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Lloyd MD, Yevglevskis M, Nathubhai A, James TD, Threadgill MD, Woodman TJ. Racemases and epimerases operating through a 1,1-proton transfer mechanism: reactivity, mechanism and inhibition. Chem Soc Rev 2021; 50:5952-5984. [PMID: 34027955 PMCID: PMC8142540 DOI: 10.1039/d0cs00540a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 12/12/2022]
Abstract
Racemases and epimerases catalyse changes in the stereochemical configurations of chiral centres and are of interest as model enzymes and as biotechnological tools. They also occupy pivotal positions within metabolic pathways and, hence, many of them are important drug targets. This review summarises the catalytic mechanisms of PLP-dependent, enolase family and cofactor-independent racemases and epimerases operating by a deprotonation/reprotonation (1,1-proton transfer) mechanism and methods for measuring their catalytic activity. Strategies for inhibiting these enzymes are reviewed, as are specific examples of inhibitors. Rational design of inhibitors based on substrates has been extensively explored but there is considerable scope for development of transition-state mimics and covalent inhibitors and for the identification of inhibitors by high-throughput, fragment and virtual screening approaches. The increasing availability of enzyme structures obtained using X-ray crystallography will facilitate development of inhibitors by rational design and fragment screening, whilst protein models will facilitate development of transition-state mimics.
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Affiliation(s)
- Matthew D Lloyd
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - Maksims Yevglevskis
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and CatSci Ltd., CBTC2, Capital Business Park, Wentloog, Cardiff CF3 2PX, UK
| | - Amit Nathubhai
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and University of Sunderland, School of Pharmacy & Pharmaceutical Sciences, Sciences Complex, Sunderland SR1 3SD, UK
| | - Tony D James
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK and School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, People's Republic of China
| | - Michael D Threadgill
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth SY23 3BY, UK
| | - Timothy J Woodman
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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2
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Bearne SL. Through the Looking Glass: Chiral Recognition of Substrates and Products at the Active Sites of Racemases and Epimerases. Chemistry 2020; 26:10367-10390. [DOI: 10.1002/chem.201905826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/09/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Stephen L. Bearne
- Department of Biochemistry & Molecular BiologyDepartment of ChemistryDalhousie University Halifax, Nova Scotia B3H 4R2 Canada
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Kong G, Lee H, Tran Q, Kim C, Park J, Kwon SH, Kim SH, Park J. Current Knowledge on the Function of α-Methyl Acyl-CoA Racemase in Human Diseases. Front Mol Biosci 2020; 7:153. [PMID: 32760737 PMCID: PMC7372137 DOI: 10.3389/fmolb.2020.00153] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/18/2020] [Indexed: 01/22/2023] Open
Abstract
Branched chain fatty acids perform very important functions in human diet and drug metabolism. they cannot be metabolized in mitochondria and are instead processed and degraded in peroxisomes due to the presence of methyl groups on the carbon chains. Oxidative degradation pathways for lipids include α- and β-oxidation and several pathways. In all metabolic pathways, α-methyl acyl-CoA racemase (AMACR) plays an essential role by regulating the metabolism of lipids and drugs. AMACR regulates β-oxidation of branched chain lipids in peroxisomes and mitochondria and promotes chiral reversal of 2-methyl acids. AMACR defects cause sensory-motor neuronal and liver abnormalities in humans. These phenotypes are inherited and are caused by mutations in AMACR. In addition, AMACR has been found to be overexpressed in prostate cancer. In addition, the protein levels of AMACR have increased significantly in many types of cancer. Therefore, AMACR may be an important marker in tumors. In this review, a comprehensive overview of AMACR studies in human disease will be described.
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Affiliation(s)
- Gyeyeong Kong
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Hyunji Lee
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Quangdon Tran
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Chaeyeong Kim
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Jisoo Park
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Life Science, Hyehwa Liberal Arts College, LINC Plus Project Group, Daejeon University, Daejeon, South Korea
| | - So Hee Kwon
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | - Seon-Hwan Kim
- Department of Neurosurgery, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Jongsun Park
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, South Korea
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Van Veldhoven PP, de Schryver E, Young SG, Zwijsen A, Fransen M, Espeel M, Baes M, Van Ael E. Slc25a17 Gene Trapped Mice: PMP34 Plays a Role in the Peroxisomal Degradation of Phytanic and Pristanic Acid. Front Cell Dev Biol 2020; 8:144. [PMID: 32266253 PMCID: PMC7106852 DOI: 10.3389/fcell.2020.00144] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/20/2020] [Indexed: 12/04/2022] Open
Abstract
Mice lacking PMP34, a peroxisomal membrane transporter encoded by Slc25a17, did not manifest any obvious phenotype on a Swiss Webster genetic background, even with various treatments designed to unmask impaired peroxisomal functioning. Peroxisomal α- and β-oxidation rates in PMP34 deficient fibroblasts or liver slices were not or only modestly affected and in bile, no abnormal bile acid intermediates were detected. Peroxisomal content of cofactors like CoA, ATP, NAD+, thiamine-pyrophosphate and pyridoxal-phosphate, based on direct or indirect data, appeared normal as were tissue plasmalogen and very long chain fatty acid levels. However, upon dietary phytol administration, the knockout mice displayed hepatomegaly, liver inflammation, and an induction of peroxisomal enzymes. This phenotype was partially mediated by PPARα. Hepatic triacylglycerols and cholesterylesters were elevated and both phytanic acid and pristanic acid accumulated in the liver lipids, in females to higher extent than in males. In addition, pristanic acid degradation products were detected, as wells as the CoA-esters of all these branched fatty acids. Hence, PMP34 is important for the degradation of phytanic/pristanic acid and/or export of their metabolites. Whether this is caused by a shortage of peroxisomal CoA affecting the intraperoxisomal formation of pristanoyl-CoA (and perhaps of phytanoyl-CoA), or the SCPx-catalyzed thiolytic cleavage during pristanic acid β-oxidation, could not be proven in this model, but the phytol-derived acyl-CoA profile is compatible with the latter possibility. On the other hand, the normal functioning of other peroxisomal pathways, and especially bile acid formation, seems to exclude severe transport problems or a shortage of CoA, and other cofactors like FAD, NAD(P)+, TPP. Based on our findings, PMP34 deficiency in humans is unlikely to be a life threatening condition but could cause elevated phytanic/pristanic acid levels in older adults.
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Affiliation(s)
| | - Evelyn de Schryver
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Stephen G. Young
- Departments of Medicine and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - An Zwijsen
- Laboratory of Developmental Signaling, Department Human Genetics, VIB-KU Leuven, Leuven, Belgium
| | - Marc Fransen
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Marc Espeel
- Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University, Ghent, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Faculty of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Elke Van Ael
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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Petrova YD, Wadda K, Nathubhai A, Yevglevskis M, Mitchell PJ, James TD, Threadgill MD, Woodman TJ, Lloyd MD. Identification of novel small-molecule inhibitors of α-methylacyl-CoA racemase (AMACR; P504S) and structure-activity relationships. Bioorg Chem 2019; 92:103264. [PMID: 31536955 DOI: 10.1016/j.bioorg.2019.103264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 12/24/2022]
Abstract
α-Methylacyl-CoA racemase (AMACR; P504S; EC 5.1.99.4) catalyses epimerization of 2-methylacyl-CoAs and is important for the degradation of branched-chain fatty acids and the pharmacological activation of ibuprofen and related drugs. It is also a novel drug target for prostate and other cancers. However, development of AMACR as a drug target has been hampered by the difficulties in assaying enzyme activity. Consequently, reported inhibitors have been rationally designed acyl-CoA esters, which are delivered as their carboxylate prodrugs. The novel colorimetric assay for AMACR based on the elimination of 2,4-dinitrophenolate was developed for high-throughput screening and 20,387 'drug-like compounds' were screened, with a throughput of 768 compounds assayed per day. Pyrazoloquinolines and pyrazolopyrimidines were identified as novel scaffolds and investigated as AMACR inhibitors. The most potent inhibitors have IC50 values of ~2 µM. The pyrazoloquinoline inhibitor 10a displayed uncompetitive inhibition, whilst 10j displayed mixed competitive inhibition. The pyrazolopyrimidine inhibitor 11k displayed uncompetitive inhibition. This is the first report of the identification of specific drug-like small-molecule AMACR inhibitors by high-throughput screening. Pyrazoloquinolines and pyrazolopyrimidines may also be useful as inhibitors of other CoA-utilizing enzymes.
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Affiliation(s)
- Yoana D Petrova
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Katty Wadda
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Amit Nathubhai
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK; School of Pharmacy and Pharmaceutical Sciences, Sciences Complex, City Campus, Dale Building, Room 121, Sunderland SR1 3SD, UK(1)
| | - Maksims Yevglevskis
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Paul J Mitchell
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Tony D James
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Michael D Threadgill
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Timothy J Woodman
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Matthew D Lloyd
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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Yevglevskis M, Nathubhai A, Wadda K, Lee GL, Al-Rawi S, Jiao T, Mitchell PJ, James TD, Threadgill MD, Woodman TJ, Lloyd MD. Novel 2-arylthiopropanoyl-CoA inhibitors of α-methylacyl-CoA racemase 1A (AMACR; P504S) as potential anti-prostate cancer agents. Bioorg Chem 2019; 92:103263. [PMID: 31536953 DOI: 10.1016/j.bioorg.2019.103263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 10/26/2022]
Abstract
α-Methylacyl-CoA racemase (AMACR; P504S) catalyses an essential step in the degradation of branched-chain fatty acids and the activation of ibuprofen and related drugs. AMACR has gained much attention as a drug target and biomarker, since it is found at elevated levels in prostate cancer and several other cancers. Herein, we report the synthesis of 2-(phenylthio)propanoyl-CoA derivatives which provided potent AMACR inhibitory activity (IC50 = 22-100 nM), as measured by the AMACR colorimetric activity assay. Inhibitor potency positively correlates with calculated logP, although 2-(3-benzyloxyphenylthio)propanoyl-CoA and 2-(4-(2-methylpropoxy)phenylthio)propanoyl-CoA were more potent than predicted by this parameter. Subsequently, carboxylic acid precursors were evaluated against androgen-dependent LnCaP prostate cancer cells and androgen-independent Du145 and PC3 prostate cancer cells using the MTS assay. All tested precursor acids showed inhibitory activity against LnCaP, Du145 and PC3 cells at 500 µM, but lacked activity at 100 µM. This is the first extensive structure-activity relationship study on the influence of side-chain interactions on the potency of novel rationally designed AMACR inhibitors.
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Affiliation(s)
- Maksims Yevglevskis
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Amit Nathubhai
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK; University of Sunderland, School of Pharmacy and Pharmaceutical Sciences, Sciences Complex, Sunderland SR1 3SD, UK(1)
| | - Katty Wadda
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Guat L Lee
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Suzanne Al-Rawi
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Tingying Jiao
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK; School of Pharmaceutical Sciences, Shandong University, Jinan, People's Republic of China
| | - Paul J Mitchell
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Tony D James
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Michael D Threadgill
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Timothy J Woodman
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Matthew D Lloyd
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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Mezzar S, De Schryver E, Asselberghs S, Meyhi E, Morvay PL, Baes M, Van Veldhoven PP. Phytol-induced pathology in 2-hydroxyacyl-CoA lyase (HACL1) deficient mice. Evidence for a second non-HACL1-related lyase. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28629946 DOI: 10.1016/j.bbalip.2017.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
2-Hydroxyacyl-CoA lyase (HACL1) is a key enzyme of the peroxisomal α-oxidation of phytanic acid. To better understand its role in health and disease, a mouse model lacking HACL1 was investigated. Under normal conditions, these mice did not display a particular phenotype. However, upon dietary administration of phytol, phytanic acid accumulated in tissues, mainly in liver and serum of KO mice. As a consequence of phytanic acid (or a metabolite) toxicity, KO mice displayed a significant weight loss, absence of abdominal white adipose tissue, enlarged and mottled liver and reduced hepatic glycogen and triglycerides. In addition, hepatic PPARα was activated. The central nervous system of the phytol-treated mice was apparently not affected. In addition, 2OH-FA did not accumulate in the central nervous system of HACL1 deficient mice, likely due to the presence in the endoplasmic reticulum of an alternate HACL1-unrelated lyase. The latter may serve as a backup system in certain tissues and account for the formation of pristanic acid in the phytol-fed KO mice. As the degradation of pristanic acid is also impaired, both phytanoyl- and pristanoyl-CoA levels are increased in liver, and the ω-oxidized metabolites are excreted in urine. In conclusion, HACL1 deficiency is not associated with a severe phenotype, but in combination with phytanic acid intake, the normal situation in man, it might present with phytanic acid elevation and resemble a Refsum like disorder.
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Affiliation(s)
- Serena Mezzar
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Evelyn De Schryver
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Stanny Asselberghs
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Els Meyhi
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Petruta L Morvay
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Myriam Baes
- Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium
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Esfahani M, Ataei N, Panjehpour M. Biomarkers for evaluation of prostate cancer prognosis. Asian Pac J Cancer Prev 2016; 16:2601-11. [PMID: 25854335 DOI: 10.7314/apjcp.2015.16.7.2601] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Prostate cancer, with a lifetime prevalence of one in six men, is the second cause of malignancy-related death and the most prevalent cancer in men in many countries. Nowadays, prostate cancer diagnosis is often based on the use of biomarkers, especially prostate-specific antigen (PSA) which can result in enhanced detection at earlier stage and decreasing in the number of metastatic patients. However, because of the low specificity of PSA, unnecessary biopsies and mistaken diagnoses frequently occur. Prostate cancer has various features so prognosis following diagnosis is greatly variable. There is a requirement for new prognostic biomarkers, particularly to differentiate between inactive and aggressive forms of disease, to improve clinical management of prostate cancer. Research continues into finding additional markers that may allow this goal to be attained. We here selected a group of candidate biomarkers including PSA, PSA velocity, percentage free PSA, TGFβ1, AMACR, chromogranin A, IL-6, IGFBPs, PSCA, biomarkers related to cell cycle regulation, apoptosis, PTEN, androgen receptor, cellular adhesion and angiogenesis, and also prognostic biomarkers with Genomic tests for discussion. This provides an outline of biomarkers that are presently of prognostic interest in prostate cancer investigation.
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Affiliation(s)
- Maryam Esfahani
- Department of Clinical Biochemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran E-mail :
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Yevglevskis M, Lee GL, Sun J, Zhou S, Sun X, Kociok-Köhn G, James TD, Woodman TJ, Lloyd MD. A study on the AMACR catalysed elimination reaction and its application to inhibitor testing. Org Biomol Chem 2016; 14:612-622. [PMID: 26537174 PMCID: PMC4718014 DOI: 10.1039/c5ob01541c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 10/27/2015] [Indexed: 12/15/2022]
Abstract
α-Methylacyl-CoA racemase (AMACR; P504S) catalyses a key step in the degradation of branched-chain fatty acids and is important for the pharmacological activation of Ibuprofen and related drugs. Levels of AMACR are increased in prostate and other cancers, and it is a drug target. Development of AMACR as a drug target is hampered by lack of a convenient assay. AMACR irreversibly catalyses the elimination of HF from 3-fluoro-2-methylacyl-CoA substrates, and this reaction was investigated for use as an assay. Several known inhibitors and alternative substrates reduced conversion of 3-fluoro-2-methyldecanoyl-CoA by AMACR, as determined by (1)H NMR. The greatest reduction of activity was observed with known potent inhibitors. A series of novel acyl-CoA esters with aromatic side chains were synthesised for testing as chromophoric substrates. These acyl-CoA esters were converted to unsaturated products by AMACR, but their use was limited by non-enzymatic elimination. Fluoride sensors were also investigated as a method of quantifying released fluoride and thus AMACR activity. These sensors generally suffered from high background signal and lacked reproducibility under the assay conditions. In summary, the elimination reaction can be used to characterise inhibitors, but it was not possible to develop a convenient colorimetric or fluorescent assay using 3-fluoro-2-methylacyl-CoA substrates.
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Affiliation(s)
- Maksims Yevglevskis
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
| | - Guat L. Lee
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
| | - Jenny Sun
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
- Department of Pharmacy , Shandong University , People's Republic of China
| | - Shiyi Zhou
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
- Department of Pharmacy , Shandong University , People's Republic of China
| | - Xiaolong Sun
- Department of Chemistry , University of Bath , Claverton Down , Bath BA2 7AY , UK
| | - Gabriele Kociok-Köhn
- Department of Chemistry , University of Bath , Claverton Down , Bath BA2 7AY , UK
| | - Tony D. James
- Department of Chemistry , University of Bath , Claverton Down , Bath BA2 7AY , UK
| | - Timothy J. Woodman
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
| | - Matthew D. Lloyd
- Medicinal Chemistry , Department of Pharmacy & Pharmacology , University of Bath , Claverton Down , Bath BA2 7AY , UK . ; Fax: +44 (0)1225 386114
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10
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Lloyd MD, Yevglevskis M, Lee GL, Wood PJ, Threadgill MD, Woodman TJ. α-Methylacyl-CoA racemase (AMACR): Metabolic enzyme, drug metabolizer and cancer marker P504S. Prog Lipid Res 2013; 52:220-30. [DOI: 10.1016/j.plipres.2013.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
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Wilson BA, Wang H, Nacev BA, Mease RC, Liu JO, Pomper MG, Isaacs WB. High-throughput screen identifies novel inhibitors of cancer biomarker α-methylacyl coenzyme A racemase (AMACR/P504S). Mol Cancer Ther 2011; 10:825-38. [PMID: 21441411 PMCID: PMC3423201 DOI: 10.1158/1535-7163.mct-10-0902] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
α-methylacyl coenzyme A racemase (AMACR) is a metabolic enzyme whose overexpression has been shown to be a diagnostic indicator of prostatic adenocarcinoma and other solid tumors. Here, we confirm that attenuation of AMACR expression diminishes the growth of prostate cancer cell lines by using stably expressed short-hairpin RNA constructs. This observation strongly suggests that the AMACR enzyme may be a target for therapeutic inhibition in prostate cancer. To this end, we report here a novel assay capable of screening libraries of diverse small molecules for inhibitors of AMACR activity. This assay facilitated the screening of approximately 5,000 unique compounds and the discovery of 7 distinct chemical entities capable of inhibiting AMACR at low micromolar concentrations. The most potent inhibitor discovered is the seleno-organic compound ebselen oxide [inhibitory concentration (IC(50)): 0.80 μmol/L]. The parent compound, ebselen (IC(50): 2.79 μmol/L), is a covalent inactivator of AMACR (K(I)((inact)): 24 μmol/L). Two of the AMACR inhibitors are selectively toxic to prostate cancer cell lines (LAPC4/LNCaP/PC3) that express AMACR compared to a normal prostate fibroblast cell line (WPMY1) that does not express the protein. This report shows the first high-throughput screen for the discovery of novel AMACR inhibitors, characterizes the first nonsubstrate-based inhibitors, and validates that AMACR is a viable chemotherapeutic target in vitro.
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Affiliation(s)
- Brice A.P. Wilson
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Haofan Wang
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Benjamin A. Nacev
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ronnie C. Mease
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Jun O. Liu
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Martin G. Pomper
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - William B. Isaacs
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD
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12
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Santillo A, Monteforte R, De Lange P, Lanni A, Farina P, Baccari GC. Dimorphic expression of uncoupling protein-3 in golden hamster harderian gland: Effects of castration and testosterone administration. J Cell Physiol 2008; 215:481-7. [DOI: 10.1002/jcp.21333] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Sakai Y, Takahashi H, Wakasa Y, Kotani T, Yurimoto H, Miyachi N, Van Veldhoven PP, Kato N. Role of alpha-methylacyl coenzyme A racemase in the degradation of methyl-branched alkanes by Mycobacterium sp. strain P101. J Bacteriol 2004; 186:7214-20. [PMID: 15489432 PMCID: PMC523219 DOI: 10.1128/jb.186.21.7214-7220.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new isolate, Mycobacterium sp. strain P101, is capable of growth on methyl-branched alkanes (pristane, phytane, and squalane). Among ca. 10,000 Tn5-derived mutants, we characterized 2 mutants defective in growth on pristane or n-hexadecane. A single copy of Tn5 was found to be inserted into the coding region of mcr (alpha-methylacyl coenzyme A [alpha-methylacyl-CoA] racemase gene) in mutant P1 and into the coding region of mls (malate synthase gene) in mutant H1. Mutant P1 could not grow on methyl-branched alkanes. The recombinant Mcr produced in Escherichia coli was confirmed to catalyze racemization of (R)-2-methylpentadecanoyl-CoA, with a specific activity of 0.21 micromol . min(-1) . mg of protein(-1). Real-time quantitative reverse transcriptase PCR analyses indicated that mcr gene expression was enhanced by the methyl-branched alkanes pristane and squalane. Mutant P1 used (S)-2-methylbutyric acid for growth but did not use the racemic compound, and growth on n-hexadecane was not inhibited by pristane. These results suggested that the oxidation of the methyl-branched alkanoic acid is inhibited by the (R) isomer, although the (R) isomer was not toxic during growth on n-hexadecane. Based on these results, Mcr is suggested to play a critical role in beta-oxidation of methyl-branched alkanes in Mycobacterium. On the other hand, mutant H1 could not grow on n-hexadecane, but it partially retained the ability to grow on pristane. The reduced growth of mutant H1 on pristane suggests that propionyl-CoA is available for cell propagation through the 2-methyl citric acid cycle, since propionyl-CoA is produced through beta-oxidation of pristane.
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Affiliation(s)
- Yasuyoshi Sakai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
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14
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Kumar-Sinha C, Shah RB, Laxman B, Tomlins SA, Harwood J, Schmitz W, Conzelmann E, Sanda MG, Wei JT, Rubin MA, Chinnaiyan AM. Elevated alpha-methylacyl-CoA racemase enzymatic activity in prostate cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 164:787-93. [PMID: 14982833 PMCID: PMC1613269 DOI: 10.1016/s0002-9440(10)63167-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Alpha-methylacyl-CoA racemase (AMACR) is a peroxisomal and mitochondrial enzyme involved in the beta-oxidation of branched fatty acids, shown to be elevated in prostate cancer by several recent studies. Sequence variants of AMACR have been linked to prostate cancer risk. Although mRNA transcript, protein, and sequence variants of AMACR have been studied in the context of prostate cancer, AMACR enzymatic activity has not been addressed. Here we present evidence that AMACR activity is consistently elevated in prostate cancer tissue specimens. This activity can be immunodepleted from prostate cancer tissue extracts. Furthermore, mock needle biopsy cores containing foci of prostate cancer exhibited increased AMACR enzymatic activity, correlating with both protein levels and histopathology. Taken together, our studies suggest that AMACR activity is increased in prostate cancer relative to benign epithelia and suggests that monitoring AMACR activity levels in prostate needle biopsies may have clinical applications.
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Affiliation(s)
- Chandan Kumar-Sinha
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0602, USA
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15
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Evans AJ. Alpha-methylacyl CoA racemase (P504S): overview and potential uses in diagnostic pathology as applied to prostate needle biopsies. J Clin Pathol 2004; 56:892-7. [PMID: 14645345 PMCID: PMC1770134 DOI: 10.1136/jcp.56.12.892] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The diagnosis of prostatic adenocarcinoma remains dependent on the recognition of basic haematoxylin and eosin criteria. The discovery of alpha-methylacyl CoA racemase/P504S (AMACR/P504S) overexpression in prostate cancer represents a triumph of high throughput microarray technology, and is a powerful demonstration of how this methodology can be used to facilitate the rapid development of diagnostically relevant antibodies. Immunohistochemistry with anti-AMACR/P504S is useful for detecting prostate cancer in the full range of prostate specimens encountered in surgical pathology, be they needle biopsies, transurethral resection of prostate chips, or prostatectomies. In particular, studies to date with AMACR/P504S clearly demonstrate the ability of this marker to support a diagnosis of malignancy in prostate needle biopsies. This is particularly true when it is combined with negative staining for a basal cell marker, such as 34betaE12 or p63. Although it has limitations with respect to sensitivity and specificity, AMACR/P504S will no doubt become a standard adjunctive stain used by pathologists seeking to reach a definitive diagnosis in prostate biopsies considered to be atypical, but not diagnostic of malignancy on haematoxylin and eosin sections alone.
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Affiliation(s)
- A J Evans
- Department of Laboratory Medicine and Pathology, University of Toronto, University Health Network, Ontario, Canada.
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16
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Van Veldhoven PP, Meyhi E, Squires RH, Fransen M, Fournier B, Brys V, Bennett MJ, Mannaerts GP. Fibroblast studies documenting a case of peroxisomal 2-methylacyl-CoA racemase deficiency: possible link between racemase deficiency and malabsorption and vitamin K deficiency. Eur J Clin Invest 2001; 31:714-22. [PMID: 11473573 DOI: 10.1046/j.1365-2362.2001.00877.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND 2-Methylacyl-CoA racemase interconverts the 2-methyl group of pristanoyl-CoA or the 25-methyl group of hydroxylated cholestanoyl-CoAs, allowing further peroxisomal desaturation of these compounds in man by the branched chain acyl-CoA oxidase, which recognise only the S-isomers. Hence, oxidation studies in fibroblasts, currently based on the use of racemic substrates such as [1-14C] pristanic acid, do not allow us to distinguish between a deficient racemase or an impaired oxidase. DESIGN To evaluate the racemase activity directly, the 2R-isomer of[1-14C] pristanic acid, as well as the 2R-isomer of 2-methyl-[1-14C] hexadecanoic, a synthetic pristanic acid substitute, were prepared and their degradation by cultured human skin fibroblasts was compared to that of the racemic substrates. RESULTS In fibroblasts in a young girl, presenting with elevated urinary levels of trihydroxycholestanoic acid metabolites but normal plasma levels of very long chain fatty acids, a partial deficient degradation of racemic [1-14C] pristanic acid was observed. Incorporation of 2R-[1-14C] pristanic acid in glycerolipids of the patient's fibroblasts proceeded normally, but breakdown was impaired. Similar findings were seen with the 2R-isomer of 2-methyl-[1-14C] hexadecanoic. These data, combined with the fact that the branched chain acyl-CoA oxidase, catalyzing the first oxidation step of pristanic acid and bile acid intermediates in man, appeared normal, suggested a peroxisomal beta-oxidation defect in the patient at the level of 2-methylacyl-CoA racemase. CONCLUSION Carboxy-labelled 2R-methyl branched chain fatty acids might be useful tools to document cases of racemase deficiencies. Because a brother of the patient died with a diagnosis of vitamin K deficiency, an impaired racemase might be responsible for other cases of unexplicable malabsorption.
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Affiliation(s)
- P P Van Veldhoven
- Katholieke Universiteit Leuven, Afdeling Farmacologie, Leuven, Belgium.
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17
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Amery L, Fransen M, De Nys K, Mannaerts GP, Van Veldhoven PP. Mitochondrial and peroxisomal targeting of 2-methylacyl-CoA racemase in humans. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)31968-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Ferdinandusse S, Denis S, IJlst L, Dacremont G, Waterham HR, Wanders RJ. Subcellular localization and physiological role of α-methylacyl-CoA racemase. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)31983-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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19
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Van Veldhoven PP, Mannaerts GP. Role and organization of peroxisomal beta-oxidation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 466:261-72. [PMID: 10709653 DOI: 10.1007/0-306-46818-2_31] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
In mammals, peroxisomes are involved in breakdown of very long chain fatty acids, prostanoids, pristanic acid, dicarboxylic fatty acids, certain xenobiotics and bile acid intermediates. Substrate spectrum and specificity studies of the four different beta-oxidation steps in rat and/or in man demonstrate that these substrates are degraded by separate beta-oxidation systems composed of different enzymes. In both species, the enzymes acting on straight chain fatty acids are palmitoyl-CoA oxidase, an L-specific multifunctional protein (MFP-1) and a dimeric thiolase. In liver, bile acid intermediates undergo one cycle of beta-oxidation catalyzed by trihydroxycoprostanoyl-CoA oxidase (in rat), or branched chain acyl-CoA oxidase (in man), a D-specific multifunctional protein (MFP-2) and SCPX-thiolase. Finally, pristanic acid is degraded in rat tissues by pristanoyl-CoA oxidase, the D-specific multifunctional protein-2 and SCPX-thiolase. Although in man a pristanoyl-CoA oxidase gene is present, so far its product has not been found. Hence, pristanoyl-CoA is believed to be desaturated in human tissues by the branched chain acyl-CoA oxidase. Due to the stereospecificity of the oxidases acting on 2-methyl-branched substrates, an additional enzyme, 2-methylacyl-CoA racemase, is required for the degradation of pristanic acid and the formation of bile acids.
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20
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Ferdinandusse S, Denis S, Clayton PT, Graham A, Rees JE, Allen JT, McLean BN, Brown AY, Vreken P, Waterham HR, Wanders RJ. Mutations in the gene encoding peroxisomal alpha-methylacyl-CoA racemase cause adult-onset sensory motor neuropathy. Nat Genet 2000; 24:188-91. [PMID: 10655068 DOI: 10.1038/72861] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sensory motor neuropathy is associated with various inherited disorders including Charcot-Marie-Tooth disease, X-linked adrenoleukodystrophy/adrenomyeloneuropathy and Refsum disease. In the latter two, the neuropathy is thought to result from the accumulation of specific fatty acids. We describe here three patients with elevated plasma concentrations of pristanic acid (a branched-chain fatty acid) and C27-bile-acid intermediates. Two of the patients suffered from adult-onset sensory motor neuropathy. One patient also had pigmentary retinopathy, suggesting Refsum disease, whereas the other patient had upper motor neuron signs in the legs, suggesting adrenomyeloneuropathy. The third patient was a child without neuropathy. In all three patients we discovered a deficiency of alpha-methylacyl-CoA racemase (AMACR). This enzyme is responsible for the conversion of pristanoyl-CoA and C27-bile acyl-CoAs to their (S)-stereoisomers, which are the only stereoisomers that can be degraded via peroxisomal beta-oxidation. Sequence analysis of AMACR cDNA from the patients identified two different mutations that are likely to cause disease, based on analysis in Escherichia coli. Our findings have implications for the diagnosis of adult-onset neuropathies of unknown aetiology.
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Affiliation(s)
- S Ferdinandusse
- Department of Clinical Chemistry, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, The Netherlands
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21
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22
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Esquenet M, Swinnen JV, Van Veldhoven PP, Denef C, Heyns W, Verhoeven G. Retinoids stimulate lipid synthesis and accumulation in LNCaP prostatic adenocarcinoma cells. Mol Cell Endocrinol 1997; 136:37-46. [PMID: 9510066 DOI: 10.1016/s0303-7207(97)00210-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In a previous report we demonstrated that androgens markedly stimulate accumulation of lipid droplets in LNCaP cells. The effects were already evident at low concentrations of androgens optimal for proliferation but became much more pronounced at high concentrations optimal for differentiation. In the present report we explored whether other agonists acting by nuclear receptors and modulating LNCaP growth and differentiation also affect lipid accumulation. The agonists investigated were 1alpha,25-dihydroxycholecalciferol (VD3), all-trans-retinoic acid (atRA), and triiodothyronine (T3). Lipid accumulation was evaluated by Oil Red O staining followed by image analysis of Oil Red O-stained cells or by extraction and measurement of absorbency. Only marginal effects were noted for VD3 and T3. The atRA, on the contrary, increased lipid staining 5-12-fold. This effect required high concentrations of retinoids (10[-6] M) and was accompanied by growth stimulation. Lipid accumulation was less pronounced than that observed with maximally effective concentrations of androgens (10[-3] M R1881). Thin layer chromatography (TLC) and enzymatic determination of the various lipid fractions demonstrated that retinoids increase triacylglycerides and an unidentified lipid fraction with a slightly higher mobility. In contrast with androgens, however, they did not stimulate the accumulation of cholesterol esters. Incorporation studies with [2-14C]acetate revealed that the increased accumulation of the mentioned lipids is related both to increased synthesis and to decreased secretion. Retinoid-induced lipid accumulation is accompanied by increased steady-state levels of the mRNA encoding fatty acid synthase (FAS), a key enzyme involved in lipid synthesis, while the expression of HMG-CoA-reductase, an enzyme controlling cholesterol synthesis is only marginally affected. It is concluded that retinoids share the ability of androgens to increase lipid accumulation in LNCaP cells. The nature of the lipids affected by both agonists, however, differs at least in part suggesting that the underlying mechanisms may also be different. For the studied compounds (androgens, VD3, atRA, and T3) no simple and consistent relationship could be observed between their ability to decrease proliferation and increase differentiation on the one hand and their ability to promote lipid accumulation on the other hand.
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Affiliation(s)
- M Esquenet
- Laboratory for Experimental Medicine and Endocrinology, Onderwijs en Navorsing, Gasthuisberg, Leuven, Belgium
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23
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Van Veldhoven PP, Swinnen JV, Esquenet M, Verhoeven G. Lipase-based quantitation of triacylglycerols in cellular lipid extracts: requirement for presence of detergent and prior separation by thin-layer chromatography. Lipids 1997; 32:1297-300. [PMID: 9438240 DOI: 10.1007/s11745-006-0166-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A protocol, based on the use of Pseudomonas lipase, is presented to measure quantitatively the amount of triacylglycerols in extracts from cultured cells of tissues. Since the lipase also acts on di- and monoacylglycerols, separation of the extracts by thin-layer chromatography is recommended. In order to allow the lipase-catalyzed hydrolysis to proceed efficiently, lipid extracts or eluates from silica scrapings were mixed with the detergent Thesit [dodecylpoly(ethylene glycol ether)], prior to drying. After dissolution of the dried residues in water, the amount of triacylglycerols was quantified using Pseudomonas sp. lipase, glycerol kinase, glycerol-phosphate oxidase, and peroxidase. The activity of the latter enzyme was followed either colorimetrically in the presence of 4-aminoantipyrine and 2,4,6-tribromo-3-hydroxybenzoic acid or fluorimetrically in the presence of homovanillic acid.
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Antonenkov VD, Van Veldhoven PP, Waelkens E, Mannaerts GP. Substrate specificities of 3-oxoacyl-CoA thiolase A and sterol carrier protein 2/3-oxoacyl-CoA thiolase purified from normal rat liver peroxisomes. Sterol carrier protein 2/3-oxoacyl-CoA thiolase is involved in the metabolism of 2-methyl-branched fatty acids and bile acid intermediates. J Biol Chem 1997; 272:26023-31. [PMID: 9325339 DOI: 10.1074/jbc.272.41.26023] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The two main thiolase activities present in isolated peroxisomes from normal rat liver were purified to near homogeneity. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the first enzyme preparation displayed a single band of 41 kDa that was identified as 3-oxoacyl-CoA thiolase A (thiolase A) by N-terminal amino acid sequencing. The second enzyme preparation consisted of a 58- and a 46-kDa band. The 58-kDa polypeptide reacted with antibodies raised against either sterol carrier protein 2 or the thiolase domain of sterol carrier protein 2/3-oxoacyl-CoA thiolase (SCP-2/thiolase), formerly also called sterol carrier protein X, whereas the 46-kDa polypeptide reacted only with the antibodies raised against the thiolase domain. Internal peptide sequencing confirmed that the 58-kDa polypeptide is SCP-2/thiolase and that the 46-kDa polypeptide is the thiolase domain of SCP-2/thiolase. Thiolase A catalyzed the cleavage of short, medium, and long straight chain 3-oxoacyl-CoAs, medium chain 3-oxoacyl-CoAs being the best substrates. The enzyme was inactive with the 2-methyl-branched 3-oxo-2-methylpalmitoyl-CoA and with the bile acid intermediate 24-oxo-trihydroxycoprostanoyl-CoA. SCP-2/thiolase was active with medium and long straight chain 3-oxoacyl-CoAs but also with the 2-methyl-branched 3-oxoacyl-CoA and the bile acid intermediate. In peroxisomal extracts, more than 90% of the thiolase activity toward straight chain 3-oxoacyl-CoAs was associated with thiolase A. Kinetic parameters (Km and Vmax) were determined for each enzyme with the different substrates. Our results indicate the following: 1) the two (main) thiolases present in peroxisomes from normal rat liver are thiolase A and SCP-2/thiolase; 2) thiolase A is responsible for the thiolytic cleavage of straight chain 3-oxoacyl-CoAs; and 3) SCP-2/thiolase is responsible for the thiolytic cleavage of the 3-oxoacyl-CoA derivatives of 2-methyl-branched fatty acids and the side chain of cholesterol.
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Affiliation(s)
- V D Antonenkov
- Katholieke Universiteit Leuven, Departement Moleculaire Celbiologie, Afdeling, Campus Gasthuisberg (O & N), Herestraat 49, B-3000 Leuven, Belgium
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