMed

    Zimmermann, Kurt; Sang, Xiaopeng; Mastalerz, Harold A; Johnson, Walter L; Zhang, Guifen; Liu, Qingjie; Batt, Douglas; Lombardo, Louis J; Vyas, Dinesh; Trainor, George L; Tokarski, John S; Lorenzi, Matthew V; You, Dan; Gottardis, Marco M; Lippy, Jonathan; Khan, Javed; Sack, John S; Purandare, Ashok V

    2015-07-15

    The discovery, synthesis, and characterization of 9H-carbazole-1-carboxamides as potent and selective ATP-competitive inhibitors of Janus kinase 2 (JAK2) are discussed. Optimization for JAK family selectivity led to compounds 14 and 21, with greater than 45-fold selectivity for JAK2 over all other members of the JAK kinase family. PMID:25987372

  20. Structure-activity relationship studies on 1-heteroaryl-3-phenoxypropan-2-ones acting as inhibitors of cytosolic phospholipase A2α and fatty acid amide hydrolase: replacement of the activated ketone group by other serine traps.

    PubMed

    Sundermann, Tom; Hanekamp, Walburga; Lehr, Matthias

    2016-08-01

    Cytosolic phospholipase A2α (cPLA2α) and fatty acid amide hydrolase (FAAH) are serine hydrolases. cPLA2α is involved in the generation of pro-inflammatory lipid mediators, FAAH terminates the anti-inflammatory effects of endocannabinoids. Therefore, inhibitors of these enzymes may represent new drug candidates for the treatment of inflammation. We have reported that certain 1-heteroarylpropan-2-ones are potent inhibitors of cPLA2α and FAAH. The serine reactive ketone group of these compounds, which is crucial for enzyme inhibition, is readily metabolized resulting in inactive alcohol derivatives. In order to obtain metabolically more stable inhibitors, we replaced this moiety by α-ketoheterocyle, cyanamide and nitrile serine traps. Investigations on activity and metabolic stability of these substances revealed that in all cases an increased metabolic stability was accompanied by a loss of inhibitory potency against cPLA2α and FAAH, respectively. PMID:26153239

  1. Computational analysis of spiro-oxindole inhibitors of the MDM2-p53 interaction: insights and selection of novel inhibitors.

    PubMed

    Huang, Wei; Cai, Lulu; Chen, Can; Xie, Xin; Zhao, Qiong; Zhao, Xing; Zhou, Hong-yun; Han, Bo; Peng, Cheng

    2016-01-01

    Since MDM2 is an inhibitor of the p53 tumor suppressor, disrupting the MDM2-p53 interaction is a promising approach for cancer therapy. Here, we used molecular dynamics simulations followed by free energy decomposition analysis to study conformational changes in MDM2 induced by three known spiro-oxindole inhibitors. Analysis of individual energy terms suggests that van der Waals and electrostatic interactions explain much of the binding affinities of these inhibitors. Binding free energies calculated for the three inhibitors using the molecular mechanics-generalized Born surface area model were consistent with experimental data, suggesting the validity of this approach. Based on this structure-function analysis, several novel spiro-oxindole derivatives were selected and evaluated for their ability to block the MDM2-p53 interaction in vitro. These results suggest that combining in silico and experimental techniques can provide insights into the structure-function relationships of MDM2 inhibitors and guide the rational design of anticancer drugs targeting the MDM2-p53 interaction. PMID:25808617

  2. Selective Serotonin Reuptake Inhibitors and Violent Crime: A Cohort Study

    PubMed Central

    Molero, Yasmina; Lichtenstein, Paul; Zetterqvist, Johan; Gumpert, Clara Hellner; Fazel, Seena

    2015-01-01

    Background Although selective serotonin reuptake inhibitors (SSRIs) are widely prescribed, associations with violence are uncertain. Methods and Findings From Swedish national registers we extracted information on 856,493 individuals who were prescribed SSRIs, and subsequent violent crimes during 2006 through 2009. We used stratified Cox regression analyses to compare the rate of violent crime while individuals were prescribed these medications with the rate in the same individuals while not receiving medication. Adjustments were made for other psychotropic medications. Information on all medications was extracted from the Swedish Prescribed Drug Register, with complete national data on all dispensed medications. Information on violent crime convictions was extracted from the Swedish national crime register. Using within-individual models, there was an overall association between SSRIs and violent crime convictions (hazard ratio [HR] = 1.19, 95% CI 1.08–1.32, p < 0.001, absolute risk = 1.0%). With age stratification, there was a significant association between SSRIs and violent crime convictions for individuals aged 15 to 24 y (HR = 1.43, 95% CI 1.19–1.73, p < 0.001, absolute risk = 3.0%). However, there were no significant associations in those aged 25–34 y (HR = 1.20, 95% CI 0.95–1.52, p = 0.125, absolute risk = 1.6%), in those aged 35–44 y (HR = 1.06, 95% CI 0.83–1.35, p = 0.666, absolute risk = 1.2%), or in those aged 45 y or older (HR = 1.07, 95% CI 0.84–1.35, p = 0.594, absolute risk = 0.3%). Associations in those aged 15 to 24 y were also found for violent crime arrests with preliminary investigations (HR = 1.28, 95% CI 1.16–1.41, p < 0.001), non-violent crime convictions (HR = 1.22, 95% CI 1.10–1.34, p < 0.001), non-violent crime arrests (HR = 1.13, 95% CI 1.07–1.20, p < 0.001), non-fatal injuries from accidents (HR = 1.29, 95% CI 1.22–1.36, p < 0.001), and emergency inpatient or outpatient treatment for alcohol intoxication or misuse

  3. A road map to evaluate the proteome-wide selectivity of covalent kinase inhibitors.

    PubMed

    Lanning, Bryan R; Whitby, Landon R; Dix, Melissa M; Douhan, John; Gilbert, Adam M; Hett, Erik C; Johnson, Theodore O; Joslyn, Chris; Kath, John C; Niessen, Sherry; Roberts, Lee R; Schnute, Mark E; Wang, Chu; Hulce, Jonathan J; Wei, Baoxian; Whiteley, Laurence O; Hayward, Matthew M; Cravatt, Benjamin F

    2014-09-01

    Kinases are principal components of signal transduction pathways and the focus of intense basic and drug discovery research. Irreversible inhibitors that covalently modify non-catalytic cysteines in kinase active sites have emerged as valuable probes and approved drugs. Many protein classes, however, have functional cysteines, and therefore understanding the proteome-wide selectivity of covalent kinase inhibitors is imperative. Here, we accomplish this objective using activity-based protein profiling coupled with quantitative MS to globally map the targets, both specific and nonspecific, of covalent kinase inhibitors in human cells. Many of the specific off-targets represent nonkinase proteins that, notably, have conserved active site cysteines. We define windows of selectivity for covalent kinase inhibitors and show that, when these windows are exceeded, rampant proteome-wide reactivity and kinase target-independent cell death conjointly occur. Our findings, taken together, provide an experimental road map to illuminate opportunities and surmount challenges for the development of covalent kinase inhibitors. PMID:25038787

  4. Evaluation of NHS Carbamates as a Potent and Selective Class of Endocannabinoid Hydrolase Inhibitors

    PubMed Central

    2013-01-01

    Monoacylglycerol lipase (MAGL) is a principal metabolic enzyme responsible for hydrolyzing the endogenous cannabinoid (endocannabinoid) 2-arachidonoylglycerol (2-AG). Selective inhibitors of MAGL offer valuable probes to further understand the enzyme’s function in biological systems and may lead to drugs for treating a variety of diseases, including psychiatric disorders, neuroinflammation, and pain. N-Hydroxysuccinimidyl (NHS) carbamates have recently been identified as a promising class of serine hydrolase inhibitors that shows minimal cross-reactivity with other proteins in the proteome. Here, we explore NHS carbamates more broadly and demonstrate their potential as inhibitors of endocannabinoid hydrolases and additional enzymes from the serine hydrolase class. We extensively characterize an NHS carbamate 1a (MJN110) as a potent, selective, and in-vivo-active MAGL inhibitor. Finally, we demonstrate that MJN110 alleviates mechanical allodynia in a rat model of diabetic neuropathy, marking NHS carbamates as a promising class of MAGL inhibitors. PMID:23731016

  5. Structural characterizations of nonpeptidic thiadiazole inhibitors of matrix metalloproteinases reveal the basis for stromelysin selectivity.

    PubMed Central

    Finzel, B. C.; Baldwin, E. T.; Bryant, G. L.; Hess, G. F.; Wilks, J. W.; Trepod, C. M.; Mott, J. E.; Marshall, V. P.; Petzold, G. L.; Poorman, R. A.; O'Sullivan, T. J.; Schostarez, H. J.; Mitchell, M. A.

    1998-01-01

    The binding of two 5-substituted-1,3,4-thiadiazole-2-thione inhibitors to the matrix metalloproteinase stromelysin (MMP-3) have been characterized by protein crystallography. Both inhibitors coordinate to the catalytic zinc cation via an exocyclic sulfur and lay in an unusual position across the unprimed (P1-P3) side of the proteinase active site. Nitrogen atoms in the thiadiazole moiety make specific hydrogen bond interactions with enzyme structural elements that are conserved across all enzymes in the matrix metalloproteinase class. Strong hydrophobic interactions between the inhibitors and the side chain of tyrosine-155 appear to be responsible for the very high selectivity of these inhibitors for stromelysin. In these enzyme/inhibitor complexes, the S1' enzyme subsite is unoccupied. A conformational rearrangement of the catalytic domain occurs that reveals an inherent flexibility of the substrate binding region leading to speculation about a possible mechanism for modulation of stromelysin activity and selectivity. PMID:9792098

  6. Selection of potent chymotrypsin and elastase inhibitors from M13 phage library of basic pancreatic trypsin inhibitor (BPTI).

    PubMed

    Kiczak, L; Kasztura, M; Koscielska-Kasprzak, K; Dadlez, M; Otlewski, J

    2001-12-17

    The combinatorial approach offered by phage display has proved to be powerful in obtaining novel variants of canonical inhibitors of serine proteinases that show new binding patterns. We applied this strategy to search for variants of basic pancreatic trypsin inhibitor (BPTI) that would be strong inhibitors of two serine proteinases: bovine alpha-chymotrypsin and porcine pancreatic elastase. BPTI only moderately inhibits the first and does not inhibit the second enzyme. A representative library of 3.2 x 10(4) BPTI variants, randomized at P(1), P(1)', P(2)' and P(3)' positions of the proteinase binding loop, was displayed on the surface of phage M13. After four to five rounds of selection on the target proteinase consensus sequences of the inhibitor binding loop were obtained. In both cases, the variants selected differed from BPTI at two to four positions, with a strong preference for selection of hydrophobic residues. Nevertheless, five of these variants expressed in a free form appeared to be correctly folded, stable proteins, and did not aggregate during thermal denaturation. The midpoints of the thermal unfolding curves of these variants were lowered by 5-20 degrees C as compared to BPTI. The expressed variants proved to be new potent inhibitors of the target enzymes with association constants up to 6.9 x 10(9) M(-1) and 3.7 x 10(10) M(-1) for elastase and chymotrypsin, respectively. Thus, the inhibitory properties of BPTI were improved by as much as 7 x 10(6)-fold towards elastase and 420-fold towards chymotrypsin. PMID:11755204

  7. Identification of selective and potent inhibitors of fibroblast activation protein and prolyl oligopeptidase.

    PubMed

    Poplawski, Sarah E; Lai, Jack H; Li, Youhua; Jin, Zhiping; Liu, Yuxin; Wu, Wengen; Wu, Yong; Zhou, Yuhong; Sudmeier, James L; Sanford, David G; Bachovchin, William W

    2013-05-01

    Fibroblast activation protein (FAP) is a serine protease selectively expressed on reactive stromal fibroblasts of epithelial carcinomas. It is widely believed to play a role in tumor invasion and metastasis and therefore to represent a potential new drug target for cancer. Investigation into its biological function, however, has been hampered by the current unavailability of selective inhibitors. The challenge has been in identifying inhibitors that are selective for FAP over both the dipeptidyl peptidases (DPPs), with which it shares exopeptidase specificity, and prolyl oligopeptidase (PREP), with which it shares endopeptidase specificity. Here, we report the first potent FAP inhibitor with selectivity over both the DPPs and PREP, N-(pyridine-4-carbonyl)-d-Ala-boroPro (ARI-3099, 6). We also report a similarly potent and selective PREP inhibitor, N-(pyridine-3-carbonyl)-Val-boroPro (ARI-3531, 22). Both are boronic acid based inhibitors, demonstrating that high selectivity can be achieved using this electrophile. The inhibitors are stable, easy to synthesize, and should prove to be useful in helping to elucidate the biological functions of these two unique and interesting enzymes, as well as their potential as drug targets. PMID:23594271

  8. Identification of Selective and Potent Inhibitors of Fibroblast Activation Protein and Prolyl Oligopeptidase

    PubMed Central

    Poplawski, Sarah E.; Lai, Jack H.; Li, Youhua; Jin, Zhiping; Liu, Yuxin; Wu, Wengen; Wu, Yong; Zhou, Yuhong; Sudmeier, James L.; Sanford, David G.; Bachovchin, William W.

    2014-01-01

    Fibroblast activation protein (FAP) is a serine protease selectively expressed on reactive stromal fibroblasts of epithelial carcinomas. It is widely believed to play a role in tumor invasion and metastasis and therefore to represent a potential new drug target for cancer. Investigation into its biological function, however, has been hampered by the current unavailability of selective inhibitors. The challenge has been in identifying inhibitors that are selective for FAP over both the dipeptidyl peptidases (DPPs), with which it shares exopeptidase specificity, and prolyl oligopeptidase (PREP), with which it shares endopeptidase specificity. Here, we report the first potent FAP inhibitor with selectivity over both the DPPs and PREP, N-(pyridine-4-carbonyl)-d-Ala-boroPro (ARI-3099, 6). We also report a similarly potent and selective PREP inhibitor, N-(pyridine-3-carbonyl)-Val-boroPro (ARI-3531, 22). Both are boronic acid based inhibitors, demonstrating that high selectivity can be achieved using this electrophile. The inhibitors are stable, easy to synthesize, and should prove to be useful in helping to elucidate the biological functions of these two unique and interesting enzymes, as well as their potential as drug targets. PMID:23594271

  9. Treatment discontinuation with selective serotonin reuptake inhibitors compared with tricyclic antidepressants: a meta-analysis.

    PubMed Central

    Anderson, I. M.; Tomenson, B. M.

    1995-01-01

    OBJECTIVE--To assess treatment discontinuation rates with selective serotonin reuptake inhibitors compared with tricyclic antidepressants. DESIGN--Meta-analysis of 62 randomised controlled trials. SUBJECTS--6029 patients with major unipolar depression. MAIN OUTCOME MEASURES--Pooled risk ratios for drop out rates with respect to all cases of discontinuation and those due to side effects and treatment failure. RESULTS--The total discontinuation rate was 10% lower with selective serotonin reuptake inhibitors than with tricyclic antidepressants (risk ratio 0.90; 95% confidence interval 0.84 to 0.97) and the drop out rate due to side effects was 25% lower (risk ratio 0.75; 0.66 to 0.84). There was no significant difference between drug classes in the drop out rates for treatment failure. The risk ratios for drop out did not differ significantly between individual selective serotonin reuptake inhibitors. CONCLUSIONS--Selective serotonin reuptake inhibitors are better tolerated than tricyclic antidepressants as measured by total numbers of drop outs. The definite advantage to selective serotonin reuptake inhibitors is explained by fewer drop outs due to side effects. The overall difference, however, is comparatively small and may not be clinically relevant. Analyses of cost effectiveness should not overestimate the advantage to selective serotonin reuptake inhibitors. PMID:7613276

  10. Cyanohydrin as an Anchoring Group for Potent and Selective Inhibitors of Enterovirus 71 3C Protease.

    PubMed

    Zhai, Yangyang; Zhao, Xiangshuai; Cui, Zhengjie; Wang, Man; Wang, Yaxin; Li, Linfeng; Sun, Qi; Yang, Xi; Zeng, Debin; Liu, Ying; Sun, Yuna; Lou, Zhiyong; Shang, Luqing; Yin, Zheng

    2015-12-10

    Cyanohydrin derivatives as enterovirus 71 (EV71) 3C protease (3C(pro)) inhibitors have been synthesized and assayed for their biochemical and antiviral activities. Compared with the reported inhibitors, cyanohydrins (1S,2S,2'S,5S)-16 and (1R,2S,2'S,5S)-16 exhibited significantly improved activity and attractive selectivity profiles against other proteases, which were a result of the specific interactions between the cyanohydrin moiety and the catalytic site of 3C(pro). Cyanohydrin as an anchoring group with high selectivity and excellent inhibitory activity represents a useful choice for cysteine protease inhibitors. PMID:26571192

  11. Discovery of GSK2656157: An Optimized PERK Inhibitor Selected for Preclinical Development.

    PubMed

    Axten, Jeffrey M; Romeril, Stuart P; Shu, Arthur; Ralph, Jeffrey; Medina, Jesús R; Feng, Yanhong; Li, William Hoi Hong; Grant, Seth W; Heerding, Dirk A; Minthorn, Elisabeth; Mencken, Thomas; Gaul, Nathan; Goetz, Aaron; Stanley, Thomas; Hassell, Annie M; Gampe, Robert T; Atkins, Charity; Kumar, Rakesh

    2013-10-10

    We recently reported the discovery of GSK2606414 (1), a selective first in class inhibitor of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), which inhibited PERK activation in cells and demonstrated tumor growth inhibition in a human tumor xenograft in mice. In continuation of our drug discovery program, we applied a strategy to decrease inhibitor lipophilicity as a means to improve physical properties and pharmacokinetics. This report describes our medicinal chemistry optimization culminating in the discovery of the PERK inhibitor GSK2656157 (6), which was selected for advancement to preclinical development. PMID:24900593

  12. Selective and potent furin inhibitors protect cells from anthrax without significant toxicity.

    PubMed

    Remacle, Albert G; Gawlik, Katarzyna; Golubkov, Vladislav S; Cadwell, Gregory W; Liddington, Robert C; Cieplak, Piotr; Millis, Sherri Z; Desjardins, Roxane; Routhier, Sophie; Yuan, Xue Wen; Neugebauer, Witold A; Day, Robert; Strongin, Alex Y

    2010-06-01

    Furin and related proprotein convertases cleave the multibasic motifs R-X-R/K/X-R in the precursor proteins and, as a result, transform the latent proproteins into biologically active proteins and peptides. Furin is present both in the intracellular secretory pathway and at the cell surface. Intracellular furin processes its multiple normal cellular targets in the Golgi and secretory vesicle compartments while cell-surface furin appears to be essential only for the processing of certain pathogenic proteins and, importantly, anthrax. To design potent, safe and selective inhibitors of furin, we evaluated the potency and selectivity of the derivatized peptidic inhibitors modeled from the extended furin cleavage sequence of avian influenza A H5N1. We determined that the N- and C-terminal modifications of the original RARRRKKRT inhibitory scaffold produced selective and potent, nanomolar range, inhibitors of furin. These inhibitors did not interfere with the normal cellular function of furin because of the likely functional redundancy existing between furin and other proprotein convertases. These furin inhibitors, however, were highly potent in blocking the furin-dependent cell-surface processing of anthrax protective antigen-83 both in vitro and cell-based assays and in vivo. We conclude that the inhibitors we have designed have a promising potential as selective anthrax inhibitors, without affecting major cell functions. PMID:20197107

  13. Selective and potent furin inhibitors protect cells from anthrax without significant toxicity

    PubMed Central

    Remacle, Albert G.; Gawlik, Katarzyna; Golubkov, Vladislav S.; Cadwell, Gregory W.; Liddington, Robert C.; Cieplak, Piotr; Millis, Sherri Z.; Desjardins, Roxane; Routhier, Sophie; Yuan, Xue Wen; Neugebauer, Witold A.; Day, Robert; Strongin, Alex Y.

    2010-01-01

    Furin and related proprotein convertases cleave the multibasic motifs R-X-R/K/X-R in the precursor proteins and, as a result, transform the latent proproteins into biologically active proteins and peptides. Furin is present both in the intracellular secretory pathway and at the cell surface. Intracellular furin processes its multiple normal cellular targets in the Golgi and secretory vesicle compartments while cell-surface furin appears to be essential only for the processing of certain pathogenic proteins and, importantly, anthrax. To design potent, safe and selective inhibitors of furin, we evaluated the potency and selectivity of the derivatized peptidic inhibitors modeled from the extended furin cleavage sequence of avian influenza A H5N1. We determined that the N- and C-terminal modifications of the original RARRRKKRT inhibitory scaffold produced selective and potent, nanomolar range, inhibitors of furin. These inhibitors did not interfere with the normal cellular function of furin because of the likely functional redundancy existing between furin and other proprotein convertases. These furin inhibitors, however, were highly potent in blocking the furin-dependent cell-surface processing of anthrax protective antigen-83 both in vitro and cell-based assays and in vivo. We conclude that the inhibitors we have designed have a promising potential as selective anthrax inhibitors, without affecting major cell functions. PMID:20197107

  14. Synthesis and QSAR of Fatty Acid Amide Hydrolase Inhibitors: Modulation at the N-Portion of Biphenyl-3-yl Alkylcarbamates

    PubMed Central

    Mor, Marco; Lodola, Alessio; Rivara, Silvia; Vacondio, Federica; Duranti, Andrea; Tontini, Andrea; Sanchini, Silvano; Piersanti, Giovanni; Clapper, Jason R.; King, Alvin R.; Tarzia, Giorgio; Piomelli, Daniele

    2013-01-01

    Alkylcarbamic acid biphenyl-3-yl esters are a class of fatty acid amide hydrolase (FAAH) inhibitors that comprises cyclohexylcarbamic acid 3′-carbamoylbiphenyl-3-yl ester (URB597), a compound with analgesic, anxiolytic-like and antidepressant-like properties in rat and mouse models. Here, we extended the structure-activity relationships (SARs) for this class of compounds by replacing the cyclohexyl ring of the parent compound cyclohexylcarbamic acid biphenyl-3-yl ester (URB524) (IC50, for FAAH = 63 nM) with a selected set of substituents of different size, shape, flexibility and lipophilicity. Docking experiments and Linear Interaction Energy (LIE) calculations indicated that the N-terminal group of O-arylcarbamates fits within the lipophilic region of the substrate-binding site, mimicking the arachidonoyl chain of anandamide. Significant potency improvements were observed for the β-naphthylmethyl derivative 4q (IC50 = 5.3 nM) and its 3′-carbamoylbiphenyl-3-yl ester 4z (URB880, IC50 = 0.63 nM), indicating that shape complementarity and hydrogen bonds are crucial to obtain highly potent inhibitors. PMID:18507372

  15. In search of potent and selective inhibitors of neuronal nitric oxide synthase with more simple structures

    PubMed Central

    Jing, Qing; Li, Huiying; Fang, Jianguo; Roman, Linda J.; Martásek, Pavel; Poulos, Thomas L.; Silverman, Richard B.

    2013-01-01

    In certain neurodegenerative diseases damaging levels of nitric oxide (NO) are produced by neuronal nitric oxide synthase (nNOS). It, therefore, is important to develop inhibitors selective for nNOS that do not interfere with other NOS isoforms, especially endothelial NOS (eNOS), which is critical for proper functioning of the cardiovascular system. While we have been successful in developing potent and isoform-selective inhibitors, such as lead compounds 1 and 2, the ease of synthesis and bioavailability have been problematic. Here we describe a new series of compounds including crystal structures of NOS-inhibitor complexes that integrate the advantages of easy synthesis and good biological properties compared to the lead compounds. These results provide the basis for additional structure–activity relationship (SAR) studies to guide further improvement of isozyme selective inhibitors. PMID:23867386

  16. Structural Basis for Binding and Selectivity of Antimalarial and Anticancer Ethylenediamine Inhibitors to Protein Farnesyltransferase

    SciTech Connect

    Hast, Michael A.; Fletcher, Steven; Cummings, Christopher G.; Pusateri, Erin E.; Blaskovich, Michelle A.; Rivas, Kasey; Gelb, Michael H.; Voorhis, Wesley C.Van; Sebti, Said M.; Hamilton, Andrew D.; Beese, Lorena S. ); ); ); )

    2009-03-20

    Protein farnesyltransferase (FTase) catalyzes an essential posttranslational lipid modification of more than 60 proteins involved in intracellular signal transduction networks. FTase inhibitors have emerged as a significant target for development of anticancer therapeutics and, more recently, for the treatment of parasitic diseases caused by protozoan pathogens, including malaria (Plasmodium falciparum). We present the X-ray crystallographic structures of complexes of mammalian FTase with five inhibitors based on an ethylenediamine scaffold, two of which exhibit over 1000-fold selective inhibition of P. falciparum FTase. These structures reveal the dominant determinants in both the inhibitor and enzyme that control binding and selectivity. Comparison to a homology model constructed for the P. falciparum FTase suggests opportunities for further improving selectivity of a new generation of antimalarial inhibitors.

  17. (R)-Profens Are Substrate-Selective Inhibitors of Endocannabinoid Oxygenation by COX-2

    PubMed Central

    Duggan, Kelsey C.; Hermanson, Daniel J.; Musee, Joel; Prusakiewicz, Jeffery J.; Scheib, Jami L.; Carter, Bruce D.; Banerjee, Surajit; Oates, J.A.; Marnett, Lawrence J.

    2012-01-01

    Cyclooxygenase-2 (COX-2) catalyzes the oxygenation of arachidonic acid and the endocannabinoids, 2-arachidonoylglycerol and arachidonoylethanolamide. Evaluation of a series of COX-2 inhibitors revealed that many weak, competitive inhibitors of arachidonic acid oxygenation are potent inhibitors of endocannabinoid oxygenation. (R)-Enantiomers of ibuprofen, naproxen, and flurbiprofen, which are considered to be inactive as COX-2 inhibitors, are potent “substrate-selective inhibitors” of endocannabinoid oxygenation. Crystal structures of the COX-2-(R)-naproxen and COX-2-(R)-flurbiprofen complexes verified this unexpected binding and defined the orientation of the (R)-enantiomers relative to (S)-enantiomers. (R)-Profens selectively inhibited endocannabinoid oxygenation by lipopolysaccharide-stimulated dorsal root ganglion cells. Substrate-selective inhibition provides novel tools for investigating the role of COX-2 in endocannabinoid oxygenation and a possible explanation for the ability of (R)-profens to maintain endocannabinoid tone in models of neuropathic pain. PMID:22053353

  18. The design strategy of selective PTP1B inhibitors over TCPTP.

    PubMed

    Li, XiangQian; Wang, LiJun; Shi, DaYong

    2016-08-15

    Protein tyrosine phosphatase 1B (PTP1B) has already been well studied as a highly validated therapeutic target for diabetes and obesity. However, the lack of selectivity limited further studies and clinical applications of PTP1B inhibitors, especially over T-cell protein tyrosine phosphatase (TCPTP). In this review, we enumerate the published specific inhibitors of PTP1B, discuss the structure-activity relationships by analysis of their X-ray structures or docking results, and summarize the characteristic of selectivity related residues and groups. Furthermore, the design strategy of selective PTP1B inhibitors over TCPTP is also proposed. We hope our work could provide an effective way to gain specific PTP1B inhibitors. PMID:27353889

  19. 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

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

    PubMed

    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

  1. 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.

  2. Computational design of a time-dependent histone deacetylase 2 selective inhibitor.

    PubMed

    Zhou, Jingwei; Li, Min; Chen, Nanhao; Wang, Shenglong; Luo, Hai-Bin; Zhang, Yingkai; Wu, Ruibo

    2015-03-20

    Development of isoform-selective histone deacetylase (HDAC) inhibitors is of great biological and medical interest. Among 11 zinc-dependent HDAC isoforms, it is particularly challenging to achieve isoform inhibition selectivity between HDAC1 and HDAC2 due to their very high structural similarities. In this work, by developing and applying a novel de novo reaction-mechanism-based inhibitor design strategy to exploit the reactivity difference, we have discovered the first HDAC2-selective inhibitor, β-hydroxymethyl chalcone. Our bioassay experiments show that this new compound has a unique time-dependent selective inhibition on HDAC2, leading to about 20-fold isoform-selectivity against HDAC1. Furthermore, our ab initio QM/MM molecular dynamics simulations, a state-of-the-art approach to study reactions in biological systems, have elucidated how the β-hydroxymethyl chalcone can achieve the distinct time-dependent inhibition toward HDAC2. PMID:25546141

  3. High-throughput screening to identify selective inhibitors of microbial sulfate reduction (and beyond)

    NASA Astrophysics Data System (ADS)

    Carlson, H. K.; Coates, J. D.; Deutschbauer, A. M.

    2015-12-01

    The selective perturbation of complex microbial ecosystems to predictably influence outcomes in engineered and industrial environments remains a grand challenge for geomicrobiology. In some industrial ecosystems, such as oil reservoirs, sulfate reducing microorganisms (SRM) produce hydrogen sulfide which is toxic, explosive and corrosive. Current strategies to selectively inhibit sulfidogenesis are based on non-specific biocide treatments, bio-competitive exclusion by alternative electron acceptors or sulfate-analogs which are competitive inhibitors or futile/alternative substrates of the sulfate reduction pathway. Despite the economic cost of sulfidogenesis, there has been minimal exploration of the chemical space of possible inhibitory compounds, and very little work has quantitatively assessed the selectivity of putative souring treatments. We have developed a high-throughput screening strategy to target SRM, quantitatively ranked the selectivity and potency of hundreds of compounds and identified previously unrecognized SRM selective inhibitors and synergistic interactions between inhibitors. Once inhibitor selectivity is defined, high-throughput characterization of microbial community structure across compound gradients and identification of fitness determinants using isolate bar-coded transposon mutant libraries can give insights into the genetic mechanisms whereby compounds structure microbial communities. The high-throughput (HT) approach we present can be readily applied to target SRM in diverse environments and more broadly, could be used to identify and quantify the potency and selectivity of inhibitors of a variety of microbial metabolisms. Our findings and approach are relevant for engineering environmental ecosystems and also to understand the role of natural gradients in shaping microbial niche space.

  4. Amyloid precursor protein selective gamma-secretase inhibitors for treatment of Alzheimer's disease

    PubMed Central

    2010-01-01

    Introduction Inhibition of gamma-secretase presents a direct target for lowering Aβ production in the brain as a therapy for Alzheimer's disease (AD). However, gamma-secretase is known to process multiple substrates in addition to amyloid precursor protein (APP), most notably Notch, which has limited clinical development of inhibitors targeting this enzyme. It has been postulated that APP substrate selective inhibitors of gamma-secretase would be preferable to non-selective inhibitors from a safety perspective for AD therapy. Methods In vitro assays monitoring inhibitor potencies at APP γ-site cleavage (equivalent to Aβ40), and Notch ε-site cleavage, in conjunction with a single cell assay to simultaneously monitor selectivity for inhibition of Aβ production vs. Notch signaling were developed to discover APP selective gamma-secretase inhibitors. In vivo efficacy for acute reduction of brain Aβ was determined in the PDAPP transgene model of AD, as well as in wild-type FVB strain mice. In vivo selectivity was determined following seven days x twice per day (b.i.d.) treatment with 15 mg/kg/dose to 1,000 mg/kg/dose ELN475516, and monitoring brain Aβ reduction vs. Notch signaling endpoints in periphery. Results The APP selective gamma-secretase inhibitors ELN318463 and ELN475516 reported here behave as classic gamma-secretase inhibitors, demonstrate 75- to 120-fold selectivity for inhibiting Aβ production compared with Notch signaling in cells, and displace an active site directed inhibitor at very high concentrations only in the presence of substrate. ELN318463 demonstrated discordant efficacy for reduction of brain Aβ in the PDAPP compared with wild-type FVB, not observed with ELN475516. Improved in vivo safety of ELN475516 was demonstrated in the 7d repeat dose study in wild-type mice, where a 33% reduction of brain Aβ was observed in mice terminated three hours post last dose at the lowest dose of inhibitor tested. No overt in-life or post

  5. Combined Pan-RAF and MEK Inhibition Overcomes Multiple Resistance Mechanisms to Selective RAF Inhibitors.

    PubMed

    Whittaker, Steven R; Cowley, Glenn S; Wagner, Steve; Luo, Flora; Root, David E; Garraway, Levi A

    2015-12-01

    RAF and MEK inhibitors are effective in BRAF-mutant melanoma but not in BRAF-mutant colorectal cancer. To gain additional insights into this difference, we performed a genome-scale pooled shRNA enhancer screen in a BRAF-mutant, RAF inhibitor-resistant colorectal cancer cell line exposed to the selective RAF inhibitor PLX4720. We identified multiple genes along the receptor tyrosine kinase (RTK)/mitogen-activated protein kinase (MAPK) signaling axis that, when suppressed, either genetically or pharmacologically, sensitized cells to the selective RAF inhibitor through sustained inhibition of MAPK signaling. Strikingly, CRAF was a key mediator of resistance that could be overcome by the use of pan-RAF inhibitors in combination with a MEK inhibitor. Furthermore, the combination of pan-RAF and MEK inhibitors displayed strong synergy in melanoma and colorectal cancer cell lines with RAS-activating events such as RTK activation, KRAS mutation, or NF1 loss-of-function mutations. Combinations of selective RAF inhibitors, such as PLX4720 or dabrafenib, with MEK inhibitors did not incur such profound synergy, suggesting that inhibition of CRAF by pan-RAF inhibitors plays a key role in determining cellular response. Importantly, in contrast to the modest activity seen with single-agent treatment, dual pan-RAF and MEK inhibition results in the induction of apoptosis, greatly enhancing efficacy. Notably, combined pan-RAF and MEK inhibition can overcome intrinsic and acquired resistance to single-agent RAF/MEK inhibition, supporting dual pan-RAF and MEK inhibition as a novel therapeutic strategy for BRAF- and KRAS-mutant cancers. PMID:26351322

  6. Evolution of NADPH Oxidase Inhibitors: Selectivity and Mechanisms for Target Engagement

    PubMed Central

    Altenhöfer, Sebastian; Radermacher, Kim A.; Kleikers, Pamela W.M.; Wingler, Kirstin

    2015-01-01

    Abstract Significance: Oxidative stress, an excess of reactive oxygen species (ROS) production versus consumption, may be involved in the pathogenesis of different diseases. The only known enzymes solely dedicated to ROS generation are nicotinamide adenine dinucleotide phosphate (NADPH) oxidases with their catalytic subunits (NOX). After the clinical failure of most antioxidant trials, NOX inhibitors are the most promising therapeutic option for diseases associated with oxidative stress. Recent Advances: Historical NADPH oxidase inhibitors, apocynin and diphenylene iodonium, are un-specific and not isoform selective. Novel NOX inhibitors stemming from rational drug discovery approaches, for example, GKT137831, ML171, and VAS2870, show improved specificity for NADPH oxidases and moderate NOX isoform selectivity. Along with NOX2 docking sequence (NOX2ds)-tat, a peptide-based inhibitor, the use of these novel small molecules in animal models has provided preliminary in vivo evidence for a pathophysiological role of specific NOX isoforms. Critical Issues: Here, we discuss whether novel NOX inhibitors enable reliable validation of NOX isoforms' pathological roles and whether this knowledge supports translation into pharmacological applications. Modern NOX inhibitors have increased the evidence for pathophysiological roles of NADPH oxidases. However, in comparison to knockout mouse models, NOX inhibitors have limited isoform selectivity. Thus, their use does not enable clear statements on the involvement of individual NOX isoforms in a given disease. Future Directions: The development of isoform-selective NOX inhibitors and biologicals will enable reliable validation of specific NOX isoforms in disease models other than the mouse. Finally, GKT137831, the first NOX inhibitor in clinical development, is poised to provide proof of principle for the clinical potential of NOX inhibition. Antioxid. Redox Signal. 23, 406–427. PMID:24383718

  7. Lignocellulosic hydrolysate inhibitors selectively inhibit/deactivate cellulase performance.

    PubMed

    Mhlongo, Sizwe I; den Haan, Riaan; Viljoen-Bloom, Marinda; van Zyl, Willem H

    2015-12-01

    In this study, we monitored the inhibition and deactivation effects of various compounds associated with lignocellulosic hydrolysates on individual and combinations of cellulases. Tannic acid representing polymeric lignin residues strongly inhibited cellobiohydrolase 1 (CBH1) and β-glucosidase 1 (BGL1), but had a moderate inhibitory effect on endoglucanase 2 (EG2). Individual monomeric lignin residues had little or no inhibitory effect on hydrolytic enzymes. However, coniferyl aldehyde and syringaldehyde substantially decreased the activity of CBH1 and deactivated BGL1. Acetic and formic acids also showed strong inhibition of BGL1 but not CBH1 and EG2, whereas tannic, acetic and formic acid strongly inhibited a combination of CBH1 and EG2 during Avicel hydrolysis. Diminishing enzymatic hydrolysis is largely a function of inhibitor concentration and the enzyme-inhibitor relationship, rather than contact time during the hydrolysis process (i.e. deactivation). This suggests that decreased rates of hydrolysis during the enzymatic depolymerisation of lignocellulosic hydrolysates may be imparted by other factors related to substrate crystallinity and accessibility. PMID:26453468

  8. Tricyclic covalent inhibitors selectively target Jak3 through an active site thiol.

    PubMed

    Goedken, Eric R; Argiriadi, Maria A; Banach, David L; Fiamengo, Bryan A; Foley, Sage E; Frank, Kristine E; George, Jonathan S; Harris, Christopher M; Hobson, Adrian D; Ihle, David C; Marcotte, Douglas; Merta, Philip J; Michalak, Mark E; Murdock, Sara E; Tomlinson, Medha J; Voss, Jeffrey W

    2015-02-20

    The action of Janus kinases (JAKs) is required for multiple cytokine signaling pathways, and as such, JAK inhibitors hold promise for treatment of autoimmune disorders, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis. However, due to high similarity in the active sites of the four members (Jak1, Jak2, Jak3, and Tyk2), developing selective inhibitors within this family is challenging. We have designed and characterized substituted, tricyclic Jak3 inhibitors that selectively avoid inhibition of the other JAKs. This is accomplished through a covalent interaction between an inhibitor containing a terminal electrophile and an active site cysteine (Cys-909). We found that these ATP competitive compounds are irreversible inhibitors of Jak3 enzyme activity in vitro. They possess high selectivity against other kinases and can potently (IC50 < 100 nm) inhibit Jak3 activity in cell-based assays. These results suggest irreversible inhibitors of this class may be useful selective agents, both as tools to probe Jak3 biology and potentially as therapies for autoimmune diseases. PMID:25552479

  9. Tricyclic Covalent Inhibitors Selectively Target Jak3 through an Active Site Thiol*

    PubMed Central

    Goedken, Eric R.; Argiriadi, Maria A.; Banach, David L.; Fiamengo, Bryan A.; Foley, Sage E.; Frank, Kristine E.; George, Jonathan S.; Harris, Christopher M.; Hobson, Adrian D.; Ihle, David C.; Marcotte, Douglas; Merta, Philip J.; Michalak, Mark E.; Murdock, Sara E.; Tomlinson, Medha J.; Voss, Jeffrey W.

    2015-01-01

    The action of Janus kinases (JAKs) is required for multiple cytokine signaling pathways, and as such, JAK inhibitors hold promise for treatment of autoimmune disorders, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis. However, due to high similarity in the active sites of the four members (Jak1, Jak2, Jak3, and Tyk2), developing selective inhibitors within this family is challenging. We have designed and characterized substituted, tricyclic Jak3 inhibitors that selectively avoid inhibition of the other JAKs. This is accomplished through a covalent interaction between an inhibitor containing a terminal electrophile and an active site cysteine (Cys-909). We found that these ATP competitive compounds are irreversible inhibitors of Jak3 enzyme activity in vitro. They possess high selectivity against other kinases and can potently (IC50 < 100 nm) inhibit Jak3 activity in cell-based assays. These results suggest irreversible inhibitors of this class may be useful selective agents, both as tools to probe Jak3 biology and potentially as therapies for autoimmune diseases. PMID:25552479

  10. Structures of the Four Subfamilies of Phosphodiesterase-4 Provide Insight into the Selectivity of Their Inhibitors

    SciTech Connect

    Wang, H.; Peng, M; Chen , Y; Geng, J; Robinson, H; Houslay , M; Cai, J; Ke, H

    2007-01-01

    PDE4 (phosphodiesterase-4)-selective inhibitors have attracted much attention as potential therapeutics for the treatment of both depression and major inflammatory diseases, but their practical application has been compromised by side effects. A possible cause for the side effects is that current PDE4-selective inhibitors similarly inhibit isoforms from all four PDE4 subfamilies. The development of PDE4 subfamily-selective inhibitors has been hampered by a lack of structural information. In the present study, we rectify this by providing the crystal structures of the catalytic domains of PDE4A, PDE4B and PDE4D in complex with the PDE4 inhibitor NVP 4-[8-(3-nitrophenyl)-[1,7]naphthyridin-6-yl]benzoic acid as well as the unliganded PDE4C structure. NVP binds in the same conformation to the deep cAMP substrate pocket and interacts with the same residues in each instance. However, detailed structural comparison reveals significant conformational differences. Although the active sites of PDE4B and PDE4D are mostly comparable, PDE4A shows significant displacements of the residues next to the invariant glutamine residue that is critical for substrate and inhibitor binding. PDE4C appears to be more distal from other PDE4 subfamilies, with certain key residues being disordered. Our analyses provide the first structural basis for the development of PDE4 subfamily-selective inhibitors.

  11. Selective COX-2 Inhibitors: A Review of Their Structure-Activity Relationships

    PubMed Central

    Zarghi, Afshin; Arfaei, Sara

    2011-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the competitive inhibitors of cyclooxygenase (COX), the enzyme which mediates the bioconversion of arachidonic acid to inflammatory prostaglandins (PGs). Their use is associated with the side effects such as gastrointestinal and renal toxicity. The therapeutic anti-inflammatory action of NSAIDs is produced by the inhibition of COX-2, while the undesired side effects arise from inhibition of COX-1 activity. Thus, it was though that more selective COX-2 inhibitors would have reduced side effects. Based upon a number of selective COX-2 inhibitors (rofecoxib, celecoxib, valdecoxibetc.) were developed as safer NSAIDs with improved gastric safety profile. However, the recent market removal of some COXIBs such as rofecoxib due to its adverse cardiovascular side effects clearly encourages the researchers to explore and evaluate alternative templates with COX-2 inhibitory activity. Recognition of new avenues for selective COX-2 inhibitors in cancer chemotherapy and neurological diseases such as Parkinson and Alzheimer’s diseases still continues to attract investigations on the development of COX-2 inhibitors. This review highlights the various structural classes of selective COX-2 inhibitors with special emphasis on their structure-activity relationships. PMID:24250402

  12. Combined Effects of Cyclooxygenase-1 and Cyclooxygenase-2 Selective Inhibitors on Ovarian Carcinoma in Vivo

    PubMed Central

    Li, Wei; Wang, Jie; Jiang, Hong-Ru; Xu, Xiao-Li; Zhang, Jun; Liu, Mei-Lin; Zhai, Ling-Yun

    2011-01-01

    The present study was designed to investigate the combined effects of cyclooxygenase (COX)-1 and COX-2 selective inhibitors on human ovarian SKOV-3 carcinoma cells xenograft-bearing mice. The animals were treated with 3 mg/kg SC-560 (a COX-1 selective inhibitor) alone, 25 mg/kg celecoxib (a COX-2 selective inhibitor) alone, or SC-560/celecoxib by gavage, twice a day for three weeks. To test the mechanism of inhibition of tumor growth by COX selective inhibitors, the index of proliferating cells in tumor tissues was determined by immunostaining and the index of apoptotic cells by the terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. The inhibitory rate on tumor growth in the combination group was 35.54% which is significant statistically compared with that of the control group (P < 0.05). In the combination group, the index of cell proliferation and apoptosis were 12.40% and 51.03% respectively, which are significant statistically compared with those of the control group (22.56%, 19.07%, all P < 0.05). These studies indicate that synergism between two COX inhibitors and inhibitor combination treatment has particular potential for chemoprevention of ovarian cancer growth. PMID:21340007

  13. Design, Synthesis, and Optimization of Novel Epoxide Incorporating Peptidomimetics as Selective Calpain Inhibitors

    PubMed Central

    Schiefer, Isaac T.; Tapadar, Subhasish; Litosh, Vladislav; Siklos, Marton; Scism, Rob; Wijewickrama, Gihani T.; Chandrasena, Esala P.; Sinha, Vaishali; Tavassoli, Ehsan; Brunsteiner, Michael; Fa′, Mauro; Arancio, Ottavio; Petukhov, Pavel; Thatcher, Gregory R. J.

    2014-01-01

    Hyperactivation of the calcium-dependent cysteine protease, calpain-1 (Cal1), is implicated as a primary or secondary pathological event in a wide range of illnesses, and in neurodegenerative states, including Alzheimer’s disease (AD). E-64 is an epoxide-containing natural product identified as a potent non-selective, calpain inhibitor, with demonstrated efficacy in animal models of AD. Using E-64 as a lead, three successive generations of calpain inhibitors were developed using computationally assisted design to increase selectivity for Cal1. First generation analogs were potent inhibitors, effecting covalent modification of recombinant Cal1 catalytic domain (Cal1cat), demonstrated using LC-MS/MS. Refinement yielded 2nd generation inhibitors with improved selectivity. Further library expansion and ligand refinement gave three Cal1 inhibitors, one of which was designed as an activity-based protein profiling probe. These were determined to be irreversible and selective inhibitors by kinetic studies comparing full length Cal1 with the general cysteine protease, papain. PMID:23834438

  14. Fragment-Based Discovery of Potent and Selective DDR1/2 Inhibitors.

    PubMed

    Murray, Christopher W; Berdini, Valerio; Buck, Ildiko M; Carr, Maria E; Cleasby, Anne; Coyle, Joseph E; Curry, Jayne E; Day, James E H; Day, Phillip J; Hearn, Keisha; Iqbal, Aman; Lee, Lydia Y W; Martins, Vanessa; Mortenson, Paul N; Munck, Joanne M; Page, Lee W; Patel, Sahil; Roomans, Susan; Smith, Kirsten; Tamanini, Emiliano; Saxty, Gordon

    2015-07-01

    The DDR1 and DDR2 receptor tyrosine kinases are activated by extracellular collagen and have been implicated in a number of human diseases including cancer. We performed a fragment-based screen against DDR1 and identified fragments that bound either at the hinge or in the back pocket associated with the DFG-out conformation of the kinase. Modeling based on crystal structures of potent kinase inhibitors facilitated the "back-to-front" design of potent DDR1/2 inhibitors that incorporated one of the DFG-out fragments. Further optimization led to low nanomolar, orally bioavailable inhibitors that were selective for DDR1 and DDR2. The inhibitors were shown to potently inhibit DDR2 activity in cells but in contrast to unselective inhibitors such as dasatinib, they did not inhibit proliferation of mutant DDR2 lung SCC cell lines. PMID:26191369

  15. Chemoproteomics-Enabled Discovery of a Potent and Selective Inhibitor of the DNA Repair Protein MGMT.

    PubMed

    Wang, Chao; Abegg, Daniel; Hoch, Dominic G; Adibekian, Alexander

    2016-02-18

    We present a novel chemical scaffold for cysteine-reactive covalent inhibitors. Chloromethyl triazoles (CMTs) are readily accessed in only two chemical steps, thus enabling the rapid optimization of the pharmacological properties of these inhibitors. We demonstrate the tunability of the CMTs towards a specific biological target by synthesizing AA-CW236 as the first potent non-pseudosubstrate inhibitor of the O(6) -alkylguanine DNA methyltransferase (MGMT), a protein of major clinical significance for the treatment of several severe cancer forms. Using quantitative proteomics profiling techniques, we show that AA-CW236 exhibits a high degree of selectivity towards MGMT. Finally, we validate the effectiveness of our MGMT inhibitor in combination with the DNA alkylating drug temozolomide in breast and colon cancer cells by fluorescence imaging and a cell-viability assay. Our results may open a new avenue towards the development of a clinically approved MGMT inhibitor. PMID:26798972

  16. Optimization of a Dibenzodiazepine Hit to a Potent and Selective Allosteric PAK1 Inhibitor

    PubMed Central

    2015-01-01

    The discovery of inhibitors targeting novel allosteric kinase sites is very challenging. Such compounds, however, once identified could offer exquisite levels of selectivity across the kinome. Herein we report our structure-based optimization strategy of a dibenzodiazepine hit 1, discovered in a fragment-based screen, yielding highly potent and selective inhibitors of PAK1 such as 2 and 3. Compound 2 was cocrystallized with PAK1 to confirm binding to an allosteric site and to reveal novel key interactions. Compound 3 modulated PAK1 at the cellular level and due to its selectivity enabled valuable research to interrogate biological functions of the PAK1 kinase. PMID:26191365

  17. Selective Serotonin–norepinephrine Reuptake Inhibitors-induced Takotsubo Cardiomyopathy

    PubMed Central

    Vasudev, Rahul; Rampal, Upamanyu; Patel, Hiten; Patel, Kunal; Bikkina, Mahesh; Shamoon, Fayez

    2016-01-01

    Context: Takotsubo translates to “octopus pot” in Japanese. Takotsubo cardiomyopathy (TTC) is characterized by a transient regional systolic dysfunction of the left ventricle. Catecholamine excess is the one most studied and favored theories explaining the pathophysiology of TTC. Case Report: We present the case of a 52-year-old Hispanic female admitted for venlafaxine-induced TTC with a review literature on all the cases of Serotonin–norepinephrine reuptake inhibitors (SNRI)-associated TTC published so far. Conclusion: SNRI inhibit the reuptake of catecholamines into the presynaptic neuron, resulting in a net gain in the concentration of epinephrine and serotonin in the neuronal synapses and causing iatrogenic catecholamine excess, ultimately leading to TTC. PMID:27583240

  18. Cysteine proteases as therapeutic targets: does selectivity matter? A systematic review of calpain and cathepsin inhibitors

    PubMed Central

    Siklos, Marton; BenAissa, Manel; Thatcher, Gregory R.J.

    2015-01-01

    Cysteine proteases continue to provide validated targets for treatment of human diseases. In neurodegenerative disorders, multiple cysteine proteases provide targets for enzyme inhibitors, notably caspases, calpains, and cathepsins. The reactive, active-site cysteine provides specificity for many inhibitor designs over other families of proteases, such as aspartate and serine; however, a) inhibitor strategies often use covalent enzyme modification, and b) obtaining selectivity within families of cysteine proteases and their isozymes is problematic. This review provides a general update on strategies for cysteine protease inhibitor design and a focus on cathepsin B and calpain 1 as drug targets for neurodegenerative disorders; the latter focus providing an interesting query for the contemporary assumptions that irreversible, covalent protein modification and low selectivity are anathema to therapeutic safety and efficacy. PMID:26713267

  19. Selective inhibitors of Cyclin-G associated kinase (GAK) as anti-HCV agents

    PubMed Central

    Kovackova, Sona; Chang, Lei; Bekerman, Elena; Neveu, Gregory; Barouch-Bentov, Rina; Chaikuad, Apirat; Heroven, Christina; Šála, Michal; De Jonghe, Steven; Knapp, Stefan; Einav, Shirit; Herdewijn, Piet

    2015-01-01

    Cyclin-G associated kinase (GAK) emerged as a promising drug target for the treatment of viral infections. However, no potent and selective GAK inhibitors have been reported in the literature to date. This paper describes the discovery of isothiazolo[5,4-b]pyridines as selective GAK inhibitors, with the most potent congeners displaying low nanomolar binding affinity for GAK. Co-crystallization experiments revealed that these compounds behaved as classic type I ATP-competitive kinase inhibitors. In addition, we have demonstrated that these compounds exhibit a potent activity against hepatitis C virus (HCV) by inhibiting two temporally distinct steps in the HCV lifecycle (i.e. viral entry and assembly). Hence, these GAK inhibitors represent chemical probes to study GAK function in different disease areas where GAK has been implicated (including viral infection, cancer and Parkinson's disease). PMID:25822739

  20. Selective Inhibitors of Fibroblast Activation Protein (FAP) with a (4-Quinolinoyl)-glycyl-2-cyanopyrrolidine Scaffold.

    PubMed

    Jansen, Koen; Heirbaut, Leen; Cheng, Jonathan D; Joossens, Jurgen; Ryabtsova, Oxana; Cos, Paul; Maes, Louis; Lambeir, Anne-Marie; De Meester, Ingrid; Augustyns, Koen; Van der Veken, Pieter

    2013-05-01

    Fibroblast activation protein (FAP) is a serine protease that is generally accepted to play an important role in tumor growth and other diseases involving tissue remodeling. Currently there are no FAP inhibitors with reported selectivity toward both the closely related dipeptidyl peptidases (DPPs) and prolyl oligopeptidase (PREP). We present the discovery of a new class of FAP inhibitors with a N-(4-quinolinoyl)-Gly-(2-cyanopyrrolidine) scaffold. We have explored the effects of substituting the quinoline ring and varying the position of its sp(2) hybridized nitrogen atom. The most promising inhibitors combined low nanomolar FAP inhibition and high selectivity indices (>10(3)) with respect to both the DPPs and PREP. Preliminary experiments on a representative inhibitor demonstrate that plasma stability, kinetic solubility, and log D of this class of compounds can be expected to be satisfactory. PMID:24900696

  1. Sulfated Pentagalloylglucoside is a Potent, Allosteric, and Selective Inhibitor of Factor XIa

    PubMed Central

    Al-Horani, Rami A.; Ponnusamy, Pooja; Mehta, Akul Y.; Gailani, David; Desai, Umesh R.

    2013-01-01

    Inhibition of factor XIa (FXIa) is a novel paradigm for developing anticoagulants without major bleeding consequences. We present the discovery of sulfated pentagalloylglucoside (6) as a highly selective inhibitor of human FXIa. Biochemical screening of a focused library led to the identification of 6, a sulfated aromatic mimetic of heparin. Inhibitor 6 displayed a potency of 551 nM against FXIa, which was at least 200-fold more selective than other relevant enzymes. It also prevented activation of factor IX and prolonged human plasma and whole blood clotting. Inhibitor 6 reduced VMAX of FXIa hydrolysis of chromogenic substrate without affecting the KM suggesting an allosteric mechanism. Competitive studies showed that 6 bound in the heparin-binding site of FXIa. No allosteric small molecule has been discovered to date that exhibits equivalent potency against FXIa. Inhibitor 6 is expected to open up a major route to allosteric FXIa anticoagulants with clinical relevance. PMID:23316863

  2. Identification and Structure-Function Analysis of Subfamily Selective G Protein-Coupled Receptor Kinase Inhibitors

    SciTech Connect

    Homan, Kristoff T.; Larimore, Kelly M.; Elkins, Jonathan M.; Szklarz, Marta; Knapp, Stefan; Tesmer, John J.G.

    2015-02-13

    Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson’s disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can be clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors.

  3. Identification and structure-function analysis of subfamily selective G protein-coupled receptor kinase inhibitors.

    PubMed

    Homan, Kristoff T; Larimore, Kelly M; Elkins, Jonathan M; Szklarz, Marta; Knapp, Stefan; Tesmer, John J G

    2015-01-16

    Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson's disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can be clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors. PMID:25238254

  4. PI3K isoform-selective inhibitors: next-generation targeted cancer therapies

    PubMed Central

    Wang, Xiang; Ding, Jian; Meng, Ling-hua

    2015-01-01

    The pivotal roles of phosphatidylinositol 3-kinases (PI3Ks) in human cancers have inspired active development of small molecules to inhibit these lipid kinases. However, the first-generation pan-PI3K and dual-PI3K/mTOR inhibitors have encountered problems in clinical trials, with limited efficacies as a monotherapeutic agent as well as a relatively high rate of side effects. It is increasingly recognized that different PI3K isoforms play non-redundant roles in particular tumor types, which has prompted the development of isoform-selective inhibitors for pre-selected patients with the aim for improving efficacy while decreasing undesirable side effects. The success of PI3K isoform-selective inhibitors is represented by CAL101 (Idelalisib), a first-in-class PI3Kδ-selective small-molecule inhibitor that has been approved by the FDA for the treatment of chronic lymphocytic leukemia, indolent B-cell non-Hodgkin's lymphoma and relapsed small lymphocytic lymphoma. Inhibitors targeting other PI3K isoforms are also being extensively developed. This review focuses on the recent progress in development of PI3K isoform-selective inhibitors for cancer therapy. A deeper understanding of the action modes of novel PI3K isoform-selective inhibitors will provide valuable information to further validate the concept of targeting specific PI3K isoforms, while the identification of biomarkers to stratify patients who are likely to benefit from the therapy will be essential for the success of these agents. PMID:26364801

  5. PI3K isoform-selective inhibitors: next-generation targeted cancer therapies.

    PubMed

    Wang, Xiang; Ding, Jian; Meng, Ling-hua

    2015-10-01

    The pivotal roles of phosphatidylinositol 3-kinases (PI3Ks) in human cancers have inspired active development of small molecules to inhibit these lipid kinases. However, the first-generation pan-PI3K and dual-PI3K/mTOR inhibitors have encountered problems in clinical trials, with limited efficacies as a monotherapeutic agent as well as a relatively high rate of side effects. It is increasingly recognized that different PI3K isoforms play non-redundant roles in particular tumor types, which has prompted the development of isoform-selective inhibitors for pre-selected patients with the aim for improving efficacy while decreasing undesirable side effects. The success of PI3K isoform-selective inhibitors is represented by CAL101 (Idelalisib), a first-in-class PI3Kδ-selective small-molecule inhibitor that has been approved by the FDA for the treatment of chronic lymphocytic leukemia, indolent B-cell non-Hodgkin's lymphoma and relapsed small lymphocytic lymphoma. Inhibitors targeting other PI3K isoforms are also being extensively developed. This review focuses on the recent progress in development of PI3K isoform-selective inhibitors for cancer therapy. A deeper understanding of the action modes of novel PI3K isoform-selective inhibitors will provide valuable information to further validate the concept of targeting specific PI3K isoforms, while the identification of biomarkers to stratify patients who are likely to benefit from the therapy will be essential for the success of these agents. PMID:26364801

  6. Discovery of potent and selective spiroindolinone MDM2 inhibitor, RO8994, for cancer therapy.

    PubMed

    Zhang, Zhuming; Ding, Qingjie; Liu, Jin-Jun; Zhang, Jing; Jiang, Nan; Chu, Xin-Jie; Bartkovitz, David; Luk, Kin-Chun; Janson, Cheryl; Tovar, Christian; Filipovic, Zoran M; Higgins, Brian; Glenn, Kelli; Packman, Kathryn; Vassilev, Lyubomir T; Graves, Bradford

    2014-08-01

    The field of small-molecule inhibitors of protein-protein interactions is rapidly advancing and the specific area of inhibitors of the p53/MDM2 interaction is a prime example. Several groups have published on this topic and multiple compounds are in various stages of clinical development. Building on the strength of the discovery of RG7112, a Nutlin imidazoline-based compound, and RG7388, a pyrrolidine-based compound, we have developed additional scaffolds that provide opportunities for future development. Here, we report the discovery and optimization of a highly potent and selective series of spiroindolinone small-molecule MDM2 inhibitors, culminating in RO8994. PMID:24997575

  7. Discovery of RG7388, a potent and selective p53-MDM2 inhibitor in clinical development.

    PubMed

    Ding, Qingjie; Zhang, Zhuming; Liu, Jin-Jun; Jiang, Nan; Zhang, Jing; Ross, Tina M; Chu, Xin-Jie; Bartkovitz, David; Podlaski, Frank; Janson, Cheryl; Tovar, Christian; Filipovic, Zoran M; Higgins, Brian; Glenn, Kelli; Packman, Kathryn; Vassilev, Lyubomir T; Graves, Bradford

    2013-07-25

    Restoration of p53 activity by inhibition of the p53-MDM2 interaction has been considered an attractive approach for cancer treatment. However, the hydrophobic protein-protein interaction surface represents a significant challenge for the development of small-molecule inhibitors with desirable pharmacological profiles. RG7112 was the first small-molecule p53-MDM2 inhibitor in clinical development. Here, we report the discovery and characterization of a second generation clinical MDM2 inhibitor, RG7388, with superior potency and selectivity. PMID:23808545

  8. Corrosion inhibitor selection for arctic and subsea high-velocity flowlines

    SciTech Connect

    Dougherty, J.A.

    2000-03-01

    Qualifying corrosion inhibitors for use in high-velocity multiphase flowlines in arctic or subsea environments is discussed. The criteria include high-velocity flow loop corrosion tests, pumpability through 0.125-in. (0.318-cm) capillary at low temperatures, compatibility with nylon 11, emulsion tendency testing, and partitioning characteristics. Laboratory and field data show the importance of using these criteria for inhibitor selection.

  9. Structural insight into selectivity and resistance profiles of ROS1 tyrosine kinase inhibitors

    PubMed Central

    Davare, Monika A.; Vellore, Nadeem A.; Wagner, Jacob P.; Eide, Christopher A.; Goodman, James R.; Drilon, Alexander; Deininger, Michael W.; O’Hare, Thomas; Druker, Brian J.

    2015-01-01

    Oncogenic ROS1 fusion proteins are molecular drivers in multiple malignancies, including a subset of non-small cell lung cancer (NSCLC). The phylogenetic proximity of the ROS1 and anaplastic lymphoma kinase (ALK) catalytic domains led to the clinical repurposing of the Food and Drug Administration (FDA)-approved ALK inhibitor crizotinib as a ROS1 inhibitor. Despite the antitumor activity of crizotinib observed in both ROS1- and ALK-rearranged NSCLC patients, resistance due to acquisition of ROS1 or ALK kinase domain mutations has been observed clinically, spurring the development of second-generation inhibitors. Here, we profile the sensitivity and selectivity of seven ROS1 and/or ALK inhibitors at various levels of clinical development. In contrast to crizotinib’s dual ROS1/ALK activity, cabozantinib (XL-184) and its structural analog foretinib (XL-880) demonstrate a striking selectivity for ROS1 over ALK. Molecular dynamics simulation studies reveal structural features that distinguish the ROS1 and ALK kinase domains and contribute to differences in binding site and kinase selectivity of the inhibitors tested. Cell-based resistance profiling studies demonstrate that the ROS1-selective inhibitors retain efficacy against the recently reported CD74-ROS1G2032R mutant whereas the dual ROS1/ALK inhibitors are ineffective. Taken together, inhibitor profiling and stringent characterization of the structure–function differences between the ROS1 and ALK kinase domains will facilitate future rational drug design for ROS1- and ALK-driven NSCLC and other malignancies. PMID:26372962

  10. Enzymatic Studies of Isoflavonoids as Selective and Potent Inhibitors of Human Leukocyte 5-Lipo-Oxygenase.

    PubMed

    Mascayano, Carolina; Espinosa, Victoria; Sepúlveda-Boza, Silvia; Hoobler, Eric K; Perry, Steve; Diaz, Giovanni; Holman, Theodore R

    2015-07-01

    Continuing our search to find more potent and selective 5-LOX inhibitors, we present now the enzymatic evaluation of seventeen isoflavones (IR) and nine isoflavans (HIR), and their in vitro and in cellulo potency against human leukocyte 5-LOX. Of the 26 compounds tested, 10 isoflavones and 9 isoflavans possessed micromolar potency, but only three were selective against 5-LOX (IR-2, HIR-303, and HIR-309), with IC50 values at least 10 times lower than those of 12-LOX, 15-LOX-1, and 15-LOX-2. Of these three, IR-2 (6,7-dihydroxy-4-methoxy-isoflavone, known as texasin) was the most selective 5-LOX inhibitor, with over 80-fold potency difference compared with other isozymes; Steered Molecular Dynamics (SMD) studies supported these findings. The presence of the catechol group on ring A (6,7-dihydroxy versus 7,8-dihydroxy) correlated with their biological activity, but the reduction of ring C, converting the isoflavones to isoflavans, and the substituent positions on ring B did not affect their potency against 5-LOX. Two of the most potent/selective inhibitors (HIR-303 and HIR-309) were reductive inhibitors and were potent against 5-LOX in human whole blood, indicating that isoflavans can be potent and selective inhibitors against human leukocyte 5-LOX in vitro and in cellulo. PMID:25359714

  11. Molecular Mechanism of Selectivity among G Protein-Coupled Receptor Kinase 2 Inhibitors

    SciTech Connect

    Thal, David M.; Yeow, Raymond Y.; Schoenau, Christian; Huber, Jochen; Tesmer, John J.G.

    2012-07-11

    G protein-coupled receptors (GPCRs) are key regulators of cell physiology and control processes ranging from glucose homeostasis to contractility of the heart. A major mechanism for the desensitization of activated GPCRs is their phosphorylation by GPCR kinases (GRKs). Overexpression of GRK2 is strongly linked to heart failure, and GRK2 has long been considered a pharmaceutical target for the treatment of cardiovascular disease. Several lead compounds developed by Takeda Pharmaceuticals show high selectivity for GRK2 and therapeutic potential for the treatment of heart failure. To understand how these drugs achieve their selectivity, we determined crystal structures of the bovine GRK2-G{beta}{gamma} complex in the presence of two of these inhibitors. Comparison with the apoGRK2-G{beta}{gamma} structure demonstrates that the compounds bind in the kinase active site in a manner similar to that of the AGC kinase inhibitor balanol. Both balanol and the Takeda compounds induce a slight closure of the kinase domain, the degree of which correlates with the potencies of the inhibitors. Based on our crystal structures and homology modeling, we identified five amino acids surrounding the inhibitor binding site that we hypothesized could contribute to inhibitor selectivity. However, our results indicate that these residues are not major determinants of selectivity among GRK subfamilies. Rather, selectivity is achieved by the stabilization of a unique inactive conformation of the GRK2 kinase domain.

  12. Virtual screening of selective multitarget kinase inhibitors by combinatorial support vector machines.

    PubMed

    Ma, X H; Wang, R; Tan, C Y; Jiang, Y Y; Lu, T; Rao, H B; Li, X Y; Go, M L; Low, B C; Chen, Y Z

    2010-10-01

    Multitarget agents have been increasingly explored for enhancing efficacy and reducing countertarget activities and toxicities. Efficient virtual screening (VS) tools for searching selective multitarget agents are desired. Combinatorial support vector machines (C-SVM) were tested as VS tools for searching dual-inhibitors of 11 combinations of 9 anticancer kinase targets (EGFR, VEGFR, PDGFR, Src, FGFR, Lck, CDK1, CDK2, GSK3). C-SVM trained on 233-1,316 non-dual-inhibitors correctly identified 26.8%-57.3% (majority >36%) of the 56-230 intra-kinase-group dual-inhibitors (equivalent to the 50-70% yields of two independent individual target VS tools), and 12.2% of the 41 inter-kinase-group dual-inhibitors. C-SVM were fairly selective in misidentifying as dual-inhibitors 3.7%-48.1% (majority <20%) of the 233-1,316 non-dual-inhibitors of the same kinase pairs and 0.98%-4.77% of the 3,971-5,180 inhibitors of other kinases. C-SVM produced low false-hit rates in misidentifying as dual-inhibitors 1,746-4,817 (0.013%-0.036%) of the 13.56 M PubChem compounds, 12-175 (0.007%-0.104%) of the 168 K MDDR compounds, and 0-84 (0.0%-2.9%) of the 19,495-38,483 MDDR compounds similar to the known dual-inhibitors. C-SVM was compared to other VS methods Surflex-Dock, DOCK Blaster, kNN and PNN against the same sets of kinase inhibitors and the full set or subset of the 1.02 M Zinc clean-leads data set. C-SVM produced comparable dual-inhibitor yields, slightly better false-hit rates for kinase inhibitors, and significantly lower false-hit rates for the Zinc clean-leads data set. Combinatorial SVM showed promising potential for searching selective multitarget agents against intra-kinase-group kinases without explicit knowledge of multitarget agents. PMID:20712327

  13. Catalytic site remodelling of the DOT1L methyltransferase by selective inhibitors

    SciTech Connect

    Yu, Wenyu; Chory, Emma J.; Wernimont, Amy K.; Tempel, Wolfram; Scopton, Alex; Federation, Alexander; Marineau, Jason J.; Qi, Jun; Barsyte-Lovejoy, Dalia; Yi, Joanna; Marcellus, Richard; Iacob, Roxana E.; Engen, John R.; Griffin, Carly; Aman, Ahmed; Wienholds, Erno; Li, Fengling; Pineda, Javier; Estiu, Guillermina; Shatseva, Tatiana; Hajian, Taraneh; Al-awar, Rima; Dick, John E.; Vedadi, Masoud; Brown, Peter J.; Arrowsmith, Cheryl H.; Bradner, James E.; Schapira, Matthieu

    2012-12-18

    Selective inhibition of protein methyltransferases is a promising new approach to drug discovery. An attractive strategy towards this goal is the development of compounds that selectively inhibit binding of the cofactor, S-adenosylmethionine, within specific protein methyltransferases. Here we report the three-dimensional structure of the protein methyltransferase DOT1L bound toEPZ004777, the first S-adenosylmethionine-competitive inhibitor of a protein methyltransferase with in vivo efficacy. This structure and those of four new analogues reveal remodelling of the catalytic site. EPZ004777 and a brominated analogue, SGC0946, inhibit DOT1L in vitro and selectively kill mixed lineage leukaemia cells, in which DOT1L is aberrantly localized via interaction with an oncogenic MLL fusion protein. These data provide important new insight into mechanisms of cell-active S-adenosylmethionine-competitive protein methyltransferase inhibitors, and establish a foundation for the further development of drug-like inhibitors of DOT1L for cancer therapy.

  14. High-throughput screening identifies artesunate as selective inhibitor of cancer stemness: Involvement of mitochondrial metabolism.

    PubMed

    Subedi, Amit; Futamura, Yushi; Nishi, Mayuko; Ryo, Akihide; Watanabe, Nobumoto; Osada, Hiroyuki

    2016-09-01

    Cancer stem cells (CSCs) have robust systems to maintain cancer stemness and drug resistance. Thus, targeting such robust systems instead of focusing on individual signaling pathways should be the approach allowing the identification of selective CSC inhibitors. Here, we used the alkaline phosphatase (ALP) assay to identify inhibitors for cancer stemness in induced cancer stem-like (iCSCL) cells. We screened several compounds from natural product chemical library and evaluated hit compounds for their efficacy on cancer stemness in iCSCL tumorspheres. We identified artesunate, an antimalarial drug, as a selective inhibitor of cancer stemness. Artesunate induced mitochondrial dysfunction that selectively inhibited cancer stemness of iCSCL cells, indicating an essential role of mitochondrial metabolism in cancer stemness. PMID:27363336

  15. A selective inhibitor of the UFM1-activating enzyme, UBA5.

    PubMed

    da Silva, Sara R; Paiva, Stacey-Lynn; Bancerz, Matthew; Geletu, Mulu; Lewis, Andrew M; Chen, Jijun; Cai, Yafei; Lukkarila, Julie L; Li, Honglin; Gunning, Patrick T

    2016-09-15

    Protein conjugation with ubiquitin and ubiquitin-like small molecules, such as UFM1, is important for promoting cancer cell survival and proliferation. Herein, the development of the first selective micromolar inhibitor of the UBA5 E1 enzyme that initiates UFM1 protein conjugation is described. This organometallic inhibitor incorporates adenosine and zinc(II)cyclen within its core scaffold and inhibits UBA5 noncompetitively and selectively over other E1 enzymes and a panel of human kinases. Furthermore, this compound selectively impedes the cellular proliferation (above 50μM) of cancer cells containing higher levels of UBA5. This inhibitor may be used to further probe the intracellular role of the UFM1 pathway in disease progression. PMID:27520940

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

    PubMed

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

    2016-06-30

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

  17. Nonhydrolyzable ATP analogues as selective inhibitors of human NPP1: a combined computational/experimental study.

    PubMed

    Lecka, Joanna; Ben-David, Gal; Simhaev, Luba; Eliahu, Shay; Oscar, Jocelyn; Luyindula, Patrick; Pelletier, Julie; Fischer, Bilha; Senderowitz, Hanoch; Sévigny, Jean

    2013-11-14

    Elevated nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) activity is implicated in health disorders including pathological calcification. Specific NPP1 inhibitors would therefore be valuable for studying this enzyme and as potential therapeutic agents. Here we present a combined computational/experimental study characterizing 13 nonhydrolyzable ATP analogues as selective human NPP1 inhibitors. All analogues at 100 μM inhibited (66-99%) the hydrolysis of pnp-TMP by both recombinant NPP1 and cell surface NPP1 activity of osteocarcinoma (HTB-85) cells. These analogues only slightly altered the activity of other ectonucleotidases, NPP3 and NTPDases. The Ki,app values of the seven most potent and selective inhibitors were in the range of 0.5-56 μM, all with mixed type inhibition, predominantly competitive. Those molecules were docked into a newly developed homology model of human NPP1. All adopted ATP-like binding modes, suggesting competitive inhibition with the endogenous ligand. NPP1 selectivity versus NPP3 could be explained in terms of the electrostatic potential of the two proteins that of NPP1 favoring negatively charged ligands. Inhibitor 2 that had the lowest Ki,app (0.5 μM) was also inactive toward P2Y receptors. Overall, analogue 2 is the most potent and selective NPP1 inhibitor described so far. PMID:24083941

  18. Free energy calculation provides insight into the action mechanism of selective PARP-1 inhibitor.

    PubMed

    Cao, Ran

    2016-04-01

    Selective poly (ADP-ribose) polymerase (PARP)-1 inhibitor represents promising therapy against cancers with a good balance between efficacy and safety. Owing to the conserved structure between PARP-1 and PARP-2, most of the clinical and experimental drugs show equivalent inhibition against both targets. Most recently, it's disclosed a highly selective PARP-1 inhibitor (NMS-P118) with promising pharmacokinetic properties. Herein, we combined molecular simulation with free energy calculation to gain insights into the selective mechanism of NMS-P118. Our results suggest the reduction of binding affinity for PARP-2 is attributed to the unfavorable conformational change of protein, which is accompanied by a significant energy penalty. Alanine-scanning mutagenesis study further reveals the important role for a tyrosine residue of donor loop (Tyr889(PARP-1) and Tyr455(PARP-2)) in contributing to the ligand selectivity. Retrospective structural analysis indicates the ligand-induced movement of Tyr455(PARP-2) disrupts the intra-molecule hydrogen bonding network, which partially accounts for the "high-energy" protein conformation in the presence of NMS-P118. Interestingly, such effect isn't observed in other non-selective PARP inhibitors including BMN673 and A861695, which validates the computational prediction. Our work provides energetic insight into the subtle variations in the crystal structures and could facilitate rational design of new selective PARP inhibitor. PMID:26969680

  19. Electrocardiographic effects of class 1 selective histone deacetylase inhibitor romidepsin

    PubMed Central

    Sager, Philip T; Balser, Barbara; Wolfson, Julie; Nichols, Jean; Pilot, Richard; Jones, Suzanne; Burris, Howard A

    2015-01-01

    Romidepsin is a histone deacetylase inhibitor approved by the FDA for the treatment of patients with cutaneous or peripheral T-cell lymphoma who have received prior systemic therapy. The objective of this analysis was to evaluate the potential QTc effects of romidepsin. Patients with advanced malignancy received 4-h infusions of 14 mg/m2 romidepsin on days 1, 8, and 15 of a 28-day cycle. In cycle 2, a subset of patients received 1-h infusions of 8–12 mg/m2 romidepsin. Patients were administered antiemetics before each romidepsin dose and electrolyte supplementation as needed. Electrocardiogram readings were performed prior to antiemetic administration, prior to romidepsin administration, and at specified time points over the subsequent 24 h. Romidepsin exposure and heart rate were also assessed. In the electrocardiogram-evaluable population, 26 patients received romidepsin at 14 mg/m2 over 4 h. The maximum mean increases from the preantiemetic baseline for QTcF and heart rate were 10.1 msec (upper 90% CI, 14.5 msec) and 18.2 beats per minute, respectively. No patient in this study had an absolute QTcF value >450 msec and only one patient had an increase from the preantiemetic baseline of >60 msec. There was a mild reduction in the PR interval and no meaningful changes in the QRS interval. Despite the use of QT-prolonging antiemetics, treatment with romidepsin did not markedly prolong the QTc interval through 24 h. Increases in calculated QTc may have been exaggerated as a consequence of transient increases in heart rate. PMID:25914207

  20. Selective serotonin reuptake inhibitor utilization patterns: consistency across research designs.

    PubMed

    Hutchins, D S; Klein, E G; Signa, W F; Young, C H; Gregor, K J

    1998-01-01

    We examined the impact of commonly applied selection criteria on the ability of patients who are initiating antidepressant therapy to reach a stable pattern, which was defined as receipt of only the initial agent at the initial dose for 90 or more consecutive days. Patients in a large US prescription database who initiated fluoxetine, paroxetine, or sertraline therapy between February and April of 1995 were categorized as with (typical design) and without (relaxed design) commonly applied selection criteria. The percentage of patients achieving a stable pattern was then determined. We found that this percentage was significantly higher with the relaxed design (typical, 28.8%; relaxed, 32.4%) and for patients initiating fluoxetine therapy (>5.5% higher than for those initiating paroxetine or sertraline therapy). The results for fluoxetine were consistent across designs, whereas comparisons between paroxetine and sertraline yielded mixed results. Therefore, the relative relationship of the stable pattern is robust across designs for fluoxetine but not for paroxetine and sertraline. Further, application of commonly applied selection criteria may make a sample less representative and reduce the measured rates of stable antidepressant use, potentially leading to underestimation of the benefits of pharmacotherapy. PMID:9737838

  1. The Structural Basis of Cryptosporidium-Specific IMP Dehydrogenase Inhibitor Selectivity

    SciTech Connect

    MacPherson, Iain S.; Kirubakaran, Sivapriya; Gorla, Suresh Kumar; Riera, Thomas V.; D’Aquino, J. Alejandro; Zhang, Minjia; Cuny, Gregory D.; Hedstrom, Lizbeth

    2010-03-29

    Cryptosporidium parvum is a potential biowarfare agent, an important AIDS pathogen, and a major cause of diarrhea and malnutrition. No vaccines or effective drug treatment exist to combat Cryptosporidium infection. This parasite relies on inosine 5{prime}-monophosphate dehydrogenase (IMPDH) to obtain guanine nucleotides, and inhibition of this enzyme blocks parasite proliferation. Here, we report the first crystal structures of CpIMPDH. These structures reveal the structural basis of inhibitor selectivity and suggest a strategy for further optimization. Using this information, we have synthesized low-nanomolar inhibitors that display 10{sup 3} selectivity for the parasite enzyme over human IMPDH2.

  2. First Selective CYP11B1 Inhibitors for the Treatment of Cortisol-Dependent Diseases

    PubMed Central

    2010-01-01

    Outgoing from an etomidate-based design concept, we succeeded in the development of a series of highly active and selective inhibitors of CYP11B1, the key enzyme of cortisol biosynthesis, as potential drugs for the treatment of Cushing's syndrome and related diseases. Thus, compound 33 (IC50 = 152 nM) is the first CYP11B1 inhibitor showing a rather good selectivity toward the most important steroidogenic CYP enzymes aldosterone synthase (CYP11B2), the androgen-forming CYP17, and aromatase (estrogen synthase, CYP19). PMID:24900247

  3. Design and synthesis of novel chalcones as potent selective monoamine oxidase-B inhibitors.

    PubMed

    Hammuda, Arwa; Shalaby, Raed; Rovida, Stefano; Edmondson, Dale E; Binda, Claudia; Khalil, Ashraf

    2016-05-23

    A novel series of substituted chalcones were designed and synthesized to be evaluated as selective human MAO-B inhibitors. A combination of either methylsulfonyl or trifluoromethyl substituents on the aromatic ketone moiety with a benzodioxol ring on the other end of the chalcone scaffold was investigated. The compounds were tested for their inhibitory activities on both human MAO-A and B. All compounds appeared to be selective MAO-B inhibitors with Ki values in the micromolar to submicromolar range. Molecular modeling studies have been performed to get insight into the binding mode of the synthesized compounds to human MAO-B active site. PMID:26974383

  4. Ethynylflavones, Highly Potent, and Selective Inhibitors of Cytochrome P450 1A1

    PubMed Central

    2015-01-01

    The flavone backbone is a well-known pharmacophore present in a number of substrates and inhibitors of various P450 enzymes. In order to find highly potent and novel P450 family I enzyme inhibitors, an acetylene group was incorporated into six different positions of flavone. The introduction of an acetylene group at certain locations of the flavone backbone lead to time-dependent inhibitors of P450 1A1. 3′-Ethynylflavone, 4′-ethynylflavone, 6-ethynylflavone, and 7-ethynylflavone (KI values of 0.035–0.056 μM) show strong time-dependent inhibition of P450 1A1, while 5-ethynylflavone (KI value of 0.51 μM) is a moderate time-dependent inhibitor of this enzyme. Meanwhile, 4′-ethynylflavone and 6-ethynylflavone are highly selective inhibitors toward this enzyme. Especially, 6-ethynylflavone possesses a Ki value of 0.035 μM for P450 1A1 177- and 15-fold lower than those for P450s 1A2 and 1B1, respectively. The docking postures observed in the computational simulations show that the orientation of the acetylene group determines its capability to react with P450s 1A1 and 1A2. Meanwhile, conformational analysis indicates that the shape of an inhibitor determines its inhibitory selectivity toward these enzymes. PMID:25033111

  5. Discovery of potent and selective sirtuin 2 (SIRT2) inhibitors using a fragment-based approach.

    PubMed

    Cui, Huaqing; Kamal, Zeeshan; Ai, Teng; Xu, Yanli; More, Swati S; Wilson, Daniel J; Chen, Liqiang

    2014-10-23

    Sirtuin 2 (SIRT2) is one of the sirtuins, a family of NAD(+)-dependent deacetylases that act on a variety of histone and non-histone substrates. Accumulating biological functions and potential therapeutic applications have drawn interest in the discovery and development of SIRT2 inhibitors. Herein we report our discovery of novel SIRT2 inhibitors using a fragment-based approach. Inspired by the purported close binding proximity of suramin and nicotinamide, we prepared two sets of fragments, namely, the naphthylamide sulfonic acids and the naphthalene-benzamides and -nicotinamides. Biochemical evaluation of these two series provided structure-activity relationship (SAR) information, which led to the design of (5-benzamidonaphthalen-1/2-yloxy)nicotinamide derivatives. Among these inhibitors, one compound exhibited high anti-SIRT2 activity (48 nM) and excellent selectivity for SIRT2 over SIRT1 and SIRT3. In vitro, it also increased the acetylation level of α-tubulin, a well-established SIRT2 substrate, in both concentration- and time-dependent manners. Further kinetic studies revealed that this compound behaves as a competitive inhibitor against the peptide substrate and most likely as a noncompetitive inhibitor against NAD(+). Taken together, these results indicate that we have discovered a potent and selective SIRT2 inhibitor whose novel structure merits further exploration. PMID:25275824

  6. Substrate-Guided Design of Selective FXIIa Inhibitors Based on the Plant-Derived Momordica cochinchinensis Trypsin Inhibitor-II (MCoTI-II) Scaffold.

    PubMed

    Swedberg, Joakim E; Mahatmanto, Tunjung; Abdul Ghani, Hafiza; de Veer, Simon J; Schroeder, Christina I; Harris, Jonathan M; Craik, David J

    2016-08-11

    Thrombosis is a leading cause of morbidity and mortality associated with cardiovascular diseases. Inhibition of factor XIIa (FXIIa) provides thrombus protection without bleeding complications. Here, we defined the extended substrate specificity of FXIIa and its close homologue factor Xa and used these data, together with inhibitor-based and structure-guided methods, to engineer selective FXIIa inhibitors based on Momordica cochinchinensis trypsin inhibitor-II. PMID:27434175

  7. Inhibitors

    MedlinePlus

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

  8. Field trials for corrosion inhibitor selection and optimization, using a new generation of electrical resistance probes

    SciTech Connect

    Ridd, B.; Blakset, T.J.; Queen, D.

    1998-12-31

    Even with today`s availability of corrosion resistant alloys, carbon steels protected by corrosion inhibitors still dominate the material selection for pipework in the oil and gas production. Even though laboratory screening tests of corrosion inhibitor performance provides valuable data, the real performance of the chemical can only be studied through field trials which provide the ultimate test to evaluate the effectiveness of an inhibitor under actual operating conditions. A new generation of electrical resistance probe has been developed, allowing highly sensitive and immediate response to changes in corrosion rates on the internal environment of production pipework. Because of the high sensitivity, the probe responds to small changes in the corrosion rate, and it provides the corrosion engineer with a highly effective method of optimizing the use of inhibitor chemicals resulting in confidence in corrosion control and minimizing detrimental environmental effects.

  9. Design of potent and selective human cathepsin K inhibitors that span the active site

    PubMed Central

    Thompson, Scott K.; Halbert, Stacie M.; Bossard, Mary J.; Tomaszek, Thaddeus A.; Levy, Mark A.; Zhao, Baoguang; Smith, Ward W.; Abdel-Meguid, Sherin S.; Janson, Cheryl A.; D’Alessio, Karla J.; McQueney, Michael S.; Amegadzie, Bernard Y.; Hanning, Charles R.; DesJarlais, Renee L.; Briand, Jacques; Sarkar, Susanta K.; Huddleston, Michael J.; Ijames, Carl F.; Carr, Steven A.; Garnes, Keith T.; Shu, Art; Heys, J. Richard; Bradbeer, Jeremy; Zembryki, Denise; Lee-Rykaczewski, Liz; James, Ian E.; Lark, Michael W.; Drake, Fred H.; Gowen, Maxine; Gleason, John G.; Veber, Daniel F.

    1997-01-01

    Potent and selective active-site-spanning inhibitors have been designed for cathepsin K, a cysteine protease unique to osteoclasts. They act by mechanisms that involve tight binding intermediates, potentially on a hydrolytic pathway. X-ray crystallographic, MS, NMR spectroscopic, and kinetic studies of the mechanisms of inhibition indicate that different intermediates or transition states are being represented that are dependent on the conditions of measurement and the specific groups flanking the carbonyl in the inhibitor. The species observed crystallographically are most consistent with tetrahedral intermediates that may be close approximations of those that occur during substrate hydrolysis. Initial kinetic studies suggest the possibility of irreversible and reversible active-site modification. Representative inhibitors have demonstrated antiresorptive activity both in vitro and in vivo and therefore are promising leads for therapeutic agents for the treatment of osteoporosis. Expansion of these inhibitor concepts can be envisioned for the many other cysteine proteases implicated for therapeutic intervention. PMID:9405598

  10. Computational selection of inhibitors of Abeta aggregation and neuronal toxicity.

    PubMed

    Chen, Deliang; Martin, Zane S; Soto, Claudio; Schein, Catherine H

    2009-07-15

    Alzheimer's disease (AD) is characterized by the cerebral accumulation of misfolded and aggregated amyloid-beta protein (Abeta). Disease symptoms can be alleviated, in vitro and in vivo, by 'beta-sheet breaker' pentapeptides that reduce plaque load. However the peptide nature of these compounds, made them biologically unstable and unable to penetrate membranes with high efficiency. The main goal of this study was to use computational methods to identify small molecule mimetics with better drug-like properties. For this purpose, the docked conformations of the active peptides were used to identify compounds with similar activities. A series of related beta-sheet breaker peptides were docked to solid state NMR structures of a fibrillar form of Abeta. The lowest energy conformations of the active peptides were used to design three dimensional (3D)-pharmacophores, suitable for screening the NCI database with Unity. Small molecular weight compounds with physicochemical features and a conformation similar to the active peptides were selected, ranked by docking and biochemical parameters. Of 16 diverse compounds selected for experimental screening, 2 prevented and reversed Abeta aggregation at 2-3microM concentration, as measured by Thioflavin T (ThT) fluorescence and ELISA assays. They also prevented the toxic effects of aggregated Abeta on neuroblastoma cells. Their low molecular weight and aqueous solubility makes them promising lead compounds for treating AD. PMID:19540126

  11. Crystal Structure of Checkpoint Kinase 2 in Complex with Nsc 109555, a Potent and Selective Inhibitor

    SciTech Connect

    Lountos, George T.; Tropea, Joseph E.; Zhang, Di; Jobson, Andrew G.; Pommier, Yves; Shoemaker, Robert H.; Waugh, David S.

    2009-03-05

    Checkpoint kinase 2 (Chk2), a ser/thr kinase involved in the ATM-Chk2 checkpoint pathway, is activated by genomic instability and DNA damage and results in either arrest of the cell cycle to allow DNA repair to occur or apoptosis if the DNA damage is severe. Drugs that specifically target Chk2 could be beneficial when administered in combination with current DNA-damaging agents used in cancer therapy. Recently, a novel inhibitor of Chk2, NSC 109555, was identified that exhibited high potency (IC{sub 50} = 240 nM) and selectivity. This compound represents a new chemotype and lead for the development of novel Chk2 inhibitors that could be used as therapeutic agents for the treatment of cancer. To facilitate the discovery of new analogs of NSC 109555 with even greater potency and selectivity, we have solved the crystal structure of this inhibitor in complex with the catalytic domain of Chk2. The structure confirms that the compound is an ATP-competitive inhibitor, as the electron density clearly reveals that it occupies the ATP-binding pocket. However, the mode of inhibition differs from that of the previously studied structure of Chk2 in complex with debromohymenialdisine, a compound that inhibits both Chk1 and Chk2. A unique hydrophobic pocket in Chk2, located very close to the bound inhibitor, presents an opportunity for the rational design of compounds with higher binding affinity and greater selectivity.

  12. Potent, Highly Selective, and Orally Bioavailable Gem-Difluorinated Monocationic Inhibitors of Neuronal Nitric Oxide Synthase

    PubMed Central

    Xue, Fengtian; Li, Huiying; Delker, Silvia L.; Fang, Jianguo; Martásek, Pavel; Roman, Linda J.; Poulos, Thomas L.; Silverman, Richard B.

    2010-01-01

    In our efforts to discover neuronal isoform selective nitric oxide synthase (NOS) inhibitors we have developed a series of compounds containing a pyrrolidine ring with two stereogenic centers. The enantiomerically pure compounds, (S,S) vs. (R,R), exhibited two different binding orientations, with (R,R) inhibitors showing much better potency and selectivity. To improve the bioavailability of these inhibitors we have introduced a CF2 moiety geminal to an amino group in the long tail of one of these inhibitors, which reduced its basicity, resulting in compounds with monocationic character under physiological pH conditions. Biological evaluations have led to a nNOS inhibitor with a Ki of 36 nM and high selectivity for nNOS over eNOS (3800-fold) and iNOS (1400-fold). MM-PBSA calculations indicated that the low pKa NH is, at least, partially protonated when bound to the active site. A comparison of rat oral bioavailability of the difluorinated compound to the parent molecule shows 22% for the difluorinated compound versus essentially no oral bioavailability for the parent compound. This indicates that the goal of this research to make compounds with only one protonated nitrogen atom at physiological pH to allow for membrane permeability, but which can become protonated when bound to NOS, has been accomplished. PMID:20843082

  13. Synthesis of 2,6-disubstituted benzylamine derivatives as reversible selective inhibitors of copper amine oxidases.

    PubMed

    Lucchesini, Francesco; Pocci, Marco; Alfei, Silvana; Bertini, Vincenzo; Buffoni, Franca

    2014-03-01

    In order to obtain substrate-like inhibitors of copper amine oxidases (CAOs), a class of enzymes involved in important cellular processes as well as in crosslinking of elastin and collagen and removal of biogenic primary amines, we synthesized a set of benzylamine derivatives properly substituted at positions 2 and 6 and studied their biological activity towards some members of CAOs. With benzylamines 6, 7, 8 containing linear alkoxy groups we obtained reversible inhibitors of benzylamine oxidase (BAO), very active and selective toward diamine oxidase (DAO), lysyl oxidase (LO) and monoamine oxidase B (MAO B) characterized by a certain toxicity consequent to the crossing of the brain barrier. Poorly toxic, up to very active, reversible inhibitors of BAO, very selective toward DAO, LO and MAO B, were obtained with benzylamines 10, 11, 12 containing hydrophilic ω-hydroxyalkoxy groups. With benzylamines 13, 14, 15, containing linear alkyl groups endowed with steric, but not conjugative effects for the absence of properly positioned oxygen atoms, we synthesized moderately active inhibitors of BAO reversible and selective toward DAO, LO and MAO B. The cross examination of the entire biological data brought us to the conclusion that the bioactive synthesized compounds most likely exert their physiological role of reversible inhibitors in consequence of the formation of a plurality of hydrogen bonds or hydrophobic non-covalent interactions with proper sites in the protein. Accordingly, the reported inhibitors may be considered as a set of research tools for general biological studies and the formation of enzyme complexes useful for X-ray structure determinations aimed at the design of more sophisticated inhibitors to always better modulate the protein activity without important side effects. PMID:24529308

  14. GSK114: A selective inhibitor for elucidating the biological role of TNNI3K.

    PubMed

    Lawhorn, Brian G; Philp, Joanne; Graves, Alan P; Shewchuk, Lisa; Holt, Dennis A; Gatto, Gregory J; Kallander, Lara S

    2016-07-15

    A series of selective TNNI3K inhibitors were developed by modifying the hinge-binding heterocycle of a previously reported dual TNNI3K/B-Raf inhibitor. The resulting quinazoline-containing compounds exhibit a large preference (up to 250-fold) for binding to TNNI3K versus B-Raf, are useful probes for elucidating the biological pathways associated with TNNI3K, and are leads for discovering novel cardiac medicines. GSK114 emerged as a leading inhibitor, displaying significant bias (40-fold) for TNNI3K over B-Raf, exceptional broad spectrum kinase selectivity, and adequate oral exposure to enable its use in cellular and in vivo studies. PMID:27246618

  15. Sugar-Based Arylsulfonamide Carboxylates as Selective and Water-Soluble Matrix Metalloproteinase-12 Inhibitors.

    PubMed

    Nuti, Elisa; Cuffaro, Doretta; D'Andrea, Felicia; Rosalia, Lea; Tepshi, Livia; Fabbi, Marina; Carbotti, Grazia; Ferrini, Silvano; Santamaria, Salvatore; Camodeca, Caterina; Ciccone, Lidia; Orlandini, Elisabetta; Nencetti, Susanna; Stura, Enrico A; Dive, Vincent; Rossello, Armando

    2016-08-01

    Matrix metalloproteinase-12 (MMP-12) can be considered an attractive target to study selective inhibitors useful in the development of new therapies for lung and cardiovascular diseases. In this study, a new series of arylsulfonamide carboxylates, with increased hydrophilicity resulting from conjugation with a β-N-acetyl-d-glucosamine moiety, were designed and synthesized as MMP-12 selective inhibitors. Their inhibitory activity was evaluated on human MMPs by using the fluorimetric assay, and a crystallographic analysis was performed to characterize their binding mode. Among these glycoconjugates, a nanomolar MMP-12 inhibitor with improved water solubility, compound 3 [(R)-2-(N-(2-(3-(2-acetamido-2-deoxy-β-d-glucopyranosyl)thioureido)ethyl)biphenyl-4-ylsulfonamido)-3-methylbutanoic acid], was identified. PMID:27356908

  16. Structure-activity relationships of the cycloalkanol ethylamine scaffold: discovery of selective norepinephrine reuptake inhibitors.

    PubMed

    Mahaney, Paige E; Gavrin, Lori K; Trybulski, Eugene J; Stack, Gary P; Vu, T An; Cohn, Stephen T; Ye, Fei; Belardi, Justin K; Santilli, Arthur A; Sabatucci, Joseph P; Leiter, Jennifer; Johnston, Grace H; Bray, Jenifer A; Burroughs, Kevin D; Cosmi, Scott A; Leventhal, Liza; Koury, Elizabeth J; Zhang, Yingru; Mugford, Cheryl A; Ho, Douglas M; Rosenzweig-Lipson, Sharon J; Platt, Brian; Smith, Valerie A; Deecher, Darlene C

    2008-07-10

    Further exploration of the cycloalkanol ethylamine scaffold, of which venlafaxine ( 1) is a member, was undertaken to develop novel and selective norepinephrine reuptake inhibitors (NRIs) for evaluation in a variety of predictive animal models. These efforts led to the discovery of a piperazine-containing analogue, 17g (WY-46824), that exhibited potent norepinephrine reuptake inhibition, excellent selectivity over the serotonin transporter, but no selectivity over the dopamine transporter. Synthesis and testing of a series of cyclohexanol ethylpiperazines identified ( S)-(-)- 17i (WAY-256805), a potent norepinephrine reuptake inhibitor (IC 50 = 82 nM, K i = 50 nM) that exhibited excellent selectivity over both the serotonin and dopamine transporters and was efficacious in animal models of depression, pain, and thermoregulatory dysfunction. PMID:18557608

  17. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides.

    PubMed

    Nguyen, G T T; Erlenkamp, G; Jäck, O; Küberl, A; Bott, M; Fiorani, F; Gohlke, H; Groth, G

    2016-01-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world's most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2',3',4',3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2',3',4'-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15-45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

  18. Discovery of a Potent and Selective ROMK Inhibitor with Pharmacokinetic Properties Suitable for Preclinical Evaluation

    PubMed Central

    2015-01-01

    A new subseries of ROMK inhibitors exemplified by 28 has been developed from the initial screening hit 1. The excellent selectivity for ROMK inhibition over related ion channels and pharmacokinetic properties across preclinical species support further preclinical evaluation of 28 as a new mechanism diuretic. Robust pharmacodynamic effects in both SD rats and dogs have been demonstrated. PMID:26191360

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

    PubMed

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

    2016-01-14

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

  20. In Utero Exposure to Selective Serotonin Reuptake Inhibitors and Risk for Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Gidaya, Nicole B.; Lee, Brian K.; Burstyn, Igor; Yudell, Michael; Mortensen, Erik L.; Newschaffer, Craig J.

    2014-01-01

    We investigated whether there is an association between increased risk for autism spectrum disorders (ASD) and selective serotonin reuptake inhibitors (SSRIs) used during pregnancy. This study used Denmark's health and population registers to obtain information regarding prescription drugs, ASD diagnosis, and health and socioeconomic status.…

  1. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

    PubMed Central

    Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

    2016-01-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2′,3′,4′,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2′,3′,4′-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

  2. Discovery of potent, selective, and orally bioavailable inhibitors of interleukin-1 receptor-associate kinase-4.

    PubMed

    Wang, Zhulun; Sun, Daqing; Johnstone, Sheree; Cao, Zhaodan; Gao, Xiong; Jaen, Juan C; Liu, Jingqian; Lively, Sarah; Miao, Shichang; Sudom, Athena; Tomooka, Craig; Walker, Nigel P C; Wright, Matthew; Yan, Xuelei; Ye, Qiuping; Powers, Jay P

    2015-12-01

    In this Letter, we report the continued optimization of the N-acyl-2-aminobenzimidazole series, focusing in particular on the N-alkyl substituent and 5-position of the benzimidazole based on the binding mode and the early SAR. These efforts led to the discovery of 16, a highly potent, selective, and orally bioavailable inhibitor of IRAK-4. PMID:26526214

  3. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

    NASA Astrophysics Data System (ADS)

    Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

    2016-06-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2‧,3‧,4‧,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2‧,3‧,4‧-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme.

  4. 1,3-Dimethyl Benzimidazolones Are Potent, Selective Inhibitors of the BRPF1 Bromodomain

    PubMed Central

    2014-01-01

    The BRPF (bromodomain and PHD finger-containing) protein family are important scaffolding proteins for assembly of MYST histone acetyltransferase complexes. Here, we report the discovery, binding mode, and structure–activity relationship (SAR) of the first potent, selective series of inhibitors of the BRPF1 bromodomain. PMID:25408830

  5. Discovery of CX-6258. A Potent, Selective, and Orally Efficacious pan-Pim Kinases Inhibitor.

    PubMed

    Haddach, Mustapha; Michaux, Jerome; Schwaebe, Michael K; Pierre, Fabrice; O'Brien, Sean E; Borsan, Cosmin; Tran, Joe; Raffaele, Nicholas; Ravula, Suchitra; Drygin, Denis; Siddiqui-Jain, Adam; Darjania, Levan; Stansfield, Ryan; Proffitt, Chris; Macalino, Diwata; Streiner, Nicole; Bliesath, Joshua; Omori, May; Whitten, Jeffrey P; Anderes, Kenna; Rice, William G; Ryckman, David M

    2012-02-01

    Structure-activity relationship analysis in a series of 3-(5-((2-oxoindolin-3-ylidene)methyl)furan-2-yl)amides identified compound 13, a pan-Pim kinases inhibitor with excellent biochemical potency and kinase selectivity. Compound 13 exhibited in vitro synergy with chemotherapeutics and robust in vivo efficacy in two Pim kinases driven tumor models. PMID:24900437

  6. Anhedonia Predicts Poorer Recovery among Youth with Selective Serotonin Reuptake Inhibitor Treatment-Resistant Depression

    ERIC Educational Resources Information Center

    McMakin, Dana L.; Olino, Thomas M.; Porta, Giovanna; Dietz, Laura J.; Emslie, Graham; Clarke, Gregory; Wagner, Karen Dineen; Asarnow, Joan R.; Ryan, Neal D.; Birmaher, Boris; Shamseddeen, Wael; Mayes, Taryn; Kennard, Betsy; Spirito, Anthony; Keller, Martin; Lynch, Frances L.; Dickerson, John F.; Brent, David A.

    2012-01-01

    Objective: To identify symptom dimensions of depression that predict recovery among selective serotonin reuptake inhibitor (SSRI) treatment-resistant adolescents undergoing second-step treatment. Method: The Treatment of Resistant Depression in Adolescents (TORDIA) trial included 334 SSRI treatment-resistant youth randomized to a medication…

  7. Structure-Guided Evolution of Potent and Selective CHK1 Inhibitors through Scaffold Morphing

    PubMed Central

    2011-01-01

    Pyrazolopyridine inhibitors with low micromolar potency for CHK1 and good selectivity against CHK2 were previously identified by fragment-based screening. The optimization of the pyrazolopyridines to a series of potent and CHK1-selective isoquinolines demonstrates how fragment-growing and scaffold morphing strategies arising from a structure-based understanding of CHK1 inhibitor binding can be combined to successfully progress fragment-derived hit matter to compounds with activity in vivo. The challenges of improving CHK1 potency and selectivity, addressing synthetic tractability, and achieving novelty in the crowded kinase inhibitor chemical space were tackled by multiple scaffold morphing steps, which progressed through tricyclic pyrimido[2,3-b]azaindoles to N-(pyrazin-2-yl)pyrimidin-4-amines and ultimately to imidazo[4,5-c]pyridines and isoquinolines. A potent and highly selective isoquinoline CHK1 inhibitor (SAR-020106) was identified, which potentiated the efficacies of irinotecan and gemcitabine in SW620 human colon carcinoma xenografts in nude mice. PMID:22111927

  8. 1,2-disubstituted cyclohexane derived tripeptide aldehydes as novel selective thrombin inhibitors.

    PubMed

    Harmat, N J; Di Bugno, C; Criscuoli, M; Giorgi, R; Lippi, A; Martinelli, A; Monti, S; Subissi, A

    1998-05-19

    A series of tripeptide arginine aldehydes was synthesized by replacement of proline with 1,2-disubstituted cyclohexane derivatives in the sequence of D-MePhe-Pro-Arg-H. Based on molecular modeling, further modification of the D-MePhe residue resulted in a potent and selective thrombin inhibitor. PMID:9871744

  9. Selective Monocationic Inhibitors of Neuronal Nitric Oxide Synthase. Binding Mode Insights from Molecular Dynamics Simulations

    PubMed Central

    Huang, He; Ji, Haitao; Li, Huiying; Jing, Qing; Labby, Kristin Jansen; Martásek, Pavel; Roman, Linda J.; Poulos, Thomas L.; Silverman, Richard B.

    2012-01-01

    The reduction of pathophysiologic levels of nitric oxide through inhibition of neuronal nitric oxide synthase (nNOS) has the potential to be therapeutically beneficial in various neurodegenerative diseases. We have developed a series of pyrrolidine-based nNOS inhibitors that exhibit excellent potencies and isoform selectivities (J. Am. Chem. Soc. 2010, 132, 5437). However, there are still important challenges, such as how to decrease the multiple positive charges derived from basic amino groups, which contribute to poor bioavailability, without losing potency and/or selectivity. Here we present an interdisciplinary study combining molecular docking, crystallography, molecular dynamics simulations, synthesis, and enzymology to explore potential pharmacophoric features of nNOS inhibitors and to design potent and selective monocationic nNOS inhibitors. The simulation results indicate that different hydrogen bond patterns, electrostatic interactions, hydrophobic interactions, and a water molecule bridge are key factors for stabilizing ligands and controlling ligand orientation. We find that a heteroatom in the aromatic head or linker chain of the ligand provides additional stability and blocks the substrate binding pocket. Finally, the computational insights are experimentally validated with double-headed pyridine analogs. The compounds reported here are among the most potent and selective monocationic pyrrolidine-based nNOS inhibitors reported to date, and 10 shows improved membrane permeability. PMID:22731813

  10. Selective Serotonin Reuptake Inhibitor-Induced Sexual Dysfunction in Adolescents: A Review.

    ERIC Educational Resources Information Center

    Scharko, Alexander M.

    2004-01-01

    Objective: To review the existing literature on selective serotonin reuptake inhibitor (SSRI)-induced sexual dysfunction in adolescents. Method: A literature review of SSRI-induced adverse effects in adolescents focusing on sexual dysfunction was done. Nonsexual SSRI-induced adverse effects were compared in adult and pediatric populations.…

  11. Discovery of WAY-260022, a Potent and Selective Inhibitor of the Norepinephrine Transporter.

    PubMed

    Gavrin, Lori K; Mahaney, Paige E; Jenkins, Douglas; Nogle, Lisa M; Mugford, Cheryl A; Huselton, Christine; Leiter, Jennifer; Johnston, Grace H; Bray, Jenifer A; Burroughs, Kevin D; Cosmi, Scott A; Alfinito, Peter; Ho, Douglas M; Deecher, Darlene C; Trybulski, Eugene J

    2010-06-10

    The potency and selectivity of a series of 1-{(1S)-2-[amino]-1-[3-(trifluoromethoxy)phenyl]ethyl}cyclohexanol analogues are described. These compounds were prepared to improve in vitro metabolic stability and achieve brain penetration. Compound 13 (WAY-260022, NRI-022) was found to be a potent inhibitor of norepinephrine reuptake and demonstrated excellent selectivity over the serotonin and dopamine transporters. Additionally, 13 exhibited oral efficacy in a rat model of thermoregulatory dysfunction. PMID:24900182

  12. Discovery of WAY-260022, a Potent and Selective Inhibitor of the Norepinephrine Transporter

    PubMed Central

    2010-01-01

    The potency and selectivity of a series of 1-{(1S)-2-[amino]-1-[3-(trifluoromethoxy)phenyl]ethyl}cyclohexanol analogues are described. These compounds were prepared to improve in vitro metabolic stability and achieve brain penetration. Compound 13 (WAY-260022, NRI-022) was found to be a potent inhibitor of norepinephrine reuptake and demonstrated excellent selectivity over the serotonin and dopamine transporters. Additionally, 13 exhibited oral efficacy in a rat model of thermoregulatory dysfunction. PMID:24900182

  13. A Novel Selective Prostaglandin E2 Synthesis Inhibitor Relieves Pyrexia and Chronic Inflammation in Rats.

    PubMed

    Sugita, Ryusuke; Kuwabara, Harumi; Sugimoto, Kotaro; Kubota, Kazufumi; Imamura, Yuichiro; Kiho, Toshihiro; Tengeiji, Atsushi; Kawakami, Katsuhiro; Shimada, Kohei

    2016-04-01

    Prostaglandin E2 (PGE2) is a terminal prostaglandin in the cyclooxygenase (COX) pathway. Inhibition of PGE2 production may relieve inflammatory symptoms such as fever, arthritis, and inflammatory pain. We report here the profile of a novel selective PGE2 synthesis inhibitor, compound A [N-[(1S,3S)-3-carbamoylcyclohexyl]-1-(6-methyl-3-phenylquinolin-2-yl)piperidine-4-carboxamide], in animal models of pyrexia and inflammation. The compound selectively suppressed the synthesis of PGE2 in human alveolar adenocarcinoma cell line A549 cells and rat macrophages. In the lipopolysaccharide-induced pyrexia model, this compound selectively reduced PGE2 production in cerebrospinal fluid and showed an anti-pyretic effect. In the adjuvant-induced arthritis model, compound A therapeutically decreased foot swelling in the established arthritis. Our data demonstrates that selective suppression of PGE2 synthesis shows anti-pyretic and anti-inflammatory effects, suggesting that selective PGE2 synthesis inhibitors can be applied as an alternative treatment to nonsteroidal, anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors. PMID:26923147

  14. Discovery and characterization of novel selective inhibitors of carbonic anhydrase IX.

    PubMed

    Dudutienė, Virginija; Matulienė, Jurgita; Smirnov, Alexey; Timm, David D; Zubrienė, Asta; Baranauskienė, Lina; Morkūnaite, Vaida; Smirnovienė, Joana; Michailovienė, Vilma; Juozapaitienė, Vaida; Mickevičiūtė, Aurelija; Kazokaitė, Justina; Bakšytė, Sandra; Kasiliauskaitė, Aistė; Jachno, Jelena; Revuckienė, Jurgita; Kišonaitė, Miglė; Pilipuitytė, Vilma; Ivanauskaitė, Eglė; Milinavičiūtė, Goda; Smirnovas, Vytautas; Petrikaitė, Vilma; Kairys, Visvaldas; Petrauskas, Vytautas; Norvaišas, Povilas; Lingė, Darius; Gibieža, Paulius; Capkauskaitė, Edita; Zakšauskas, Audrius; Kazlauskas, Egidijus; Manakova, Elena; Gražulis, Saulius; Ladbury, John E; Matulis, Daumantas

    2014-11-26

    Human carbonic anhydrase IX (CA IX) is highly expressed in tumor tissues, and its selective inhibition provides a potential target for the treatment of numerous cancers. Development of potent, highly selective inhibitors against this target remains an unmet need in anticancer therapeutics. A series of fluorinated benzenesulfonamides with substituents on the benzene ring was designed and synthesized. Several of these exhibited a highly potent and selective inhibition profile against CA IX. Three fluorine atoms significantly increased the affinity by withdrawing electrons and lowering the pKa of the benzenesulfonamide group. The bulky ortho substituents, such as cyclooctyl or even cyclododecyl groups, fit into the hydrophobic pocket in the active site of CA IX but not CA II, as shown by the compound's co-crystal structure with chimeric CA IX. The strongest inhibitor of recombinant human CA IX's catalytic domain in human cells achieved an affinity of 50 pM. However, the high affinity diminished the selectivity. The most selective compound for CA IX exhibited 10 nM affinity. The compound that showed the best balance between affinity and selectivity bound with 1 nM affinity. The inhibitors described in this work provide the basis for novel anticancer therapeutics targeting CA IX. PMID:25358084

  15. Pyridopyrimidinone Derivatives as Potent and Selective c-Jun N-Terminal Kinase (JNK) Inhibitors

    PubMed Central

    2015-01-01

    A novel series of 2-aminopyridopyrimidinone based JNK (c-jun N-terminal kinase) inhibitors were discovered and developed. Structure–activity relationships (SARs) were systematically developed utilizing biochemical and cell based assays and in vitro and in vivo drug metabolism and pharmacokinetic (DMPK) studies. Through the optimization of lead compound 1, several potent and selective JNK inhibitors with high oral bioavailability were developed. Inhibitor 13 was a potent JNK3 inhibitor (IC50 = 15 nM), had high selectivity against p38 (IC50 > 10 μM), had high potency in functional cell based assays, and had high stability in human liver microsome (t1/2 = 76 min), a clean CYP-450 inhibition profile, and excellent oral bioavailability (%F = 87). Moreover, cocrystal structures of compounds 13 and 22 in JNK3 were solved at 2.0 Å. These structures elucidated the binding mode (Type-I binding) and can pave the way for further inhibitor design of this pyridopyrimidinone scaffold for JNK inhibition. PMID:25893042

  16. A roadmap to evaluate the proteome-wide selectivity of covalent kinase inhibitors

    PubMed Central

    Dix, Melissa M.; Douhan, John; Gilbert, Adam M.; Hett, Erik C.; Johnson, Theodore O.; Joslyn, Chris; Kath, John C.; Niessen, Sherry; Roberts, Lee R.; Schnute, Mark E.; Wang, Chu; Hulce, Jonathan J.; Wei, Baoxian; Whiteley, Laurence O.; Hayward, Matthew M.; Cravatt, Benjamin F.

    2014-01-01

    Kinases are principal components of signal transduction pathways and the focus of intense basic and drug discovery research. Irreversible inhibitors that covalently modify non-catalytic cysteines in kinase active-sites have emerged as valuable probes and approved drugs. Many protein classes, however, possess functional cysteines and therefore understanding the proteome-wide selectivity of covalent kinase inhibitors is imperative. Here, we accomplish this objective using activity-based protein profiling coupled with quantitative mass spectrometry to globally map the targets, both specific and non-specific, of covalent kinase inhibitors in human cells. Many of the specific off-targets represent non-kinase proteins that, interestingly, possess conserved, active-site cysteines. We define windows of selectivity for covalent kinase inhibitors and show that, when these windows are exceeded, rampant proteome-wide reactivity and kinase target-independent cell death conjointly occur. Our findings, taken together, provide an experimental roadmap to illuminate opportunities and surmount challenges for the development of covalent kinase inhibitors. PMID:25038787

  17. A SMALL MOLECULE SCREEN IDENTIFIES SELECTIVE INHIBITORS OF UREA TRANSPORTER UT-A

    PubMed Central

    Esteva-Font, Cristina; Phuan, Puay-Wah; Anderson, Marc O.; Verkman, A.S.

    2013-01-01

    SUMMARY Urea transporter (UT) proteins, including UT-A in kidney tubule epithelia and UT-B in vasa recta microvessels, facilitate urinary concentrating function. A screen for UT-A inhibitors was developed in MDCK cells expressing UT-A1, water channel aquaporin-1, and YFP-H148Q/V163S. An inwardly directed urea gradient produces cell shrinking followed by UT-A1-dependent swelling, which was monitored by YFP-H148Q/V163S fluorescence. Screening of ~90,000 synthetic small molecules yielded four classes of UT-A1 inhibitors with low micromolar IC50 that fully and reversibly inhibited urea transport by a non-competitive mechanism. Structure-activity analysis of >400 analogs revealed UT-A1-selective and UT-A1/UT-B non-selective inhibitors. Docking computations based on homology models of UT-A1 suggested inhibitor binding sites. UT-A inhibitors may be useful as diuretics (‘urearetics’) with a novel mechanism of action that may be effective in fluid-retaining conditions in which conventional salt transport-blocking diuretics have limited efficacy. PMID:24055006

  18. Use of Selective Cyclooxygenase-2 Inhibitors, Other Analgesics, and Risk of Glioma

    PubMed Central

    Seliger, Corinna; Meier, Christoph R.; Becker, Claudia; Jick, Susan S.; Bogdahn, Ulrich; Hau, Peter; Leitzmann, Michael F.

    2016-01-01

    Background Selective cyclooxygenase-2 (COX-2) inhibitors are analgesic, antipyretic, and anti-inflammatory drugs. They have been found to inhibit the development of glioma in laboratory investigations. Whether these drugs reduce the risk of glioma incidence in humans is unknown. Methods We conducted a matched case-control analysis using the U.K.-based Clinical Practice Research Datalink (CPRD). We identified 2,469 cases matched to 24,690 controls on age, sex, calendar time, general practice, and number of years of active history in the CPRD prior to the index date. We conducted conditional logistic regression analyses to determine relative risks, estimated as odds ratios (ORs) with 95% confidence intervals (CIs) of glioma in relation to use of selective COX-2 inhibitors, adjusted for several confounding variables. Results Use of selective COX-2 inhibitors was unrelated to risk of glioma (adjusted OR for 1–9 versus 0 prescriptions = 1.02; 95% CI = 0.92–1.13, 10–29 versus 0 prescriptions = 1.01; 95% CI = 0.80–1.28, ≥30 versus 0 prescriptions = 1.16; 95% CI = 0.86–1.55). Trends for increasing numbers of prescriptions for other non-steroidal anti-inflammatory drugs (NSAIDs), and non-NSAID analgesics were also not associated with glioma risk. Conclusion Further epidemiologic studies are needed to confirm the null relation of use of selective COX-2 inhibitors to glioma risk and to explain the discrepancy between laboratory investigations and our observational study. Impact: Use of selective COX-2 inhibitors is unrelated to glioma risk. PMID:26871579

  19. A highly selective, reversible inhibitor identified by comparative chemoproteomics modulates diacylglycerol lipase activity in neurons

    PubMed Central

    Baggelaar, Marc P.; Chameau, Pascal J. P.; Kantae, Vasudev; Hummel, Jessica; Hsu, Ku-Lung; Janssen, Freek; van der Wel, Tom; Soethoudt, Marjolein; Deng, Hui; den Dulk, Hans; Allarà, Marco; Florea, Bogdan I.; Di Marzo, Vincenzo; Wadman, Wytse J.; Kruse, Chris G.; Overkleeft, Herman S.; Hankemeier, Thomas; Werkman, Taco R.; Cravatt, Benjamin F.; van der Stelt, Mario

    2016-01-01

    Diacylglycerol lipase (DAGL)-α and -β are enzymes responsible for the biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). Selective and reversible inhibitors are required to study the function of DAGLs in neuronal cells in an acute and temporal fashion, but they are currently lacking. Here, we describe the identification of a highly selective DAGL inhibitor using structure-guided and a chemoproteomics strategy to characterize the selectivity of the inhibitor in complex proteomes. Key to the success of this approach is the use of comparative and competitive activity-based proteome profiling (ABPP), in which broad-spectrum and tailor-made activity-based probes are combined to report on the inhibition of a protein family in its native environment. Competitive ABPP with broad-spectrum fluorophosphonate-based probes and specific β-lactone-based probes led to the discovery of α-ketoheterocycle LEI105 as a potent, highly selective and reversible dual DAGL-α/DAGL-β inhibitor. LEI105 did not affect other enzymes involved in endocannabinoid metabolism including abhydrolase domain-containing protein 6, abhydrolase domain-containing protein 12, monoacylglycerol lipase and fatty acid amide hydrolase and did not display affinity for the cannabinoid CB1 receptor. Targeted lipidomics revealed that LEI105 concentration-dependently reduced 2-AG levels, but not anandamide levels, in Neuro2A cells. We show that cannabinoid CB1-receptor-mediated short-term synaptic plasticity in a mouse hippocampal slice model can be reduced by LEI105. Thus, we have developed a highly selective DAGL inhibitor and provide new pharmacological evidence to support the hypothesis that ‘on demand biosynthesis’ of 2-AG is responsible for retrograde signaling. PMID:26083464

  20. Development of a potent and selective FLT3 kinase inhibitor by systematic expansion of a non-selective fragment-screening hit.

    PubMed

    Nakano, Hirofumi; Hasegawa, Tsukasa; Imamura, Riyo; Saito, Nae; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo

    2016-05-01

    A non-selective inhibitor (1) of FMS-like tyrosine kinase-3 (FLT3) was identified by fragment screening and systematically modified to afford a potent and selective inhibitor 26. We confirmed that 26 inhibited the growth of FLT-3-activated human acute myeloid leukemia cell line MV4-11. Our design strategy enabled rapid development of a novel type of FLT3 inhibitor from the hit fragment in the absence of target-structural information. PMID:26995531

  1. Structure- and function-based design of Plasmodium-selective proteasome inhibitors.

    PubMed

    Li, Hao; O'Donoghue, Anthony J; van der Linden, Wouter A; Xie, Stanley C; Yoo, Euna; Foe, Ian T; Tilley, Leann; Craik, Charles S; da Fonseca, Paula C A; Bogyo, Matthew

    2016-02-11

    The proteasome is a multi-component protease complex responsible for regulating key processes such as the cell cycle and antigen presentation. Compounds that target the proteasome are potentially valuable tools for the treatment of pathogens that depend on proteasome function for survival and replication. In particular, proteasome inhibitors have been shown to be toxic for the malaria parasite Plasmodium falciparum at all stages of its life cycle. Most compounds that have been tested against the parasite also inhibit the mammalian proteasome, resulting in toxicity that precludes their use as therapeutic agents. Therefore, better definition of the substrate specificity and structural properties of the Plasmodium proteasome could enable the development of compounds with sufficient selectivity to allow their use as anti-malarial agents. To accomplish this goal, here we use a substrate profiling method to uncover differences in the specificities of the human and P. falciparum proteasome. We design inhibitors based on amino-acid preferences specific to the parasite proteasome, and find that they preferentially inhibit the β2-subunit. We determine the structure of the P. falciparum 20S proteasome bound to the inhibitor using cryo-electron microscopy and single-particle analysis, to a resolution of 3.6 Å. These data reveal the unusually open P. falciparum β2 active site and provide valuable information about active-site architecture that can be used to further refine inhibitor design. Furthermore, consistent with the recent finding that the proteasome is important for stress pathways associated with resistance of artemisinin family anti-malarials, we observe growth inhibition synergism with low doses of this β2-selective inhibitor in artemisinin-sensitive and -resistant parasites. Finally, we demonstrate that a parasite-selective inhibitor could be used to attenuate parasite growth in vivo without appreciable toxicity to the host. Thus, the Plasmodium proteasome is a

  2. Quinalizarin as a potent, selective and cell-permeable inhibitor of protein kinase CK2.

    PubMed

    Cozza, Giorgio; Mazzorana, Marco; Papinutto, Elena; Bain, Jenny; Elliott, Matthew; di Maira, Giovanni; Gianoncelli, Alessandra; Pagano, Mario A; Sarno, Stefania; Ruzzene, Maria; Battistutta, Roberto; Meggio, Flavio; Moro, Stefano; Zagotto, Giuseppe; Pinna, Lorenzo A

    2009-08-01

    Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a moderately potent and poorly selective inhibitor of protein kinase CK2, one of the most pleiotropic serine/threonine protein kinases, implicated in neoplasia and in other global diseases. By virtual screening of the MMS (Molecular Modeling Section) database, we have now identified quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) as an inhibitor of CK2 that is more potent and selective than emodin. CK2 inhibition by quinalizarin is competitive with respect to ATP, with a Ki value of approx. 50 nM. Tested at 1 microM concentration on a panel of 75 protein kinases, quinalizarin drastically inhibits only CK2, with a promiscuity score (11.1), which is the lowest ever reported so far for a CK2 inhibitor. Especially remarkable is the ability of quinalizarin to discriminate between CK2 and a number of kinases, notably DYRK1a (dual-specificity tyrosine-phosphorylated and -regulated kinase), PIM (provirus integration site for Moloney murine leukaemia virus) 1, 2 and 3, HIPK2 (homeodomain-interacting protein kinase-2), MNK1 [MAPK (mitogen-activated protein kinase)-interacting kinase 1], ERK8 (extracellular-signal-regulated kinase 8) and PKD1 (protein kinase D 1), which conversely tend to be inhibited as drastically as CK2 by commercially available CK2 inhibitors. The determination of the crystal structure of a complex between quinalizarin and CK2alpha subunit highlights the relevance of polar interactions in stabilizing the binding, an unusual characteristic for a CK2 inhibitor, and disclose other structural features which may account for the narrow selectivity of this compound. Tested on Jurkat cells, quinalizarin proved able to inhibit endogenous CK2 and to induce apoptosis more efficiently than the commonly used CK2 inhibitors TBB (4,5,6,7-tetrabromo-1H-benzotriazole) and DMAT (2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole). PMID:19432557

  3. Structure and function based design of Plasmodium-selective proteasome inhibitors

    PubMed Central

    Li, Hao; O'Donoghue, Anthony J.; van der Linden, Wouter A.; Xie, Stanley C.; Yoo, Euna; Foe, Ian T.; Tilley, Leann; Craik, Charles S.; da Fonseca, Paula C. A.; Bogyo, Matthew

    2016-01-01

    The proteasome is a multi-component protease complex responsible for regulating key processes such as the cell cycle and antigen presentation1. Compounds that target the proteasome are potentially valuable tools for the treatment of pathogens that depend on proteasome function for survival and replication. In particular, proteasome inhibitors have been shown to be toxic for the malaria parasite Plasmodium falciparum at all stages of its life cycle2-5. Most compounds that have been tested against the parasite also inhibit the mammalian proteasome resulting in toxicity that precludes their use as therapeutic agents2,6. Therefore, better definition of the substrate specificity and structural properties of the Plasmodium proteasome could enable the development of compounds with sufficient selectivity to allow their use as anti-malarial agents. To accomplish this goal, we used a substrate profiling method to uncover differences in the specificities of the human and P. falciparum proteasome. We designed inhibitors based on amino acid preferences specific to the parasite proteasome, and found that they preferentially inhibit the β 2 subunit. We determined the structure of the P. falciparum 20S proteasome bound to the inhibitor using cryo-electron microscopy (cryo-EM) and single particle analysis, to a resolution of 3.6 Å. These data reveal the unusually open P. falciparum β2 active site and provide valuable information regarding active site architecture that can be used to further refine inhibitor design. Furthermore, consistent with the recent finding that the proteasome is important for stress pathways associated with resistance of artemisinin (ART) family anti-malarials7,8, we observed growth inhibition synergism with low doses of this β 2 selective inhibitor in ART sensitive and resistant parasites. Finally, we demonstrated that a parasite selective inhibitor could be used to attenuate parasite growth in vivo without significant toxicity to the host. Thus, the

  4. Pyrazolo-Pyrimidines: A Novel Heterocyclic Scaffold for Potent and Selective p38alpha Inhibitors

    SciTech Connect

    Das,J.; Moquin, R.; Pitt, S.; Zhang, R.; Shen, D.; McIntyre, K.; Gillooly, K.; Doweyko, A.; Sack, J.; et al

    2008-01-01

    The synthesis and structure-activity relationships (SAR) of p38a MAP kinase inhibitors based on a pyrazolo-pyrimidine scaffold are described. These studies led to the identification of compound 2x as a potent and selective inhibitor of p38a MAP kinase with excellent cellular potency toward the inhibition of TNFa production. Compound 2x was highly efficacious in vivo in inhibiting TNFa production in an acute murine model of TNFa production. X-ray co-crystallography of a pyrazolo-pyrimidine analog 2b bound to unphosphorylated p38a is also disclosed.

  5. Potent, selective and orally bioavailable leucine-rich repeat kinase 2 (LRRK2) inhibitors.

    PubMed

    Greshock, Thomas J; Sanders, John M; Drolet, Robert E; Rajapakse, Hemaka A; Chang, Ronald K; Kim, Boyoung; Rada, Vanessa L; Tiscia, Heather E; Su, Hua; Lai, Ming-Tain; Sur, Sylvie M; Sanchez, Rosa I; Bilodeau, Mark T; Renger, John J; Kern, Jonathan T; McCauley, John A

    2016-06-01

    Familial Parkinson's disease cases have recently been associated with the leucine rich repeat kinase 2 (LRRK2) gene. It has been hypothesized that inhibition of the LRRK2 protein may have the potential to alter disease pathogenesis. A dihydrobenzothiophene series of potent, selective, orally bioavailable LRRK2 inhibitors were identified from a high-throughput screen of the internal Merck sample collection. Initial SAR studies around the core established the series as a tractable small molecule lead series of LRRK2 inhibitors for potential treatment of Parkinson's disease. It was also found that incorporation of a lactam into the core drastically improved the CNS and DMPK properties of these small molecules. PMID:27106707

  6. 5-Amino-pyrazoles as potent and selective p38[alpha] inhibitors

    SciTech Connect

    Das, Jagabandhu; Moquin, Robert V.; Dyckman, Alaric J.; Li, Tianle; Pitt, Sidney; Zhang, Rosemary; Shen, Ding Ren; McIntyre, Kim W.; Gillooly, Kathleen; Doweyko, Arthur M.; Newitt, John A.; Sack, John S.; Zhang, Hongjian; Kiefer, Susan E.; Kish, Kevin; McKinnon, Murray; Barrish, Joel C.; Dodd, John H.; Schieven, Gary L.; Leftheris, Katerina

    2012-02-07

    The synthesis and structure-activity relationships (SAR) of p38{alpha} MAP kinase inhibitors based on a 5-amino-pyrazole scaffold are described. These studies led to the identification of compound 2j as a potent and selective inhibitor of p38{alpha} MAP kinase with excellent cellular potency toward the inhibition of TNF{alpha} production. Compound 2j was highly efficacious in vivo in inhibiting TNF{alpha} production in an acute murine model of TNF{alpha} production. X-ray co-crystallography of a 5-amino-pyrazole analog 2f bound to unphosphorylated p38{alpha} is also disclosed.

  7. The discovery of 2-substituted phenol quinazolines as potent RET kinase inhibitors with improved KDR selectivity.

    PubMed

    Newton, Rebecca; Bowler, Katherine A; Burns, Emily M; Chapman, Philip J; Fairweather, Emma E; Fritzl, Samantha J R; Goldberg, Kristin M; Hamilton, Niall M; Holt, Sarah V; Hopkins, Gemma V; Jones, Stuart D; Jordan, Allan M; Lyons, Amanda J; Nikki March, H; McDonald, Neil Q; Maguire, Laura A; Mould, Daniel P; Purkiss, Andrew G; Small, Helen F; Stowell, Alexandra I J; Thomson, Graeme J; Waddell, Ian D; Waszkowycz, Bohdan; Watson, Amanda J; Ogilvie, Donald J

    2016-04-13

    Deregulation of the receptor tyrosine kinase RET has been implicated in medullary thyroid cancer, a small percentage of lung adenocarcinomas, endocrine-resistant breast cancer and pancreatic cancer. There are several clinically approved multi-kinase inhibitors that target RET as a secondary pharmacology but additional activities, most notably inhibition of KDR, lead to dose-limiting toxicities. There is, therefore, a clinical need for more specific RET kinase inhibitors. Herein we report our efforts towards identifying a potent and selective RET inhibitor using vandetanib 1 as the starting point for structure-based drug design. Phenolic anilinoquinazolines exemplified by 6 showed improved affinities towards RET but, unsurprisingly, suffered from high metabolic clearance. Efforts to mitigate the metabolic liability of the phenol led to the discovery that a flanking substituent not only improved the hepatocyte stability, but could also impart a significant gain in selectivity. This culminated in the identification of 36; a potent RET inhibitor with much improved selectivity against KDR. PMID:26874741

  8. Structural Characterization of Inhibitors with Selectivity against Members of a Homologous Enzyme Family

    SciTech Connect

    Pavlovsky, Alexander G.; Liu, Xuying; Faehnle, Christopher R.; Potente, Nina; Viola, Ronald E.

    2013-01-31

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. As this critical pathway is only present in plants and microbes, any disruptions will be fatal to these organisms. An early pathway enzyme, L-aspartate-{beta}-semialdehyde dehydrogenase, produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the L-aspartate-{beta}-semialdehyde dehydrogenase family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against L-aspartate-{beta}-semialdehyde dehydrogenases from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure-guided approach to the development of more potent and more selective inhibitors.

  9. Structural Characterization of Inhibitors with Selectivity against Members of a Homologous Enzyme Family

    PubMed Central

    Pavlovsky, Alexander G.; Liu, Xuying; Faehnle, Christopher R.; Potente, Nina; Viola, Ronald E.

    2012-01-01

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. Since this critical pathway is only present in plants and microbes any disruptions will be fatal to these organisms. An early pathway enzyme, L-aspartate-β-semialdehyde dehydrogenase (ASADH), produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the ASADH family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against ASADHs from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure guided approach to the development of more potent and more selective inhibitors. PMID:22039970

  10. Structural characterization of inhibitors with selectivity against members of a homologous enzyme family.

    PubMed

    Pavlovsky, Alexander G; Liu, Xuying; Faehnle, Christopher R; Potente, Nina; Viola, Ronald E

    2012-01-01

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. As this critical pathway is only present in plants and microbes, any disruptions will be fatal to these organisms. An early pathway enzyme, l-aspartate-β-semialdehyde dehydrogenase, produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the l-aspartate-β-semialdehyde dehydrogenase family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against l-aspartate-β-semialdehyde dehydrogenases from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure-guided approach to the development of more potent and more selective inhibitors. PMID:22039970

  11. Accessible Chiral Linker to Enhance Potency and Selectivity of Neuronal Nitric Oxide Synthase Inhibitors

    PubMed Central

    2013-01-01

    The three important mammalian isozymes of nitric oxide synthase (NOS) are neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Inhibitors of nNOS show promise as treatments for neurodegenerative diseases. Eight easily synthesized compounds containing either one (20a,b) or two (9a–d; 15a,b) 2-amino-4-methylpyridine groups with a chiral pyrrolidine linker were designed as selective nNOS inhibitors. Inhibitor 9c is the best of these compounds, having a potency of 9.7 nM and dual selectivity of 693 and 295 against eNOS and iNOS, respectively. Crystal structures of nNOS complexed with either 9a or 9c show a double-headed binding mode, where each 2-aminopyridine headgroup interacts with either a nNOS active site Glu residue or a heme propionate. In addition, the pyrrolidine nitrogen of 9c contributes additional hydrogen bonds to the heme propionate, resulting in a unique binding orientation. In contrast, the lack of hydrogen bonds from the pyrrolidine of 9a to the heme propionate allows the inhibitor to adopt two different binding orientations. Both 9a and 9c bind to eNOS in a single-headed mode, which is the structural basis for the isozyme selectivity. PMID:24660051

  12. Inhibitors of Glycogen Synthase Kinase 3 with Exquisite Kinome-Wide Selectivity and Their Functional Effects.

    PubMed

    Wagner, Florence F; Bishop, Joshua A; Gale, Jennifer P; Shi, Xi; Walk, Michelle; Ketterman, Joshua; Patnaik, Debasis; Barker, Doug; Walpita, Deepika; Campbell, Arthur J; Nguyen, Shannon; Lewis, Michael; Ross, Linda; Weïwer, Michel; An, W Frank; Germain, Andrew R; Nag, Partha P; Metkar, Shailesh; Kaya, Taner; Dandapani, Sivaraman; Olson, David E; Barbe, Anne-Laure; Lazzaro, Fanny; Sacher, Joshua R; Cheah, Jaime H; Fei, David; Perez, Jose; Munoz, Benito; Palmer, Michelle; Stegmaier, Kimberly; Schreiber, Stuart L; Scolnick, Edward; Zhang, Yan-Ling; Haggarty, Stephen J; Holson, Edward B; Pan, Jen Q

    2016-07-15

    The mood stabilizer lithium, the first-line treatment for bipolar disorder, is hypothesized to exert its effects through direct inhibition of glycogen synthase kinase 3 (GSK3) and indirectly by increasing GSK3's inhibitory serine phosphorylation. GSK3 comprises two highly similar paralogs, GSK3α and GSK3β, which are key regulatory kinases in the canonical Wnt pathway. GSK3 stands as a nodal target within this pathway and is an attractive therapeutic target for multiple indications. Despite being an active field of research for the past 20 years, many GSK3 inhibitors demonstrate either poor to moderate selectivity versus the broader human kinome or physicochemical properties unsuitable for use in in vitro systems or in vivo models. A nonconventional analysis of data from a GSK3β inhibitor high-throughput screening campaign, which excluded known GSK3 inhibitor chemotypes, led to the discovery of a novel pyrazolo-tetrahydroquinolinone scaffold with unparalleled kinome-wide selectivity for the GSK3 kinases. Taking advantage of an uncommon tridentate interaction with the hinge region of GSK3, we developed highly selective and potent GSK3 inhibitors, BRD1652 and BRD0209, which demonstrated in vivo efficacy in a dopaminergic signaling paradigm modeling mood-related disorders. These new chemical probes open the way for exclusive analyses of the function of GSK3 kinases in multiple signaling pathways involved in many prevalent disorders. PMID:27128528

  13. Characteristics of new P2Y12 inhibitors: selection of P2Y12 inhibitors in clinical practice.

    PubMed

    Golino, Paolo

    2013-12-01

    The options for antithrombotic therapy have recently been expanded, facilitating optimal tailored treatment. Dual antiplatelet therapy with aspirin and an approved adenosine diphosphate P2Y12 receptor antagonist is recommended for the management of patients with acute coronary syndromes (ACS). However, there are a number of controversies: which P2Y12 inhibitor to choose; how long should antiplatelet therapy be used so as to prevent thrombotic events and minimize bleeding risks; whether to use drug-eluting (DES) or bare-metal stents (BMS) and how to manage the individual variability in response to clopidogrel. Clopidogrel in combination with aspirin has been the standard dual antiplatelet regimen for ACS. The new, more potent P2Y12 inhibitors, prasugrel and ticagrelor, have shown improved antithrombotic effects compared with clopidogrel in patients with ACS (with or without ST-segment elevation myocardial infarction) in landmark trials, even if they were associated with an increased risk of major bleeding. Different pharmacogenetic and pharmacodynamic characteristics may explain, in part, the different pharmacologic and clinical responses to these antiplatelet agents. Importantly, both clopidogrel and prasugrel are prodrugs, i.e., they need to be converted in vivo into active metabolites that selectively and irreversibly bind the P2Y12 receptor. Unlike clopidogrel, however, common functional cytochrome P450 genetic variants do not affect prasugrel active metabolite levels or inhibition of platelet aggregation. In contrast, ticagrelor is not a prodrug (i.e., does not require hepatic metabolism to exert its antiplatelet effect) and represents the first oral P2Y12 receptor antagonist that is reversibly bound. Similar to prasugrel, ticagrelor achieves greater and more rapid inhibition of platelet function than clopidogrel. Evidence suggests that the new P2Y12 antagonists may offer improved antithrombotic effects compared with clopidogrel in selected patients for the

  14. General Ser/Thr Kinases Pharmacophore Approach for Selective Kinase Inhibitors Search as Exemplified by Design of Potent and Selective Aurora A Inhibitors.

    PubMed

    Vasilevich, Natalya I; Aksenova, Elena A; Kazyulkin, Denis N; Afanasyev, Ilya I

    2016-07-01

    A general pharmachophore model for various types of Ser/Thr kinases was developed. Search for the molecules fitting to this pharmacophore among ASINEX proprietary library revealed a number of compounds, which were tested and appeared to possess some activity against several Ser/Thr kinases such as Aurora A, Aurora B and Haspin. The possibility of performing the fine-tuning of the general Ser/Thr pharmacophore to desired types of kinase to get active and selective inhibitors was exemplified by Aurora A kinase. As a result, several hits in 3-5 nm range of activity against Aurora A kinase with rather good selectivity and ADME properties were obtained. PMID:26825399

  15. (R)-2-Phenylpyrrolidine Substituted Imidazopyridazines: A New Class of Potent and Selective Pan-TRK Inhibitors

    PubMed Central

    2015-01-01

    Deregulated kinase activities of tropomyosin receptor kinase (TRK) family members have been shown to be associated with tumorigenesis and poor prognosis in a variety of cancer types. In particular, several chromosomal rearrangements involving TRKA have been reported in colorectal, papillary thyroid, glioblastoma, melanoma, and lung tissue that are believed to be the key oncogenic driver in these tumors. By screening the Novartis compound collection, a novel imidazopyridazine TRK inhibitor was identified that served as a launching point for drug optimization. Structure guided drug design led to the identification of (R)-2-phenylpyrrolidine substituted imidazopyridazines as a series of potent, selective, orally bioavailable pan-TRK inhibitors achieving tumor regression in rats bearing KM12 xenografts. From this work the (R)-2-phenylpyrrolidine has emerged as an ideal moiety to incorporate in bicyclic TRK inhibitors by virtue of its shape complementarity to the hydrophobic pocket of TRKs. PMID:26005534

  16. Design and Synthesis of Phenylpyrrolidine Phenylglycinamides As Highly Potent and Selective TF-FVIIa Inhibitors

    PubMed Central

    2013-01-01

    Inhibitors of the Tissue Factor/Factor VIIa (TF-FVIIa) complex are promising novel anticoagulants that show excellent efficacy and minimal bleeding in preclinical models. On the basis of a zwitterionic phenylglycine acylsulfonamide 1, a phenylglycine benzylamide 2 was shown to possess improved permeability and oral bioavailability. Optimization of the benzylamide, guided by X-ray crystallography, led to a potent TF-FVIIa inhibitor 18i with promising oral bioavailability, but promiscuous activity in an in vitro safety panel of receptors and enzymes. Introducing an acid on the pyrrolidine ring, guided by molecular modeling, resulted in highly potent, selective, and efficacious TF-FVIIa inhibitors with clean in vitro safety profile. The pyrrolidine acid 20 showed a moderate clearance, low volume of distribution, and a short t1/2 in dog PK studies. PMID:24900796

  17. Design of inhibitors of thymidylate kinase from Variola virus as new selective drugs against smallpox.

    PubMed

    Guimarães, Ana P; de Souza, Felipe R; Oliveira, Aline A; Gonçalves, Arlan S; de Alencastro, Ricardo B; Ramalho, Teodorico C; França, Tanos C C

    2015-02-16

    Recently we constructed a homology model of the enzyme thymidylate kinase from Variola virus (VarTMPK) and proposed it as a new target to the drug design against smallpox. In the present work, we used the antivirals cidofovir and acyclovir as reference compounds to choose eleven compounds as leads to the drug design of inhibitors for VarTMPK. Docking and molecular dynamics (MD) studies of the interactions of these compounds inside VarTMPK and human TMPK (HssTMPK) suggest that they compete for the binding region of the substrate and were used to propose the structures of ten new inhibitors for VarTMPK. Further docking and MD simulations of these compounds, inside VarTMPK and HssTMPK, suggest that nine among ten are potential selective inhibitors of VarTMPK. PMID:25458183

  18. 6-thioguanine selectively kills BRCA2 defective tumours and overcomes PARP inhibitor resistance

    PubMed Central

    Issaeva, Natalia; Thomas, Huw D.; Djurenovic, Tatjana; Jaspers, Janneke E.; Stoimenov, Ivaylo; Kyle, Suzanne; Pedley, Nicholas; Gottipati, Ponnari; Zur, Rafal; Sleeth, Kate; Chatzakos, Vicky; Mulligan, Evan; Lundin, Cecilia; Gubanova, Evgenia; Kersbergen, Ariena; Harris, Adrian L; Sharma, Ricky A; Rottenberg, Sven; Curtin, Nicola J.; Helleday, Thomas

    2010-01-01

    Familial breast and ovarian cancers are often defective in homologous recombination (HR) due to mutations in the BRCA1 or BRCA2 genes. Cisplatin chemotherapy or poly(ADP-ribose) polymerase (PARP) inhibitors are tested for these tumours in clinical trials. In a screen for novel drugs that selectively kill BRCA2-defective cells, we identified 6-thioguanine (6TG), which induces DNA double-strand breaks (DSBs) that we show are repaired by HR. Furthermore, we show that 6TG is as efficient as a PARP inhibitor in selectively killing BRCA2-defective tumours in a xenograft model. Spontaneous BRCA1 defective mammary tumours gain resistance to PARP inhibitors through increased p-glycoprotein expression. Here, we show that 6TG efficiently kills such BRCA1 defective PARP inhibitor resistant (PIR) tumours. We also show that 6TG can kill cells and tumours that have gained resistance to PARP inhibitors or cisplatin through genetic reversion of the BRCA2 gene. Although HR is reactivated in PIR BRCA2-defective cells, it is not fully restored for the repair of 6TG-induced lesions. This is likely to be due to several recombinogenic lesions being formed after 6TG. We show that BRCA2 is required for survival also to mismatch repair-independent lesions formed by 6TG, which do not include DSBs. This suggests that HR is involved in repair of 6TG-induced DSBs as well as mismatch repair-independent 6TG-induced DNA lesion. Altogether, our data show that 6TG efficiently kills BRCA2-defective tumours and suggest that 6TG may be effective in the treatment of advanced tumours that have developed resistance to PARP inhibitors or platinum-based chemotherapy. PMID:20631063

  19. Potent and Selective Inhibition of Plasma Membrane Monoamine Transporter by HIV Protease Inhibitors.

    PubMed

    Duan, Haichuan; Hu, Tao; Foti, Robert S; Pan, Yongmei; Swaan, Peter W; Wang, Joanne

    2015-11-01

    Plasma membrane monoamine transporter (PMAT) is a major uptake-2 monoamine transporter that shares extensive substrate and inhibitor overlap with organic cation transporters 1-3 (OCT1-3). Currently, there are no PMAT-specific inhibitors available that can be used in in vitro and in vivo studies to differentiate between PMAT and OCT activities. In this study, we showed that IDT307 (4-(4-(dimethylamino)phenyl)-1-methylpyridinium iodide), a fluorescent analog of 1-methyl-4-phenylpyridinium (MPP+), is a transportable substrate for PMAT and that IDT307-based fluorescence assay can be used to rapidly identify and characterize PMAT inhibitors. Using the fluorescent substrate-based assays, we analyzed the interactions of eight human immunodeficiency virus (HIV) protease inhibitors (PIs) with human PMAT and OCT1-3 in human embryonic kidney 293 (HEK293) cells stably transfected with individual transporters. Our data revealed that PMAT and OCTs exhibit distinct sensitivity and inhibition patterns toward HIV PIs. PMAT is most sensitive to PI inhibition whereas OCT2 and OCT3 are resistant. OCT1 showed an intermediate sensitivity and a distinct inhibition profile from PMAT. Importantly, lopinavir is a potent PMAT inhibitor and exhibited >120 fold selectivity toward PMAT (IC₅₀ = 1.4 ± 0.2 µM) over OCT1 (IC₅₀ = 174 ± 40 µM). Lopinavir has no inhibitory effect on OCT2 or OCT3 at maximal tested concentrations. Lopinavir also exhibited no or much weaker interactions with uptake-1 monoamine transporters. Together, our results reveal that PMAT and OCTs have distinct specificity exemplified by their differential interaction with HIV PIs. Further, we demonstrate that lopinavir can be used as a selective PMAT inhibitor to differentiate PMAT-mediated monoamine and organic cation transport from those mediated by OCT1-3. PMID:26285765

  20. Effects of Isoform-selective Phosphatidylinositol 3-Kinase Inhibitors on Osteoclasts

    PubMed Central

    Shugg, Ryan P. P.; Thomson, Ashley; Tanabe, Natsuko; Kashishian, Adam; Steiner, Bart H.; Puri, Kamal D.; Pereverzev, Alexey; Lannutti, Brian J.; Jirik, Frank R.; Dixon, S. Jeffrey; Sims, Stephen M.

    2013-01-01

    Phosphatidylinositol 3-kinases (PI3K) participate in numerous signaling pathways, and control distinct biological functions. Studies using pan-PI3K inhibitors suggest roles for PI3K in osteoclasts, but little is known about specific PI3K isoforms in these cells. Our objective was to determine effects of isoform-selective PI3K inhibitors on osteoclasts. The following inhibitors were investigated (targets in parentheses): wortmannin and LY294002 (pan-p110), PIK75 (α), GDC0941 (α, δ), TGX221 (β), AS252424 (γ), and IC87114 (δ). In addition, we characterized a new potent and selective PI3Kδ inhibitor, GS-9820, and explored roles of PI3K isoforms in regulating osteoclast function. Osteoclasts were isolated from long bones of neonatal rats and rabbits. Wortmannin, LY294002, GDC0941, IC87114, and GS-9820 induced a dramatic retraction of osteoclasts within 15–20 min to 65–75% of the initial area. In contrast, there was no significant retraction in response to vehicle, PIK75, TGX221, or AS252424. Moreover, wortmannin and GS-9820, but not PIK75 or TGX221, disrupted actin belts. We examined effects of PI3K inhibitors on osteoclast survival. Whereas PIK75, TGX221, and GS-9820 had no significant effect on basal survival, all blocked RANKL-stimulated survival. When studied on resorbable substrates, osteoclastic resorption was suppressed by wortmannin and inhibitors of PI3Kβ and PI3Kδ, but not other isoforms. These data are consistent with a critical role for PI3Kδ in regulating osteoclast cytoskeleton and resorptive activity. In contrast, multiple PI3K isoforms contribute to the control of osteoclast survival. Thus, the PI3Kδ isoform, which is predominantly expressed in cells of hematopoietic origin, is an attractive target for anti-resorptive therapeutics. PMID:24133210

  1. Preclinical testing of selective Aurora kinase inhibitors on a medullary thyroid carcinoma-derived cell line.

    PubMed

    Tuccilli, Chiara; Baldini, Enke; Prinzi, Natalie; Morrone, Stefania; Sorrenti, Salvatore; Filippini, Angelo; Catania, Antonio; Alessandrini, Stefania; Rendina, Roberta; Coccaro, Carmela; D'Armiento, Massimino; Ulisse, Salvatore

    2016-05-01

    Deregulated expression of the Aurora kinases (Aurora-A, B, and C) is thought to be involved in cell malignant transformation and genomic instability in several cancer types. Over the last decade, a number of small-molecule inhibitors of Aurora kinases have been developed, which have proved to efficiently restrain malignant cell growth and tumorigenicity. Regarding medullary thyroid carcinoma (MTC), we previously showed the efficacy of a pan-Aurora kinase inhibitor (MK-0457) in impairing growth and survival of the MTC-derived cell line TT. In the present study, we sought to establish if one of the Aurora kinases might represent a preferential target for MTC therapy. The effects of selective inhibitors of Aurora-A (MLN8237) and Aurora-B (AZD1152) were analyzed on TT cell proliferation, apoptosis, cell cycle, and ploidy. The two inhibitors reduced TT cell proliferation in a time- and dose-dependent manner, with IC50 of 19.0 ± 2.4 nM for MLN8237 and 401.6 ± 44.1 nM for AZD1152. Immunofluorescence experiments confirmed that AZD1152 inhibited phosphorylation of histone H3 (Ser10) by Aurora-B, while it did not affect Aurora-A autophosphorylation. MLN8237 inhibited Aurora-A autophosphorylation as expected, but at concentrations required to achieve the maximum antiproliferative effects it also abolished H3 (Ser10) phosphorylation. Cytofluorimetry experiments showed that both inhibitors induced accumulation of cells in G2/M phase and increased the subG0/G1 fraction and polyploidy. Finally, both inhibitors triggered apoptosis. We demonstrated that inhibition of either Aurora-A or Aurora-B has antiproliferative effects on TT cells, and thus it would be worthwhile to further investigate the therapeutical potential of Aurora kinase inhibitors in MTC treatment. PMID:26215279

  2. Identification of Genes Conferring Tolerance to Lignocellulose-Derived Inhibitors by Functional Selections in Soil Metagenomes.

    PubMed

    Forsberg, Kevin J; Patel, Sanket; Witt, Evan; Wang, Bin; Ellison, Tyler D; Dantas, Gautam

    2016-01-01

    The production of fuels or chemicals from lignocellulose currently requires thermochemical pretreatment to release fermentable sugars. These harsh conditions also generate numerous small-molecule inhibitors of microbial growth and fermentation, limiting production. We applied small-insert functional metagenomic selections to discover genes that confer microbial tolerance to these inhibitors, identifying both individual genes and general biological processes associated with tolerance to multiple inhibitory compounds. Having screened over 248 Gb of DNA cloned from 16 diverse soil metagenomes, we describe gain-of-function tolerance against acid, alcohol, and aldehyde inhibitors derived from hemicellulose and lignin, demonstrating that uncultured soil microbial communities hold tremendous genetic potential to address the toxicity of pretreated lignocellulose. We recovered genes previously known to confer tolerance to lignocellulosic inhibitors as well as novel genes that confer tolerance via unknown functions. For instance, we implicated galactose metabolism in overcoming the toxicity of lignin monomers and identified a decarboxylase that confers tolerance to ferulic acid; this enzyme has been shown to catalyze the production of 4-vinyl guaiacol, a valuable precursor to vanillin production. These metagenomic tolerance genes can enable the flexible design of hardy microbial catalysts, customized to withstand inhibitors abundant in specific bioprocessing applications. PMID:26546427

  3. Identification of Genes Conferring Tolerance to Lignocellulose-Derived Inhibitors by Functional Selections in Soil Metagenomes

    PubMed Central

    Forsberg, Kevin J.; Patel, Sanket; Witt, Evan; Wang, Bin; Ellison, Tyler D.

    2015-01-01

    The production of fuels or chemicals from lignocellulose currently requires thermochemical pretreatment to release fermentable sugars. These harsh conditions also generate numerous small-molecule inhibitors of microbial growth and fermentation, limiting production. We applied small-insert functional metagenomic selections to discover genes that confer microbial tolerance to these inhibitors, identifying both individual genes and general biological processes associated with tolerance to multiple inhibitory compounds. Having screened over 248 Gb of DNA cloned from 16 diverse soil metagenomes, we describe gain-of-function tolerance against acid, alcohol, and aldehyde inhibitors derived from hemicellulose and lignin, demonstrating that uncultured soil microbial communities hold tremendous genetic potential to address the toxicity of pretreated lignocellulose. We recovered genes previously known to confer tolerance to lignocellulosic inhibitors as well as novel genes that confer tolerance via unknown functions. For instance, we implicated galactose metabolism in overcoming the toxicity of lignin monomers and identified a decarboxylase that confers tolerance to ferulic acid; this enzyme has been shown to catalyze the production of 4-vinyl guaiacol, a valuable precursor to vanillin production. These metagenomic tolerance genes can enable the flexible design of hardy microbial catalysts, customized to withstand inhibitors abundant in specific bioprocessing applications. PMID:26546427

  4. Elaboration of a fragment library hit produces potent and selective aspartate semialdehyde dehydrogenase inhibitors.

    PubMed

    Thangavelu, Bharani; Bhansali, Pravin; Viola, Ronald E

    2015-10-15

    Aspartate-β-semialdehyde dehydrogenase (ASADH) lies at the first branch point in the aspartate metabolic pathway which leads to the biosynthesis of several essential amino acids and some important metabolites. This pathway is crucial for many metabolic processes in plants and microbes like bacteria and fungi, but is absent in mammals. Therefore, the key microbial enzymes involved in this pathway are attractive potential targets for development of new antibiotics with novel modes of action. The ASADH enzyme family shares the same substrate binding and active site catalytic groups; however, the enzymes from representative bacterial and fungal species show different inhibition patterns when previously screened against low molecular weight inhibitors identified from fragment library screening. In the present study several approaches, including fragment based drug discovery (FBDD), inhibitor docking, kinetic, and structure-activity relationship (SAR) studies have been used to guide ASADH inhibitor development. Elaboration of a core structure identified by FBDD has led to the synthesis of low micromolar inhibitors of the target enzyme, with high selectivity introduced between the Gram-negative and Gram-positive orthologs of ASADH. This new set of structures open a novel direction for the development of inhibitors against this validated drug-target enzyme. PMID:26404410

  5. Discovery and characterization of a potent and selective inhibitor of Aedes aegypti inward rectifier potassium channels.

    PubMed

    Raphemot, Rene; Rouhier, Matthew F; Swale, Daniel R; Days, Emily; Weaver, C David; Lovell, Kimberly M; Konkel, Leah C; Engers, Darren W; Bollinger, Sean R; Bollinger, Sean F; Hopkins, Corey; Piermarini, Peter M; Denton, Jerod S

    2014-01-01

    Vector-borne diseases such as dengue fever and malaria, which are transmitted by infected female mosquitoes, affect nearly half of the world's population. The emergence of insecticide-resistant mosquito populations is reducing the effectiveness of conventional insecticides and threatening current vector control strategies, which has created an urgent need to identify new molecular targets against which novel classes of insecticides can be developed. We previously demonstrated that small molecule inhibitors of mammalian Kir channels represent promising chemicals for new mosquitocide development. In this study, high-throughput screening of approximately 30,000 chemically diverse small-molecules was employed to discover potent and selective inhibitors of Aedes aegypti Kir1 (AeKir1) channels heterologously expressed in HEK293 cells. Of 283 confirmed screening 'hits', the small-molecule inhibitor VU625 was selected for lead optimization and in vivo studies based on its potency and selectivity toward AeKir1, and tractability for medicinal chemistry. In patch clamp electrophysiology experiments of HEK293 cells, VU625 inhibits AeKir1 with an IC50 value of 96.8 nM, making VU625 the most potent inhibitor of AeKir1 described to date. Furthermore, electrophysiology experiments in Xenopus oocytes revealed that VU625 is a weak inhibitor of AeKir2B. Surprisingly, injection of VU625 failed to elicit significant effects on mosquito behavior, urine excretion, or survival. However, when co-injected with probenecid, VU625 inhibited the excretory capacity of mosquitoes and was toxic, suggesting that the compound is a substrate of organic anion and/or ATP-binding cassette (ABC) transporters. The dose-toxicity relationship of VU625 (when co-injected with probenecid) is biphasic, which is consistent with the molecule inhibiting both AeKir1 and AeKir2B with different potencies. This study demonstrates proof-of-concept that potent and highly selective inhibitors of mosquito Kir channels can

  6. Discovery and Characterization of a Potent and Selective Inhibitor of Aedes aegypti Inward Rectifier Potassium Channels

    PubMed Central

    Raphemot, Rene; Rouhier, Matthew F.; Swale, Daniel R.; Days, Emily; Weaver, C. David; Lovell, Kimberly M.; Konkel, Leah C.; Engers, Darren W.; Bollinger, Sean F.; Hopkins, Corey; Piermarini, Peter M.; Denton, Jerod S.

    2014-01-01

    Vector-borne diseases such as dengue fever and malaria, which are transmitted by infected female mosquitoes, affect nearly half of the world's population. The emergence of insecticide-resistant mosquito populations is reducing the effectiveness of conventional insecticides and threatening current vector control strategies, which has created an urgent need to identify new molecular targets against which novel classes of insecticides can be developed. We previously demonstrated that small molecule inhibitors of mammalian Kir channels represent promising chemicals for new mosquitocide development. In this study, high-throughput screening of approximately 30,000 chemically diverse small-molecules was employed to discover potent and selective inhibitors of Aedes aegypti Kir1 (AeKir1) channels heterologously expressed in HEK293 cells. Of 283 confirmed screening ‘hits’, the small-molecule inhibitor VU625 was selected for lead optimization and in vivo studies based on its potency and selectivity toward AeKir1, and tractability for medicinal chemistry. In patch clamp electrophysiology experiments of HEK293 cells, VU625 inhibits AeKir1 with an IC50 value of 96.8 nM, making VU625 the most potent inhibitor of AeKir1 described to date. Furthermore, electrophysiology experiments in Xenopus oocytes revealed that VU625 is a weak inhibitor of AeKir2B. Surprisingly, injection of VU625 failed to elicit significant effects on mosquito behavior, urine excretion, or survival. However, when co-injected with probenecid, VU625 inhibited the excretory capacity of mosquitoes and was toxic, suggesting that the compound is a substrate of organic anion and/or ATP-binding cassette (ABC) transporters. The dose-toxicity relationship of VU625 (when co-injected with probenecid) is biphasic, which is consistent with the molecule inhibiting both AeKir1 and AeKir2B with different potencies. This study demonstrates proof-of-concept that potent and highly selective inhibitors of mosquito Kir channels

  7. Effect of soluble epoxide hydrolase polymorphism on substrate and inhibitor selectivity and dimer formation[S

    PubMed Central

    Morisseau, Christophe; Wecksler, Aaron T.; Deng, Catherine; Dong, Hua; Yang, Jun; Lee, Kin Sing S.; Kodani, Sean D.; Hammock, Bruce D.

    2014-01-01

    Epoxy FAs (EpFAs) are important lipid mediators that are mainly metabolized by soluble epoxide hydrolase (sEH). Thus, sEH inhibition is a promising therapeutic target to treat numerous ailments. Several sEH polymorphisms result in amino acid substitutions and alter enzyme activity. K55R and R287Q are associated with inflammatory, cardiovascular, and metabolic diseases. R287Q seems to affect sEH activity through reducing formation of a catalytically active dimer. Thus, understanding how these SNPs affect the selectivity of sEH for substrates and inhibitors is of potential clinical importance. We investigated the selectivity of four sEH SNPs toward a series of EpFAs and inhibitors. We found that the SNPs alter the catalytic activity of the enzyme but do not alter the relative substrate and inhibitor selectivity. We also determined their dimer/monomer constants (KD/M). The WT sEH formed a very tight dimer, with a KD/M in the low picomolar range. Only R287Q resulted in a large change of the KD/M. However, human tissue concentrations of sEH suggest that it is always in its dimer form independently of the SNP. These results suggest that the different biologies associated with K55R and R287Q are not explained by alteration in dimer formation or substrate selectivity. PMID:24771868

  8. A selective jumonji H3K27 demethylase inhibitor modulates the proinflammatory macrophage response

    PubMed Central

    Kruidenier, Laurens; Chung, Chun-wa; Cheng, Zhongjun; Liddle, John; Che, KaHing; Joberty, Gerard; Bantscheff, Marcus; Bountra, Chas; Bridges, Angela; Diallo, Hawa; Eberhard, Dirk; Hutchinson, Sue; Jones, Emma; Katso, Roy; Leveridge, Melanie; Mander, Palwinder K.; Mosley, Julie; Ramirez-Molina, Cesar; Rowland, Paul; Schofield, Christopher J.; Sheppard, Robert J.; Smith, Julia E.; Swales, Catherine; Tanner, Robert; Thomas, Pamela; Tumber, Anthony; Drewes, Gerard; Oppermann, Udo; Patel, Dinshaw J.; Lee, Kevin; Wilson, David M.

    2015-01-01

    The jumonji (JMJ) family of histone demethylases are Fe2+- and α-ketoglutarate-dependent oxygenases that are essential components of regulatory transcriptional chromatin complexes1–4. These enzymes demethylate lysine residues in histones in a methylation-state and sequence-specific context5. Considerable effort has been devoted to gaining a mechanistic understanding of the roles of histone lysine demethylases in eukaryotic transcription, genome integrity and epigenetic inheritance2,4,6, as well as in development, physiology and disease3,7. However, because of the absence of any selective inhibitors, the relevance of the demethylase activity of JMJ enzymes in regulating cellular responses remains poorly understood. Here we present a structure-guided small-molecule and chemoproteomics approach to elucidating the functional role of the H3K27me3-specific demethylase subfamily (KDM6 subfamily members JMJD3 and UTX)8. The liganded structures of human and mouse JMJD3 provide novel insight into the specificity determinants for cofactor, substrate and inhibitor recognition by the KDM6 subfamily of demethylases. We exploited these structural features to generate the first small-molecule catalytic site inhibitor that is selective for the H3K27me3-specific JMJ subfamily. We demonstrate that this inhibitor binds in a novel manner and reduces lipopolysaccharide-induced proinflammatory cytokine production by human primary macrophages, a process that depends on both JMJD3 and UTX. Our results resolve the ambiguity associated with the catalytic function of H3K27-specific JMJs in regulating disease-relevant inflammatory responses and provide encouragement for designing small-molecule inhibitors to allow selective pharmacological intervention across the JMJ family. PMID:22842901

  9. A selective jumonji H3K27 demethylase inhibitor modulates the proinflammatory macrophage response

    SciTech Connect

    Kruidenier, Laurens; Chung, Chun-wa; Cheng, Zhongjun; Liddle, John; Che, KaHing; Joberty, Gerard; Bantscheff, Marcus; Bountra, Chas; Bridges, Angela; Diallo, Hawa; Eberhard, Dirk; Hutchinson, Sue; Jones, Emma; Katso, Roy; Leveridge, Melanie; Mander, Palwinder K.; Mosley, Julie; Ramirez-Molina, Cesar; Rowland, Paul; Schofield, Christopher J.; Sheppard, Robert J.; Smith, Julia E.; Swales, Catherine; Tanner, Robert; Thomas, Pamela; Tumber, Anthony; Drewes, Gerard; Oppermann, Udo; Patel, Dinshaw J.; Lee, Kevin; Wilson, David M.

    2012-10-11

    The jumonji (JMJ) family of histone demethylases are Fe{sup 2+}- and {alpha}-ketoglutarate-dependent oxygenases that are essential components of regulatory transcriptional chromatin complexes. These enzymes demethylate lysine residues in histones in a methylation-state and sequence-specific context. Considerable effort has been devoted to gaining a mechanistic understanding of the roles of histone lysine demethylases in eukaryotic transcription, genome integrity and epigenetic inheritance, as well as in development, physiology and disease. However, because of the absence of any selective inhibitors, the relevance of the demethylase activity of JMJ enzymes in regulating cellular responses remains poorly understood. Here we present a structure-guided small-molecule and chemoproteomics approach to elucidating the functional role of the H3K27me3-specific demethylase subfamily (KDM6 subfamily members JMJD3 and UTX). The liganded structures of human and mouse JMJD3 provide novel insight into the specificity determinants for cofactor, substrate and inhibitor recognition by the KDM6 subfamily of demethylases. We exploited these structural features to generate the first small-molecule catalytic site inhibitor that is selective for the H3K27me3-specific JMJ subfamily. We demonstrate that this inhibitor binds in a novel manner and reduces lipopolysaccharide-induced proinflammatory cytokine production by human primary macrophages, a process that depends on both JMJD3 and UTX. Our results resolve the ambiguity associated with the catalytic function of H3K27-specific JMJs in regulating disease-relevant inflammatory responses and provide encouragement for designing small-molecule inhibitors to allow selective pharmacological intervention across the JMJ family.

  10. Discovery and optimization of sulfonyl acrylonitriles as selective, covalent inhibitors of protein phosphatase methylesterase-1.

    PubMed

    Bachovchin, Daniel A; Zuhl, Andrea M; Speers, Anna E; Wolfe, Monique R; Weerapana, Eranthie; Brown, Steven J; Rosen, Hugh; Cravatt, Benjamin F

    2011-07-28

    The serine hydrolase protein phosphatase methylesterase-1 (PME-1) regulates the methylesterification state of protein phosphatase 2A (PP2A) and has been implicated in cancer and Alzheimer's disease. We recently reported a fluorescence polarization-activity-based protein profiling (fluopol-ABPP) high-throughput screen for PME-1 that uncovered a remarkably potent and selective class of aza-β-lactam (ABL) PME-1 inhibitors. Here, we describe a distinct set of sulfonyl acrylonitrile inhibitors that also emerged from this screen. The optimized compound, 28 (AMZ30), selectively inactivates PME-1 and reduces the demethylated form of PP2A in living cells. Considering that 28 is structurally unrelated to ABL inhibitors of PME-1, these agents, together, provide a valuable set of pharmacological probes to study the role of methylation in regulating PP2A function. We furthermore observed that several serine hydrolases were sensitive to analogues of 28, suggesting that more extensive structural exploration of the sulfonyl acrylonitrile chemotype may result in useful inhibitors for other members of this large enzyme class. PMID:21639134

  11. A selective ATP-competitive sphingosine kinase inhibitor demonstrates anti-cancer properties

    PubMed Central

    Pitman, Melissa R.; Powell, Jason A.; Coolen, Carl; Moretti, Paul A.B.; Zebol, Julia R.; Pham, Duyen H.; Finnie, John W.; Don, Anthony S.; Ebert, Lisa M.; Bonder, Claudine S.; Gliddon, Briony L.; Pitson, Stuart M.

    2015-01-01

    The dynamic balance of cellular sphingolipids, the sphingolipid rheostat, is an important determinant of cell fate, and is commonly deregulated in cancer. Sphingosine 1-phosphate is a signaling molecule with anti-apoptotic, pro-proliferative and pro-angiogenic effects, while conversely, ceramide and sphingosine are pro-apoptotic. The sphingosine kinases (SKs) are key regulators of this sphingolipid rheostat, and are attractive targets for anti-cancer therapy. Here we report a first-in-class ATP-binding site-directed small molecule SK inhibitor, MP-A08, discovered using an approach of structural homology modelling of the ATP-binding site of SK1 and in silico docking with small molecule libraries. MP-A08 is a highly selective ATP competitive SK inhibitor that targets both SK1 and SK2. MP-A08 blocks pro-proliferative signalling pathways, induces mitochondrial-associated apoptosis in a SK-dependent manner, and reduces the growth of human lung adenocarcinoma tumours in a mouse xenograft model by both inducing tumour cell apoptosis and inhibiting tumour angiogenesis. Thus, this selective ATP competitive SK inhibitor provides a promising candidate for potential development as an anti-cancer therapy, and also, due to its different mode of inhibition to other known SK inhibitors, both validates the SKs as targets for anti-cancer therapy, and represents an important experimental tool to study these enzymes. PMID:25788259

  12. Discovery and Optimization of Sulfonyl Acrylonitriles as Selective, Covalent Inhibitors of Protein Phosphatase Methylesterase-1

    PubMed Central

    Bachovchin, Daniel A.; Zuhl, Andrea M.; Speers, Anna E.; Wolfe, Monique R.; Weerapana, Eranthie; Brown, Steven J.; Rosen, Hugh; Cravatt, Benjamin F.

    2011-01-01

    The serine hydrolase protein phosphatase methylesterase-1 (PME-1) regulates the methylesterification state of protein phosphatase 2A (PP2A) and has been implicated in cancer and Alzheimer's disease. We recently reported a fluorescence polarization-activity-based protein profiling (fluopol-ABPP) high-throughput screen for PME-1 that uncovered a remarkably potent and selective class of aza-β-lactam (ABL) PME-1 inhibitors. Here, we describe a distinct set of sulfonyl acrylonitrile inhibitors that also emerged from this screen. The optimized compound, 28 (AMZ30), selectively inactivates PME-1 and reduces the demethylated form of PP2A in living cells. Considering that 28 is structurally unrelated to ABL inhibitors of PME-1, these agents, together, provide a valuable set of pharmacological probes to study the role of methylation in regulating PP2A function. We furthermore observed that several serine hydrolases were sensitive to analogs of 28, suggesting that more extensive structural exploration of the sulfonyl acrylonitrile chemotype may result in useful inhibitors for other members of this large enzyme class. PMID:21639134

  13. Molecular docking and enzymatic evaluation to identify selective inhibitors of aspartate semialdehyde dehydrogenase

    PubMed Central

    Luniwal, Amarjit; Wang, Lin; Pavlovsky, Alexander; Erhardt, Paul W.; Viola, Ronald E.

    2013-01-01

    Microbes that have gained resistance against antibiotics pose a major emerging threat to human health. New targets must be identified that will guide the development of new classes of antibiotics. The selective inhibition of key microbial enzymes that are responsible for the biosynthesis of essential metabolites can be an effective way to counter this growing threat. Aspartate semialdehyde dehydrogenases (ASADHs) produce an early branch point metabolite in a microbial biosynthetic pathway for essential amino acids and for quorum sensing molecules. In this study, molecular modeling and docking studies were performed to achieve two key objectives that are important for the identification of new selective inhibitors of ASADH. First, virtual screening of a small library of compounds was used to identify new core structures that could serve as potential inhibitors of the ASADHs. Compounds have been identified from diverse chemical classes that are predicted to bind to ASADH with high affinity. Next, molecular docking studies were used to prioritize analogs within each class for synthesis and testing against representative bacterial forms of ASADH from Streptococcus pneumoniae and Vibrio cholerae. These studies have led to new micromolar inhibitors of ASADH, demonstrating the utility of this molecular modeling and docking approach for the identification of new classes of potential enzyme inhibitors. PMID:22464683

  14. Molecular docking and enzymatic evaluation to identify selective inhibitors of aspartate semialdehyde dehydrogenase.

    PubMed

    Luniwal, Amarjit; Wang, Lin; Pavlovsky, Alexander; Erhardt, Paul W; Viola, Ronald E

    2012-05-01

    Microbes that have gained resistance against antibiotics pose a major emerging threat to human health. New targets must be identified that will guide the development of new classes of antibiotics. The selective inhibition of key microbial enzymes that are responsible for the biosynthesis of essential metabolites can be an effective way to counter this growing threat. Aspartate semialdehyde dehydrogenases (ASADHs) produce an early branch point metabolite in a microbial biosynthetic pathway for essential amino acids and for quorum sensing molecules. In this study, molecular modeling and docking studies were performed to achieve two key objectives that are important for the identification of new selective inhibitors of ASADH. First, virtual screening of a small library of compounds was used to identify new core structures that could serve as potential inhibitors of the ASADHs. Compounds have been identified from diverse chemical classes that are predicted to bind to ASADH with high affinity. Next, molecular docking studies were used to prioritize analogs within each class for synthesis and testing against representative bacterial forms of ASADH from Streptococcus pneumoniae and Vibrio cholerae. These studies have led to new micromolar inhibitors of ASADH, demonstrating the utility of this molecular modeling and docking approach for the identification of new classes of potential enzyme inhibitors. PMID:22464683

  15. New selective carbonic anhydrase IX inhibitors: synthesis and pharmacological evaluation of diarylpyrazole-benzenesulfonamides.

    PubMed

    Rogez-Florent, Tiphaine; Meignan, Samuel; Foulon, Catherine; Six, Perrine; Gros, Abigaëlle; Bal-Mahieu, Christine; Supuran, Claudiu T; Scozzafava, Andrea; Frédérick, Raphaël; Masereel, Bernard; Depreux, Patrick; Lansiaux, Amélie; Goossens, Jean-François; Gluszok, Sébastien; Goossens, Laurence

    2013-03-15

    Carbonic anhydrase (CA) IX expression is increased upon hypoxia and has been proposed as a therapeutic target since it has been associated with poor prognosis, tumor progression and pH regulation. We report the synthesis and the pharmacological evaluation of a new class of human carbonic anhydrase (hCA) inhibitors, 4-(5-aryl-2-hydroxymethyl-pyrazol-1-yl)-benzenesulfonamides. A molecular modeling study was conducted in order to simulate the binding mode of this new family of enzyme inhibitors within the active site of hCA IX. Pharmacological studies revealed high hCA IX inhibitory potency in the parameters nanomolar range. This study showed that the position of sulfonamide group in meta of the 1-phenylpyrazole increase a selectivity hCA IX versus hCA II of our compounds. An in vitro antiproliferative screening has been performed on the breast cancer MDA-MB-231 cell using doxorubicin as cytotoxic agent and in presence of selected CA IX inhibitor. The results shown that the cytotoxic efficiency of doxorubicin in an hypoxic environment, expressed in IC50 value, is restored at 20% level with 1μM CA IX inhibitor. PMID:23168081

  16. Selection of orlistat as a potential inhibitor for lipase from Candida species

    PubMed Central

    Khedidja, Benarous; Abderrahman, Linani

    2011-01-01

    Infections caused by Candida species manifest in a number of diseases, including candidemia, vulvovaginal candidiasis, endocarditis, and peritonitis. Candida species have been reported to possess lipolytic activity due to the secretion of lipolytic enzymes such as esterases, lipases and phospholipases. Extra-cellular hydrolytic enzymes seem to play an important role in Candida overgrowth. Candidiasis is commonly treated with antimycotics such as clotrimazole and nystatin. The antimycotics bind to a major component of the fungal cell membrane (ergosterol), forming pores that lead to death of the fungus. However, the secondary effects caused during such treatment have aroused a need to develop a treatment based on lipase inhibition. Nonetheless, no such lipase inhibitors for candidiasis treatment are currently available. Thus, we have performed a docking study with the natural inhibitor, orlistat or tetrahydrolipstatin. Our results have shown ten possible binding inhibitors to Candida rugosa lipase (CRL), out of which one possibility was selected, based on the weakest interatomic distance of 2.7 Å. Therefore, we propose the selection and design of a potential inhibitor candidate, orlistat for the treatment of candidiasis infections. However, this study has to be supported with in vitro and in vivo experiments to demonstrate the effectiveness of orlistat in lipase inhibition. PMID:22125382

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

    PubMed Central

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

    2015-01-01

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

  18. Discovery of Selective Small Molecule ROMK Inhibitors as Potential New Mechanism Diuretics.

    PubMed

    Tang, Haifeng; Walsh, Shawn P; Yan, Yan; de Jesus, Reynalda K; Shahripour, Aurash; Teumelsan, Nardos; Zhu, Yuping; Ha, Sookhee; Owens, Karen A; Thomas-Fowlkes, Brande S; Felix, John P; Liu, Jessica; Kohler, Martin; Priest, Birgit T; Bailey, Timothy; Brochu, Richard; Alonso-Galicia, Magdalena; Kaczorowski, Gregory J; Roy, Sophie; Yang, Lihu; Mills, Sander G; Garcia, Maria L; Pasternak, Alexander

    2012-05-10

    The renal outer medullary potassium channel (ROMK or Kir1.1) is a putative drug target for a novel class of diuretics that could be used for the treatment of hypertension and edematous states such as heart failure. An internal high-throughput screening campaign identified 1,4-bis(4-nitrophenethyl)piperazine (5) as a potent ROMK inhibitor. It is worth noting that this compound was identified as a minor impurity in a screening hit that was responsible for all of the initially observed ROMK activity. Structure-activity studies resulted in analogues with improved rat pharmacokinetic properties and selectivity over the hERG channel, providing tool compounds that can be used for in vivo pharmacological assessment. The featured ROMK inhibitors were also selective against other members of the inward rectifier family of potassium channels. PMID:24900480

  19. Isosorbide-2-benzyl carbamate-5-salicylate, a peripheral anionic site binding subnanomolar selective butyrylcholinesterase inhibitor.

    PubMed

    Carolan, Ciaran G; Dillon, Gerald P; Khan, Denise; Ryder, Sheila A; Gaynor, Joanne M; Reidy, Sean; Marquez, Juan F; Jones, Mike; Holland, Valerie; Gilmer, John F

    2010-02-11

    Isosorbide-2-benzyl carbamate-5-benzoate is a highly potent and selective BuChE inhibitor. Meanwhile, isosorbide-2-aspirinate-5-salicylate is a highly effective aspirin prodrug that relies on the salicylate portion to interact productively with human BuChE. By integrating the salicylate group into the carbamate design, we have produced isosorbide-2-benzyl carbamate-5-salicylate, an inhibitor of high potency (150 pM) and selectivity for human BuChE over AChE (666000) and CES2 (23000). Modeling and mutant studies indicate that it achieves its exceptional potency because of an interaction with the polar D70/Y332 cluster in the PAS of BuChE in addition to pseudosubstrate interactions with the active site. PMID:20067290

  20. Discovery of potent and selective CDK8 inhibitors from an HSP90 pharmacophore.

    PubMed

    Schiemann, Kai; Mallinger, Aurélie; Wienke, Dirk; Esdar, Christina; Poeschke, Oliver; Busch, Michael; Rohdich, Felix; Eccles, Suzanne A; Schneider, Richard; Raynaud, Florence I; Czodrowski, Paul; Musil, Djordje; Schwarz, Daniel; Urbahns, Klaus; Blagg, Julian

    2016-03-01

    Here we describe the discovery and optimization of 3-benzylindazoles as potent and selective inhibitors of CDK8, also modulating CDK19, discovered from a high-throughput screening (HTS) campaign sampling the Merck compound collection. The primary hits with strong HSP90 affinity were subsequently optimized to potent and selective CDK8 inhibitors which demonstrate inhibition of WNT pathway activity in cell-based assays. X-ray crystallographic data demonstrated that 3-benzylindazoles occupy the ATP binding site of CDK8 and adopt a Type I binding mode. Medicinal chemistry optimization successfully led to improved potency, physicochemical properties and oral pharmacokinetics. Modulation of phospho-STAT1, a pharmacodynamic biomarker of CDK8, was demonstrated in an APC-mutant SW620 human colorectal carcinoma xenograft model following oral administration. PMID:26852363

  1. Synthesis of a series of unsaturated ketone derivatives as selective and reversible monoamine oxidase inhibitors.

    PubMed

    Choi, Ji Won; Jang, Bo Ko; Cho, Nam-chul; Park, Jong-Hyun; Yeon, Seul Ki; Ju, Eun Ji; Lee, Yong Sup; Han, Gyoonhee; Pae, Ae Nim; Kim, Dong Jin; Park, Ki Duk

    2015-10-01

    We have synthesized three categories of α,β-unsaturated carbonyl derivatives and evaluated their MAO-A and MAO-B inhibitory activities. Among them, compound 10b including α,β-unsaturated ketone group showed the most potent and selective MAO-B inhibitory activity (IC₅₀ human MAO-B 16 nM, >6000-fold selective vs MAO-A) and compound 10b exhibited good reversibility compared with selegiline, a well-known irreversible MAO-B inhibitor. However, both α,β-unsaturated amide and ester derivatives exhibited weaker MAO-B inhibition potencies. The docking studies provided insights into the possible binding modes and the key interaction sites of the synthesized MAO-B inhibitors. PMID:26337020

  2. N-Substituted acetamidines and 2-methylimidazole derivatives as selective inhibitors of neuronal nitric oxide synthase.

    PubMed

    Maccallini, Cristina; Patruno, Antonia; Lannutti, Fabio; Ammazzalorso, Alessandra; De Filippis, Barbara; Fantacuzzi, Marialuigia; Franceschelli, Sara; Giampietro, Letizia; Masella, Simona; Felaco, Mario; Re, Nazzareno; Amoroso, Rosa

    2010-11-15

    A series of N-substituted acetamidines and 2-methylimidazole derivatives structurally related to W1400 were synthesized and evaluated as Nitric Oxide Synthase (NOS) inhibitors. Analogs with sterically hindering isopropyl and phenyl substituents on the benzylic carbon connecting the aromatic core of W1400 to the acetamidine nitrogen, showed good inhibitory potency for nNOS (IC(50)=0.2 and 0.3 μM) and selectivity over eNOS (500 and 1166) and to a lesser extent over iNOS (50 and 100). A molecular modeling study allowed to shed light on the effects of the structural modifications on the selectivity of the designed inhibitors toward the different NOS isoforms. PMID:20933416

  3. Novel ribofuranosylnucleoside lead compounds for potent and selective inhibitors of mitochondrial thymidine kinase-2.

    PubMed Central

    Balzarini, J; Zhu, C; De Clercq , E; Pérez-Pérez, M J; Chamorro, C; Camarasa, M J; Karlsson, A

    2000-01-01

    The ribonucleoside analogues (E)-5-(2-bromovinyl)uridine (5-BV-Urd) and 3'-spiro-(4'-amino-1',2'-oxathiole-2',2'-dioxide)-5-methyluridine (3'-AOD-5-MeUrd) emerged as potent and selective competitive inhibitors of mitochondrial thymidine kinase (TK)-2 with respect to thymidine (K(i)/K(m) values of 9.0 and 1.2 respectively). Cytosolic TK-1 did not show measurable affinity for these compounds. [(32)P]Phosphate transfer studies from [gamma-(32)P]ATP to 5-BV-Urd and 3'-AOD-5-MeUrd revealed extremely poor substrate activity but potent inhibitory potential of the compounds. It was concluded that the ribonucleosides 5-BV-Urd and 3'-AOD-5-MeUrd represent two new lead compounds for potent and selective inhibitors of mitochondrial TK-2. PMID:10998359

  4. Selectivity Profiling and Biological Activity of Novel β-Carbolines as Potent and Selective DYRK1 Kinase Inhibitors

    PubMed Central

    Rüben, Katharina; Wurzlbauer, Anne; Walte, Agnes; Sippl, Wolfgang; Bracher, Franz; Becker, Walter

    2015-01-01

    DYRK1A is a pleiotropic protein kinase with diverse functions in cellular regulation, including cell cycle control, neuronal differentiation, and synaptic transmission. Enhanced activity and overexpression of DYRK1A have been linked to altered brain development and function in Down syndrome and neurodegenerative diseases such as Alzheimer’s disease. The β-carboline alkaloid harmine is a high affinity inhibitor of DYRK1A but suffers from the drawback of inhibiting monoamine oxidase A (MAO-A) with even higher potency. Here we characterized a series of novel harmine analogs with minimal or absent MAO-A inhibitory activity. We identified several inhibitors with submicromolar potencies for DYRK1A and selectivity for DYRK1A and DYRK1B over the related kinases DYRK2 and HIPK2. An optimized inhibitor, AnnH75, inhibited CLK1, CLK4, and haspin/GSG2 as the only off-targets in a panel of 300 protein kinases. In cellular assays, AnnH75 dose-dependently reduced the phosphorylation of three known DYRK1A substrates (SF3B1, SEPT4, and tau) without negative effects on cell viability. AnnH75 inhibited the cotranslational tyrosine autophosphorylation of DYRK1A and threonine phosphorylation of an exogenous substrate protein with similar potency. In conclusion, we have characterized an optimized β-carboline inhibitor as a highly selective chemical probe that complies with desirable properties of drug-like molecules and is suitable to interrogate the function of DYRK1A in biological studies. PMID:26192590

  5. Selectivity Profiling and Biological Activity of Novel β-Carbolines as Potent and Selective DYRK1 Kinase Inhibitors.

    PubMed

    Rüben, Katharina; Wurzlbauer, Anne; Walte, Agnes; Sippl, Wolfgang; Bracher, Franz; Becker, Walter

    2015-01-01

    DYRK1A is a pleiotropic protein kinase with diverse functions in cellular regulation, including cell cycle control, neuronal differentiation, and synaptic transmission. Enhanced activity and overexpression of DYRK1A have been linked to altered brain development and function in Down syndrome and neurodegenerative diseases such as Alzheimer's disease. The β-carboline alkaloid harmine is a high affinity inhibitor of DYRK1A but suffers from the drawback of inhibiting monoamine oxidase A (MAO-A) with even higher potency. Here we characterized a series of novel harmine analogs with minimal or absent MAO-A inhibitory activity. We identified several inhibitors with submicromolar potencies for DYRK1A and selectivity for DYRK1A and DYRK1B over the related kinases DYRK2 and HIPK2. An optimized inhibitor, AnnH75, inhibited CLK1, CLK4, and haspin/GSG2 as the only off-targets in a panel of 300 protein kinases. In cellular assays, AnnH75 dose-dependently reduced the phosphorylation of three known DYRK1A substrates (SF3B1, SEPT4, and tau) without negative effects on cell viability. AnnH75 inhibited the cotranslational tyrosine autophosphorylation of DYRK1A and threonine phosphorylation of an exogenous substrate protein with similar potency. In conclusion, we have characterized an optimized β-carboline inhibitor as a highly selective chemical probe that complies with desirable properties of drug-like molecules and is suitable to interrogate the function of DYRK1A in biological studies. PMID:26192590

  6. Structural basis for the design of selective phosphodiesterase 4B inhibitors.

    PubMed

    Fox, David; Burgin, Alex B; Gurney, Mark E

    2014-03-01

    Phosphodiesterase-4B (PDE4B) regulates the pro-inflammatory Toll Receptor -Tumor Necrosis Factor α (TNFα) pathway in monocytes, macrophages and microglial cells. As such, it is an important, although under-exploited molecular target for anti-inflammatory drugs. This is due in part to the difficulty of developing selective PDE4B inhibitors as the amino acid sequence of the PDE4 active site is identical in all PDE4 subtypes (PDE4A-D). We show that highly selective PDE4B inhibitors can be designed by exploiting sequence differences outside the active site. Specifically, PDE4B selectivity can be achieved by capture of a C-terminal regulatory helix, now termed CR3 (Control Region 3), across the active site in a conformation that closes access by cAMP. PDE4B selectivity is driven by a single amino acid polymorphism in CR3 (Leu674 in PDE4B1 versus Gln594 in PDE4D). The reciprocal mutations in PDE4B and PDE4D cause a 70-80 fold shift in selectivity. Our structural studies show that CR3 is flexible and can adopt multiple orientations and multiple registries in the closed conformation. The new co-crystal structure with bound ligand provides a guide map for the design of PDE4B selective anti-inflammatory drugs. PMID:24361374

  7. Discovery of Subtype Selective Janus Kinase (JAK) Inhibitors by Structure-Based Virtual Screening.

    PubMed

    Bajusz, Dávid; Ferenczy, György G; Keserű, György M

    2016-01-25

    Janus kinase inhibitors represent a promising opportunity for the pharmaceutical intervention of various inflammatory and oncological indications. Subtype selective inhibition of these enzymes, however, is still a very challenging goal. In this study, a novel, customized virtual screening protocol was developed with the intention of providing an efficient tool for the discovery of subtype selective JAK2 inhibitors. The screening protocol involves protein ensemble-based docking calculations combined with an Interaction Fingerprint (IFP) based scoring scheme for estimating ligand affinities and selectivities, respectively. The methodology was validated in retrospective studies and was applied prospectively to screen a large database of commercially available compounds. Six compounds were identified and confirmed in vitro, with an indazole-based hit exhibiting promising selectivity for JAK2 vs JAK1. Having demonstrated that the described methodology is capable of identifying subtype selective chemical starting points with a favorable hit rate (11%), we believe that the presented screening concept can be useful for other kinase targets with challenging selectivity profiles. PMID:26682735

  8. MLN8054 and Alisertib (MLN8237): Discovery of Selective Oral Aurora A Inhibitors

    PubMed Central

    2015-01-01

    The Aurora kinases are essential for cell mitosis, and the dysregulation of Aurora A and B have been linked to the etiology of human cancers. Investigational agents MLN8054 (8) and alisertib (MLN8237, 10) have been identified as high affinity, selective, orally bioavailable inhibitors of Aurora A that have advanced into human clinical trials. Alisertib (10) is currently being evaluated in multiple Phase II and III clinical trials in hematological malignancies and solid tumors. PMID:26101564

  9. MLN8054 and Alisertib (MLN8237): Discovery of Selective Oral Aurora A Inhibitors.

    PubMed

    Sells, Todd B; Chau, Ryan; Ecsedy, Jeffrey A; Gershman, Rachel E; Hoar, Kara; Huck, Jessica; Janowick, David A; Kadambi, Vivek J; LeRoy, Patrick J; Stirling, Matthew; Stroud, Stephen G; Vos, Tricia J; Weatherhead, Gabriel S; Wysong, Deborah R; Zhang, Mengkun; Balani, Suresh K; Bolen, Joseph B; Manfredi, Mark G; Claiborne, Christopher F

    2015-06-11

    The Aurora kinases are essential for cell mitosis, and the dysregulation of Aurora A and B have been linked to the etiology of human cancers. Investigational agents MLN8054 (8) and alisertib (MLN8237, 10) have been identified as high affinity, selective, orally bioavailable inhibitors of Aurora A that have advanced into human clinical trials. Alisertib (10) is currently being evaluated in multiple Phase II and III clinical trials in hematological malignancies and solid tumors. PMID:26101564

  10. Kinetic and structural studies of phosphodiesterase-8A and implication on the inhibitor selectivity

    PubMed Central

    Wang, Huanchen; Yan, Zier; Yang, Serena; Cai, Jiwen; Robinson, Howard; Ke, Hengming

    2009-01-01

    Cyclic nucleotide phosphodiesterase-8 (PDE8) is a family of cAMP-specific enzymes and plays important roles in many biological processes, including T-cell activation, testosterone production, adrenocortical hyperplasia, and thyroid function. However, no PDE8 selective inhibitors are available for trial treatment of human diseases. Here we report kinetic properties of the highly active PDE8A1 catalytic domain prepared from refolding and its crystal structures in the unliganded and 3-isobutyl-1-methylxanthine (IBMX) bound forms at 1.9 and 2.1 Å resolutions, respectively. The PDE8A1 catalytic domain has KM of 1.8 μM, Vmax of 6.1 μmol/min/mg, kcat of 4.0 s−1 for cAMP, and KM of 1.6 mM, Vmax of 2.5 μmol/min/mg, kcat of 1.6 s−1 for cGMP, thus indicating that the substrate specificity of PDE8 is dominated by KM. The structure of the PDE8A1 catalytic domain has similar topology as those of other PDE families, but contains two extra helices around Asn685-Thr710. Since this fragment is distant from the active site of the enzyme, its impact on the catalysis is unclear. The PDE8A1 catalytic domain is insensitive to the IBMX inhibition (IC50 = 700 μM). The unfavorable interaction of IBMX in the PDE8A1-IBMX structure suggests an important role of Tyr748 in the inhibitor binding. Indeed, the mutation of Tyr748 to phenylalanine increases the PDE8A1 sensitivity to several non-selective or family-selective PDE inhibitors. Thus, the structural and mutagenesis studies provide not only insight into the enzymatic properties, but also guidelines for design of PDE8 selective inhibitors. PMID:18983167

  11. Selectivity by Small-Molecule Inhibitors of Protein Interactions Can Be Driven by Protein Surface Fluctuations

    PubMed Central

    Johnson, David K.; Karanicolas, John

    2015-01-01

    Small-molecules that inhibit interactions between specific pairs of proteins have long represented a promising avenue for therapeutic intervention in a variety of settings. Structural studies have shown that in many cases, the inhibitor-bound protein adopts a conformation that is distinct from its unbound and its protein-bound conformations. This plasticity of the protein surface presents a major challenge in predicting which members of a protein family will be inhibited by a given ligand. Here, we use biased simulations of Bcl-2-family proteins to generate ensembles of low-energy conformations that contain surface pockets suitable for small molecule binding. We find that the resulting conformational ensembles include surface pockets that mimic those observed in inhibitor-bound crystal structures. Next, we find that the ensembles generated using different members of this protein family are overlapping but distinct, and that the activity of a given compound against a particular family member (ligand selectivity) can be predicted from whether the corresponding ensemble samples a complementary surface pocket. Finally, we find that each ensemble includes certain surface pockets that are not shared by any other family member: while no inhibitors have yet been identified to take advantage of these pockets, we expect that chemical scaffolds complementing these “distinct” pockets will prove highly selective for their targets. The opportunity to achieve target selectivity within a protein family by exploiting differences in surface fluctuations represents a new paradigm that may facilitate design of family-selective small-molecule inhibitors of protein-protein interactions. PMID:25706586

  12. Design of novel quinazoline derivatives and related analogues as potent and selective ALK5 inhibitors

    SciTech Connect

    Gellibert, F.; Fouchet, M.-H.; Nguyen, V.-L.; Wang, R.; Krysa, G.; de Gouville, A.-C.; Huet, S.; Dodic, N.

    2009-07-23

    Starting from quinazoline 3a, we designed potent and selective ALK5 inhibitors over p38MAP kinase from a rational drug design approach based on co-crystal structures in the human ALK5 kinase domain. The quinazoline 3d exhibited also in vivo activity in an acute rat model of DMN-induced liver fibrosis when administered orally at 5 mg/kg (bid).

  13. Optimization of tetrahydronaphthalene inhibitors of Raf with selectivity over hERG.

    PubMed

    Huang, Shih-Chung; Adhikari, Sharmila; Afroze, Roushan; Brewer, Katherine; Calderwood, Emily F; Chouitar, Jouhara; England, Dylan B; Fisher, Craig; Galvin, Katherine M; Gaulin, Jeffery; Greenspan, Paul D; Harrison, Sean J; Kim, Mi-Sook; Langston, Steven P; Ma, Li-Ting; Menon, Saurabh; Mizutani, Hirotake; Rezaei, Mansoureh; Smith, Michael D; Zhang, Dong Mei; Gould, Alexandra E

    2016-02-15

    Investigations of a biaryl ether scaffold identified tetrahydronaphthalene Raf inhibitors with good in vivo activity; however these compounds had affinity toward the hERG potassium channel. Herein we describe our work to eliminate this hERG activity via alteration of the substituents on the benzoic amide functionality. The resulting compounds have improved selectivity against the hERG channel, good pharmacokinetic properties and potently inhibit the Raf pathway in vivo. PMID:26804230

  14. Amotivational syndrome associated with selective serotonin reuptake inhibitors in children and adolescents.

    PubMed

    Garland, E J; Baerg, E A

    2001-01-01

    A frontal lobe syndrome has previously been reported in adults treated with selective serotonin reuptake inhibitors (SSRIs), but not in children. Five typical cases of apathy and lack of motivation, one accompanied by disinhibition, are described in a child and four adolescents. Symptoms were dose related and reversible. The subtlety of symptoms, lack of insight in patients, disabling effects, and delayed onset indicate a need for clinicians to inform families of these potential symptoms when SSRIs are prescribed. PMID:11436958

  15. Discovery of a Highly Selective JAK2 Inhibitor, BMS-911543, for the Treatment of Myeloproliferative Neoplasms

    PubMed Central

    2015-01-01

    JAK2 kinase inhibitors are a promising new class of agents for the treatment of myeloproliferative neoplasms and have potential for the treatment of other diseases possessing a deregulated JAK2-STAT pathway. X-ray structure and ADME guided refinement of C-4 heterocycles to address metabolic liability present in dialkylthiazole 1 led to the discovery of a clinical candidate, BMS-911543 (11), with excellent kinome selectivity, in vivo PD activity, and safety profile. PMID:26288683

  16. Bis-Aryl Urea Derivatives as Potent and Selective LIM Kinase (Limk) Inhibitors

    PubMed Central

    Yin, Yan; Zheng, Ke; Eid, Nibal; Howard, Shannon; Jeong, Ji-Hak; Yi, Fei; Guo, Jia; Park, Chul M; Bibian, Mathieu; Wu, Weilin; Hernandez, Pamela; Park, HaJeung; Wu, Yuntao; Luo, Jun-Li; LoGrasso, Philip V.; Feng, Yangbo

    2015-01-01

    The discovery/optimization of bis-aryl ureas as Limk inhibitors to obtain high potency and selectivity, and appropriate pharmacokinetic properties through systematic SAR studies is reported. Docking studies supported the observed SAR. Optimized Limk inhibitors had high biochemical potency (IC50 < 25 nM), excellent selectivity against ROCK and JNK kinases (> 400-fold), potent inhibition of cofilin phosphorylation in A7r5,PC-3, and CEM-SS T cells (IC50 < 1 μM), and good in vitro and in vivo pharmacokinetic properties. In the profiling against a panel of 61 kinases, compound 18b at 1 μM inhibited only Limk1 and STK16 with ≥ 80% inhibition. Compounds 18b and 18f were highly efficient in inhibiting cell-invasion/migration in PC-3 cells. In addition, compound 18w was demonstrated to be effective on reducing intraocular pressure (IOP) on rat eyes. Taken together, these data demonstrated that we had developed a novel class of bis-aryl urea derived potent and selective Limk inhibitors. PMID:25621531

  17. Pyogenic granuloma in patients treated with selective BRAF inhibitors: another manifestation of paradoxical pathway activation.

    PubMed

    Henning, Benjamin; Stieger, Pascale; Kamarachev, Jivko; Dummer, Reinhard; Goldinger, Simone M

    2016-06-01

    Cutaneous toxicities under therapy with selective BRAF inhibitors such as vemurafenib or encorafenib (LGX818) are frequent, including plantar hyperkeratosis, squamous cell carcinoma, and second primary melanoma. Pyogenic granuloma is a benign, rapidly growing, eruptive hemangioma that often bleeds and ulcerates. Common causes are mechanical trauma and cast immobilization, as well as multiple drugs such as retinoids and antineoplastic agents. However, the development of pyogenic granuloma under treatment with encorafenib (LGX818) has not yet been reported. These three cases might be further examples for paradoxical activation of the mitogen-activated protein kinase pathway. We report three male patients with metastatic BRAFV600E-mutated melanoma who developed pyogenic granulomas 16, 10, and 12 weeks after treatment initiation with the selective BRAF inhibitors vemurafenib or encorafenib (LGX818). Except for one patient receiving retinoids, the clinical history for other frequent causes of pyogenic granuloma was negative. Pyogenic granulomas are not listed in the drugs investigator brochure but seem to be associated with selective BRAF inhibitors and might be a cutaneous phenomenon of paradoxical mitogen-activated protein kinase pathway activation. This correlation has to be confirmed by further observations. PMID:27116335

  18. Discovery of Potent and Selective Inhibitors of Human Reticulocyte 15- Lipoxygenase-1

    PubMed Central

    Rai, Ganesha; Kenyon, Victor; Jadhav, Ajit; Schultz, Lena; Armstrong, Michelle; Jameson, J Brian; Hoobler, Eric; Leister, William; Simeonov, Anton; Holman, Theodore R.; Maloney, David J.

    2010-01-01

    There are a variety of lipoxygenases in the human body (hLO), each having a distinct role in cellular biology. Human reticulocyte 15-Lipoxygenase-1 (15-hLO-1), which catalyzes the dioxygenation of 1,4-cis,cis-pentadiene-containing polyunsaturated fatty acids, is implicated in a number of diseases including cancer, atherosclerosis, and neurodegenerative conditions. Despite the potential therapeutic relevance of this target, few inhibitors have been reported that are both potent and selective. To this end, we have employed a quantitative high-throughput (qHTS) screen against ~74,000 small molecules in search of reticulocyte 15-hLO-1 selective inhibitors. This screen led to the discovery of a novel chemotype for 15-hLO-1 inhibition, which displays nM potency and is >7,500-fold selective against the related isozymes, 5-hLO, platelet 12-hLO, epithelial 15-hLO-2, ovine cyclooxygenase-1 and human cyclooxygenase-2. In addition, kinetic experiments were performed which indicate that this class of inhibitor is tight binding, reversible, and appears not to reduce the active-site ferric ion. PMID:20866075

  19. Identification of a New Selective Chemical Inhibitor of Mutant Isocitrate Dehydrogenase-1

    PubMed Central

    Kim, Hyo-Joon; Choi, Bu Young; Keum, Young-Sam

    2015-01-01

    Background: Recent genome-wide sequencing studies have identified unexpected genetic alterations in cancer. In particular, missense mutations in isocitrate dehydrogenase-1 (IDH1) at arginine 132, mostly substituted into histidine (IDH1-R132H) were observed to frequently occur in glioma patients. Methods: We have purified recombinant IDH1 and IDH1-R132H proteins and monitored their catalytic activities. In parallel experiments, we have attempted to find new selective IDH1-R132H chemical inhibitor(s) from a fragment-based chemical library. Results: We have found that IDH1, but not IDH1-R132H, can catalyze the conversion of isocitrate into α-ketoglutarate (α-KG). In addition, we have observed that IDH1-R132H was more efficient than IDH1 in converting α-KG into (R)-2-hydroxyglutarate (R-2HG). Moreover, we have identified a new hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective IDH1-R132H inhibitor. Conclusions: We have observed an underlying biochemical mechanism explaining how a heterozygous IDH1 mutation contributes to the generation of R-2HG and increases cellular histone H3 trimethylation levels. We have also identified a novel selective IDH1-R132H chemical hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one, which could be used for a future lead development against IDH1-R132H. PMID:25853107

  20. A potent and selective inhibitor for the UBLCP1 proteasome phosphatase

    PubMed Central

    He, Yantao; Guo, Xing; Yu, Zhi-Hong; Wu, Li; Gunawan, Andrea M.; Zhang, Yan; Dixon, Jack E.; Zhang, Zhong-Yin

    2015-01-01

    The ubiquitin-like domain-containing C-terminal domain phosphatase 1 (UBLCP1) has been implicated as a negative regulator of the proteasome, a key mediator in the ubiquitin-dependent protein degradation. Small molecule inhibitors that block UBLCP1 activity would be valuable as research tools and potential therapeutics for human diseases caused by the cellular accumulation of misfold/damaged proteins. We report a salicylic acid fragment-based library approach aimed at targeting both the phosphatase active site and its adjacent binding pocket for enhanced affinity and selectivity. Screening of the focused libraries led to the identification of the first potent and selective UBLCP1 inhibitor 13. Compound 13 exhibits an IC50 of 1.0 μM for UBLCP1 and greater than 5-fold selectivity against a large panel of protein phosphatases from several distinct families. Importantly, the inhibitor possesses efficacious cellular activity and is capable of inhibiting UBLCP1 function in cells, which in turn up-regulates nuclear proteasome activity. These studies set the groundwork for further developing compound 13 into chemical probes or potential therapeutic agents targeting the UBLCP1 phosphatase. PMID:25907364

  1. Evaluating the binding selectivity of transthyretin amyloid fibril inhibitors in blood plasma

    PubMed Central

    Purkey, Hans E.; Dorrell, Michael I.; Kelly, Jeffery W.

    2001-01-01

    Transthyretin (TTR) tetramer dissociation and misfolding facilitate assembly into amyloid fibrils that putatively cause senile systemic amyloidosis and familial amyloid polyneuropathy. We have previously discovered more than 50 small molecules that bind to and stabilize tetrameric TTR, inhibiting amyloid fibril formation in vitro. A method is presented here to evaluate the binding selectivity of these inhibitors to TTR in human plasma, a complex biological fluid composed of more than 60 proteins and numerous small molecules. Our immunoprecipitation approach isolates TTR and bound small molecules from a biological fluid such as plasma, and quantifies the amount of small molecules bound to the protein by HPLC analysis. This approach demonstrates that only a small subset of the inhibitors that saturate the TTR binding sites in vitro do so in plasma. These selective inhibitors can now be tested in animal models of TTR amyloid disease to probe the validity of the amyloid hypothesis. This method could be easily extended to evaluate small molecule binding selectivity to any protein in a given biological fluid without the necessity of determining or guessing which other protein components may be competitors. This is a central issue to understanding the distribution, metabolism, activity, and toxicity of potential drugs. PMID:11344299

  2. Slow Inhibition and Conformation Selective Properties of Extracellular Signal-Regulated Kinase 1 and 2 Inhibitors

    PubMed Central

    Rudolph, Johannes; Xiao, Yao; Pardi, Arthur; Ahn, Natalie G.

    2016-01-01

    The mitogen-activated protein (MAP) kinase pathway is a target for anticancer therapy, validated using inhibitors of B-Raf and MAP kinase kinase (MKK) 1 and 2. Clinical outcomes show a high frequency of acquired resistance in patient tumors, involving upregulation of activity of the MAP kinase, extracellular signal-regulated kinase (ERK) 1 and 2. Thus, inhibitors for ERK1/2 are potentially important for targeted therapeutics against cancer. The structures and potencies of different ERK inhibitors have been published, but their kinetic mechanisms have not been characterized. Here we perform enzyme kinetic studies on six representative ERK inhibitors, with potencies varying from 100 pM to 20 μM. Compounds with significant biological activity (IC50 < 100 nM) that inhibit in the subnanomolar range (Vertex-11e and SCH772984) display slow-onset inhibition and represent the first inhibitors of ERK2 known to demonstrate slow dissociation rate constants (values of 0.2 and 1.1 h−1, respectively). Furthermore, we demonstrate using kinetic competition assays that Vertex-11e binds with differing affinities to ERK2 in its inactive, unphosphorylated and active, phosphorylated forms. Finally, two-dimensional heteronuclear multiple-quantum correlation nuclear magnetic resonance experiments reveal that distinct conformational states are formed in complexes of Vertex-11e with inactive and active ERK2. Importantly, two conformers interconvert in equilibrium in the active ERK2 apoenzyme, but Vertex-11e strongly shifts the equilibrium completely to one conformer. Thus, a high-affinity, slow dissociation inhibitor stabilizes different enzyme conformations depending on the activity state of ERK2 and reveals properties of conformational selection toward the active kinase. PMID:25350931

  3. Combination of vitamin D metabolites with selective inhibitors of vitamin D metabolism.

    PubMed

    Schuster, Inge; Egger, Helmut; Reddy, G Satyanarayana; Vorisek, Georg

    2003-01-01

    1alpha,25(OH)2D3 exerts antiproliferative, differentiating effects on many cell types, including cancer tissues. In most of its target cells, levels of 1alpha,25(OH)2D3 are regulated by local synthesis via CYP27B and metabolism via CYP24. Rapidly induced by vitamin D, CYP24 repeatedly hydroxylates the vitamin D side chain and ultimately terminates hormonal activity. Aiming at increased hormone levels, lifetime and function, numerous vitamin D analogs have been synthesized with structural modifications, which impede oxidation of the vitamin D side chain. Our group followed a different strategy, namely, blocking 1,25(OH)2D3 metabolism with inhibitors of CYP24. As appropriate inhibitors, we exploited compounds termed azoles, which directly bind to the heme iron of the CYPs via an azole nitrogen and to other parts of the substrate site. We synthesized some 400 azoles and tested their potential to selectively inhibit CYP24, but not hormone synthesis by the related CYP27B. Using primary human keratinocyte cultures as the source of CYP24 and CYP27, we discovered some 50 inhibitors of CYP24 with IC50 values in the nanomole range and selectivities up to 60-fold. As the first representative of selective CYP24 inhibitors, VID400 underwent preclinical development. In human keratinocytes, VID400 stabilized levels of endogenously produced 1alpha,25(OH)2D3, and thereby strongly amplified and prolonged expression of CYP24, a surrogate marker of hormonal function. In parallel, antiproliferative activity showed up at 100-fold or more lower concentrations of 1alpha,25(OH)2D3. This data suggests that CYP24 inhibitors could become attractive drugs in antiproliferative therapy, used as single entities to increase or extend endogenous hormone function or in combination with low doses of potent analogs. Moreover, we used selective inhibitors as valuable tools to (a) elucidate regulatory mechanisms of vitamin D synthesis and metabolism, (b) determine intrinsic activities of the otherwise

  4. Converting potent indeno[1,2-b]indole inhibitors of protein kinase CK2 into selective inhibitors of the breast cancer resistance protein ABCG2.

    PubMed

    Jabor Gozzi, Gustavo; Bouaziz, Zouhair; Winter, Evelyn; Daflon-Yunes, Nathalia; Aichele, Dagmar; Nacereddine, Abdelhamid; Marminon, Christelle; Valdameri, Glaucio; Zeinyeh, Waël; Bollacke, Andre; Guillon, Jean; Lacoudre, Aline; Pinaud, Noël; Cadena, Silvia M; Jose, Joachim; Le Borgne, Marc; Di Pietro, Attilio

    2015-01-01

    A series of indeno[1,2-b]indole-9,10-dione derivatives were synthesized as human casein kinase II (CK2) inhibitors. The most potent inhibitors contained a N(5)-isopropyl substituent on the C-ring. The same series of compounds was found to also inhibit the breast cancer resistance protein ABCG2 but with totally different structure-activity relationships: a N(5)-phenethyl substituent was critical, and additional hydrophobic substituents at position 7 or 8 of the D-ring or a methoxy at phenethyl position ortho or meta also contributed to inhibition. The best ABCG2 inhibitors, such as 4c, 4h, 4i, 4j, and 4k, behaved as very weak inhibitors of CK2, whereas the most potent CK2 inhibitors, such as 4a, 4p, and 4e, displayed limited interaction with ABCG2. It was therefore possible to convert, through suitable substitutions of the indeno[1,2-b]indole-9,10-dione scaffold, potent CK2 inhibitors into selective ABCG2 inhibitors and vice versa. In addition, some of the best ABCG2 inhibitors, which displayed a very low cytotoxicity, thus giving a high therapeutic ratio, and appeared not to be transported, constitute promising candidates for further investigations. PMID:25272055

  5. A class of selective antibacterials derived from a protein kinase inhibitor pharmacophore

    PubMed Central

    Miller, J. Richard; Dunham, Steve; Mochalkin, Igor; Banotai, Craig; Bowman, Matthew; Buist, Susan; Dunkle, Bill; Hanna, Debra; Harwood, H. James; Huband, Michael D.; Karnovsky, Alla; Kuhn, Michael; Limberakis, Chris; Liu, Jia Y.; Mehrens, Shawn; Mueller, W. Thomas; Narasimhan, Lakshmi; Ogden, Adam; Ohren, Jeff; Prasad, J. V. N. Vara; Shelly, John A.; Skerlos, Laura; Sulavik, Mark; Thomas, V. Hayden; VanderRoest, Steve; Wang, LiAnn; Wang, Zhigang; Whitton, Amy; Zhu, Tong; Stover, C. Kendall

    2009-01-01

    As the need for novel antibiotic classes to combat bacterial drug resistance increases, the paucity of leads resulting from target-based antibacterial screening of pharmaceutical compound libraries is of major concern. One explanation for this lack of success is that antibacterial screening efforts have not leveraged the eukaryotic bias resulting from more extensive chemistry efforts targeting eukaryotic gene families such as G protein-coupled receptors and protein kinases. Consistent with a focus on antibacterial target space resembling these eukaryotic targets, we used whole-cell screening to identify a series of antibacterial pyridopyrimidines derived from a protein kinase inhibitor pharmacophore. In bacteria, the pyridopyrimidines target the ATP-binding site of biotin carboxylase (BC), which catalyzes the first enzymatic step of fatty acid biosynthesis. These inhibitors are effective in vitro and in vivo against fastidious Gram-negative pathogens including Haemophilus influenzae. Although the BC active site has architectural similarity to those of eukaryotic protein kinases, inhibitor binding to the BC ATP-binding site is distinct from the protein kinase-binding mode, such that the inhibitors are selective for bacterial BC. In summary, we have discovered a promising class of potent antibacterials with a previously undescribed mechanism of action. In consideration of the eukaryotic bias of pharmaceutical libraries, our findings also suggest that pursuit of a novel inhibitor leads for antibacterial targets with active-site structural similarity to known human targets will likely be more fruitful than the traditional focus on unique bacterial target space, particularly when structure-based and computational methodologies are applied to ensure bacterial selectivity. PMID:19164768

  6. A class of selective antibacterials derived from a protein kinase inhibitor pharmacophore

    SciTech Connect

    Miller, J. Richard; Dunham, Steve; Mochalkin, Igor; Banotai, Craig; Bowman, Matthew; Buist, Susan; Dunkle, Bill; Hanna, Debra; Harwood, H. James; Huband, Michael D.; Karnovsky, Alla; Kuhn, Michael; Limberakis, Chris; Liu, Jia Y.; Mehrens, Shawn; Mueller, W. Thomas; Narasimhan, Lakshmi; Ogden, Adam; Ohren, Jeff; Prasad, J.V.N. Vara; Shelly, John A.; Skerlos, Laura; Sulavik, Mark; Thomas, V. Hayden; VanderRoest, Steve; Wang, LiAnn; Wang, Zhigang; Whitton, Amy; Zhu, Tong; Stover, C. Kendall

    2009-06-25

    As the need for novel antibiotic classes to combat bacterial drug resistance increases, the paucity of leads resulting from target-based antibacterial screening of pharmaceutical compound libraries is of major concern. One explanation for this lack of success is that antibacterial screening efforts have not leveraged the eukaryotic bias resulting from more extensive chemistry efforts targeting eukaryotic gene families such as G protein-coupled receptors and protein kinases. Consistent with a focus on antibacterial target space resembling these eukaryotic targets, we used whole-cell screening to identify a series of antibacterial pyridopyrimidines derived from a protein kinase inhibitor pharmacophore. In bacteria, the pyridopyrimidines target the ATP-binding site of biotin carboxylase (BC), which catalyzes the first enzymatic step of fatty acid biosynthesis. These inhibitors are effective in vitro and in vivo against fastidious Gram-negative pathogens including Haemophilus influenzae. Although the BC active site has architectural similarity to those of eukaryotic protein kinases, inhibitor binding to the BC ATP-binding site is distinct from the protein kinase-binding mode, such that the inhibitors are selective for bacterial BC. In summary, we have discovered a promising class of potent antibacterials with a previously undescribed mechanism of action. In consideration of the eukaryotic bias of pharmaceutical libraries, our findings also suggest that pursuit of a novel inhibitor leads for antibacterial targets with active-site structural similarity to known human targets will likely be more fruitful than the traditional focus on unique bacterial target space, particularly when structure-based and computational methodologies are applied to ensure bacterial selectivity.

  7. Parallel medicinal chemistry approaches to selective HDAC1/HDAC2 inhibitor (SHI-1:2) optimization.

    PubMed

    Kattar, Solomon D; Surdi, Laura M; Zabierek, Anna; Methot, Joey L; Middleton, Richard E; Hughes, Bethany; Szewczak, Alexander A; Dahlberg, William K; Kral, Astrid M; Ozerova, Nicole; Fleming, Judith C; Wang, Hongmei; Secrist, Paul; Harsch, Andreas; Hamill, Julie E; Cruz, Jonathan C; Kenific, Candia M; Chenard, Melissa; Miller, Thomas A; Berk, Scott C; Tempest, Paul

    2009-02-15

    The successful application of both solid and solution phase library synthesis, combined with tight integration into the medicinal chemistry effort, resulted in the efficient optimization of a novel structural series of selective HDAC1/HDAC2 inhibitors by the MRL-Boston Parallel Medicinal Chemistry group. An initial lead from a small parallel library was found to be potent and selective in biochemical assays. Advanced compounds were the culmination of iterative library design and possess excellent biochemical and cellular potency, as well as acceptable PK and efficacy in animal models. PMID:19138845

  8. Discovery of XEN445: a potent and selective endothelial lipase inhibitor raises plasma HDL-cholesterol concentration in mice.

    PubMed

    Sun, Shaoyi; Dean, Richard; Jia, Qi; Zenova, Alla; Zhong, Jing; Grayson, Celene; Xie, Clark; Lindgren, Andrea; Samra, Pritpaul; Sojo, Luis; van Heek, Margaret; Lin, Linus; Percival, David; Fu, Jian-Min; Winther, Michael D; Zhang, Zaihui

    2013-12-15

    Endothelial lipase (EL) activity has been implicated in HDL metabolism and in atherosclerotic plaque development; inhibitors are proposed to be efficacious in the treatment of dyslipidemia related cardiovascular disease. We describe here the discovery of a novel class of anthranilic acids EL inhibitors. XEN445 (compound 13) was identified as a potent and selective EL inhibitor, that showed good ADME and PK properties, and demonstrated in vivo efficacy in raising plasma HDLc concentrations in mice. PMID:24211162

  9. Selectivity of microbial acyl-CoA: cholesterol acyltransferase inhibitors toward isozymes.

    PubMed

    Ohshiro, Taichi; Rudel, Lawrence L; Omura, Satoshi; Tomoda, Hiroshi

    2007-01-01

    The selectivity of microbial inhibitors of acyl-CoA: cholesterol acyltransferase (ACAT) toward the two isozymes, ACAT1 and ACAT2, was assessed in cell-based assays. Purpactin A (IC50 values of ACAT1 vs. IC50 values of ACAT2; 2.5 microM vs. 1.5 microM), terpendole C (10 microM vs. 10 microM), glisoprenin A (4.3 microM vs. 10 microM), spylidone (25 microM vs. 5.0 microM) and synthetic CL-283,546 (0.1 microM vs. 0.09 microM) inhibited ACAT1 and ACAT2 to similar extents. Beauveriolides I (0.6 microM vs. 20 microM) and III (0.9 microM vs. >20 microM) inhibited ACAT1 rather selectively, while pyripyropenes A (>80 microM vs. 0.07 microM), B (48 microM vs. 2.0 microM), C (32 microM vs. 0.36 microM) and D (38 microM vs. 1.5 microM) showed selective inhibition against ACAT2. In particular, pyripyropene A was found to be the most selective ACAT2 inhibitor with a selective index of more than 1,000. PMID:17390588

  10. Kinetic and Structural Studies of Phosphodiesterase-8A and Implication on the Inhibitor Selectivity

    SciTech Connect

    Wang, H.; Yan, Z; Yang, S; Cai, J; Robinson, H; Ke, H

    2008-01-01

    Cyclic nucleotide phosphodiesterase-8 (PDE8) is a family of cAMP-specific enzymes and plays important roles in many biological processes, including T-cell activation, testosterone production, adrenocortical hyperplasia, and thyroid function. However, no PDE8 selective inhibitors are available for trial treatment of human diseases. Here we report kinetic properties of the highly active PDE8A1 catalytic domain prepared from refolding and its crystal structures in the unliganded and 3-isobutyl-1-methylxanthine (IBMX) bound forms at 1.9 and 2.1 Angstroms resolutions, respectively. The PDE8A1 catalytic domain has a KM of 1.8 eM, Vmax of 6.1 emol/min/mg, a kcat of 4.0 s-1 for cAMP, and a KM of 1.6 mM, Vmax of 2.5 emol/min/mg, a kcat of 1.6 s-1 for cGMP, thus indicating that the substrate specificity of PDE8 is dominated by KM. The structure of the PDE8A1 catalytic domain has similar topology as those of other PDE families but contains two extra helices around Asn685-Thr710. Since this fragment is distant from the active site of the enzyme, its impact on the catalysis is unclear. The PDE8A1 catalytic domain is insensitive to the IBMX inhibition (IC50 = 700 eM). The unfavorable interaction of IBMX in the PDE8A1-IBMX structure suggests an important role of Tyr748 in the inhibitor binding. Indeed, the mutation of Tyr748 to phenylalanine increases the PDE8A1 sensitivity to several nonselective or family selective PDE inhibitors. Thus, the structural and mutagenesis studies provide not only insight into the enzymatic properties but also guidelines for design of PDE8 selective inhibitors.

  11. Discovery of a Selective Inhibitor of Oncogenic B-Raf Kinase With Potent Antimelanoma Activity

    SciTech Connect

    Tsai, J.; Lee, J.T.; Wang, W.; Zhang, J.; Cho, H.; Mamo, S.; Bremer, R.; Gillette, S.; Kong, J.; Haass, N.K.; Sproesser, K.; Li, L.; Smalley, K.S.M.; Fong, D.; Zhu, Y.-L.; Marimuthu, A.; Nguyen, H.; Lam, B.; Liu, J.; Cheung, I.; Rice, J.

    2009-05-26

    BRAF{sup V600E} is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting 'active' protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-Raf{sup V600E} with an IC{sub 50} of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4720 preferentially inhibits the active B-Raf{sup V600E} kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-Raf{sup V600E}-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-Raf{sup V600E}-positive cells. In B-Raf{sup V600E}-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-Raf{sup V600E}-driven tumors.

  12. 2-Alkoxy-3-(sulfonylarylaminomethylene)-chroman-4-ones as potent and selective inhibitors of ectonucleotidases.

    PubMed

    al-Rashida, Mariya; Batool, Gazala; Sattar, Almas; Ejaz, Syeda Abida; Khan, Samiullah; Lecka, Joanna; Sévigny, Jean; Hameed, Abdul; Iqbal, Jamshed

    2016-06-10

    A facile method for the modulation of 2-alkoxy side chain of 3-formylchromone enamines has been exploited for the synthesis of a series of 2-alkoxy-3-(sulfonylarylaminomethylene)-chroman-4-ones. This modulation was achieved by simply changing the alcoholic reaction media from methanol to ethanol, iso-propanol and n-butanol while reacting various 3-formylchromones with aminobenzenesulfonamides. Alcohols are sufficiently nucleophilic and add into the C2-C3 olefinic bond of 3-formylchromones without causing any ring cleavage. The resulting 2-alkoxy-3-(sulfonylarylaminomethylene)-chroman-4-ones were found to be potent and selective inhibitors of ecto-5'-nucleotidase and alkaline phosphatases (TNAP and IAP). Detailed enzyme kinetics studies revealed competitive inhibition against alkaline phosphatases and un-competitive inhibition against rat and human ecto-5'-nucleotidase. The most active TNAP inhibitor 23 (Ki = 0.078 ± 0.001 μM), exhibited 28 times more selectivity for TNAP over IAP (Ki = 2.18 ± 0.12 μM). Compound 9 was most active IAP inhibitor (Ki = 0.24 ± 0.01 μM), and was 300 times more selective towards IAP than TNAP (Ki = 72.9 ± 1.68 μM). Compound 40 was most active human ecto-5'-nucleotidase inhibitor exhibiting inhibition in low nanomolar range (Ki = 14 nM). PMID:27054295

  13. SCR7 is neither a selective nor a potent inhibitor of human DNA ligase IV.

    PubMed

    Greco, George E; Matsumoto, Yoshihiro; Brooks, Rhys C; Lu, Zhengfei; Lieber, Michael R; Tomkinson, Alan E

    2016-07-01

    DNA ligases are attractive therapeutics because of their involvement in completing the repair of almost all types of DNA damage. A series of DNA ligase inhibitors with differing selectivity for the three human DNA ligases were identified using a structure-based approach with one of these inhibitors being used to inhibit abnormal DNA ligase IIIα-dependent repair of DNA double-strand breaks (DSB)s in breast cancer, neuroblastoma and leukemia cell lines. Raghavan and colleagues reported the characterization of a derivative of one of the previously identified DNA ligase inhibitors, which they called SCR7 (designated SCR7-R in our experiments using SCR7). SCR7 appeared to show increased selectivity for DNA ligase IV, inhibit the repair of DSBs by the DNA ligase IV-dependent non-homologous end-joining (NHEJ) pathway, reduce tumor growth, and increase the efficacy of DSB-inducing therapeutic modalities in mouse xenografts. In attempting to synthesize SCR7, we encountered problems with the synthesis procedures and discovered discrepancies in its reported structure. We determined the structure of a sample of SCR7 and a related compound, SCR7-G, that is the major product generated by the published synthesis procedure for SCR7. We also found that SCR7-G has the same structure as the compound (SCR7-X) available from a commercial vendor (XcessBio). The various SCR7 preparations had similar activity in DNA ligation assay assays, exhibiting greater activity against DNA ligases I and III than DNA ligase IV. Furthermore, SCR7-R failed to inhibit DNA ligase IV-dependent V(D)J recombination in a cell-based assay. Based on our results, we conclude that SCR7 and the SCR7 derivatives are neither selective nor potent inhibitors of DNA ligase IV. PMID:27235626

  14. Structural basis of femtomolar inhibitors for acetylcholinesterase subtype selectivity: insights from computational simulations.

    PubMed

    Zhu, Xiao-Lei; Yu, Ning-Xi; Hao, Ge-Fei; Yang, Wen-Chao; Yang, Guang-Fu

    2013-04-01

    Acetylcholinesterase (AChE) is a key enzyme of the cholinergic nervous system. More than one gene encodes the synaptic AChE target. As the most potent known AChE inhibitor, the syn1-TZ2PA6 isomer was recently shown to have higher affinity as a reversible organic inhibitor of acetylcholinesterase1 (AChE1) than the anti1-TZ2PA6 isomer. Opposite selectivity has been shown for acetylcholinesterase2 (AChE2). In an attempt to understand the selectivity of the syn1-TZ2PA6 and anti1-TZ2PA6 isomers for AChE1 and AChE2, six molecular dynamics (MD) simulations were carried out with mouse AChE (mAChE, type of AChE1), Torpedo californica AChE (TcAChE, type of AChE1), and Drosophila melanogaster AChE (DmAChE, type of AChE2) bound with syn1-TZ2PA6 and anti1-TZ2PA6 isomers. Within the structure of the inhibitor, the 3,8-diamino-6-phenylphenanthridinium subunit and 9-amino-1,2,3,4-tetrahydroacridine subunit, via π-π interactions, made more favorable contributions to syn1-TZ2PA6 or anti1-TZ2PA6 isomer binding in the mAChE/TcAChE enzyme than the 1,2,3-triazole subunit. Compared to AChE1, the triazole subunit had increased binding energy with AChE2 due to a greater negative charge in the active site. The binding free energy calculated using the MM/PBSA method suggests that selectivity between AChE1 and AChE2 is mainly attributed to decreased binding affinity for the inhibitor. PMID:23500627

  15. Discovery of a selective inhibitor of oncogenic B-Raf kinase with potent antimelanoma activity

    PubMed Central

    Tsai, James; Lee, John T.; Wang, Weiru; Zhang, Jiazhong; Cho, Hanna; Mamo, Shumeye; Bremer, Ryan; Gillette, Sam; Kong, Jun; Haass, Nikolas K.; Sproesser, Katrin; Li, Ling; Smalley, Keiran S. M.; Fong, Daniel; Zhu, Yong-Liang; Marimuthu, Adhirai; Nguyen, Hoa; Lam, Billy; Liu, Jennifer; Cheung, Ivana; Rice, Julie; Suzuki, Yoshihisa; Luu, Catherine; Settachatgul, Calvin; Shellooe, Rafe; Cantwell, John; Kim, Sung-Hou; Schlessinger, Joseph; Zhang, Kam Y. J.; West, Brian L.; Powell, Ben; Habets, Gaston; Zhang, Chao; Ibrahim, Prabha N.; Hirth, Peter; Artis, Dean R.; Herlyn, Meenhard; Bollag, Gideon

    2008-01-01

    BRAFV600E is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting “active” protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-RafV600E with an IC50 of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4720 preferentially inhibits the active B-RafV600E kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-RafV600E-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-RafV600E-positive cells. In B-RafV600E-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-RafV600E-driven tumors. PMID:18287029

  16. Design and Structural Characterization of Potent and Selective Inhibitors of Phosphatidylinositol 4 Kinase IIIβ.

    PubMed

    Rutaganira, Florentine U; Fowler, Melissa L; McPhail, Jacob A; Gelman, Michael A; Nguyen, Khanh; Xiong, Anming; Dornan, Gillian L; Tavshanjian, Brandon; Glenn, Jeffrey S; Shokat, Kevan M; Burke, John E

    2016-03-10

    Type III phosphatidylinositol 4-kinase (PI4KIIIβ) is an essential enzyme in mediating membrane trafficking and is implicated in a variety of pathogenic processes. It is a key host factor mediating replication of RNA viruses. The design of potent and specific inhibitors of this enzyme will be essential to define its cellular roles and may lead to novel antiviral therapeutics. We previously reported the PI4K inhibitor PIK93, and this compound has defined key functions of PI4KIIIβ. However, this compound showed high cross reactivity with class I and III PI3Ks. Using structure-based drug design, we have designed novel potent and selective (>1000-fold over class I and class III PI3Ks) PI4KIIIβ inhibitors. These compounds showed antiviral activity against hepatitis C virus. The co-crystal structure of PI4KIIIβ bound to one of the most potent compounds reveals the molecular basis of specificity. This work will be vital in the design of novel PI4KIIIβ inhibitors, which may play significant roles as antiviral therapeutics. PMID:26885694

  17. Development and Characterization of 3-(Benzylsulfonamido)benzamides as Potent and Selective SIRT2 Inhibitors

    PubMed Central

    Khanfar, Mohammad A.; Quinti, Luisa; Wang, Hua; Choi, Soo Hyuk; Kazantsev, Aleksey G.; Silverman, Richard B.

    2014-01-01

    Inhibitors of sirtuin-2 deacetylase (SIRT2) have been shown to be protective in various models of Huntington's disease (HD) by decreasing polyglutamine aggregation, a hallmark of HD pathology. The present study was directed at optimizing the potency of SIRT2 inhibitors containing the neuroprotective sulfobenzoic acid scaffold and improving their pharmacology. To achieve that goal, 176 analogues were designed, synthesized, and tested in deacetylation assays against the activities of major human sirtuins SIRT1-3. This screen yielded 15 compounds with enhanced potency for SIRT2 inhibition and 11 compounds having SIRT2 inhibition equal to reference compound AK-1. The newly synthesized compounds also demonstrated higher SIRT2 selectivity over SIRT1 and SIRT3. These candidates were subjected to a dose-response bioactivity assay, measuring an increase in α-tubulin K40 acetylation in two neuronal cell lines, which yielded five compounds bioactive in both cell lines and eight compounds bioactive in at least one of the cell lines tested. These bioactive compounds were subsequently tested in a tertiary polyglutamine aggregation assay, which identified five inhibitors. ADME properties of the bioactive SIRT2 inhibitors were assessed, which revealed a significant improvement of the pharmacological properties of the new entities, reaching closer to the goal of a clinically-viable candidate. PMID:24602787

  18. A novel cofactor-binding mode in bacterial IMP dehydrogenases explains inhibitor selectivity

    DOE PAGESBeta

    Makowska-Grzyska, Magdalena; Kim, Youngchang; Maltseva, Natalia; Osipiuk, Jerzy; Gu, Minyi; Zhang, Minjia; Mandapati, Kavitha; Gollapalli, Deviprasad R.; Gorla, Suresh Kumar; Hedstrom, Lizbeth; et al

    2015-01-09

    The steadily rising frequency of emerging diseases and antibiotic resistance creates an urgent need for new drugs and targets. Inosine 5'-monophosphate dehydrogenase (IMP dehydrogenase or IMPDH) is a promising target for the development of new antimicrobial agents. IMPDH catalyzes the oxidation of IMP to XMP with the concomitant reduction of NAD+, which is the pivotal step in the biosynthesis of guanine nucleotides. Potent inhibitors of bacterial IMPDHs have been identified that bind in a structurally distinct pocket that is absent in eukaryotic IMPDHs. The physiological role of this pocket was not understood. Here, we report the structures of complexes withmore » different classes of inhibitors of Bacillus anthracis, Campylobacter jejuni, and Clostridium perfringens IMPDHs. These structures in combination with inhibition studies provide important insights into the interactions that modulate selectivity and potency. We also present two structures of the Vibrio cholerae IMPDH in complex with IMP/NAD+ and XMP/NAD+. In both structures, the cofactor assumes a dramatically different conformation than reported previously for eukaryotic IMPDHs and other dehydrogenases, with the major change observed for the position of the NAD+ adenosine moiety. More importantly, this new NAD+-binding site involves the same pocket that is utilized by the inhibitors. Thus, the bacterial IMPDH-specific NAD+-binding mode helps to rationalize the conformation adopted by several classes of prokaryotic IMPDH inhibitors. As a result, these findings offer a potential strategy for further ligand optimization.« less

  19. A Novel Cofactor-binding Mode in Bacterial IMP Dehydrogenases Explains Inhibitor Selectivity*

    PubMed Central

    Makowska-Grzyska, Magdalena; Kim, Youngchang; Maltseva, Natalia; Osipiuk, Jerzy; Gu, Minyi; Zhang, Minjia; Mandapati, Kavitha; Gollapalli, Deviprasad R.; Gorla, Suresh Kumar; Hedstrom, Lizbeth; Joachimiak, Andrzej

    2015-01-01

    The steadily rising frequency of emerging diseases and antibiotic resistance creates an urgent need for new drugs and targets. Inosine 5′-monophosphate dehydrogenase (IMP dehydrogenase or IMPDH) is a promising target for the development of new antimicrobial agents. IMPDH catalyzes the oxidation of IMP to XMP with the concomitant reduction of NAD+, which is the pivotal step in the biosynthesis of guanine nucleotides. Potent inhibitors of bacterial IMPDHs have been identified that bind in a structurally distinct pocket that is absent in eukaryotic IMPDHs. The physiological role of this pocket was not understood. Here, we report the structures of complexes with different classes of inhibitors of Bacillus anthracis, Campylobacter jejuni, and Clostridium perfringens IMPDHs. These structures in combination with inhibition studies provide important insights into the interactions that modulate selectivity and potency. We also present two structures of the Vibrio cholerae IMPDH in complex with IMP/NAD+ and XMP/NAD+. In both structures, the cofactor assumes a dramatically different conformation than reported previously for eukaryotic IMPDHs and other dehydrogenases, with the major change observed for the position of the NAD+ adenosine moiety. More importantly, this new NAD+-binding site involves the same pocket that is utilized by the inhibitors. Thus, the bacterial IMPDH-specific NAD+-binding mode helps to rationalize the conformation adopted by several classes of prokaryotic IMPDH inhibitors. These findings offer a potential strategy for further ligand optimization. PMID:25572472

  20. Structure-Guided Design of Group I Selective p21-Activated Kinase Inhibitors.

    PubMed

    Crawford, James J; Lee, Wendy; Aliagas, Ignacio; Mathieu, Simon; Hoeflich, Klaus P; Zhou, Wei; Wang, Weiru; Rouge, Lionel; Murray, Lesley; La, Hank; Liu, Ning; Fan, Peter W; Cheong, Jonathan; Heise, Christopher E; Ramaswamy, Sreemathy; Mintzer, Robert; Liu, Yanzhou; Chao, Qi; Rudolph, Joachim

    2015-06-25

    The p21-activated kinases (PAKs) play important roles in cytoskeletal organization, cellular morphogenesis, and survival and have generated significant attention as potential therapeutic targets for cancer. Following a high-throughput screen, we identified an aminopyrazole scaffold-based series that was optimized to yield group I selective PAK inhibitors. A structure-based design effort aimed at targeting the ribose pocket for both potency and selectivity led to much-improved group I vs II selectivity. Early lead compounds contained a basic primary amine, which was found to be a major metabolic soft spot with in vivo clearance proceeding predominantly via N-acetylation. We succeeded in identifying replacements with improved metabolic stability, leading to compounds with lower in vivo rodent clearance and excellent group I PAK selectivity. PMID:26030457

  1. Structural Bioinformatics-Based Prediction of Exceptional Selectivity of p38 MAP Kinase Inhibitor PH-797804

    SciTech Connect

    Xing, Li; Shieh, Huey S.; Selness, Shaun R.; Devraj, Rajesh V.; Walker, John K.; Devadas, Balekudru; Hope, Heidi R.; Compton, Robert P.; Schindler, John F.; Hirsch, Jeffrey L.; Benson, Alan G.; Kurumbail, Ravi G.; Stegeman, Roderick A.; Williams, Jennifer M.; Broadus, Richard M.; Walden, Zara; Monahan, Joseph B.; Pfizer

    2009-07-24

    PH-797804 is a diarylpyridinone inhibitor of p38{alpha} mitogen-activated protein (MAP) kinase derived from a racemic mixture as the more potent atropisomer (aS), first proposed by molecular modeling and subsequently confirmed by experiments. On the basis of structural comparison with a different biaryl pyrazole template and supported by dozens of high-resolution crystal structures of p38{alpha} inhibitor complexes, PH-797804 is predicted to possess a high level of specificity across the broad human kinase genome. We used a structural bioinformatics approach to identify two selectivity elements encoded by the TXXXG sequence motif on the p38{alpha} kinase hinge: (i) Thr106 that serves as the gatekeeper to the buried hydrophobic pocket occupied by 2,4-difluorophenyl of PH-797804 and (ii) the bidentate hydrogen bonds formed by the pyridinone moiety with the kinase hinge requiring an induced 180{sup o} rotation of the Met109-Gly110 peptide bond. The peptide flip occurs in p38{alpha} kinase due to the critical glycine residue marked by its conformational flexibility. Kinome-wide sequence mining revealed rare presentation of the selectivity motif. Corroboratively, PH-797804 exhibited exceptionally high specificity against MAP kinases and the related kinases. No cross-reactivity was observed in large panels of kinase screens (selectivity ratio of >500-fold). In cellular assays, PH-797804 demonstrated superior potency and selectivity consistent with the biochemical measurements. PH-797804 has met safety criteria in human phase I studies and is under clinical development for several inflammatory conditions. Understanding the rationale for selectivity at the molecular level helps elucidate the biological function and design of specific p38{alpha} kinase inhibitors.

  2. Physical Nature of Fatty Acid Amide Hydrolase Interactions with Its Inhibitors: Testing a Simple Nonempirical Scoring Model.

    PubMed

    Giedroyć-Piasecka, Wiktoria; Dyguda-Kazimierowicz, Edyta; Beker, Wiktor; Mor, Marco; Lodola, Alessio; Sokalski, W Andrzej

    2014-12-26

    Fatty acid amide hydrolase (FAAH) is an enzyme responsible for the deactivating hydrolysis of fatty acid ethanolamide neuromodulators. FAAH inhibitors have gained considerable interest due to their possible application in the treatment of anxiety, inflammation, and pain. In the context of inhibitor design, the availability of reliable computational tools for predicting binding affinity is still a challenging task, and it is now well understood that empirical scoring functions have several limitations that in principle could be overcome by quantum mechanics. Herein, systematic ab initio analyses of FAAH interactions with a series of inhibitors belonging to the class of the N-alkylcarbamic acid aryl esters have been performed. In contrast to our earlier studies of other classes of enzyme-inhibitor complexes, reasonable correlation with experimental results required us to consider correlation effects along with electrostatic term. Therefore, the simplest comprehensive nonempirical model allowing for qualitative predictions of binding affinities for FAAH ligands consists of electrostatic multipole and second-order dispersion terms. Such a model has been validated against the relative stabilities of the benchmark S66 set of biomolecular complexes. As it does not involve parameters fitted to experimentally derived data, this model offers a unique opportunity for generally applicable inhibitor design and virtual screening. PMID:25420234

  3. Design of potent and selective hybrid inhibitors of the mitotic kinase Nek2: SAR, structural biology and cellular activity

    PubMed Central

    Innocenti, Paolo; Cheung, Kwai-Ming J.; Solanki, Savade; Mas-Droux, Corine; Rowan, Fiona; Yeoh, Sharon; Boxall, Kathy; Westlake, Maura; Pickard, Lisa; Hardy, Tara; Baxter, Joanne E.; Aherne, G. Wynne; Bayliss, Richard; Fry, Andrew M.; Hoelder, Swen

    2013-01-01

    We report herein a series of Nek2 inhibitors based on an aminopyridine scaffold. These compounds have been designed by combining key elements of two previously discovered chemical series. Structure based design led to aminopyridine (R )-21, a potent and selective inhibitor able to modulate Nek2 activity in cells. PMID:22404346

  4. Structure-Based Design of an in Vivo Active Selective BRD9 Inhibitor

    PubMed Central

    2016-01-01

    Components of the chromatin remodelling switch/sucrose nonfermentable (SWI/SNF) complex are recurrently mutated in tumors, suggesting that altering the activity of the complex plays a role in oncogenesis. However, the role that the individual subunits play in this process is not clear. We set out to develop an inhibitor compound targeting the bromodomain of BRD9 in order to evaluate its function within the SWI/SNF complex. Here, we present the discovery and development of a potent and selective BRD9 bromodomain inhibitor series based on a new pyridinone-like scaffold. Crystallographic information on the inhibitors bound to BRD9 guided their development with respect to potency for BRD9 and selectivity against BRD4. These compounds modulate BRD9 bromodomain cellular function and display antitumor activity in an AML xenograft model. Two chemical probes, BI-7273 (1) and BI-9564 (2), were identified that should prove to be useful in further exploring BRD9 bromodomain biology in both in vitro and in vivo settings. PMID:26914985

  5. Ticlopidine in Its Prodrug Form Is a Selective Inhibitor of Human NTPDase1

    PubMed Central

    Künzli, Beat

    2014-01-01

    Nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), like other ectonucleotidases, controls extracellular nucleotide levels and consequently their (patho)physiological responses such as in thrombosis, inflammation, and cancer. Selective NTPDase1 inhibitors would therefore be very useful. We previously observed that ticlopidine in its prodrug form, which does not affect P2 receptor activity, inhibited the recombinant form of human NTPDase1 (Ki = 14 μM). Here we tested whether ticlopidine can be used as a selective inhibitor of NTPDase1. We confirmed that ticlopidine inhibits NTPDase1 in different forms and in different assays. The ADPase activity of intact HUVEC as well as of COS-7 cells transfected with human NTPDase1 was strongly inhibited by 100 µM ticlopidine, 99 and 86%, respectively. Ticlopidine (100 µM) completely inhibited the ATPase activity of NTPDase1 in situ as shown by enzyme histochemistry with human liver and pancreas sections. Ticlopidine also inhibited the activity of rat and mouse NTPDase1 and of potato apyrase. At 100 µM ticlopidine did not affect the activity of human NTPDase2, NTPDase3, and NTPDase8, nor of NPP1 and NPP3. Weak inhibition (10–20%) of NTPDase3 and -8 was observed at 1 mM ticlopidine. These results show that ticlopidine is a specific inhibitor of NTPDase1 that can be used in enzymatic and histochemistry assays. PMID:25180024

  6. Selective small molecule inhibitor of the Mycobacterium tuberculosis fumarate hydratase reveals an allosteric regulatory site

    PubMed Central

    Kasbekar, Monica; Fischer, Gerhard; Mott, Bryan T.; Yasgar, Adam; Hyvönen, Marko; Boshoff, Helena I. M.; Abell, Chris; Barry, Clifton E.; Thomas, Craig J.

    2016-01-01

    Enzymes in essential metabolic pathways are attractive targets for the treatment of bacterial diseases, but in many cases, the presence of homologous human enzymes makes them impractical candidates for drug development. Fumarate hydratase, an essential enzyme in the tricarboxylic acid (TCA) cycle, has been identified as one such potential therapeutic target in tuberculosis. We report the discovery of the first small molecule inhibitor, to our knowledge, of the Mycobacterium tuberculosis fumarate hydratase. A crystal structure at 2.0-Å resolution of the compound in complex with the protein establishes the existence of a previously unidentified allosteric regulatory site. This allosteric site allows for selective inhibition with respect to the homologous human enzyme. We observe a unique binding mode in which two inhibitor molecules interact within the allosteric site, driving significant conformational changes that preclude simultaneous substrate and inhibitor binding. Our results demonstrate the selective inhibition of a highly conserved metabolic enzyme that contains identical active site residues in both the host and the pathogen. PMID:27325754

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

    PubMed

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

    2015-07-01

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

  8. Potent and Selective Inhibitors of Human Reticulocyte 12/15-Lipoxygenase as Anti-Stroke Therapies

    PubMed Central

    2015-01-01

    A key challenge facing drug discovery today is variability of the drug target between species, such as with 12/15-lipoxygenase (12/15-LOX), which contributes to ischemic brain injury, but its human and rodent isozymes have different inhibitor specificities. In the current work, we have utilized a quantitative high-throughput (qHTS) screen to identify compound 1 (ML351), a novel chemotype for 12/15-LOX inhibition that has nanomolar potency (IC50 = 200 nM) against human 12/15-LOX and is protective against oxidative glutamate toxicity in mouse neuronal HT22 cells. In addition, it exhibited greater than 250-fold selectivity versus related LOX isozymes, was a mixed inhibitor, and did not reduce the active-site ferric ion. Lastly, 1 significantly reduced infarct size following permanent focal ischemia in a mouse model of ischemic stroke. As such, this represents the first report of a selective inhibitor of human 12/15-LOX with demonstrated in vivo activity in proof-of-concept mouse models of stroke. PMID:24684213

  9. Structure-Based Design of an in Vivo Active Selective BRD9 Inhibitor.

    PubMed

    Martin, Laetitia J; Koegl, Manfred; Bader, Gerd; Cockcroft, Xiao-Ling; Fedorov, Oleg; Fiegen, Dennis; Gerstberger, Thomas; Hofmann, Marco H; Hohmann, Anja F; Kessler, Dirk; Knapp, Stefan; Knesl, Petr; Kornigg, Stefan; Müller, Susanne; Nar, Herbert; Rogers, Catherine; Rumpel, Klaus; Schaaf, Otmar; Steurer, Steffen; Tallant, Cynthia; Vakoc, Christopher R; Zeeb, Markus; Zoephel, Andreas; Pearson, Mark; Boehmelt, Guido; McConnell, Darryl

    2016-05-26

    Components of the chromatin remodelling switch/sucrose nonfermentable (SWI/SNF) complex are recurrently mutated in tumors, suggesting that altering the activity of the complex plays a role in oncogenesis. However, the role that the individual subunits play in this process is not clear. We set out to develop an inhibitor compound targeting the bromodomain of BRD9 in order to evaluate its function within the SWI/SNF complex. Here, we present the discovery and development of a potent and selective BRD9 bromodomain inhibitor series based on a new pyridinone-like scaffold. Crystallographic information on the inhibitors bound to BRD9 guided their development with respect to potency for BRD9 and selectivity against BRD4. These compounds modulate BRD9 bromodomain cellular function and display antitumor activity in an AML xenograft model. Two chemical probes, BI-7273 (1) and BI-9564 (2), were identified that should prove to be useful in further exploring BRD9 bromodomain biology in both in vitro and in vivo settings. PMID:26914985

  10. Cheminformatics-driven discovery of selective, nanomolar inhibitors for staphylococcal pyruvate kinase.

    PubMed

    Axerio-Cilies, Peter; See, Raymond H; Zoraghi, Roya; Worral, Liam; Lian, Tian; Stoynov, Nikolay; Jiang, Jihong; Kaur, Sukhbir; Jackson, Linda; Gong, Huansheng; Swayze, Rick; Amandoron, Emily; Kumar, Nag S; Moreau, Anne; Hsing, Michael; Strynadka, Natalie C; McMaster, William R; Finlay, B Brett; Foster, Leonard J; Young, Robert N; Reiner, Neil E; Cherkasov, Artem

    2012-02-17

    We have recently mapped the protein interaction network of methicillin-resistant Staphylococcus aureus (MRSA), which revealed its scale-free organization with characteristic presence of highly connected hub proteins that are critical for bacterial survival. Here we report the discovery of inhibitors that are highly potent against one such hub target, staphylococcal pyruvate kinase (PK). Importantly, the developed compounds demonstrate complete selectivity for the bacterial enzyme compared to all human orthologues. The lead 91nM inhibitor IS-130 has been identified through ligand-based cheminformatic exploration of a chemical space around micromolar hits initially generated by experimental screening. The following crystallographic study resulted in identification of a tetrameric MRSA PK structure where IS-130 is bound to the interface between the protein's subunits. This newly described binding pocket is not present in otherwise highly similar human orthologues and can be effectively utilized for selective inhibition of bacterial PK. The following synthetic modifications of IS-130, guided by structure-based molecular modeling, resulted in the development of MRSA PK inhibitors with much improved antimicrobial properties. Considering a notable lack of recent reports on novel antibacterial targets and cognate antibacterial compounds, this study provides a valuable perspective on the development of a new generation of antimicrobials. Equally noteworthy, the results of the current work highlight the importance of rigorous cheminformatics-based exploration of the results of high-throughput experiments. PMID:22066782

  11. Selective and potent urea inhibitors of Cryptosporidium parvum inosine 5′ monophosphate dehydrogenase

    PubMed Central

    Gorla, Suresh Kumar; Kavitha, Mandapati; Zhang, Minjia; Liu, Xiaoping; Sharling, Lisa; Gollapalli, Deviprasad R.; Striepen, Boris; Hedstrom, Lizbeth; Cuny, Gregory D.

    2012-01-01

    Cryptosporidium parvum and related species are zoonotic intracellular parasites of the intestine. Cryptosporidium is a leading cause of diarrhea in small children around the world. Infection can cause severe pathology in children and immunocompromised patients. This waterborne parasite is resistant to common methods of water treatment and therefore a prominent threat to drinking and recreation water even in countries with strong water safety systems. The drugs currently used to combat these organisms are ineffective. Genomic analysis revealed that the parasite relies solely on inosine-5′-monophosphate dehydrogenase (IMPDH) for the biosynthesis of guanine nucleotides. Herein, we report a selective urea-based inhibitor of C. parvum IMPDH (CpIMPDH) identified by high throughput screening. We performed a SAR study of these inhibitors with some analogues exhibiting high potency (IC50 < 2 nM) against CpIMPDH, excellent selectivity > 1000-fold versus human IMPDH type 2 and good stability in mouse liver microsomes. A subset of inhibitors also displayed potent antiparasitic activity in a Toxoplasma gondii model. PMID:22950983

  12. LP99: Discovery and Synthesis of the First Selective BRD7/9 Bromodomain Inhibitor**

    PubMed Central

    Clark, Peter G K; Vieira, Lucas C C; Tallant, Cynthia; Fedorov, Oleg; Singleton, Dean C; Rogers, Catherine M; Monteiro, Octovia P; Bennett, James M; Baronio, Roberta; Müller, Susanne; Daniels, Danette L; Méndez, Jacqui; Knapp, Stefan; Brennan, Paul E; Dixon, Darren J

    2015-01-01

    The bromodomain-containing proteins BRD9 and BRD7 are part of the human SWI/SNF chromatin-remodeling complexes BAF and PBAF. To date, no selective inhibitor for BRD7/9 has been reported despite its potential value as a biological tool or as a lead for future therapeutics. The quinolone-fused lactam LP99 is now reported as the first potent and selective inhibitor of the BRD7 and BRD9 bromodomains. Development of LP99 from a fragment hit was expedited through balancing structure-based inhibitor design and biophysical characterization against tractable chemical synthesis: Complexity-building nitro-Mannich/lactamization cascade processes allowed for early structure–activity relationship studies whereas an enantioselective organocatalytic nitro-Mannich reaction enabled the synthesis of the lead scaffold in enantioenriched form and on scale. This epigenetic probe was shown to inhibit the association of BRD7 and BRD9 to acetylated histones in vitro and in cells. Moreover, LP99 was used to demonstrate that BRD7/9 plays a role in regulating pro-inflammatory cytokine secretion. PMID:25864491

  13. Selective small molecule inhibitor of the Mycobacterium tuberculosis fumarate hydratase reveals an allosteric regulatory site.

    PubMed

    Kasbekar, Monica; Fischer, Gerhard; Mott, Bryan T; Yasgar, Adam; Hyvönen, Marko; Boshoff, Helena I M; Abell, Chris; Barry, Clifton E; Thomas, Craig J

    2016-07-01

    Enzymes in essential metabolic pathways are attractive targets for the treatment of bacterial diseases, but in many cases, the presence of homologous human enzymes makes them impractical candidates for drug development. Fumarate hydratase, an essential enzyme in the tricarboxylic acid (TCA) cycle, has been identified as one such potential therapeutic target in tuberculosis. We report the discovery of the first small molecule inhibitor, to our knowledge, of the Mycobacterium tuberculosis fumarate hydratase. A crystal structure at 2.0-Å resolution of the compound in complex with the protein establishes the existence of a previously unidentified allosteric regulatory site. This allosteric site allows for selective inhibition with respect to the homologous human enzyme. We observe a unique binding mode in which two inhibitor molecules interact within the allosteric site, driving significant conformational changes that preclude simultaneous substrate and inhibitor binding. Our results demonstrate the selective inhibition of a highly conserved metabolic enzyme that contains identical active site residues in both the host and the pathogen. PMID:27325754

  14. Discovery of potent and selective benzothiazole hydrazone inhibitors of Bcl-XL.

    PubMed

    Sleebs, Brad E; Kersten, Wilhemus J A; Kulasegaram, Sanji; Nikolakopoulos, George; Hatzis, Effie; Moss, Rebecca M; Parisot, John P; Yang, Hong; Czabotar, Peter E; Fairlie, W Douglas; Lee, Erinna F; Adams, Jerry M; Chen, Lin; van Delft, Mark F; Lowes, Kym N; Wei, Andrew; Huang, David C S; Colman, Peter M; Street, Ian P; Baell, Jonathan B; Watson, Keith; Lessene, Guillaume

    2013-07-11

    Developing potent molecules that inhibit Bcl-2 family mediated apoptosis affords opportunities to treat cancers via reactivation of the cell death machinery. We describe the hit-to-lead development of selective Bcl-XL inhibitors originating from a high-throughput screening campaign. Small structural changes to the hit compound increased binding affinity more than 300-fold (to IC50 < 20 nM). This molecular series exhibits drug-like characteristics, low molecular weights (Mw < 450), and unprecedented selectivity for Bcl-XL. Surface plasmon resonance experiments afford strong evidence of binding affinity within the hydrophobic groove of Bcl-XL. Biological experiments using engineered Mcl-1 deficient mouse embryonic fibroblasts (MEFs, reliant only on Bcl-XL for survival) and Bax/Bak deficient MEFs (insensitive to selective activation of Bcl-2-driven apoptosis) support a mechanism-based induction of apoptosis. This manuscript describes the first series of selective small-molecule inhibitors of Bcl-XL and provides promising leads for the development of efficacious therapeutics against solid tumors and chemoresistant cancer cell lines. PMID:23767404

  15. Inhibitor focusing: direct selection of drug targets from proteomes using activity-based probes.

    PubMed

    Nomanbhoy, Tyzoon K; Rosenblum, Jonathan; Aban, Arwin; Burbaum, Jonathan J

    2003-02-01

    In the latter stages of drug discovery and development, assays that establish drug selectivity and toxicity are important when side effects, which are often due to lack of specificity, determine drug candidate viability. There has been no comprehensive or systematic methodology to measure these factors outside of whole-animal assays, and such phenomenological assays generally fail to establish the additional targets of a given small molecule, or the molecular origin of toxicity. Consequently, small-molecule development programs destined for failure often reach advanced stages of testing, and the money and time invested in such programs could be saved if information on selectivity were available early in the process. Here, we present a methodology that utilizes chemical ABPs in combination with small-molecule inhibitors to selectively label small-molecule binding sites in whole proteomic samples. In principle, the ABP and small molecule will compete for similar binding sites, such that the small molecule will protect against modification by the ABP. Thus, after removal of the small molecule, the binding site for the ABP will be revealed, and a second probe can then be used to label the small-molecule binding sites selectively. To demonstrate this experimentally, we mapped the binding sites of the DPP4 inhibitor, IT, in a number of different tissue types. PMID:15090140

  16. (E)-3-Heteroarylidenechroman-4-ones as potent and selective monoamine oxidase-B inhibitors.

    PubMed

    Desideri, Nicoletta; Proietti Monaco, Luca; Fioravanti, Rossella; Biava, Mariangela; Yáñez, Matilde; Alcaro, Stefano; Ortuso, Francesco

    2016-07-19

    A series of (E)-3-heteroarylidenechroman-4-ones (1a-r) was designed, synthesized and investigated in vitro for their ability to inhibit the enzymatic activity of both human monoamine oxidase (hMAO) isoforms, hMAO-A and hMAO-B. All the compounds were found to be selective hMAO-B inhibitors showing IC50 values in the nanomolar or micromolar range. (E)-5,7-Dichloro-3-{[(2-(dimethylamino)pyrimidin-5-yl]methylene}chroman-4-one (1c) was the most interesting compound identified in this study, endowed with higher hMAO-B potency (IC50 = 10.58 nM) and selectivity (SI > 9452) with respect to the reference selective inhibitor selegiline (IC50 = 19.60 nM, IC50 > 3431). Molecular modelling studies were performed for rationalizing at molecular level the target selective inhibition of our compounds, revealing a remarkable contribution of hydrogen bond network and water solvent. PMID:27135371

  17. A novel HCV NS3 protease mutation selected by combination treatment of the protease inhibitor boceprevir and NS5B polymerase inhibitors.

    PubMed

    Chase, Robert; Skelton, Angela; Xia, Ellen; Curry, Stephanie; Liu, Shaotang; McMonagle, Patricia; Huang, H-C; Tong, Xiao

    2009-11-01

    Boceprevir (SCH 503034) is an orally active novel inhibitor of the hepatitis C virus (HCV) NS3 protease currently in clinical development for the treatment of hepatitis C. In this in vitro study, we demonstrate that combination of boceprevir with a nucleoside analog or a non-nucleoside HCV NS5B polymerase inhibitor was superior to treatment by single agents in inhibiting viral RNA replication in replicon cells. In the presence of boceprevir (at 5xEC(90)), the addition of 2'-C-methyl-adenosine or an indole-N-acetamide targeting the polymerase finger-loop site (at 1xEC(90)) significantly reduced the emergence of resistant replicon colonies. A higher dose (5xEC(90)) of either of the polymerase inhibitors in combination with boceprevir suppressed replicon resistance further to below detectable levels. Sequencing analysis of replicon cells selected by the combination treatment revealed known resistance mutations to the two polymerase inhibitors but no previously reported resistance mutations to boceprevir. Interestingly, a novel mutation (M175L) in the protease domain was identified. The dually resistant replicon cells were monitored for over 30 passages and sensitivity to polymerase inhibitors was found to decrease over time in a manner that correlated with the increasing prevalence of specific resistance mutations. Importantly, these cells remained sensitive to interferon-alpha and different classes of polymerase inhibitors. These findings support the rationale for clinical evaluation of combination treatment of HCV protease and polymerase inhibitors. PMID:19747948

  18. Amine substitution of quinazolinones leads to selective nanomolar AChE inhibitors with 'inverted' binding mode.

    PubMed

    Darras, Fouad H; Wehle, Sarah; Huang, Guozheng; Sotriffer, Christoph A; Decker, Michael

    2014-09-01

    Selective and nanomolar acetylcholinesterase inhibitors were obtained by connecting tri- and tetracyclic quinazolinones-previously described as moderately active and unselective cholinesterase (ChE) inhibitors-via a hydroxyl group in para position to an anilinic nitrogen with different amines linked via a three carbon atom spacer. These tri- and tetracyclic quinazolinones containing different alicyclic ring sizes and connected to tertiary amines were docked to a high-resolution hAChE crystal structure to investigate the preferred binding mode in relation to results obtained by experimental structure-activity relationships. While the 'classical orientation' locating the heterocycle in the active site was rarely found, an alternative binding mode with the basic aliphatic amine in the active center ('inverted' orientation) was obtained for most compounds. Analyses of extended SARs based on this inverted binding mode are able to explain the compounds' binding affinities at AChE. PMID:25047936

  19. Drug interactions with selective serotonin reuptake inhibitors, especially with other psychotropics.

    PubMed

    2001-02-01

    (1) Selective serotonin reuptake inhibitors (SSRIs) are involved in many drug interactions with potentially serious clinical consequences. (2) These interactions involve all SSRIs but particularly fluoxetine, which is the best-studied antidepressant in this family. (3) Because of their long elimination half-life (particularly fluoxetine) the risk of interactions persists for several days or even weeks after SSRI withdrawal. (4) Drug interactions with clinical consequences usually involve combinations of an SSRI with other psychotropics, especially monoamine oxidase inhibitor (MAOI) and tricyclic antidepressants, clozapine, lithium, methadone, etc. (5) The clinical consequences of drug interactions with SSRI are either due to overdosing of the drug combined, or to a serotonin syndrome with neuromuscular and vegetative (autonomic) symptoms. (6) Interactions with a number of other drugs have been reported, especially carbamazepine, phenytoin and oral anticoagulants, with a risk of overdose of these drugs. (7) The risk of hyponatraemia linked to SSRIs seems to be increased during concomitant treatment with diuretics. PMID:11503857

  20. Triazolopyridines as selective JAK1 inhibitors: from hit identification to GLPG0634.

    PubMed

    Menet, Christel J; Fletcher, Stephen R; Van Lommen, Guy; Geney, Raphael; Blanc, Javier; Smits, Koen; Jouannigot, Nolwenn; Deprez, Pierre; van der Aar, Ellen M; Clement-Lacroix, Philippe; Lepescheux, Liên; Galien, René; Vayssiere, Béatrice; Nelles, Luc; Christophe, Thierry; Brys, Reginald; Uhring, Muriel; Ciesielski, Fabrice; Van Rompaey, Luc

    2014-11-26

    Janus kinases (JAK1, JAK2, JAK3, and TYK2) are involved in the signaling of multiple cytokines important in cellular function. Blockade of the JAK-STAT pathway with a small molecule has been shown to provide therapeutic immunomodulation. Having identified JAK1 as a possible new target for arthritis at Galapagos, the compound library was screened against JAK1, resulting in the identification of a triazolopyridine-based series of inhibitors represented by 3. Optimization within this chemical series led to identification of GLPG0634 (65, filgotinib), a selective JAK1 inhibitor currently in phase 2B development for RA and phase 2A development for Crohn's disease (CD). PMID:25369270

  1. Discovery of selective and orally available spiro-3-piperidyl ATP-competitive MK2 inhibitors.

    PubMed

    Kaptein, Allard; Oubrie, Arthur; de Zwart, Edwin; Hoogenboom, Niels; de Wit, Joeri; van de Kar, Bas; van Hoek, Maaike; Vogel, Gerard; de Kimpe, Vera; Schultz-Fademrecht, Carsten; Borsboom, Judith; van Zeeland, Mario; Versteegh, Judith; Kazemier, Bert; de Roos, Jeroen; Wijnands, Frank; Dulos, John; Jaeger, Martin; Leandro-Garcia, Paula; Barf, Tjeerd

    2011-06-15

    The identification of a potent, selective, and orally available MK2 inhibitor series is described. The initial absence of oral bioavailability was successfully tackled by moving the basic nitrogen of the spiro-4-piperidyl moiety towards the electron-deficient pyrrolepyridinedione core, thereby reducing the pK(a) and improving Caco-2 permeability. The resulting racemic spiro-3-piperidyl analogues were separated by chiral preparative HPLC, and the activity towards MK2 inhibition was shown to reside mostly in the first eluting stereoisomer. This led to the identification of new MK2 inhibitors, such as (S)-23, with low nanomolar biochemical inhibition (EC(50) 7.4 nM) and submicromolar cellular target engagement activity (EC(50) 0.5 μM). PMID:21565498

  2. Selective Gelatinase Inhibitor Neuroprotective Agents Cross the Blood-Brain Barrier

    PubMed Central

    2012-01-01

    SB-3CT, a potent and selective inhibitor of matrix metalloproteinase-2 and -9, has shown efficacy in several animal models of neurological diseases. One of the greatest challenges in the development of therapeutics for neurological diseases is the inability of drugs to cross the blood-brain barrier. A sensitive bioanalytical method based on ultraperformance liquid chromatography with multiple-reaction monitoring detection was developed to measure levels of SB-3CT, its active metabolite, the α-methyl analogue, and its p-hydroxy metabolite in plasma and brain. The compounds are rapidly absorbed and are readily distributed to the brain. The pharmacokinetic properties of these gelatinase inhibitors and the efficacy shown by SB-3CT in animal models of stroke, subarachnoid hemorrhage, and spinal cord injury indicate that this class of compounds holds considerable promise in the treatment of diseases of the central nervous system. PMID:23077716

  3. Discovery and Optimization of Potent, Selective, and in Vivo Efficacious 2-Aryl Benzimidazole BCATm Inhibitors.

    PubMed

    Deng, Hongfeng; Zhou, Jingye; Sundersingh, Flora; Messer, Jeffrey A; Somers, Donald O; Ajakane, Myriam; Arico-Muendel, Christopher C; Beljean, Arthur; Belyanskaya, Svetlana L; Bingham, Ryan; Blazensky, Emily; Boullay, Anne-Benedicte; Boursier, Eric; Chai, Jing; Carter, Paul; Chung, Chun-Wa; Daugan, Alain; Ding, Yun; Herry, Kenny; Hobbs, Clare; Humphries, Eric; Kollmann, Christopher; Nguyen, Van Loc; Nicodeme, Edwige; Smith, Sarah E; Dodic, Nerina; Ancellin, Nicolas

    2016-04-14

    To identify BCATm inhibitors suitable for in vivo study, Encoded Library Technology (ELT) was used to affinity screen a 117 million member benzimidazole based DNA encoded library, which identified an inhibitor series with both biochemical and cellular activities. Subsequent SAR studies led to the discovery of a highly potent and selective compound, 1-(3-(5-bromothiophene-2-carboxamido)cyclohexyl)-N-methyl-2-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamide (8b) with much improved PK properties. X-ray structure revealed that 8b binds to the active site of BACTm in a unique mode via multiple H-bond and van der Waals interactions. After oral administration, 8b raised mouse blood levels of all three branched chain amino acids as a consequence of BCATm inhibition. PMID:27096045

  4. Development of novel dual binders as potent, selective, and orally bioavailable tankyrase inhibitors.

    PubMed

    Hua, Zihao; Bregman, Howard; Buchanan, John L; Chakka, Nagasree; Guzman-Perez, Angel; Gunaydin, Hakan; Huang, Xin; Gu, Yan; Berry, Virginia; Liu, Jingzhou; Teffera, Yohannes; Huang, Liyue; Egge, Bryan; Emkey, Renee; Mullady, Erin L; Schneider, Steve; Andrews, Paul S; Acquaviva, Lisa; Dovey, Jennifer; Mishra, Ankita; Newcomb, John; Saffran, Douglas; Serafino, Randy; Strathdee, Craig A; Turci, Susan M; Stanton, Mary; Wilson, Cindy; Dimauro, Erin F

    2013-12-27

    Tankyrases (TNKS1 and TNKS2) are proteins in the poly ADP-ribose polymerase (PARP) family. They have been shown to directly bind to axin proteins, which negatively regulate the Wnt pathway by promoting β-catenin degradation. Inhibition of tankyrases may offer a novel approach to the treatment of APC-mutant colorectal cancer. Hit compound 8 was identified as an inhibitor of tankyrases through a combination of substructure searching of the Amgen compound collection based on a minimal binding pharmacophore hypothesis and high-throughput screening. Herein we report the structure- and property-based optimization of compound 8 leading to the identification of more potent and selective tankyrase inhibitors 22 and 49 with improved pharmacokinetic properties in rodents, which are well suited as tool compounds for further in vivo validation studies. PMID:24294969

  5. Discovery of GNF-5837, a Selective TRK Inhibitor with Efficacy in Rodent Cancer Tumor Models

    PubMed Central

    2012-01-01

    Neurotrophins and their receptors (TRKs) play key roles in the development of the nervous system and the maintenance of the neural network. Accumulating evidence points to their role in malignant transformations, chemotaxis, metastasis, and survival signaling and may contribute to the pathogenesis of a variety of tumors of both neural and non-neural origin. By screening the GNF kinase collection, a series of novel oxindole inhibitors of TRKs were identified. Optimization led to the identification of GNF-5837 (22), a potent, selective, and orally bioavailable pan-TRK inhibitor that inhibited tumor growth in a mouse xenograft model derived from RIE cells expressing both TRKA and NGF. The properties of 22 make it a good tool for the elucidation of TRK biology in cancer and other nononcology indications. PMID:24900443

  6. Discovery of GNF-5837, a Selective TRK Inhibitor with Efficacy in Rodent Cancer Tumor Models.

    PubMed

    Albaugh, Pam; Fan, Yi; Mi, Yuan; Sun, Fangxian; Adrian, Francisco; Li, Nanxin; Jia, Yong; Sarkisova, Yelena; Kreusch, Andreas; Hood, Tami; Lu, Min; Liu, Guoxun; Huang, Shenlin; Liu, Zuosheng; Loren, Jon; Tuntland, Tove; Karanewsky, Donald S; Seidel, H Martin; Molteni, Valentina

    2012-02-01

    Neurotrophins and their receptors (TRKs) play key roles in the development of the nervous system and the maintenance of the neural network. Accumulating evidence points to their role in malignant transformations, chemotaxis, metastasis, and survival signaling and may contribute to the pathogenesis of a variety of tumors of both neural and non-neural origin. By screening the GNF kinase collection, a series of novel oxindole inhibitors of TRKs were identified. Optimization led to the identification of GNF-5837 (22), a potent, selective, and orally bioavailable pan-TRK inhibitor that inhibited tumor growth in a mouse xenograft model derived from RIE cells expressing both TRKA and NGF. The properties of 22 make it a good tool for the elucidation of TRK biology in cancer and other nononcology indications. PMID:24900443

  7. Furafylline is a potent and selective inhibitor of cytochrome P450IA2 in man.

    PubMed Central

    Sesardic, D; Boobis, A R; Murray, B P; Murray, S; Segura, J; de la Torre, R; Davies, D S

    1990-01-01

    1. Furafylline (1,8-dimethyl-3-(2'-furfuryl)methylxanthine) is a methylxanthine derivative that was introduced as a long-acting replacement for theophylline in the treatment of asthma. Administration of furafylline was associated with an elevation in plasma levels of caffeine, due to inhibition of caffeine oxidation, a reaction catalysed by one or more hydrocarbon-inducible isoenzymes of P450. We have now investigated the selectivity of inhibition of human monooxygenase activities by furafylline. 2. Furafylline was a potent, non-competitive inhibitor of high affinity phenacetin O-deethylase activity of microsomal fractions of human liver, a reaction catalysed by P450IA2, with an IC50 value of 0.07 microM. 3. Furafylline had either very little or no effect on human monooxygenase activities catalysed by other isoenzymes of P450, including P450IID1, P450IIC, P450IIA. Of particular interest, furafylline did not inhibit P450IA1, assessed from aryl hydrocarbon hydroxylase activity of placental samples from women who smoked cigarettes. 4. It is concluded that furafylline is a highly selective inhibitor of P450IA2 in man. 5. Furafylline was a potent inhibitor of the N3-demethylation of caffeine and of a component of the N1- and N7-demethylation. This confirms earlier suggestions that caffeine is a selective substrate of a hydrocarbon-inducible isoenzyme of P450 in man, and identifies this as P450IA2. Thus, caffeine N3-demethylation should provide a good measure of the activity of P450IA in vivo in man. 6. Although furafylline selectively inhibited P450IA2, relative to P450IA1, in the rat, this was at 1000-times the concentration required to inhibit the human isoenzyme, suggesting a major difference in the active site geometry between the human and the rat orthologues of P50IA2. PMID:2378786

  8. Computational study of Gleevec and G6G reveals molecular determinants of kinase inhibitor selectivity

    SciTech Connect

    Lin, Yen -Lin; Meng, Yilin; Huang, Lei; Roux, Benoît

    2014-10-22

    Gleevec is a potent inhibitor of Abl tyrosine kinase but not of the highly homologous c-Src kinase. Because the ligand binds to an inactive form of the protein in which an Asp-Phe-Gly structural motif along the activation loop adopts a so-called DFG-out conformation, it was suggested that binding specificity was controlled by a “conformational selection” mechanism. In this context, the binding affinity displayed by the kinase inhibitor G6G poses an intriguing challenge. Although it possesses a chemical core very similar to that of Gleevec, G6G is a potent inhibitor of both Abl and c-Src kinases. Both inhibitors bind to the DFG-out conformation of the kinases, which seems to be in contradiction with the conformational selection mechanism. To address this issue and display the hidden thermodynamic contributions affecting the binding selectivity, molecular dynamics free energy simulations with explicit solvent molecules were carried out. Relative to Gleevec, G6G forms highly favorable van der Waals dispersive interactions upon binding to the kinases via its triazine functional group, which is considerably larger than the corresponding pyridine moiety in Gleevec. Upon binding of G6G to c-Src, these interactions offset the unfavorable free energy cost of the DFG-out conformation. When binding to Abl, however, G6G experiences an unfavorable free energy penalty due to steric clashes with the phosphate-binding loop, yielding an overall binding affinity that is similar to that of Gleevec. Such steric clashes are absent when G6G binds to c-Src, due to the extended conformation of the phosphate-binding loop.

  9. Computational study of Gleevec and G6G reveals molecular determinants of kinase inhibitor selectivity

    DOE PAGESBeta

    Lin, Yen -Lin; Meng, Yilin; Huang, Lei; Roux, Benoît

    2014-10-22

    Gleevec is a potent inhibitor of Abl tyrosine kinase but not of the highly homologous c-Src kinase. Because the ligand binds to an inactive form of the protein in which an Asp-Phe-Gly structural motif along the activation loop adopts a so-called DFG-out conformation, it was suggested that binding specificity was controlled by a “conformational selection” mechanism. In this context, the binding affinity displayed by the kinase inhibitor G6G poses an intriguing challenge. Although it possesses a chemical core very similar to that of Gleevec, G6G is a potent inhibitor of both Abl and c-Src kinases. Both inhibitors bind to themore » DFG-out conformation of the kinases, which seems to be in contradiction with the conformational selection mechanism. To address this issue and display the hidden thermodynamic contributions affecting the binding selectivity, molecular dynamics free energy simulations with explicit solvent molecules were carried out. Relative to Gleevec, G6G forms highly favorable van der Waals dispersive interactions upon binding to the kinases via its triazine functional group, which is considerably larger than the corresponding pyridine moiety in Gleevec. Upon binding of G6G to c-Src, these interactions offset the unfavorable free energy cost of the DFG-out conformation. When binding to Abl, however, G6G experiences an unfavorable free energy penalty due to steric clashes with the phosphate-binding loop, yielding an overall binding affinity that is similar to that of Gleevec. Such steric clashes are absent when G6G binds to c-Src, due to the extended conformation of the phosphate-binding loop.« less

  10. Nonpeptidic Selective Inhibitors of the Chymotrypsin-Like (β5 i) Subunit of the Immunoproteasome.

    PubMed

    Sosič, Izidor; Gobec, Martina; Brus, Boris; Knez, Damijan; Živec, Matej; Konc, Janez; Lešnik, Samo; Ogrizek, Mitja; Obreza, Aleš; Žigon, Dušan; Janežič, Dušanka; Mlinarič-Raščan, Irena; Gobec, Stanislav

    2016-05-01

    Elevated expression of the immunoproteasome has been associated with autoimmune diseases, inflammatory diseases, and various types of cancer. Selective inhibitors of the immunoproteasome are not only scarce, but also almost entirely restricted to peptide-based compounds. Herein, we describe nonpeptidic reversible inhibitors that selectively block the chymotrypsin-like (β5i) subunit of the human immunoproteasome in the low micromolar range. The most potent of the reversibly acting compounds were then converted into covalent, irreversible, nonpeptidic inhibitors that retained selectivity for the β5i subunit. In addition, these inhibitors discriminate between the immunoproteasome and the constitutive proteasome in cell-based assays. Along with their lack of cytotoxicity, these data point to these nonpeptidic compounds being suitable for further investigation as β5i-selective probes for possible application in noncancer diseases related to the immunoproteasome. PMID:27037901

  11. Overcoming mutagenicity and ion channel activity: optimization of selective spleen tyrosine kinase inhibitors.

    PubMed

    Ellis, J Michael; Altman, Michael D; Bass, Alan; Butcher, John W; Byford, Alan J; Donofrio, Anthony; Galloway, Sheila; Haidle, Andrew M; Jewell, James; Kelly, Nancy; Leccese, Erica K; Lee, Sandra; Maddess, Matthew; Miller, J Richard; Moy, Lily Y; Osimboni, Ekundayo; Otte, Ryan D; Reddy, M Vijay; Spencer, Kerrie; Sun, Binyuan; Vincent, Stella H; Ward, Gwendolyn J; Woo, Grace H C; Yang, Chiming; Houshyar, Hani; Northrup, Alan B

    2015-02-26

    Development of a series of highly kinome-selective spleen tyrosine kinase (Syk) inhibitors with favorable druglike properties is described. Early leads were discovered through X-ray crystallographic analysis, and a systematic survey of cores within a selected chemical space focused on ligand binding efficiency. Attenuation of hERG ion channel activity inherent within the initial chemotype was guided through modulation of physicochemical properties including log D, PSA, and pKa. PSA proved most effective for prospective compound design. Further profiling of an advanced compound revealed bacterial mutagenicity in the Ames test using TA97a Salmonella strain, and subsequent study demonstrated that this mutagenicity was pervasive throughout the series. Identification of intercalation as a likely mechanism for the mutagenicity-enabled modification of the core scaffold. Implementation of a DNA binding assay as a prescreen and models in DNA allowed resolution of the mutagenicity risk, affording molecules with favorable potency, selectivity, pharmacokinetic, and off-target profiles. PMID:25625541

  12. Discovery of Pyridyl Bis(oxy)dibenzimidamide Derivatives as Selective Matriptase Inhibitors.

    PubMed

    Goswami, Rajeev; Mukherjee, Subhendu; Wohlfahrt, Gerd; Ghadiyaram, Chakshusmathi; Nagaraj, Jwala; Chandra, Beeram Ravi; Sistla, Ramesh K; Satyam, Leena K; Samiulla, Dodheri S; Moilanen, Anu; Subramanya, Hosahalli S; Ramachandra, Murali

    2013-12-12

    Matriptase belongs to trypsin-like serine proteases involved in matrix remodeling/degradation, growth regulation, survival, motility, and cell morphogenesis. Herein, we report a structure-based approach, which led to the discovery of sulfonamide and amide derivatives of pyridyl bis(oxy)benzamidine as potent and selective matriptase inhibitors. Co-crystal structures of selected compounds in complex with matriptase supported compound designing. Additionally, WaterMap analyses indicated the possibility of occupying a distinct pocket within the catalytic domain, exploration of which resulted in >100-fold improvement in potency. Co-crystal structure of 10 with matriptase revealed critical interactions leading to potent target inhibition and selectivity against other serine proteases. PMID:24900621

  13. Role of Positive Selection in Functional Divergence of Mammalian Neuronal Apoptosis Inhibitor Proteins during Evolution

    PubMed Central

    Kong, Fanzhi; Su, Zhaoliang; Zhou, Chenglin; Sun, Caixia; Liu, Yanfang; Zheng, Dong; Yuan, Hongyan; Yin, Jingping; Fang, Jie; Wang, Shengjun; Xu, Huaxi

    2011-01-01

    Neuronal apoptosis inhibitor proteins (NAIPs) are members of Nod-like receptor (NLR) protein family. Recent research demostrated that some NAIP genes were strongly associated with both innate immunity and many inflammatory diseases in humans. However, no similar phenomena have been reported in other mammals. Furthermore, some NAIP genes have undergone pseudogenization or have been lost during the evolution of some higher mammals. We therefore aimed to determine if functional divergence had occurred, and if natural selection had played an important role in the evolution of these genes. The results showed that NAIP genes have undergone pseudogenization and functional divergence, driven by positive selection. Positive selection has also influenced NAIP protein structure, resulting in further functional divergence. PMID:22131819

  14. Discovery of Pyridyl Bis(oxy)dibenzimidamide Derivatives as Selective Matriptase Inhibitors

    PubMed Central

    2013-01-01

    Matriptase belongs to trypsin-like serine proteases involved in matrix remodeling/degradation, growth regulation, survival, motility, and cell morphogenesis. Herein, we report a structure-based approach, which led to the discovery of sulfonamide and amide derivatives of pyridyl bis(oxy)benzamidine as potent and selective matriptase inhibitors. Co-crystal structures of selected compounds in complex with matriptase supported compound designing. Additionally, WaterMap analyses indicated the possibility of occupying a distinct pocket within the catalytic domain, exploration of which resulted in >100-fold improvement in potency. Co-crystal structure of 10 with matriptase revealed critical interactions leading to potent target inhibition and selectivity against other serine proteases. PMID:24900621

  15. Discovery of a Highly Potent, Selective, and Orally Bioavailable Macrocyclic Inhibitor of Blood Coagulation Factor VIIa-Tissue Factor Complex.

    PubMed

    Zhang, Xiaojun; Glunz, Peter W; Johnson, James A; Jiang, Wen; Jacutin-Porte, Swanee; Ladziata, Vladimir; Zou, Yan; Phillips, Monique S; Wurtz, Nicholas R; Parkhurst, Brandon; Rendina, Alan R; Harper, Timothy M; Cheney, Daniel L; Luettgen, Joseph M; Wong, Pancras C; Seiffert, Dietmar; Wexler, Ruth R; Priestley, E Scott

    2016-08-11

    Inhibitors of the tissue factor (TF)/factor VIIa complex (TF-FVIIa) are promising novel anticoagulants which show excellent efficacy and minimal bleeding in preclinical models. Starting with an aminoisoquinoline P1-based macrocyclic inhibitor, optimization of the P' groups led to a series of highly potent and selective TF-FVIIa inhibitors which displayed poor permeability. Fluorination of the aminoisoquinoline reduced the basicity of the P1 group and significantly improved permeability. The resulting lead compound was highly potent, selective, and achieved good pharmacokinetics in dogs with oral dosing. Moreover, it demonstrated robust antithrombotic activity in a rabbit model of arterial thrombosis. PMID:27455395

  16. Use of Selective Inhibitors and Chromogenic Substrates to Differentiate Bacteria Based on Toluene Oxygenase Activity

    SciTech Connect

    Keener, William Kelvin; Schaller, Kastli Dianne; Walton, Michelle Rene; Partin, Judy Kaye; Watwood, Mary Elizabeth; Smith, William Aaron; Chingenpeel, S. R.

    2001-09-01

    In whole-cell studies, two alkynes, 1-pentyne and phenylacetylene, were selective, irreversible inhibitors of monooxygenase enzymes in catabolic pathways that permit growth of bacteria on toluene. 1-Pentyne selectively inhibited growth of Burkholderia cepacia G4 (toluene 2-monooxygenase [T2MO] pathway) and B. pickettii PKO1 (toluene 3-monooxygenase [T3MO] pathway) on toluene, but did not inhibit growth of bacteria expressing other pathways. In further studies with strain G4, chromogenic transformation of a,a,a-Trifluoro-m-cresol (TFC) was irreversibly inhibited by 1-pentyne, but the presence of phenol prevented this inhibition. Transformation of catechol by G4 was unaffected by 1-pentyne. With respect to the various pathways and bacteria tested, phenylacetylene selectively inhibited growth of Pseudomonas mendocina KR1 (toluene 4-monooxygenase [T4MO] pathway) on toluene, but not on p-cresol. An Escherichia coli transformant expressing T4MO transformed indole or naphthalene in chromogenic reactions, but not after exposure to phenylacetylene. The naphthalene reaction remained diminished in phenylacetylene-treated cells relative to untreated cells after phenylacetylene was removed, indicating irreversible inhibition. These techniques were used to differentiate toluene-degrading isolates from an aquifer. Based on data generated with these indicators and inhibitors, along with results from Biolog analysis for sole carbon source oxidation, the groundwater isolates were assigned to eight separate groups, some of which apparently differ in their mode of toluene catabolism.

  17. Identification of HCV protease inhibitor resistance mutations by selection pressure-based method

    PubMed Central

    Qiu, Ping; Sanfiorenzo, Vincent; Curry, Stephanie; Guo, Zhuyan; Liu, Shaotang; Skelton, Angela; Xia, Ellen; Cullen, Constance; Ralston, Robert; Greene, Jonathan; Tong, Xiao

    2009-01-01

    A major challenge to successful antiviral therapy is the emergence of drug-resistant viruses. Recent studies have developed several automated analyses of HIV sequence polymorphism based on calculations of selection pressure (Ka/Ks) to predict drug resistance mutations. Similar resistance analysis programs for HCV inhibitors are not currently available. Taking advantage of the recently available sequence data of patient HCV samples from a Phase II clinical study of protease inhibitor boceprevir, we calculated the selection pressure for all codons in the HCV protease region (amino acid 1–181) to identify potential resistance mutations. The correlation between mutations was also calculated to evaluate linkage between any two mutations. Using this approach, we identified previously known major resistant mutations, including a recently reported mutation V55A. In addition, a novel mutation V158I was identified, and we further confirmed its resistance to boceprevir in protease enzyme and replicon assay. We also extended the approach to analyze potential interactions between individual mutations and identified three pairs of correlated changes. Our data suggests that selection pressure-based analysis and correlation mapping could provide useful tools to analyze large amount of sequencing data from clinical samples and to identify new drug resistance mutations as well as their linkage and correlations. PMID:19395595

  18. Identification of HCV protease inhibitor resistance mutations by selection pressure-based method.

    PubMed

    Qiu, Ping; Sanfiorenzo, Vincent; Curry, Stephanie; Guo, Zhuyan; Liu, Shaotang; Skelton, Angela; Xia, Ellen; Cullen, Constance; Ralston, Robert; Greene, Jonathan; Tong, Xiao

    2009-06-01

    A major challenge to successful antiviral therapy is the emergence of drug-resistant viruses. Recent studies have developed several automated analyses of HIV sequence polymorphism based on calculations of selection pressure (K(a)/K(s)) to predict drug resistance mutations. Similar resistance analysis programs for HCV inhibitors are not currently available. Taking advantage of the recently available sequence data of patient HCV samples from a Phase II clinical study of protease inhibitor boceprevir, we calculated the selection pressure for all codons in the HCV protease region (amino acid 1-181) to identify potential resistance mutations. The correlation between mutations was also calculated to evaluate linkage between any two mutations. Using this approach, we identified previously known major resistant mutations, including a recently reported mutation V55A. In addition, a novel mutation V158I was identified, and we further confirmed its resistance to boceprevir in protease enzyme and replicon assay. We also extended the approach to analyze potential interactions between individual mutations and identified three pairs of correlated changes. Our data suggests that selection pressure-based analysis and correlation mapping could provide useful tools to analyze large amount of sequencing data from clinical samples and to identify new drug resistance mutations as well as their linkage and correlations. PMID:19395595

  19. Discovery of Highly Potent and Selective Inhibitors of Neuronal Nitric Oxide Synthase by Fragment Hopping

    PubMed Central

    Ji, Haitao; Li, Huiying; Martásek, Pavel; Roman, Linda J.; Poulos, Thomas L.; Silverman, Richard B.

    2009-01-01

    Selective inhibition of neuronal nitric oxide synthase (nNOS) has been shown to prevent brain injury and is important for the treatment of various neurodegenerative disorders. This study shows that not only greater inhibitory potency and isozyme selectivity, but more drug-like properties can be achieved by fragment hopping. Based on the structure of lead molecule 6, fragment hopping effectively extracted the minimal pharmacophoric elements in the active site of nNOS for ligand hydrophobic and steric interactions and generated appropriate lipophilic fragments for lead optimization. More potent and selective inhibitors with better drug-like properties were obtained within the design of 20 derivatives (compounds 7-26). Our structure-based inhibitor design for nNOS and SAR analysis reveal the robustness and efficiency of fragment hopping in lead discovery and structural optimization, which implicates a broad application of this approach to many other therapeutic targets for which known drug-like small-molecule modulators are still limited. PMID:19125620

  20. Crystal structure of PTP1B complexed with a potent and selective bidentate inhibitor.

    PubMed

    Sun, Jin-Peng; Fedorov, Alexander A; Lee, Seung-Yub; Guo, Xiao-Ling; Shen, Kui; Lawrence, David S; Almo, Steven C; Zhang, Zhong-Yin

    2003-04-01

    Protein-tyrosine phosphatase 1B (PTP1B) has been implicated as an important regulator in several signaling pathways including those initiated by insulin and leptin. Potent and specific PTP1B inhibitors could serve as useful tools in elucidating the physiological functions of PTP1B and may constitute valuable therapeutics in the treatment of several human diseases. We have determined the crystal structure of PTP1B in complex with compound 2, the most potent and selective PTP1B inhibitor reported to date. The structure at 2.15-A resolution reveals that compound 2 simultaneously binds to the active site and a unique proximal noncatalytic site formed by Lys-41, Arg-47, and Asp-48. The structural data are further corroborated by results from kinetic analyses of the interactions of PTP1B and its site-directed mutants with compound 2 and several of its variants. Although many of the residues important for interactions between PTP1B and compound 2 are not unique to PTP1B, the combinations of all contact residues differ between PTP isozymes, which provide a structural basis for potent and selective PTP1B inhibition. Our data further suggest that potent, yet highly selective, PTP1B inhibitory agents can be acquired by targeting the area defined by residues Lys-41, Arg-47, and Asp-48, in addition to the previously identified second aryl phosphate-binding pocket. PMID:12547827

  1. Anandamide transport is independent of fatty-acid amide hydrolase activity and is blocked by the hydrolysis-resistant inhibitor AM1172

    PubMed Central

    Fegley, D.; Kathuria, S.; Mercier, R.; Li, C.; Goutopoulos, A.; Makriyannis, A.; Piomelli, D.

    2004-01-01

    The endogenous cannabinoid anandamide is removed from the synaptic space by a high-affinity transport system present in neurons and astrocytes, which is inhibited by N-(4-hydroxyphenyl)-arachidonamide (AM404). After internalization, anandamide is hydrolyzed by fatty-acid amide hydrolase (FAAH), an intracellular membrane-bound enzyme that also cleaves AM404. Based on kinetic evidence, it has recently been suggested that anandamide internalization may be mediated by passive diffusion driven by FAAH activity. To test this possibility, in the present study, we have investigated anandamide internalization in wild-type and FAAH-deficient (FAAH–/–) mice. Cortical neurons from either mouse strain internalized [3H]anandamide through a similar mechanism, i.e., via a rapid temperature-sensitive and saturable process, which was blocked by AM404. Moreover, systemic administration of AM404 to either wild-type or FAAH–/– mice enhanced the hypothermic effects of exogenous anandamide, a response that was prevented by the CB1 cannabinoid antagonist rimonabant (SR141716A). The results indicate that anandamide internalization in mouse brain neurons is independent of FAAH activity. In further support of this conclusion, the compound N-(5Z, 8Z, 11Z, 14Z eicosatetraenyl)-4-hydroxybenzamide (AM1172) blocked [3H]anandamide internalization in rodent cortical neurons and human astrocytoma cells without acting as a FAAH substrate or inhibitor. AM1172 may serve as a prototype for novel anandamide transport inhibitors with increased metabolic stability. PMID:15138300

  2. Crystal Structure of Fatty Acid Amide Hydrolase Bound to the Carbamate Inhibitor URB597: Discovery of a Deacylating Water Molecule and Insight into Enzyme Inactivation

    SciTech Connect

    Mileni, Mauro; Kamtekar, Satwik; Wood, David C.; Benson, Timothy E.; Cravatt, Benjamin F.; Stevens, Raymond C.

    2010-08-12

    The endocannabinoid system regulates a wide range of physiological processes including pain, inflammation, and cognitive/emotional states. URB597 is one of the best characterized covalent inhibitors of the endocannabinoid-degrading enzyme fatty acid amide hydrolase (FAAH). Here, we report the structure of the FAAH-URB597 complex at 2.3 {angstrom} resolution. The structure provides insights into mechanistic details of enzyme inactivation and experimental evidence of a previously uncharacterized active site water molecule that likely is involved in substrate deacylation. This water molecule is part of an extensive hydrogen-bonding network and is coordinated indirectly to residues lining the cytosolic port of the enzyme. In order to corroborate our hypothesis concerning the role of this water molecule in FAAH's catalytic mechanism, we determined the structure of FAAH conjugated to a urea-based inhibitor, PF-3845, to a higher resolution (2.4 {angstrom}) than previously reported. The higher-resolution structure confirms the presence of the water molecule in a virtually identical location in the active site. Examination of the structures of serine hydrolases that are non-homologous to FAAH, such as elastase, trypsin, or chymotrypsin, shows a similarly positioned hydrolytic water molecule and suggests a functional convergence between the amidase signature enzymes and serine proteases.

  3. Selective inhibitors of nuclear export (SINE)--a novel class of anti-cancer agents.

    PubMed

    Parikh, Kaushal; Cang, Shundong; Sekhri, Arunabh; Liu, Delong

    2014-01-01

    Dysregulation of the nucleo-cytoplasmic transport of proteins plays an important role in carcinogenesis. The nuclear export of proteins depends on the activity of transport proteins, exportins. Exportins belong to the karyopherin β superfamily. Exportin-1 (XPO1), also known as chromosomal region maintenance 1 (CRM1), mediates transport of around 220 proteins. In this review, we summarized the development of a new class of antitumor drugs, collectively known as selective inhibitors of nuclear export (SINE). KPT-330 (selinexor) as an oral agent is showing activities in early clinical trials in both solid tumors and hematological malignancies. PMID:25316614

  4. Selective serotonin reuptake inhibitors and the risk for suicidality in adolescents: an update.

    PubMed

    Giner, Lucas; Nichols, C Matthew; Zalsman, Gil; Oquendo, Maria A

    2005-01-01

    The controversy regarding Selective Serotonin Reuptake Inhibitors (SSRIs) and suicidality dates back to the early 1990s. The first agent reported to be associated with suicidality was fluoxotine. In 2003, the British Medicines and Healthcare Products Regulatory Agency (MHRA) warned about possible risk of suicidality in children and adolescents treated with paroxetine for Major Depressive Disorder (MDD). This warning was soon extended to all the SSRIs as well as venlafaxine and mirtazapine. Similarly, the United States Food and Drug Administration (FDA) issued a "black box warning" on these medications in 2004. We address the debate concerning this warning and its clinical implications and review the latest contributions to the literature. PMID:16231472

  5. Discovery of the First Potent and Selective Inhibitors of Human dCTP Pyrophosphatase 1

    PubMed Central

    Jacques, Sylvain A.; Johansson, Lars; Calderón-Montaño, José Manuel; Claesson, Magnus; Loseva, Olga; Valerie, Nicholas C. K.; Lundbäck, Thomas; Piedrafita, Javier; Maga, Giovanni; Crespan, Emmanuele; Meijer, Laurent; Morón, Estefanía Burgos; Baranczewski, Pawel; Hagbjörk, Ann-Louise; Svensson, Richard; Wiita, Elisee; Almlöf, Ingrid; Visnes, Torkild; Jeppsson, Fredrik; Sigmundsson, Kristmundur; Jensen, Annika Jenmalm; Artursson, Per; Jemth, Ann-Sofie; Stenmark, Pål; Berglund, Ulrika Warpman; Scobie, Martin; Helleday, Thomas

    2016-01-01

    The dCTPase pyrophosphatase 1 (dCTPase) regulates the intracellular nucleotide pool through hydrolytic degradation of canonical and noncanonical nucleotide triphosphates (dNTPs). dCTPase is highly expressed in multiple carcinomas and is associated with cancer cell stemness. Here we report on the development of the first potent and selective dCTPase inhibitors that enhance the cytotoxic effect of cytidine analogues in leukemia cells. Boronate 30 displays a promising in vitro ADME profile, including plasma and mouse microsomal half-lives, aqueous solubility, cell permeability and CYP inhibition, deeming it a suitable compound for in vivo studies. PMID:26771665

  6. Identification of Potent, Selective, Cell-Active Inhibitors of the Histone Lysine Methyltransferase EZH2.

    PubMed

    Verma, Sharad K; Tian, Xinrong; LaFrance, Louis V; Duquenne, Céline; Suarez, Dominic P; Newlander, Kenneth A; Romeril, Stuart P; Burgess, Joelle L; Grant, Seth W; Brackley, James A; Graves, Alan P; Scherzer, Daryl A; Shu, Art; Thompson, Christine; Ott, Heidi M; Aller, Glenn S Van; Machutta, Carl A; Diaz, Elsie; Jiang, Yong; Johnson, Neil W; Knight, Steven D; Kruger, Ryan G; McCabe, Michael T; Dhanak, Dashyant; Tummino, Peter J; Creasy, Caretha L; Miller, William H

    2012-12-13

    The histone H3-lysine 27 (H3K27) methyltransferase EZH2 plays a critical role in regulating gene expression, and its aberrant activity is linked to the onset and progression of cancer. As part of a drug discovery program targeting EZH2, we have identified highly potent, selective, SAM-competitive, and cell-active EZH2 inhibitors, including GSK926 (3) and GSK343 (6). These compounds are small molecule chemical tools that would be useful to further explore the biology of EZH2. PMID:24900432

  7. Fragment-based drug discovery of potent and selective MKK3/6 inhibitors.

    PubMed

    Adams, Mark; Kobayashi, Toshitake; Lawson, J David; Saitoh, Morihisa; Shimokawa, Kenichiro; Bigi, Simone V; Hixon, Mark S; Smith, Christopher R; Tatamiya, Takayuki; Goto, Masayuki; Russo, Joseph; Grimshaw, Charles E; Swann, Steven

    2016-02-01

    The MAPK signaling cascade, comprised of several linear and intersecting pathways, propagates signaling into the nucleus resulting in cytokine and chemokine release. The Map Kinase Kinase isoforms 3 and 6 (MKK3 and MKK6) are responsible for the phosphorylation and activation of p38, and are hypothesized to play a key role in regulating this pathway without the redundancy seen in downstream effectors. Using FBDD, we have discovered efficient and selective inhibitors of MKK3 and MKK6 that can serve as tool molecules to help further understand the role of these kinases in MAPK signaling, and the potential impact of inhibiting kinases upstream of p38. PMID:26704264

  8. Design and Evaluation of 3-(Benzylthio)benzamide Derivatives as Potent and Selective SIRT2 Inhibitors

    PubMed Central

    2015-01-01

    Inhibitors of sirtuin-2 (SIRT2) deacetylase have been shown to be protective in various models of Huntington’s disease (HD) by decreasing polyglutamine aggregation, a hallmark of HD pathology. The present study was directed at optimizing the potency of SIRT2 inhibitors containing the 3-(benzylsulfonamido)benzamide scaffold and improving their metabolic stability. Molecular modeling and docking studies revealed an unfavorable role of the sulfonamide moiety for SIRT2 binding. This prompted us to replace the sulfonamide with thioether, sulfoxide, or sulfone groups. The thioether analogues were the most potent SIRT2 inhibitors with a two- to three-fold increase in potency relative to their corresponding sulfonamide analogues. The newly synthesized compounds also demonstrated higher SIRT2 selectivity over SIRT1 and SIRT3. Two thioether-derived compounds (17 and 18) increased α-tubulin acetylation in a dose-dependent manner in at least one neuronal cell line, and 18 was found to inhibit polyglutamine aggregation in PC12 cells. PMID:26005542

  9. Phospho-kinase profile of colorectal tumors guides in the selection of multi-kinase inhibitors

    PubMed Central

    Montero, Juan Carlos; Corrales-Sanchez, Verónica; Morales, Jorge Carlos; Núñez, Luz-Elena; Morís, Francisco; Pandiella, Atanasio; Ocaña, Alberto

    2015-01-01

    Protein kinases play a central role in the oncogenesis of colorectal tumors and are attractive druggable targets. Detection of activated kinases within a tumor could open avenues for drug selection and optimization of new kinase inhibitors. By using a phosphokinase arrays with human colorectal tumors we identified activated kinases, including the Epidermal Growth Factor Receptor (EGFR), components of the PI3K/mTOR pathway (AKT and S6), and STAT, among others. A pharmacological screening with kinase inhibitors against these proteins helped us to identify a new kinase inhibitor, termed EC-70124 that showed the highest anti-proliferative activity in cell lines. EC-70124 also inhibited cell migration and biochemical experiments demonstrated its effect targeting the PI3K/mTOR pathway. This drug also arrested cells at G2/M and induced apoptosis. Experiments in combination with standard chemotherapy used in the clinical setting indicated a synergistic effect. EC-70124 also reduced tumor growth in vivo and inhibited pS6 in the implanted tumors. In conclusion, by studying the kinase profile of colorectal tumors, we identified relevant activated pathways, and a new multi-kinase compound with significant antitumor properties. PMID:26418718

  10. Phospho-kinase profile of colorectal tumors guides in the selection of multi-kinase inhibitors.

    PubMed

    Serrano-Heras, Gemma; Cuenca-López, María Dolores; Montero, Juan Carlos; Corrales-Sanchez, Verónica; Morales, Jorge Carlos; Núñez, Luz-Elena; Morís, Francisco; Pandiella, Atanasio; Ocaña, Alberto

    2015-10-13

    Protein kinases play a central role in the oncogenesis of colorectal tumors and are attractive druggable targets. Detection of activated kinases within a tumor could open avenues for drug selection and optimization of new kinase inhibitors. By using a phosphokinase arrays with human colorectal tumors we identified activated kinases, including the Epidermal Growth Factor Receptor (EGFR), components of the PI3K/mTOR pathway (AKT and S6), and STAT, among others. A pharmacological screening with kinase inhibitors against these proteins helped us to identify a new kinase inhibitor, termed EC-70124 that showed the highest anti-proliferative activity in cell lines. EC-70124 also inhibited cell migration and biochemical experiments demonstrated its effect targeting the PI3K/mTOR pathway. This drug also arrested cells at G2/M and induced apoptosis. Experiments in combination with standard chemotherapy used in the clinical setting indicated a synergistic effect. EC-70124 also reduced tumor growth in vivo and inhibited pS6 in the implanted tumors. In conclusion, by studying the kinase profile of colorectal tumors, we identified relevant activated pathways, and a new multi-kinase compound with significant antitumor properties. PMID:26418718

  11. [Cyclooxygenase-2 (Cox-2) selective inhibitors: socioeconomic and pharmaco-epidemiologic aspects].

    PubMed

    Ruof, J; Hülsemann, J L

    2000-04-01

    Health authorities of several European countries recently introduced guidelines for socioeconomic evaluations. Additionally the activities of OMERACT (Outcome Measures in Rheumatoid Arthritis Clinical Trials) indicate an increasing awareness for the need of socioeconomic studies in rheumatology. The planned 2000 OMERACT meeting in Toulouse will address transfer of socioeconomic standards into rheumatology. In terms of cost effectiveness of selective Cox-2 inhibitors, a reference has to be made to the preceding discussion of cost effectiveness of Misoprostol. In addition, there are two models examining the cost effectiveness of Cox-2 inhibitors: a Canadian model comparing Nabumetone and Naproxen and an unpublished model assessing the cost effectiveness of Celecoxib (ACCES: Arthritis Cost Consequence Evaluation System). German data indicate that gastrointestinal bleedings account for 32.9% of all adverse drug events leading to a hospital admission. Further data assessing the morbidity due to adverse effects of nonsteroidal anti-inflammatory drugs are needed. Such data would allow the quantification of possible savings related to the usage of Cox-2 inhibitors in Germany. PMID:10868021

  12. Selective inhibitors of glutathione transferase P1 with trioxane structure as anticancer agents.

    PubMed

    Bräutigam, Maria; Teusch, Nicole; Schenk, Tobias; Sheikh, Miriam; Aricioglu, Rocky Z; Borowski, Swantje H; Neudörfl, Jörg-Martin; Baumann, Ulrich; Griesbeck, Axel G; Pietsch, Markus

    2015-04-01

    The response to chemotherapy in cancer patients is frequently compromised by drug resistance. Although chemoresistance is a multifactorial phenomenon, many studies have demonstrated that altered drug metabolism through the expression of phase II conjugating enzymes, including glutathione transferases (GSTs), in tumor cells can be directly correlated with resistance against a wide range of marketed anticancer drugs. In particular, overexpression of glutathione transferase P1 (GSTP1) appears to be a factor for poor prognosis during cancer therapy. Former and ongoing clinical trials have confirmed GSTP1 inhibition as a principle for antitumor therapy. A new series of 1,2,4-trioxane GSTP1 inhibitors were designed via a type II photooxygenation route of allylic alcohols followed by acid-catalyzed peroxyacetalization with aldehydes. A set of novel inhibitors exhibit low micromolar to high nanomolar inhibition of GSTP1, revealing preliminary SAR for further lead optimization. Importantly, high selectivity over another two human GST classes (GSTA1 and GSTM2) has been achieved. The trioxane GSTP1 inhibitors may therefore serve as a basis for the development of novel drug candidates in overcoming chemoresistance. PMID:25694385

  13. A Selective Small Molecule DNA2 Inhibitor for Sensitization of Human Cancer Cells to Chemotherapy

    PubMed Central

    Liu, Wenpeng; Zhou, Mian; Li, Zhengke; Li, Hongzhi; Polaczek, Piotr; Dai, Huifang; Wu, Qiong; Liu, Changwei; Karanja, Kenneth K.; Popuri, Vencat; Shan, Shu-ou; Schlacher, Katharina; Zheng, Li; Campbell, Judith L.; Shen, Binghui

    2016-01-01

    Cancer cells frequently up-regulate DNA replication and repair proteins such as the multifunctional DNA2 nuclease/helicase, counteracting DNA damage due to replication stress and promoting survival. Therefore, we hypothesized that blocking both DNA replication and repair by inhibiting the bifunctional DNA2 could be a potent strategy to sensitize cancer cells to stresses from radiation or chemotherapeutic agents. We show that homozygous deletion of DNA2 sensitizes cells to ionizing radiation and camptothecin (CPT). Using a virtual high throughput screen, we identify 4-hydroxy-8-nitroquinoline-3-carboxylic acid (C5) as an effective and selective inhibitor of DNA2. Mutagenesis and biochemical analysis define the C5 binding pocket at a DNA-binding motif that is shared by the nuclease and helicase activities, consistent with structural studies that suggest that DNA binding to the helicase domain is necessary for nuclease activity. C5 targets the known functions of DNA2 in vivo: C5 inhibits resection at stalled forks as well as reducing recombination. C5 is an even more potent inhibitor of restart of stalled DNA replication forks and over-resection of nascent DNA in cells defective in replication fork protection, including BRCA2 and BOD1L. C5 sensitizes cells to CPT and synergizes with PARP inhibitors. PMID:27211550

  14. CGX1037 is a novel PKC isoform delta selective inhibitor in platelets

    PubMed Central

    BHAVANASI, DHEERAJ; KOSTYAK, JOHN C.; SWINDLE, JOHN; KILPATRICK, LAURIE E.; KUNAPULI, SATYA P.

    2014-01-01

    Platelets upon activation change their shape, aggregate and secrete alpha and dense granule contents among which ADP acts as a feedback activator. Different Protein Kinase C (PKC) isoforms have specific non-redundant roles in mediating platelet responses including secretion and thrombus formation. Murine platelets lacking specific PKC isoforms have been used to evaluate the isoform specific functions. Novel PKC isoform δ has been shown to play an important role in some pathological processes. Lack of specific inhibitors for PKCδ has restricted analysis of its role in various cells. The current study was carried out to evaluate a novel small molecule PKCδ inhibitor, CGX1037 in platelets. Platelet aggregation, dense granule secretion and western blotting experiments were performed to evaluate CGX1037. In human platelets, CGX1037 inhibited PAR4-mediated phosphorylation on PKD2, a PKCδ-specific substrate. Pretreatment of human or murine platelets with CGX1037 inhibited PAR4-mediated dense granule secretion whereas it potentiated GPVI-mediated dense granule secretion similar to the responses observed in murine platelets lacking PKCδ Furthermore, pre-treatment of platelets from PKCδ−/− mice with CGX1037 had no significant additive effect on platelet responses suggesting the specificity of CGX1037. Hence, we show that CGX1037 is a selective small molecule inhibitor of PKCδ in platelets. PMID:24433221

  15. A Selective Small Molecule DNA2 Inhibitor for Sensitization of Human Cancer Cells to Chemotherapy.

    PubMed

    Liu, Wenpeng; Zhou, Mian; Li, Zhengke; Li, Hongzhi; Polaczek, Piotr; Dai, Huifang; Wu, Qiong; Liu, Changwei; Karanja, Kenneth K; Popuri, Vencat; Shan, Shu-Ou; Schlacher, Katharina; Zheng, Li; Campbell, Judith L; Shen, Binghui

    2016-04-01

    Cancer cells frequently up-regulate DNA replication and repair proteins such as the multifunctional DNA2 nuclease/helicase, counteracting DNA damage due to replication stress and promoting survival. Therefore, we hypothesized that blocking both DNA replication and repair by inhibiting the bifunctional DNA2 could be a potent strategy to sensitize cancer cells to stresses from radiation or chemotherapeutic agents. We show that homozygous deletion of DNA2 sensitizes cells to ionizing radiation and camptothecin (CPT). Using a virtual high throughput screen, we identify 4-hydroxy-8-nitroquinoline-3-carboxylic acid (C5) as an effective and selective inhibitor of DNA2. Mutagenesis and biochemical analysis define the C5 binding pocket at a DNA-binding motif that is shared by the nuclease and helicase activities, consistent with structural studies that suggest that DNA binding to the helicase domain is necessary for nuclease activity. C5 targets the known functions of DNA2 in vivo: C5 inhibits resection at stalled forks as well as reducing recombination. C5 is an even more potent inhibitor of restart of stalled DNA replication forks and over-resection of nascent DNA in cells defective in replication fork protection, including BRCA2 and BOD1L. C5 sensitizes cells to CPT and synergizes with PARP inhibitors. PMID:27211550

  16. Rational Design of Potent and Selective Inhibitors of an Epoxide Hydrolase Virulence Factor from Pseudomonas aeruginosa.

    PubMed

    Kitamura, Seiya; Hvorecny, Kelli L; Niu, Jun; Hammock, Bruce D; Madden, Dean R; Morisseau, Christophe

    2016-05-26

    The virulence factor cystic fibrosis transmembrane conductance regulator (CFTR) inhibitory factor (Cif) is secreted by Pseudomonas aeruginosa and is the founding member of a distinct class of epoxide hydrolases (EHs) that triggers the catalysis-dependent degradation of the CFTR. We describe here the development of a series of potent and selective Cif inhibitors by structure-based drug design. Initial screening revealed 1a (KB2115), a thyroid hormone analog, as a lead compound with low micromolar potency. Structural requirements for potency were systematically probed, and interactions between Cif and 1a were characterized by X-ray crystallography. On the basis of these data, new compounds were designed to yield additional hydrogen bonding with residues of the Cif active site. From this effort, three compounds were identified that are 10-fold more potent toward Cif than our first-generation inhibitors and have no detectable thyroid hormone-like activity. These inhibitors will be useful tools to study the pathological role of Cif and have the potential for clinical application. PMID:27120257

  17. Selective killing of G2 decatenation checkpoint defective colon cancer cells by catalytic topoisomerase II inhibitor.

    PubMed

    Jain, Chetan Kumar; Roychoudhury, Susanta; Majumder, Hemanta Kumar

    2015-05-01

    Cancer cells with defective DNA decatenation checkpoint can be selectively targeted by the catalytic inhibitors of DNA topoisomerase IIα (topo IIα) enzyme. Upon treatment with catalytic topo IIα inhibitors, cells with defective decatenation checkpoint fail to arrest their cell cycle in G2 phase and enter into M phase with catenated and under-condensed chromosomes resulting into impaired mitosis and eventually cell death. In the present work we analyzed decatenation checkpoint in five different colon cancer cell lines (HCT116, HT-29, Caco2, COLO 205 and SW480) and in one non-cancerous cell line (HEK293T). Four out of the five colon cancer cell lines i.e. HCT116, HT-29, Caco2, and COLO 205 were found to be compromised for the decatenation checkpoint function at different extents, whereas SW480 and HEK293T cell lines were found to be proficient for the checkpoint function. Upon treatment with ICRF193, decatenation checkpoint defective cell lines failed to arrest the cell cycle in G2 phase and entered into M phase without proper chromosomal decatenation, resulting into the formation of tangled mass of catenated and under-condensed chromosomes. Such cells underwent mitotic catastrophe and rapid apoptosis like cell death and showed higher sensitivity for ICRF193. Our study suggests that catalytic inhibitors of topoisomerase IIα are promising therapeutic agents for the treatment of colon cancers with defective DNA decatenation checkpoint. PMID:25746763

  18. Δ9-Tetrahydrocannabinol and Endocannabinoid Degradative Enzyme Inhibitors Attenuate Intracranial Self-Stimulation in Mice

    PubMed Central

    Grim, Travis W.; Owens, Robert A.; Lazenka, Matthew F.; Sim-Selley, Laura J.; Abdullah, Rehab A.; Niphakis, Micah J.; Vann, Robert E.; Cravatt, Benjamin F.; Wiley, Jenny L.; Negus, S. Stevens; Lichtman, Aron H.

    2015-01-01

    A growing body of evidence implicates endogenous cannabinoids as modulators of the mesolimbic dopamine system and motivated behavior. Paradoxically, the reinforcing effects of Δ9-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis, have been difficult to detect in preclinical rodent models. In this study, we investigated the impact of THC and inhibitors of the endocannabinoid hydrolytic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on operant responding for electrical stimulation of the medial forebrain bundle [intracranial self-stimulation (ICSS)], which is known to activate the mesolimbic dopamine system. These drugs were also tested in assays of operant responding for food reinforcement and spontaneous locomotor activity. THC and the MAGL inhibitor JZL184 (4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) attenuated operant responding for ICSS and food, and also reduced spontaneous locomotor activity. In contrast, the FAAH inhibitor PF-3845 (N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) was largely without effect in these assays. Consistent with previous studies showing that combined inhibition of FAAH and MAGL produces a substantially greater cannabimimetic profile than single enzyme inhibition, the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) produced a similar magnitude of ICSS depression as that produced by THC. ICSS attenuation by JZL184 was associated with increased brain levels of 2-arachidonoylglycerol (2-AG), whereas peak effects of SA-57 were associated with increased levels of both N-arachidonoylethanolamine (anandamide) and 2-AG. The cannabinoid receptor type 1 receptor antagonist rimonabant, but not the cannabinoid receptor type 2 receptor antagonist SR144528, blocked the attenuating effects of THC, JZL184, and SA-57 on ICSS

  19. Δ9-tetrahydrocannabinol and endocannabinoid degradative enzyme inhibitors attenuate intracranial self-stimulation in mice.

    PubMed

    Wiebelhaus, Jason M; Grim, Travis W; Owens, Robert A; Lazenka, Matthew F; Sim-Selley, Laura J; Abdullah, Rehab A; Niphakis, Micah J; Vann, Robert E; Cravatt, Benjamin F; Wiley, Jenny L; Negus, S Stevens; Lichtman, Aron H

    2015-02-01

    A growing body of evidence implicates endogenous cannabinoids as modulators of the mesolimbic dopamine system and motivated behavior. Paradoxically, the reinforcing effects of Δ(9)-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis, have been difficult to detect in preclinical rodent models. In this study, we investigated the impact of THC and inhibitors of the endocannabinoid hydrolytic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on operant responding for electrical stimulation of the medial forebrain bundle [intracranial self-stimulation (ICSS)], which is known to activate the mesolimbic dopamine system. These drugs were also tested in assays of operant responding for food reinforcement and spontaneous locomotor activity. THC and the MAGL inhibitor JZL184 (4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) attenuated operant responding for ICSS and food, and also reduced spontaneous locomotor activity. In contrast, the FAAH inhibitor PF-3845 (N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) was largely without effect in these assays. Consistent with previous studies showing that combined inhibition of FAAH and MAGL produces a substantially greater cannabimimetic profile than single enzyme inhibition, the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) produced a similar magnitude of ICSS depression as that produced by THC. ICSS attenuation by JZL184 was associated with increased brain levels of 2-arachidonoylglycerol (2-AG), whereas peak effects of SA-57 were associated with increased levels of both N-arachidonoylethanolamine (anandamide) and 2-AG. The cannabinoid receptor type 1 receptor antagonist rimonabant, but not the cannabinoid receptor type 2 receptor antagonist SR144528, blocked the attenuating effects of THC, JZL184, and SA-57 on

  20. Hydroxyquinoline-derived compounds and analoguing of selective MCL-1 inhibitors using a functional biomarker

    PubMed Central

    Richard, David J.; Lena, Ryan; Bannister, Thomas; Blake, Noel; Pierceall, William E.; Carlson, Nicole E.; Keller, Christina Eberhart; Koenig, Marcel; He, Yuanjun; Minond, Dmitriy; Mishra, Jitendra; Cameron, Michael; Spicer, Timothy; Hodder, Peter; Cardone, Michael H.

    2013-01-01

    Anti-apoptotic Bcl-2 family proteins are important oncology therapeutic targets. To date, BH3 mimetics that abrogate anti-apoptotic activity have largely been directed at Bcl-2 and/or Bcl-xL. One observed mechanism of resistance to these inhibitors is increased Mcl-1 levels in cells exposed to such therapeutics. For this reason, and because Mcl-1 is important in the onset of lymphoid, myeloid, and other cancers, it has become a target of great interest. However, small molecule inhibitors displaying potency and selectivity for Mcl-1 are lacking. Identifying such compounds has been challenging due to difficulties in translating the target selectivity observed at the biochemical level to the cellular level. Herein we report the results of an HTS strategy coupled with directed hit optimization. Compounds identified have selective Mcl-1 inhibitory activity with greater than 100-fold reduced affinity for Bcl-xL. The selectivity of these compounds at the cellular level was validated using BH3 profiling, a novel personalized diagnostic approach. This assay provides an important functional biomarker that allows for the characterization of cells based upon their dependencies on various anti-apoptotic Bcl-2 proteins. We demonstrate that cells dependent on Mcl-1 or Bcl-2/Bcl-xL for survival are commensurately responsive to compounds that genuinely target those proteins. The identification of compound 9 with uniquely validated and selective Mcl-1 inhibitory activity provides a valuable tool to those studying the intrinsic apoptosis pathway and highlights an important approach in the development of a first-in-class cancer therapeutic. PMID:23993674

  1. Discovery of Cyclic Acylguanidines as Highly Potent and Selective β-Site Amyloid Cleaving Enzyme (BACE) Inhibitors: Part I–Inhibitor Design and Validation

    SciTech Connect

    Zhu, Zhaoning; Sun, Zhong-Yue; Ye, Yuanzan; Voigt, Johannes; Strickland, Corey; Smith, Elizabeth M.; Cumming, Jared; Wang, Lingyan; Wong, Jesse; Wang, Yu-Sen; Wyss, Daniel F.; Chen, Xia; Kuvelkar, Reshma; Kennedy, Matthew E.; Favreau, Leonard; Parker, Eric; McKittrick, Brian A.; Stamford, Andrew; Czarniecki, Michael; Greenlee, William; Hunter, John C.

    2013-11-20

    A number of novel amidine containing heterocycles were designed to reproduce the unique interaction pattern, revealed by X-ray crystallography, between the BACE-1 catalytic diad and a weak NMR screening hit, with special attention paid to maintaining the appropriate basicity and limiting the number of H-bonding donors of these scaffolds. The iminohydantoin cores were examined first and found to interact with the catalytic diad in one of two binding modes (A and B), each with the iminohydantoin core flipped 180° in relation to the other. The amidine structural motif within each core forms a bidentate interaction with a different aspartic acid of the catalytic diad. Both modes reproduced a highly conserved interaction pattern between the inhibitors and the catalytic aspartates. Potent iminohydantoin BACE-1 inhibitors have been obtained, validating the molecular design as aspartyl protease catalytic site inhibitors. Brain penetrant small molecule BACE inhibitors with high ligand efficiencies have been discovered, enabling multiple strategies for further development of these inhibitors into highly potent, selective and in vivo efficacious BACE inhibitors.

  2. Discovery of Cyclic Acylguanidines as Highly Potent and Selective β-Site Amyloid Cleaving Enzyme (BACE) Inhibitors: Part I-Inhibitor Design and Validation

    SciTech Connect

    Zhu, Zhaoning; Sun, Zhong-Yue; Ye, Yuanzan; Voigt, Johannes; Strickland, Corey; Smith, Elizabeth M; Cumming, Jared; Wang, Lingyan; Wong, Jesse; Wang, Yu-Sen; Wyss, Daniel F; Chen, Xia; Kuvelkar, Reshma; Kennedy, Matthew E; Favreau, Leonard; Parker, Eric; McKittrick, Brian A; Stamford, Andrew; Czarniecki, Michael; Greenlee, William; Hunter, John C

    2010-10-18

    A number of novel amidine containing heterocycles were designed to reproduce the unique interaction pattern, revealed by X-ray crystallography, between the BACE-1 catalytic diad and a weak NMR screening hit (3), with special attention paid to maintaining the appropriate basicity and limiting the number of H-bonding donors of these scaffolds. The iminohydantoin cores (10 and 23) were examined first and found to interact with the catalytic diad in one of two binding modes (A and B), each with the iminohydantoin core flipped 180º in relation to the other. The amidine structural motif within each core forms a bidentate interaction with a different aspartic acid of the catalytic diad. Both modes reproduced a highly conserved interaction pattern between the inhibitors and the catalytic aspartates, as revealed by 3. Potent iminohydantoin BACE-1 inhibitors have been obtained, validating the molecular design as aspartyl protease catalytic site inhibitors. Brain penetrant small molecule BACE inhibitors with high ligand efficiencies have been discovered, enabling multiple strategies for further development of these inhibitors into highly potent, selective and in vivo efficacious BACE inhibitors.

  3. Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

    SciTech Connect

    Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M.

    2014-10-02

    Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

  4. Discovery of pyrazole as C-terminus of selective BACE1 inhibitors.

    PubMed

    Zou, Yiquan; Xu, Lei; Chen, Wuyan; Zhu, Yiping; Chen, Tiantian; Fu, Yan; Li, Li; Ma, Lanping; Xiong, Bing; Wang, Xin; Li, Jian; He, Jianhua; Zhang, Haiyan; Xu, Yechun; Li, Jia; Shen, Jingkang

    2013-10-01

    We recently discovered and reported dual inhibitor 5 of AChE and BACE1 with N-benzylpiperidine ethyl as C-terminus. Compound 5 showed potent inhibitory activities for BACE1, and could reduce endogenous Aβ1-40 production in APP transgenic mice. In present work, we rapidly identified substituted triazole as the C-terminus of compound 5 by replacing the benzylpiperidine ethyl group with click chemistry and tested these synthesized compounds by in situ screening assay. As revealed by the crystal structures of BACE1 in complex with our triazole compound 12, we found that Pro70 and Thr72 located in the flap region were the critical components for binding with these inhibitors. With the aid of the crystal structure, a new series of five-membered heterocyclic compounds was prepared in order to explore the structure-activity relationship (SAR) of this class of molecules. From these efforts, pyrazole was discovered as a novel C-terminus of BACE1 inhibitors. After further modification of pyrazole with variable substituents, compound 37 exhibited good potency in enzyme inhibition assay (IC50=0.025 μM) and compound 33 showed moderate inhibition effects on Aβ production of APP transfected HEK293 cells. Moreover, these pyrazole derivatives demonstrated good selectivity versus cathepsin D. Our results indicated that the vicinity of Pro70 and Thr72 might be utilized as a subsite, and the discovered pyrazole derivatives might provide useful hints for developing novel BACE1 inhibitors as anti-AD drugs. PMID:23988410

  5. Selective serotonin reuptake inhibitors and theophylline metabolism in human liver microsomes: potent inhibition by fluvoxamine.

    PubMed Central

    Rasmussen, B B; Maënpää, J; Pelkonen, O; Loft, S; Poulsen, H E; Lykkesfeldt, J; Brøsen, K

    1995-01-01

    1. Fluvoxamine and seven other selective serotonin reuptake inhibitors (SRRI) were tested for their ability to inhibit a number of human cytochrome P450 isoforms (CYPs). 2. None of the drugs showed potent inhibition of CYP2A6 (coumarin 7-hydroxylase) or CYP2E1 (chlorzoxazone 6-hydroxylase), while norfluoxetine was the only potent inhibitor of CYP3A having IC50 values of 11 microM and 19 microM for testosterone 6 beta-hydroxylase and cortisol 6 beta-hydroxylase, respectively. 3. Norfluoxetine, sertraline and fluvoxamine inhibited CYP1A1 (7-ethoxyresorufin O-deethylase) in microsomes from human placenta (IC50 values 29 microM, 35 microM and 80 microM, respectively). Fluvoxamine was a potent inhibitor of CYP1A2-mediated 7-ethoxyresorufin O-deethylase activity (IC50 = 0.3 microM) in human liver. 4. In microsomes from three human livers fluvoxamine potently inhibited all pathways of theophylline biotransformation, the apparent inhibitor constant, Ki, was 0.07-0.13 microM, 0.05-0.10 microM and 0.16-0.29 microM for inhibition of 1-methylxanthine, 3-methylxanthine and 1,3-dimethyluric acid formation, respectively. Seven other SSRIs showed either weak or no inhibition of theophylline metabolism. 5. Ethanol inhibited the formation of 1,3-dimethyluric acid with K(i) value of 300 microM, a value which is consistent with inhibition of CYP2E1. Ethanol and fluvoxamine both inhibited 8-hydroxylation by about 45% and, in combination, the compounds decreased the formation of 1,3-dimethyluric acid by 90%, indicating that CYP1A2 and CYP2E1 are equally important isoforms for the 8-hydroxylation of theophylline. 6. It is concluded that pharmacokinetic interaction between fluvoxamine and theophylline is due to potent inhibition of CYP1A2. PMID:7742153

  6. A novel cofactor-binding mode in bacterial IMP dehydrogenases explains inhibitor selectivity

    SciTech Connect

    Makowska-Grzyska, Magdalena; Kim, Youngchang; Maltseva, Natalia; Osipiuk, Jerzy; Gu, Minyi; Zhang, Minjia; Mandapati, Kavitha; Gollapalli, Deviprasad R.; Gorla, Suresh Kumar; Hedstrom, Lizbeth; Joachimiak, Andrzej

    2015-01-09

    The steadily rising frequency of emerging diseases and antibiotic resistance creates an urgent need for new drugs and targets. Inosine 5'-monophosphate dehydrogenase (IMP dehydrogenase or IMPDH) is a promising target for the development of new antimicrobial agents. IMPDH catalyzes the oxidation of IMP to XMP with the concomitant reduction of NAD+, which is the pivotal step in the biosynthesis of guanine nucleotides. Potent inhibitors of bacterial IMPDHs have been identified that bind in a structurally distinct pocket that is absent in eukaryotic IMPDHs. The physiological role of this pocket was not understood. Here, we report the structures of complexes with different classes of inhibitors of Bacillus anthracis, Campylobacter jejuni, and Clostridium perfringens IMPDHs. These structures in combination with inhibition studies provide important insights into the interactions that modulate selectivity and potency. We also present two structures of the Vibrio cholerae IMPDH in complex with IMP/NAD+ and XMP/NAD+. In both structures, the cofactor assumes a dramatically different conformation than reported previously for eukaryotic IMPDHs and other dehydrogenases, with the major change observed for the position of the NAD+ adenosine moiety. More importantly, this new NAD+-binding site involves the same pocket that is utilized by the inhibitors. Thus, the bacterial IMPDH-specific NAD+-binding mode helps to rationalize the conformation adopted by several classes of prokaryotic IMPDH inhibitors. As a result, these findings offer a potential strategy for further ligand optimization.

  7. Moguntinones--new selective inhibitors for the treatment of human colorectal cancer.

    PubMed

    Maderer, Annett; Plutizki, Stanislav; Kramb, Jan-Peter; Göpfert, Katrin; Linnig, Monika; Khillimberger, Katrin; Ganser, Christopher; Lauermann, Eva; Dannhardt, Gerd; Galle, Peter R; Moehler, Markus

    2014-06-01

    3-Indolyl and 3-azaindolyl-4-aryl maleimide derivatives, called moguntinones (MOG), have been selected for their ability to inhibit protein kinases associated with angiogenesis and induce apoptosis. Here, we characterize their mode of action and their potential clinical value in human colorectal cancer in vitro and in vivo. MOG-19 and MOG-13 were characterized in vitro using kinase, viability, and apoptosis assays in different human colon cancer (HT-29, HCT-116, Caco-2, and SW480) and normal colon cell lines (CCD-18Co, FHC, and HCoEpiC) alone or in combination with topoisomerase I inhibitors. Intracellular signaling pathways were analyzed by Western blotting. To determine their potential to inhibit tumor growth in vivo, the human HT-29 tumor xenograft model was used. Moguntinones prominently inhibit several protein kinases associated with tumor growth and metastasis. Specific signaling pathways such as GSK3β and mTOR downstream targets were inhibited with IC(50) values in the nanomolar range. GSK3β signaling inhibition was independent of KRAS, BRAF, and PI3KCA mutation status. While moguntinones alone induced apoptosis only in concentrations >10 μmol/L, MOG-19 in combination with topoisomerase I inhibitors induced apoptosis synergistically at lower concentrations. Consistent with in vitro data, MOG-19 significantly reduced tumor volume and weight in combination with a topoisomerase I inhibitor in vivo. Our in vitro and in vivo data present significant proapoptotic, antiangiogenic, and antiproliferative effects of MOG-19 in different human colon cancer cells. Combination with clinically relevant topoisomerase I inhibitors in vitro and xenograft mouse model demonstrate a high potency of moguntinones to complement and improve standard chemotherapy options in human colorectal cancer. PMID:24743703

  8. Synthesis and biochemical evaluation of benzoylbenzophenone thiosemicarbazone analogues as potent and selective inhibitors of cathepsin L.

    PubMed

    Parker, Erica N; Song, Jiangli; Kishore Kumar, G D; Odutola, Samuel O; Chavarria, Gustavo E; Charlton-Sevcik, Amanda K; Strecker, Tracy E; Barnes, Ashleigh L; Sudhan, Dhivya R; Wittenborn, Thomas R; Siemann, Dietmar W; Horsman, Michael R; Chaplin, David J; Trawick, Mary Lynn; Pinney, Kevin G

    2015-11-01

    Upregulation of cathepsin L in a variety of tumors and its ability to promote cancer cell invasion and migration through degradation of the extracellular matrix suggest that cathepsin L is a promising biological target for the development of anti-metastatic agents. Based on encouraging results from studies on benzophenone thiosemicarbazone cathepsin inhibitors, a series of fourteen benzoylbenzophenone thiosemicarbazone analogues were designed, synthesized, and evaluated for their inhibitory activity against cathepsins L and B. Thiosemicarbazone inhibitors 3-benzoylbenzophenone thiosemicarbazone 1, 1,3-bis(4-fluorobenzoyl)benzene thiosemicarbazone 8, and 1,3-bis(2-fluorobenzoyl)-5-bromobenzene thiosemicarbazone 32 displayed the greatest potency against cathepsin L with low IC50 values of 9.9 nM, 14.4 nM, and 8.1 nM, respectively. The benzoylbenzophenone thiosemicarbazone analogues evaluated were selective in their inhibition of cathepsin L compared to cathepsin B. Thiosemicarbazone analogue 32 inhibited invasion through Matrigel of MDA-MB-231 breast cancer cells by 70% at 10 μM. Thiosemicarbazone analogue 8 significantly inhibited the invasive potential of PC-3ML prostate cancer cells by 92% at 5 μM. The most active cathepsin L inhibitors from this benzoylbenzophenone thiosemicarbazone series (1, 8, and 32) displayed low cytotoxicity toward normal primary cells [in this case human umbilical vein endothelial cells (HUVECs)]. In an initial in vivo study, 3-benzoylbenzophenone thiosemicarbazone (1) was well-tolerated in a CDF1 mouse model bearing an implanted C3H mammary carcinoma, and showed efficacy in tumor growth delay. Low cytotoxicity, inhibition of cell invasion, and in vivo tolerability are desirable characteristics for anti-metastatic agents functioning through an inhibition of cathepsin L. Active members of this structurally diverse group of benzoylbenzophenone thiosemicarbazone cathepsin L inhibitors show promise as potential anti-metastatic, pre

  9. A Double Whammy: Targeting Both Fatty Acid Amide Hydrolase (FAAH) and Cyclooxygenase (COX) To Treat Pain and Inflammation.

    PubMed

    Scarpelli, Rita; Sasso, Oscar; Piomelli, Daniele

    2016-06-20

    Pain states that arise from non-resolving inflammation, such as inflammatory bowel disease or arthritis, pose an unusually difficult challenge for therapy because of the complexity and heterogeneity of their underlying mechanisms. It has been suggested that key nodes linking interactive pathogenic pathways of non-resolving inflammation might offer novel targets for the treatment of inflammatory pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit the cyclooxygenase (COX)-mediated production of pain- and inflammation-inducing prostanoids, are a common first-line treatment for this condition, but their use is limited by mechanism-based side effects. The endogenous levels of anandamide, an endocannabinoid mediator with analgesic and tissue-protective functions, are regulated by fatty acid amide hydrolase (FAAH). This review outlines the pharmacological and chemical rationale for the simultaneous inhibition of COX and FAAH activities with designed multitarget agents. Preclinical studies indicate that such agents may combine superior anti-inflammatory efficacy with reduced toxicity. PMID:26486424

  10. Selective AKR1C3 inhibitors do not recapitulate the anti-leukaemic activities of the pan-AKR1C inhibitor medroxyprogesterone acetate

    PubMed Central

    Khanim, F; Davies, N; Veliça, P; Hayden, R; Ride, J; Pararasa, C; Chong, M G; Gunther, U; Veerapen, N; Winn, P; Farmer, R; Trivier, E; Rigoreau, L; Drayson, M; Bunce, C

    2014-01-01

    Background: We and others have identified the aldo-keto reductase AKR1C3 as a potential drug target in prostate cancer, breast cancer and leukaemia. As a consequence, significant effort is being invested in the development of AKR1C3-selective inhibitors. Methods: We report the screening of an in-house drug library to identify known drugs that selectively inhibit AKR1C3 over the closely related isoforms AKR1C1, 1C2 and 1C4. This screen initially identified tetracycline as a potential AKR1C3-selective inhibitor. However, mass spectrometry and nuclear magnetic resonance studies identified that the active agent was a novel breakdown product (4-methyl(de-dimethylamine)-tetracycline (4-MDDT)). Results: We demonstrate that, although 4-MDDT enters AML cells and inhibits their AKR1C3 activity, it does not recapitulate the anti-leukaemic actions of the pan-AKR1C inhibitor medroxyprogesterone acetate (MPA). Screens of the NCI diversity set and an independently curated small-molecule library identified several additional AKR1C3-selective inhibitors, none of which had the expected anti-leukaemic activity. However, a pan AKR1C, also identified in the NCI diversity set faithfully recapitulated the actions of MPA. Conclusions: In summary, we have identified a novel tetracycline-derived product that provides an excellent lead structure with proven drug-like qualities for the development of AKR1C3 inhibitors. However, our findings suggest that, at least in leukaemia, selective inhibition of AKR1C3 is insufficient to elicit an anticancer effect and that multiple AKR1C inhibition may be required. PMID:24569460

  11. A calpain-2 selective inhibitor enhances learning & memory by prolonging ERK activation.

    PubMed

    Liu, Yan; Wang, Yubin; Zhu, Guoqi; Sun, Jiandong; Bi, Xiaoning; Baudry, Michel

    2016-06-01

    While calpain-1 activation is required for LTP induction by theta burst stimulation (TBS), calpain-2 activation limits its magnitude during the consolidation period. A selective calpain-2 inhibitor applied either before or shortly after TBS enhanced the degree of potentiation. In the present study, we tested whether the selective calpain-2 inhibitor, Z-Leu-Abu-CONH-CH2-C6H3 (3, 5-(OMe)2 (C2I), could enhance learning and memory in wild-type (WT) and calpain-1 knock-out (C1KO) mice. We first showed that C2I could reestablish TBS-LTP in hippocampal slices from C1KO mice, and this effect was blocked by PD98059, an inhibitor of ERK. TBS resulted in PTEN degradation in hippocampal slices from both WT and C1KO mice, and C2I treatment blocked this effect in both mouse genotypes. Systemic injection of C2I 30 min before training in the fear-conditioning paradigm resulted in a biphasic dose-response curve, with low doses enhancing and high doses inhibiting freezing behavior. The difference between the doses needed to enhance and inhibit learning matches the difference in concentrations producing inhibition of calpain-2 and calpain-1. A low dose of C2I also restored normal learning in a novel object recognition task in C1KO mice. Levels of SCOP, a ERK phosphatase known to be cleaved by calpain-1, were decreased in dorsal hippocampus early but not late following training in WT mice; C2I treatment did not affect the early decrease in SCOP levels but prevented its recovery at the later time-point and prolonged ERK activation. The results indicate that calpain-2 activation limits the extent of learning, an effect possibly due to temporal limitation of ERK activation, as a result of SCOP synthesis induced by calpain-2-mediated PTEN degradation. PMID:26907807

  12. A Potent, Selective, and Cell-Active Inhibitor of Human Type I Protein Arginine Methyltransferases.

    PubMed

    Eram, Mohammad S; Shen, Yudao; Szewczyk, Magdalena M; Wu, Hong; Senisterra, Guillermo; Li, Fengling; Butler, Kyle V; Kaniskan, H Ümit; Speed, Brandon A; dela Seña, Carlo; Dong, Aiping; Zeng, Hong; Schapira, Matthieu; Brown, Peter J; Arrowsmith, Cheryl H; Barsyte-Lovejoy, Dalia; Liu, Jing; Vedadi, Masoud; Jin, Jian

    2016-03-18

    Protein arginine methyltransferases (PRMTs) play a crucial role in a variety of biological processes. Overexpression of PRMTs has been implicated in various human diseases including cancer. Consequently, selective small-molecule inhibitors of PRMTs have been pursued by both academia and the pharmaceutical industry as chemical tools for testing biological and therapeutic hypotheses. PRMTs are divided into three categories: type I PRMTs which catalyze mono- and asymmetric dimethylation of arginine residues, type II PRMTs which catalyze mono- and symmetric dimethylation of arginine residues, and type III PRMT which catalyzes only monomethylation of arginine residues. Here, we report the discovery of a potent, selective, and cell-active inhibitor of human type I PRMTs, MS023, and characterization of this inhibitor in a battery of biochemical, biophysical, and cellular assays. MS023 displayed high potency for type I PRMTs including PRMT1, -3, -4, -6, and -8 but was completely inactive against type II and type III PRMTs, protein lysine methyltransferases and DNA methyltransferases. A crystal structure of PRMT6 in complex with MS023 revealed that MS023 binds the substrate binding site. MS023 potently decreased cellular levels of histone arginine asymmetric dimethylation. It also reduced global levels of arginine asymmetric dimethylation and concurrently increased levels of arginine monomethylation and symmetric dimethylation in cells. We also developed MS094, a close analog of MS023, which was inactive in biochemical and cellular assays, as a negative control for chemical biology studies. MS023 and MS094 are useful chemical tools for investigating the role of type I PRMTs in health and disease. PMID:26598975

  13. The effects of siguazodan, a selective phosphodiesterase inhibitor, on human platelet function.

    PubMed Central

    Murray, K. J.; England, P. J.; Hallam, T. J.; Maguire, J.; Moores, K.; Reeves, M. L.; Simpson, A. W.; Rink, T. J.

    1990-01-01

    1. The effects of siguazodan (SK&F 94836) a selective phosphodiesterase (PDE) inhibitor with inotropic and vasodilator activity, were studied on human platelets. 2. Siguazodan selectively inhibited the major cyclic AMP-hydrolysing PDE in human platelet supernatants. The inhibited enzyme has been variously termed cyclic GMP-inhibited PDE or PDE-III. 3. In platelet-rich plasma (PRP), siguazodan inhibited U46619-induced aggregation more potently than that induced by ADP and collagen. Treatment of the PRP with aspirin had no effect on the potency of siguazodan. 4. In washed platelets, siguazodan increased cyclic AMP levels and reduced cytoplasmic free calcium [( Ca2+]i). ADP decreased the ability of siguazodan to raise cyclic AMP and this may explain its lower potency in inhibiting responses to ADP. 5. Siguazodan has anti-platelet actions over the same concentration range that it is an inotrope and vasodilator. PMID:2158847

  14. Synthesis and biological evaluation of novel FK228 analogues as potential isoform selective HDAC inhibitors.

    PubMed

    Narita, Koichi; Matsuhara, Keisuke; Itoh, Jun; Akiyama, Yui; Dan, Singo; Yamori, Takao; Ito, Akihiro; Yoshida, Minoru; Katoh, Tadashi

    2016-10-01

    Novel C4- and C7-modified FK228 analogues were efficiently synthesized in a highly convergent and unified manner. This synthesis features the amide condensation of glycine-d-cysteine-containing segments with d-valine-containing segments for the direct assembly of the corresponding seco-acids, which are key precursors of macrolactones. The HDAC inhibition assay and cell-growth inhibition analysis of the synthesized analogues revealed novel aspects of their structure-activity relationship. This study demonstrated that simple modification at the C4 and C7 side chains in FK228 is effective for improving both HDAC inhibitory activity and isoform selectivity; moreover, potent and highly isoform-selective class I HDAC1 inhibitors were identified. PMID:27318982

  15. Novel selective and potent inhibitors of malaria parasite dihydroorotate dehydrogenase: discovery and optimization of dihydrothiophenone derivatives.

    PubMed

    Xu, Minghao; Zhu, Junsheng; Diao, Yanyan; Zhou, Hongchang; Ren, Xiaoli; Sun, Deheng; Huang, Jin; Han, Dongmei; Zhao, Zhenjiang; Zhu, Lili; Xu, Yufang; Li, Honglin

    2013-10-24

    Taking the emergence of drug resistance and lack of effective antimalarial vaccines into consideration, it is of significant importance to develop novel antimalarial agents for the treatment of malaria. Herein, we elucidated the discovery and structure-activity relationships of a series of dihydrothiophenone derivatives as novel specific inhibitors of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH). The most promising compound, 50, selectively inhibited PfDHODH (IC50 = 6 nM, with >14,000-fold species-selectivity over hDHODH) and parasite growth in vitro (IC50 = 15 and 18 nM against 3D7 and Dd2 cells, respectively). Moreover, an oral bioavailability of 40% for compound 50 was determined from in vivo pharmacokinetic studies. These results further indicate that PfDHODH is an effective target for antimalarial chemotherapy, and the novel scaffolds reported in this work might lead to the discovery of new antimalarial agents. PMID:24073986

  16. N-(3-Ethynyl-2,4-difluorophenyl)sulfonamide Derivatives as Selective Raf Inhibitors

    PubMed Central

    2015-01-01

    A series of N-(3-ethynyl-2,4-difluorophenyl)sulfonamides were identified as new selective Raf inhibitors. The compounds potently inhibit B-RafV600E with low nanomolar IC50 values and exhibit excellent target specificity in a selectivity profiling investigation against 468 kinases. They strongly suppress proliferation of a panel of human cancer cell lines and patient-derived melanoma cells with B-RafV600E mutation while being significantly less potent to the cells with B-RafWT. The compounds also display favorable pharmacokinetic properties with a preferred example (3s) demonstrating significant in vivo antitumor efficacy in a xenograft mouse model of B-RafV600E mutated Colo205 human colorectal cancer cells, supporting it as a promising lead compound for further anticancer drug discovery. PMID:26005530

  17. Discovery of Isonicotinamides as Highly Selective, Brain Penetrable, and Orally Active Glycogen Synthase Kinase-3 Inhibitors.

    PubMed

    Luo, Guanglin; Chen, Ling; Burton, Catherine R; Xiao, Hong; Sivaprakasam, Prasanna; Krause, Carol M; Cao, Yang; Liu, Nengyin; Lippy, Jonathan; Clarke, Wendy J; Snow, Kimberly; Raybon, Joseph; Arora, Vinod; Pokross, Matt; Kish, Kevin; Lewis, Hal A; Langley, David R; Macor, John E; Dubowchik, Gene M

    2016-02-11

    GSK-3 is a serine/threonine kinase that has numerous substrates. Many of these proteins are involved in the regulation of diverse cellular functions, including metabolism, differentiation, proliferation, and apoptosis. Inhibition of GSK-3 may be useful in treating a number of diseases including Alzheimer's disease (AD), type II diabetes, mood disorders, and some cancers, but the approach poses significant challenges. Here, we present a class of isonicotinamides that are potent, highly kinase-selective GSK-3 inhibitors, the members of which demonstrated oral activity in a triple-transgenic mouse model of AD. The remarkably high kinase selectivity and straightforward synthesis of these compounds bode well for their further exploration as tool compounds and therapeutics. PMID:26751161

  18. Structure-based design of 2-aminopyridine oxazolidinones as potent and selective tankyrase inhibitors.

    PubMed

    Huang, Hongbing; Guzman-Perez, Angel; Acquaviva, Lisa; Berry, Virginia; Bregman, Howard; Dovey, Jennifer; Gunaydin, Hakan; Huang, Xin; Huang, Liyue; Saffran, Doug; Serafino, Randy; Schneider, Steve; Wilson, Cindy; DiMauro, Erin F

    2013-12-12

    Aberrant activation of the Wnt pathway has been implicated in the development and formation of many cancers. TNKS inhibition has been shown to antagonize Wnt signaling via Axin stabilization in APC mutant colon cancer cell lines. We employed structure-based design to identify a series of 2-aminopyridine oxazolidinones as potent and selective TNKS inhibitors. These compounds exhibited good enzyme and cell potency as well as selectivity over other PARP isoforms. Co-crystal structures of these 2-aminopyridine oxazolidinones complexed to TNKS reveal an induced-pocket binding mode that does not involve interactions with the nicotinamide binding pocket. Oral dosing of lead compounds 3 and 4 resulted in significant effects on several Wnt-pathway biomarkers in a three day DLD-1 mouse tumor PD model. PMID:24900633

  19. The Therapeutic Potential of Class I Selective Histone Deacetylase Inhibitors in Ovarian Cancer

    PubMed Central

    Khabele, Dineo

    2014-01-01

    Epithelial ovarian cancer remains the deadliest gynecologic malignancy. Despite advances in treatment, new approaches are needed. Histone deacetylases (HDACs) are a family of enzymes that regulate gene expression by removing acetyl groups from lysine residues on histones and non-histone proteins. Inhibition of HDACs with small molecules has led to the development of histone deacetylase inhibitors (HDACi) that are in clinical use, primarily for hematologic malignancies. Although clinical trials with HDACi as single agents in solid tumors have been disappointing, data from independent labs and recent work by our group show that class I selective HDACi have potent anti-tumor effects in pre-clinical models of ovarian cancer. This review summarizes the role of HDACs in ovarian cancer and the potential niche for selective class I HDACi, particularly HDAC3 in ovarian cancer therapy. PMID:24904826

  20. Select Dietary Phytochemicals Function as Inhibitors of COX-1 but Not COX-2

    PubMed Central

    Li, Haitao; Zhu, Feng; Sun, Yanwen; Li, Bing; Oi, Naomi; Chen, Hanyong; Lubet, Ronald A.; Bode, Ann M.; Dong, Zigang

    2013-01-01

    Recent clinical trials raised concerns regarding the cardiovascular toxicity of selective cyclooxygenase-2 (COX-2) inhibitors. Many active dietary factors are reported to suppress carcinogenesis by targeting COX-2. A major question was accordingly raised: why has the lifelong use of phytochemicals that likely inhibit COX-2 presumably not been associated with adverse cardiovascular side effects. To answer this question, we selected a library of dietary-derived phytochemicals and evaluated their potential cardiovascular toxicity in human umbilical vein endothelial cells. Our data indicated that the possibility of cardiovascular toxicity of these dietary phytochemicals was low. Further mechanistic studies revealed that the actions of these phytochemicals were similar to aspirin in that they mainly inhibited COX-1 rather than COX-2, especially at low doses. PMID:24098505

  1. Combinatorial support vector machines approach for virtual screening of selective multi-target serotonin reuptake inhibitors from large compound libraries.

    PubMed

    Shi, Z; Ma, X H; Qin, C; Jia, J; Jiang, Y Y; Tan, C Y; Chen, Y Z

    2012-02-01

    Selective multi-target serotonin reuptake inhibitors enhance antidepressant efficacy. Their discovery can be facilitated by multiple methods, including in silico ones. In this study, we developed and tested an in silico method, combinatorial support vector machines (COMBI-SVMs), for virtual screening (VS) multi-target serotonin reuptake inhibitors of seven target pairs (serotonin transporter paired with noradrenaline transporter, H(3) receptor, 5-HT(1A) receptor, 5-HT(1B) receptor, 5-HT(2C) receptor, melanocortin 4 receptor and neurokinin 1 receptor respectively) from large compound libraries. COMBI-SVMs trained with 917-1951 individual target inhibitors correctly identified 22-83.3% (majority >31.1%) of the 6-216 dual inhibitors collected from literature as independent testing sets. COMBI-SVMs showed moderate to good target selectivity in misclassifying as dual inhibitors 2.2-29.8% (majority <15.4%) of the individual target inhibitors of the same target pair and 0.58-7.1% of the other 6 targets outside the target pair. COMBI-SVMs showed low dual inhibitor false hit rates (0.006-0.056%, 0.042-0.21%, 0.2-4%) in screening 17 million PubChem compounds, 168,000 MDDR compounds, and 7-8181 MDDR compounds similar to the dual inhibitors. Compared with similarity searching, k-NN and PNN methods, COMBI-SVM produced comparable dual inhibitor yields, similar target selectivity, and lower false hit rate in screening 168,000 MDDR compounds. The annotated classes of many COMBI-SVMs identified MDDR virtual hits correlate with the reported effects of their predicted targets. COMBI-SVM is potentially useful for searching selective multi-target agents without explicit knowledge of these agents. PMID:22064367

  2. The Marine Cyanobacterial Metabolite Gallinamide A is a Potent and Selective Inhibitor of Human Cathepsin L

    PubMed Central

    Miller, Bailey; Friedman, Aaron J; Choi, Hyukjae; Hogan, James; McCammon, J. Andrew; Hook, Vivian; Gerwick, William H.

    2014-01-01

    A number of marine natural products are potent inhibitors of proteases, an important drug target class in human diseases. Hence, marine cyanobacterial extracts were assessed for inhibitory activity to human cathepsin L. Herein, we have shown that gallinamide A potently and selectively inhibits the human cysteine protease, cathepsin L. With 30 min of preincubation, gallinamide A displayed an IC50 of 5.0 nM, and kinetic analysis demonstrated an inhibition constant of ki = 9000 ± 260 M−1 s−1. Preincubation-dilution and activity-probe experiments revealed an irreversible mode of inhibition, and comparative IC50 values display a 28- to 320- fold greater selectivity toward cathepsin L than closely related human cysteine cathepsins V or B. Molecular docking and molecular dynamics simulations were used to determine the pose of gallinamide in the active site of cathepsin L. These data resulted in the identification of a pose characterized by high stability, a consistent hydrogen bond network, and the reactive Michael acceptor enamide of gallinamide A positioned near the active site cysteine of the protease, leading to a proposed mechanism of covalent inhibition. These data reveal and characterize the novel activity of gallinamide A as a potent inhibitor of human cathepsin L. PMID:24364476

  3. Potent and selective inhibitors of glutathione S-transferase omega 1 that impair cancer drug resistance.

    PubMed

    Tsuboi, Katsunori; Bachovchin, Daniel A; Speers, Anna E; Spicer, Timothy P; Fernandez-Vega, Virneliz; Hodder, Peter; Rosen, Hugh; Cravatt, Benjamin F

    2011-10-19

    Glutathione S-transferases (GSTs) are a superfamily of enzymes that conjugate glutathione to a wide variety of both exogenous and endogenous compounds for biotransformation and/or removal. Glutathione S-tranferase omega 1 (GSTO1) is highly expressed in human cancer cells, where it has been suggested to play a role in detoxification of chemotherapeutic agents. Selective inhibitors of GSTO1 are, however, required to test the role that this enzyme plays in cancer and other (patho)physiological processes. With this goal in mind, we performed a fluorescence polarization activity-based protein profiling (fluopol-ABPP) high-throughput screen (HTS) with GSTO1 and the Molecular Libraries Small Molecule Repository (MLSMR) 300K+ compound library. This screen identified a class of selective and irreversible α-chloroacetamide inhibitors of GSTO1, which were optimized to generate an agent KT53 that inactivates GSTO1 with excellent in vitro (IC(50) = 21 nM) and in situ (IC(50) = 35 nM) potency. Cancer cells treated with KT53 show heightened sensitivity to the cytotoxic effects of cisplatin, supporting a role for GSTO1 in chemotherapy resistance. PMID:21899313

  4. Potent and Selective Inhibitors of Glutathione S-transferase Omega 1 that Impair Cancer Drug Resistance

    PubMed Central

    Tsuboi, Katsunori; Bachovchin, Daniel A.; Speers, Anna E.; Spicer, Timothy P.; Fernandez-Vega, Virneliz; Hodder, Peter; Rosen, Hugh; Cravatt, Benjamin F.

    2011-01-01

    Glutathione S-transferases (GSTs) are a superfamily of enzymes that conjugate glutathione to a wide variety of both exogenous and endogenous compounds for biotransformation and/or removal. Glutathione S-tranferase omega 1 (GSTO1) is highly expressed in human cancer cells, where it has been suggested to play a role in detoxification of chemotherapeutic agents. Selective inhibitors of GSTO1 are, however, required to test the role that this enzyme plays in cancer and other (patho)physiological processes. With this goal in mind, we performed a fluorescence polarization activity-based protein profiling (fluopol-ABPP) high-throughput screen (HTS) with GSTO1 and the Molecular Libraries Small Molecule Repository (MLSMR) 300K+ compound library. This screen identified a class of selective and irreversible α-chloroacetamide inhibitors of GSTO1, which were optimized to generate an agent KT53 that inactivates GSTO1 with excellent in vitro (IC50 = 21 nM) and in situ (IC50 = 35 nM) potency. Cancer cells treated with KT53 show heightened sensitivity to the cytotoxic effects of cisplatin, supporting a role for GSTO1 in the detoxification of chemo-therapeutic agents PMID:21899313

  5. A novel cdk2-selective inhibitor, SU9516, induces apoptosis in colon carcinoma cells.

    PubMed

    Lane, M E; Yu, B; Rice, A; Lipson, K E; Liang, C; Sun, L; Tang, C; McMahon, G; Pestell, R G; Wadler, S

    2001-08-15

    Recent studies have indicated that the development of cyclin-dependent kinase (cdk)2 inhibitors that deregulate E2F are a plausible pharmacological strategy for novel antineoplastic agents. We show here that 3-[1-(3H-Imidazol-4-yl)-meth-(Z)-ylidene]-5-methoxy-1,3-dihydro-indol-2-one (SU9516), a novel 3-substituted indolinone compound, binds to and selectively inhibits the activity of cdk2. This inhibition results in a time-dependent decrease (4-64%) in the phosphorylation of the retinoblastoma protein pRb, an increase in caspase-3 activation (5-84%), and alterations in cell cycle resulting in either a G(0)-G(1) or a G(2)-M block. We also report here cell line differences in the cdk-dependent phosphorylation of pRb. These findings demonstrate that SU9516 is a selective cdk2 inhibitor and support the theory that compounds that inhibit cdk2 are viable resources in the development of new antineoplastic agents. PMID:11507069

  6. Potent and selective inhibition of polycythemia by the quinoxaline JAK2 inhibitor NVP-BSK805.

    PubMed

    Baffert, Fabienne; Régnier, Catherine H; De Pover, Alain; Pissot-Soldermann, Carole; Tavares, Gisele A; Blasco, Francesca; Brueggen, Josef; Chène, Patrick; Drueckes, Peter; Erdmann, Dirk; Furet, Pascal; Gerspacher, Marc; Lang, Marc; Ledieu, David; Nolan, Lynda; Ruetz, Stephan; Trappe, Joerg; Vangrevelinghe, Eric; Wartmann, Markus; Wyder, Lorenza; Hofmann, Francesco; Radimerski, Thomas

    2010-07-01

    The recent discovery of an acquired activating point mutation in JAK2, substituting valine at amino acid position 617 for phenylalanine, has greatly improved our understanding of the molecular mechanism underlying chronic myeloproliferative neoplasms. Strikingly, the JAK2(V617F) mutation is found in nearly all patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia and primary myelofibrosis. Thus, JAK2 represents a promising target for the treatment of myeloproliferative neoplasms and considerable efforts are ongoing to discover and develop inhibitors of the kinase. Here, we report potent inhibition of JAK2(V617F) and JAK2 wild-type enzymes by a novel substituted quinoxaline, NVP-BSK805, which acts in an ATP-competitive manner. Within the JAK family, NVP-BSK805 displays more than 20-fold selectivity towards JAK2 in vitro, as well as excellent selectivity in broader kinase profiling. The compound blunts constitutive STAT5 phosphorylation in JAK2(V617F)-bearing cells, with concomitant suppression of cell proliferation and induction of apoptosis. In vivo, NVP-BSK805 exhibited good oral bioavailability and a long half-life. The inhibitor was efficacious in suppressing leukemic cell spreading and splenomegaly in a Ba/F3 JAK2(V617F) cell-driven mouse mechanistic model. Furthermore, NVP-BSK805 potently suppressed recombinant human erythropoietin-induced polycythemia and extramedullary erythropoiesis in mice and rats. PMID:20587663

  7. CBP30, a selective CBP/p300 bromodomain inhibitor, suppresses human Th17 responses

    PubMed Central

    Hammitzsch, Ariane; Tallant, Cynthia; Fedorov, Oleg; O’Mahony, Alison; Brennan, Paul E.; Hay, Duncan A.; Martinez, Fernando O.; Al-Mossawi, M. Hussein; de Wit, Jelle; Vecellio, Matteo; Wells, Christopher; Wordsworth, Paul; Müller, Susanne; Knapp, Stefan; Bowness, Paul

    2015-01-01

    Th17 responses are critical to a variety of human autoimmune diseases, and therapeutic targeting with monoclonal antibodies against IL-17 and IL-23 has shown considerable promise. Here, we report data to support selective bromodomain blockade of the transcriptional coactivators CBP (CREB binding protein) and p300 as an alternative approach to inhibit human Th17 responses. We show that CBP30 has marked molecular specificity for the bromodomains of CBP and p300, compared with 43 other bromodomains. In unbiased cellular testing on a diverse panel of cultured primary human cells, CBP30 reduced immune cell production of IL-17A and other proinflammatory cytokines. CBP30 also inhibited IL-17A secretion by Th17 cells from healthy donors and patients with ankylosing spondylitis and psoriatic arthritis. Transcriptional profiling of human T cells after CBP30 treatment showed a much more restricted effect on gene expression than that observed with the pan-BET (bromo and extraterminal domain protein family) bromodomain inhibitor JQ1. This selective targeting of the CBP/p300 bromodomain by CBP30 will potentially lead to fewer side effects than with the broadly acting epigenetic inhibitors currently in clinical trials. PMID:26261308

  8. The marine cyanobacterial metabolite gallinamide A is a potent and selective inhibitor of human cathepsin L.

    PubMed

    Miller, Bailey; Friedman, Aaron J; Choi, Hyukjae; Hogan, James; McCammon, J Andrew; Hook, Vivian; Gerwick, William H

    2014-01-24

    A number of marine natural products are potent inhibitors of proteases, an important drug target class in human diseases. Hence, marine cyanobacterial extracts were assessed for inhibitory activity to human cathepsin L. Herein, we have shown that gallinamide A potently and selectively inhibits the human cysteine protease cathepsin L. With 30 min of preincubation, gallinamide A displayed an IC50 of 5.0 nM, and kinetic analysis demonstrated an inhibition constant of ki = 9000 ± 260 M(-1) s(-1). Preincubation-dilution and activity-probe experiments revealed an irreversible mode of inhibition, and comparative IC50 values display a 28- to 320-fold greater selectivity toward cathepsin L than closely related human cysteine cathepsin V or B. Molecular docking and molecular dynamics simulations were used to determine the pose of gallinamide in the active site of cathepsin L. These data resulted in the identification of a pose characterized by high stability, a consistent hydrogen bond network, and the reactive Michael acceptor enamide of gallinamide A positioned near the active site cysteine of the protease, leading to a proposed mechanism of covalent inhibition. These data reveal and characterize the novel activity of gallinamide A as a potent inhibitor of human cathepsin L. PMID:24364476

  9. Hedgehog inhibitors selectively target cell migration and adhesion of mantle cell lymphoma in bone marrow microenvironment

    PubMed Central

    Zhang, Han; Chen, Zheng; Neelapu, Sattva S.; Romaguera, Jorge; McCarty, Nami

    2016-01-01

    The clinical benefits of a Hedgehog (Hh) inhibitor, LDE225 (NPV-LDE-225, Erismodegib), have been unclear in hematological cancers. Here, we report that LDE225 selectively inhibited migration and adhesion of mantle cell lymphoma (MCL) to bone marrows via very late antigen-4 (VLA-4) mediated inactivation of focal adhesion kinase (FAK) signaling. LDE225 treatment not only affected MCL cells, but also modulated stromal cells within the bone marrow microenvironment by decreasing their production of SDF-1, IL-6 and VCAM-1, the ligand for VLA-4. Surprisingly, LDE225 treatment alone did not suppress cell proliferation due to increased CXCR4 expression mediated by reactive oxygen species (ROS). The increased ROS/CXCR4 further stimulated autophagy formation. The combination of LDE225 with the autophagy inhibitors further enhanced MCL cell death. Our data, for the first time, revealed LDE225 selectively targets MCL cells migration and adhesion to bone marrows. The ineffectiveness of LDE225 in MCL is due to autophagy formation, which in turn increases cell viability. Inhibiting autophagy will be an effective adjuvant therapy for LDE225 in MCL, especially for advanced MCL patients with bone marrow involvement. PMID:26885608

  10. Hedgehog inhibitors selectively target cell migration and adhesion of mantle cell lymphoma in bone marrow microenvironment.

    PubMed

    Zhang, Han; Chen, Zheng; Neelapu, Sattva S; Romaguera, Jorge; McCarty, Nami

    2016-03-22

    The clinical benefits of a Hedgehog (Hh) inhibitor, LDE225 (NPV-LDE-225, Erismodegib), have been unclear in hematological cancers. Here, we report that LDE225 selectively inhibited migration and adhesion of mantle cell lymphoma (MCL) to bone marrows via very late antigen-4 (VLA-4) mediated inactivation of focal adhesion kinase (FAK) signaling. LDE225 treatment not only affected MCL cells, but also modulated stromal cells within the bone marrow microenvironment by decreasing their production of SDF-1, IL-6 and VCAM-1, the ligand for VLA-4. Surprisingly, LDE225 treatment alone did not suppress cell proliferation due to increased CXCR4 expression mediated by reactive oxygen species (ROS). The increased ROS/CXCR4 further stimulated autophagy formation. The combination of LDE225 with the autophagy inhibitors further enhanced MCL cell death. Our data, for the first time, revealed LDE225 selectively targets MCL cells migration and adhesion to bone marrows. The ineffectiveness of LDE225 in MCL is due to autophagy formation, which in turn increases cell viability. Inhibiting autophagy will be an effective adjuvant therapy for LDE225 in MCL, especially for advanced MCL patients with bone marrow involvement. PMID:26885608

  11. Cyclooxygenase-1-Selective Inhibitors Based on the (E)-2′-Des-methyl-sulindac Sulfide Scaffold

    PubMed Central

    2012-01-01

    Prostaglandins (PGs) are powerful lipid mediators in many physiological and pathophysiological responses. They are produced by oxidation of arachidonic acid (AA) by cyclooxygenases (COX-1 and COX-2) followed by metabolism of endoperoxide intermediates by terminal PG synthases. PG biosynthesis is inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs). Specific inhibition of COX-2 has been extensively investigated, but relatively few COX-1-selective inhibitors have been described. Recent reports of a possible contribution of COX-1 in analgesia, neuroinflammation, or carcinogenesis suggest that COX-1 is a potential therapeutic target. We designed, synthesized, and evaluated a series of (E)-2′-des-methyl-sulindac sulfide (E-DMSS) analogues for inhibition of COX-1. Several potent and selective inhibitors were discovered, and the most promising compounds were active against COX-1 in intact ovarian carcinoma cells (OVCAR-3). The compounds inhibited tumor cell proliferation but only at concentrations >100-fold higher than the concentrations that inhibit COX-1 activity. E-DMSS analogues may be useful probes of COX-1 biology in vivo and promising leads for COX-1-targeted therapeutic agents. PMID:22263894

  12. NF-κB drives acquired resistance to a novel mutant-selective EGFR inhibitor

    PubMed Central

    Galvani, Elena; Sun, Jing; Leon, Leticia G.; Sciarrillo, Rocco; Narayan, Ravi S.; Tjin Tham Sjin, Robert; Lee, Kwangho; Ohashi, Kadoaki; Heideman, Daniëlle A.M.; Alfieri, Roberta R.; Heynen, Guus J.; Bernards, René; Smit, Egbert F.; Pao, William; Peters, Godefridus J.; Giovannetti, Elisa

    2015-01-01

    The clinical efficacy of EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) harbouring activating EGFR mutations is limited by the emergence of acquired resistance, mostly ascribed to the secondary EGFR-T790M mutation. Selective EGFR-T790M inhibitors have been proposed as a new, extremely relevant therapeutic approach. Here, we demonstrate that the novel irreversible EGFR-TKI CNX-2006, a structural analog of CO-1686, currently tested in a phase-1/2 trial, is active against in vitro and in vivo NSCLC models expressing mutant EGFR, with minimal effect on the wild-type receptor. By integration of genetic and functional analyses in isogenic cell pairs we provide evidence of the crucial role played by NF-κB1 in driving CNX-2006 acquired resistance and show that NF-κB activation may replace the oncogenic EGFR signaling in NSCLC when effective and persistent inhibition of the target is achieved in the presence of the T790M mutation. In this context, we demonstrate that the sole, either genetic or pharmacologic, inhibition of NF-κB is sufficient to reduce the viability of cells that adapted to EGFR-TKIs. Overall, our findings support the rational inhibition of members of the NF-κB pathway as a promising therapeutic option for patients who progress after treatment with novel mutant-selective EGFR-TKIs. PMID:26015408

  13. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2[S

    PubMed Central

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-01-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  14. Design and optimization of highly-selective fungal CYP51 inhibitors.

    PubMed

    Hoekstra, William J; Garvey, Edward P; Moore, William R; Rafferty, Stephen W; Yates, Christopher M; Schotzinger, Robert J

    2014-08-01

    While the orally-active azoles such as voriconazole and itraconazole are effective antifungal agents, they potently inhibit a broad range of off-target human cytochrome P450 enzymes (CYPs) leading to various safety issues (e.g., drug-drug interactions, liver toxicity). Herein, we describe rationally-designed, broad-spectrum antifungal agents that are more selective for the target fungal enzyme, CYP51, than related human CYP enzymes such as CYP3A4. Using proprietary methodology, the triazole metal-binding group found in current clinical agents was replaced with novel, less avid metal-binding groups in concert with potency-enhancing molecular scaffold modifications. This process produced a unique series of fungal CYP51-selective inhibitors that included the oral antifungal 7d (VT-1161), now in Phase 2 clinical trials. This series exhibits excellent potency against key yeast and dermatophyte strains. The chemical methodology described is potentially applicable to the design of new and more effective metalloenzyme inhibitor treatments for a broad array of diseases. PMID:24948565

  15. An update on the pharmacokinetics and pharmacodynamics of alisertib, a selective Aurora kinase A inhibitor.

    PubMed

    Durlacher, Cameron T; Li, Zhi-Ling; Chen, Xiao-Wu; He, Zhi-Xu; Zhou, Shu-Feng

    2016-06-01

    Human Aurora kinases, including Aurora kinase A (AURKA), B (AURKB), and C (AURKC), play an essential role in mitotic events such as monitoring of the mitotic checkpoint, creation of bipolar mitotic spindle and alignment of centrosomes on it, also regulating centrosome separation, bio-orientation of chromosomes and cytokinesis. AURKA and AURKB are key regulators of mitosis and centrosome via polymerizing microfilaments and controlling chromatid segregation. In particular, AURKA plays critical roles in the regulation of mitotic entry, centrosome function, bipolar spindle assembly, and chromosome segregation. AURKA has been found to be overexpressed in various solid and haematological cancers and has been linked with poor prognosis. Its important role in cancer initiation, growth, and metastasis has brought the focus to search for potent and selective AURKA inhibitors for cancer treatment. MLN8237, also known as alisertib, is one selective AURKA inhibitor that has shown remarkable anticancer effects in preclinical studies. Alisertib exhibits favourable pharmacokinetic properties. Alisertib has generally showed good partial response rates of 4-52% and good safety profiles in Phase I and II trials when it is solely administered as well as combined with cytotoxic chemotherapeutic drugs. Recently, the multicentre, randomized Phase III study of alisertib in patients with relapsed or refractory peripheral T-cell lymphoma has been discontinued due to unsatisfactory efficacy. The low risk of side effects, accessibility, and effectiveness of alisertib makes it a new promising anticancer therapy and further mechanistic and clinical studies are warranted. PMID:26999067

  16. Potent and Selective Inhibitors of MTH1 Probe Its Role in Cancer Cell Survival.

    PubMed

    Kettle, Jason G; Alwan, Husam; Bista, Michal; Breed, Jason; Davies, Nichola L; Eckersley, Kay; Fillery, Shaun; Foote, Kevin M; Goodwin, Louise; Jones, David R; Käck, Helena; Lau, Alan; Nissink, J Willem M; Read, Jon; Scott, James S; Taylor, Ben; Walker, Graeme; Wissler, Lisa; Wylot, Marta

    2016-03-24

    Recent literature has claimed that inhibition of the enzyme MTH1 can eradicate cancer. MTH1 is one of the "housekeeping" enzymes that are responsible for hydrolyzing damaged nucleotides in cells and thus prevent them from being incorporated into DNA. We have developed orthogonal and chemically distinct tool compounds to those published in the literature to allow us to test the hypothesis that inhibition of MTH1 has wide applicability in the treatment of cancer. Here we present the work that led to the discovery of three structurally different series of MTH1 inhibitors with excellent potency, selectivity, and proven target engagement in cells. None of these compounds elicited the reported cellular phenotype, and additional siRNA and CRISPR experiments further support these observations. Critically, the difference between the responses of our highly selective inhibitors and published tool compounds suggests that the effect reported for the latter may be due to off-target cytotoxic effects. As a result, we conclude that the role of MTH1 in carcinogenesis and utility of its inhibition is yet to be established. PMID:26878898

  17. A selective inhibitor of PRMT5 with in vivo and in vitro potency in MCL models.

    PubMed

    Chan-Penebre, Elayne; Kuplast, Kristy G; Majer, Christina R; Boriack-Sjodin, P Ann; Wigle, Tim J; Johnston, L Danielle; Rioux, Nathalie; Munchhof, Michael J; Jin, Lei; Jacques, Suzanne L; West, Kip A; Lingaraj, Trupti; Stickland, Kimberly; Ribich, Scott A; Raimondi, Alejandra; Scott, Margaret Porter; Waters, Nigel J; Pollock, Roy M; Smith, Jesse J; Barbash, Olena; Pappalardi, Melissa; Ho, Thau F; Nurse, Kelvin; Oza, Khyati P; Gallagher, Kathleen T; Kruger, Ryan; Moyer, Mikel P; Copeland, Robert A; Chesworth, Richard; Duncan, Kenneth W

    2015-06-01

    Protein arginine methyltransferase-5 (PRMT5) is reported to have a role in diverse cellular processes, including tumorigenesis, and its overexpression is observed in cell lines and primary patient samples derived from lymphomas, particularly mantle cell lymphoma (MCL). Here we describe the identification and characterization of a potent and selective inhibitor of PRMT5 with antiproliferative effects in both in vitro and in vivo models of MCL. EPZ015666 (GSK3235025) is an orally available inhibitor of PRMT5 enzymatic activity in biochemical assays with a half-maximal inhibitory concentration (IC50) of 22 nM and broad selectivity against a panel of other histone methyltransferases. Treatment of MCL cell lines with EPZ015666 led to inhibition of SmD3 methylation and cell death, with IC50 values in the nanomolar range. Oral dosing with EPZ015666 demonstrated dose-dependent antitumor activity in multiple MCL xenograft models. EPZ015666 represents a validated chemical probe for further study of PRMT5 biology and arginine methylation in cancer and other diseases. PMID:25915199

  18. Potent and Selective CK2 Kinase Inhibitors with Effects on Wnt Pathway Signaling in Vivo.

    PubMed

    Dowling, James E; Alimzhanov, Marat; Bao, Larry; Chuaqui, Claudio; Denz, Christopher R; Jenkins, Emma; Larsen, Nicholas A; Lyne, Paul D; Pontz, Timothy; Ye, Qing; Holdgate, Geoff A; Snow, Lindsay; O'Connell, Nichole; Ferguson, Andrew D

    2016-03-10

    The Wnt pathway is an evolutionarily conserved and tightly regulated signaling network with important roles in embryonic development and adult tissue regeneration. Impaired Wnt pathway regulation, arising from mutations in Wnt signaling components, such as Axin, APC, and β-catenin, results in uncontrolled cell growth and triggers oncogenesis. To explore the reported link between CK2 kinase activity and Wnt pathway signaling, we sought to identify a potent, selective inhibitor of CK2 suitable for proof of concept studies in vivo. Starting from a pyrazolo[1,5-a]pyrimidine lead (2), we identified compound 7h, a potent CK2 inhibitor with picomolar affinity that is highly selectivity against other kinase family enzymes and inhibits Wnt pathway signaling (IC50 = 50 nM) in DLD-1 cells. In addition, compound 7h has physicochemical properties that are suitable for formulation as an intravenous solution, has demonstrated good pharmacokinetics in preclinical species, and exhibits a high level of activity as a monotherapy in HCT-116 and SW-620 xenografts. PMID:26985319

  19. An isoform-selective, small-molecule inhibitor targets the autoregulatory mechanism of p21-activated kinase

    PubMed Central

    Deacon, Sean W.; Beeser, Alexander; Fukui, Jami A.; Rennefahrt, Ulrike E. E.; Myers, Cynthia; Chernoff, Jonathan; Peterson, Jeffrey R.

    2015-01-01

    SUMMARY Autoregulatory domains found within kinases may provide more unique targets for chemical inhibitors than the conserved ATP-binding pocket targeted by most inhibitors. The kinase Pak1 contains an autoinhibitory domain that suppresses the catalytic activity of its kinase domain. Pak1 activators relieve this autoinhibition and initiate conformational rearrangements and autophosphorylation events leading to kinase activation. We developed a screen for allosteric inhibitors targeting Pak1 activation and identified the inhibitor IPA-3. Remarkably, pre-activated Pak1 is resistant to IPA-3. IPA-3 also inhibits activation of related Pak isoforms regulated by autoinhibition, but not more distantly related Paks, nor >200 other kinases tested. Pak1 inhibition by IPA-3 in live cells supports a critical role for Pak in PDGF-stimulated Erk activation. These studies illustrate a novel strategy for kinase inhibition and introduce a highly selective, cell-permeable chemical inhibitor of Pak. PMID:18420139

  20. 3-Amido pyrrolopyrazine JAK kinase inhibitors: development of a JAK3 vs JAK1 selective inhibitor and evaluation in cellular and in vivo models.

    PubMed

    Soth, Michael; Hermann, Johannes C; Yee, Calvin; Alam, Muzaffar; Barnett, Jim W; Berry, Pamela; Browner, Michelle F; Frank, Karl; Frauchiger, Sandra; Harris, Seth; He, Yang; Hekmat-Nejad, Mohammad; Hendricks, Than; Henningsen, Robert; Hilgenkamp, Ramona; Ho, Hoangdung; Hoffman, Ann; Hsu, Pei-Yuan; Hu, Dong-Qing; Itano, Andrea; Jaime-Figueroa, Saul; Jahangir, Alam; Jin, Sue; Kuglstatter, Andreas; Kutach, Alan K; Liao, Cheng; Lynch, Stephen; Menke, John; Niu, Linghao; Patel, Vaishali; Railkar, Aruna; Roy, Douglas; Shao, Ada; Shaw, David; Steiner, Sandra; Sun, Yongliang; Tan, Seng-Lai; Wang, Sandra; Vu, Minh Diem

    2013-01-10

    The Janus kinases (JAKs) are involved in multiple signaling networks relevant to inflammatory diseases, and inhibition of one or more members of this class may modulate disease activity or progression. We optimized a new inhibitor scaffold, 3-amido-5-cyclopropylpyrrolopyrazines, to a potent example with reasonable kinome selectivity, including selectivity for JAK3 versus JAK1, and good biopharmaceutical properties. Evaluation of this analogue in cellular and in vivo models confirmed functional selectivity for modulation of a JAK3/JAK1-dependent IL-2 stimulated pathway over a JAK1/JAK2/Tyk2-dependent IL-6 stimulated pathway. PMID:23214979

  1. Benzoylbenzimidazole-based selective inhibitors targeting Cryptosporidium parvum and Toxoplasma gondii calcium-dependent protein kinase-1

    PubMed Central

    Zhang, Zhongsheng; Ojo, Kayode K.; Johnson, Steven M.; Larson, Eric T.; He, Penqing; Geiger, Jennifer A.; Castellanos-Gonzalez, Alejandro; White, A. Clinton; Parsons, Marilyn; Merritt, Ethan A.; Maly, Dustin J.; Verlinde, Christophe L. M. J.; Van Voorhis, Wesley C.; Fan, Erkang

    2012-01-01

    Calcium-dependent protein kinase-1 (CDPK1) from Cryptosporidium parvum (CpCDPK1) and Toxoplasma gondii (TgCDPK1) have become attractive targets for discovering selective inhibitors to combat infections caused by these protozoa. We used structure-based design to improve a series of benzoylbenzimidazole-based compounds in terms of solubility, selectivity, and potency against CpCDPK1 and TgCDPK1. The best inhibitors show inhibitory potencies below 50 nM and selectivity well above 200-fold over two human kinases with small gatekeeper residues. PMID:22795629

  2. 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.

  3. Acquisition of a Potent and Selective TC-PTP Inhibitor via a Stepwise Fluorophoretagged Combinatorial Synthesis and Screening Strategy

    PubMed Central

    Zhang, Sheng; Chen, Lan; Luo, Yong; Gunawan, Andrea; Lawrence, David S.; Zhang, Zhong-Yin

    2009-01-01

    Protein tyrosine phosphatases (PTPs) regulate a broad range of cellular processes including proliferation, differentiation, migration, apoptosis, and the immune responses. Dysfunction of PTP activity is associated with cancers, metabolic syndromes, and autoimmune disorders. Consequently, small molecule PTP inhibitors should not only serve as powerful tools to delineate the physiological roles of these enzymes in vivo, but also as lead compounds for therapeutic development. We describe a novel stepwise fluorophore-tagged combinatorial library synthesis and competitive fluorescence polarization screening approach that transforms a weak and general PTP inhibitor into an extremely potent and selective TC-PTP inhibitor with highly efficacious cellular activity. The result serves as a proof-of-concept in PTP inhibitor development, as it demonstrates the feasibility of acquiring potent, yet highly selective, cell permeable PTP inhibitory agents. Given the general nature of the approach, this strategy should be applicable to other PTP targets. PMID:19737019

  4. Discovery of 3-Alkoxyamino-5-(pyridin-2-ylamino)pyrazine-2-carbonitriles as Selective, Orally Bioavailable CHK1 Inhibitors

    PubMed Central

    2012-01-01

    Inhibitors of checkpoint kinase 1 (CHK1) are of current interest as potential antitumor agents, but the most advanced inhibitor series reported to date are not orally bioavailable. A novel series of potent and orally bioavailable 3-alkoxyamino-5-(pyridin-2-ylamino)pyrazine-2-carbonitrile CHK1 inhibitors was generated by hybridization of two lead scaffolds derived from fragment-based drug design and optimized for CHK1 potency and high selectivity using a cell-based assay cascade. Efficient in vivo pharmacokinetic assessment was used to identify compounds with prolonged exposure following oral dosing. The optimized compound (CCT244747) was a potent and highly selective CHK1 inhibitor, which modulated the DNA damage response pathway in human tumor xenografts and showed antitumor activity in combination with genotoxic chemotherapies and as a single agent. PMID:23082860

  5. The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

    PubMed Central

    2012-01-01

    Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2) inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR) of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD). The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs) for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months) prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021) for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer. PMID:23217168

  6. Selective Serotonin Reuptake Inhibitors for Premenstrual Syndrome and Premenstrual Dysphoric Disorder

    PubMed Central

    Shah, Nirav R.; Jones, J. B.; Aperi, Jaclyn; Shemtov, Rachel; Karne, Anita; Borenstein, Jeff

    2009-01-01

    OBJECTIVE To systematically review evidence of the treatment benefits of selective serotonin reuptake inhibitors (SSRIs) for symptoms related to severe premenstrual syndrome (PMS) and premenstrual dysphoric disorder. DATA SOURCES We conducted electronic database searches of MEDLINE, Web of Science, Cochrane Library, Embase, PsycINFO, and Cinahl through March 2007, and hand-searched reference lists and pertinent journals. METHODS OF STUDY SELECTION Studies included in the review were double-blind, randomized, controlled trials comparing an SSRI with placebo that reported a change in a validated score of premenstrual symptomatology. Studies had to report follow-up for any duration longer than one menstrual cycle among premenopausal women who met clinical diagnostic criteria for PMS or premenstrual dysphoric disorder. From 2,132 citations identified, we pooled results from 29 studies (in 19 citations) using random-effects meta-analyses and present results as odds ratios (ORs). TABULATION, INTEGRATION, AND RESULTS Our metaanalysis, which included 2,964 women, demonstrates that SSRIs are effective for treating PMS and premenstrual dysphoric disorder (OR 0.40, 95% confidence interval [CI] 0.31-0.51). Intermittent dosing regimens were found to be less effective (OR 0.55, 95% CI 0.45-0.68) than continuous dosing regimens (OR 0.28, 95% CI 0.18-0.42). No SSRI was demonstrably better than another. The choice of outcome measurement instrument was associated with effect size estimates. The overall effect size is smaller than reported previously. CONCLUSION Selective serotonin reuptake inhibitors were found to be effective in treating premenstrual symptoms, with continuous dosing regimens favored for effectiveness. PMID:18448752

  7. Highly sensitive and selective fluorescence assays for rapid screening of endothelin-converting enzyme inhibitors.

    PubMed Central

    Luciani, N; de Rocquigny, H; Turcaud, S; Romieu, A; Roques, B P

    2001-01-01

    The highly potent vasoconstrictor peptide endothelin (ET) is generated from an inactive precursor, big endothelin (bET), by endothelin-converting enzyme (ECE). ECE is a phosphoramidon-sensitive zinc metallopeptidase, which is closely related to neprilysin (neutral endopeptidase). It is possible that compounds which inhibit the formation of ET may be used as new drugs for the treatment of cardiovascular diseases. Such an approach requires a fast, simple and selective assay to measure ECE activity, allowing rapid screening of inhibitors. We describe here two new ECE substrates based on the concept of 'intramolecularly quenched fluorescence' which may fulfill this aim. One, S(1) [Pya(21)-Nop(22)-bET-1(19--35)], is the (19--35) fragment of the natural peptide big-ET-1(1--38), which is modified by introducing the fluorescent amino acid, pyrenylalanine (Pya), in position 21 and a quencher, p-nitrophenylalanine (Nop), in position 22. The second substrate (S(2)) is a small peptide, Ac-Ser-Gly-Pya-Lys-Ala-Phe-Ala-Nop-Gly-Lys-NH(2), from a biased substrate peptide library. The recombinant, hECE-1c, cleaved both Pya(21)-Nop(22)-bET-1(19--35) and the natural substrate selectively between residues 21 and 22, whereas cleavage occurred between alanine and phenylalanine in the small peptide. In both cases, this generated intense fluorescence emission. The synthesis and kinetic parameters of these substrates are described. These assays, which can be used directly on tissue homogenates, are the most sensitive and selective described to date for ECE, and are easily automated for a high-throughput screening of inhibitors. PMID:11389689

  8. Reduction in cancer risk by selective and nonselective cyclooxygenase-2 (COX-2) inhibitors

    PubMed Central

    Harris, Randall E; Beebe, Joanne; Alshafie, Galal A

    2012-01-01

    We conducted a series of epidemiologic studies to evaluate the chemopreventive effects of aspirin, ibuprofen, and selective cyxlooxygenase-2 (COX-2) inhibitors (coxibs) against cancers of the breast, colon, prostate, and lung. Composite results across all four cancer sites revealed that regular intake of 325 mg aspirin, 200 mg ibuprofen, or standard dosages of coxibs (200 mg celecoxib or 25 mg rofecoxib) produced risk reductions of 49%, 59%, and 64%, respectively. Use of coxibs for at least 2 years was associated with risk reductions of 71%, 70%, 55%, and 60% for breast cancer, colon cancer, prostate cancer and lung cancer, respectively. Effects of ibuprofen were similar to selective coxibs, and slightly stronger than aspirin. These observed effects are consistent with the relative COX-2 selectivity of ibuprofen, coxibs, and aspirin. Acetaminophen, an analgesic without COX-2 activity, had no effect. Overexpression of COX-2 and increased prostaglandin biosynthesis correlates with carcinogenesis and metastasis at most anatomic sites. These results indicate that regular intake of nonselective or selective COX-2 inhibiting agents protects against the development of major forms of cancer.

  9. Discovery of Novel Tricyclic Heterocycles as Potent and Selective DPP-4 Inhibitors for the Treatment of Type 2 Diabetes.

    PubMed

    Wu, Wen-Lian; Hao, Jinsong; Domalski, Martin; Burnett, Duane A; Pissarnitski, Dmitri; Zhao, Zhiqiang; Stamford, Andrew; Scapin, Giovanna; Gao, Ying-Duo; Soriano, Aileen; Kelly, Terri M; Yao, Zuliang; Powles, Mary Ann; Chen, Shiying; Mei, Hong; Hwa, Joyce

    2016-05-12

    In our efforts to develop second generation DPP-4 inhibitors, we endeavored to identify distinct structures with long-acting (once weekly) potential. Taking advantage of X-ray cocrystal structures of sitagliptin and other DPP-4 inhibitors, such as alogliptin and linagliptin bound to DPP-4, and aided by molecular modeling, we designed several series of heterocyclic compounds as initial targets. During their synthesis, an unexpected chemical transformation provided a novel tricyclic scaffold that was beyond our original design. Capitalizing on this serendipitous discovery, we have elaborated this scaffold into a very potent and selective DPP-4 inhibitor lead series, as highlighted by compound 17c. PMID:27190600

  10. ATP-Competitive Inhibitors of the Mammalian Target of Rapamycin: Design and Synthesis of Highly Potent and Selective Pyrazolopyrimidines

    SciTech Connect

    Zask, Arie; Verheijen, Jeroen C.; Curran, Kevin; Kaplan, Joshua; Richard, David J.; Nowak, Pawel; Malwitz, David J.; Brooijmans, Natasja; Bard, Joel; Svenson, Kristine; Lucas, Judy; Toral-Barza, Lourdes; Zhang, Wei-Guo; Hollander, Irwin; Gibbons, James J.; Abraham, Robert T.; Ayral-Kaloustian, Semiramis; Mansour, Tarek S.; Yu, Ker

    2009-09-18

    The mammalian target of rapamycin (mTOR), a central regulator of growth, survival, and metabolism, is a validated target for cancer therapy. Rapamycin and its analogues, allosteric inhibitors of mTOR, only partially inhibit one mTOR protein complex. ATP-competitive, global inhibitors of mTOR that have the potential for enhanced anticancer efficacy are described. Structural features leading to potency and selectivity were identified and refined leading to compounds with in vivo efficacy in tumor xenograft models.

  11. Synthesis and evaluation of pyrazolo[1,5-b]pyridazines as selective cyclin dependent kinase inhibitors

    SciTech Connect

    Stevens, Kirk L.; Reno, Michael J.; Alberti, Jennifer B.; Price, Daniel J.; Kane-Carson, Laurie S.; Knick, Victoria B.; Shewchuk, Lisa M.; Hassell, Anne M.; Veal, James M.; Davis, Stephen T.; Griffin, Robert J.; Peel, Michael R.

    2010-10-01

    A novel series of pyrazolo[1,5-b]pyridazines have been synthesized and identified as cyclin dependant kinase inhibitors potentially useful for the treatment of solid tumors. Modification of the hinge-binding amine or the C(2)- and C(6)-substitutions on the pyrazolopyridazine core provided potent inhibitors of CDK4 and demonstrated enzyme selectivity against VEGFR-2 and GSK3{beta}.

  12. Discovery of potent, selective and orally bioavailable imidazo[1,5-a]pyrazine derived ACK1 inhibitors.

    PubMed

    Jin, Meizhong; Wang, Jing; Kleinberg, Andrew; Kadalbajoo, Mridula; Siu, Kam W; Cooke, Andrew; Bittner, Mark A; Yao, Yan; Thelemann, April; Ji, Qunsheng; Bhagwat, Shripad; Mulvihill, Kristen M; Rechka, Josef A; Pachter, Jonathan A; Crew, Andrew P; Epstein, David; Mulvihill, Mark J

    2013-02-15

    This Letter describes the medicinal chemistry effort towards a series of novel imidazo[1,5-a]pyrazine derived inhibitors of ACK1. Virtual screening led to the discovery of the initial hit, and subsequent exploration of structure-activity relationships and optimization of drug metabolism and pharmacokinetic properties led to the identification of potent, selective and orally bioavailable ACK1 inhibitors. PMID:23317569

  13. SAR Exploration Guided by LE and Fsp(3): Discovery of a Selective and Orally Efficacious RORγ Inhibitor.

    PubMed

    Hirata, Kazuyuki; Kotoku, Masayuki; Seki, Noriyoshi; Maeba, Takaki; Maeda, Katsuya; Hirashima, Shintaro; Sakai, Takayuki; Obika, Shingo; Hori, Akimi; Hase, Yasunori; Yamaguchi, Takayuki; Katsuda, Yoshiaki; Hata, Takahiro; Miyagawa, Naoki; Arita, Kojo; Nomura, Yukihiro; Asahina, Kota; Aratsu, Yusuke; Kamada, Masafumi; Adachi, Tsuyoshi; Noguchi, Masato; Doi, Satoki; Crowe, Paul; Bradley, Erin; Steensma, Ruo; Tao, Haiyan; Fenn, Morgan; Babine, Robert; Li, Xiaolin; Thacher, Scott; Hashimoto, Hiromasa; Shiozaki, Makoto

    2016-01-14

    A novel series of RORγ inhibitors was identified starting with the HTS hit 1. After SAR investigation based on a prospective consideration of two drug-likeness metrics, ligand efficiency (LE) and fraction of sp(3) carbon atoms (Fsp(3)), significant improvement of metabolic stability as well as reduction of CYP inhibition was observed, which finally led to discovery of a selective and orally efficacious RORγ inhibitor 3z. PMID:26819660

  14. 3-Aminopiperidine-Based Peptide Analogues as the First Selective Noncovalent Inhibitors of the Bacterial Cysteine Protease IdeS

    PubMed Central

    2012-01-01

    A series of eight peptides corresponding to the amino acid sequence of the hinge region of IgG and 17 newly synthesized peptide analogues containing a piperidine moiety as a replacement of a glycine residue were tested as potential inhibitors of the bacterial IgG degrading enzyme of Streptococcus pyogenes, IdeS. None of the peptides showed any inhibitory activity of IdeS, but several piperidine-based analogues were identified as inhibitors. Two different analysis methods were used: an SDS-PAGE based assay to detect IgG cleavage products and a surface plasmon resonance spectroscopy based assay to quantify the degree of inhibition. To investigate the selectivity of the inhibitors for IdeS, all compounds were screened against two other related cysteine proteases (SpeB and papain). The selectivity results show that larger analogues that are active inhibitors of IdeS are even more potent as inhibitors of papain, whereas smaller analogues that are active inhibitors of IdeS inhibit neither SpeB nor papain. Two compounds were identified that exhibit high selectivity against IdeS and will be used for further studies. PMID:22369147

  15. Allosteric inhibitors of the Eya2 phosphatase are selective and inhibit Eya2-mediated cell migration.

    PubMed

    Krueger, Aaron B; Drasin, David J; Lea, Wendy A; Patrick, Aaron N; Patnaik, Samarjit; Backos, Donald S; Matheson, Christopher J; Hu, Xin; Barnaeva, Elena; Holliday, Michael J; Blevins, Melanie A; Robin, Tyler P; Eisenmesser, Elan Z; Ferrer, Marc; Simeonov, Anton; Southall, Noel; Reigan, Philip; Marugan, Juan; Ford, Heide L; Zhao, Rui

    2014-06-01

    Eya proteins are essential co-activators of the Six family of transcription factors and contain a unique tyrosine phosphatase domain belonging to the haloacid dehalogenase family of phosphatases. The phosphatase activity of Eya is important for the transcription of a subset of Six1-target genes, and also directs cells to the repair rather than apoptosis pathway upon DNA damage. Furthermore, Eya phosphatase activity has been shown to mediate transformation, invasion, migration, and metastasis of breast cancer cells, making it a potential new drug target for breast cancer. We have previously identified a class of N-arylidenebenzohydrazide compounds that specifically inhibit the Eya2 phosphatase. Herein, we demonstrate that these compounds are reversible inhibitors that selectively inhibit the phosphatase activity of Eya2, but not Eya3. Our mutagenesis results suggest that this class of compounds does not bind to the active site and the binding does not require the coordination with Mg(2+). Moreover, these compounds likely bind within a site on the opposite face of the active site, and function as allosteric inhibitors. We also demonstrate that this class of compounds inhibits Eya2 phosphatase-mediated cell migration, setting the foundation for these molecules to be developed into chemical probes for understanding the specific function of the Eya2 phosphatase and to serve as a prototype for the development of Eya2 phosphatase specific anti-cancer drugs. PMID:24755226

  16. Domain-selective small-molecule inhibitor of histone deacetylase 6 (HDAC6)-mediated tubulin deacetylation

    PubMed Central

    Haggarty, Stephen J.; Koeller, Kathryn M.; Wong, Jason C.; Grozinger, Christina M.; Schreiber, Stuart L.

    2003-01-01

    Protein acetylation, especially histone acetylation, is the subject of both research and clinical investigation. At least four small-molecule histone deacetylase inhibitors are currently in clinical trials for the treatment of cancer. These and other inhibitors also affect microtubule acetylation. A multidimensional, chemical genetic screen of 7,392 small molecules was used to discover “tubacin,” which inhibits α-tubulin deacetylation in mammalian cells. Tubacin does not affect the level of histone acetylation, gene-expression patterns, or cell-cycle progression. We provide evidence that class II histone deacetylase 6 (HDAC6) is the intracellular target of tubacin. Only one of the two catalytic domains of HDAC6 possesses tubulin deacetylase activity, and only this domain is bound by tubacin. Tubacin treatment did not affect the stability of microtubules but did decrease cell motility. HDAC6 overexpression disrupted the localization of p58, a protein that mediates binding of Golgi elements to microtubules. Our results highlight the role of α-tubulin acetylation in mediating the localization of microtubule-associated proteins. They also suggest that small molecules that selectively inhibit HDAC6-mediated α-tubulin deacetylation, a first example of which is tubacin, might have therapeutic applications as antimetastatic and antiangiogenic agents. PMID:12677000

  17. Development of highly potent and selective diaminothiazole inhibitors of cyclin-dependent kinases

    PubMed Central

    Schonbrunn, Ernst; Betzi, Stephane; Alam, Riazul; Martin, Mathew P.; Becker, Andreas; Han, Huijong; Francis, Rawle; Chakrasali, Ramappa; Jakkaraj, Sudhakar; Kazi, Aslamuzzaman; Sebti, Said M.; Cubitt, Christopher L.; Gebhard, Anthony W.; Hazlehurst, Lori A.; Tash, Joseph S.; Georg, Gunda I.

    2013-01-01

    Cyclin-dependent kinases (CDKs) are serine/threonine protein kinases that act as key regulatory elements in cell cycle progression. We describe the development of highly potent diaminothiazole inhibitors of CDK2 (IC50 = 0.0009 – 0.0015 µM) from a single hit compound with weak inhibitory activity (IC50 = 15 µM), discovered by high-throughput screening. Structure-based design was performed using 35 co-crystal structures of CDK2 liganded with distinct analogues of the parent compound. The profiling of compound 51 against a panel of 339 kinases revealed high selectivity for CDKs, with preference for CDK2 and CDK5 over CDK9, CDK1, CDK4 and CDK6. Compound 51 inhibited the proliferation of 13 out of 15 cancer cell lines with IC50 values between 0.27 and 6.9 µM, which correlated with the complete suppression of retinoblastoma phosphorylation and the onset of apoptosis. Combined, the results demonstrate the potential of this new inhibitors series for further development into CDK-specific chemical probes or therapeutics. PMID:23600925

  18. Allosteric Inhibitors of the Eya2 Phosphatase Are Selective and Inhibit Eya2-mediated Cell Migration*

    PubMed Central

    Krueger, Aaron B.; Drasin, David J.; Lea, Wendy A.; Patrick, Aaron N.; Patnaik, Samarjit; Backos, Donald S.; Matheson, Christopher J.; Hu, Xin; Barnaeva, Elena; Holliday, Michael J.; Blevins, Melanie A.; Robin, Tyler P.; Eisenmesser, Elan Z.; Ferrer, Marc; Simeonov, Anton; Southall, Noel; Reigan, Philip; Marugan, Juan; Ford, Heide L.; Zhao, Rui

    2014-01-01

    Eya proteins are essential co-activators of the Six family of transcription factors and contain a unique tyrosine phosphatase domain belonging to the haloacid dehalogenase family of phosphatases. The phosphatase activity of Eya is important for the transcription of a subset of Six1-target genes, and also directs cells to the repair rather than apoptosis pathway upon DNA damage. Furthermore, Eya phosphatase activity has been shown to mediate transformation, invasion, migration, and metastasis of breast cancer cells, making it a potential new drug target for breast cancer. We have previously identified a class of N-arylidenebenzohydrazide compounds that specifically inhibit the Eya2 phosphatase. Herein, we demonstrate that these compounds are reversible inhibitors that selectively inhibit the phosphatase activity of Eya2, but not Eya3. Our mutagenesis results suggest that this class of compounds does not bind to the active site and the binding does not require the coordination with Mg2+. Moreover, these compounds likely bind within a site on the opposite face of the active site, and function as allosteric inhibitors. We also demonstrate that this class of compounds inhibits Eya2 phosphatase-mediated cell migration, setting the foundation for these molecules to be developed into chemical probes for understanding the specific function of the Eya2 phosphatase and to serve as a prototype for the development of Eya2 phosphatase specific anti-cancer drugs. PMID:24755226

  19. Discovery of a sulfamate-based steroid sulfatase inhibitor with intrinsic selective estrogen receptor modulator properties.

    PubMed

    Ouellet, Charles; Maltais, René; Ouellet, Étienne; Barbeau, Xavier; Lagüe, Patrick; Poirier, Donald

    2016-08-25

    Steroid sulfatase (STS), the enzyme which converts inactive sulfated steroid precursors into active hormones, is a promising therapeutic target for the treatment of estrogen-sensitive breast cancer. We report herein the synthesis and in vitro study of dual-action STS inhibitors with selective estrogen-receptor modulator (SERM) effects. A library of tetrahydroisoquinoline-N-substituted derivatives (phenolic compounds) was synthesized by solid-phase chemistry and tested on estrogen-sensitive breast cancer T-47D cells. Three phenolic compounds devoid of estrogenic activity and toxicity emerged from this screening. Their sulfamate analogs were then synthesized, tested in STS-transfected HEK-293 cells, and found to be potent inhibitors of the enzyme (IC50 of 3.9, 8.9, and 16.6 nM). When tested in T-47D cells they showed no estrogenic activity and produced a moderate antiestrogenic activity. The compounds were further tested on osteoblast-like Saos-2 cells and found to significantly stimulate their proliferation as well as their alkaline phosphatase activity, thus suggesting a SERM activity. These results are supported by molecular docking experiments. PMID:27155470

  20. Identification and Structure-Activity Relationships of Diarylhydrazides as Novel Potent and Selective Human Enterovirus Inhibitors.

    PubMed

    Han, Xin; Sun, Ningyuan; Wu, Haoming; Guo, Deyin; Tien, Po; Dong, Chune; Wu, Shuwen; Zhou, Hai-Bing

    2016-03-10

    Enterovirus 71 (EV71) plays an important role in hand-foot-and-mouth disease. In this study, a series of diarylhydrazide analogues was synthesized, and the systematic exploration of SAR led to potent enterovirus inhibitors, of which compound 15 exhibits significant improvements in inhibition potency with an EC50 value of 0.02 μM against EV71. It is very interesting that this class of diarylhydrazides exhibits activities against a series of human enteroviruses at the picomolar level, including EV71 and Coxsackieviruses B1 (CVB1), CVB2, CVB3, CVB4, CVB5, and CVB6 (EC50 as low as 0.5 nM). Compared with the reference antienterovirus drug 1 (enviroxime) and known inhibitor 5 (WIN 51711), the four highly selective compounds 15, 27, 41 and 47 inhibited EV71 replication with EC50 values of 0.17-0.02 μM and SI values in a range of 978.4-12338. A preliminary mechanistic study indicated that VP1 might be the target site for this type of compound. PMID:26885567

  1. Resveratrol-salicylate derivatives as selective DNMT3 inhibitors and anticancer agents.

    PubMed

    Aldawsari, Fahad S; Aguayo-Ortiz, Rodrigo; Kapilashrami, Kanishk; Yoo, Jakyung; Luo, Minkui; Medina-Franco, José L; Velázquez-Martínez, Carlos A

    2016-10-01

    Resveratrol is a natural polyphenol with plethora of biological activities. Resveratrol has previously shown to decrease DNA-methyltransferase (DNMT) enzymes expression and to reactivate silenced tumor suppressor genes. Currently, it seems that no resveratrol analogs have been developed as DNMT inhibitors. Recently, we reported the synthesis of resveratrol-salicylate derivatives and by examining the chemical structure of these analogs, we proposed that these compounds could exhibit DNMT inhibition especially that they resembled NSC 14778, a compound we previously identified as a DNMT inhibitor by virtual screening. Indeed, using in vitro DNMT inhibition assay, some of the resveratrol-salicylate analogs we screened in this work that showed selective inhibition against DNMT3 enzymes which were greater than resveratrol. A molecular docking study revealed key binding interactions with DNMT3A and DNMT3B enzymes. In addition, the most active analog, 10 showed considerable cytotoxicity against three human cancer cells; HT-29, HepG2 and SK-BR-3, which was greater than resveratrol. Further studies are needed to understand the anticancer mechanisms of these derivatives. PMID:26118420

  2. Selective cytotoxicity and telomere damage in leukemia cells using the telomerase inhibitor BIBR1532.

    PubMed

    El-Daly, Hesham; Kull, Miriam; Zimmermann, Stefan; Pantic, Milena; Waller, Cornelius F; Martens, Uwe M

    2005-02-15

    Telomerase represents an attractive target for a mechanism-based therapeutic approach because its activation has been associated with unlimited proliferation in most cancer cells. Recently, a nonnucleosidic small molecule inhibitor, BIBR1532 (2-[(E)-3-naphtalen-2-yl-but-2-enoylamino]-benzoic acid), has been identified that is highly selective for inhibition of telomerase, resulting in delayed growth arrest of tumor cells. Here we examined the effects of BIBR1532 in different leukemia cell lines as well as in primary cells from patients with acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) in short-term culture assays. We observed a dose-dependent direct cytotoxicity in concentrations ranging from 30 to 80 microM. Interestingly, cell death was not dependent on the catalytic activity of telomerase but was delayed in cells with very long telomeres. We observed time-dependent individual telomere erosion, which was associated with loss of telomeric repeat binding factor 2 (TRF2) and increased phosphorylation of p53. Importantly, the proliferative capacity of normal CD34(+) cells from cord blood and leukapheresis samples was not affected by treatment with BIBR1532. We conclude that using this class of telomerase inhibitor at higher concentrations exerts a direct cytotoxic effect on malignant cells of the hematopoietic system, which appears to derive from direct damage of the structure of individual telomeres and must be dissected from telomerase-suppressed overall telomere shortening. PMID:15507522

  3. RVX-297- a novel BD2 selective inhibitor of BET bromodomains.

    PubMed

    Kharenko, Olesya A; Gesner, Emily M; Patel, Reena G; Norek, Karen; White, Andre; Fontano, Eric; Suto, Robert K; Young, Peter R; McLure, Kevin G; Hansen, Henrik C

    2016-08-12

    Bromodomains are epigenetic readers that specifically bind to the acetyl lysine residues of histones and transcription factors. Small molecule BET bromodomain inhibitors can disrupt this interaction which leads to potential modulation of several disease states. Here we describe the binding properties of a novel BET inhibitor RVX-297 that is structurally related to the clinical compound RVX-208, currently undergoing phase III clinical trials for the treatment of cardiovascular diseases, but is distinctly different in its biological and pharmacokinetic profiles. We report that RVX-297 preferentially binds to the BD2 domains of the BET bromodomain and Extra Terminal (BET) family of protein. We demonstrate the differential binding modes of RVX-297 in BD1 and BD2 domains of BRD4 and BRD2 using X-ray crystallography, and describe the structural differences driving the BD2 selective binding of RVX-297. The isothermal titration calorimetry (ITC) data illustrate the related differential thermodynamics of binding of RVX-297 to single as well as dual BET bromodomains. PMID:27282480

  4. Pyrimidinone nicotinamide mimetics as selective tankyrase and wnt pathway inhibitors suitable for in vivo pharmacology.

    PubMed

    Johannes, Jeffrey W; Almeida, Lynsie; Barlaam, Bernard; Boriack-Sjodin, P Ann; Casella, Robert; Croft, Rosemary A; Dishington, Allan P; Gingipalli, Lakshmaiah; Gu, Chungang; Hawkins, Janet L; Holmes, Jane L; Howard, Tina; Huang, Jian; Ioannidis, Stephanos; Kazmirski, Steven; Lamb, Michelle L; McGuire, Thomas M; Moore, Jane E; Ogg, Derek; Patel, Anil; Pike, Kurt G; Pontz, Timothy; Robb, Graeme R; Su, Nancy; Wang, Haiyun; Wu, Xiaoyun; Zhang, Hai-Jun; Zhang, Yue; Zheng, Xiaolan; Wang, Tao

    2015-03-12

    The canonical Wnt pathway plays an important role in embryonic development, adult tissue homeostasis, and cancer. Germline mutations of several Wnt pathway components, such as Axin, APC, and ß-catenin, can lead to oncogenesis. Inhibition of the poly(ADP-ribose) polymerase (PARP) catalytic domain of the tankyrases (TNKS1 and TNKS2) is known to inhibit the Wnt pathway via increased stabilization of Axin. In order to explore the consequences of tankyrase and Wnt pathway inhibition in preclinical models of cancer and its impact on normal tissue, we sought a small molecule inhibitor of TNKS1/2 with suitable physicochemical properties and pharmacokinetics for hypothesis testing in vivo. Starting from a 2-phenyl quinazolinone hit (compound 1), we discovered the pyrrolopyrimidinone compound 25 (AZ6102), which is a potent TNKS1/2 inhibitor that has 100-fold selectivity against other PARP family enzymes and shows 5 nM Wnt pathway inhibition in DLD-1 cells. Moreover, compound 25 can be formulated well in a clinically relevant intravenous solution at 20 mg/mL, has demonstrated good pharmacokinetics in preclinical species, and shows low Caco2 efflux to avoid possible tumor resistance mechanisms. PMID:25815142

  5. Pyrimidinone Nicotinamide Mimetics as Selective Tankyrase and Wnt Pathway Inhibitors Suitable for in Vivo Pharmacology

    PubMed Central

    2015-01-01

    The canonical Wnt pathway plays an important role in embryonic development, adult tissue homeostasis, and cancer. Germline mutations of several Wnt pathway components, such as Axin, APC, and ß-catenin, can lead to oncogenesis. Inhibition of the poly(ADP-ribose) polymerase (PARP) catalytic domain of the tankyrases (TNKS1 and TNKS2) is known to inhibit the Wnt pathway via increased stabilization of Axin. In order to explore the consequences of tankyrase and Wnt pathway inhibition in preclinical models of cancer and its impact on normal tissue, we sought a small molecule inhibitor of TNKS1/2 with suitable physicochemical properties and pharmacokinetics for hypothesis testing in vivo. Starting from a 2-phenyl quinazolinone hit (compound 1), we discovered the pyrrolopyrimidinone compound 25 (AZ6102), which is a potent TNKS1/2 inhibitor that has 100-fold selectivity against other PARP family enzymes and shows 5 nM Wnt pathway inhibition in DLD-1 cells. Moreover, compound 25 can be formulated well in a clinically relevant intravenous solution at 20 mg/mL, has demonstrated good pharmacokinetics in preclinical species, and shows low Caco2 efflux to avoid possible tumor resistance mechanisms. PMID:25815142

  6. PFI-1 – A highly Selective Protein Interaction Inhibitor Targeting BET Bromodomains

    PubMed Central

    Picaud, Sarah; Costa, David Da; Thanasopoulou, Angeliki; Filippakopoulos, Panagis; Fish, Paul V.; Philpott, Martin; Fedorov, Oleg; Brennan, Paul; Bunnage, Mark E.; Owen, Dafydd R.; Bradner, James E.; Taniere, Philippe; O’Sullivan, Brendan; Müller, Susanne; Schwaller, Juerg; Stankovic, Tatjana; Knapp, Stefan

    2013-01-01

    Bromo and extra terminal (BET) proteins (BRD2, BRD3, BRD4 and BRDT) are transcriptional regulators required for efficient expression of several growth promoting and anti-apoptotic genes as well as for cell cycle progression. BET proteins are recruited to transcriptionally active chromatin via their two N-terminal bromodomains (BRDs), a protein interaction module that specifically recognizes acetylated lysine residues in histones H3 and H4. Inhibition of the BET-histone interaction results in transcriptional down-regulation of a number of oncogenes providing a novel pharmacological strategy for the treatment of cancer. Here we present a potent and highly selective dihydroquinazoline-2-one inhibitor, PFI-1 that efficiently blocks the interaction of BET BRDs with acetylated histone tails. Co-crystal structures showed that PFI-1 acts as an acetyl-lysine (Kac) mimetic inhibitor efficiently occupying the Kac binding site in BRD4 and BRD2. PFI-1 has antiproliferative effects on leukaemic cell lines and efficiently abrogates their clonogenic growth. Exposure of sensitive cell lines with PFI-1 results in G1 cell cycle arrest, down-regulation of MYC expression as well as induction of apoptosis and induces differentiation of primary leukaemic blasts. Intriguingly, cells exposed to PFI-1 showed significant down-regulation of Aurora B kinase, thus attenuating phosphorylation of the Aurora substrate H3S10 providing an alternative strategy for the specific inhibition of this well established oncology target. PMID:23576556

  7. Neuroprotective effect of selective DPP-4 inhibitor in experimental vascular dementia.

    PubMed

    Jain, Swati; Sharma, Bhupesh

    2015-12-01

    Vascular risk factors are associated with a higher incidence of dementia. Diabetes mellitus is considered as a main risk factor for Alzheimer's disease and vascular dementia. Both forms of dementia are posing greater risk to the world population and are increasing at a faster rate. In the past we have reported the induction of vascular dementia by experimental diabetes. This study investigates the role of vildagliptin, a dipeptidyl peptidase-4 inhibitor in the pharmacological interdiction of pancreatectomy diabetes induced vascular endothelial dysfunction and subsequent vascular dementia in rats. Attentional set shifting and Morris water-maze test were used for assessment of learning and memory. Vascular endothelial function, blood brain barrier permeability, serum glucose, serum nitrite/nitrate, oxidative stress (viz. aortic superoxide anion, brain thiobarbituric acid reactive species and brain glutathione), brain calcium and inflammation (myeloperoxidase) were also estimated. Pancreatectomy diabetes rats have shown impairment of endothelial function, blood brain barrier permeability, learning and memory along with increase in brain inflammation, oxidative stress and calcium. Administration of vildagliptin has significantly attenuated pancreatectomy induced impairment of learning, memory, endothelial function, blood brain barrier permeability and biochemical parameters. It may be concluded that vildagliptin, a dipeptidyl peptidase-4 inhibitor may be considered as potential pharmacological agents for the management of pancreatectomy induced endothelial dysfunction and subsequent vascular dementia. The selective modulators of dipeptidyl peptidase-4 may further be explored for their possible benefits in vascular dementia. PMID:26382939

  8. Potent and selective fluoroketone inhibitors of group VIA calcium-independent phospholipase A2.

    PubMed

    Kokotos, George; Hsu, Yuan-Hao; Burke, John E; Baskakis, Constantinos; Kokotos, Christoforos G; Magrioti, Victoria; Dennis, Edward A

    2010-05-13

    Group VIA calcium-independent phospholipase A(2) (GVIA iPLA(2)) has recently emerged as a novel pharmaceutical target. We have now explored the structure-activity relationship between fluoroketones and GVIA iPLA(2) inhibition. The presence of a naphthyl group proved to be of paramount importance. 1,1,1-Trifluoro-6-(naphthalen-2-yl)hexan-2-one (FKGK18) is the most potent inhibitor of GVIA iPLA(2) (X(I)(50) = 0.0002) ever reported. Being 195 and >455 times more potent for GVIA iPLA(2) than for GIVA cPLA(2) and GV sPLA(2), respectively, makes it a valuable tool to explore the role of GVIA iPLA(2) in cells and in vivo models. 1,1,1,2,2,3,3-Heptafluoro-8-(naphthalene-2-yl)octan-4-one inhibited GVIA iPLA(2) with a X(I)(50) value of 0.001 while inhibiting the other intracellular GIVA cPLA(2) and GV sPLA(2) at least 90 times less potently. Hexa- and octafluoro ketones were also found to be potent inhibitors of GVIA iPLA(2); however, they are not selective. PMID:20369880

  9. Potent and Selective Fluoroketone Inhibitors of Group VIA Calcium-Independent Phospholipase A2

    PubMed Central

    Kokotos, George; Hsu, Yuan-Hao; Burke, John E.; Baskakis, Constantinos; Kokotos, Christoforos G.; Magrioti, Victoria; Dennis, Edward A.

    2010-01-01

    Group VIA calcium-independent phospholipase A2 (GVIA iPLA2) has recently emerged as a novel pharmaceutical target. We have now explored the structure-activity relationship between fluoroketones and GVIA iPLA2 inhibition. The presence of a naphthyl group proved to be of paramount importance. 1,1,1-Trifluoro-6-(naphthalen-2-yl)hexan-2-one (FKGK18) is the most potent inhibitor of GVIA iPLA2 (XI(50) 0.0002) ever reported. Being 195 and >455 times more potent for GVIA iPLA2 than for GIVA cPLA2 and GV sPLA2, respectively, makes it a valuable tool to explore the role of GVIA iPLA2 in cells and in vivo models. 1,1,1,2,2,3,3-Heptafluoro-8-(naphthalene-2-yl) octan-4-one inhibited GVIA iPLA2 with a XI(50) value of 0.001, while inhibiting the other intracellular GIVA cPLA2 and GV sPLA2 at least 90-times less potently. Hexa- and octa-fluoro ketones were also found to be potent inhibitors of GVIA iPLA2; however they are not selective. PMID:20369880

  10. Activated Drosophila Ras1 is selectively suppressed by isoprenyl transferase inhibitors.

    PubMed Central

    Kauffmann, R C; Qian, Y; Vogt, A; Sebti, S M; Hamilton, A D; Carthew, R W

    1995-01-01

    Ras CAAX (C = cysteine, A = aliphatic amino acid, and X = any amino acid) peptidomimetic inhibitors of farnesyl protein transferase suppress Ras-dependent cell transformation by preventing farnesylation of the Ras oncoprotein. These compounds are potential anticancer agents for tumors associated with Ras mutations. The peptidomimetic FTI-254 was tested for Ras1-inhibiting activity in whole animals by injection of activated Ras1val12 Drosophila larvae. FTI-254 decreased the ability of Ras1val12 to form supernumerary R7 photoreceptor cells in the compound eye of transformed flies. In contrast, it had no effect on the related supernumerary R7 phenotypes of flies transformed with either the activated sevenless receptor tyrosine kinase, Raf kinase, or a chimeric Ras1val12 protein that is membrane associated through myristylation instead of isoprenylation. Therefore, FTI-254 acts as an isoprenylation inhibitor to selectively inhibit Ras1val12 signaling activity in a whole-animal model system. Images Fig. 2 PMID:7479910

  11. Selective CNS Uptake of the GCP-II Inhibitor 2-PMPA following Intranasal Administration.

    PubMed

    Rais, Rana; Wozniak, Krystyna; Wu, Ying; Niwa, Minae; Stathis, Marigo; Alt, Jesse; Giroux, Marc; Sawa, Akira; Rojas, Camilo; Slusher, Barbara S

    2015-01-01

    Glutamate carboxypeptidase II (GCP-II) is a brain metallopeptidase that hydrolyzes the abundant neuropeptide N-acetyl-aspartyl-glutamate (NAAG) to NAA and glutamate. Small molecule GCP-II inhibitors increase brain NAAG, which activates mGluR3, decreases glutamate, and provide therapeutic utility in a variety of preclinical models of neurodegenerative diseases wherein excess glutamate is presumed pathogenic. Unfortunately no GCP-II inhibitor has advanced clinically, largely due to their highly polar nature resulting in insufficient oral bioavailability and limited brain penetration. Herein we report a non-invasive route for delivery of GCP-II inhibitors to the brain via intranasal (i.n.) administration. Three structurally distinct classes of GCP-II inhibitors were evaluated including DCMC (urea-based), 2-MPPA (thiol-based) and 2-PMPA (phosphonate-based). While all showed some brain penetration following i.n. administration, 2-PMPA exhibited the highest levels and was chosen for further evaluation. Compared to intraperitoneal (i.p.) administration, equivalent doses of i.n. administered 2-PMPA resulted in similar plasma exposures (AUC0-t, i.n./AUC0-t, i.p. = 1.0) but dramatically enhanced brain exposures in the olfactory bulb (AUC0-t, i.n./AUC0-t, i.p. = 67), cortex (AUC0-t, i.n./AUC0-t, i.p. = 46) and cerebellum (AUC0-t, i.n./AUC0-t, i.p. = 6.3). Following i.n. administration, the brain tissue to plasma ratio based on AUC0-t in the olfactory bulb, cortex, and cerebellum were 1.49, 0.71 and 0.10, respectively, compared to an i.p. brain tissue to plasma ratio of less than 0.02 in all areas. Furthermore, i.n. administration of 2-PMPA resulted in complete inhibition of brain GCP-II enzymatic activity ex-vivo confirming target engagement. Lastly, because the rodent nasal system is not similar to humans, we evaluated i.n. 2-PMPA also in a non-human primate. We report that i.n. 2-PMPA provides selective brain delivery with micromolar concentrations. These studies support

  12. Selective CNS Uptake of the GCP-II Inhibitor 2-PMPA following Intranasal Administration

    PubMed Central

    Rais, Rana; Wozniak, Krystyna; Wu, Ying; Niwa, Minae; Stathis, Marigo; Alt, Jesse; Giroux, Marc; Sawa, Akira; Rojas, Camilo; Slusher, Barbara S.

    2015-01-01

    Glutamate carboxypeptidase II (GCP-II) is a brain metallopeptidase that hydrolyzes the abundant neuropeptide N-acetyl-aspartyl-glutamate (NAAG) to NAA and glutamate. Small molecule GCP-II inhibitors increase brain NAAG, which activates mGluR3, decreases glutamate, and provide therapeutic utility in a variety of preclinical models of neurodegenerative diseases wherein excess glutamate is presumed pathogenic. Unfortunately no GCP-II inhibitor has advanced clinically, largely due to their highly polar nature resulting in insufficient oral bioavailability and limited brain penetration. Herein we report a non-invasive route for delivery of GCP-II inhibitors to the brain via intranasal (i.n.) administration. Three structurally distinct classes of GCP-II inhibitors were evaluated including DCMC (urea-based), 2-MPPA (thiol-based) and 2-PMPA (phosphonate-based). While all showed some brain penetration following i.n. administration, 2-PMPA exhibited the highest levels and was chosen for further evaluation. Compared to intraperitoneal (i.p.) administration, equivalent doses of i.n. administered 2-PMPA resulted in similar plasma exposures (AUC0-t, i.n./AUC0-t, i.p. = 1.0) but dramatically enhanced brain exposures in the olfactory bulb (AUC0-t, i.n./AUC0-t, i.p. = 67), cortex (AUC0-t, i.n./AUC0-t, i.p. = 46) and cerebellum (AUC0-t, i.n./AUC0-t, i.p. = 6.3). Following i.n. administration, the brain tissue to plasma ratio based on AUC0-t in the olfactory bulb, cortex, and cerebellum were 1.49, 0.71 and 0.10, respectively, compared to an i.p. brain tissue to plasma ratio of less than 0.02 in all areas. Furthermore, i.n. administration of 2-PMPA resulted in complete inhibition of brain GCP-II enzymatic activity ex-vivo confirming target engagement. Lastly, because the rodent nasal system is not similar to humans, we evaluated i.n. 2-PMPA also in a non-human primate. We report that i.n. 2-PMPA provides selective brain delivery with micromolar concentrations. These studies support

  13. Acetylcholinesterase capillary enzyme reactor for screening and characterization of selective inhibitors.

    PubMed

    da Silva, Joyce Izidoro; de Moraes, Marcela Cristina; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalves; Cass, Quezia Bezerra; Cardoso, Carmen Lucia

    2013-01-25

    The aim of the present work is to report on the optimized preparation of capillary enzyme reactors (ICERs) based on acetylcholinesterase (AChE, EC 3.1.1.7), for the screening of selective inhibitors. The AChE-ICERs were prepared by using the homobifunctional linker glutaraldehyde through Schiff base linkage. The enzyme was anchored onto a modified fused silica capillary and employed as an LC biochromatography column for online studies, with UV-vis detection. Not only did the tailored AChE-ICER result in maintenance of the activity of the immobilized enzyme, but it also significantly improved the stability of the enzyme in the presence of organic solvents. In addition, the kinetic studies demonstrated that the enzyme retained its activity with high stability, preserving its initial activity over 10months. The absence of non-specific matrix interactions, immediate recovery of the enzymatic activity, and short analysis time were the main advantages of this AChE-ICER. The use of AChE-ICER in the ligands recognition assay was validated by evaluation of four known reversible inhibitors (galanthamine, tacrine, propidium, and rivastigmine), and the same order of inhibitory potencies described in the literature was found. The immobilized enzyme was utilized in the screening of 21 coumarin derivatives. In this library, two new potent inhibitors were identified: coumarins 20 (IC(50) 17.14±3.50μM) and 21 (IC(50) 6.35±1.20μM), which were compared to the standard galanthamine (IC(50) 12.68±2.40μM). Considering the high inhibitory activities of these compounds, with respect to the AChE-ICER, the mechanism of action was investigated. Both coumarins 20 and 21 exhibited a competitive mechanism of action, furnishing K(i) values of 8.04±0.18 and 2.67±0.18μM, respectively. The results revealed that the AChE-ICER developed herein represents a useful tool for the biological screening of inhibitor candidates and evaluation of action mechanism. PMID:22391555

  14. Dapoxetine, a novel selective serotonin transport inhibitor for the treatment of premature ejaculation

    PubMed Central

    Kendirci, Muammer; Salem, Emad; Hellstrom, Wayne JG

    2007-01-01

    Premature ejaculation (PE) is the most common male sexual disorder, estimated to affect up to 30% of men. Over the past one or two decades, clinical investigators have participated in an increasing number of studies that are helping in our understanding of PE, which will undoubtedly facilitate future treatments. Apart from a number of behavioral approaches, the treatment of PE consists of primarily off-label use of oral selective serotonin reuptake inhibitors (SSRIs) via either on-demand or daily delivery. However, various undesirable side-effects of these medications have led researchers to search for and develop new therapeutic approaches for PE. Dapoxetine is a short-acting SSRI developed specifically for the treatment of PE. Early trials with dapoxetine have documented successful outcomes without serious short- or long-term side-effects. This review addresses the definition, classification, diagnosis, physiology, and neurobiopathology of PE, and evaluates therapeutic strategies with novel treatments for PE. PMID:18360636

  15. Design, Synthesis and Biological Evaluation of Novel Benzothiazole Derivatives as Selective PI3Kβ Inhibitors.

    PubMed

    Cao, Shuang; Cao, Ruiyuan; Liu, Xialing; Luo, Xiang; Zhong, Wu

    2016-01-01

    A novel series of PI3Kβ (Phosphatidylinositol-3-kinases beta subunit) inhibitors with the structure of benzothiazole scaffold have been designed and synthesized. All the compounds have been evaluated for inhibitory activities against PI3Kα, β, γ, δ and mTOR (Mammalian target of rapamycin). Two superior compounds have been further evaluated for the IC50 values against PI3Ks/mTOR. The most promising compound 11 displays excellent anti-proliferative activity and selectivity in multiple cancer cell lines, especially in the prostate cancer cell line. Docking studies indicate the morpholine group in 2-position of benzothiazole is necessary for the potent antitumor activity, which confirms our design is reasonable. PMID:27384552

  16. Fatal serotonin syndrome precipitated by oxcarbazepine in a patient using an selective serotonin reuptake inhibitor.

    PubMed

    Dardis, Christopher; Omoregie, Eghosa; Ly, Vanthanh

    2012-07-01

    Oxcarbazepine, a metabolite of carbamazepine, is used as an antiepileptic, analgesic for neuropathic pain and in the treatment of affective disorders. It has been approved by the Food and Drug Administration for partial seizures in adults as both adjunctive and monotherapy, and as adjunctive therapy in children aged from 2 to 16 years (http://www.fda.gov/ohrms/dockets/ac/06/briefing/2006-4254b_07_05_KP%20OxcarbazepineFDAlabel102005.pdf). We present a case of serotonin syndrome, which was precipitated by this medicine in a patient who had been predisposed by long-term treatment with sertraline, a selective serotonin reuptake inhibitor. This is the first reported fatality due to this drug interaction and only the second case of serotonin syndrome reported with oxcarbazepine. Physicians should consider this risk when prescribing the above combination. PMID:22735246

  17. Pyrrolidinobenzoic Acid Inhibitors of Influenza Virus Neuraminidase: the Hydrophobic Side Chain Influences Type A Subtype Selectivity

    PubMed Central

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M.

    2012-01-01

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 vs N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  18. Pyrrolidinobenzoic acid inhibitors of influenza virus neuraminidase: the hydrophobic side chain influences type A subtype selectivity.

    PubMed

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M; Brouillette, Wayne J

    2012-07-15

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 versus N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  19. Is the cardiovascular toxicity of NSAIDS and COX-2 selective inhibitors underestimated in patients with haemophilia?

    PubMed

    Boban, Ana; Lambert, Catherine; Hermans, Cedric

    2016-04-01

    Joint pain secondary to chronic arthropathy represents one of the most common and debilitating complications of haemophilia, often requiring analgesic care. When compared with nonselective non-steroidal anti-inflammatory drugs (ns-NSAIDs), selective COX-2 inhibitors (coxibs) offer the major advantage of not increasing the bleeding risk, thus being a better choice of analgesics for haemophilia patients. However, several studies have highlighted the cardiovascular risks posed by coxibs and NSAIDs. Given the assumed protection against thrombosis conferred by the deficiency in coagulation factors VIII or IX, these precautions regarding the use of coxibs and NSAIDs have never really been taken into account in haemophilia management. However, contrary to what has long been suspected, haemophilia patients are indeed affected by the same cardiovascular risk factors as nonhaemophiliac patients. Further studies should be conducted to evaluate the impact of NSAIDs on cardiovascular risks and the prevalence of hypertension in haemophilia patients. PMID:26899022

  20. Delayed pressure urticaria treated with the selective serotonin reuptake inhibitor escitalopram.

    PubMed

    Eskeland, S; Tanum, L; Halvorsen, J A

    2016-07-01

    There is increasing evidence of platelet activation and systemic inflammation in chronic spontaneous urticaria and delayed pressure urticaria (DPU). Inflammation may be central to understanding the high comorbidity of depression and anxiety in patients with chronic urticaria (CU). We report a case of DPU and depression in a patient, which responded favourably to treatment with the selective serotonin reuptake inhibitor (SSRI) escitalopram. Sustained administration of SSRIs is associated with downregulation of serotonin transporters/receptors and depletion of platelet stored serotonin, which may reduce the ability of platelets to aggregate after thrombotic triggers. SSRIs are easier to manage and have significantly less disturbing adverse effects and cardiotoxicity than the tricyclic antidepressants (TCAs). SSRIs may represent an alternative to the traditional use of TCAs in treatment of CU. PMID:27037523

  1. Structure-Based Design of a Novel Series of Potent, Selective Inhibitors of the Class I Phosphatidylinositol 3-Kinases

    SciTech Connect

    Smith, Adrian L.; D’Angelo, Noel D.; Bo, Yunxin Y.; Booker, Shon K.; Cee, Victor J.; Herberich, Brad; Hong, Fang-Tsao; Jackson, Claire L.M.; Lanman, Brian A.; Liu, Longbin; Nishimura, Nobuko; Pettus, Liping H.; Reed, Anthony B.; Tadesse, Seifu; Tamayo, Nuria A.; Wurz, Ryan P.; Yang, Kevin; Andrews, Kristin L.; Whittington, Douglas A.; McCarter, John D.; Miguel, Tisha San; Zalameda, Leeanne; Jiang, Jian; Subramanian, Raju; Mullady, Erin L.; Caenepeel, Sean; Freeman, Daniel J.; Wang, Ling; Zhang, Nancy; Wu, Tian; Hughes, Paul E.; Norman, Mark H.

    2012-09-17

    A highly selective series of inhibitors of the class I phosphatidylinositol 3-kinases (PI3Ks) has been designed and synthesized. Starting from the dual PI3K/mTOR inhibitor 5, a structure-based approach was used to improve potency and selectivity, resulting in the identification of 54 as a potent inhibitor of the class I PI3Ks with excellent selectivity over mTOR, related phosphatidylinositol kinases, and a broad panel of protein kinases. Compound 54 demonstrated a robust PD-PK relationship inhibiting the PI3K/Akt pathway in vivo in a mouse model, and it potently inhibited tumor growth in a U-87 MG xenograft model with an activated PI3K/Akt pathway.

  2. Structure-guided design of a selective BCL-X(L) inhibitor.

    PubMed

    Lessene, Guillaume; Czabotar, Peter E; Sleebs, Brad E; Zobel, Kerry; Lowes, Kym N; Adams, Jerry M; Baell, Jonathan B; Colman, Peter M; Deshayes, Kurt; Fairbrother, Wayne J; Flygare, John A; Gibbons, Paul; Kersten, Wilhelmus J A; Kulasegaram, Sanji; Moss, Rebecca M; Parisot, John P; Smith, Brian J; Street, Ian P; Yang, Hong; Huang, David C S; Watson, Keith G

    2013-06-01

    The prosurvival BCL-2 family protein BCL-X(L) is often overexpressed in solid tumors and renders malignant tumor cells resistant to anticancer therapeutics. Enhancing apoptotic responses by inhibiting BCL-X(L) will most likely have widespread utility in cancer treatment and, instead of inhibiting multiple prosurvival BCL-2 family members, a BCL-X(L)-selective inhibitor would be expected to minimize the toxicity to normal tissues. We describe the use of a high-throughput screen to discover a new series of small molecules targeting BCL-X(L) and their structure-guided development by medicinal chemistry. The optimized compound, WEHI-539 (7), has high affinity (subnanomolar) and selectivity for BCL-X(L) and potently kills cells by selectively antagonizing its prosurvival activity. WEHI-539 will be an invaluable tool for distinguishing the roles of BCL-X(L) from those of its prosurvival relatives, both in normal cells and notably in malignant tumor cells, many of which may prove to rely upon BCL-X(L) for their sustained growth. PMID:23603658

  3. Selective overproduction of the proteasome inhibitor salinosporamide A via precursor pathway regulation

    PubMed Central

    Lechner, Anna; Eustáquio, Alessandra S.; Gulder, Tobias A. M.; Hafner, Mathias; Moore, Bradley S.

    2011-01-01

    The chlorinated natural product salinosporamide A is a potent 20S proteasome inhibitor currently in clinical trials as an anticancer agent. To deepen our understanding of salinosporamide biosynthesis, we investigated the function of a LuxR-type pathway-specific regulatory gene, salR2, and observed a selective effect on the production of salinosporamide A over its less active aliphatic analogs. SalR2 was shown to specifically activate genes involved in the biosynthesis of the halogenated precursor chloroethylmalonyl-CoA, which is a dedicated precursor of salinosporamide A. Specifically, SalR2 activates transcription of two divergent operons – one of which contains the unique S-adenosyl-L-methionine-dependent chlorinase encoding gene salL. By applying this knowledge towards rational engineering, we were able to selectively double salinosporamide A production. This study exemplifies the specialized regulation of a polyketide precursor pathway and its application to the selective overproduction of a specific natural product congener. PMID:22195555

  4. Structure-Based Design of β5c Selective Inhibitors of Human Constitutive Proteasomes.

    PubMed

    Xin, Bo-Tao; de Bruin, Gerjan; Huber, Eva M; Besse, Andrej; Florea, Bogdan I; Filippov, Dmitri V; van der Marel, Gijsbert A; Kisselev, Alexei F; van der Stelt, Mario; Driessen, Christoph; Groll, Michael; Overkleeft, Herman S

    2016-08-11

    This work reports the development of highly potent and selective inhibitors of the β5c catalytic activity of human constitutive proteasomes. The work describes the design principles, large hydrophobic P3 residue and small hydrophobic P1 residue, that led to the synthesis of a panel of peptide epoxyketones; their evaluation and the selection of the most promising compounds for further analyses. Structure-activity relationships detail how in a logical order the β1c/i, β2c/i, and β5i activities became resistant to inhibition as compounds were diversified stepwise. The most effective compounds were obtained as a mixture of cis- and trans-biscyclohexyl isomers, and enantioselective synthesis resolved this issue. Studies on yeast proteasome structures complexed with some of the compounds provide a rationale for the potency and specificity. Substitution of the N-terminus in the most potent compound for a more soluble equivalent led to a cell-permeable molecule that selectively and efficiently blocks β5c in cells expressing both constitutive proteasomes and immunoproteasomes. PMID:27438186

  5. Characterization and preclinical development of LY2603618: a selective and potent Chk1 inhibitor.

    PubMed

    King, Constance; Diaz, Henry; Barnard, Darlene; Barda, David; Clawson, David; Blosser, Wayne; Cox, Karen; Guo, Sherry; Marshall, Mark

    2014-04-01

    Interference with DNA damage checkpoints has been demonstrated preclinically to be a highly effective means of increasing the cytotoxicity of a number of DNA-damaging cancer therapies. Cell cycle arrest at these checkpoints protects injured cells from apoptotic cell death until DNA damage can be repaired. In the absence of functioning DNA damage checkpoints, cells with damaged DNA may proceed into premature mitosis followed by cell death. A key protein kinase involved in activating and maintaining the S and G2/M checkpoints is Chk1. Pharmacological inhibition of Chk1 in the absence of p53 functionality leads to abrogation of DNA damage checkpoints and has been shown preclinically to enhance the activity of many standard of care chemotherapeutic agents. LY2603618 is a potent and selective small molecule inhibitor of Chk1 protein kinase activity in vitro (IC(50) = 7 nM) and the first selective Chk1 inhibitor to enter clinical cancer trials. Treatment of cells with LY2603618 produced a cellular phenotype similar to that reported for depletion of Chk1 by RNAi. Inhibition of intracellular Chk1 by LY2603618 results in impaired DNA synthesis, elevated H2A.X phosphorylation indicative of DNA damage and premature entry into mitosis. When HeLa cells were exposed to doxorubicin to induce a G2/M checkpoint arrest, subsequent treatment with LY2603618 released the checkpoint, resulting in cells entering into metaphase with poorly condensed chromosomes. Consistent with abrogation of the Chk1 and p53-dependent G2/M checkpoint, mutant TP53 HT-29 colon cancer cells were more sensitive to gemcitabine when also treated with LY2603618, while wild-type TP53 HCT116 cells were not sensitized by LY2603618 to gemcitabine. Treatment of Calu-6 human mutant TP53 lung cancer cell xenografts with gemcitabine resulted in a stimulation of Chk1 kinase activity that was inhibited by co-administration of LY2603618. By all criteria, LY2603618 is a highly effective inhibitor of multiple aspects of

  6. The pharmacology of sildenafil, a novel and selective inhibitor of phosphodiesterase (PDE) type 5.

    PubMed

    Wallis, R M

    1999-10-01

    Sildenafil (1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4,3-d]pyrimidin-5-yl) phenylsulphonyl]-4-methylpiperazine) has been shown to be an effective oral treatment for male erectile dysfunction. Sildenafil is a potent competitive inhibitor of PDE5 (IC50 3.5 nM) and is selective over PDE1 to 4 (80 to 19,000-fold) and retinal PDE6 (10-fold). Sildenafil enhanced cGMP accumulation driven with sodium nitroprusside in the corpus cavernosum of rabbits without affecting cAMP formulation. In the absence of nitric oxide drive, sildenafil had no functional effect on the human and rabbit isolated corpus cavernosum, but potently potentiated the relaxant effects of nitric oxide on these tissues. In the anaesthetised dog, sildenafil (ED50: 12 to 16 micrograms/kg i.v.) enhanced the increase in intracavernosal pressure induced by electrical stimulation of the pelvic nerve or intracavernosal injection of sodium nitroprusside in the absence of meaningful effects on blood pressure. Consistent with its mode of action, sildenafil potentiated the vasorelaxant effects of glyceryl trinitrate on rabbit isolated aortic rings. However, unlike milrinone, sildenafil had no inotropic effects on the dog isolated trabeculae carneae. Thus it is unlikely to have the deleterious effects on cardiac function associated with PDE3 inhibitors. As a consequence of inhibition of PDE6 in the retina, sildenafil (1 to 100 microM) altered the kinetics of the light response of the dog isolated retina. In the anaesthetised dog, sildenafil modified the a- and b-wave of the electroretinogram induced by a flash of blue light. These effects were proportional to plasma concentrations, were fully reversible and only occurred following plasma concentrations higher (approximately 30-fold) than those active on intracavernosal pressure. These studies have shown that sildenafil is a potent and selective inhibitor of PDE5. It enhances the effect of nitric oxide on the corpus cavernosum and has been shown

  7. Discovery of 7-aminofuro[2,3-c]pyridine inhibitors of TAK1: optimization of kinase selectivity and pharmacokinetics.

    PubMed

    Hornberger, Keith R; Chen, Xin; Crew, Andrew P; Kleinberg, Andrew; Ma, Lifu; Mulvihill, Mark J; Wang, Jing; Wilde, Victoria L; Albertella, Mark; Bittner, Mark; Cooke, Andrew; Kadhim, Salam; Kahler, Jennifer; Maresca, Paul; May, Earl; Meyn, Peter; Romashko, Darlene; Tokar, Brianna; Turton, Roy

    2013-08-15

    The kinase selectivity and pharmacokinetic optimization of a series of 7-aminofuro[2,3-c]pyridine inhibitors of TAK1 is described. The intersection of insights from molecular modeling, computational prediction of metabolic sites, and in vitro metabolite identification studies resulted in a simple and unique solution to both of these problems. These efforts culminated in the discovery of compound 13a, a potent, relatively selective inhibitor of TAK1 with good pharmacokinetic properties in mice, which was active in an in vivo model of ovarian cancer. PMID:23856049

  8. Discovery and Structure-Activity Relationships of a Highly Selective Butyrylcholinesterase Inhibitor by Structure-Based Virtual Screening.

    PubMed

    Dighe, Satish N; Deora, Girdhar Singh; De la Mora, Eugenio; Nachon, Florian; Chan, Stephen; Parat, Marie-Odile; Brazzolotto, Xavier; Ross, Benjamin P

    2016-08-25

    Structure-based virtual screening of two libraries containing 567 981 molecules was used to discover novel, selective BuChE inhibitors, which are potentially superior symptomatic treatments in late-stage Alzheimer's disease. Compound 16 was identified as a highly selective submicromolar inhibitor of BuChE (huBuChE IC50 = 0.443 μM) with high permeability in the PAMPA-BBB model. The X-ray crystal structure of huBuChE in complex with 16 revealed the atomic-level interactions and offers opportunities for further development of the series. PMID:27405689

  9. Using cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography to determine selective serotonin reuptake inhibitors.

    PubMed

    Su, Hsiu-Li; Hsieh, You-Zung

    2008-10-31

    We have employed a rapid and highly efficient on-line preconcentration method, cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI-sweeping-MEKC), for the analysis of selective serotonin reuptake inhibitors (SSRIs) of antidepressant drugs. We monitored the effects of several of the CSEI-sweeping-MEKC parameters - including the pH, the concentrations of high-conductivity buffer (HCB), sodium dodecyl sulfate (SDS), and organic modifier, the injection length of the HCB, and the injection time of the sample - to optimize the separation process. The optimal background electrolyte was 50 mM citric acid/disodium hydrogenphosphate buffer (pH 2.2) containing 100 mM SDS and 22% isopropyl alcohol. The sensitivity enhancements of the SSRIs sertraline, fluoxetine, paroxetine, fluvoxamine, and citalopram ranged from 5.7 x 10(4) to 1.2 x 10(5); the coefficients of determination exceeded 0.9938 and the relative standard deviations of the peak heights were less than 3.2%; the detection limits ranged from 0.056 to 0.22 ng/mL. We employed the optimal conditions to analyze these five SSRIs in a plasma sample prepared using solid-phase extraction (SPE) to minimize the influence of the matrix. Although the limits of detection of the SSRIs in human plasma were higher than those in pure water, this present technique is more sensitive than other, more-conventional methods. The recovery of the SPE extraction efficiency was satisfactory (up to 89%). Our findings suggest that, under the optimal conditions, the CSEI-sweeping-MEKC method can be used successfully to determine these five SSRIs in human plasma. PMID:18783779

  10. The crystal structure of MPK38 in complex with OTSSP167, an orally administrative MELK selective inhibitor.

    PubMed

    Cho, Yong-Soon; Kang, Yingjin; Kim, Kuglae; Cha, Young-Je; Cho, Hyun-Soo

    2014-04-25

    Murine protein serine/threonine kinase 38 (MPK38), also known as maternal embryonic leucine zipper kinase (MELK), has been associated with various human cancers and plays an important role in the formation of cancer stem cells. OTSSP167, a MELK selective inhibitor, exhibits a strong in vitro activity, conferring an IC50 of 0.41nM and in vivo effect on various human cancer xenograft models. Here, we report the crystal structure of MPK38 (T167E), an active mutant, in complex with OTSSP167 and describe its detailed protein-inhibitor interactions. Comparison with the previous determined structure of MELK bound to the nanomolar inhibitors shows that OTSSP167 effectively fits into the active site, thus offering an opportunity for structure-based development and optimization of MELK inhibitors. PMID:24657156

  11. Towards the selection of a produced water enrichment for biological gas hydrate inhibitors.

    PubMed

    Wilson, Sandra L; Voordouw, Gerrit; Walker, Virginia K

    2014-09-01

    Economic concerns associated with the recovery of non-conventional hydrocarbon reserves include unexpected ice as well as ice-like gas hydrate formation. Antifreeze proteins (AFPs) inhibit ice growth, and experiments with fish, plant, and insect AFPs have shown promise of effective gas hydrate inhibition in lab-scale experiments. If produced on an industrial scale, AFPs could provide a more environmentally friendly alternative to kinetic inhibitors, but a large-scale production of these AFPs is not currently feasible. We believe that these difficulties could be surmounted by the production of microbial AFPs, but to date, only a few such proteins have been identified and purified, and none of these are associated with hydrocarbon reserves. Here, we have used ice-affinity and freeze-thaw stress to select microbes derived from oil and gas formation water, or produced water, as a source of anaerobic microbial communities. Ice-affinity successfully incorporated anaerobic bacteria under aerobic conditions, and the mixed culture had ice-associating properties. Under these conditions, ice-affinity selection does not result in cultivatable isolates, but similar, cultivable microbes were obtained following freeze-thaw selection under anaerobic conditions. Since these mixed cultures inhibited the growth of ice crystals, they also have the potential to inhibit hydrate growth. Overall, freeze-thaw selection provides a promising first step towards the isolation of microbes capable of the inhibition of ice and gas hydrate growth, for possible application for energy exploration and recovery at high-latitudes and in-deep, cold waters. PMID:24819435

  12. Effect of Narrow Spectrum Versus Selective Kinase Inhibitors on the Intestinal Proinflammatory Immune Response in Ulcerative Colitis

    PubMed Central

    Biancheri, Paolo; Foster, Martyn R.; Fyfe, Matthew C. T.; MacDonald, Thomas T.; Sirohi, Sameer; Solanke, Yemisi; Wood, Eleanor; Rowley, Adele; Webber, Steve

    2016-01-01

    Background: Kinases are key mediators of inflammation, highlighting the potential of kinase inhibitors as treatments for inflammatory disorders. Selective kinase inhibitors, however, have proved disappointing, particularly in the treatment of rheumatoid arthritis and inflammatory bowel disease. Consequently, to improve efficacy, attention has turned to multikinase inhibition. Methods: The activity of a narrow spectrum kinase inhibitor, TOP1210, has been compared with selective kinase inhibitors (BIRB-796, dasatinib and BAY-61-3606) in a range of kinase assays, inflammatory cell assays, and in inflamed biopsies from patients with ulcerative colitis (UC). Effects on recombinant P38α, Src, and Syk kinase activities were assessed using Z-lyte assays (Invitrogen, Paisley, United Kingdom). Anti-inflammatory effects were assessed by measurement of proinflammatory cytokine release from peripheral blood mononuclear cells, primary macrophages, HT29 cells, inflamed colonic UC biopsies, and myofibroblasts isolated from inflamed colonic UC mucosa. Results: TOP1210 potently inhibits P38α, Src, and Syk kinase activities. Similarly, TOP1210 demonstrates potent inhibitory activity against proinflammatory cytokine release in each of the cellular assays and the inflamed colonic UC biopsies and myofibroblasts isolated from inflamed colonic UC mucosa. Generally, the selective kinase inhibitors showed limited and weaker activity in the cellular assays compared with the broad inhibitory profile of TOP1210. However, combination of the selective inhibitors led to improved efficacy and potency in both cellular and UC biopsy assays. Conclusions: Targeted, multikinase inhibition with TOP1210 leads to a broad efficacy profile in both the innate and adaptive immune responses, with significant advantages over existing selective kinase approaches, and potentially offers a much improved therapeutic benefit in inflammatory bowel disease. PMID:27104822

  13. Exploration of Cyanine Compounds as Selective Inhibitors of Protein Arginine Methyltransferases: Synthesis and Biological Evaluation

    PubMed Central

    2016-01-01

    Protein arginine methyltransferase 1 (PRMT1) is involved in many biological activities, such as gene transcription, signal transduction, and RNA processing. Overexpression of PRMT1 is related to cardiovascular diseases, kidney diseases, and cancers; therefore, selective PRMT1 inhibitors serve as chemical probes to investigate the biological function of PRMT1 and drug candidates for disease treatment. Our previous work found trimethine cyanine compounds that effectively inhibit PRMT1 activity. In our present study, we systematically investigated the structure–activity relationship of cyanine structures. A pentamethine compound, E-84 (compound 50), showed inhibition on PRMT1 at the micromolar level and 6- to 25-fold selectivity over CARM1, PRMT5, and PRMT8. The cellular activity suggests that compound 50 permeated the cellular membrane, inhibited cellular PRMT1 activity, and blocked leukemia cell proliferation. Additionally, our molecular docking study suggested compound 50 might act by occupying the cofactor binding site, which provided a roadmap to guide further optimization of this lead compound. PMID:25559100

  14. Substrate-Free High-Throughput Screening Identifies Selective Inhibitors for Uncharacterized Enzymes

    PubMed Central

    Bachovchin, Daniel A.; Brown, Steven J.; Rosen, Hugh; Cravatt, Benjamin F.

    2009-01-01

    Target-based high-throughput screening (HTS) is essential for the discovery of small-molecule modulators of proteins. Typical screening methods for enzymes rely on extensively tailored substrate assays, which are not available for targets of poorly characterized biochemical activity. Here, we report a general, substrate-free platform for HTS that overcomes this problem by monitoring the reaction of broad-spectrum, activity-based probes with enzymes using fluorescence polarization. We show that this platform is applicable to enzymes from multiple mechanistic classes, regardless of their degree of functional annotation, and can be coupled with secondary competitive activity-based proteomic assays to rapidly determine the specificity of screening hits. Using this platform, we identified the bioactive alkaloid emetine as a selective inhibitor of the uncharacterized cancer-associated hydrolase RBBP9. We furthermore show that the detoxification enzyme GSTO1, also implicated in cancer, is inhibited by several electrophilic compounds found in public libraries, some of which display high selectivity for this enzyme. PMID:19329999

  15. Discovery, Synthesis and Biological Evaluation of a Novel Group of Selective Inhibitors of Filoviral Entry

    PubMed Central

    Yermolina, Maria V.; Wang, Jizhen; Caffrey, Michael; Rong, Lijun L.; Wardrop, Duncan J.

    2011-01-01

    Herein, we report the development of an anti-filoviral screening system, based on a pseudotyping strategy, and its application in the discovery of a novel group of small molecules that selectively inhibit the Ebola and Marburg glycoprotein (GP)-mediated infection of human cells. Using Ebola Zaire GP-pseudotyped HIV particles bearing a luciferase reporter gene and 293T cells, a library of 237 small molecules was screened for inhibition of GP-mediated viral entry. From this assay, lead compound 8a was identified as a selective inhibitor of filoviral entry with an IC50 of 30 μM. In order to analyze functional group requirements for efficacy, a structure-activity relationship analysis of this 3,5-disubstituted isoxazole was then conducted with 56 isoxazole and triazole derivatives prepared using “click” chemistry. This study revealed that while the isoxazole ring can be replaced by a triazole system, the 5-(diethylamino)acetamido substituent found in 8a is required for inhibition of viral-cell entry. Variation of the 3-aryl substituent provided a number of more potent anti-viral agents with IC50 values ranging to 2.5 μM. Lead compound 8a and three of its derivatives were also found to block the Marburg glycoprotein (GP)-mediated infection of human cells. PMID:21204524

  16. Effect of a selective thromboxane synthase inhibitor on arterial graft patency and platelet deposition in dogs

    SciTech Connect

    McDaniel, M.D.; Huntsman, W.T.; Miett, T.O.; Cronenwett, J.L.

    1987-08-01

    This study examined the effect of selective thromboxane synthase inhibition and nonselective cyclooxygenase inhibition on vascular graft patency and indium 111-labeled platelet deposition in 35 mongrel dogs undergoing carotid artery replacement with 4 mm X 4 cm polytetrafluoroethylene (PTFE) (one side) and Dacron (opposite side) end-to-end grafts. Aspirin-dipyridamole therapy improved one-week graft patency, from 46% in untreated dogs to 93% in treated dogs. Thromboxane synthase inhibition (U-63557A) improved graft patency in these dogs to 81%. Both drug treatments reduced platelet deposition on Dacron and PTFE grafts by 48% to 68% compared with control dogs. Dacron grafts accumulated significantly more platelets than PTFE grafts but had comparable patency rates. Low-dose aspirin therapy had no significant effect on either graft patency or platelet deposition. All treatment groups showed a 60% to 76% reduction in serum thromboxane B2, but only thromboxane synthase inhibitor treatment increased plasma 6-keto-prostaglandin F1 alpha by 100%. Selective thromboxane synthase inhibition improved small-caliber prosthetic graft patency to the same extent as did conventional cyclooxygenase inhibition in this preliminary study.

  17. Noncovalent Mutant Selective Epidermal Growth Factor Receptor Inhibitors: A Lead Optimization Case Study.

    PubMed

    Heald, Robert; Bowman, Krista K; Bryan, Marian C; Burdick, Daniel; Chan, Bryan; Chan, Emily; Chen, Yuan; Clausen, Saundra; Dominguez-Fernandez, Belen; Eigenbrot, Charles; Elliott, Richard; Hanan, Emily J; Jackson, Philip; Knight, Jamie; La, Hank; Lainchbury, Michael; Malek, Shiva; Mann, Sam; Merchant, Mark; Mortara, Kyle; Purkey, Hans; Schaefer, Gabriele; Schmidt, Stephen; Seward, Eileen; Sideris, Steve; Shao, Lily; Wang, Shumei; Yeap, Kuen; Yen, Ivana; Yu, Christine; Heffron, Timothy P

    2015-11-25

    Because of their increased activity against activating mutants, first-generation epidermal growth factor receptor (EGFR) kinase inhibitors have had remarkable success in treating non-small-cell lung cancer (NSCLC) patients, but acquired resistance, through a secondary mutation of the gatekeeper residue, means that clinical responses only last for 8-14 months. Addressing this unmet medical need requires agents that can target both of the most common double mutants: T790M/L858R (TMLR) and T790M/del(746-750) (TMdel). Herein we describe how a noncovalent double mutant selective lead compound was optimized using a strategy focused on the structure-guided increase in potency without added lipophilicity or reduction of three-dimensional character. Following successive rounds of design and synthesis it was discovered that cis-fluoro substitution on 4-hydroxy- and 4-methoxypiperidinyl groups provided synergistic, substantial, and specific potency gain through direct interaction with the enzyme and/or effects on the proximal ligand oxygen atom. Further development of the fluorohydroxypiperidine series resulted in the identification of a pair of diastereomers that showed 50-fold enzyme and cell based selectivity for T790M mutants over wild-type EGFR (wtEGFR) in vitro and pathway knock-down in an in vivo xenograft model. PMID:26455919

  18. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors

    PubMed Central

    Esteva-Font, Cristina; Cil, Onur; Phuan, Puay-Wah; Su, Tao; Lee, Sujin; Anderson, Marc O.; Verkman, A. S.

    2014-01-01

    Urea transport (UT) proteins of the UT-A class are expressed in epithelial cells in kidney tubules, where they are required for the formation of a concentrated urine by countercurrent multiplication. Here, using a recently developed high-throughput assay to identify UT-A inhibitors, a screen of 50,000 synthetic small molecules identified UT-A inhibitors of aryl-thiazole, γ-sultambenzosulfonamide, aminocarbonitrile butene, and 4-isoxazolamide chemical classes. Structure-activity analysis identified compounds that inhibited UT-A selectively by a noncompetitive mechanism with IC50 down to ∼1 μM. Molecular modeling identified putative inhibitor binding sites on rat UT-A. To test compound efficacy in rats, formulations and administration procedures were established to give therapeutic inhibitor concentrations in blood and urine. We found that intravenous administration of an indole thiazole or a γ-sultambenzosulfonamide at 20 mg/kg increased urine output by 3–5-fold and reduced urine osmolality by ∼2-fold compared to vehicle control rats, even under conditions of maximum antidiuresis produced by 1-deamino-8-d-arginine vasopressin (DDAVP). The diuresis was reversible and showed urea > salt excretion. The results provide proof of concept for the diuretic action of UT-A-selective inhibitors. UT-A inhibitors are first in their class salt-sparing diuretics with potential clinical indications in volume-overload edemas and high-vasopressin-associated hyponatremias.—Esteva-Font, C., Cil, O., Phuan, P.-W., Su, T., Lee, S., Anderson, M. O., Verkman, A. S. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors. PMID:24843071

  19. The novel β2-selective proteasome inhibitor LU-102 synergizes with bortezomib and carfilzomib to overcome proteasome inhibitor resistance of myeloma cells

    PubMed Central

    Kraus, Marianne; Bader, Juergen; Geurink, Paul P.; Weyburne, Emily S.; Mirabella, Anne C.; Silzle, Tobias; Shabaneh, Tamer B.; van der Linden, Wouter A.; de Bruin, Gerjan; Haile, Sarah R.; van Rooden, Eva; Appenzeller, Christina; Li, Nan; Kisselev, Alexei F.; Overkleeft, Herman; Driessen, Christoph

    2015-01-01

    Proteasome inhibitor resistance is a challenge for myeloma therapy. Bortezomib targets the β5 and β1 activity, but not the β2 activity of the proteasome. Bortezomib-resistant myeloma cells down-regulate the activation status of the unfolded protein response, and up-regulate β2 proteasome activity. To improve proteasome inhibition in bortezomib-resistant myeloma and to achieve more efficient UPR activation, we have developed LU-102, a selective inhibitor of the β2 proteasome activity. LU-102 inhibited the β2 activity in intact myeloma cells at low micromolar concentrations without relevant co-inhibition of β1 and β5 proteasome subunits. In proteasome inhibitor-resistant myeloma cells, significantly more potent proteasome inhibition was achieved by bortezomib or carfilzomib in combination with LU-102, compared to bortezomib/carfilzomib alone, resulting in highly synergistic cytotoxic activity of the drug combination via endoplasmatic reticulum stress-induced apoptosis. Combining bortezomib/carfilzomib with LU-102 significantly prolonged proteasome inhibition and increased activation of the unfolded protein response and IRE1-a activity. IRE1-α has recently been shown to control myeloma cell differentiation and bortezomib sensitivity (Leung-Hagesteijn, Cancer Cell 24:3, 289-304). Thus, β2-selective proteasome inhibition by LU-102 in combination with bortezomib or carfilzomib results in synergistic proteasome inhibition, activation of the unfolded protein response, and cytotoxicity, and overcomes bortezomib/carfilzomib resistance in myeloma cells in vitro PMID:26069288

  20. The novel β2-selective proteasome inhibitor LU-102 synergizes with bortezomib and carfilzomib to overcome proteasome inhibitor resistance of myeloma cells.

    PubMed

    Kraus, Marianne; Bader, Juergen; Geurink, Paul P; Weyburne, Emily S; Mirabella, Anne C; Silzle, Tobias; Shabaneh, Tamer B; van der Linden, Wouter A; de Bruin, Gerjan; Haile, Sarah R; van Rooden, Eva; Appenzeller, Christina; Li, Nan; Kisselev, Alexei F; Overkleeft, Herman; Driessen, Christoph

    2015-10-01

    Proteasome inhibitor resistance is a challenge for myeloma therapy. Bortezomib targets the β5 and β1 activity, but not the β2 activity of the prot