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Zhao X, Huang W, Guo J, Ji N, Feng J, Shi Y, Chen K, Zou J. PLAAT1 promotes p53 degradation via autophagy-lysosome pathway in zebrafish. FISH & SHELLFISH IMMUNOLOGY 2022; 125:48-53. [PMID: 35526800 DOI: 10.1016/j.fsi.2022.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/24/2022] [Accepted: 05/02/2022] [Indexed: 06/14/2023]
Abstract
PLAAT1 belongs to the PLAAT family and plays regulatory roles in cell growth, tumor suppression and phospholipid metabolism. However, whether PLAAT1 is involved in p53 mediated signaling has not been investigated. Here, we report that PLAAT1 promotes degradation of p53 in zebrafish. We found that the plaat1 gene was constitutively expressed in tissues including liver, kidney, spleen, intestine, eye and brain, with relative higher expression levels detected in the brain and eye. Overexpression of plaat1 led to inhibition of p53 and tnfα mRNA expression. Furthermore, it was shown that PLAAT1 interacted with p53 to facilitate p53 degradation via autophagy-lysosome dependent pathway. Our work indicates that PLAAT1 is involved in the interplay between p53 mediated cellular responses and autophagy.
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Affiliation(s)
- Xin Zhao
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Wenji Huang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Jiahong Guo
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Ning Ji
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Jianhua Feng
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Yanjie Shi
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Kangyong Chen
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China
| | - Jun Zou
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
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2
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Chatterjee S, Zhou J, Dasgupta R, Cramer-Blok A, Timmer M, van der Stelt M, Ubbink M. Protein Dynamics Influence the Enzymatic Activity of Phospholipase A/Acyltransferases 3 and 4. Biochemistry 2021; 60:1178-1190. [PMID: 33749246 PMCID: PMC8154263 DOI: 10.1021/acs.biochem.0c00974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 03/04/2021] [Indexed: 11/29/2022]
Abstract
Phospholipase A/acyltransferase 3 (PLAAT3) and PLAAT4 are enzymes involved in the synthesis of bioactive lipids. Despite sequential and structural similarities, the two enzymes differ in activity and specificity. The relation between the activity and dynamics of the N-terminal domains of PLAAT3 and PLAAT4 was studied. PLAAT3 has a much higher melting temperature and exhibits less nanosecond and millisecond dynamics in the active site, in particular in loop L2(B6), as shown by NMR spectroscopy and molecular dynamics calculations. Swapping the L2(B6) loops between the two PLAAT enzymes results in strongly increased phospholipase activity in PLAAT3 but no reduction in PLAAT4 activity, indicating that this loop contributes to the low activity of PLAAT3. The results show that, despite structural similarity, protein dynamics differ substantially between the PLAAT variants, which can help to explain the activity and specificity differences.
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Affiliation(s)
- Soumya
Deep Chatterjee
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Juan Zhou
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Rubin Dasgupta
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Anneloes Cramer-Blok
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Monika Timmer
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Mario van der Stelt
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
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3
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Parmer C, De Sousa-Coelho AL, Cheng HS, Daher G, Burkart A, Dreyfuss JM, Pan H, Prenner JC, Keilson JM, Pande R, Henkin S, Feinberg MW, Patti ME, Creager MA. Skeletal muscle expression of adipose-specific phospholipase in peripheral artery disease. Vasc Med 2020; 25:401-410. [PMID: 32853041 DOI: 10.1177/1358863x20947467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Flow-limiting atherosclerotic lesions of arteries supplying the limbs are a cause of symptoms in patients with peripheral artery disease (PAD). Musculoskeletal metabolic factors also contribute to the pathophysiology of claudication, which is manifest as leg discomfort that impairs walking capacity. Accordingly, we conducted a case-control study to determine whether skeletal muscle metabolic gene expression is altered in PAD. Calf skeletal muscle gene expression of patients with PAD and healthy subjects was analyzed using microarrays. The top-ranking gene differentially expressed between PAD and controls (FDR < 0.001) was PLA2G16, which encodes adipose-specific phospholipase A2 (AdPLA) and is implicated in the maintenance of insulin sensitivity and regulation of lipid metabolism. Differential expression was confirmed by qRT-PCR; PLA2G16 was downregulated by 68% in patients with PAD (p < 0.001). Expression of Pla2g16 was then measured in control (db/+) and diabetic (db/db) mice that underwent unilateral femoral artery ligation. There was significantly reduced expression of Pla2g16 in the ischemic leg of both control and diabetic mice (by 51%), with significantly greater magnitude of reduction in the diabetic mice (by 79%). We conclude that AdPLA is downregulated in humans with PAD and in mice with hindlimb ischemia. Reduced AdPLA may contribute to impaired walking capacity in patients with PAD via its effects on skeletal muscle metabolism. Further studies are needed to fully characterize the role of AdPLA in PAD and to investigate its potential as a therapeutic target for alleviating symptoms of claudication.
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Affiliation(s)
- Caitlin Parmer
- Department of Medicine, Stanford University Medical Center, Palo Alto, CA, USA
| | | | - Henry S Cheng
- Cardiovascular Division, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Grace Daher
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Alison Burkart
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Jonathan M Dreyfuss
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Hui Pan
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Joshua C Prenner
- Department of Medicine, McGaw Medical Center of Northwestern University, Chicago, IL, USA
| | | | - Reena Pande
- Cardiovascular Division, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Stanislav Henkin
- Heart and Vascular Center, Dartmouth-Hitchcock Medical Center and Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Mark W Feinberg
- Cardiovascular Division, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Mary Elizabeth Patti
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Mark A Creager
- Heart and Vascular Center, Dartmouth-Hitchcock Medical Center and Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
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4
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Zhou J, Mock ED, Martella A, Kantae V, Di X, Burggraaff L, Baggelaar MP, Al-Ayed K, Bakker A, Florea BI, Grimm SH, den Dulk H, Li CT, Mulder L, Overkleeft HS, Hankemeier T, van Westen GJP, van der Stelt M. Activity-Based Protein Profiling Identifies α-Ketoamides as Inhibitors for Phospholipase A2 Group XVI. ACS Chem Biol 2019; 14:164-169. [PMID: 30620559 PMCID: PMC6379856 DOI: 10.1021/acschembio.8b00969] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/08/2019] [Indexed: 02/07/2023]
Abstract
Phospholipase A2, group XVI (PLA2G16) is a thiol hydrolase from the HRASLS family that regulates lipolysis in adipose tissue and has been identified as a host factor enabling the cellular entry of picornaviruses. Chemical tools are essential to visualize and control PLA2G16 activity, but they have not been reported to date. Here, we show that MB064, which is a fluorescent lipase probe, also labels recombinant and endogenously expressed PLA2G16. Competitive activity-based protein profiling (ABPP) using MB064 enabled the discovery of α-ketoamides as the first selective PLA2G16 inhibitors. LEI110 was identified as a potent PLA2G16 inhibitor ( Ki = 20 nM) that reduces cellular arachidonic acid levels and oleic acid-induced lipolysis in human HepG2 cells. Gel-based ABPP and chemical proteomics showed that LEI110 is a selective pan-inhibitor of the HRASLS family of thiol hydrolases (i.e., PLA2G16, HRASLS2, RARRES3 and iNAT). Molecular dynamic simulations of LEI110 in the reported crystal structure of PLA2G16 provided insight in the potential ligand-protein interactions to explain its binding mode. In conclusion, we have developed the first selective inhibitor that can be used to study the cellular role of PLA2G16.
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Affiliation(s)
- Juan Zhou
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Elliot D. Mock
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Andrea Martella
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Vasudev Kantae
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
- Department
of Analytical BioSciences and Metabolomics, Leiden Academic Centre
for Drug Research, Leiden University, Leiden, The Netherlands
| | - Xinyu Di
- Department
of Analytical BioSciences and Metabolomics, Leiden Academic Centre
for Drug Research, Leiden University, Leiden, The Netherlands
| | - Lindsey Burggraaff
- Department
of Computational Drug Discovery, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Marc P. Baggelaar
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Karol Al-Ayed
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Alexander Bakker
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Bogdan I. Florea
- Department
of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Sebastian H. Grimm
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Hans den Dulk
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Chun T. Li
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Laura Mulder
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Herman S. Overkleeft
- Department
of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Thomas Hankemeier
- Department
of Analytical BioSciences and Metabolomics, Leiden Academic Centre
for Drug Research, Leiden University, Leiden, The Netherlands
| | - Gerard J. P. van Westen
- Department
of Computational Drug Discovery, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Mario van der Stelt
- Department
of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
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5
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Mardian EB, Bradley RM, Duncan RE. The HRASLS (PLA/AT) subfamily of enzymes. J Biomed Sci 2015; 22:99. [PMID: 26503625 PMCID: PMC4624172 DOI: 10.1186/s12929-015-0210-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/16/2015] [Indexed: 12/11/2022] Open
Abstract
The H-RAS-like suppressor (HRASLS) subfamily consists of five enzymes (1–5) in humans and three (1, 3, and 5) in mice and rats that share sequence homology with lecithin:retinol acyltransferase (LRAT). All HRASLS family members possess in vitro phospholipid metabolizing abilities including phospholipase A1/2 (PLA1/2) activities and O-acyltransferase activities for the remodeling of glycerophospholipid acyl chains, as well as N-acyltransferase activities for the production of N-acylphosphatidylethanolamines. The in vivo biological activities of the HRASLS enzymes have not yet been fully investigated. Research to date indicates involvement of this subfamily in a wide array of biological processes and, as a consequence, these five enzymes have undergone extensive rediscovery and renaming within different fields of research. This review briefly describes the discovery of each of the HRASLS enzymes and their role in cancer, and discusses the biochemical function of each enzyme, as well as the biological role, if known. Gaps in current understanding are highlighted and suggestions for future research directions are discussed.
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Affiliation(s)
- Emily B Mardian
- Department of Kinesiology, University of Waterloo, BMH 2415, Waterloo, ON, N2L 3G1, Canada.
| | - Ryan M Bradley
- Department of Kinesiology, University of Waterloo, BMH 2415, Waterloo, ON, N2L 3G1, Canada.
| | - Robin E Duncan
- Department of Kinesiology, University of Waterloo, BMH 1110, Waterloo, ON, N2L 3G1, Canada.
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6
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Pang XY, Cao J, Addington L, Lovell S, Battaile KP, Zhang N, Rao JLUM, Dennis EA, Moise AR. Structure/function relationships of adipose phospholipase A2 containing a cys-his-his catalytic triad. J Biol Chem 2012; 287:35260-35274. [PMID: 22923616 DOI: 10.1074/jbc.m112.398859] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Adipose phospholipase A(2) (AdPLA or Group XVI PLA(2)) plays an important role in the onset of obesity by suppressing adipose tissue lipolysis. As a consequence, AdPLA-deficient mice are resistant to obesity induced by a high fat diet or leptin deficiency. It has been proposed that AdPLA mediates its antilipolytic effects by catalyzing the release of arachidonic acid. Based on sequence homology, AdPLA is part of a small family of acyltransferases and phospholipases related to lecithin:retinol acyltransferase (LRAT). To better understand the enzymatic mechanism of AdPLA and LRAT-related proteins, we solved the crystal structure of AdPLA. Our model indicates that AdPLA bears structural similarity to proteins from the NlpC/P60 family of cysteine proteases, having its secondary structure elements configured in a circular permutation of the classic papain fold. Using both structural and biochemical evidence, we demonstrate that the enzymatic activity of AdPLA is mediated by a distinctive Cys-His-His catalytic triad and that the C-terminal transmembrane domain of AdPLA is required for the interfacial catalysis. Analysis of the enzymatic activity of AdPLA toward synthetic and natural substrates indicates that AdPLA displays PLA(1) in addition to PLA(2) activity. Thus, our results provide insight into the enzymatic mechanism and biochemical properties of AdPLA and LRAT-related proteins and lead us to propose an alternate mechanism for AdPLA in promoting adipose tissue lipolysis that is not contingent on the release of arachidonic acid and that is compatible with its combined PLA(1)/A(2) activity.
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Affiliation(s)
- Xiao-Yan Pang
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Linsee Addington
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Scott Lovell
- Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047
| | - Kevin P Battaile
- Industrial Macromolecular Crystallography Association Collaborative Access Team (IMCA-CAT), Hauptman-Woodward Medical Research Institute, Argonne, Illinois 60439
| | - Na Zhang
- Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047
| | - J L Uma Maheswar Rao
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Edward A Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Alexander R Moise
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045.
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7
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Wong J, Sia YY, Misso NL, Aggarwal S, Ng A, Bhoola KD. Effects of the demethylating agent, 5-azacytidine, on expression of the kallikrein-kinin genes in carcinoma cells of the lung and pleura. PATHOLOGY RESEARCH INTERNATIONAL 2011; 2011:167046. [PMID: 21904690 PMCID: PMC3166727 DOI: 10.4061/2011/167046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 06/12/2011] [Indexed: 12/25/2022]
Abstract
Tissue kallikrein (KLK1) and plasma kallikrein (KLKB1) may regulate the growth and proliferation of tumours of the lung and pleura, through the generation of kinin peptides that signal through the kinin B(1) (BDKRB1) and B(2) (BDKRB2) receptors. The development and progression of cancer results from genetic mutations, as well as epigenetic changes that include methylation of DNA at CpG islands. The aim of this study was to assess whether expression of the kallikrein-kinin genes in lung cancer and mesothelioma cells is regulated by DNA methylation. Quantitative reverse transcriptase-PCR and immunocytochemistry showed differences in the basal expression of the kallikrein-kinin genes and proteins in lung carcinoma and mesothelioma cells, compared with non-malignant lung epithelial and mesothelial cells, respectively. Following treatment with the demethylating agent, 5-azacytidine (5-AZA), KLKB1 mRNA expression was consistently increased in both lung carcinoma and mesothelioma cells, whereas KLK1, BDKRB1 and BDKRB2 mRNA expression was decreased or unchanged. Increased expression of KLKB1 after 5-AZA treatment suggests it may function as a tumour suppressor gene in cancers of the lung and pleura. Studies on DNA methylation of the kallikrein-kinin genes will enhance understanding of their role in carcinogenesis and provide insights into the importance of kallikreins as tumour biomarkers.
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Affiliation(s)
- Joshua Wong
- Lung Institute of Western Australia and Centre for Asthma, Allergy and Respiratory Research, The University of Western Australia, Ground Floor, E Block, Sir Charles Gairdner Hospital, Perth, WA 6009, Australia
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8
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Ren X, Lin J, Jin C, Xia B. Solution structure of the N-terminal catalytic domain of human H-REV107 - A novel circular permutated NlpC/P60 domain. FEBS Lett 2010; 584:4222-6. [DOI: 10.1016/j.febslet.2010.09.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/03/2010] [Accepted: 09/04/2010] [Indexed: 12/15/2022]
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9
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Duncan RE, Sarkadi-Nagy E, Jaworski K, Ahmadian M, Sul HS. Identification and functional characterization of adipose-specific phospholipase A2 (AdPLA). J Biol Chem 2008; 283:25428-25436. [PMID: 18614531 PMCID: PMC2533091 DOI: 10.1074/jbc.m804146200] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 07/09/2008] [Indexed: 12/24/2022] Open
Abstract
Phospholipases A(2) (PLA(2)s) catalyze hydrolysis of fatty acids from the sn-2 position of phospholipids. Here we report the identification and characterization of a membrane-associated intracellular calcium-dependent, adipose-specific PLA(2) that we named AdPLA (adipose-specific phospholipase A(2)). We found that AdPLA was highly expressed specifically in white adipose tissue and was induced during preadipocyte differentiation into adipocytes. Clearance of AdPLA by immunoprecipitation significantly decreased PLA activity in white adipose tissue lysates but had no effect on liver lysates, where expression was hardly detectable. In characterizing AdPLA, we employed radiochemical assays with TLC analysis of the enzyme activity of lysates from COS-7 cells overexpressing AdPLA. For kinetic studies, we produced purified recombinant AdPLA for use in a lipoxidase-coupled spectrophotometric assay. AdPLA generated free fatty acid and lysophospholipid from phosphatidylcholine with a preference for hydrolysis at the sn-2 position. Although we found low but detectable lysophospholipase activity, AdPLA showed no significant activity against a variety of other lipid substrates. Calcium was found to activate AdPLA but was not essential for activity. Studies with known phospholipase inhibitors, including bromoenolactone, methyl arachidonyl fluorophosphate, AACOCF(3), 7,7-dimethyl-5,8-eicosadienoic acid, and thioetheramide, supported that AdPLA is a phospholipase. Mutational studies showed that His-23 and Cys-113 are critical for activity of AdPLA and suggested that AdPLA is likely a His/Cys PLA(2). Overall, although AdPLA is similar to other histidine phospholipases in pH and calcium dependence, AdPLA showed different characteristics in many regards, including predicted catalytic mechanism. AdPLA may therefore represent the first member of a new group of PLA(2)s, group XVI.
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Affiliation(s)
- Robin E Duncan
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Eszter Sarkadi-Nagy
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Kathy Jaworski
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Maryam Ahmadian
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Hei Sook Sul
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720.
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10
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Yang Y, Haitchi HM, Cakebread J, Sammut D, Harvey A, Powell RM, Holloway JW, Howarth P, Holgate ST, Davies DE. Epigenetic mechanisms silence a disintegrin and metalloprotease 33 expression in bronchial epithelial cells. J Allergy Clin Immunol 2008; 121:1393-9, 1399.e1-14. [PMID: 18423563 DOI: 10.1016/j.jaci.2008.02.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 02/25/2008] [Accepted: 02/26/2008] [Indexed: 10/22/2022]
Abstract
BACKGROUND A disintegrin and metalloprotease 33 (ADAM33) polymorphism is strongly associated with asthma and bronchial hyperresponsiveness. Although considered to be a mesenchymal cell-specific gene, recent reports have suggested epithelial expression of ADAM33 in patients with severe asthma. OBJECTIVES Because dysregulated expression of ADAM33 can contribute to disease pathogenesis, we characterized the mechanism or mechanisms that control its transcription and investigated ADAM33 expression in bronchial biopsy specimens and brushings from healthy and asthmatic subjects. METHODS The ADAM33 promoter and CpG island methylation were analyzed by using bioinformatics, luciferase reporters, and bisulfite sequencing of genomic DNA. Epithelial-mesenchymal transition was induced by using TGF-beta1. ADAM33 mRNA was scrutinized in bronchial biopsy specimens and brushings by using reverse transcriptase-quantitative polymerase chain reaction, melt-curve analysis, and direct sequencing. RESULTS The predicted ADAM33 promoter (-550 to +87) had promoter transcriptional activity. Bisulfite sequencing showed that the predicted promoter CpG island (-362 to +80) was hypermethylated in epithelial cells but hypomethylated in ADAM33-expressing fibroblasts. Treatment of epithelial cells with 5-aza-deoxycytidine caused demethylation of the CpG island and induced ADAM33 expression. In contrast, phenotypic transformation of epithelial cells through a TGF-beta-induced epithelial-mesenchymal transition was insufficient to induce ADAM33 expression. ADAM33 mRNA was confirmed in bronchial biopsy specimens, but no validated signal was detected in bronchial brushings from healthy or asthmatic subjects. CONCLUSION The ADAM33 gene contains a regulatory CpG island within its promoter, the methylation status of which tightly controls its expression in a cell type-specific manner. ADAM33 repression is a stable feature of airway epithelial cells, irrespective of disease.
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Affiliation(s)
- Youwen Yang
- Brooke Laboratories, Division of Infection, Inflammation and Repair, School of Medicine, University of Southampton, Southampton, United Kingdom
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11
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Yanatatsaneejit P, Chalermchai T, Kerekhanjanarong V, Shotelersuk K, Supiyaphun P, Mutirangura A, Sriuranpong V. Promoter hypermethylation of CCNA1, RARRES1, and HRASLS3 in nasopharyngeal carcinoma. Oral Oncol 2008; 44:400-6. [PMID: 17689134 DOI: 10.1016/j.oraloncology.2007.05.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 05/15/2007] [Accepted: 05/17/2007] [Indexed: 10/23/2022]
Abstract
In search for putative tumor suppressor genes critical of nasopharyngeal carcinoma (NPC), we analyzed the available information from the expression profiling in conjunction with the comprehensive alleotyping published data relevant to this malignancy. Integration of this information suggested eight potential candidate tumor suppressor genes, CCNA1, HRASLS3, RARRES1, CLMN, EML1, TSC22, LOH11CR2A and MCC. However, to confirm the above observations, we chose to investigate if promoter hypermethylation of these candidate genes would be one of the mechanisms responsible for the de-regulation of gene expression in NPC in addition to the loss of genetic materials. In this study, we detected consistent hypermethylation of the 5' element of CCNA1, RARRES1, and HRASLS in NPC tissues with prevalence of 48%, 51%, and 17%, respectively. Moreover, we found a similar profile of promoter hypermethylation in primary cultured NPC cells but none in normal nasopharyngeal epithelium or leukocytes, which further substantiate our hypothesis. Our data indicate that CCNA1, RARRES1, and HRASLS3 may be the putative tumor suppressor genes in NPC.
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12
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Ou CC, Hsu SC, Hsieh YH, Tsou WL, Chuang TC, Liu JY, Kao MC. Downregulation of HER2 by RIG1 involves the PI3K/Akt pathway in ovarian cancer cells. Carcinogenesis 2008; 29:299-306. [PMID: 18174256 DOI: 10.1093/carcin/bgm263] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Interferon-gamma (IFN-gamma) is known to downregulate HER2 oncoprotein (p185(HER2) or briefly p185) in prostate cancer cells. We demonstrate that the IFN-gamma-induced retinoid-inducible gene 1 (RIG1) acts as a transrepressor of p185. Furthermore, we exhibit that RIG1 downregulates the activated (phosphorylated) form of p185 and phosphoinositide-3 kinase (PI3K)/serine/threonine-specific protein kinase (Akt) and the mammalian target of rapamycin (mTOR), downstream substrates of HER2. We also elucidate that heregulin (HRG) specifically restores the activation of p185 and Akt after their activities are reduced by RIG1. Additionally, expression of vascular endothelial growth factor (VEGF) increases through the HER2- and Akt/mTOR-signaling pathways, indicating that VEGF is downregulated by RIG1 within the cell. These findings suggest that RIG1 plays a role in IFN-gamma-mediated therapy by downregulating p185 and its downstream PI3K/Akt/mTOR/VEGF-signaling pathway. These results may provide a new therapeutic mechanism for the clinical use of IFN-gamma and RIG1.
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Affiliation(s)
- Chien-Chih Ou
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan 114, Republic of China
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13
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Griffin MJ, Wong RHF, Pandya N, Sul HS. Direct interaction between USF and SREBP-1c mediates synergistic activation of the fatty-acid synthase promoter. J Biol Chem 2006; 282:5453-67. [PMID: 17197698 DOI: 10.1074/jbc.m610566200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To understand the molecular mechanisms underlying transcriptional activation of fatty-acid synthase (FAS), we examined the relationship between upstream stimulatory factor (USF) and SREBP-1c, two transcription factors that we have shown previously to be critical for FAS induction by feeding/insulin. Here, by using a combination of tandem affinity purification and coimmunoprecipitation, we demonstrate, for the first time, that USF and SREBP-1 interact in vitro and in vivo. Glutathione S-transferase pulldown experiments with various USF and sterol regulatory element-binding protein (SREBP) deletion constructs indicate that the basic helix-loop-helix domain of USF interacts directly with the basic helix-loop-helix and an N-terminal region of SREBP-1c. Furthermore, cotransfection of USF and SREBP-1c with an FAS promoter-luciferase reporter construct in Drosophila SL2 cells results in highly synergistic activation of the FAS promoter. We also show similar cooperative activation of the mitochondrial glycerol-3-phosphate acyltransferase promoter by USF and SREBP-1c. Chromatin immunoprecipitation analysis of mouse liver demonstrates that USF binds constitutively to the mitochondrial glycerol 3-phosphate acyltransferase promoter during fasting/refeeding in vivo, whereas binding of SREBP-1 is observed only during refeeding, in a manner identical to that of the FAS promoter. In addition, we show that the synergy we have observed depends on the activation domains of both proteins and that mutated USF or SREBP lacking the N-terminal activation domain could inhibit the transactivation of the other. Closely positioned E-boxes and sterol regulatory elements found in the promoters of several lipogenic genes suggest a common mechanism of induction by feeding/insulin.
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Affiliation(s)
- Michael J Griffin
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720, USA
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14
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Cozzi SJ, Parsons PG, Ogbourne SM, Pedley J, Boyle GM. Induction of senescence in diterpene ester-treated melanoma cells via protein kinase C-dependent hyperactivation of the mitogen-activated protein kinase pathway. Cancer Res 2006; 66:10083-91. [PMID: 17047072 DOI: 10.1158/0008-5472.can-06-0348] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The diterpene ester PEP005 is a novel anticancer agent that activates protein kinase C (PKC) and induces cell death in melanoma at high doses. We now describe the in vitro cytostatic effects of PEP005 and the diterpene ester phorbol 12-myristate 13-acetate, observed in 20% of human melanoma cell lines. Primary cultures of normal human neonatal fibroblasts were resistant to growth arrest, indicating a potential for tumor selectivity. Sensitive cell lines were induced to senesce and exhibited a G(1) and G(2)-M arrest. There was sustained expression of p21(WAF1/CIP1), irreversible dephosphorylation of the retinoblastoma protein, and transcriptional silencing of E2F-responsive genes in sensitive cell lines. Activation of mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK) kinase (MEK) 1/2 by PKC was required for diterpene ester-induced senescence. Expression profiling revealed that the MAP kinase inhibitor HREV107 was expressed at a higher transcript level in resistant compared with sensitive cell lines. We propose that activation of PKC overstimulates the RAS/RAF/MEK/ERK pathway, resulting in molecular changes leading to the senescent phenotype.
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Affiliation(s)
- Sarah-Jane Cozzi
- Melanoma Genomics Group, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
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15
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Nazarenko I, Kristiansen G, Fonfara S, Guenther R, Gieseler C, Kemmner W, Schafer R, Petersen I, Sers C. H-REV107-1 stimulates growth in non-small cell lung carcinomas via the activation of mitogenic signaling. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 169:1427-39. [PMID: 17003497 PMCID: PMC1698850 DOI: 10.2353/ajpath.2006.051341] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2006] [Indexed: 01/02/2023]
Abstract
H-REV107-1, a known member of the class II tumor suppressor gene family, is involved in the regulation of differentiation and survival. We analyzed H-REV107-1 in non-small cell lung carcinomas, in normal lung, and in immortalized and tumor-derived cell lines. Sixty-eight percent of lung tumors revealed positive H-REV107-1-specific staining. Furthermore, survival analysis demonstrated a significant association of cytoplasmic H-REV107-1 with decreased patient survival. This suggested that H-REV107-1, known as a tumor suppressor, plays a different role in non-small cell lung carcinomas. Knock-down of H-REV107-1 expression in lung carcinoma cells inhibited anchorage-dependent and anchorage-independent growth whereas overexpression of H-REV107-1 induced tumor cell proliferation. Consistent with results of the survival analysis, cytoplasmic localization of the protein was essential for this growth-inducing function. Analysis of signaling pathways potentially involved in this process demonstrated that overexpression of H-REV107-1 stimulated RAS-GTPase activity, ERK1,2 phosphorylation, and caveolin-1 expression in the cell lines analyzed. These results indicate that H-REV107-1 is deficient in its function as a tumor suppressor in non-small cell lung carcinomas and is required for proliferation and anchorage-independent growth in cells expressing high levels of the protein, thus contributing to tumor progression in a subset of non-small cell lung carcinomas.
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Affiliation(s)
- Irina Nazarenko
- Institute of Pathology, Charité Universitaetsmedizin Berlin Schumannstr. 20/21, D-10117 Berlin, Germany
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16
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Jiang SY, Wu MS, Chen LM, Hung MW, Lin HE, Chang GG, Chang TC. Identification and characterization of the retinoic acid response elements in the human RIG1 gene promoter. Biochem Biophys Res Commun 2005; 331:630-9. [PMID: 15850806 DOI: 10.1016/j.bbrc.2005.03.214] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Indexed: 12/11/2022]
Abstract
The expression of retinoic acid-induced gene 1 (RIG1), a class II tumor suppressor gene, is induced in cells treated with retinoids. RIG1 has been shown to express ubiquitously and the increased expression of this gene appears to suppress cell proliferation. Recent studies also demonstrated that this gene may play an important role in cell differentiation and the progression of cancer. In spite of the remarkable regulatory role of this protein, the molecular mechanism of RIG1 expression induced by retinoids remains to be clarified. The present study was designed to study the molecular mechanism underlying the all-trans retinoic acid (atRA)-mediated induction of RIG1 gene expression. Polymerase chain reaction was used to generate a total of 10 luciferase constructs that contain various fragments of the RIG1 5'-genomic region. These constructs were then transfected into human gastric cancer SC-M1 and breast cancer T47D cells for transactivation analysis. atRA exhibited a significant induction in luciferase activity only through the -4910/-5509 fragment of the 5'-genomic region of RIG1 gene relative to the translation initiation site. Further analysis of this promoter fragment indicated that the primary atRA response region is located in between -5048 and -5403 of the RIG1 gene. Within this region, a direct repeat sequence with five nucleotide spacing, 5'-TGACCTctattTGCCCT-3' (DR5, -5243/-5259), and an inverted repeat sequence with six nucleotide spacing, 5'-AGGCCAtggtaaTGGCCT-3' (IR6, -5323/-5340), were identified. Deletion and mutation of the DR5, but not the IR6 element, abolished the atRA-mediated activity. Electrophoretic mobility shift assays with nuclear extract from atRA-treated cells indicated the binding of retinoic acid receptor (RAR) and retinoid X receptor (RXR) heterodimers specifically to this response element. In addition to the functional DR5, the region contains many other potential sequence elements that are required to maximize the atRA-mediated induction. Taken together, we have identified and characterized the functional atRA response element that is responsible for the atRA-mediated induction of RIG1 gene.
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Affiliation(s)
- Shun-Yuan Jiang
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan, ROC
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17
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Lotz K, Kellner T, Heitmann M, Nazarenko I, Noske A, Malek A, Gontarewicz A, Schäfer R, Sers C. Suppression of theTIG3 tumor suppressor gene in human ovarian carcinomas is mediatedvia mitogen-activated kinase-dependent and -independent mechanisms. Int J Cancer 2005; 116:894-902. [PMID: 15856468 DOI: 10.1002/ijc.21127] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The TIG3 gene is a retinoic acid inducible class II tumor suppressor gene downregulated in several human tumors and malignant cell lines. Diminished TIG3 expression correlates with decreased differentiation whereas forced expression of TIG3 suppresses oncogenic signaling pathways and subsequently induces differentiation or apoptosis in tumor cells. Analysis of TIG3 mRNA expression in a large set of cDNA pools derived from matched tumor and normal human tissues showed a significant downregulation of TIG3 in 29% of the cDNA samples obtained from ovarian carcinomas. Using in situ hybridization, we demonstrated expression of TIG3 in the epithelial lining of 7 normal ovaries but loss of TIG3 expression in 15/19 of human ovarian carcinoma tissues. In SKOV-3, CAOV-3 and ES-2 ovarian carcinoma cell lines, downregulation of TIG3 mRNA was reversible and dependent on an activated MEK-ERK signaling pathway. Re-expression of TIG3 mRNA in these cells upon specific interference with the MEK-pathway was correlated with growth inhibition of the cells. In OVCAR-3 and A27/80 ovarian carcinoma cells, TIG3 suppression is MEK-ERK independent, but expression could be reconstituted upon interferon gamma (IFNgamma) induction. Overexpression of TIG3 in A27/80 ovarian carcinoma cells significantly impaired cell growth and despite increased mRNA levels, TIG3 protein was hardly detectable. These results suggest that TIG3 is negatively regulated by an activated MEK-ERK signaling pathway. Further mechanisms must interfere with TIG3 expression that are independent of MEK and partially include interferon-responsive components.
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Affiliation(s)
- Kristina Lotz
- Institute of Pathology, University Hospital Charité, Berlin, Germany
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18
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Nakagawachi T, Soejima H, Urano T, Zhao W, Higashimoto K, Satoh Y, Matsukura S, Kudo S, Kitajima Y, Harada H, Furukawa K, Matsuzaki H, Emi M, Nakabeppu Y, Miyazaki K, Sekiguchi M, Mukai T. Silencing effect of CpG island hypermethylation and histone modifications on O6-methylguanine-DNA methyltransferase (MGMT) gene expression in human cancer. Oncogene 2004; 22:8835-44. [PMID: 14647440 DOI: 10.1038/sj.onc.1207183] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
O6-methylguanine-DNA methyltransferase (MGMT) repairs the cytotoxic and mutagenic O6-alkylguanine produced by alkylating agents such as chemotherapeutic agents and mutagens. Recent studies have shown that in a subset of tumors, MGMT expression is inversely linked to hypermethylation of the CpG island in the promoter region; however, how the epigenetic silencing mechanism works, as it relates to hypermethylation, was still unclear. To understand the mechanism, we examined the detailed methylation status of the whole island with bisulfite-sequencing in 19 MGMT non-expressed cancer cell lines. We found two highly methylated regions in the island. One was upstream of exon 1, including minimal promoter, and the other was downstream, including enhancer. Reporter gene assay showed that methylation of both the upstream and downstream regions suppressed luciferase activity drastically. Chromatin immunoprecipitation assay revealed that histone H3 lysine 9 was hypermethylated throughout the island in the MGMT negative line, whereas acetylation on H3 and H4 and methylation on H3 lysine 4 were at significantly high levels outside the minimal promoter in the MGMT-expressed line. Furthermore, MeCP2 preferentially bound to the CpG-methylated island in the MGMT negative line. Given these results, we propose a model for gene silencing of MGMT that is dependent on the epigenetic state in cancer.
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Affiliation(s)
- Tetsuji Nakagawachi
- Division of Molecular Biology and Genetics, Department of Biomolecular Sciences, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan
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Baker EK, El-Osta A. The rise of DNA methylation and the importance of chromatin on multidrug resistance in cancer. Exp Cell Res 2003; 290:177-94. [PMID: 14567978 DOI: 10.1016/s0014-4827(03)00342-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In recent years, the different classes of drugs and regimens used clinically have provided an improvement in tumour management. However, treatment is often palliative for the majority of cancer patients. Transformed cells respond poorly to chemotherapy mainly due to the development of the multidrug resistance (MDR) phenotype. Response to treatment does not generally result in complete remission and disease cure is uncommon for patients presenting with advanced stage cancer. Successful treatment of cancer requires a clearer understanding of chemotherapeutic resistance. Here, we examine what is known of one of the most extensively studied mechanisms of cellular drug resistance. The human multidrug resistance gene 1 (MDR1) is associated with expression of p-glycoprotein (Pgp). A transmembrane protein, Pgp acts as an efflux pump and reduces intracellular drug levels and thus its effectiveness as an antitumor agent. The precise mechanism of transcriptional regulation has been unclear due to the complex regulatory nature of the gene. It has become increasingly apparent that trans-activation or genetic amplification is by no means the only mechanism of activation. Consequently, alternative pathways have received more attention in the area of epigenetics to help explain transcriptional competence at a higher level of organization. The goal of this article is to highlight important findings in the field of methylation and explain how they impinge on MDR1 gene regulation. In this review, we cover the current information and postulate that epigenetic modification of MDR1 chromatin influences gene transcription in leukaemia. Finally, we explore transcriptional regulation and highlight recent progress with engineered ZFP's (zinc finger proteins).
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Affiliation(s)
- Emma K Baker
- The Alfred Medical Research and Education Precinct, Baker Medical Research Institute, Epigenetics in Human Health and Disease Laboratory, Second Floor, Commercial Road, Prahran, Victoria 3181, Australia
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Abstract
Nuclear transfer experiments have demonstrated that epigenetic mechanisms operate to limit gene expression during animal development. In somatic cells, silenced genes are associated with defined chromatin states which are characterised by hypermethylation of DNA, hypoacetylation of histones and specific patterns of methylation at distinct residues of the N-terminal tails of histone H3 and H4. This review describes the role of the DNA methylation-mediated repression system (Dnmt1's, MeCPs and MBDs and associated chromatin remodelling activities) in animal development. DNA methylation is essential for normal vertebrate development but has distinct regulatory roles in non-mammalian and mammalian vertebrates. In mammals, DNA methylation has an additional role in regulating imprinting. This suggests that epigenetic regulation is plastic in its application and should be considered in a developmental context that may be species specific.
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Affiliation(s)
- Richard R Meehan
- Genes and Development Group, Department of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland EH8 9XD, UK
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