1
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Nelczyk AT, Ma L, Gupta AD, Gamage HEV, McHenry MT, Henn MA, Kadiri M, Wang Y, Krawczynska N, Bendre S, He S, Shahoei SH, Madak-Erdogan Z, Hsiao SH, Saleh T, Carpenter V, Gewirtz DA, Spinella MJ, Nelson ER. The nuclear receptor TLX (NR2E1) inhibits growth and progression of triple- negative breast cancer. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166515. [PMID: 35932893 PMCID: PMC9983295 DOI: 10.1016/j.bbadis.2022.166515] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 12/14/2022]
Abstract
Development of targeted therapies will be a critical step towards reducing the mortality associated with triple-negative breast cancer (TNBC). To achieve this, we searched for targets that met three criteria: (1) pharmacologically targetable, (2) expressed in TNBC, and (3) expression is prognostic in TNBC patients. Since nuclear receptors have a well-defined ligand-binding domain and are thus highly amenable to small-molecule intervention, we focused on this class of protein. Our analysis identified TLX (NR2E1) as a candidate. Specifically, elevated tumoral TLX expression was associated with prolonged recurrence-free survival and overall survival for breast cancer patients with either estrogen receptor alpha (ERα)-negative or basal-like tumors. Using two TNBC cell lines, we found that stable overexpression of TLX impairs in vitro proliferation. RNA-Seq analysis revealed that TLX reduced the expression of genes implicated in epithelial-mesenchymal transition (EMT), a cellular program known to drive metastatic progression. Indeed, TLX overexpression significantly decreased cell migration and invasion, and robustly decreased the metastatic capacity of TNBC cells in murine models. We identify SERPINB2 as a likely mediator of these effects. Taken together, our work indicates that TLX impedes the progression of TNBC. Several ligands have been shown to regulate the transcriptional activity of TLX, providing a framework for the future development of this receptor for therapeutic intervention.
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Affiliation(s)
- Adam T. Nelczyk
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Liqian Ma
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Anasuya Das Gupta
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hashni Epa Vidana Gamage
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Michael T. McHenry
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Madeline A. Henn
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Mohammed Kadiri
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yu Wang
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Natalia Krawczynska
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Shruti Bendre
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sisi He
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sayyed Hamed Shahoei
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Zeynep Madak-Erdogan
- Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA,Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.,Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Shih-Hsuan Hsiao
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Tareq Saleh
- Department of Basic Medical Sciences, The Hashemite University, Zarqa, Jordan
| | - Valerie Carpenter
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, 23298, USA
| | - David A. Gewirtz
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, 23298, USA
| | - Michael J. Spinella
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA,Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, Anticancer Discovery from Pets to People Theme, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Erik R. Nelson
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA,Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.,Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.,University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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2
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Shafi O, Siddiqui G. Tracing the origins of glioblastoma by investigating the role of gliogenic and related neurogenic genes/signaling pathways in GBM development: a systematic review. World J Surg Oncol 2022; 20:146. [PMID: 35538578 PMCID: PMC9087910 DOI: 10.1186/s12957-022-02602-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/15/2022] [Indexed: 02/16/2023] Open
Abstract
Background Glioblastoma is one of the most aggressive tumors. The etiology and the factors determining its onset are not yet entirely known. This study investigates the origins of GBM, and for this purpose, it focuses primarily on developmental gliogenic processes. It also focuses on the impact of the related neurogenic developmental processes in glioblastoma oncogenesis. It also addresses why glial cells are at more risk of tumor development compared to neurons. Methods Databases including PubMed, MEDLINE, and Google Scholar were searched for published articles without any date restrictions, involving glioblastoma, gliogenesis, neurogenesis, stemness, neural stem cells, gliogenic signaling and pathways, neurogenic signaling and pathways, and astrocytogenic genes. Results The origin of GBM is dependent on dysregulation in multiple genes and pathways that accumulatively converge the cells towards oncogenesis. There are multiple layers of steps in glioblastoma oncogenesis including the failure of cell fate-specific genes to keep the cells differentiated in their specific cell types such as p300, BMP, HOPX, and NRSF/REST. There are genes and signaling pathways that are involved in differentiation and also contribute to GBM such as FGFR3, JAK-STAT, and hey1. The genes that contribute to differentiation processes but also contribute to stemness in GBM include notch, Sox9, Sox4, c-myc gene overrides p300, and then GFAP, leading to upregulation of nestin, SHH, NF-κB, and others. GBM mutations pathologically impact the cell circuitry such as the interaction between Sox2 and JAK-STAT pathway, resulting in GBM development and progression. Conclusion Glioblastoma originates when the gene expression of key gliogenic genes and signaling pathways become dysregulated. This study identifies key gliogenic genes having the ability to control oncogenesis in glioblastoma cells, including p300, BMP, PAX6, HOPX, NRSF/REST, LIF, and TGF beta. It also identifies key neurogenic genes having the ability to control oncogenesis including PAX6, neurogenins including Ngn1, NeuroD1, NeuroD4, Numb, NKX6-1 Ebf, Myt1, and ASCL1. This study also postulates how aging contributes to the onset of glioblastoma by dysregulating the gene expression of NF-κB, REST/NRSF, ERK, AKT, EGFR, and others.
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Affiliation(s)
- Ovais Shafi
- Sindh Medical College - Jinnah Sindh Medical University / Dow University of Health Sciences, Karachi, Pakistan.
| | - Ghazia Siddiqui
- Sindh Medical College - Jinnah Sindh Medical University / Dow University of Health Sciences, Karachi, Pakistan
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3
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Faudone G, Kilu W, Ni X, Chaikuad A, Sreeramulu S, Heitel P, Schwalbe H, Knapp S, Schubert-Zsilavecz M, Heering J, Merk D. The Transcriptional Repressor Orphan Nuclear Receptor TLX Is Responsive to Xanthines. ACS Pharmacol Transl Sci 2021; 4:1794-1807. [PMID: 34927011 PMCID: PMC8669710 DOI: 10.1021/acsptsci.1c00195] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Indexed: 11/28/2022]
Abstract
The orphan nuclear receptor tailless homologue (TLX) is expressed almost exclusively in neural stem cells acting as an essential factor for their survival and is hence considered as a promising drug target in neurodegeneration. However, few studies have characterized the roles of TLX due to the lack of ligands and limited functional understanding. Here, we identify xanthines including caffeine and istradefylline as TLX modulators that counteract the receptor's intrinsic repressor activity. Mutagenesis of residues lining a cavity within the TLX ligand binding domain altered the activity of these ligands, suggesting direct interactions with helix 5. Using xanthines as tool compounds, we observed a ligand-sensitive recruitment of the co-repressor silencing mediator for retinoid or thyroid-hormone receptors, TLX homodimerization, and heterodimerization with the retinoid X receptor. These protein-protein interactions evolve as factors that modulate the TLX function and suggest an unprecedented role of TLX in directly repressing other nuclear receptors.
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Affiliation(s)
- Giuseppe Faudone
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Whitney Kilu
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Xiaomin Ni
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
- Structural
Genomics Consortium, BMLS, Goethe University
Frankfurt, Max-von-Laue-Str. 15, D-60438 Frankfurt, Germany
| | - Apirat Chaikuad
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
- Structural
Genomics Consortium, BMLS, Goethe University
Frankfurt, Max-von-Laue-Str. 15, D-60438 Frankfurt, Germany
| | - Sridhar Sreeramulu
- Center
for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic
Chemistry and Chemical Biology, Goethe University
Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt, Germany
| | - Pascal Heitel
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Harald Schwalbe
- Center
for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic
Chemistry and Chemical Biology, Goethe University
Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt, Germany
| | - Stefan Knapp
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
- Structural
Genomics Consortium, BMLS, Goethe University
Frankfurt, Max-von-Laue-Str. 15, D-60438 Frankfurt, Germany
| | - Manfred Schubert-Zsilavecz
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Jan Heering
- Fraunhofer
Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Daniel Merk
- Institute
of Pharmaceutical Chemistry, Goethe University
Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
- Department
of Pharmacy, Ludwig-Maximilians-Universität
München, Butenandtstr.
5-13, D-81377 Munich, Germany
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4
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Nelson AT, Wang Y, Nelson ER. TLX, an Orphan Nuclear Receptor With Emerging Roles in Physiology and Disease. Endocrinology 2021; 162:6360449. [PMID: 34463725 PMCID: PMC8462384 DOI: 10.1210/endocr/bqab184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Indexed: 12/14/2022]
Abstract
TLX (NR2E1), an orphan member of the nuclear receptor superfamily, is a transcription factor that has been described to be generally repressive in nature. It has been implicated in several aspects of physiology and disease. TLX is best known for its ability to regulate the proliferation of neural stem cells and retinal progenitor cells. Dysregulation, overexpression, or loss of TLX expression has been characterized in numerous studies focused on a diverse range of pathological conditions, including abnormal brain development, psychiatric disorders, retinopathies, metabolic disease, and malignant neoplasm. Despite the lack of an identified endogenous ligand, several studies have described putative synthetic and natural TLX ligands, suggesting that this receptor may serve as a therapeutic target. Therefore, this article aims to briefly review what is known about TLX structure and function in normal physiology, and provide an overview of TLX in regard to pathological conditions. Particular emphasis is placed on TLX and cancer, and the potential utility of this receptor as a therapeutic target.
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Affiliation(s)
- Adam T Nelson
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yu Wang
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Erik R Nelson
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
- Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
- University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, Illinois 60612, USA
- Carl R. Woese Institute for Genomic Biology, Anticancer Discovery from Pets to People Theme, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
- Correspondence: Erik R. Nelson, PhD, Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 407 S Goodwin Ave (MC-114), Urbana, IL 61801, USA.
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5
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Parkitny L, Maletic-Savatic M. Glial PAMPering and DAMPening of Adult Hippocampal Neurogenesis. Brain Sci 2021; 11:1299. [PMID: 34679362 PMCID: PMC8533961 DOI: 10.3390/brainsci11101299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 12/24/2022] Open
Abstract
Adult neurogenesis represents a mature brain's capacity to integrate newly generated neurons into functional circuits. Impairment of neurogenesis contributes to the pathophysiology of various mood and cognitive disorders such as depression and Alzheimer's Disease. The hippocampal neurogenic niche hosts neural progenitors, glia, and vasculature, which all respond to intrinsic and environmental cues, helping determine their current state and ultimate fate. In this article we focus on the major immune communication pathways and mechanisms through which glial cells sense, interact with, and modulate the neurogenic niche. We pay particular attention to those related to the sensing of and response to innate immune danger signals. Receptors for danger signals were first discovered as a critical component of the innate immune system response to pathogens but are now also recognized to play a crucial role in modulating non-pathogenic sterile inflammation. In the neurogenic niche, viable, stressed, apoptotic, and dying cells can activate danger responses in neuroimmune cells, resulting in neuroprotection or neurotoxicity. Through these mechanisms glial cells can influence hippocampal stem cell fate, survival, neuronal maturation, and integration. Depending on the context, such responses may be appropriate and on-target, as in the case of learning-associated synaptic pruning, or excessive and off-target, as in neurodegenerative disorders.
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Affiliation(s)
- Luke Parkitny
- Baylor College of Medicine and Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA;
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6
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Majidi S, Ogilvie JM, Flaveny CA. Retinal Degeneration: Short-Term Options and Long-Term Vision for Future Therapy. MISSOURI MEDICINE 2021; 118:466-472. [PMID: 34658442 PMCID: PMC8504501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The leading cause blindness is the loss of retinal ganglion cells which connect the retina to the brain. Degenerative retinal diseases include retinal dystrophy, macular degeneration and diabetic retinopathy, which are currently incurable as the mammalian retina has no intrinsic regenerative capacity. By utilizing insight gained from retinal regeneration in simpler species we define an approach that may unlock regenerative programs in the mammalian retina that potentially facilitate the clinical restoration of retinal function.
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Affiliation(s)
- Shabnam Majidi
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Judith M Ogilvie
- Department of Biology; Saint Louis University School of Medicine, St. Louis, Missouri
| | - Colin A Flaveny
- Department of Biology; Saint Louis University School of Medicine, St. Louis, Missouri
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7
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Faudone G, Bischoff-Kont I, Rachor L, Willems S, Zhubi R, Kaiser A, Chaikuad A, Knapp S, Fürst R, Heering J, Merk D. Propranolol Activates the Orphan Nuclear Receptor TLX to Counteract Proliferation and Migration of Glioblastoma Cells. J Med Chem 2021; 64:8727-8738. [PMID: 34115934 DOI: 10.1021/acs.jmedchem.1c00733] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ligand-sensing transcription factor tailless homologue (TLX, NR2E1) is an essential regulator of neuronal stem cell homeostasis with appealing therapeutic potential in neurodegenerative diseases and central nervous system tumors. However, knowledge on TLX ligands is scarce, providing an obstacle to target validation and medicinal chemistry. To discover TLX ligands, we have profiled a drug fragment collection for TLX modulation and identified several structurally diverse agonists and inverse agonists of the nuclear receptor. Propranolol evolved as the strongest TLX agonist and promoted TLX-regulated gene expression in human glioblastoma cells. Structure-activity relationship elucidation of propranolol as a TLX ligand yielded a structurally related negative control compound. In functional cellular experiments, we observed an ability of propranolol to counteract glioblastoma cell proliferation and migration, while the negative control had no effect. Our results provide a collection of TLX modulators as initial chemical tools and set of lead compounds and support therapeutic potential of TLX modulation in glioblastoma.
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Affiliation(s)
- Giuseppe Faudone
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Iris Bischoff-Kont
- Institute of Pharmaceutical Biology, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Lea Rachor
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Sabine Willems
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Rezart Zhubi
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.,Structural Genomics Consortium, BMLS, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt, Germany
| | - Astrid Kaiser
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Apirat Chaikuad
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.,Structural Genomics Consortium, BMLS, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt, Germany
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.,Structural Genomics Consortium, BMLS, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt, Germany
| | - Robert Fürst
- Institute of Pharmaceutical Biology, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Jan Heering
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt, Germany
| | - Daniel Merk
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
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8
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Zhou J, Pei X, Yang Y, Wang Z, Gao W, Ye R, Zhang X, Liu J, Liu Z, Yang X, Tao J, Gu C, Hu W, Chan FL, Li X, Mao J, Wu D. Orphan nuclear receptor TLX promotes immunosuppression via its transcriptional activation of PD-L1 in glioma. J Immunother Cancer 2021; 9:e001937. [PMID: 33858847 PMCID: PMC8055120 DOI: 10.1136/jitc-2020-001937] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND High-grade gliomas are rapidly progressing tumors of the central nervous system, and are associated with poor prognosis and highly immunosuppressive microenvironments. Meanwhile, a better understanding of PD-L1, a major prognostic biomarker for checkpoint immune therapy, regulation may provide insights for developing novel immunotherapeutic strategies for treating gliomas. In the present study, we elucidate the functional significance of the orphan nuclear receptor TLX in human glioma, and its functional role in immune suppression through regulation of PD-L1/PD-1 axis. METHODS TLX and PD-L1 expression patterns, and their association with clinicopathological parameters and immune phenotypes of glioma were analysed using CIBERSORT algorithm and single-sample gene-set enrichment analysis from The Cancer Genome Atlas (n=695) and Chinese Glioma Genome Atlas (n=1018) databases. Protein expression and cellular localization of TLX, PD-L1, and PD-1, as well as the prevalence of cytotoxic tumor-infiltrating lymphocytes (TILs), and tumor-associated macrophages (TAMs), in the glioma immune microenvironment were analyzed via tissue microarray by immunohistochemistry and multiplex immunofluorescence. Glioma allografts and xenografts with TLX manipulation (knockdown/knockout or reverse agonist) were inoculated subcutaneously, or orthotopically into the brains of immunodeficient and immunocompetent mice to assess tumor growth by imaging, and the immune microenvironment by flow cytometry. PD-L1 transcriptional regulation by TLX was analyzed by chromatin immunoprecipitation and luciferase reporter assays. RESULTS TLX and PD-L1 expression was positively associated with macrophage-mediated immunosuppressive phenotypes in gliomas. TLX showed significant upregulation and positive correlation with PD-L1. Meanwhile, suppression of TLX significantly inhibited in vivo growth of glioma allografts and xenografts (p<0.05), rescued the antitumoral immune response, significantly decreased the PD-L1+, and glioma-associated macrophage population, and increased cytotoxic lymphocyte infiltration (p<0.05). Mechanistically, TLX binds directly to CD274 (PD-L1) gene promoter and activates CD274 transcription. CONCLUSIONS TLX contributes to glioma malignancy and immunosuppression through transcriptional activation of PD-L1 ligands that bind to PD-1 expressed on both TILs and TAMs. Thus, targeting the druggable TLX may have potential therapeutic significance in glioma immune therapy.
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Affiliation(s)
- Jiayi Zhou
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
| | - Xiaojuan Pei
- Department of Pathology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guandong, China
| | - Yingui Yang
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
| | - Zhu Wang
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong, China
| | - Weijie Gao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hongkong, China
| | - Ran Ye
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
| | - Xiantong Zhang
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
| | - Jiangang Liu
- Department of Neurosurgery, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Zhuohao Liu
- Department of Neurosurgery, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Xinzhi Yang
- Department of Neurosurgery, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Jingli Tao
- Department of Pathology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guandong, China
| | - Chunshan Gu
- Hospital Management & performance Office, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Wei Hu
- Department of Gastroenterology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Franky Lueng Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hongkong, China
| | - Xin Li
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
| | - Jie Mao
- Department of Neurosurgery, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
| | - Dinglan Wu
- Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Center (CIRC), Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, Guangdong, China
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9
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Bakhshinyan D, Savage N, Salim SK, Venugopal C, Singh SK. The Strange Case of Jekyll and Hyde: Parallels Between Neural Stem Cells and Glioblastoma-Initiating Cells. Front Oncol 2021; 10:603738. [PMID: 33489908 PMCID: PMC7820896 DOI: 10.3389/fonc.2020.603738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022] Open
Abstract
During embryonic development, radial glial precursor cells give rise to neural lineages, and a small proportion persist in the adult mammalian brain to contribute to long-term neuroplasticity. Neural stem cells (NSCs) reside in two neurogenic niches of the adult brain, the hippocampus and the subventricular zone (SVZ). NSCs in the SVZ are endowed with the defining stem cell properties of self-renewal and multipotent differentiation, which are maintained by intrinsic cellular programs, and extrinsic cellular and niche-specific interactions. In glioblastoma, the most aggressive primary malignant brain cancer, a subpopulation of cells termed glioblastoma stem cells (GSCs) exhibit similar stem-like properties. While there is an extensive overlap between NSCs and GSCs in function, distinct genetic profiles, transcriptional programs, and external environmental cues influence their divergent behavior. This review highlights the similarities and differences between GSCs and SVZ NSCs in terms of their gene expression, regulatory molecular pathways, niche organization, metabolic programs, and current therapies designed to exploit these differences.
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Affiliation(s)
- David Bakhshinyan
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Neil Savage
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Sabra Khalid Salim
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Chitra Venugopal
- Department of Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Sheila K. Singh
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
- Department of Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
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10
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Parris TZ, Vizlin-Hodzic D, Salmela S, Funa K. Tumorigenic effects of TLX overexpression in HEK 293T cells. Cancer Rep (Hoboken) 2020; 2:e1204. [PMID: 32721119 DOI: 10.1002/cnr2.1204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/28/2019] [Accepted: 06/04/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The human orphan receptor TLX (NR2E1) is a key regulator of neurogenesis, adult stem cell maintenance, and tumorigenesis. However, little is known about the genetic and transcriptomic events that occur following TLX overexpression in human cell lines. AIMS Here, we used cytogenetics and RNA sequencing to investigate the effect of TLX overexpression with an inducible vector system in the HEK 293T cell line. METHODS AND RESULTS Conventional spectral karyotyping was used to identify chromosomal abnormalities, followed by fluorescence in situ hybridization (FISH) analysis on chromosome spreads to assess TLX DNA copy number. Illumina paired-end whole transcriptome sequencing was then performed to characterize recurrent genetic variants (single nucleotide polymorphisms (SNPs) and indels), expressed gene fusions, and gene expression profiles. Lastly, flow cytometry was used to analyze cell cycle distribution. Intriguingly, we show that upon transfection with a vector containing the human TLX gene (eGFP-hTLX), an isochromosome forms on the long arm of chromosome 6, thereby resulting in DNA gain of the TLX locus (6q21) and upregulation of TLX. Induction of the eGFP-hTLX vector further increased TLX expression levels, leading to G0-G1 cell cycle arrest, genetic aberrations, modulation of gene expression patterns, and crosstalk with other nuclear receptors (AR, ESR1, ESR2, NR1H4, and NR3C2). We identified a 49-gene signature associated with central nervous system (CNS) development and carcinogenesis, in addition to potentially cancer-driving gene fusions (LARP1-CNOT8 and NSL1-ZDBF2) and deleterious genetic variants (frameshift insertions in the CTSH, DBF4, POSTN, and WDR78 genes). CONCLUSION Taken together, these findings illustrate that TLX may play a pivotal role in tumorigenesis via genomic instability and perturbation of cancer-related processes.
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Affiliation(s)
- Toshima Z Parris
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Cancer Center, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Dzeneta Vizlin-Hodzic
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.,Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Susanne Salmela
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Cancer Center, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Keiko Funa
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Cancer Center, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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11
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Hakes AE, Brand AH. Tailless/TLX reverts intermediate neural progenitors to stem cells driving tumourigenesis via repression of asense/ASCL1. eLife 2020; 9:e53377. [PMID: 32073402 PMCID: PMC7058384 DOI: 10.7554/elife.53377] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/19/2020] [Indexed: 02/06/2023] Open
Abstract
Understanding the sequence of events leading to cancer relies in large part upon identifying the tumour cell of origin. Glioblastoma is the most malignant brain cancer but the early stages of disease progression remain elusive. Neural lineages have been implicated as cells of origin, as have glia. Interestingly, high levels of the neural stem cell regulator TLX correlate with poor patient prognosis. Here we show that high levels of the Drosophila TLX homologue, Tailless, initiate tumourigenesis by reverting intermediate neural progenitors to a stem cell state. Strikingly, we could block tumour formation completely by re-expressing Asense (homologue of human ASCL1), which we show is a direct target of Tailless. Our results predict that expression of TLX and ASCL1 should be mutually exclusive in glioblastoma, which was verified in single-cell RNA-seq of human glioblastoma samples. Counteracting high TLX is a potential therapeutic strategy for suppressing tumours originating from intermediate progenitor cells.
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Affiliation(s)
- Anna E Hakes
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
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12
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Orphan nuclear receptor TLX contributes to androgen insensitivity in castration-resistant prostate cancer via its repression of androgen receptor transcription. Oncogene 2018; 37:3340-3355. [PMID: 29555975 PMCID: PMC6013422 DOI: 10.1038/s41388-018-0198-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 01/11/2018] [Accepted: 02/03/2018] [Indexed: 02/03/2023]
Abstract
The metastatic castration-resistant prostate cancer (CRPC) is a lethal form of prostate cancer, in which the expression of androgen receptor (AR) is highly heterogeneous. Indeed, lower AR expression and attenuated AR signature activity is shown in CRPC tissues, especially in the subset of neuroendocrine prostate cancer (NEPC) and prostate cancer stem-like cells (PCSCs). However, the significance of AR downregulation in androgen insensitivity and de-differentiation of tumor cells in CRPC is poorly understood and much neglected. Our previous study shows that the orphan nuclear receptor TLX (NR2E1), which is upregulated in prostate cancer, plays an oncogenic role in prostate carcinogenesis by suppressing oncogene-induced senescence. In the present study, we further established that TLX exhibited an increased expression in metastatic CRPC. Further analyses showed that overexpression of TLX could confer resistance to androgen deprivation and anti-androgen in androgen-dependent prostate cancer cells in vitro and in vivo, whereas knockdown of endogenous TLX could potentiate the sensitivity to androgen deprivation and anti-androgen in prostate cancer cells. Our study revealed that the TLX-induced resistance to androgen deprivation and anti-androgen was mediated through its direct suppression of AR gene transcription and signaling in both androgen-stimulated and -unstimulated prostate cancer cells. We also characterized that TLX could bind directly to AR promoter and repress AR transcription by recruitment of histone modifiers, including HDAC1, HDAC3, and LSD1. Together, our present study shows, for the first time, that TLX can contribute to androgen insensitivity in CRPC via repression of AR gene transcription and signaling, and also implicates that targeting the druggable TLX may have a potential therapeutic significance in CRPC management, particularly in NEPC and PCSCs.
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13
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Gkikas D, Tsampoula M, Politis PK. Nuclear receptors in neural stem/progenitor cell homeostasis. Cell Mol Life Sci 2017; 74:4097-4120. [PMID: 28638936 PMCID: PMC11107725 DOI: 10.1007/s00018-017-2571-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/06/2017] [Accepted: 06/13/2017] [Indexed: 12/13/2022]
Abstract
In the central nervous system, embryonic and adult neural stem/progenitor cells (NSCs) generate the enormous variety and huge numbers of neuronal and glial cells that provide structural and functional support in the brain and spinal cord. Over the last decades, nuclear receptors and their natural ligands have emerged as critical regulators of NSC homeostasis during embryonic development and adult life. Furthermore, substantial progress has been achieved towards elucidating the molecular mechanisms of nuclear receptors action in proliferative and differentiation capacities of NSCs. Aberrant expression or function of nuclear receptors in NSCs also contributes to the pathogenesis of various nervous system diseases. Here, we review recent advances in our understanding of the regulatory roles of steroid, non-steroid, and orphan nuclear receptors in NSC fate decisions. These studies establish nuclear receptors as key therapeutic targets in brain diseases.
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Affiliation(s)
- Dimitrios Gkikas
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece
| | - Matina Tsampoula
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece
| | - Panagiotis K Politis
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece.
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14
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O'Léime CS, Cryan JF, Nolan YM. Nuclear deterrents: Intrinsic regulators of IL-1β-induced effects on hippocampal neurogenesis. Brain Behav Immun 2017; 66:394-412. [PMID: 28751020 DOI: 10.1016/j.bbi.2017.07.153] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/15/2017] [Accepted: 07/23/2017] [Indexed: 12/11/2022] Open
Abstract
Hippocampal neurogenesis, the process by which new neurons are born and develop into the host circuitry, begins during embryonic development and persists throughout adulthood. Over the last decade considerable insights have been made into the role of hippocampal neurogenesis in cognitive function and the cellular mechanisms behind this process. Additionally, an increasing amount of evidence exists on the impact of environmental factors, such as stress and neuroinflammation on hippocampal neurogenesis and subsequent impairments in cognition. Elevated expression of the pro-inflammatory cytokine interleukin-1β (IL-1β) in the hippocampus is established as a significant contributor to the neuronal demise evident in many neurological and psychiatric disorders and is now known to negatively regulate hippocampal neurogenesis. In order to prevent the deleterious effects of IL-1β on neurogenesis it is necessary to identify signalling pathways and regulators of neurogenesis within neural progenitor cells that can interact with IL-1β. Nuclear receptors are ligand regulated transcription factors that are involved in modulating a large number of cellular processes including neurogenesis. In this review we focus on the signalling mechanisms of specific nuclear receptors involved in regulating neurogenesis (glucocorticoid receptors, peroxisome proliferator activated receptors, estrogen receptors, and nuclear receptor subfamily 2 group E member 1 (NR2E1 or TLX)). We propose that these nuclear receptors could be targeted to inhibit neuroinflammatory signalling pathways associated with IL-1β. We discuss their potential to be therapeutic targets for neuroinflammatory disorders affecting hippocampal neurogenesis and associated cognitive function.
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Affiliation(s)
- Ciarán S O'Léime
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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15
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Kozareva DA, Hueston CM, Ó'Léime CS, Crotty S, Dockery P, Cryan JF, Nolan YM. Absence of the neurogenesis-dependent nuclear receptor TLX induces inflammation in the hippocampus. J Neuroimmunol 2017; 331:87-96. [PMID: 28844503 DOI: 10.1016/j.jneuroim.2017.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 12/25/2022]
Abstract
The orphan nuclear receptor TLX (Nr2e1) is a key regulator of hippocampal neurogenesis. Impaired adult hippocampal neurogenesis has been reported in neurodegenerative and psychiatric conditions including dementia and stress-related depression. Neuroinflammation is also implicated in the neuropathology of these disorders, and has been shown to negatively affect hippocampal neurogenesis. To investigate a role for TLX in hippocampal neuroinflammation, we assessed microglial activation in the hippocampus of mice with a spontaneous deletion of TLX. Results from our study suggest that a lack of TLX is implicated in deregulation of microglial phenotype and that consequently, the survival and function of newborn cells in the hippocampus is impaired. TLX may be an important target in understanding inflammatory-associated impairments in neurogenesis.
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Affiliation(s)
- Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Ciarán S Ó'Léime
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Suzanne Crotty
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Peter Dockery
- Department of Anatomy, National University of Ireland, Galway, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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16
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17
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Wu D, Cheung A, Wang Y, Yu S, Chan FL. The emerging roles of orphan nuclear receptors in prostate cancer. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1866:23-36. [PMID: 27264242 DOI: 10.1016/j.bbcan.2016.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/25/2022]
Abstract
Orphan nuclear receptors are members of the nuclear receptor (NR) superfamily and are so named because their endogenous physiological ligands are either unknown or may not exist. Because of their important regulatory roles in many key physiological processes, dysregulation of signalings controlled by these receptors is associated with many diseases including cancer. Over years, studies of orphan NRs have become an area of great interest because their specific physiological and pathological roles have not been well-defined, and some of them are promising drug targets for diseases. The recently identified synthetic small molecule ligands, acting as agonists or antagonists, to these orphan NRs not only help to understand better their functional roles but also highlight that the signalings mediated by these ligand-independent NRs in diseases could be therapeutically intervened. This review is a summary of the recent advances in elucidating the emerging functional roles of orphan NRs in cancers, especially prostate cancer. In particular, some orphan NRs, RORγ, TR2, TR4, COUP-IFII, ERRα, DAX1 and SHP, exhibit crosstalk or interference with androgen receptor (AR) signaling in either normal or malignant prostatic cells, highlighting their involvement in prostate cancer progression as androgen and AR signaling pathway play critical roles in this process. We also propose that a better understanding of the mechanism of actions of these orphan NRs in prostate gland or prostate cancer could help to evaluate their potential value as therapeutic targets for prostate cancer.
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Affiliation(s)
- Dinglan Wu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Alyson Cheung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Yuliang Wang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Shan Yu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Franky L Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
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18
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Lin ML, Patel H, Remenyi J, Banerji CRS, Lai CF, Periyasamy M, Lombardo Y, Busonero C, Ottaviani S, Passey A, Quinlan PR, Purdie CA, Jordan LB, Thompson AM, Finn RS, Rueda OM, Caldas C, Gil J, Coombes RC, Fuller-Pace FV, Teschendorff AE, Buluwela L, Ali S. Expression profiling of nuclear receptors in breast cancer identifies TLX as a mediator of growth and invasion in triple-negative breast cancer. Oncotarget 2016; 6:21685-703. [PMID: 26280373 PMCID: PMC4673296 DOI: 10.18632/oncotarget.3942] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/30/2015] [Indexed: 01/23/2023] Open
Abstract
The Nuclear Receptor (NR) superfamily of transcription factors comprises 48 members, several of which have been implicated in breast cancer. Most important is estrogen receptor-α (ERα), which is a key therapeutic target. ERα action is facilitated by co-operativity with other NR and there is evidence that ERα function may be recapitulated by other NRs in ERα-negative breast cancer. In order to examine the inter-relationships between nuclear receptors, and to obtain evidence for previously unsuspected roles for any NRs, we undertook quantitative RT-PCR and bioinformatics analysis to examine their expression in breast cancer. While most NRs were expressed, bioinformatic analyses differentiated tumours into distinct prognostic groups that were validated by analyzing public microarray data sets. Although ERα and progesterone receptor were dominant in distinguishing prognostic groups, other NR strengthened these groups. Clustering analysis identified several family members with potential importance in breast cancer. Specifically, RORγ is identified as being co-expressed with ERα, whilst several NRs are preferentially expressed in ERα-negative disease, with TLX expression being prognostic in this subtype. Functional studies demonstrated the importance of TLX in regulating growth and invasion in ERα-negative breast cancer cells.
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Affiliation(s)
- Meng-Lay Lin
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Hetal Patel
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Judit Remenyi
- Division of Cancer Research, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Christopher R S Banerji
- Statistical Genomics Group, UCL Cancer Institute, University College London, London, UK.,Centre of Mathematics and Physics in Life & Experimental Sciences, University College London, London, UK
| | - Chun-Fui Lai
- Department of Surgery & Cancer, Imperial College London, London, UK
| | | | - Ylenia Lombardo
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Claudia Busonero
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Silvia Ottaviani
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Alun Passey
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Philip R Quinlan
- Dundee Cancer Centre, Clinical Research Centre, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Colin A Purdie
- Dundee Cancer Centre, Clinical Research Centre, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Lee B Jordan
- Dundee Cancer Centre, Clinical Research Centre, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Alastair M Thompson
- Department of Surgical Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | | | - Oscar M Rueda
- Cancer Research UK Cambridge Institute, University of Cambridge Li Ka Shing Centre, Cambridge, UK
| | - Carlos Caldas
- Cancer Research UK Cambridge Institute, University of Cambridge Li Ka Shing Centre, Cambridge, UK
| | - Jesus Gil
- Cell Proliferation Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London, UK
| | | | - Frances V Fuller-Pace
- Division of Cancer Research, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Andrew E Teschendorff
- Statistical Genomics Group, UCL Cancer Institute, University College London, London, UK.,Centre of Mathematics and Physics in Life & Experimental Sciences, University College London, London, UK
| | - Laki Buluwela
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Simak Ali
- Department of Surgery & Cancer, Imperial College London, London, UK
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19
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Jeyapalan JN, Doctor GT, Jones TA, Alberman SN, Tep A, Haria CM, Schwalbe EC, Morley ICF, Hill AA, LeCain M, Ottaviani D, Clifford SC, Qaddoumi I, Tatevossian RG, Ellison DW, Sheer D. DNA methylation analysis of paediatric low-grade astrocytomas identifies a tumour-specific hypomethylation signature in pilocytic astrocytomas. Acta Neuropathol Commun 2016; 4:54. [PMID: 27229157 PMCID: PMC4882864 DOI: 10.1186/s40478-016-0323-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/04/2016] [Indexed: 12/30/2022] Open
Abstract
Low-grade gliomas (LGGs) account for about a third of all brain tumours in children. We conducted a detailed study of DNA methylation and gene expression to improve our understanding of the biology of pilocytic and diffuse astrocytomas. Pilocytic astrocytomas were found to have a distinctive signature at 315 CpG sites, of which 312 were hypomethylated and 3 were hypermethylated. Genomic analysis revealed that 182 of these sites are within annotated enhancers. The signature was not present in diffuse astrocytomas, or in published profiles of other brain tumours and normal brain tissue. The AP-1 transcription factor was predicted to bind within 200 bp of a subset of the 315 differentially methylated CpG sites; the AP-1 factors, FOS and FOSL1 were found to be up-regulated in pilocytic astrocytomas. We also analysed splice variants of the AP-1 target gene, CCND1, which encodes cell cycle regulator cyclin D1. CCND1a was found to be highly expressed in both pilocytic and diffuse astrocytomas, but diffuse astrocytomas have far higher expression of the oncogenic variant, CCND1b. These findings highlight novel genetic and epigenetic differences between pilocytic and diffuse astrocytoma, in addition to well-described alterations involving BRAF, MYB and FGFR1.
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Affiliation(s)
- Jennie N Jeyapalan
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Gabriel T Doctor
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Tania A Jones
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Samuel N Alberman
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Alexander Tep
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Chirag M Haria
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Edward C Schwalbe
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Isabel C F Morley
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Alfred A Hill
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Magdalena LeCain
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Diego Ottaviani
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Steven C Clifford
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - Ibrahim Qaddoumi
- Department of Oncology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Ruth G Tatevossian
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, 38105-3678, USA
| | - David W Ellison
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, 38105-3678, USA.
| | - Denise Sheer
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK.
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20
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Benod C, Villagomez R, Webb P. TLX: An elusive receptor. J Steroid Biochem Mol Biol 2016; 157:41-7. [PMID: 26554934 DOI: 10.1016/j.jsbmb.2015.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 06/30/2015] [Accepted: 11/04/2015] [Indexed: 12/11/2022]
Abstract
TLX (tailless receptor) is a member of the nuclear receptor superfamily and belongs to a class of nuclear receptors for which no endogenous or synthetic ligands have yet been identified. TLX is a promising therapeutic target in neurological disorders and brain tumors. Thus, regulatory ligands for TLX need to be identified to complete the validation of TLX as a useful target and would serve as chemical probes to pursue the study of this receptor in disease models. It has recently been proved that TLX is druggable. However, to identify potent and specific TLX ligands with desirable biological activity, a deeper understanding of where ligands bind, how they alter TLX conformation and of the mechanism by which TLX mediates the transcription of its target genes is needed. While TLX is in the process of escaping from orphanhood, future ligand design needs to progress in parallel with improved understanding of (i) the binding cavity or surfaces to target with small molecules on the TLX ligand binding domain and (ii) the nature of the TLX coregulators in particular cell and disease contexts. Both of these topics are discussed in this review.
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Affiliation(s)
- Cindy Benod
- Department of Genomic Medicine, Houston Methodist Research Institute (HMRI), 6670 Bertner Avenue, Houston, TX 77030, USA.
| | - Rosa Villagomez
- Department of Genomic Medicine, Houston Methodist Research Institute (HMRI), 6670 Bertner Avenue, Houston, TX 77030, USA
| | - Paul Webb
- Department of Genomic Medicine, Houston Methodist Research Institute (HMRI), 6670 Bertner Avenue, Houston, TX 77030, USA
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21
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Hubert CG, Rivera M, Spangler LC, Wu Q, Mack SC, Prager BC, Couce M, McLendon RE, Sloan AE, Rich JN. A Three-Dimensional Organoid Culture System Derived from Human Glioblastomas Recapitulates the Hypoxic Gradients and Cancer Stem Cell Heterogeneity of Tumors Found In Vivo. Cancer Res 2016; 76:2465-77. [PMID: 26896279 DOI: 10.1158/0008-5472.can-15-2402] [Citation(s) in RCA: 404] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/25/2016] [Indexed: 12/18/2022]
Abstract
Many cancers feature cellular hierarchies that are driven by tumor-initiating cancer stem cells (CSC) and rely on complex interactions with the tumor microenvironment. Standard cell culture conditions fail to recapitulate the original tumor architecture or microenvironmental gradients and are not designed to retain the cellular heterogeneity of parental tumors. Here, we describe a three-dimensional culture system that supports the long-term growth and expansion of tumor organoids derived directly from glioblastoma specimens, including patient-derived primary cultures, xenografts, genetically engineered glioma models, or patient samples. Organoids derived from multiple regions of patient tumors retain selective tumorigenic potential. Furthermore, organoids could be established directly from brain metastases not typically amenable to in vitro culture. Once formed, tumor organoids grew for months and displayed regional heterogeneity with a rapidly dividing outer region of SOX2(+), OLIG2(+), and TLX(+) cells surrounding a hypoxic core of primarily non-stem senescent cells and diffuse, quiescent CSCs. Notably, non-stem cells within organoids were sensitive to radiotherapy, whereas adjacent CSCs were radioresistant. Orthotopic transplantation of patient-derived organoids resulted in tumors displaying histologic features, including single-cell invasiveness, that were more representative of the parental tumor compared with those formed from patient-derived sphere cultures. In conclusion, we present a new ex vivo model in which phenotypically diverse stem and non-stem glioblastoma cell populations can be simultaneously cultured to explore new facets of microenvironmental influences and CSC biology. Cancer Res; 76(8); 2465-77. ©2016 AACR.
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Affiliation(s)
- Christopher G Hubert
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Maricruz Rivera
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Lisa C Spangler
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Qiulian Wu
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Stephen C Mack
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Briana C Prager
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Marta Couce
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, Ohio
| | - Roger E McLendon
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Andrew E Sloan
- Center for Brain Tumor and Neuro-Oncology, Department of Neurological Surgery, Neurological Institute and Seidman Cancer Center, Case School of Medicine, University Hospitals Case Medical Center, Cleveland, Ohio
| | - Jeremy N Rich
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
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22
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Cui Q, Yang S, Ye P, Tian E, Sun G, Zhou J, Sun G, Liu X, Chen C, Murai K, Zhao C, Azizian KT, Yang L, Warden C, Wu X, D'Apuzzo M, Brown C, Badie B, Peng L, Riggs AD, Rossi JJ, Shi Y. Downregulation of TLX induces TET3 expression and inhibits glioblastoma stem cell self-renewal and tumorigenesis. Nat Commun 2016; 7:10637. [PMID: 26838672 PMCID: PMC4742843 DOI: 10.1038/ncomms10637] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 01/05/2016] [Indexed: 12/31/2022] Open
Abstract
Glioblastomas have been proposed to be maintained by highly tumorigenic glioblastoma stem cells (GSCs) that are resistant to current therapy. Therefore, targeting GSCs is critical for developing effective therapies for glioblastoma. In this study, we identify the regulatory cascade of the nuclear receptor TLX and the DNA hydroxylase Ten eleven translocation 3 (TET3) as a target for human GSCs. We show that knockdown of TLX expression inhibits human GSC tumorigenicity in mice. Treatment of human GSC-grafted mice with viral vector-delivered TLX shRNA or nanovector-delivered TLX siRNA inhibits tumour development and prolongs survival. Moreover, we identify TET3 as a potent tumour suppressor downstream of TLX to regulate the growth and self-renewal in GSCs. This study identifies the TLX-TET3 axis as a potential therapeutic target for glioblastoma. TLX is a nuclear receptor essential for neural stem cell self-renewal and recently involved in glioblastoma development. In this study, the authors show that inhibition of TLX expression, achieved using a dendrimer nanovector-delivered siRNAs or viral vector-delivered shRNAs, reduces glioblastoma stem cells self renewal and in vivo tumour growth through activation of TET3.
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Affiliation(s)
- Qi Cui
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Su Yang
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Peng Ye
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - E Tian
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Guoqiang Sun
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Jiehua Zhou
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Guihua Sun
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Xiaoxuan Liu
- Aix-Marseille Université, CNRS, UMR 7325, Centre Interdisciplinaire de Nanoscience de Marseille, 13288 Marseille, France
| | - Chao Chen
- Aix-Marseille Université, CNRS, UMR 7325, Centre Interdisciplinaire de Nanoscience de Marseille, 13288 Marseille, France
| | - Kiyohito Murai
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Chunnian Zhao
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Krist T Azizian
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Lu Yang
- Integrative Genomics Core, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Charles Warden
- Integrative Genomics Core, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Xiwei Wu
- Integrative Genomics Core, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Massimo D'Apuzzo
- Department of Pathology, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Christine Brown
- Department of Hematology and Hematopoietic Cell Transplantation, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Behnam Badie
- Department of Surgery, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Ling Peng
- Aix-Marseille Université, CNRS, UMR 7325, Centre Interdisciplinaire de Nanoscience de Marseille, 13288 Marseille, France
| | - Arthur D Riggs
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - John J Rossi
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA.,Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
| | - Yanhong Shi
- Department of Developmental and Stem Cell Biology, Division of Stem Cell Biology Research, Cancer Center, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, California 91010, USA
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23
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TLX-Its Emerging Role for Neurogenesis in Health and Disease. Mol Neurobiol 2016; 54:272-280. [PMID: 26738856 PMCID: PMC5219886 DOI: 10.1007/s12035-015-9608-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/03/2015] [Indexed: 02/07/2023]
Abstract
The orphan nuclear receptor TLX, also called NR2E1, is a factor important in the regulation of neural stem cell (NSC) self-renewal, neurogenesis, and maintenance. As a transcription factor, TLX is vital for the expression of genes implicated in neurogenesis, such as DNA replication, cell cycle, adhesion and migration. It acts by way of repressing or activating target genes, as well as controlling protein-protein interactions. Growing evidence suggests that dysregulated TLX acts in the initiation and progression of human disorders of the nervous system. This review describes recent knowledge about TLX expression, structure, targets, and biological functions, relevant to maintaining adult neural stem cells related to both neuropsychiatric conditions and certain nervous system tumours.
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24
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ERKAN EP, VURGUN U, ERBAYRAKTAR RS, ERBAYRAKTAR Z. Glioblastoma stem cells: a therapeutic challenge. Turk J Biol 2016. [DOI: 10.3906/biy-1508-79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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25
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Abstract
In this issue of Cell Stem Cell, Zhu et al. (2014) demonstrate that a genetically engineered glioma model displays a functional cellular hierarchy defined by expression of the nuclear orphan receptor Tlx. Targeting cancer stem cells through genetic deletion of TLX promotes cancer stem cell death and differentiation and extends survival.
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Affiliation(s)
- Qi Xie
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland, OH 44195, USA
| | - William A Flavahan
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland, OH 44195, USA
| | - Shideng Bao
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland, OH 44195, USA
| | - Jeremy Rich
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland, OH 44195, USA.
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26
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Zhi X, Zhou XE, He Y, Searose-Xu K, Zhang CL, Tsai CC, Melcher K, Xu HE. Structural basis for corepressor assembly by the orphan nuclear receptor TLX. Genes Dev 2015; 29:440-50. [PMID: 25691470 PMCID: PMC4335298 DOI: 10.1101/gad.254904.114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The orphan nuclear receptor TLX regulates neural stem cell self-renewal in the adult brain and functions primarily as a transcription repressor through recruitment of Atrophin corepressors, which bind to TLX via a conserved peptide motif termed the Atro box. Zhi et al. report crystal structures of the human and insect TLX ligand-binding domain in complex with Atro box peptides. Mutations that weaken the TLX–Atrophin interaction compromise the repressive activity of TLX. In addition, mutations of corresponding residues in other members of this class of receptors diminish their repressor activities. The orphan nuclear receptor TLX regulates neural stem cell self-renewal in the adult brain and functions primarily as a transcription repressor through recruitment of Atrophin corepressors, which bind to TLX via a conserved peptide motif termed the Atro box. Here we report crystal structures of the human and insect TLX ligand-binding domain in complex with Atro box peptides. In these structures, TLX adopts an autorepressed conformation in which its helix H12 occupies the coactivator-binding groove. Unexpectedly, H12 in this autorepressed conformation forms a novel binding pocket with residues from helix H3 that accommodates a short helix formed by the conserved ALXXLXXY motif of the Atro box. Mutations that weaken the TLX–Atrophin interaction compromise the repressive activity of TLX, demonstrating that this interaction is required for Atrophin to confer repressor activity to TLX. Moreover, the autorepressed conformation is conserved in the repressor class of orphan nuclear receptors, and mutations of corresponding residues in other members of this class of receptors diminish their repressor activities. Together, our results establish the functional conservation of the autorepressed conformation and define a key sequence motif in the Atro box that is essential for TLX-mediated repression.
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Affiliation(s)
- Xiaoyong Zhi
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA; Autophagy Research Center,
| | - X Edward Zhou
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - Yuanzheng He
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - Kelvin Searose-Xu
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - Chun-Li Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Texas 75390, USA
| | - Chih-Cheng Tsai
- Department of Cell Biology and Neuroscience, University of California at Riverside, Riverside, California 92521, USA
| | - Karsten Melcher
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - H Eric Xu
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA; Van Andel Research Institute-Shanghai Institute of Materia Medica (VARI/SIMM) Center, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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27
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Wu D, Yu S, Jia L, Zou C, Xu Z, Xiao L, Wong KB, Ng CF, Chan FL. Orphan nuclear receptor TLX functions as a potent suppressor of oncogene-induced senescence in prostate cancer via its transcriptional co-regulation of the CDKN1A
(p21WAF1
/
CIP1
) and SIRT1
genes. J Pathol 2015; 236:103-15. [DOI: 10.1002/path.4505] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Dinglan Wu
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Shan Yu
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Lin Jia
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Chang Zou
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Zhenyu Xu
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Lijia Xiao
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Kam-Bo Wong
- School of Life Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Chi-Fai Ng
- Department of Surgery; Chinese University of Hong Kong, Hong Kong; People's Republic of China
| | - Franky L Chan
- School of Biomedical Sciences; Chinese University of Hong Kong, Hong Kong; People's Republic of China
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28
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Chavali PL, Saini RKR, Zhai Q, Vizlin-Hodzic D, Venkatabalasubramanian S, Hayashi A, Johansson E, Zeng ZJ, Mohlin S, Påhlman S, Hansford L, Kaplan DR, Funa K. TLX activates MMP-2, promotes self-renewal of tumor spheres in neuroblastoma and correlates with poor patient survival. Cell Death Dis 2014; 5:e1502. [PMID: 25356871 PMCID: PMC4237266 DOI: 10.1038/cddis.2014.449] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 08/07/2014] [Accepted: 08/14/2014] [Indexed: 12/23/2022]
Abstract
Nuclear orphan receptor TLX (Drosophilatailless homolog) is essential for the maintenance of neural stem/progenitor cell self-renewal, but its role in neuroblastoma (NB) is not well understood. Here, we show that TLX is essential for the formation of tumor spheres in three different NB cell lines, when grown in neural stem cell media. We demonstrate that the knock down of TLX in IMR-32 cells diminishes its tumor sphere-forming capacity. In tumor spheres, TLX is coexpressed with the neural progenitor markers Nestin, CD133 and Oct-4. In addition, TLX is coexpressed with the migratory neural progenitor markers CD15 and matrix metalloproteinase-2 (MMP-2) in xenografts of primary NB cells from patients. Subsequently, we show the effect of TLX on the proliferative, invasive and migratory properties of IMR-32 cells. We attribute this to the recruitment of TLX to both MMP-2 and Oct-4 gene promoters, which resulted in the respective gene activation. In support of our findings, we found that TLX expression was high in NB patient tissues when compared with normal peripheral nervous system tissues. Further, the Kaplan–Meier estimator indicated a negative correlation between TLX expression and survival in 88 NB patients. Therefore, our results point at TLX being a crucial player in progression of NB, by promoting self-renewal of NB tumor-initiating cells and altering their migratory and invasive properties.
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Affiliation(s)
- P L Chavali
- 1] Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden [2] Department of Oncology, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - R K R Saini
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
| | - Q Zhai
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
| | - D Vizlin-Hodzic
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
| | - S Venkatabalasubramanian
- 1] Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden [2] School of Chemical and Biotechnology, SASTRA University, Thanjavur 613401, India
| | - A Hayashi
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
| | - E Johansson
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
| | - Z-j Zeng
- 1] Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden [2] Molecular Biology Research Center, School of Biological Science and Technology, Central South University, Changsha, China
| | - S Mohlin
- Center for Molecular Pathology, Lund University, Skåne University Hospital, Malmö SE 20502, Sweden
| | - S Påhlman
- Center for Molecular Pathology, Lund University, Skåne University Hospital, Malmö SE 20502, Sweden
| | - L Hansford
- 1] Program in Cell Biology, Hospital for Sick Children, Toronto, Canada M5G 1X8 [2] Department of Molecular Genetics, University of Toronto, Toronto, Canada M5S 1A8
| | - D R Kaplan
- 1] Program in Cell Biology, Hospital for Sick Children, Toronto, Canada M5G 1X8 [2] Department of Molecular Genetics, University of Toronto, Toronto, Canada M5S 1A8
| | - K Funa
- Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, Gothenburg SE 40530, Sweden
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29
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O'Loghlen A, Martin N, Krusche B, Pemberton H, Alonso MM, Chandler H, Brookes S, Parrinello S, Peters G, Gil J. The nuclear receptor NR2E1/TLX controls senescence. Oncogene 2014; 34:4069-4077. [PMID: 25328137 PMCID: PMC4305339 DOI: 10.1038/onc.2014.335] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/13/2014] [Accepted: 09/04/2014] [Indexed: 12/25/2022]
Abstract
The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumors including glioblastomas. Despite NR2E1 regulating targets like p21(CIP1) or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that polycomb repressive complexes also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16(INK4a) and direct repression of p21(CIP1). In addition NR2E1 expression also counteracts oncogene-induced senescence. The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer.
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Affiliation(s)
- Ana O'Loghlen
- Cell Proliferation Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London W12 0NN, UK.,Molecular Oncology Laboratory, CRUK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
| | - Nadine Martin
- Cell Proliferation Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London W12 0NN, UK
| | - Benjamin Krusche
- Cell Interactions and Cancer Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London W12 0NN, UK
| | - Helen Pemberton
- Molecular Oncology Laboratory, CRUK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
| | - Marta M Alonso
- Department of Medical Oncology, University Hospital of Navarra, Pamplona, Spain
| | - Hollie Chandler
- Molecular Oncology Laboratory, CRUK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
| | - Sharon Brookes
- Molecular Oncology Laboratory, CRUK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
| | - Simona Parrinello
- Cell Interactions and Cancer Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London W12 0NN, UK
| | - Gordon Peters
- Molecular Oncology Laboratory, CRUK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
| | - Jesús Gil
- Cell Proliferation Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London W12 0NN, UK
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30
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Islam MM, Zhang CL. TLX: A master regulator for neural stem cell maintenance and neurogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:210-6. [PMID: 24930777 DOI: 10.1016/j.bbagrm.2014.06.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/22/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022]
Abstract
The orphan nuclear receptor TLX, also known as NR2E1, is an essential regulator of neural stem cell (NSC) self-renewal, maintenance, and neurogenesis. In vertebrates, TLX is specifically localized to the neurogenic regions of the forebrain and retina throughout development and adulthood. TLX regulates the expression of genes involved in multiple pathways, such as the cell cycle, DNA replication, and cell adhesion. These roles are primarily performed through the transcriptional repression or activation of downstream target genes. Emerging evidence suggests that the misregulation of TLX might play a role in the onset and progression of human neurological disorders making this factor an ideal therapeutic target. Here, we review the current understanding of TLX function, expression, regulation, and activity significant to NSC maintenance, adult neurogenesis, and brain plasticity. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Affiliation(s)
- Mohammed M Islam
- Department of Molecular Biology, 6000 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Chun-Li Zhang
- Department of Molecular Biology, 6000 Harry Hines Blvd., Dallas, TX 75390, USA.
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31
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Targeting self-renewal in high-grade brain tumors leads to loss of brain tumor stem cells and prolonged survival. Cell Stem Cell 2014; 15:185-98. [PMID: 24835569 DOI: 10.1016/j.stem.2014.04.007] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 12/03/2013] [Accepted: 04/10/2014] [Indexed: 12/24/2022]
Abstract
Cancer stem cells (CSCs) have been suggested as potential therapeutic targets for treating malignant tumors, but the in vivo supporting evidence is still missing. Using a GFP reporter driven by the promoter of the nuclear receptor tailless (Tlx), we demonstrate that Tlx(+) cells in primary brain tumors are mostly quiescent. Lineage tracing demonstrates that single Tlx(+) cells can self-renew and generate Tlx(-) tumor cells in primary tumors, suggesting that they are brain tumor stem cells (BTSCs). After introducing a BTSC-specific knock-out of the Tlx gene in primary mouse tumors, we observed a loss of self-renewal of BTSCs and prolongation of animal survival, accompanied by induction of essential signaling pathways mediating cell-cycle arrest, cell death, and neural differentiation. Our study demonstrates the feasibility of targeting glioblastomas and indicates the suitability of BTSCs as therapeutic targets, thereby supporting the CSC hypothesis.
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32
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Qin S, Niu W, Iqbal N, Smith DK, Zhang CL. Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling. Front Neurosci 2014; 8:74. [PMID: 24782704 PMCID: PMC3989729 DOI: 10.3389/fnins.2014.00074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 03/26/2014] [Indexed: 01/17/2023] Open
Abstract
Neural stem cells (NSCs) are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates bone morphogenetic protein (BMP)-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP) and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.
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Affiliation(s)
- Song Qin
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital, Tongji University School of Medicine Shanghai, China ; Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Wenze Niu
- Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Nida Iqbal
- Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Derek K Smith
- Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Chun-Li Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
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33
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Safe S, Jin UH, Hedrick E, Reeder A, Lee SO. Minireview: role of orphan nuclear receptors in cancer and potential as drug targets. Mol Endocrinol 2013; 28:157-72. [PMID: 24295738 DOI: 10.1210/me.2013-1291] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The nuclear orphan receptors for which endogenous ligands have not been identified include nuclear receptor (NR)0B1 (adrenal hypoplasia congenita critical region on chromosome X gene), NR0B2 (small heterodimer partner), NR1D1/2 (Rev-Erbα/β), NR2C1 (testicular receptor 2), NR2C2 (testicular receptor 4), NR2E1 (tailless), NR2E3 (photoreceptor-specific NR [PNR]), NR2F1 chicken ovalbumin upstream promoter transcription factor 1 (COUP-TFI), NR2F2 (COUP-TFII), NR2F6 (v-erbA-related protein), NR4A1 (Nur77), NR4A2 (Nurr1), NR4A3 (Nor1), and NR6A1 (GCNF). These receptors play essential roles in development, cellular homeostasis, and disease including cancer where over- or underexpression of some receptors has prognostic significance for patient survival. Results of receptor knockdown or overexpression in vivo and in cancer cell lines demonstrate that orphan receptors exhibit tumor-specific pro-oncogenic or tumor suppressor-like activity. For example, COUP-TFII expression is both a positive (ovarian) and negative (prostate and breast) prognostic factor for cancer patients; in contrast, the prognostic activity of adrenal hypoplasia congenita critical region on chromosome X gene for the same tumors is the inverse of COUP-TFII. Functional studies show that Nur77 is tumor suppressor like in acute leukemia, whereas silencing Nur77 in pancreatic, colon, lung, lymphoma, melanoma, cervical, ovarian, gastric, and some breast cancer cell lines induces one or more of several responses including growth inhibition and decreased survival, migration, and invasion. Although endogenous ligands for the orphan receptors have not been identified, there is increasing evidence that different structural classes of compounds activate, inactivate, and directly bind several orphan receptors. Thus, the screening and development of selective orphan receptor modulators will have important clinical applications as novel mechanism-based agents for treating cancer patients overexpressing one or more orphan receptors and also for combined drug therapies.
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Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology (S.S., E.H., A.R.), Texas A&M University, College Station, Texas 77808; and Institute of Biosciences and Technology (S.S., U.-H.J., S.-O.L.), Texas A&M Health Science Center, Houston, Texas 77030
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Abstract
The nuclear receptor superfamily includes many receptors, identified based on their similarity to steroid hormone receptors but without a known ligand. The study of how these receptors are diversely regulated to interact with genomic regions to control a plethora of biological processes has provided critical insight into development, physiology, and the molecular pathology of disease. Here we provide a compendium of these so-called orphan receptors and focus on what has been learned about their modes of action, physiological functions, and therapeutic promise.
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Affiliation(s)
- Shannon E Mullican
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Choi E, Choi E, Hwang KC. MicroRNAs as novel regulators of stem cell fate. World J Stem Cells 2013; 5:172-187. [PMID: 24179605 PMCID: PMC3812521 DOI: 10.4252/wjsc.v5.i4.172] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/13/2013] [Accepted: 08/17/2013] [Indexed: 02/06/2023] Open
Abstract
Mounting evidence in stem cell biology has shown that microRNAs (miRNAs) play a crucial role in cell fate specification, including stem cell self-renewal, lineage-specific differentiation, and somatic cell reprogramming. These functions are tightly regulated by specific gene expression patterns that involve miRNAs and transcription factors. To maintain stem cell pluripotency, specific miRNAs suppress transcription factors that promote differentiation, whereas to initiate differentiation, lineage-specific miRNAs are upregulated via the inhibition of transcription factors that promote self-renewal. Small molecules can be used in a similar manner as natural miRNAs, and a number of natural and synthetic small molecules have been isolated and developed to regulate stem cell fate. Using miRNAs as novel regulators of stem cell fate will provide insight into stem cell biology and aid in understanding the molecular mechanisms and crosstalk between miRNAs and stem cells. Ultimately, advances in the regulation of stem cell fate will contribute to the development of effective medical therapies for tissue repair and regeneration. This review summarizes the current insights into stem cell fate determination by miRNAs with a focus on stem cell self-renewal, differentiation, and reprogramming. Small molecules that control stem cell fate are also highlighted.
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Konefal S, Elliot M, Crespi B. The adaptive significance of adult neurogenesis: an integrative approach. Front Neuroanat 2013; 7:21. [PMID: 23882188 PMCID: PMC3712125 DOI: 10.3389/fnana.2013.00021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 06/18/2013] [Indexed: 01/15/2023] Open
Abstract
Adult neurogenesis in mammals is predominantly restricted to two brain regions, the dentate gyrus (DG) of the hippocampus and the olfactory bulb (OB), suggesting that these two brain regions uniquely share functions that mediate its adaptive significance. Benefits of adult neurogenesis across these two regions appear to converge on increased neuronal and structural plasticity that subserves coding of novel, complex, and fine-grained information, usually with contextual components that include spatial positioning. By contrast, costs of adult neurogenesis appear to center on potential for dysregulation resulting in higher risk of brain cancer or psychological dysfunctions, but such costs have yet to be quantified directly. The three main hypotheses for the proximate functions and adaptive significance of adult neurogenesis, pattern separation, memory consolidation, and olfactory spatial, are not mutually exclusive and can be reconciled into a simple general model amenable to targeted experimental and comparative tests. Comparative analysis of brain region sizes across two major social-ecological groups of primates, gregarious (mainly diurnal haplorhines, visually-oriented, and in large social groups) and solitary (mainly noctural, territorial, and highly reliant on olfaction, as in most rodents) suggest that solitary species, but not gregarious species, show positive associations of population densities and home range sizes with sizes of both the hippocampus and OB, implicating their functions in social-territorial systems mediated by olfactory cues. Integrated analyses of the adaptive significance of adult neurogenesis will benefit from experimental studies motivated and structured by ecologically and socially relevant selective contexts.
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Affiliation(s)
- Sarah Konefal
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal General HospitalMontreal, QC, Canada
| | - Mick Elliot
- Department of Biological Sciences, Simon Fraser UniversityBurnaby, BC, Canada
| | - Bernard Crespi
- Department of Biological Sciences, Simon Fraser UniversityBurnaby, BC, Canada
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