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Kunadis E, Lakiotaki E, Korkolopoulou P, Piperi C. Targeting post-translational histone modifying enzymes in glioblastoma. Pharmacol Ther 2020; 220:107721. [PMID: 33144118 DOI: 10.1016/j.pharmthera.2020.107721] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/08/2020] [Accepted: 10/27/2020] [Indexed: 12/30/2022]
Abstract
Glioblastoma (GBM) is the most common primary brain tumor in adults, and the most lethal form of glioma, characterized by variable histopathology, aggressiveness and poor clinical outcome and prognosis. GBMs constitute a challenge for oncologists because of their molecular heterogeneity, extensive invasion, and tendency to relapse. Glioma cells demonstrate a variety of deregulated genomic pathways and extensive interplay with epigenetic alterations. Epigenetic modifications have emerged as essential players in GBM research, with biomarker potential for tumor classification and prognosis and for drug targeting. Histone posttranslational modifications (PTMs) are crucial regulators of chromatin architecture and gene expression, playing a pivotal role in malignant transformation, tumor development and progression. Alteration in the expression of genes coding for lysine and arginine methyltransferases (G9a, SUV39H1 and SETDB1) and acetyltransferases and deacetylases (KAT6A, SIRT2, SIRT7, HDAC4, 6, 9) contribute to GBM pathogenesis. In addition, proteins of the sumoylation pathway are upregulated in GBM cell lines, including E1 (SAE1), E2 (Ubc9) components, and a SUMO-specific protease (SENP1). Preclinical and clinical studies are currently in progress targeting epigenetic enzymes in gliomas, including a new generation of histone deacetylase (HDAC), protein arginine methyltransferase (PRMT) and bromodomain (BRD) inhibitors. Herein, we provide an update on recent advances in glioma epigenetic research, focusing on the role of histone modifications and the use of epigenetic therapy as a valid treatment option for glioblastoma.
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Affiliation(s)
- Elena Kunadis
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Eleftheria Lakiotaki
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Penelope Korkolopoulou
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece.
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Ma C, Pathak C, Jang S, Lee SJ, Nam M, Kim SJ, Im H, Lee BJ. Structure of Thermoplasma volcanium Ard1 belongs to N-acetyltransferase family member suggesting multiple ligand binding modes with acetyl coenzyme A and coenzyme A. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1790-7. [PMID: 25062911 DOI: 10.1016/j.bbapap.2014.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 12/18/2022]
Abstract
Acetylation and deacetylation reactions result in biologically important modifications that are involved in normal cell function and cancer development. These reactions, carried out by protein acetyltransferase enzymes, act by transferring an acetyl group from acetyl-coenzymeA (Ac-CoA) to various substrate proteins. Such protein acetylation remains poorly understood in Archaea, and has been only partially described. Information processing in Archaea has been reported to be similar to that in eukaryotes and distinct from the equivalent bacterial processes. The human N-acetyltransferase Ard1 (hArd1) is one of the acetyltransferases that has been found to be overexpressed in various cancer cells and tissues, and knockout of the hArd1 gene significantly reduces growth rate of the cancer cell lines. In the present study, we determined the crystal structure of Thermoplasma volcanium Ard1 (Tv Ard1), which shows both ligand-free and multiple ligand-bound forms, i.e.,Ac-CoA- and coenzyme A (CoA)-bound forms. The difference between ligand-free and ligand-bound chains in the crystal structure was used to search for the interacting residues. The re-orientation and position of the loop between β4 and α3 including the phosphate-binding loop (P-loop) were observed, which are important for the ligand interaction. In addition, a biochemical assay to determine the N-acetyltransferase activity of Tv Ard1 was performed using the T.volcanium substrate protein Alba (Tv Alba). Taken together, the findings of this study elucidate ligand-free form of Tv Ard1 for the first time and suggest multiple modes of binding with Ac-CoA and CoA.
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Affiliation(s)
- Chao Ma
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Chinar Pathak
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Sunbok Jang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Sang Jae Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Minjoo Nam
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Soon-Jong Kim
- Department of Chemistry, Mokpo National University, Chonnam, Republic of Korea
| | - Hookang Im
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Bong-Jin Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea.
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Abstract
Nuclear receptors (NRs) represent a vital class of ligand-activated transcription factors responsible for coordinately regulating the expression of genes involved in numerous biological processes. Transcriptional regulation by NRs is conducted through interactions with multiple coactivator or corepressor complexes that modify the chromatin environment to facilitate or inhibit RNA polymerase II binding and transcription initiation. In recent years, studies have identified specific biological roles for cofactors mediating NR signaling through epigenetic modifications such as acetylation and methylation of histones. Intriguingly, genome-wide analysis of NR and cofactor localization has both confirmed findings from single-gene studies and revealed new insights into the relationships between NRs, cofactors and target genes in determining gene expression. Here, we review recent developments in the understanding of epigenetic regulation by NRs across the genome within the context of the well-established background of cofactor complexes and their roles in histone modification.
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Affiliation(s)
- Christopher D Green
- Chinese Academy of Sciences Key Laboratory of Molecular Developmental Biology, Center for Molecular Systems Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Datun Road, Beijing, 100101, China
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences–MaxPlanck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China
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Abstract
Acetylation is an essential post-translational modification in which an acetyl group is covalently conjugated to a protein substrate. Histone acetylation was first proposed nearly half a century ago by Dr. Vincent Allfrey. Subsequent studies have shown that acetylated core histones are often associated with transcriptionally active chromatin. Acetylation at lysine residues of histone tails neutralizes the positive charge, which decreases the binding ability to DNA and increases the accessibility of transcription factors and co-activators to the chromatin template. In addition to histones, a number of non-histone substrates are acetylated. Acetylation of non-histone proteins governs biological processes, including cellular proliferation and survival, transcriptional activity, and intracellular trafficking. We demonstrated that acetylation of transcription factors can regulate cellular growth. Further, we have shown that nuclear receptors are acetylated at a phylogenetically conserved motif. Since our initial observations with the estrogen and androgen receptors, more than a dozen nuclear receptors have been shown to function as substrates for acetyltransferases with a variety of new methods (Fig. 11.1). This chapter focuses on the protocol used in the studies of NR acetylation and de-acetylation. We will discuss the potential pitfalls of each method.
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Affiliation(s)
- Chenguang Wang
- Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Kim DW, Kim JY, Moon JH, Kim KB, Kim TS, Hong SJ, Cheon YP, Pak JH, Seo SB. Transcriptional induction of minichromosome maintenance protein 7 (Mcm7) in human cholangiocarcinoma cells treated with Clonorchis sinensis excretory-secretory products. Mol Biochem Parasitol 2010; 173:10-6. [PMID: 20236609 DOI: 10.1016/j.molbiopara.2010.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 03/07/2010] [Accepted: 03/08/2010] [Indexed: 11/16/2022]
Abstract
Clonorchiasis is an infection associated with bile duct malignancy and subsequent development of cholangiocarcinoma. This disease is mainly caused by Clonorchis sinensis worms and their excretory-secretory products (ESP). However, the precise molecular mechanisms of carcinogenesis remain to be determined. Previously, we established differential gene expression profiles from microarrays containing 23,920 human genes of known function in a human cholangiocarcinoma cell line, HuCCT1, treated with ESP. Among the upregulated genes, we focused on minichromosome maintenance protein 7 (Mcm7), which is implicated in various cancer types, and analyzed transcriptional regulation mediated by ESP to further elucidate its role in cholangiocarcinoma development. Global histone acetylation levels were increased in ESP-treated cells, along with histone acetyltransferase (HAT) protein expression. Detailed promoter analysis using reporter and chromatin immunoprecipitation assays revealed that transcriptional activation of Mcm7 is mediated by HAT recruitment to the promoter region upon C. sinensis ESP treatment. These findings contribute to clarification of the intrinsic mechanism underlying the cellular carcinogenesis process stimulated by Mcm7 in C. sinensis-treated host cells.
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Affiliation(s)
- Dong-Wook Kim
- Research Center for Biomolecules and Biosystems, Department of Life Science, Chung-Ang University, Seoul, South Korea
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Tikoo K, Kumar P, Gupta J. Rosiglitazone synergizes anticancer activity of cisplatin and reduces its nephrotoxicity in 7, 12-dimethyl benz{a}anthracene (DMBA) induced breast cancer rats. BMC Cancer 2009; 9:107. [PMID: 19356226 PMCID: PMC2676298 DOI: 10.1186/1471-2407-9-107] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 04/08/2009] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Antineoplastic drug cisplatin remains the drug of choice for various solid tumours including breast cancer. But dose dependent nephrotoxicity is the major drawback in majority of platinum based chemotherapy regimens. Recent reports have shown that inflammatory pathways are the main offender for cisplatin induced nephrotoxicity. The present study was undertaken to assess the effect of rosiglitazone, a PPARgamma agonist and an anti-inflammatory agent, on cisplatin induced nephrotoxicity, and its anticancer activity in DMBA induced breast cancer rats. METHODS Mammary tumours were induced in female Sprague-Dawley rats by feeding orally with dimethylbenz [a]anthracene (DMBA) (60 mg/kg). Cisplatin induced nephropathy was assessed by measurements of blood urea nitrogen, albumin and creatinine levels. Posttranslational modifications of histone H3, mitogen-activated protein (MAP) kinase p38 expression and PPAR-gamma expression were examined by western blotting. RESULTS Our data shows involvement of TNF-alpha in preventing cisplatin induced nephrotoxicity by rosiglitazone. Rosiglitazone pre-treatment to cisplatin increases the expression of p38, PPAR-gamma in mammary tumours and shows maximum tumour reduction. Furthermore, cisplatin induced changes in histone acetylation, phosphorylation and methylation of histone H3 in mammary tumours was ameliorated by pre-treatment of rosiglitazone. Suggesting, PPAR-gamma directly or indirectly alters aberrant gene expression in mammary tumours by changing histone modifications. CONCLUSION To best of our knowledge this is the first report which shows that pre-treatment of rosiglitazone synergizes the anticancer activity of cisplatin and minimizes cisplatin induced nephrotoxicity in DMBA induced breast cancer.
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Affiliation(s)
- Kulbhushan Tikoo
- Laboratory of Chromatin Biology, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, SAS Nagar, Punjab, India.
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Generation of novel monoclonal antibodies and their application for detecting ARD1 expression in colorectal cancer. Cancer Lett 2008; 264:83-92. [DOI: 10.1016/j.canlet.2008.01.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2007] [Revised: 01/09/2008] [Accepted: 01/10/2008] [Indexed: 11/20/2022]
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Popov VM, Wang C, Andrew Shirley L, Rosenberg A, Li S, Nevalainen M, Fu M, Pestell RG. The functional significance of nuclear receptor acetylation. Steroids 2007; 72:221-30. [PMID: 17291555 PMCID: PMC2694494 DOI: 10.1016/j.steroids.2006.12.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 12/04/2006] [Accepted: 12/04/2006] [Indexed: 01/02/2023]
Abstract
The endocrine signaling governing nuclear receptor (NR) function has been known for several decades to play a crucial role in the onset and progression of several tumor types. Notably among these are the estrogen receptor (ER) in breast cancer and androgen receptor (AR) in prostate cancer. Other nuclear receptors may be involved in cancer progression including the peroxisome-proliferator activating receptor gamma (PPARgamma), which has been implicated in breast, thyroid, and colon cancers. These NR are phylogenetically conserved modular transcriptional regulators, which like histones, undergo post-translational modification by acetylation, phosphorylation and ubiquitination. Importantly, the transcriptional activity of the receptors is governed by the coactivator p300, the activity of which is thought to be rate-limiting in the activity of these receptors. Histone acetyltransferases (HATs) and histone deacetylases (HDACs), modify histones by adding or removing an acetyl group from the epsilon amino group of lysines within an evolutionarily conserved lysine motif. Histone acetylation results in changes in chromatin structure in response to specific signals. These enzymes can also directly catalyze the NRs themselves, thus modifying signals at the receptor level. The post-translational modification of NR which is regulated by hormones, alters the NR function toward a growth promoting receptor. The deacetylation of NR is mediated by TSA-sensitive and NAD-dependent deacetylases. The regulation of NR by NAD-dependent enzymes provides a direct link between intracellular metabolism and hormone signaling.
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Affiliation(s)
- Vladimir M. Popov
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Chenguang Wang
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - L. Andrew Shirley
- Department of Surgery, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Anne Rosenberg
- Department of Surgery, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Shengwen Li
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Marja Nevalainen
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Maofu Fu
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
| | - Richard G. Pestell
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
- Department of Medical Oncology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10 Street, Philadelphia, PA 19107
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9
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Chun KH, Cho SJ, Choi JS, Kim SH, Kim KW, Lee SK. Differential regulation of splicing, localization and stability of mammalian ARD1235 and ARD1225 isoforms. Biochem Biophys Res Commun 2007; 353:18-25. [PMID: 17161380 DOI: 10.1016/j.bbrc.2006.11.131] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 11/15/2006] [Indexed: 11/25/2022]
Abstract
ARD1 protein is a mammalian gene product homologous to a yeast Ard1p (Arrest defective 1 protein) acetyltransferase. Although two alternative splicing products of ARD1, ARD1(235) and ARD1(225), were reported in mouse, only ARD1(235) orthologue was reported in humans. Here we show that ARD1(225) is not expressed in humans, suggesting that factors regulating alternative splicing of ARD1 may have evolved differently between species. In human cells, hARD1(235) is shown to be present in both nucleus and cytoplasm. However, in mouse cells, mARD1(235) and mARD1(225) proteins are localized to the nucleus and cytoplasm, respectively. Moreover, during apoptosis, ARD1(235) and ARD1(225) isoforms are destabilized by different mechanisms in a species-specific manner and dependent on destabilizing reagents. These results indicate that ARD1(235) and ARD1(225) isoforms may have different activities and function in different subcellular compartments of mammalian cells.
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Affiliation(s)
- Kwang-Hoon Chun
- Division of Pharmaceutical Biosciences, College of Pharmacy, The Research Institute for Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
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10
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Abstract
The position effect variegation in Drosophila and Schizosaccharomyces pombe, and higher-order chromatin structure regulation in yeast, is orchestrated by modifier genes of the Su(var) group, (e.g., histone deacetylases ([HDACs]), protein phosphatases) and enhancer E(Var) group (e.g., ATP [adenosine 5'-triphosphate]-dependent nucleosome remodeling proteins). Higher-order chromatin structure is regulated in part by covalent modification of the N-terminal histone tails of chromatin, and histone tails in turn serve as platforms for recruitment of signaling modules that include nonhistone proteins such as heterochromatin protein (HP1) and NuRD. Because the enzymes governing chromatin structure through covalent modifications of histones (acetylation, methylation, phosphorylation, ubiquitination) can also target nonhistone substrates, a mechanism is in place by which epigenetic regulatory processes can affect the function of these alternate substrates. The posttranslational modification of histones, through phosphorylation and acetylation at specific residues, alters chromatin structure in an orchestrated manner in response to specific signals and is considered the basis of a "histone code." In an analogous manner, specific residues within transcription factors form a signaling module within the transcription factor to determine genetic target specificity and cellular fate. The architecture of these signaling cascades in transcription factors (SCITs) are poorly understood. The regulation of estrogen receptor (ERalpha) by enzymes that convey epigenetic signals is carefully orchestrated and is reviewed here.
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Affiliation(s)
- Jennifer E Leader
- Kimmel Cancer Center, Department of Cancer Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
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11
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Fu M, Liu M, Sauve AA, Jiao X, Zhang X, Wu X, Powell MJ, Yang T, Gu W, Avantaggiati ML, Pattabiraman N, Pestell TG, Wang F, Quong AA, Wang C, Pestell RG. Hormonal control of androgen receptor function through SIRT1. Mol Cell Biol 2006; 26:8122-35. [PMID: 16923962 PMCID: PMC1636736 DOI: 10.1128/mcb.00289-06] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The NAD-dependent histone deacetylase Sir2 plays a key role in connecting cellular metabolism with gene silencing and aging. The androgen receptor (AR) is a ligand-regulated modular nuclear receptor governing prostate cancer cellular proliferation, differentiation, and apoptosis in response to androgens, including dihydrotestosterone (DHT). Here, SIRT1 antagonists induce endogenous AR expression and enhance DHT-mediated AR expression. SIRT1 binds and deacetylates the AR at a conserved lysine motif. Human SIRT1 (hSIRT1) repression of DHT-induced AR signaling requires the NAD-dependent catalytic function of hSIRT1 and the AR lysine residues deacetylated by SIRT1. SIRT1 inhibited coactivator-induced interactions between the AR amino and carboxyl termini. DHT-induced prostate cancer cellular contact-independent growth is also blocked by SIRT1, providing a direct functional link between the AR, which is a critical determinant of progression of human prostate cancer, and the sirtuins.
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Affiliation(s)
- Maofu Fu
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Leader JE, Wang C, Fu M, Pestell RG. Epigenetic regulation of nuclear steroid receptors. Biochem Pharmacol 2006; 72:1589-96. [PMID: 16844098 DOI: 10.1016/j.bcp.2006.05.024] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 05/25/2006] [Accepted: 05/30/2006] [Indexed: 01/06/2023]
Abstract
Histone modifier proteins have come to the forefront in the study of gene regulation. It is now known that histone methyltransferases, acetytransferases, kinases, ubiquitinases, deacetylases and demethylases orchestrate expression of target genes by modifying both histone and non-histone proteins. The nuclear receptor (NR) superfamily govern such diverse biological processes as development, physiology and disease, including human cancer. The involvement of NR in complexes with coactivators and corepressors is necessary for regulation of target genes. This review focuses on the newly recognized interactions between the NR and histone modifying enzymes. In addition to regulating histones, the histone modifying proteins directly modify and thereby regulate NR activity. In the same manner that signaling platforms exist within the histone tails that are post-translationally processed by histone modifying proteins, cascades of post-translational modification have been identified within the NR that coordinate their activity. This review focuses on the regulation of the NR estrogen receptor (ERalpha), androgen receptor (AR) and peroxisome proliferator activated receptor-gamma (PPARgamma), given their role in tumor onset and progression.
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Affiliation(s)
- Jennifer E Leader
- Kimmel Cancer Center, Department of Cancer Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
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Qiu P, Ritchie RP, Gong XQ, Hamamori Y, Li L. Dynamic changes in chromatin acetylation and the expression of histone acetyltransferases and histone deacetylases regulate the SM22alpha transcription in response to Smad3-mediated TGFbeta1 signaling. Biochem Biophys Res Commun 2006; 348:351-8. [PMID: 16876108 DOI: 10.1016/j.bbrc.2006.07.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Accepted: 07/05/2006] [Indexed: 11/25/2022]
Abstract
TGFbeta1 plays critical roles in stimulating smooth muscle gene transcription during myofibroblast and smooth muscle cell (SMC) differentiation. Increasing evidence demonstrates that histone modification plays important roles in regulating gene transcription. Here, we investigated the effect of changes in the expression of histone acetyltransferases (HAT) or histone deacetylases (HDAC) on TGFbeta1-induced SM22 promoter activities. We found that overexpressing HAT proteins such as p300 and CBP enhances TGFbeta1-induced SM22 promoter activities; conversely, overexpressing HAT inhibitor such as Twist1 (but not Twist2/Dermo-1) and E1A suppresses this effect of TGFbeta1. We also found that TSA, a HDAC inhibitor that stimulates histone acetylation of the SM22alpha locus, further enhances the transactivational activity of Smad2, Smad3 and Smad4, and relieves the inhibitory effect of Smad6, Smad7, and the dominant negative mutants of Smads. TGFbeta1 also stimulates the association of Smad3 (a potent transactivator for the SM22 promoter) and p300 by co-immunoprecipitation assay. In contrast, overexpressing HDAC 1-6 inhibits TGFbeta1-induced as well as Smad3 and myocardin-activated SM22 promoter. Moreover, chromatin immunoprecipitation (ChIP) assays show that TGFbeta1 induces histone acetylation at the SM22alpha locus. This study demonstrates that the balance of HAT and HDAC expression affects TGFbeta1-induced SM22alpha transcription; TGFbeta1-induced SM22alpha transcription is accompanied by histone hyperacetylation at the SM22alpha locus. This study provides the first evidence showing that histone hyperacetylation of the SM22 promoter is a target of TGFbeta1 signaling, suggesting that modulation of histone acetylation is involved in the molecular mechanisms of TGFbeta1-regulated SMC gene transcription.
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Affiliation(s)
- Ping Qiu
- Department of Internal Medicine, Wayne State University, Detroit, MI 48201, USA
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Gong J, Zhu J, Goodman OB, Pestell RG, Schlegel PN, Nanus DM, Shen R. Activation of p300 histone acetyltransferase activity and acetylation of the androgen receptor by bombesin in prostate cancer cells. Oncogene 2006; 25:2011-21. [PMID: 16434977 DOI: 10.1038/sj.onc.1209231] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Androgen receptor signaling in prostate cancer cells is augmented by the androgen receptor (AR) coactivator p300, which transactivates and acetylates the AR in the presence of dihydrotestosterone (DHT). As prostate cancer (PC) cells progress to androgen independence, AR signaling remains intact, indicating that other factors stimulate AR activities in the absence of androgen. We previously reported that neuropeptide growth factors could transactivate the AR in the presence of very low concentrations of DHT. Here, we examine the involvement of p300 in neuropeptide activation of AR signaling. Transfection of increasing concentrations of p300 in the presence of bombesin into PC-3 cells resulted in a linear increase in AR transactivation, suggesting that p300 acts as a coactivator in neuropeptide-mediated AR transactivation. P300 is endowed with histone acetyltransferase (HAT) activity. Therefore, we examine the effect of bombesin on p300 HAT activity. At 4 h after the addition of bombesin, p300 HAT activity increased 2.0-fold (P<0.01). Incubation with neutral endopeptidase, which degrades bombesin, or bombesin receptor antagonists blocked bombesin-induced p300 HAT activity. To explore the potential signaling pathways involved in bombesin-induced p300 HAT activity, we examined Src and PKCdelta pathways that mediate bombesin signaling. Inhibitors of Src kinase activity or Src kinase siRNA blocked bombesin-induced p300 HAT activity, whereas PKCdelta inhibitors or PKCdelta siRNA significantly increased bombesin-induced p300 HAT activity suggesting that Src kinase and PKCdelta kinase are involved in the regulation of p300 HAT activity. As AR is acetylated in the presence of 100 nM DHT, we next examined whether bombesin-induced p300 HAT activity would result in enhanced AR acetylation. Bombesin-induced AR acetylation at the same motif KLKK observed in DHT-induced acetylation. Elimination of p300 using p300 siRNA reduced AR acetylation, demonstrating that AR acetylation was mediated by p300. AR acetylation results in AR transactivation and the expression of the AR-regulated gene prostate-specific antigen (PSA). Therefore, we examined bombesin-induced AR transactivation and PSA expression in the presence and absence of p300 siRNA and found inhibition of p300 expression reduced bombesin-induced AR transactivation and PSA expression. Together these results demonstrate that bombesin, via Src and PKCdelta signaling pathways, activates p300 HAT activity which leads to enhanced acetylation of AR resulting in increased expression of AR-regulated genes.
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Affiliation(s)
- J Gong
- Department of Urology, Weill Medical College of Cornell University, New York, NY 10021, USA
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15
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Khan SA, Park SW, Huq MDM, Wei LN. Ligand-independent orphan receptor TR2 activation by phosphorylation at the DNA-binding domain. Proteomics 2006; 6:123-30. [PMID: 16317770 DOI: 10.1002/pmic.200500068] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In a previous report we demonstrated protein kinase C (PKC)-mediated phosphorylation of the ligand-binding domain (LBD) of orphan nuclear receptor TR2. In this report, we provide the evidence of PKC-mediated phosphorylation of the DNA-binding domain (DBD) of TR2. Two PKC target sites were predicted within the DBD, at Ser-170 and Ser-185, but only Ser-185 was confirmed by MS. Phosphorylation of DBD facilitated DNA binding of the TR2 receptor and its recruiting of coactivator p300/CBP-associated factor (P/CAF). Ser-185 was required for DNA binding, whereas both Ser-170 and Ser-185 were necessary for receptor interaction with P/CAF. The P/CAF-interacting domain of TR2 was located in its DBD. A double mutant (Ser-170 and Ser-185) of TR2 significantly lowered the activation of its target gene RARbeta2. This study provides the first evidence for ligand-independent activation of TR2 orphan receptor through PTM at the DBD, which enhanced its DNA-binding ability and interaction with coactivator P/CAF.
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MESH Headings
- Base Sequence
- Binding Sites
- Blotting, Western
- Chromatography, Liquid
- DNA/metabolism
- DNA Primers
- Electrophoretic Mobility Shift Assay
- Immunoprecipitation
- Ligands
- Mutagenesis, Site-Directed
- Phosphorylation
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Member 14
- Receptors, Virus/chemistry
- Receptors, Virus/genetics
- Receptors, Virus/metabolism
- Serine/metabolism
- Spectrometry, Mass, Electrospray Ionization
- Transcription, Genetic
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Affiliation(s)
- Shaukat Ali Khan
- Department of Pharmacology, University of Minnesota Medical School, 321 Church Street SE, Minneapolis, MN 55455, USA
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16
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Abstract
The comprehensive study of proteomes has become an important part of attempts to uncover the systemic properties of biological systems. Proteomics provides data of a quality which increasingly fulfills strict requirements of systems biology for quantitative and qualitative information. Notably, proteomics can generate rich datasets that describe dynamic changes of proteomes. On the other hand, large-scale modeling requires the development of mathematic tools that are adequate for the processing of largely uncertain biological data. In this review, recent developments that pave the way for the integration of proteomics into systems biology are discussed. These developments include the standardization of data acquisition and presentation, the increased comprehensiveness of proteomics studies in description of functional status, localization and dynamics of proteins, and advanced modeling approaches.
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17
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Arnesen T, Anderson D, Baldersheim C, Lanotte M, Varhaug J, Lillehaug J. Identification and characterization of the human ARD1-NATH protein acetyltransferase complex. Biochem J 2005; 386:433-43. [PMID: 15496142 PMCID: PMC1134861 DOI: 10.1042/bj20041071] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Protein acetyltransferases and deacetylases have been implicated in oncogenesis, apoptosis and cell cycle regulation. Most of the protein acetyltransferases described acetylate epsilon-amino groups of lysine residues within proteins. Mouse ARD1 (homologue of yeast Ard1p, where Ard1p stands for arrest defective 1 protein) is the only known protein acetyltransferase catalysing acetylation of proteins at both alpha-(N-terminus) and epsilon-amino groups. Yeast Ard1p interacts with Nat1p (N-acetyltransferase 1 protein) to form a functional NAT (N-acetyltransferase). We now describe the human homologue of Nat1p, NATH (NAT human), as the partner of the hARD1 (human ARD1) protein. Included in the characterization of the NATH and hARD1 proteins is the following: (i) endogenous NATH and hARD1 proteins are expressed in human epithelial, glioma and promyelocytic cell lines; (ii) NATH and hARD1 form a stable complex, as investigated by reciprocal immunoprecipitations followed by MS analysis; (iii) NATH-hARD1 complex expresses N-terminal acetylation activity; (iv) NATH and hARD1 interact with ribosomal subunits, indicating a co-translational acetyltransferase function; (v) NATH is localized in the cytoplasm, whereas hARD1 localizes both to the cytoplasm and nucleus; (vi) hARD1 partially co-localizes in nuclear spots with the transcription factor HIF-1alpha (hypoxia-inducible factor 1alpha), a known epsilon-amino substrate of ARD1; (vii) NATH and hARD1 are cleaved during apoptosis, resulting in a decreased NAT activity. This study identifies the human homologues of the yeast Ard1p and Nat1p proteins and presents new aspects of the NATH and hARD1 proteins relative to their yeast homologues.
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Affiliation(s)
- Thomas Arnesen
- *Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway
- †Department of Surgical Sciences, University of Bergen and Haukeland University Hospital, N-5021 Bergen, Norway
| | - Dave Anderson
- ‡Institute of Molecular Biology, University of Oregon, Eugene, OR 97403-1229, U.S.A
| | | | - Michel Lanotte
- §INSERM U496, Centre G. Hayem, Hopital Saint-Louis, 1, Avenue Claude Vellefaux, 75010 Paris, France
| | - Jan E. Varhaug
- †Department of Surgical Sciences, University of Bergen and Haukeland University Hospital, N-5021 Bergen, Norway
| | - Johan R. Lillehaug
- *Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway
- To whom correspondence should be addressed (email )
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18
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Fu M, Wang C, Rao M, Wu X, Bouras T, Zhang X, Li Z, Jiao X, Yang J, Li A, Perkins ND, Thimmapaya B, Kung AL, Munoz A, Giordano A, Lisanti MP, Pestell RG. Cyclin D1 represses p300 transactivation through a cyclin-dependent kinase-independent mechanism. J Biol Chem 2005; 280:29728-42. [PMID: 15951563 DOI: 10.1074/jbc.m503188200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclin D1 encodes a regulatory subunit, which with its cyclin-dependent kinase (Cdk)-binding partner forms a holoenzyme that phosphorylates and inactivates the retinoblastoma protein. In addition to its Cdk binding-dependent functions, cyclin D1 regulates cellular differentiation in part by modifying several transcription factors and nuclear receptors. The molecular mechanism through which cyclin D1 regulates the function of transcription factors involved in cellular differentiation remains to be clarified. The histone acetyltransferase protein p300 is a co-integrator required for regulation of multiple transcription factors. Here we show that cyclin D1 physically interacts with p300 and represses p300 transactivation. We demonstrated further that the interaction of the two proteins occurs at the peroxisome proliferator-activated receptor gamma-responsive element of the lipoprotein lipase promoter in the context of the local chromatin structure. We have mapped the domains in p300 and cyclin D1 involved in this interaction. The bromo domain and cysteine- and histidine-rich domains of p300 were required for repression by cyclin D1. Cyclin D1 repression of p300 was independent of the Cdk- and retinoblastoma protein-binding domains of cyclin D1. Cyclin D1 inhibits histone acetyltransferase activity of p300 in vitro. Microarray analysis identified a signature of genes repressed by cyclin D1 and induced by p300 that promotes cellular differentiation and induces cell cycle arrest. Together, our results suggest that cyclin D1 plays an important role in cellular proliferation and differentiation through regulation of p300.
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Affiliation(s)
- Maofu Fu
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, Washington, DC 20057, USA
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19
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Bouras T, Fu M, Sauve AA, Wang F, Quong AA, Perkins ND, Hay RT, Gu W, Pestell RG. SIRT1 Deacetylation and Repression of p300 Involves Lysine Residues 1020/1024 within the Cell Cycle Regulatory Domain 1. J Biol Chem 2005; 280:10264-76. [PMID: 15632193 DOI: 10.1074/jbc.m408748200] [Citation(s) in RCA: 264] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The SIR2 family of nicotinamide adenosine dinucleotide (NAD)-dependent deacetylases modulates diverse biological functions in different species, including longevity, apoptosis, cell cycle exit, and cellular differentiation. SIRT1, the closest mammalian ortholog of the yeast SIR2 (silent information regulator 2) gene, represses several transcription factors, including p53, NFkappaB and forkhead proteins. The p300 protein serves as a rate-limiting transcriptional cointegrator of diverse transcription factors either to activate or to repress transcription through modular subdomains. Herein, SIRT1 physically interacted with and repressed p300 transactivation, requiring the NAD-dependent deacetylase activity of SIRT1. SIRT1 repression involved the CRD1 transcriptional repression domain of p300. Two residues within the CRD1 domain (Lys-1020 and Lys-1024) were required for SIRT1 repression and served as substrates for SIRT1 deacetylation. These residues also serve as acceptor lysines for modification by the ubiquitin-like SUMO protein. The SUMO-specific protease SSP3 relieved SIRT1 repression of p300. SSP3 antagonism of SIRT1 required the SUMO-deconjugating function of SSP3. Thus, p300 serves as a deacetylase substrate for SIRT1 through a conserved SUMO consensus motif. Because p300 is a limiting transcriptional cofactor, deacetylation and repression of p300 by SIRT1 may serve an important integration point during metabolism and cellular differentiation.
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Affiliation(s)
- Toula Bouras
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Rd.,Washington, DC 20057, USA
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20
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Fu M, Rao M, Bouras T, Wang C, Wu K, Zhang X, Li Z, Yao TP, Pestell RG. Cyclin D1 inhibits peroxisome proliferator-activated receptor gamma-mediated adipogenesis through histone deacetylase recruitment. J Biol Chem 2005; 280:16934-41. [PMID: 15713663 DOI: 10.1074/jbc.m500403200] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The cyclin D1 gene encodes the labile serum-inducible regulatory subunit of a holoenzyme that phosphorylates and inactivates the retinoblastoma protein. Overexpression of cyclin D1 promotes cellular proliferation and normal physiological levels of cyclin D1 function to inhibit adipocyte differentiation in vivo. We have previously shown that cyclin D1 inhibits peroxisome proliferator-activated receptor (PPAR)gamma-dependent activity through a cyclin-dependent kinase- and retinoblastoma protein-binding-independent mechanism. In this study, we determined the molecular mechanism by which cyclin D1 regulated PPARgamma function. Herein, murine embryonic fibroblast (MEF) differentiation by PPARgamma ligand was associated with a reduction in histone deacetylase (HDAC1) activity. Cyclin D1-/- MEFs showed an increased propensity to undergo differentiation into adipocytes. Genetic deletion of cyclin D1 reduced HDAC1 activity. Reconstitution of cyclin D1 into the cyclin D1-/- MEFs increased HDAC1 activity and blocked PPARgamma-mediated adipogenesis. PPARgamma activity was enhanced in cyclin D1-/- cells. Reintroduction of cyclin D1 inhibited basal and ligand-induced PPARgamma activity and enhanced HDAC repression of PPARgamma activity. Cyclin D1 bound HDAC in vivo and preferentially physically associated with HDAC1, HDAC2, HDAC3, and HDAC5. Chromatin immunoprecipitation assay demonstrated that cyclin D1 enhanced recruitment of HDAC1 and HDAC3 and histone methyltransferase SUV39H1 to the PPAR response element of the lipoprotein lipase promoter and decreased acetylation of total histone H3 and histone H3 lysine 9. Collectively, these studies suggest an important role of cyclin D1 in regulation of PPARgamma-mediated adipocyte differentiation through recruitment of HDACs to regulate PPAR response element local chromatin structure and PPARgamma function.
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Affiliation(s)
- Maofu Fu
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, Washington, D. C. 20057, USA
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21
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Fu M, Wang C, Zhang X, Pestell RG. Acetylation of nuclear receptors in cellular growth and apoptosis. Biochem Pharmacol 2004; 68:1199-208. [PMID: 15313417 DOI: 10.1016/j.bcp.2004.05.037] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2004] [Accepted: 05/24/2004] [Indexed: 11/28/2022]
Abstract
Post-translational modification of chromatin histones governs a key mechanism of transcriptional regulation. Histone acetylation, together with methylation, phosphorylation, ubiquitylation, sumoylation, glycosylation, and ADP ribosylation, modulate the activity of many genes by modifying both core histones and non-histone transcription factors. Epigenetic protein modification plays an important role in multiple cellular processes including DNA repair, protein stability, nuclear translocation, protein-protein interactions, and in regulation of cellular proliferation, differentiation and apoptosis. Histone acetyltransferases modify histones, coactivators, nuclear transport proteins, structural proteins, cell cycle components and transcription factors including p53 and nuclear receptors. The estrogen, PPARgamma and androgen receptor are members of the nuclear receptor (NR) superfamily. The androgen receptor (AR) and estrogen receptor alpha (ERalpha) are directly acetylated by histone acetyltransferases at a motif that is conserved between species and other NR. Point mutations at the lysine residue within the acetylation motif of the AR and ERalpha have been identified in prostate cancer as well as in breast cancer tissue. Acetylation of the NR governs ligand sensitivity and hormone antagonist responses. The AR is acetylated by p300, P/CAF and TIP60 and acetylation of the AR regulates co-regulator recruitment and growth properties of the receptors in cultured cells and in vivo. AR acetylation mimic mutants convey reduced apoptosis and enhanced growth properties correlating with altered promoter specificity for cell-cycle target genes. Cell-cycle control proteins, including cyclins, in turn alter the access of transcription factors and nuclear receptors to the promoters of target genes.
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Affiliation(s)
- Maofu Fu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Rd NW, Washington, DC 20057, USA
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22
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Fu M, Rao M, Wu K, Wang C, Zhang X, Hessien M, Yeung YG, Gioeli D, Weber MJ, Pestell RG. The androgen receptor acetylation site regulates cAMP and AKT but not ERK-induced activity. J Biol Chem 2004; 279:29436-49. [PMID: 15123687 DOI: 10.1074/jbc.m313466200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The androgen receptor (AR) regulates ligand-dependent gene transcription upon binding specific DNA sequences. The AR conveys both trans-activation and trans-repression functions, which together contribute to prostate cellular growth, differentiation, and apoptosis. Like histone H3, the AR is post-translationally modified by both acetylation and phosphorylation. The histone acetyltransferase p300 transactivates the AR and directly acetylates the AR in vitro at a conserved motif. Point mutations of the AR acetylation motif that abrogate acetylation reduce trans-activation by p300 without affecting the trans-repression function of the AR. The current studies assessed the functional relationship between acetylation and phosphorylation of the AR. Herein trans-activation of the AR acetylation site mutants were enhanced by the p42/p44 MAPK pathway but were defective in regulation by protein kinase A (PKA) signaling. PKA inhibition augmented ARwt activity but not AR acetylation mutant gene reporter activity and association at an androgen response element in chromatin immunoprecipitation assays. Mutations of the lysine residues at the AR acetylation site reduced trichostatin A (TSA) responsiveness and ligand-induced phosphorylation of the AR. The AR acetylation site mutant formed ligand-induced phosphorylation-dependent isoforms with distinguishable characteristics from wild type AR as determined with two-dimensional electrophoresis. Conversely, point mutation of a subset of AR phosphorylation sites reduced trichostatin A responsiveness and trans-activation by histone acetyltransferases. Together these studies suggest that acetylation and phosphorylation of the AR are linked events and that the conserved AR lysine motif contributes to a select subset of pathways governing AR activity.
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Affiliation(s)
- Maofu Fu
- Department of Oncology, Georgetown University Medical Center, Washington, D C 20057, USA
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23
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Abstract
Heritable and reversible changes in gene expression can occur without alterations in DNA sequence largely dependent upon the position of a gene within an accessible (euchromatic) chromatin environment. This position effect variegation in Drosophila and S. pombe, and higher order chromatin structure regulation in yeast, is orchestrated by modifier genes of the Su(var) group (e.g. histone deacetylases (HDACs), protein phosphatases) and enhancer E(var) group (e.g. ATP-dependent nucleosome remodeling proteins). Higher order chromatin structure is regulated in part by covalent modification of the N-terminal histone tails of chromatin and histone tails in turn serve as platforms for recruitment of signaling modules that include non-histone proteins such as HP1 and NuRD. As the enzymes governing chromatin structure through covalent modifications of histones (acetylation, methylation, phosphorylation, ubiquitination) can also target non-histone substrates, a mechanism is in place by which epigenetic regulatory processes can affect the function of these alternate substrates. The nuclear receptor (NR) superfamily consists of conserved modular transcriptional regulators. Herein, we review the functional properties of nuclear receptors regulated by their direct acetylation including ligand-dependent activation, cellular growth and apoptosis.
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Affiliation(s)
- Maofu Fu
- Department of Oncology, Lombardi Cancer Center, Georgetown University, Research Building Rm E501, 3970 Reservoir Road NW, Box 571468, Washington, DC 20057-1468, USA
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24
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Neumeister P, Pixley FJ, Xiong Y, Xie H, Wu K, Ashton A, Cammer M, Chan A, Symons M, Stanley ER, Pestell RG. Cyclin D1 governs adhesion and motility of macrophages. Mol Biol Cell 2003; 14:2005-15. [PMID: 12802071 PMCID: PMC165093 DOI: 10.1091/mbc.02-07-0102] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The cyclin D1 gene encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the retinoblastoma protein, thereby promoting cell-cycle progression. Cyclin D1 is overexpressed in hematopoetic and epithelial malignancies correlating with poor prognosis and metastasis in several cancer types. Because tumor-associated macrophages have been shown to enhance malignant progression and metastasis, and cyclin D1-deficient mice are resistant to oncogene-induced malignancies, we investigated the function of cyclin D1-/- bone marrow-derived macrophages. Cyclin D1 deficiency increased focal complex formation at the site of substratum contact, and enhanced macrophage adhesion, yielding a flattened, circular morphology with reduced membrane ruffles. Migration in response to wounding, cytokine-mediated chemotaxis, and transendothelial cell migration of cyclin D1-/- bone marrow-derived macrophages were all substantially reduced. Thus, apart from proliferative and possible motility defects in the tumor cells themselves, the reduced motility and invasiveness of cyclin D1-/- tumor-associated macrophages may contribute to the tumor resistance of these mice.
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Affiliation(s)
- Peter Neumeister
- Division of Hormone-dependent Tumor Biology, The Albert Einstein Comprehensive Cancer Center, Bronx, New York 10461, USA
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25
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Lieberman R. Evolving strategies for prostate cancer chemoprevention trials. World J Urol 2003; 21:3-8. [PMID: 12682772 DOI: 10.1007/s00345-003-0317-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2002] [Accepted: 12/15/2002] [Indexed: 10/25/2022] Open
Abstract
Prostate cancer chemoprevention (CP) can be defined as the use of natural and synthetic agents that inhibit, reverse or regress precancer and delay progression to invasive cancer. During the past two decades several CP strategies have evolved. The first generation of CP trials tested the efficacy of antioxidants and vitamins including B-carotene, vitamin A, retinol, 13 cis retinoic acid, vitamins E, C and selenium. Although these trials were disappointing, provocative hypotheses were generated for selenium and vitamin E that set the stage for future prostate trials. In the 1990s, the NCI launched a second generation of large CP trials aimed at breast and prostate cancer. One of these trials is the PCPT, testing the efficacy of a 5 alpha-reductase inhibitor-finasteride to prevent prostate cancer in 18,000 men. Although PCPT is still in progress, the NCI recently launched a second large primary prostate CP trial called SELECT, testing the efficacy of selenium and vitamin E in 32,400 men. The Prostate Cancer Progress Report to the Director of NCI in 1998 challenged the research community to design more efficient CP trials for prostate cancer. In response, the NCI has evolved a third generation of CP trials. This involves pharmacologically driven translational science research including agents and their targets, biomarker endpoints, suitable clinical models for testing agents and efficient trial designs employing high risk cohorts and surrogate endpoints. In summary, a dual strategy for CP is being developed which includes public health measures and a medical intervention approach.
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Affiliation(s)
- Ronald Lieberman
- Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd Room EPN 2102, Rockville MD 20852, USA.
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