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Le Y, Liu Q, Yang Y, Wu J. The emerging role of nuclear receptor coactivator 4 in health and disease: a novel bridge between iron metabolism and immunity. Cell Death Discov 2024; 10:312. [PMID: 38961066 PMCID: PMC11222541 DOI: 10.1038/s41420-024-02075-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/13/2024] [Accepted: 06/18/2024] [Indexed: 07/05/2024] Open
Abstract
Nuclear receptor coactivator 4 (NCOA4) has recently been recognized as a selective cargo receptor of ferritinophagy participating in ferroptosis. However, NCOA4 is also a coactivator that modulates the transcriptional activity of many vital nuclear receptors. Recent novel studies have documented the role of NCOA4 in healthy and pathogenic conditions via its modulation of iron- and non-iron-dependent metabolic pathways. NCOA4 exhibits non-ferritinophagic and iron-independent features such as promoting tumorigenesis and erythropoiesis, immunomodulation, regulating autophagy, and participating in DNA replication and mitosis. Full-length human-NCOA4 is composed of 614 amino acids, of which the N-terminal (1-237) contains nuclear-receptor-binding domains, while the C-terminal (238-614) principally contains a ferritin-binding domain. The exploration of the protein structure of NCOA4 suggests that NCOA4 possesses additional significant and complex functions based on its structural domains. Intriguingly, another three isoforms of NCOA4 that are produced by alternative splicing have been identified, which may also display disparate activities in physiological and pathological processes. Thus, NCOA4 has become an important bridge that encompasses interactions between immunity and metabolism. In this review, we outline the latest advances in the important regulating mechanisms underlying NCOA4 actions in health and disease conditions, providing insights into potential therapeutic interventions.
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Affiliation(s)
- Yue Le
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Qinjie Liu
- Department of General Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Yi Yang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, China.
| | - Jie Wu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, China.
- Research Center of Surgery, BenQ Medical Center, the Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210021, China.
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NCOA4 is regulated by HIF and mediates mobilization of murine hepatic iron stores after blood loss. Blood 2021; 136:2691-2702. [PMID: 32659785 DOI: 10.1182/blood.2020006321] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/27/2020] [Indexed: 12/17/2022] Open
Abstract
The mechanisms by which phlebotomy promotes the mobilization of hepatic iron stores are not well understood. NCOA4 (nuclear receptor coactivator 4) is a widely expressed intracellular protein previously shown to mediate the autophagic degradation of ferritin. Here, we investigate a local requirement for NCOA4 in the regulation of hepatic iron stores and examine mechanisms of NCOA4 regulation. Hepatocyte-targeted Ncoa4 knockdown in nonphlebotomized mice had only modest effects on hepatic ferritin subunit levels and nonheme iron concentration. After phlebotomy, mice with hepatocyte-targeted Ncoa4 knockdown exhibited anemia and hypoferremia similar to control mice with intact Ncoa4 regulation but showed a markedly impaired ability to lower hepatic ferritin subunit levels and hepatic nonheme iron concentration. This impaired hepatic response was observed even when dietary iron was limited. In both human and murine hepatoma cell lines, treatment with chemicals that stabilize hypoxia inducible factor (HIF), including desferrioxamine, cobalt chloride, and dimethyloxalylglycine, raised NCOA4 messenger RNA. This NCOA4 messenger RNA induction occurred within 3 hours, preceded a rise in NCOA4 protein, and was attenuated in the setting of dual HIF-1α and HIF-2α knockdown. In summary, we show for the first time that NCOA4 plays a local role in facilitating iron mobilization from the liver after blood loss and that HIF regulates NCOA4 expression in cells of hepatic origin. Because the prolyl hydroxylases that regulate HIF stability are oxygen- and iron-dependent enzymes, our findings suggest a novel mechanism by which hypoxia and iron deficiency may modulate NCOA4 expression to impact iron homeostasis.
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Quiles Del Rey M, Mancias JD. NCOA4-Mediated Ferritinophagy: A Potential Link to Neurodegeneration. Front Neurosci 2019; 13:238. [PMID: 30930742 PMCID: PMC6427834 DOI: 10.3389/fnins.2019.00238] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 02/28/2019] [Indexed: 01/15/2023] Open
Abstract
NCOA4 (Nuclear receptor coactivator 4) mediates the selective autophagic degradation of ferritin, the cellular cytosolic iron storage complex, thereby playing a critical role in intracellular and systemic iron homeostasis. Disruptions in iron homeostasis and autophagy are observed in several neurodegenerative disorders raising the possibility that NCOA4-mediated ferritinophagy links these two observations and may underlie, in part, the pathophysiology of neurodegeneration. Here, we review the available evidence detailing the molecular mechanisms of NCOA4-mediated ferritinophagy and recent studies examining its role in systemic iron homeostasis and erythropoiesis. We propose additional studies to examine the potential role of NCOA4 in the brain in the context of neurodegenerative diseases.
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Affiliation(s)
- Maria Quiles Del Rey
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
| | - Joseph D Mancias
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
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4
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Santana-Codina N, Mancias JD. The Role of NCOA4-Mediated Ferritinophagy in Health and Disease. Pharmaceuticals (Basel) 2018; 11:E114. [PMID: 30360520 PMCID: PMC6316710 DOI: 10.3390/ph11040114] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Nuclear receptor coactivator 4 (NCOA4) is a selective cargo receptor that mediates the autophagic degradation of ferritin ("ferritinophagy"), the cytosolic iron storage complex. NCOA4-mediated ferritinophagy maintains intracellular iron homeostasis by facilitating ferritin iron storage or release according to demand. Ferritinophagy is involved in iron-dependent physiological processes such as erythropoiesis, where NCOA4 mediates ferritin iron release for mitochondrial heme synthesis. Recently, ferritinophagy has been shown to regulate ferroptosis, a newly described form of iron-dependent cell death mediated by excess lipid peroxidation. Dysregulation of iron metabolism and ferroptosis have been described in neurodegeneration, cancer, and infection, but little is known about the role of ferritinophagy in the pathogenesis of these diseases. Here, we will review the biochemical regulation of NCOA4, its contribution to physiological processes and its role in disease. Finally, we will discuss the potential of activating or inhibiting ferritinophagy and ferroptosis for therapeutic purposes.
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Affiliation(s)
- Naiara Santana-Codina
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
| | - Joseph D Mancias
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
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Rockfield S, Raffel J, Mehta R, Rehman N, Nanjundan M. Iron overload and altered iron metabolism in ovarian cancer. Biol Chem 2017; 398:995-1007. [PMID: 28095368 DOI: 10.1515/hsz-2016-0336] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 01/09/2017] [Indexed: 12/28/2022]
Abstract
Iron is an essential element required for many processes within the cell. Dysregulation in iron homeostasis due to iron overload is detrimental. This nutrient is postulated to contribute to the initiation of cancer; however, the mechanisms by which this occurs remain unclear. Defining how iron promotes the development of ovarian cancers from precursor lesions is essential for developing novel therapeutic strategies. In this review, we discuss (1) how iron overload conditions may initiate ovarian cancer development, (2) dysregulated iron metabolism in cancers, (3) the interplay between bacteria, iron, and cancer, and (4) chemotherapeutic strategies targeting iron metabolism in cancer patients.
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Genome-wide coexpression of steroid receptors in the mouse brain: Identifying signaling pathways and functionally coordinated regions. Proc Natl Acad Sci U S A 2016; 113:2738-43. [PMID: 26811448 DOI: 10.1073/pnas.1520376113] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Steroid receptors are pleiotropic transcription factors that coordinate adaptation to different physiological states. An important target organ is the brain, but even though their effects are well studied in specific regions, brain-wide steroid receptor targets and mediators remain largely unknown due to the complexity of the brain. Here, we tested the idea that novel aspects of steroid action can be identified through spatial correlation of steroid receptors with genome-wide mRNA expression across different regions in the mouse brain. First, we observed significant coexpression of six nuclear receptors (NRs) [androgen receptor (Ar), estrogen receptor alpha (Esr1), estrogen receptor beta (Esr2), glucocorticoid receptor (Gr), mineralocorticoid receptor (Mr), and progesterone receptor (Pgr)] with sets of steroid target genes that were identified in single brain regions. These coexpression relationships were also present in distinct other brain regions, suggestive of as yet unidentified coordinate regulation of brain regions by, for example, glucocorticoids and estrogens. Second, coexpression of a set of 62 known NR coregulators and the six steroid receptors in 12 nonoverlapping mouse brain regions revealed selective downstream pathways, such as Pak6 as a mediator for the effects of Ar and Gr on dopaminergic transmission. Third, Magel2 and Irs4 were identified and validated as strongly responsive targets to the estrogen diethylstilbestrol in the mouse hypothalamus. The brain- and genome-wide correlations of mRNA expression levels of six steroid receptors that we provide constitute a rich resource for further predictions and understanding of brain modulation by steroid hormones.
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Biasiotto G, Di Lorenzo D, Archetti S, Zanella I. Iron and Neurodegeneration: Is Ferritinophagy the Link? Mol Neurobiol 2015; 53:5542-74. [PMID: 26468157 DOI: 10.1007/s12035-015-9473-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/01/2015] [Indexed: 12/12/2022]
Abstract
Mounting evidence indicates that the lysosome-autophagy pathway plays a critical role in iron release from ferritin, the main iron storage cellular protein, hence in the distribution of iron to the cells. The recent identification of nuclear receptor co-activator 4 as the receptor for ferritin delivery to selective autophagy sheds further light on the understanding of the mechanisms underlying this pathway. The emerging view is that iron release from ferritin through the lysosomes is a general mechanism in normal and tumour cells of different tissue origins, but it has not yet been investigated in brain cells. Defects in the lysosome-autophagy pathway are often involved in the pathogenesis of neurodegenerative disorders, and brain iron homeostasis disruption is a hallmark of many of these diseases. However, in most cases, it has not been established whether iron dysregulation is directly involved in the pathogenesis of the diseases or if it is a secondary effect derived from other pathogenic mechanisms. The recent evidence of the crucial involvement of autophagy in cellular iron handling offers new perspectives about the role of iron in neurodegeneration, suggesting that autophagy dysregulation could cause iron dyshomeostasis. In this review, we recapitulate our current knowledge on the routes through which iron is released from ferritin, focusing on the most recent advances. We summarise the current evidence concerning lysosome-autophagy pathway dysfunctions and those of iron metabolism and discuss their potential interconnections in several neurodegenerative disorders, such as Alzheimer's, Parkinson's and Huntington's diseases; amyotrophic lateral sclerosis; and frontotemporal lobar dementia.
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Affiliation(s)
- Giorgio Biasiotto
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Diego Di Lorenzo
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Silvana Archetti
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Isabella Zanella
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy.
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8
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Mancias JD, Pontano Vaites L, Nissim S, Biancur DE, Kim AJ, Wang X, Liu Y, Goessling W, Kimmelman AC, Harper JW. Ferritinophagy via NCOA4 is required for erythropoiesis and is regulated by iron dependent HERC2-mediated proteolysis. eLife 2015; 4. [PMID: 26436293 PMCID: PMC4592949 DOI: 10.7554/elife.10308] [Citation(s) in RCA: 311] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/05/2015] [Indexed: 12/27/2022] Open
Abstract
NCOA4 is a selective cargo receptor for the autophagic turnover of ferritin, a process critical for regulation of intracellular iron bioavailability. However, how ferritinophagy flux is controlled and the roles of NCOA4 in iron-dependent processes are poorly understood. Through analysis of the NCOA4-FTH1 interaction, we demonstrate that direct association via a key surface arginine in FTH1 and a C-terminal element in NCOA4 is required for delivery of ferritin to the lysosome via autophagosomes. Moreover, NCOA4 abundance is under dual control via autophagy and the ubiquitin proteasome system. Ubiquitin-dependent NCOA4 turnover is promoted by excess iron and involves an iron-dependent interaction between NCOA4 and the HERC2 ubiquitin ligase. In zebrafish and cultured cells, NCOA4 plays an essential role in erythroid differentiation. This work reveals the molecular nature of the NCOA4-ferritin complex and explains how intracellular iron levels modulate NCOA4-mediated ferritinophagy in cells and in an iron-dependent physiological setting. DOI:http://dx.doi.org/10.7554/eLife.10308.001 The cells of nearly all organisms need iron as this metal plays an important role in a wide range of biological processes. However, iron can also trigger the formation of harmful molecules that can damage cells. It is therefore crucial that the amount of iron in cells is tightly controlled and that any extra iron is safely stored away. Most of the iron in the body is stored within a protein called ferritin, which is then broken down to release iron as it is needed, in a process known as ferritinophagy. Cells use several systems to break down proteins, one of which, called autophagy, has been linked to ferritinophagy. During autophagy, a bubble-like structure called an autophagosome engulfs proteins that need to be removed and delivers them to a compartment in the cell where they can be broken down. In 2014, researchers showed that a protein called NCOA4 on the surface of autophagosomes targets ferritin for destruction. When iron levels are high in the cell, the amount of NCOA4 on the autophagosomes is low. This leads to fewer ferritin molecules being broken down. In contrast, low iron levels lead to an increase of NCOA4 on autophagosomes, which promotes ferritinophagy and increases the amount of iron in the cell. Now, Mancias, Vaites et al—including several of the researchers involved in the 2014 work—investigate the role of NCOA4 in ferritinophagy in more detail. Biochemical experiments revealed that a region of NCOA4 directly interacts with a particular subunit of ferritin and this interaction is necessary to deliver ferritin to autophagosomes. Mancias, Vaites et al. then used laboratory grown-cells to investigate why the amount of NCOA4 changes in response to the amount of iron in the cell. The experiments show the amount of NCOA4 varies depending on whether it interacts with another protein called HERC2, which targets proteins for destruction by a structure called the proteasome. HERC2 only binds to NCOA4 when iron levels are high, which leads to NCOA4 being broken down by the proteasome. When iron levels are low, HERC2 does not interact with NCOA4. The presence of more NCOA4 then leads to more ferritinophagy, and so increases the amount of iron in the cell. Mancias, Vaites et al. also found that red blood cells, which depend highly on iron, do not develop properly in zebrafish that have lower amounts of the NCOA4 protein. Further work is needed to see whether NCOA4 is also important for the development of other cells and tissues. DOI:http://dx.doi.org/10.7554/eLife.10308.002
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Affiliation(s)
- Joseph D Mancias
- Department of Cell Biology, Harvard Medical School, Boston, United States.,Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States.,Department of Radiation Oncology, Harvard Medical School, Boston, United States
| | | | - Sahar Nissim
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States.,Genetics Division, Brigham and Women's Hospital, Boston, United States.,Dana-Farber Cancer Institute, Boston, United States
| | - Douglas E Biancur
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Andrew J Kim
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Xiaoxu Wang
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Yu Liu
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Wolfram Goessling
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States.,Genetics Division, Brigham and Women's Hospital, Boston, United States.,Dana-Farber Cancer Institute, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Alec C Kimmelman
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, United States
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Van Tilborgh N, Spans L, Helsen C, Clinckemalie L, Dubois V, Lerut E, Boonen S, Vanderschueren D, Claessens F. The transcription intermediary factor 1β coactivates the androgen receptor. J Endocrinol Invest 2013; 36:699-706. [PMID: 23563173 DOI: 10.3275/8927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The androgen receptor (AR) is a ligand-inducible transcription factor. Its transcription activation domain consists of the two transcription activation units called Tau-1 and Tau- 5. Tau-5 interacts with p160 coactivators like the transcription intermediary factor 2 (TIF2), which in their turn recruit histone modifiers and chromatin-remodelling complexes. The mechanism of action of Tau-1, however, remains elusive. Here, we demonstrate that transcription intermediary factor 1β (TIF1β) can induce the activity of the AR up to five fold when tested in vitro. Although there is no evidence for direct interactions between TIF1β and AR, mutation studies show that the activity of TIF1β depends on the integrity of Tau-1 in AR on the one hand, and the so-called tripartite motif domain in TIF1β on the other. Surprisingly, the coactivation by TIF1β via Tau-1 seems additive rather than cooperative with the AR coactivation by TIF2. Some mutations naturally occurring in androgen-insensitivity syndrome patients that reside in Tau-1 seem to impair the TIF1β coactivation of the AR, indicating that TIF1β could also be relevant for the in vivo androgen response in humans. Moreover, since TIF1β is well expressed in prostate cancer cells, its functional interaction with androgen signalling could in the long run be a therapeutic target for this disease.
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Affiliation(s)
- N Van Tilborgh
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg, Leuven, Belgium
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FitzGerald LM, Zhang X, Kolb S, Kwon EM, Liew YC, Hurtado-Coll A, Knudsen BS, Ostrander EA, Stanford JL. Investigation of the relationship between prostate cancer and MSMB and NCOA4 genetic variants and protein expression. Hum Mutat 2012; 34:149-56. [PMID: 22887727 DOI: 10.1002/humu.22176] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Accepted: 07/19/2012] [Indexed: 12/21/2022]
Abstract
Two genome-wide association studies (GWAS) identified the β-microseminoprotein (MSMB) promoter SNP, rs10993994:C>T, as significantly associated with prostate cancer (PC) risk. Follow-up studies demonstrate that the variant allele directly affects expression of the MSMB-encoded protein, PSP94, and also suggest that it affects mRNA expression levels of an adjacent gene, NCOA4, which is involved in androgen receptor transactivation. In a population-based study of 1,323 cases and 1,268 age-matched controls, we found the NCOA4 SNP, rs7350420:T>C, was associated with a 15% reduction in PC risk, but the association was not significant after adjustment for the rs10993994:C>T genotype. Tumor tissue microarrays of 519 radical prostatectomy patients were used to measure PSP94 and NCOA4 protein expression. Taken together, these data confirm that the rs10993994:C>T variant allele is associated with decreased PSP94 expression, and the association is stronger in tumor compared to normal prostate tissue. No association was observed between rs10993994:C>T and NCOA4 expression, and only moderate associations were seen between two NCOA4 SNPs, rs10761618:T>C and rs7085433:G>A, and NCOA4 protein expression. These data indicate that the increase in PC risk associated with rs10993994:C>T is likely mediated by the variant's effect on PSP94 expression; however, this effect does not extend to NCOA4 in the data presented here.
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Affiliation(s)
- Liesel M FitzGerald
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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11
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Lou H, Li H, Yeager M, Im K, Gold B, Schneider TD, Fraumeni JF, Chanock SJ, Anderson SK, Dean M. Promoter variants in the MSMB gene associated with prostate cancer regulate MSMB/NCOA4 fusion transcripts. Hum Genet 2012; 131:1453-1466. [PMID: 22661295 PMCID: PMC3956317 DOI: 10.1007/s00439-012-1182-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 05/11/2012] [Indexed: 12/22/2022]
Abstract
Beta-microseminoprotein (MSP)/MSMB is an immunoglobulin superfamily protein synthesized by prostate epithelial cells and secreted into seminal plasma. Variants in the promoter of the MSMB gene have been associated with the risk of prostate cancer (PCa) in several independent genome-wide association studies. Both MSMB and an adjacent gene, NCOA4, are subjected to transcriptional control via androgen response elements. The gene product of NCOA4 interacts directly with the androgen receptor as a co-activator to enhance AR transcriptional activity. Here, we provide evidence for the expression of full-length MSMB-NCOA4 fusion transcripts regulated by the MSMB promoter. The predominant MSMB-NCOA4 transcript arises by fusion of the 5'UTR and exons 1-2 of the MSMB pre-mRNA, with exons 2-10 of the NCOA4 pre-mRNA, producing a stable fusion protein, comprising the essential domains of NCOA4. Analysis of the splice sites of this transcript shows an unusually strong splice acceptor at NCOA4 exon 2 and the presence of Alu repeats flanking the exons potentially involved in the splicing event. Transfection experiments using deletion clones of the promoter coupled with luciferase reporter assays define a core MSMB promoter element located between -27 and -236 of the gene, and a negative regulatory element immediately upstream of the start codon. Computational network analysis reveals that the MSMB gene is functionally connected to NCOA4 and the androgen receptor signaling pathway. The data provide an example of how GWAS-associated variants may have multiple genetic and epigenetic effects.
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Affiliation(s)
- Hong Lou
- Human Genetics Section, Basic Research Program, SAIC-Frederick Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Hongchuan Li
- Molecular Immunology Section, Basic Research Program, SAIC-Frederick Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Meredith Yeager
- Core Genotyping Facility, Advanced Technology Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Kate Im
- Cancer and Inflammation Program, Laboratory of Experimental Immunology, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Bert Gold
- Cancer and Inflammation Program, Laboratory of Experimental Immunology, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Thomas D Schneider
- Gene Regulation and Chromosome Biology Laboratory, Molecular Information Theory Group, Frederick, MD 21702, USA
| | - Joseph F Fraumeni
- Division of Cancer Epidemiology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Stephen J Chanock
- Division of Cancer Epidemiology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Stephen K Anderson
- Molecular Immunology Section, Basic Research Program, SAIC-Frederick Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Michael Dean
- Cancer and Inflammation Program, Laboratory of Experimental Immunology, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702, USA
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Ligr M, Li Y, Logan SK, Taneja S, Melamed J, Lepor H, Garabedian MJ, Lee P. Mifepristone inhibits GRβ coupled prostate cancer cell proliferation. J Urol 2012; 188:981-8. [PMID: 22819113 DOI: 10.1016/j.juro.2012.04.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Indexed: 10/28/2022]
Abstract
PURPOSE The GR gene produces GRα and GRβ isoforms by alternative splicing of a C-terminal exon. GRα binds glucocorticoids, modulates transcription in a glucocorticoid dependent manner and has a growth inhibitory role in prostate cells. Due to this role glucocorticoids are often used to treat androgen independent prostate cancer. In contrast, GRβ has intrinsic transcriptional activity and binds mifepristone (RU486) but not glucocorticoids to control gene expression. To our knowledge the role of GRβ in prostate cell proliferation is unknown. MATERIALS AND METHODS We determined GRβ levels in various prostate cancer cell lines by reverse transcriptase-polymerase chain reaction and Western blot. The effect of GRβ on the kinetics of prostate cancer cell growth was determined by cell counting and flow cytometry upon mifepristone and dexamethasone treatment. Cell proliferation was also examined after siRNA mediated knockdown and over expression of GRβ. RESULTS GRβ mRNA and protein were up-regulated in LNCaP cells that over expressed the androgen receptor co-factor ARA70β. Treatment of LNCaP-ARA70β with mifepristone or siRNA targeting GRβ inhibited proliferation compared to that of parental LNCaP cells. The immortal but nontumorigenic RC165 prostate cell line and the tumorigenic DU145 prostate cell line with endogenous GRβ also showed partial growth reduction upon GRβ depletion but to a lesser extent than LNCaP-ARA70β cells. The growth stimulatory effect of ARA70β on LNCaP cells was partly GRβ dependent, as was the proliferation of RC165 cells and to a lesser extent of DU145 cells. CONCLUSIONS Results suggest that patients with a primary tumor that expresses GRβ and ARA70β may benefit from mifepristone.
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Affiliation(s)
- Martin Ligr
- Department of Pathology, New York University School of Medicine, New York, New York 10010, USA
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13
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Kollara A, Brown TJ. Expression and function of nuclear receptor co-activator 4: evidence of a potential role independent of co-activator activity. Cell Mol Life Sci 2012; 69:3895-909. [PMID: 22562579 PMCID: PMC3492700 DOI: 10.1007/s00018-012-1000-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 04/13/2012] [Accepted: 04/17/2012] [Indexed: 12/22/2022]
Abstract
Nuclear receptor coactivator 4 (NcoA4), also known as androgen receptor-associated protein 70 (ARA70), was initially discovered as a component of Ret-Fused Gene expressed in a subset of papillary thyroid carcinomas. Subsequent studies have established NcoA4 as a coactivator for a variety of nuclear receptors, including peroxisome proliferator activated receptors α and γ, and receptors for steroid hormones, vitamins D and A, thyroid hormone, and aryl hydrocarbons. While human NcoA4 has both LXXLL and FXXLF motifs that mediate p160 coactivator nuclear receptor interactions, this ubiquitously expressed protein lacks clearly defined functional domains. Several studies indicate that NcoA4 localizes predominantly to the cytoplasm and affects ligand-binding specificity of the androgen receptor, which has important implications for androgen-independent prostate cancer. Two NcoA4 variants, which may exert differential activities, have been identified in humans. Recent studies suggest that NcoA4 may play a role in development, carcinogenesis, inflammation, erythrogenesis, and cell cycle progression that may be independent of its role as a receptor coactivator. This review summarizes what is currently known of the structure, expression, regulation, and potential functions of this unique protein in cancerous and non-cancerous pathologies.
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Affiliation(s)
- Alexandra Kollara
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 25 Orde Street, 6-1001TB, Toronto, ON, M5T 3H7, Canada
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14
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Chen C, Sibley E. Expression profiling identifies novel gene targets and functions for Pdx1 in the duodenum of mature mice. Am J Physiol Gastrointest Liver Physiol 2012; 302:G407-19. [PMID: 22135308 PMCID: PMC3287393 DOI: 10.1152/ajpgi.00314.2011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 11/28/2011] [Indexed: 01/31/2023]
Abstract
Transcription factor pancreatic and duodenal homeobox 1 (Pdx1) plays an essential role in the pancreas to regulate its development and maintain proper islet function. However, the functions of Pdx1 in mature small intestine are less known. We aimed to investigate the intestinal role of Pdx1 by profiling the expression of genes differentially regulated in response to inactivation of Pdx1 specifically in the intestinal epithelium. Pdx1 was conditionally inactivated in the intestinal epithelium of Pdx1(flox/flox);VilCre mice. Total RNA was isolated from the first 5 cm of the small intestine from mature Pdx1(flox/flox);VilCre and littermate control mice. Microarray analysis identified 86 probe sets representing 68 genes significantly upregulated or downregulated 1.5-fold or greater in Pdx(flox/flox);VilCre mice maintained under standard conditions. Ingenuity Pathway Analysis revealed that functions of the differentially expressed genes are significantly associated with metabolism of nutrients including lipids and iron. Network analysis examining the interactions among the differentially expressed genes further supports the notion that Pdx1 may modulate metabolism of lipids and iron from mature intestinal epithelium. Following forced oil feeding, Pdx1(flox/flox);VilCre mice showed diminished lipid staining in the duodenal epithelium and decreased serum triglyceride levels, indicating reduced lipid absorption compared with control duodenal epithelium. Blood samples from Pdx1(flox/flox);VilCre mice have significantly lower mean values for mean corpuscular volume and mean corpuscular hemoglobin, consistent with iron deficiency. The absence of nonheme iron in the villous epithelium and lamina propria of Pdx1(flox/flox);VilCre duodenum indicates that the duodenal epithelium lacking Pdx1 may have defects in importing iron through enterocytes, resulting in iron deficiency in Pdx1(flox/flox);VilCre mice.
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Affiliation(s)
- Chin Chen
- Dept. of Pediatrics, Stanford Univ. School of Medicine, Stanford, CA 94305-5208, USA.
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15
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Kollara A, Brown TJ. Variable expression of nuclear receptor coactivator 4 (NcoA4) during mouse embryonic development. J Histochem Cytochem 2010; 58:595-609. [PMID: 20354146 DOI: 10.1369/jhc.2010.955294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human nuclear receptor coactivator 4 (NcoA4) amplifies the activity of several ligand-activated nuclear transcription factors, including the aryl hydrocarbon receptor (AhR) and androgen receptor (AR). Because these receptors exert important regulatory effects during development, with AhR ubiquitously expressed after embryonic day 9.5 (E9.5) and AR expressed from E12 onward, we examined NcoA4 expression in mouse embryos from E9.5 to E17.5. Full-length NcoA4 transcript was detected by RT-PCR at all embryonic stages and in all adult mouse tissues examined, although a novel splice variant was also detected. Western blot analysis indicated the expression of full-length NcoA4 protein, which was more highly expressed at later (E15.5-E17.5) embryonic stages. NcoA4 protein was also present at varying levels in all adult mouse tissues examined. A dynamic expression profile for NcoA4 during early development was indicated by immunohistochemistry in cardiac, hepatic, and lung tissue. Unlike human NcoA4, murine NcoA4 lacks an LXXLL motif, which has been implicated in the interaction with AR. Overexpression of murine NcoA4 augmented the transcriptional activity of AhR by 5-fold and AR by only 1.5-fold in COS cells. These studies demonstrate ubiquitous NcoA4 expression throughout development and suggest that this coactivator may play a role in modulating nuclear receptor activity, particularly that of the AhR, during development.
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Affiliation(s)
- Alexandra Kollara
- Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, ON, Canada
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16
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Ligr M, Li Y, Zou X, Daniels G, Melamed J, Peng Y, Wang W, Wang J, Ostrer H, Pagano M, Wang Z, Garabedian MJ, Lee P. Tumor suppressor function of androgen receptor coactivator ARA70alpha in prostate cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1891-900. [PMID: 20167864 DOI: 10.2353/ajpath.2010.090293] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Androgen receptor (AR), a member of the steroid receptor family, is a transcription factor that has an important role in the regulation of both prostate cell proliferation and growth suppression. AR coactivators may influence the transition between cell growth and growth suppression. We have shown previously that the internally spliced ARA70 isoform, ARA70beta, promotes prostate cancer cell growth and invasion. Here we report that the full length ARA70alpha, in contrast, represses prostate cancer cell proliferation and anchorage-independent growth in vitro and inhibits tumor growth in nude mice xenograft experiments in vivo. Further, the growth inhibition by ARA70alpha is AR-dependent and mediated through induction of apoptosis rather than cell cycle arrest. Interestingly, AR with T877A mutation in LNCaP cells decreased its physical and functional interaction with ARA70alpha, facilitating the growth of LNCaP cells. The tumor suppressor function of ARA70alpha is consistent with our previous findings that ARA70alpha expression is decreased in prostate cancer cells compared with benign prostate. ARA70alpha also reduced the invasion ability of LNCaP cells. Although growth inhibition by ARA70alpha is AR-dependent, the inhibition of cell invasion is an androgen-independent process. These results strongly suggest that ARA70alpha functions as a tumor suppressor gene.
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Affiliation(s)
- Martin Ligr
- Department of Pathology and Urology, New York University School of Medicine, New York Harbor Healthcare System, New York, NY 10010, USA
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17
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Beischlag TV, Luis Morales J, Hollingshead BD, Perdew GH. The aryl hydrocarbon receptor complex and the control of gene expression. Crit Rev Eukaryot Gene Expr 2008; 18:207-50. [PMID: 18540824 DOI: 10.1615/critreveukargeneexpr.v18.i3.20] [Citation(s) in RCA: 540] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that controls the expression of a diverse set of genes. The toxicity of the potent AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin is almost exclusively mediated through this receptor. However, the key alterations in gene expression that mediate toxicity are poorly understood. It has been established through characterization of AhR-null mice that the AhR has a required physiological function, yet how endogenous mediators regulate this orphan receptor remains to be established. A picture as to how the AhR/ARNT heterodimer actually mediates gene transcription is starting to emerge. The AhR/ARNT complex can alter transcription both by binding to its cognate response element and through tethering to other transcription factors. In addition, many of the coregulatory proteins necessary for AhR-mediated transcription have been identified. Cross talk between the estrogen receptor and the AhR at the promoter of target genes appears to be an important mode of regulation. Inflammatory signaling pathways and the AhR also appear to be another important site of cross talk at the level of transcription. A major focus of this review is to highlight experimental efforts to characterize nonclassical mechanisms of AhR-mediated modulation of gene transcription.
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Affiliation(s)
- Timothy V Beischlag
- Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
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18
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Peng Y, Li CX, Chen F, Wang Z, Ligr M, Melamed J, Wei J, Gerald W, Pagano M, Garabedian MJ, Lee P. Stimulation of prostate cancer cellular proliferation and invasion by the androgen receptor co-activator ARA70. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 172:225-35. [PMID: 18156210 DOI: 10.2353/ajpath.2008.070065] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
ARA70 was first identified as a gene fused to the ret oncogene in thyroid carcinoma and subsequently as a co-activator for androgen receptor (AR). Two isoforms of ARA70 have been identified: a 70-kDa version called ARA70 alpha and an internally spliced 35-kDa variant termed ARA70 beta. We have previously reported that ARA70 alpha expression is reduced in prostate cancer, and its overexpression inhibits proliferation of LNCaP prostate cancer cells. However, the function of the ARA70 beta isoform in prostate cancer is not understood. In this report we examined the effects of ARA70 beta on AR transcriptional regulation as well as prostate cancer cellular proliferation and invasion. Although both ARA70 alpha and ARA70 beta functioned as transcriptional co-activators of AR in cell-based reporter assays, ARA70 beta overexpression, in contrast to ARA70 alpha, promoted prostate cancer cellular proliferation and invasion through Matrigel. Interestingly, genome-wide expression profiling of cells expressing ARA70 beta revealed an increase in the expression of genes involved in the control of cell division and adhesion, compatible with a role for ARA70 beta in proliferation and invasion. Consistent with its function in promoting cell growth and invasion, ARA70 beta expression was increased in prostate cancer. Our findings implicate ARA70 beta as a regulator of tumor cell growth and metastasis by affecting gene expression.
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Affiliation(s)
- Yi Peng
- Department of Pathology, New York University School of Medicine, New York Harbor Healthcare System, 423 E. 23rd St., Room 6140N, New York, NY 10010, USA
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19
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Berndt K, Kim M, Meinhardt A, Klug J. Macrophage migration inhibitory factor does not modulate co-activation of androgen receptor by Jab1/CSN5. Mol Cell Biochem 2007; 307:265-71. [PMID: 17786542 DOI: 10.1007/s11010-007-9578-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 08/10/2007] [Indexed: 01/12/2023]
Abstract
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory immune modulator that plays an important role in the regulation of innate and adaptive immune responses. MIF signaling involves CD74/CD44 membrane receptor complexes, the chemokine receptors CXCR2 and 4 as well as uptake by non-receptor mediated endocytosis. Endocytosed or endogenous MIF interacts with Jun activation domain-binding protein 1 (Jab1), originally described as transcriptional co-activator for the transcription factor AP-1, that is also known as subunit 5 of the COP9 signalosome (CSN5). Since Jab1/CSN5 also functions as a co-activator for a number of steroid hormone receptors (SHRs), it had been speculated that MIF could modulate Jab1/CSN5-SHR interactions. Here we show (i) that fluorescently labeled MIF is internalized by NIH 3T3 cells within minutes, (ii) compromises the induction of phospho-c-Jun levels by TNFalpha and PMA and, hence, is biologically active, but (iii) is not able to interfere with co-activation by Jab1/CSN5 of the androgen receptor.
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Affiliation(s)
- Kersten Berndt
- Institut für Anatomie und Zellbiologie, Justus-Liebig-Universität Giessen, Aulweg 123, 35385, Giessen, Germany
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20
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Girling JS, Whitaker HC, Mills IG, Neal DE. Pathogenesis of prostate cancer and hormone refractory prostate cancer. Indian J Urol 2007; 23:35-42. [PMID: 19675761 PMCID: PMC2721494 DOI: 10.4103/0970-1591.30265] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Prostate cancer is the second most common malignancy in males and the leading cause of cancer death. Prostate cancer is initially androgen dependent and relies upon the androgen receptor (AR) to mediate the effects of androgens. The AR is also the target for therapy using antiandrogens and LHRH analogues. However, all cancers eventually become androgen independent, often referred to as hormone refractory prostate cancer. The processes involved in this transformation are yet to be fully understood but research in this area has discovered numerous potential mechanisms including AR amplification, over-expression or mutation and alterations in the AR signaling pathway. This review of the recent literature examines the current knowledge and developments in the understanding of the molecular biology of prostate cancer and hormone refractory prostate cancer, summarizing the well characterized pathways involved as well as introducing new concepts that may offer future solutions to this difficult problem.
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Affiliation(s)
- J. S. Girling
- CRUK Uro-oncolgy Group, Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, CB2 2XZ, UK
| | - H. C. Whitaker
- CRUK Uro-oncolgy Group, Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, CB2 2XZ, UK
| | - I. G. Mills
- CRUK Uro-oncolgy Group, Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, CB2 2XZ, UK
| | - D. E. Neal
- CRUK Uro-oncolgy Group, Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, CB2 2XZ, UK
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Rahman M, Miyamoto H, Chang C. Androgen receptor coregulators in prostate cancer: mechanisms and clinical implications. Clin Cancer Res 2004; 10:2208-19. [PMID: 15073094 DOI: 10.1158/1078-0432.ccr-0746-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mujib Rahman
- George Whipple Laboratory for Cancer Research, Department of Biochemistry, and the Cancer Center, University of Rochester Medical Center, Rochester, New York 14642, USA
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22
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Ding L, Yan J, Zhu J, Zhong H, Lu Q, Wang Z, Huang C, Ye Q. Ligand-independent activation of estrogen receptor alpha by XBP-1. Nucleic Acids Res 2003; 31:5266-74. [PMID: 12954762 PMCID: PMC203316 DOI: 10.1093/nar/gkg731] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The estrogen receptor (ER) is a member of a large superfamily of nuclear receptors that regulates the transcription of estrogen-responsive genes. Several recent studies have demonstrated that XBP-1 mRNA expression is associated with ERalpha status in breast tumors. However, the role of XBP-1 in ERalpha signaling remains to be elucidated. More recently, two forms of XBP-1 were identified due to its unconventional splicing. We refer to the spliced and unspliced forms of XBP-1 as XBP-1S and XBP-1U, respectively. Here, we report that XBP-1S and XBP-1U enhanced ERalpha-dependent transcriptional activity in a ligand-independent manner. XBP-1S had stronger activity than XBP-1U. The maximal effects of XBP-1S and XBP-1U on ERalpha transactivation were observed when they were co-expressed with full-length ERalpha. SRC-1, the p160 steroid receptor coactivator family member, synergized with XBP-1S or XBP-1U to potentiate ERalpha activity. XBP-1S and XBP-1U bound to the ERalpha both in vitro and in vivo in a ligand-independent fashion. XBP-1S and XBP-1U interacted with the ERalpha region containing the DNA-binding domain. The ERalpha-interacting regions on XBP-1S and XBP-1U have been mapped to two regions, including the N-terminal basic region leucine zipper domain (bZIP) and the C-terminal activation domain. The bZIP-deleted mutants of XBP-1S and XBP-1U completely abolished ERalpha transactivation by XBP-1S and XBP-1U. These findings suggest that XBP-1S and XBP-1U may directly modulate ERalpha signaling in both the absence and presence of estrogen and, therefore, may play important roles in the proliferation of normal and malignant estrogen-regulated tissues.
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Affiliation(s)
- Lihua Ding
- Beijing Institute of Biotechnology, Beijing 100850, Peoples Republic of China
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23
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Li X, Wong J, Tsai SY, Tsai MJ, O'Malley BW. Progesterone and glucocorticoid receptors recruit distinct coactivator complexes and promote distinct patterns of local chromatin modification. Mol Cell Biol 2003; 23:3763-73. [PMID: 12748280 PMCID: PMC155204 DOI: 10.1128/mcb.23.11.3763-3773.2003] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2003] [Revised: 02/05/2003] [Accepted: 03/12/2003] [Indexed: 12/21/2022] Open
Abstract
It is well established that steroid receptor function requires interaction with coactivators. However, the mechanisms through which steroid receptors elicit precise assembly of coactivator complexes and the way the steroid activation signal is transduced remain elusive. Using a T47D cell line stably integrated with a mouse mammary tumor virus-chloramphenicol acetyltransferase (MMTV-CAT) reporter, we demonstrate that specific steroid receptors exhibit preferential recruitment of SRC-1 family coactivators, which determines the subsequent recruitment of specific downstream coregulator molecules. Upon ligand treatment, progesterone receptor (PR) interacted preferentially with SRC-1, which recruited CBP and significantly enhanced acetylation at K5 of histone H4. In contrast, activated glucocorticoid receptor (GR) preferentially associated with SRC-2 (TIF-2/GRIP-1), which subsequently recruited pCAF and led to specific modification of histone H3, suggesting that specific coactivators recruit distinct histone acetyltransferases to modulate the transcription of steroid-responsive genes. Loss-of-function experiments further support the predicted roles of SRC-1 and SRC-2 in, respectively, PR- and GR-mediated transcription on the MMTV promoter. This study indicates that differential recruitment of coactivators by nuclear receptors determines the assembly of coactivator complexes on target promoters to mediate specific transcription signals.
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Affiliation(s)
- Xiaotao Li
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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24
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Gao X, Loggie BW, Nawaz Z. The roles of sex steroid receptor coregulators in cancer. Mol Cancer 2002; 1:7. [PMID: 12473178 PMCID: PMC149410 DOI: 10.1186/1476-4598-1-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2002] [Accepted: 11/14/2002] [Indexed: 11/10/2022] Open
Abstract
Sex steroid hormones, estrogen, progesterone and androgen, play pivotal roles in sex differentiation and development, and in reproductive functions and sexual behavior. Studies have shown that sex steroid hormones are the key regulators in the development and progression of endocrine-related cancers, especially the cancers of the reproductive tissues. The actions of estrogen, progesterone and androgen are mediated through their cognate intracellular receptor proteins, the estrogen receptors (ER), the progesterone receptors (PR) and the androgen receptor (AR), respectively. These receptors are members of the nuclear receptor (NR) superfamily, which function as transcription factors that regulate their target gene expression. Proper functioning of these steroid receptors maintains the normal responsiveness of the target tissues to the stimulations of the steroid hormones. This permits the normal development and function of reproductive tissues. It can be inferred that factors influencing the expression or function of steroid receptors will interfere with the normal development and function of the target tissues, and may induce pathological conditions, including cancers. In addition to the direct contact with the basal transcription machinery, nuclear receptors enhance or suppress transcription by recruiting an array of coactivators and corepressors, collectively named coregulators. Therefore, the mutation or aberrant expression of sex steroid receptor coregulators will affect the normal function of the sex steroid receptors and hence may participate in the development and progression of the cancers.
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Affiliation(s)
- Xiuhua Gao
- CUMC-Cancer Center, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Brian W Loggie
- CUMC-Cancer Center, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Zafar Nawaz
- CUMC-Cancer Center, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
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Li P, Yu X, Ge K, Melamed J, Roeder RG, Wang Z. Heterogeneous expression and functions of androgen receptor co-factors in primary prostate cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 161:1467-74. [PMID: 12368219 PMCID: PMC1867282 DOI: 10.1016/s0002-9440(10)64422-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The androgen receptor (AR), a ligand-activated transcription factor of the steroid receptor superfamily, plays an important role in normal prostate growth and in prostate cancer. The recent identification of various AR co-factors prompted us to evaluate their possible roles in prostate tumorigenesis. To this end, we analyzed the expression of AR and eight of its co-factors by quantitative in situ RNA hybridization in 43 primary prostate cancers with different degrees of differentiation. Our results revealed nearly constant expression of AR and heterogeneous expression of AR co-factors, with increased expression of PIAS1 and Ran/ARA24, decreased expression of ELE1/ARA70, and no change in TMF1/ARA160, ARA54, SRC1, or TRAP220. Interestingly, whereas TMF1/ARA160, ELE1/ARA70, ARA54, RAN/ARA24, and PIAS1 were preferentially expressed in epithelial cells, another co-factor, ARA55, was preferentially expressed in stromal cells. Although the changes in levels of these co-activators did not correlate with Gleason score, their occurrence in high-grade prostatic intraepithelial neoplasia, suggests their involvement in initiation (or an early stage) of cancer. In addition, human prostate tumor cell proliferation and colony formation were markedly reduced by ELE1/ATRA70. Together, these findings indicate that changes in levels of expression of AR co-factors may play important, yet different, roles in prostate tumorigenesis.
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Affiliation(s)
- Peng Li
- Department of Pathology, New York University Medical Center, New York, New York, USA
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26
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Gnanapragasam VJ, Leung HY, Pulimood AS, Neal DE, Robson CN. Expression of RAC 3, a steroid hormone receptor co-activator in prostate cancer. Br J Cancer 2001; 85:1928-36. [PMID: 11747336 PMCID: PMC2364015 DOI: 10.1054/bjoc.2001.2179] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
RAC 3, one of the p160 family of co-activators is known to enhance the transcriptional activity of a number of steroid receptors. As co-activators are also known to enhance androgen receptor (AR) activity, we investigated the role of RAC 3 in the context of prostate cancer. In prostate cancer cell lines, we found variable levels of the RAC 3 protein with highest expression seen in AR-positive LNCaP cells, moderate expression in AR-negative PC 3 cells and low-level expression in AR-negative DU 145 cells. Immuno-precipitation studies showed that endogenous RAC 3 interacted with the AR in vivo and transfection assays confirmed that RAC 3 enhanced AR transcriptional activity. In clinical prostate tissue, we found strong RAC 3 mRNA expression and immuno-histochemistry demonstrated that in benign tissue, the protein was expressed predominantly in luminal cells, while in primary malignant epithelium it was more homogeneously expressed. In a series of 37 patients, the levels of RAC 3 expression correlated significantly with tumour grade (P = 0.01) and stage of disease (P = 0.03) but not with serum PSA levels. In addition moderate or high RAC 3 expression was associated with poorer disease-specific survival (P = 0.03). We conclude that RAC 3 is an important co-activator of the AR in the prostate and may have an important role in the progression of prostate cancer.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Aged
- Aged, 80 and over
- Androgens
- Biomarkers, Tumor/blood
- Disease Progression
- Epithelial Cells/metabolism
- Gene Expression Regulation, Neoplastic
- Humans
- In Situ Hybridization
- Male
- Middle Aged
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Staging
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Nuclear Receptor Coactivator 3
- Prostate-Specific Antigen/blood
- Prostatic Hyperplasia/metabolism
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Receptors, Androgen/metabolism
- Trans-Activators/biosynthesis
- Trans-Activators/genetics
- Transcription Factors
- Transcription, Genetic
- Transfection
- Tumor Cells, Cultured/metabolism
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Affiliation(s)
- V J Gnanapragasam
- Prostate Research Group, School of Surgical Sciences, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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27
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Haelens A, Verrijdt G, Callewaert L, Peeters B, Rombauts W, Claessens F. Androgen-receptor-specific DNA binding to an element in the first exon of the human secretory component gene. Biochem J 2001; 353:611-20. [PMID: 11171058 PMCID: PMC1221607 DOI: 10.1042/0264-6021:3530611] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Androgens and glucocorticoids are steroid hormones, which exert their effects in vivo by binding and activating their cognate receptors. These intracellular receptors are transcription factors that can bind specific DNA sequences, called hormone response elements, located near the target genes. Although the androgen receptor (AR) and the glucocorticoid receptor (GR) bind the same consensus DNA sequence, androgen-specific responses can be achieved by non-conventional androgen response elements (AREs). Here we determine the specificity mechanism of such a selective element recently identified in the first exon of the human gene for secretory component (sc ARE). This sc ARE consists of two receptor-binding hexamers separated by three nucleotides. The DNA-binding domains of the AR and GR both bind the sc ARE, but, although the AR fragment dimerizes on the element, the GR fragment does not. Comparing the affinities of the DNA-binding domains for mutant forms of the sc ARE revealed that dimeric GR binding is actively excluded by the left hexamer and more precisely by the presence of a G residue at position -3, relative to the central spacer nucleotide. Inserting a G at this position changed a non-selective element into an androgen-selective one. We postulate that the AR recognizes the sc ARE as a direct repeat of two 5'-TGTTCT-3'-like core sequences instead of the classical inverted repeat. Direct repeat binding is not possible for the GR, thus explaining the selectivity of the sc ARE. This alternative dimerization by the AR on the sc ARE is also indicated by the DNA-binding characteristics of receptor fragments in which the dimerization interfaces were swapped. In addition, the flanking and spacer sequences seem to affect the functionality of the sc ARE.
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Affiliation(s)
- A Haelens
- Division of Biochemistry, Faculty of Medicine, Campus Gasthuisberg, University of Leuven, Herestraat 49, B-3000 Leuven, Belgium
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Corvi R, Berger N, Balczon R, Romeo G. RET/PCM-1: a novel fusion gene in papillary thyroid carcinoma. Oncogene 2000; 19:4236-42. [PMID: 10980597 DOI: 10.1038/sj.onc.1203772] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The RET proto-oncogene is often activated through somatic rearrangements in papillary thyroid carcinomas (PTCs). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion and RET/PTC2, which originates from a 10 : 17 translocation. We previously developed a dual-color FISH test to detect these RET rearrangements in interphase nuclei of thyroid lesions. This approach allowed us to detect a novel translocation involving the RET region, which was not detectable by RT - PCR with specific primers for known rearrangements. A combination of RT - PCR and RACE analyses finally led to the identification of the fusion gene, which involves the 5' portion of PCM-1, a gene coding for a centrosomal protein with distinct cell cycle distribution, and the RET tyrosine kinase (TK) domain. FISH analysis confirmed the chromosomal localization of PCM-1 on chromosome 8p21-22, a region commonly deleted in several tumors. Immunohistochemistry, using an antibody specific for the C-terminal portion of PCM-1 showed that the protein level is drastically decreased and its subcellular localization is altered in thyroid tumor tissue with respect to normal thyroid. However, heterozygosity is retained for seven microsatellite markers in the 8p21-22 region, suggesting that the non-rearranged PCM-1 allele is not lost and that the translocation is balanced. Oncogene (2000) 19, 4236 - 4242
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MESH Headings
- Adult
- Carcinoma, Papillary/genetics
- Carcinoma, Papillary/pathology
- Chromosome Mapping
- Chromosomes, Human, Pair 10/genetics
- Chromosomes, Human, Pair 10/ultrastructure
- Chromosomes, Human, Pair 8/genetics
- Chromosomes, Human, Pair 8/ultrastructure
- Female
- Humans
- In Situ Hybridization, Fluorescence
- Interphase
- Loss of Heterozygosity
- Microsatellite Repeats
- Molecular Sequence Data
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/immunology
- Proto-Oncogene Mas
- Reverse Transcriptase Polymerase Chain Reaction
- Thyroid Neoplasms/genetics
- Thyroid Neoplasms/pathology
- Translocation, Genetic
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Affiliation(s)
- R Corvi
- International Agency for Research on Cancer, 150 cours Albert Thomas, 69372 Lyon, France
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Edwards DP. The role of coactivators and corepressors in the biology and mechanism of action of steroid hormone receptors. J Mammary Gland Biol Neoplasia 2000; 5:307-24. [PMID: 14973393 DOI: 10.1023/a:1009503029176] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Steroid hormone receptors are members of a superfamily of ligand-dependent transcription factors. As such they have a DNA binding domain that recognizes specific target gene sequences along with separate transcriptional activation domains. What sets steroid hormone receptors (and other nuclear hormone receptors) apart from other families of sequence specific transcriptional activators is the presence of a ligand binding domain (LBD) that acts as a molecular switch to turn on transcriptional activity when a hormonal ligand induces a conformational change in the receptor. Upon binding hormone, steroid receptors recruit a novel coactivator protein complex with an essential role in receptor-mediated transcriptional activation. Coactivators function as adaptors in a signaling pathway that transmits transcriptional responses from the DNA bound receptor to the basal transcriptional machinery. Hormone agonists induce a conformational change in the carboxyl-terminal transcriptional activation domain, AF-2, that creates a new protein interaction site on the surface of the LBD that is recognized by LXXLL motifs in the p160 family of coactivators. In contrast, steroid antagonists such as the antiestrogen tamoxifen for the estrogen receptor induce an alternate conformation in AF-2 that occludes the coactivator binding site and recruits corepressors that can actively silence steroid responsive genes. Thus, the cellular availability of coactivators and corepressors is an important determinant in the biological response to both steroid hormone agonists and antagonists. This paper provides an update on the properties and mechanism of action of nuclear receptor coactivators, the nature of the coactivator-binding site, and the structural and mechanistic basis for ligand-dependent binding of coactivators to receptors.
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Affiliation(s)
- D P Edwards
- University of Colorado Health Sciences Center, Department of Pathology, Denver 80262, USA.
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Müller JM, Isele U, Metzger E, Rempel A, Moser M, Pscherer A, Breyer T, Holubarsch C, Buettner R, Schüle R. FHL2, a novel tissue-specific coactivator of the androgen receptor. EMBO J 2000; 19:359-69. [PMID: 10654935 PMCID: PMC305573 DOI: 10.1093/emboj/19.3.359] [Citation(s) in RCA: 258] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The control of target gene expression by nuclear receptors requires the recruitment of multiple cofactors. However, the exact mechanisms by which nuclear receptor-cofactor interactions result in tissue-specific gene regulation are unclear. Here we characterize a novel tissue-specific coactivator for the androgen receptor (AR), which is identical to a previously reported protein FHL2/DRAL with unknown function. In the adult, FHL2 is expressed in the myocardium of the heart and in the epithelial cells of the prostate, where it colocalizes with the AR in the nucleus. FHL2 contains a strong, autonomous transactivation function and binds specifically to the AR in vitro and in vivo. In an agonist- and AF-2-dependent manner FHL2 selectively increases the transcriptional activity of the AR, but not that of any other nuclear receptor. In addition, the transcription of the prostate-specific AR target gene probasin is coactivated by FHL2. Taken together, our data demonstrate that FHL2 is the first LIM-only coactivator of the AR with a unique tissue-specific expression pattern.
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Affiliation(s)
- J M Müller
- Universitäts-Frauenklinik, Abteilung Frauenheilkunde und Geburtshilfe I, Klinikum der Universität Freiburg, Breisacherstrasse 117, 79106 Freiburg, Germany
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31
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Bevan CL, Hoare S, Claessens F, Heery DM, Parker MG. The AF1 and AF2 domains of the androgen receptor interact with distinct regions of SRC1. Mol Cell Biol 1999; 19:8383-92. [PMID: 10567563 PMCID: PMC84931 DOI: 10.1128/mcb.19.12.8383] [Citation(s) in RCA: 300] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/1999] [Accepted: 09/14/1999] [Indexed: 11/20/2022] Open
Abstract
The androgen receptor is unusual among nuclear receptors in that most, if not all, of its activity is mediated via the constitutive activation function in the N terminus. Here we demonstrate that p160 coactivators such as SRC1 (steroid receptor coactivator 1) interact directly with the N terminus in a ligand-independent manner via a conserved glutamine-rich region between residues 1053 and 1123. Although SRC1 is capable of interacting with the ligand-binding domain by means of LXXLL motifs, this interaction is not essential since an SRC1 mutant with no functional LXXLL motifs retains its ability to potentiate androgen receptor activity. In contrast, mutants lacking the glutamine-rich region are inactive, indicating that this region is both necessary and sufficient for recruitment of SRC1 to the androgen receptor. This recruitment is in direct contrast to the recruitment of SRC1 to the estrogen receptor, which requires interaction with the ligand-binding domain.
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Affiliation(s)
- C L Bevan
- Molecular Endocrinology Laboratory, Imperial Cancer Research Fund, London WC2A 3PX, United Kingdom
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Alen P, Claessens F, Verhoeven G, Rombauts W, Peeters B. The androgen receptor amino-terminal domain plays a key role in p160 coactivator-stimulated gene transcription. Mol Cell Biol 1999; 19:6085-97. [PMID: 10454556 PMCID: PMC84524 DOI: 10.1128/mcb.19.9.6085] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/1999] [Accepted: 05/11/1999] [Indexed: 01/08/2023] Open
Abstract
Steroid receptors are conditional transcription factors that, upon binding to their response elements, regulate the expression of target genes via direct protein interactions with transcriptional coactivators. We have analyzed the functional interactions between the androgen receptor (AR) and 160-kDa nuclear receptor coactivators. Upon overexpression in mammalian cells, these coactivators enhance the transcriptional activity of both the amino-terminal domain (NTD) and the ligand-binding domain (LBD) of the AR. The coactivator activity for the LBD is strictly ligand-controlled and depends on the nature of the DNA-binding domain to which it is fused. We demonstrate that the NTD physically interacts with coactivators and with the LBD and that this interaction, like the functional interaction between the LBD and p160 coactivators, relies on the activation function 2 (AF2) core domain. The mutation of a highly conserved lysine residue in the predicted helix 3 of the LBD (K720A), however, blunts the functional interaction with coactivators but not with the NTD. Moreover, this mutation does not affect the transcriptional activity of the full-size AR. A mutation in the NTD of activation function AF1a (I182A/L183A), which dramatically impairs the activity of the AR, has no effect on the intrinsic transcriptional activity of the NTD but interferes with the cooperation between the NTD and the LBD. Finally, p160 proteins in which the three LXXLL motifs are mutated retain most of their coactivator activity for the full-size AR, although they are no longer functional for the isolated LBD. Together, these data suggest that in the native AR the efficient recruitment of coactivators requires a functional association of the NTD with the LBD and that the binding of coactivators occurs primarily through the NTD.
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Affiliation(s)
- P Alen
- Division of Biochemistry, Faculty of Medicine, University of Leuven, B-3000 Leuven, Belgium
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