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Zhang T, Ambrodji A, Huang H, Bouchonville KJ, Etheridge AS, Schmidt RE, Bembenek BM, Temesgen ZB, Wang Z, Innocenti F, Stroka D, Diasio RB, Largiadèr CR, Offer SM. Germline cis variant determines epigenetic regulation of the anti-cancer drug metabolism gene dihydropyrimidine dehydrogenase ( DPYD). eLife 2024; 13:RP94075. [PMID: 38686795 PMCID: PMC11060711 DOI: 10.7554/elife.94075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.
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Affiliation(s)
- Ting Zhang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Alisa Ambrodji
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of BernBernSwitzerland
- Graduate School for Cellular and Biomedical Sciences, University of BernBernSwitzerland
| | - Huixing Huang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Kelly J Bouchonville
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Amy S Etheridge
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel HillChapel HillUnited States
| | - Remington E Schmidt
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Brianna M Bembenek
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Zoey B Temesgen
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Zhiquan Wang
- Division of Hematology, Department of Medicine, Mayo ClinicRochesterUnited States
| | - Federico Innocenti
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel HillChapel HillUnited States
| | - Deborah Stroka
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of BernBernSwitzerland
| | - Robert B Diasio
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
| | - Carlo R Largiadèr
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of BernBernSwitzerland
| | - Steven M Offer
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo ClinicRochesterUnited States
- Department of Pathology, University of Iowa Carver College of Medicine, University of IowaIowa CityUnited States
- Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, University of IowaIowa CityUnited States
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2
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Hu B, Liu T, Wu Z, Phan SH. P53 regulates CCAAT/Enhancer binding protein β gene expression. Gene 2023; 884:147675. [PMID: 37541559 DOI: 10.1016/j.gene.2023.147675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/13/2023] [Accepted: 07/28/2023] [Indexed: 08/06/2023]
Abstract
BACKGROUND The transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) is implicated in diverse processes and diseases. Its two isoforms, namely liver-enriched activator protein (LAP) and liver-enriched inhibitor protein (LIP) are translated from the same mRNA. They share the same C-terminal DNA binding domain except LAP has an extra N-terminal activation domain. Probably due to its higher affinity for its DNA cognate sequences, LIP can inhibit LAP transcriptional activity even at substoichiometric levels. However, the regulatory mechanism of C/EBPβ gene expression and the LAP: LIP ratio is unclear. METHODS In this study, the C/EBPβ promoter sequence was scanned for conserved P53 response element (P53RE), and binding of P53 to the C/EBPβ promoter was tested by Electrophoretic Mobility Shift Assay (EMSA) and chromatin immunoprecipitation assay. P53 over-expression and dominant negative P53 expression plasmids were transfected into rat lung fibroblasts and tested for C/EBPβ gene transcription and expression. Western blot analysis was used to test the regulation of C/EBPβ LAP and LIP isoforms. Constructs containing the LAP 5'untranslated region (5'UTR) or the LIP 5'UTR region were used to test the importance of 5'UTR in the control of C/EBPβ LAP and LIP translation. RESULTS The C/EBPβ promoter sequence was found to contain a conserved P53 response element (P53RE), which binds P53 as demonstrated by Electrophoresis Mobility Shift Assay and chromatin immunoprecipitation assays. P53 over-expression suppressed while dominant negative P53 stimulated C/EBPβ gene transcription and expression. Western blot analysis showed that P53 differentially regulated the translation of the C/EBPβ LAP and LIP isoforms through the regulation of eIF4E and eIF4E-BP1. Further studies with constructs containing the LAP 5'untranslated region (5'UTR) or the LIP 5'UTR region showed that the 5'UTR is important in differential control of C/EBPβ LAP and LIP translation. CONCLUSION Analysis of the effects of P53 on C/EBPβ expression revealed a novel mechanism by which P53 could antagonize the effects of C/EBPβ on its target gene expression. For the first time, P53 is shown to be a repressor of C/EBPβ gene expression at both transcriptional and translational levels, with a differential effect in the magnitude of the effect on LAP vs. LIP isoforms.
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Affiliation(s)
- Biao Hu
- Department of Internal Medicine, University of Michigan Medical School, 1600 Huron Parkway, Ann Arbor, MI 48109 USA
| | - Tianju Liu
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA
| | - Zhe Wu
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA
| | - Sem H Phan
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA.
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3
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Matherne MG, Phillips ES, Embrey SJ, Burke CM, Machado HL. Emerging functions of C/EBPβ in breast cancer. Front Oncol 2023; 13:1111522. [PMID: 36761942 PMCID: PMC9905667 DOI: 10.3389/fonc.2023.1111522] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/05/2023] [Indexed: 01/26/2023] Open
Abstract
Breast tumorigenesis relies on complex interactions between tumor cells and their surrounding microenvironment, orchestrated by tightly regulated transcriptional networks. C/EBPβ is a key transcription factor that regulates the proliferation and differentiation of multiple cell types and modulates a variety of biological processes such as tissue homeostasis and the immune response. In addition, C/EBPβ has well-established roles in mammary gland development, is overexpressed in breast cancer, and has tumor-promoting functions. In this review, we discuss context-specific roles of C/EBPβ during breast tumorigenesis, isoform-specific gene regulation, and regulation of the tumor immune response. We present challenges in C/EBPβ biology and discuss the importance of C/EBPβ isoform-specific gene regulation in devising new therapeutic strategies.
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Affiliation(s)
- Megan G. Matherne
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, United States
| | - Emily S. Phillips
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, United States
| | - Samuel J. Embrey
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, United States
| | - Caitlin M. Burke
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, United States
| | - Heather L. Machado
- Department of Biochemistry and Molecular Biology, Tulane School of Medicine, New Orleans, LA, United States,Tulane Cancer Center, Louisiana Cancer Research Consortium, New Orleans, LA, United States,*Correspondence: Heather L. Machado,
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4
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Pagnotta P, Gantov M, Fletcher S, Lombardi A, Crosbie ML, Santiso N, Ursino A, Frascarolli C, Amato A, Dreszman R, Calvo JC, Toneatto J. Peritumoral adipose tissue promotes lipolysis and white adipocytes browning by paracrine action. Front Endocrinol (Lausanne) 2023; 14:1144016. [PMID: 37181035 PMCID: PMC10170974 DOI: 10.3389/fendo.2023.1144016] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/07/2023] [Indexed: 05/16/2023] Open
Abstract
Background Stromal adipocytes and tumor breast epithelial cells undergo a mutual metabolic adaptation within tumor microenvironment. Therefore, browning and lipolysis occur in cancer associated adipocytes (CAA). However, the paracrine effects of CAA on lipid metabolism and microenvironment remodeling remain poorly understood. Methods To analyze these changes, we evaluated the effects of factors in conditioned media (CM) derived from explants of human breast adipose tissue from tumor (hATT) or normal (hATN) on morphology, degree of browning, the levels of adiposity, maturity, and lipolytic-related markers in 3T3-L1 white adipocytes by Western blot, indirect immunofluorescence and lipolytic assay. We analyzed subcellular localization of UCP1, perilipin 1 (Plin1), HSL and ATGL in adipocytes incubated with different CM by indirect immunofluorescence. Additionally, we evaluated changes in adipocyte intracellular signal pathways. Results We found that adipocytes incubated with hATT-CM displayed characteristics that morphologically resembled beige/brown adipocytes with smaller cell size and higher number of small and micro lipid droplets (LDs), with less triglyceride content. Both, hATT-CM and hATN-CM, increased Pref-1, C/EBPβ LIP/LAP ratio, PPARγ, and caveolin 1 expression in white adipocytes. UCP1, PGC1α and TOMM20 increased only in adipocytes that were treated with hATT-CM. Also, hATT-CM increased the levels of Plin1 and HSL, while decreased ATGL. hATT-CM modified the subcellular localization of the lipolytic markers, favoring their relative content around micro-LDs and induced Plin1 segregation. Furthermore, the levels of p-HSL, p-ERK and p-AKT increased in white adipocytes after incubation with hATT-CM. Conclusions In summary, these findings allow us to conclude that adipocytes attached to the tumor could induce white adipocyte browning and increase lipolysis as a means for endocrine/paracrine signaling. Thus, adipocytes from the tumor microenvironment exhibit an activated phenotype that could have been induced not only by secreted soluble factors from tumor cells but also by paracrine action from other adipocytes present in this microenvironment, suggesting a "domino effect".
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Affiliation(s)
- Priscila Pagnotta
- Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina
- Department of Biological Chemistry, Faculty of Exact and Natural Sciences, University of Buenos Aires, Buenos Aires, Argentina
| | - Mariana Gantov
- Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina
| | - Sabrina Fletcher
- Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina
| | - Antonella Lombardi
- Institute of Neurosciences (INEU) FLENI-CONICET, Buenos Aires, Argentina
| | - María Lujan Crosbie
- Breast Surgery Section, Churruca-Visca Police Medical Centre, Buenos Aires, Argentina
| | - Natalia Santiso
- Breast Surgery Section, Churruca-Visca Police Medical Centre, Buenos Aires, Argentina
| | - Anabela Ursino
- Breast Surgery Section, Churruca-Visca Police Medical Centre, Buenos Aires, Argentina
| | - Celeste Frascarolli
- Breast Surgery Section, Churruca-Visca Police Medical Centre, Buenos Aires, Argentina
| | - Alicia Amato
- Breast Surgery Section, Churruca-Visca Police Medical Centre, Buenos Aires, Argentina
| | | | - Juan Carlos Calvo
- Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina
- Department of Biological Chemistry, Faculty of Exact and Natural Sciences, University of Buenos Aires, Buenos Aires, Argentina
| | - Judith Toneatto
- Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina
- *Correspondence: Judith Toneatto,
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5
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Dörr D, Obermayer B, Weiner JM, Zimmermann K, Anania C, Wagner LK, Lyras EM, Sapozhnikova V, Lara-Astiaso D, Prósper F, Lang R, Lupiáñez DG, Beule D, Höpken UE, Leutz A, Mildner A. C/EBPβ regulates lipid metabolism and
Pparg
isoform 2 expression in alveolar macrophages. Sci Immunol 2022; 7:eabj0140. [DOI: 10.1126/sciimmunol.abj0140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Pulmonary alveolar proteinosis (PAP) is a syndrome characterized by accumulation of surfactant lipoproteins within the lung alveoli. Alveolar macrophages (AMs) are crucial for surfactant clearance, and their differentiation depends on colony-stimulating factor 2 (CSF2), which regulates the establishment of an AM-characteristic gene regulatory network. Here, we report that the transcription factor CCAAT/enhancer binding protein β (C/EBPβ) is essential for the development of the AM identity, as demonstrated by transcriptome and chromatin accessibility analysis. Furthermore, C/EBPβ-deficient AMs showed severe defects in proliferation, phagocytosis, and lipid metabolism, collectively resulting in a PAP-like syndrome. Mechanistically, the long C/EBPβ protein variants LAP* and LAP together with CSF2 signaling induced the expression of
Pparg
isoform 2 but not
Pparg
isoform 1, a molecular regulatory mechanism that was also observed in other CSF2-primed macrophages. These results uncover C/EBPβ as a key regulator of AM cell fate and shed light on the molecular networks controlling lipid metabolism in macrophages.
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Affiliation(s)
- Dorothea Dörr
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
- Institute of Biology, Humboldt University of Berlin, Berlin, Germany
| | - Benedikt Obermayer
- Core Unit Bioinformatics, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - January Mikolaj Weiner
- Core Unit Bioinformatics, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karin Zimmermann
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
| | - Chiara Anania
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetics and Sex Development Group, Berlin, Germany
| | - Lisa Katharina Wagner
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
| | - Ekaterini Maria Lyras
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
| | - Valeriia Sapozhnikova
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
| | - David Lara-Astiaso
- Advanced Genomics Laboratory, Program of Hemato-Oncology, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Felipe Prósper
- Program of Regenerative Medicine, Program of Hemato-Oncology, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Roland Lang
- Institute of Clinical Microbiology, Immunology, and Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Darío G. Lupiáñez
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetics and Sex Development Group, Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Uta E. Höpken
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
| | - Achim Leutz
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
- Institute of Biology, Humboldt University of Berlin, Berlin, Germany
| | - Alexander Mildner
- Max-Delbrück-Center for Molecular Medicine in Helmholtz Association (MDC), Berlin, Germany
- Institute of Biomedicine, Medicity University of Turku, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland
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6
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Xia Y, Qadota H, Wang ZH, Liu P, Liu X, Ye KX, Matheny CJ, Berglund K, Yu SP, Drake D, Bennett DA, Wang XC, Yankner BA, Benian GM, Ye K. Neuronal C/EBPβ/AEP pathway shortens life span via selective GABAnergic neuronal degeneration by FOXO repression. SCIENCE ADVANCES 2022; 8:eabj8658. [PMID: 35353567 PMCID: PMC8967231 DOI: 10.1126/sciadv.abj8658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 02/07/2022] [Indexed: 05/05/2023]
Abstract
The age-related cognitive decline of normal aging is exacerbated in neurodegenerative diseases including Alzheimer's disease (AD). However, it remains unclear whether age-related cognitive regulators in AD pathologies contribute to life span. Here, we show that C/EBPβ, an Aβ and inflammatory cytokine-activated transcription factor that promotes AD pathologies via activating asparagine endopeptidase (AEP), mediates longevity in a gene dose-dependent manner in neuronal C/EBPβ transgenic mice. C/EBPβ selectively triggers inhibitory GABAnergic neuronal degeneration by repressing FOXOs and up-regulating AEP, leading to aberrant neural excitation and cognitive dysfunction. Overexpression of CEBP-2 or LGMN-1 (AEP) in Caenorhabditis elegans neurons but not muscle stimulates neural excitation and shortens life span. CEBP-2 or LGMN-1 reduces daf-2 mutant-elongated life span and diminishes daf-16-induced longevity. C/EBPβ and AEP are lower in humans with extended longevity and inversely correlated with REST/FOXO1. These findings demonstrate a conserved mechanism of aging that couples pathological cognitive decline to life span by the neuronal C/EBPβ/AEP pathway.
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Affiliation(s)
- Yiyuan Xia
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Hiroshi Qadota
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Zhi-Hao Wang
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Pai Liu
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
- Neuroscience program, Laney Graduate School, Emory University, Atlanta, GA 30322, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Karen X. Ye
- Emory College of Arts and Sciences, Emory University, Atlanta, GA 30322, USA
| | - Courtney J. Matheny
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Ken Berglund
- Department of Neurosurgery, Emory University, Atlanta, GA 30322, USA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University, Atlanta, GA 30322, USA
| | - Derek Drake
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Xiao-Chuan Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | | | - Guy M. Benian
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Shenzhen, China
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7
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C/EBPβ isoform-specific regulation of migration and invasion in triple-negative breast cancer cells. NPJ Breast Cancer 2022; 8:11. [PMID: 35042889 PMCID: PMC8766495 DOI: 10.1038/s41523-021-00372-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 12/06/2021] [Indexed: 12/29/2022] Open
Abstract
The transcription factor C/EBPβ is a master regulator of mammary gland development and tissue remodelling during lactation. The CEBPB-mRNA is translated into three distinct protein isoforms named C/EBPβ-LAP1, -LAP2 and -LIP that are functionally different. The smaller isoform LIP lacks the N-terminal transactivation domains and is considered to act as an inhibitor of the transactivating LAP1/2 isoforms by competitive binding for the same DNA recognition sequences. Aberrantly high expression of LIP is associated with mammary epithelial proliferation and is found in grade III, estrogen receptor (ER) and progesterone (PR) receptor-negative human breast cancer. Here, we show that reverting the high LIP/LAP ratios in triple-negative breast cancer (TNBC) cell lines into low LIP/LAP ratios by overexpression of LAP reduces migration and matrix invasion of these TNBC cells. In addition, in untransformed MCF10A human mammary epithelial cells overexpression of LIP stimulates migration. Knockout of CEBPB in TNBC cells where LIP expression prevails, resulted in strongly reduced migration that was accompanied by a downregulation of genes involved in cell migration, extracellular matrix production and cytoskeletal remodelling, many of which are epithelial to mesenchymal transition (EMT) marker genes. Together, this study suggests that the LIP/LAP ratio is involved in regulating breast cancer cell migration and invasion. This study together with studies from others shows that understanding the functions the C/EBPβ-isoforms in breast cancer development may reveal new avenues of treatment.
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8
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Tan CP, Sinigaglia L, Gomez V, Nicholls J, Habib NA. RNA Activation-A Novel Approach to Therapeutically Upregulate Gene Transcription. Molecules 2021; 26:molecules26216530. [PMID: 34770939 PMCID: PMC8586927 DOI: 10.3390/molecules26216530] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/23/2021] [Accepted: 10/26/2021] [Indexed: 12/12/2022] Open
Abstract
RNA activation (RNAa) is a mechanism whereby RNA oligos complementary to genomic sequences around the promoter region of genes increase the transcription output of their target gene. Small activating RNA (saRNA) mediate RNAa through interaction with protein co-factors to facilitate RNA polymerase II activity and nucleosome remodeling. As saRNA are small, versatile and safe, they represent a new class of therapeutics that can rescue the downregulation of critical genes in disease settings. This review highlights our current understanding of saRNA biology and describes various examples of how saRNA are successfully used to treat various oncological, neurological and monogenic diseases. MTL-CEBPA, a first-in-class compound that reverses CEBPA downregulation in oncogenic processes using CEBPA-51 saRNA has entered clinical trial for the treatment of hepatocellular carcinoma (HCC). Preclinical models demonstrate that MTL-CEBPA reverses the immunosuppressive effects of myeloid cells and allows for the synergistic enhancement of other anticancer drugs. Encouraging results led to the initiation of a clinical trial combining MTL-CEBPA with a PD-1 inhibitor for treatment of solid tumors.
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Affiliation(s)
- Choon Ping Tan
- MiNA Therapeutics Ltd., Translation & Innovation Hub, 84 Wood Lane, London W12 0BZ, UK; (C.P.T.); (L.S.); (V.G.); (J.N.)
| | - Laura Sinigaglia
- MiNA Therapeutics Ltd., Translation & Innovation Hub, 84 Wood Lane, London W12 0BZ, UK; (C.P.T.); (L.S.); (V.G.); (J.N.)
| | - Valentí Gomez
- MiNA Therapeutics Ltd., Translation & Innovation Hub, 84 Wood Lane, London W12 0BZ, UK; (C.P.T.); (L.S.); (V.G.); (J.N.)
| | - Joanna Nicholls
- MiNA Therapeutics Ltd., Translation & Innovation Hub, 84 Wood Lane, London W12 0BZ, UK; (C.P.T.); (L.S.); (V.G.); (J.N.)
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Nagy A. Habib
- MiNA Therapeutics Ltd., Translation & Innovation Hub, 84 Wood Lane, London W12 0BZ, UK; (C.P.T.); (L.S.); (V.G.); (J.N.)
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
- Correspondence: ; Tel.: +44-(0)20-3313-8574
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9
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Lei K, Kang SS, Ahn EH, Chen C, Liao J, Liu X, Li H, Edgington-Mitchell LE, Jin L, Ye K. C/EBPβ/AEP Signaling Regulates the Oxidative Stress in Malignant Cancers, Stimulating the Metastasis. Mol Cancer Ther 2021; 20:1640-1652. [PMID: 34158346 DOI: 10.1158/1535-7163.mct-21-0019] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/07/2021] [Accepted: 06/14/2021] [Indexed: 11/16/2022]
Abstract
Solid tumors start as a local disease, but some are capable of metastasizing to the lymph nodes and distant organs. The hypoxic microenvironment, which is critical during cancer development, plays a key role in regulating cancer progression and metastasis. However, the molecular mechanisms mediating the disseminated cancer cell metastasis remain incompletely understood. Here, we show that C/EBPβ/AEP signaling that is upregulated in breast cancers mediates oxidative stress and lung metastasis, and inactivation of asparagine endopeptidase (AEP, also known as legumain) robustly regulates breast cancer reactive oxygen species (ROS) and metastasis. AEP, a protease activated in acidic conditions, is overexpressed in numerous types of cancer and promotes metastasis. Employing a breast cancer cell line MDA-MD-231, we show that C/EBPβ, an oxidative stress or inflammation-activated transcription factor, and its downstream target AEP mediate ROS production as well as migration and invasion in cancer cells. Deficiency of AEP in the MMTV-PyMT transgenic breast cancer mouse model significantly regulates oxidative stress and suppresses lung metastasis. Administration of an innovative AEP inhibitor substantially mitigates ROS production and cancer metastasis. Hence, our study demonstrates that pharmacologic inhibition of AEP activity might provide a disease-modifying strategy to suppress cancer metastasis.
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Affiliation(s)
- Kecheng Lei
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.,Neurotoxin Research Center of Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Neurological Department of Tongji Hospital, Tongji University School of Medicine, Shanghai, P.R. China
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Chun Chen
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Jianming Liao
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Hua Li
- School of Pharmacy, Tongji Medical College, Huazhong Science & Technology University, Wuhan, China
| | - Laura E Edgington-Mitchell
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.,Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, New York
| | - Lingjing Jin
- Neurotoxin Research Center of Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Neurological Department of Tongji Hospital, Tongji University School of Medicine, Shanghai, P.R. China.,Neurorehabilitation Center of Yangzhi Rehabilitation Hospital, Tongji University School of Medicine, Songjiang Disc, Shanghai, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.
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10
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Spike AJ, Rosen JM. C/EBPß Isoform Specific Gene Regulation: It's a Lot more Complicated than you Think! J Mammary Gland Biol Neoplasia 2020; 25:1-12. [PMID: 32078094 PMCID: PMC7694698 DOI: 10.1007/s10911-020-09444-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/06/2020] [Indexed: 11/29/2022] Open
Abstract
It has been almost 30 years since C/EBPß was discovered. Seminal studies have shown that C/EBPß is a master regulator of mammary gland development and has been shown to control and influence proliferation and differentiation through varying mechanisms. The single-exon C/EBPß mRNA yields at least three different protein isoforms which have diverse, specific, context-dependent, and often non-overlapping roles throughout development and breast cancer progression. These roles are dictated by a number of complex factors including: expression levels of other C/EBP family members and their stoichiometry relative to the isoform in question, binding site affinity, post-translational modifications, co-factor expression, and even hormone levels and lactogenic status. Here we summarize the historical work up to the latest findings in the field on C/EBPß in the mammary gland and in breast cancer. With the current emphasis on improving immunotherapy in breast cancer the role of specific C/EBPß isoforms in regulating specific chemokine and cytokine expression and the immune microenvironment will be of increasing interest.
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Affiliation(s)
- Aaron J Spike
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Jeffrey M Rosen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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11
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Emerging Role of C/EBPβ and Epigenetic DNA Methylation in Ageing. Trends Genet 2020; 36:71-80. [DOI: 10.1016/j.tig.2019.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/31/2019] [Accepted: 11/12/2019] [Indexed: 12/11/2022]
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12
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Adamik J, Pulugulla SH, Zhang P, Sun Q, Lontos K, Macar DA, Auron PE, Galson DL. EZH2 Supports Osteoclast Differentiation and Bone Resorption Via Epigenetic and Cytoplasmic Targets. J Bone Miner Res 2020; 35:181-195. [PMID: 31487061 PMCID: PMC7402427 DOI: 10.1002/jbmr.3863] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/17/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022]
Abstract
Key osteoclast (OCL) regulatory gene promoters in bone marrow-derived monocytes harbor bivalent histone modifications that combine activating Histone 3 lysine 4 tri-methyl (H3K4me3) and repressive H3K27me3 marks, which upon RANKL stimulation resolve into repressive or activating architecture. Enhancer of zeste homologue 2 (EZH2) is the histone methyltransferase component of the polycomb repressive complex 2, which catalyzes H3K27me3 modifications. Immunofluorescence microscopy reveals that EZH2 localization during murine osteoclastogenesis is dynamically regulated. Using EZH2 knockdown and small molecule EZH2 inhibitor GSK126, we show that EZH2 plays a critical epigenetic role in OCL precursors (OCLp) during the first 24 hours of RANKL activation. RANKL triggers EZH2 translocation into the nucleus where it represses OCL-negative regulators MafB, Irf8, and Arg1. Consistent with its cytoplasmic localization in OCLp, EZH2 methyltransferase activity is required during early RANKL signaling for phosphorylation of AKT, resulting in downstream activation of the mTOR complex, which is essential for induction of OCL differentiation. Inhibition of RANKL-induced pmTOR-pS6RP signaling by GSK126 altered the translation ratio of the C/EBPβ-LAP and C/EBPβ-LIP isoforms and reduced nuclear translocation of the inhibitory C/EBPβ-LIP, which is necessary for transcriptional repression of the OCL negative-regulatory transcription factor MafB. EZH2 in multinucleated OCL is primarily cytoplasmic and mature OCL cultured on bone segments in the presence of GSK126 exhibit defective cytoskeletal architecture and reduced resorptive activity. Here we present new evidence that EZH2 plays epigenetic and cytoplasmic roles during OCL differentiation by suppressing MafB transcription and regulating early phases of PI3K-AKT-mTOR-mediated RANKL signaling, respectively. Consistent with its cytoplasmic localization, EZH2 is required for cytoskeletal dynamics during resorption by mature OCL. Thus, EZH2 exhibits complex roles in supporting osteoclast differentiation and function. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Juraj Adamik
- Department of Medicine, Division of Hematology-Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sree H Pulugulla
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Peng Zhang
- Department of Medicine, Division of Hematology-Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Quanhong Sun
- Department of Medicine, Division of Hematology-Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Konstantinos Lontos
- Department of Medicine, Division of Hematology-Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - David A Macar
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Philip E Auron
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Deborah L Galson
- Department of Medicine, Division of Hematology-Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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13
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Salotti J, Johnson PF. Regulation of senescence and the SASP by the transcription factor C/EBPβ. Exp Gerontol 2019; 128:110752. [PMID: 31648009 DOI: 10.1016/j.exger.2019.110752] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 12/19/2022]
Abstract
Oncogene-induced senescence (OIS) serves as an important barrier to tumor progression in cells that have acquired activating mutations in RAS and other oncogenes. Senescent cells also produce a secretome known as the senescence-associated secretory phenotype (SASP) that includes pro-inflammatory cytokines and chemokines. SASP factors reinforce and propagate the senescence program and identify senescent cells to the immune system for clearance. The OIS program is executed by several transcriptional effectors that include p53, RB, NF-κB and C/EBPβ. In this review, we summarize the critical role of C/EBPβ in regulating OIS and the SASP. Post-translational modifications induced by oncogenic RAS signaling control C/EBPβ activity and dimerization, and these alterations switch C/EBPβ to a pro-senescence form during OIS. In addition, C/EBPβ is regulated by a unique 3'UTR-mediated mechanism that restrains its activity in tumor cells to facilitate senescence bypass and suppression of the SASP.
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Affiliation(s)
- Jacqueline Salotti
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Peter F Johnson
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
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14
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Ackermann T, Hartleben G, Müller C, Mastrobuoni G, Groth M, Sterken BA, Zaini MA, Youssef SA, Zuidhof HR, Krauss SR, Kortman G, de Haan G, de Bruin A, Wang ZQ, Platzer M, Kempa S, Calkhoven CF. C/EBPβ-LIP induces cancer-type metabolic reprogramming by regulating the let-7/LIN28B circuit in mice. Commun Biol 2019; 2:208. [PMID: 31240246 PMCID: PMC6572810 DOI: 10.1038/s42003-019-0461-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 05/13/2019] [Indexed: 12/18/2022] Open
Abstract
The transcription factors LAP1, LAP2 and LIP are derived from the Cebpb-mRNA through the use of alternative start codons. High LIP expression has been associated with human cancer and increased cancer incidence in mice. However, how LIP contributes to cellular transformation is poorly understood. Here we present that LIP induces aerobic glycolysis and mitochondrial respiration reminiscent of cancer metabolism. We show that LIP-induced metabolic programming is dependent on the RNA-binding protein LIN28B, a translational regulator of glycolytic and mitochondrial enzymes with known oncogenic function. LIP activates LIN28B through repression of the let-7 microRNA family that targets the Lin28b-mRNA. Transgenic mice overexpressing LIP have reduced levels of let-7 and increased LIN28B expression, which is associated with metabolic reprogramming as shown in primary bone marrow cells, and with hyperplasia in the skin. This study establishes LIP as an inducer of cancer-type metabolic reprogramming and as a regulator of the let-7/LIN28B regulatory circuit.
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Affiliation(s)
- Tobias Ackermann
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Götz Hartleben
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Christine Müller
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | | | - Marco Groth
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Britt A. Sterken
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Mohamad A. Zaini
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Sameh A. Youssef
- Dutch Molecular Pathology Centre, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, NL-3584 CL Utrecht, the Netherlands
| | - Hidde R. Zuidhof
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Sara R. Krauss
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Gertrud Kortman
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Gerald de Haan
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Alain de Bruin
- Dutch Molecular Pathology Centre, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, NL-3584 CL Utrecht, the Netherlands
| | - Zhao-Qi Wang
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Matthias Platzer
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Stefan Kempa
- Max Delbrück Center for Molecular Medicine, D-13092 Berlin, Germany
| | - Cornelis F. Calkhoven
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
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15
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Kohno S, Shiozaki Y, Keenan AL, Miyazaki-Anzai S, Miyazaki M. An N-terminal-truncated isoform of FAM134B (FAM134B-2) regulates starvation-induced hepatic selective ER-phagy. Life Sci Alliance 2019; 2:2/3/e201900340. [PMID: 31101736 PMCID: PMC6526285 DOI: 10.26508/lsa.201900340] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 12/20/2022] Open
Abstract
This study has identified a novel truncated isoform of FAM134B (FAM134B-2) that regulates starvation-induced selective ER-phagy of secretory proteins such as ApoCIII through the activation of C/EBPβ. Autophagy is a conserved system that adapts to nutrient starvation, after which proteins and organelles are degraded to recycle amino acids in response to starvation. Recently, the ER was added to the list of targets of autophagic degradation. Autophagic degradation pathways of bulk ER and the specific proteins sorted through the ER are considered key mechanisms in maintaining ER homeostasis. Four ER-resident proteins (FAM134B, CCPG1, SEC62, and RTN3) have been identified as ER-resident cargo receptors, which contain LC3-interacting regions. In this study, we identified an N-terminal–truncated isoform of FAM134B (FAM134B-2) that contributes to starvation-induced ER-related autophagy. Hepatic FAM134B-2 but not full-length FAM134B (FAM134B-1) is expressed in a fed state. Starvation drastically induces FAM134B-2 but no other ER-resident cargo receptors through transcriptional activation by C/EBPβ. C/EBPβ overexpression increases FAM134B-2 recruitment into autophagosomes and lysosomal degradation. FAM134B-2 regulates lysosomal degradation of ER-retained secretory proteins such as ApoCIII. This study demonstrates that the C/EBPβ-FAM134B-2 axis regulates starvation-induced selective ER-phagy.
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Affiliation(s)
- Shohei Kohno
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Yuji Shiozaki
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Audrey L Keenan
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Shinobu Miyazaki-Anzai
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Makoto Miyazaki
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
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16
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Mechanisms involved in the activation of C/EBPα by small activating RNA in hepatocellular carcinoma. Oncogene 2019; 38:3446-3457. [PMID: 30643190 DOI: 10.1038/s41388-018-0665-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 12/05/2018] [Accepted: 12/07/2018] [Indexed: 12/26/2022]
Abstract
Hepatocellular carcinoma (HCC) is generally accompanied by high mortality and low cure rate. CCAAT enhancer-binding proteins (CEBPs) are transcriptional regulators that play a key role in maintaining liver function. Altered expression of C/EBPα and C/EBPβ occurs in many tumours including HCC. saRNAs are small double-stranded RNAs that enhance target gene expression at the transcriptional level. In this report, we activate CEPBA with saRNAs and suppress CEBPB with siRNAs in cells that represent three different degrees of HCC. We performed functional assays to investigate the effects of enhancing C/EBPα and its downstream targets, p21 and albumin across these lines. We also used Mass-spectrometry (MS) subsequent to a ChIP pull-down assay to characterise the components of the protein complex involved in regulating saRNA function. Putative saRNA interacting protein candidates that were identified by MS were knocked-down with siRNAs to investigate its impact on saRNA activity. We confirmed CEBPA-saRNA decreased proliferation and migration in the differentiated lines (HepG3/Hep3B). The undifferentiated line (PLCPRF5) showed saRNA-induced increase in CEBPA but with no loss in proliferation. This effect was reversed when CEBPB was suppressed with CEBPB-siRNA. When interrogating saRNA mode of action; three saRNA interacting proteins, CTR9, HnRNPA2/B1 and DDX5 were identified by MS. Targeted knock-down of these two proteins (by siRNA) abrogated saRNA activity. This study provides insight into how different HCC lines are affected by CEBPA-saRNAs and that endogenous abundance of CEBPB and saRNA accessory proteins may dictate efficacy of CEBPA-saRNA when used in a therapeutic context.
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17
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Müller C, Zidek LM, Ackermann T, de Jong T, Liu P, Kliche V, Zaini MA, Kortman G, Harkema L, Verbeek DS, Tuckermann JP, von Maltzahn J, de Bruin A, Guryev V, Wang ZQ, Calkhoven CF. Reduced expression of C/EBPβ-LIP extends health and lifespan in mice. eLife 2018; 7:34985. [PMID: 29708496 PMCID: PMC5986274 DOI: 10.7554/elife.34985] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/27/2018] [Indexed: 02/06/2023] Open
Abstract
Ageing is associated with physical decline and the development of age-related diseases such as metabolic disorders and cancer. Few conditions are known that attenuate the adverse effects of ageing, including calorie restriction (CR) and reduced signalling through the mechanistic target of rapamycin complex 1 (mTORC1) pathway. Synthesis of the metabolic transcription factor C/EBPβ-LIP is stimulated by mTORC1, which critically depends on a short upstream open reading frame (uORF) in the Cebpb-mRNA. Here, we describe that reduced C/EBPβ-LIP expression due to genetic ablation of the uORF delays the development of age-associated phenotypes in mice. Moreover, female C/EBPβΔuORF mice display an extended lifespan. Since LIP levels increase upon aging in wild type mice, our data reveal an important role for C/EBPβ in the aging process and suggest that restriction of LIP expression sustains health and fitness. Thus, therapeutic strategies targeting C/EBPβ-LIP may offer new possibilities to treat age-related diseases and to prolong healthspan. The risks of major diseases including type II diabetes, cancer and Alzheimer’s are linked to the biological process of ageing. By finding ways to slow ageing, we can help more people to live longer healthier lives while avoiding these illnesses. Placing some animals on a diet that contains only two-thirds as many calories as they would normally eat can improve their fitness during old age and delay the onset of many age-related problems. It is unrealistic to expect people to control their diet to this extent, yet there may be other ways to bring about the same effects. Calorie restriction affects the activity of many different genes; for example, it causes a gene that produces a protein known as Liver-enriched Inhibitory Protein (LIP for short) to shut down. LIP controls the activity of many genes involved in metabolism, so it could be a key target for drugs to control ageing. Müller, Zidek et al. used mice that are unable to produce LIP to study this protein’s effect on ageing. The life expectancy of female mice lacking LIP increased by up to 20%. These mice were leaner, fitter, more resistant to cancer, had stronger immune systems and controlled their blood sugar levels better than normal mice. Male mice that lacked LIP did not live longer but did experience some ageing-related benefits. Genetic analysis also showed that gene activity particularly of metabolic genes is more robust in old female LIP-deficient mice and thus more similar to young control mice than old control mice. The results presented by Müller, Zidek et al. suggest that targeting the activity of the LIP gene could help to slow the ageing process. It is not yet clear whether shutting off LIP has similar beneficial effects in humans. Further research is also needed to investigate why female mice gain more benefits from a lack of LIP than males do.
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Affiliation(s)
- Christine Müller
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands.,Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | - Laura M Zidek
- Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | - Tobias Ackermann
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands
| | - Tristan de Jong
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands
| | - Peng Liu
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Verena Kliche
- Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | - Mohamad Amr Zaini
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands
| | - Gertrud Kortman
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands
| | - Liesbeth Harkema
- Dutch Molecular Pathology Centre, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Dineke S Verbeek
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Jan P Tuckermann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | | | - Alain de Bruin
- Dutch Molecular Pathology Centre, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands
| | - Zhao-Qi Wang
- Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | - Cornelis F Calkhoven
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands.,Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
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18
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Bégay V, Baumeier C, Zimmermann K, Heuser A, Leutz A. The C/EBPβ LIP isoform rescues loss of C/EBPβ function in the mouse. Sci Rep 2018; 8:8417. [PMID: 29849099 PMCID: PMC5976626 DOI: 10.1038/s41598-018-26579-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/22/2018] [Indexed: 12/26/2022] Open
Abstract
The transcription factor C/EBPβ regulates hematopoiesis, bone, liver, fat, and skin homeostasis, and female reproduction. C/EBPβ protein expression from its single transcript occurs by alternative in-frame translation initiation at consecutive start sites to generate three isoforms, two long (LAP*, LAP) and one truncated (LIP), with the same C-terminal bZip dimerization domain. The long C/EBPβ isoforms are considered gene activators, whereas the LIP isoform reportedly acts as a dominant-negative repressor. Here, we tested the putative repressor functions of the C/EBPβ LIP isoform in mice by comparing monoallelic WT or LIP knockin mice with Cebpb knockout mice, in combination with monoallelic Cebpa mice. The C/EBPβ LIP isoform was sufficient to function in coordination with C/EBPα in murine development, adipose tissue and sebocyte differentiation, and female fertility. Thus, the C/EBPβ LIP isoform likely has more physiological functions than its currently known role as a dominant-negative inhibitor, which are more complex than anticipated.
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Affiliation(s)
- Valérie Bégay
- Tumorigenesis and Cell Differentiation, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany. .,Molecular Physiology of Somatic Sensation, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany.
| | - Christian Baumeier
- Tumorigenesis and Cell Differentiation, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany.,Department of experimental Diabetology (DIAB), German Institute of Human Nutrition Potsdam-Rehbruecke (DifE), 14558, Nuthetal, Germany, German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Karin Zimmermann
- Tumorigenesis and Cell Differentiation, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany
| | - Arnd Heuser
- Pathophysiology Group, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany
| | - Achim Leutz
- Tumorigenesis and Cell Differentiation, Max Delbrueck Center for Molecular Medicine, Berlin, 13125, Berlin, Germany. .,Humboldt-University, Berlin, Institute of Biology, 10115, Berlin, Germany.
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19
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Biffo S, Manfrini N, Ricciardi S. Crosstalks between translation and metabolism in cancer. Curr Opin Genet Dev 2017; 48:75-81. [PMID: 29153483 DOI: 10.1016/j.gde.2017.10.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/26/2022]
Abstract
Albeit cancer patients' heterogeneity, all tumor cells have alterations of both metabolism and translation. The simplest explanation for this common feature is that several oncogenes coordinate a translational and metabolic reprogramming that is necessary for tumor cells to thrive. Overall, at least three oncogenic pathways, namely c-Myc, RAS and PI3K-mTOR, are known to affect both translation and metabolism by stimulating glycolysis and protein synthesis. The crosstalk between metabolite production and the translational machinery is, instead, less understood. What is known is that, on one side, translation initiation factors, such as eIF4E and eIF6, drive tumor growth and regulate metabolism through selective translation of nucleotide biosynthesis, glycolysis and fatty acid synthesis rate-limiting mRNAs, and on the other, that nutrient levels regulate the translational machinery by inducing full activity of translation factors. Therefore, translation and metabolism offer several therapeutic targets to be fully exploited in future studies.
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Affiliation(s)
- Stefano Biffo
- National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", INGM, 20122 Milano, Italy; Department of Biosciences, University of Milano, 20133 Milano, Italy.
| | - Nicola Manfrini
- National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", INGM, 20122 Milano, Italy
| | - Sara Ricciardi
- National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", INGM, 20122 Milano, Italy
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20
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Mildner A, Schönheit J, Giladi A, David E, Lara-Astiaso D, Lorenzo-Vivas E, Paul F, Chappell-Maor L, Priller J, Leutz A, Amit I, Jung S. Genomic Characterization of Murine Monocytes Reveals C/EBPβ Transcription Factor Dependence of Ly6C − Cells. Immunity 2017; 46:849-862.e7. [DOI: 10.1016/j.immuni.2017.04.018] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/22/2017] [Accepted: 04/26/2017] [Indexed: 12/11/2022]
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21
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A screening strategy for the discovery of drugs that reduce C/EBPβ-LIP translation with potential calorie restriction mimetic properties. Sci Rep 2017; 7:42603. [PMID: 28198412 PMCID: PMC5309760 DOI: 10.1038/srep42603] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/11/2017] [Indexed: 11/09/2022] Open
Abstract
An important part of the beneficial effects of calorie restriction (CR) on healthspan and lifespan is mediated through regulation of protein synthesis that is under control of the mechanistic target of rapamycin complex 1 (mTORC1). As one of its activities, mTORC1 stimulates translation into the metabolic transcription factor CCAAT/Enhancer Binding Protein β (C/EBPβ) isoform Liver-specific Inhibitory Protein (LIP). Regulation of LIP expression strictly depends on a translation re-initiation event that requires a conserved cis-regulatory upstream open reading frame (uORF) in the C/EBPβ-mRNA. We showed before that suppression of LIP in mice, reflecting reduced mTORC1-signaling at the C/EBPβ level, results in CR-type of metabolic improvements. Hence, we aim to find possibilities to pharmacologically down-regulate LIP in order to induce CR-mimetic effects. We engineered a luciferase-based cellular reporter system that acts as a surrogate for C/EBPβ-mRNA translation, emulating uORF-dependent C/EBPβ-LIP expression under different translational conditions. By using the reporter system in a high-throughput screening (HTS) strategy we identified drugs that reduce LIP. The drug Adefovir Dipivoxil passed all counter assays and increases fatty acid β-oxidation in a hepatoma cell line in a LIP-dependent manner. Therefore, these drugs that suppress translation into LIP potentially exhibit CR-mimetic properties.
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Hansberg-Pastor V, González-Arenas A, Camacho-Arroyo I. CCAAT/enhancer binding protein β negatively regulates progesterone receptor expression in human glioblastoma cells. Mol Cell Endocrinol 2017; 439:317-327. [PMID: 27663075 DOI: 10.1016/j.mce.2016.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/29/2016] [Accepted: 09/19/2016] [Indexed: 12/12/2022]
Abstract
Many progesterone (P4) actions are mediated by its intracellular receptor (PR), which has two isoforms (PR-A and PR-B) differentially transcribed from separate promoters of a single gene. In glioblastomas, the most frequent and aggressive brain tumors, PR-B is the predominant isoform. In an in silico analysis we showed putative CCAAT/Enhancer Binding Protein (C/EBP) binding sites at PR-B promoter. We evaluated the role of C/EBPβ in PR-B expression regulation in glioblastoma cell lines, which expressed different ratios of PR and C/EBPβ isoforms (LAP1, LAP2, and LIP). ChIP assays showed a significant basal binding of C/EBPβ, specific protein 1 (Sp1) and estrogen receptor alpha (ERα) to PR-B promoter. C/EBPβ knockdown increased PR-B expression and treatment with estradiol (E2) reduced C/EBPβ binding to the promoter and up-regulated PR-B expression. P4 induced genes were differently regulated when CEBP/β was silenced. These data show that C/EBPβ negatively regulates PR-B expression in glioblastoma cells.
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Affiliation(s)
- Valeria Hansberg-Pastor
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México (UNAM), Mexico
| | - Aliesha González-Arenas
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, UNAM, Mexico
| | - Ignacio Camacho-Arroyo
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, UNAM, Ciudad de México, Mexico.
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Mendoza-Villanueva D, Balamurugan K, Ali HR, Kim SR, Sharan S, Johnson RC, Merchant AS, Caldas C, Landberg G, Sterneck E. The C/EBPδ protein is stabilized by estrogen receptor α activity, inhibits SNAI2 expression and associates with good prognosis in breast cancer. Oncogene 2016; 35:6166-6176. [PMID: 27181204 PMCID: PMC5112156 DOI: 10.1038/onc.2016.156] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 02/11/2016] [Accepted: 03/14/2016] [Indexed: 12/13/2022]
Abstract
Hypoxia and inflammatory cytokines like interleukin-6 (IL-6, IL6) are strongly linked to cancer progression, and signal in part through the transcription factor Ccaat/enhancer-binding protein δ (C/EBPδ, CEBPD), which has been shown to promote mesenchymal features and malignant progression of glioblastoma. Here we report a different role for C/EBPδ in breast cancer. We found that the C/EBPδ protein is expressed in normal breast epithelial cells and in low-grade cancers. C/EBPδ protein (but not mRNA) expression correlates with estrogen receptor (ER+) and progesterone receptor (PGR) expression and longer progression-free survival of breast cancer patients. Specifically in ER+ breast cancers, CEBPD-but not the related CEBPB-mRNA in combination with IL6 correlated with lower risk of progression. Functional studies in cell lines showed that ERα promotes C/EBPδ expression at the level of protein stability by inhibition of the FBXW7 pathway. Furthermore, we found that C/EBPδ attenuates cell growth, motility and invasiveness by inhibiting expression of the SNAI2 (Slug) transcriptional repressor, which leads to expression of the cyclin-dependent kinase inhibitor CDKN1A (p21CIP1/WAF1). These findings identify a molecular mechanism by which ERα signaling reduces the aggressiveness of cancer cells, and demonstrate that C/EBPδ can have different functions in different types of cancer. Furthermore, our results support a potentially beneficial role for the IL-6 pathway specifically in ER+ breast cancer and call for further evaluation of the role of intra-tumoral IL-6 expression and of which cancers might benefit from current attempts to target the IL-6 pathway as a therapeutic strategy.
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Affiliation(s)
- Daniel Mendoza-Villanueva
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Kuppusamy Balamurugan
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - H. Raza Ali
- Cancer Research UK, Cambridge Institute, and Department of Oncology, University of Cambridge, Li Ka Shing Centre, Cambridge, U.K
| | - Su-Ryun Kim
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Shikha Sharan
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Randall C. Johnson
- CCR Collaborative Bioinformatics Resource, Advanced Biomedical Computing Center, Leidos Biomed, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Anand S. Merchant
- CCR Collaborative Bioinformatics Resource, Advanced Biomedical Computing Center, Leidos Biomed, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Carlos Caldas
- Cancer Research UK, Cambridge Institute, and Department of Oncology, University of Cambridge, Li Ka Shing Centre, Cambridge, U.K
| | - Göran Landberg
- Breakthrough Breast Cancer Unit, Institute of Cancer Sciences, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester, UK
| | - Esta Sterneck
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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Selagea L, Mishra A, Anand M, Ross J, Tucker-Burden C, Kong J, Brat DJ. EGFR and C/EBP-β oncogenic signaling is bidirectional in human glioma and varies with the C/EBP-β isoform. FASEB J 2016; 30:4098-4108. [PMID: 27572958 DOI: 10.1096/fj.201600550r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/15/2016] [Indexed: 01/06/2023]
Abstract
We investigated the intersection of epidermal growth factor receptor (EGFR) and CCAAT enhancer binding protein (C/EBP)-β signaling in glioblastoma (GBM), given that both gene products strongly influence neoplastic behavior. C/EBP-β is known to drive the mesenchymal transcriptional signature in GBM, likely through strong microenvironmental influences, whereas the genetic contributions to its up-regulation in this disease are not well described. We demonstrated that stable overexpression and activation of WT EGFR (U87MG-WT) led to elevated C/EBP-β expression, as well as enhanced nuclear translocation and DNA-binding activity, leading to up-regulation of C/EBP-β transcription and translation. Deeper investigation identified bidirectional regulation, with C/EBP-β also causing up-regulation of EGFR that was at least partially dependent on the STAT3. Based on ChIP-based studies, we also found that that the translational isoforms of C/EBP-β [liver-enriched transcription-activating protein (LAP)-1/2 and liver inhibitory protein (LIP)] have differential occupancy on STAT3 promoter and opposing roles in transcriptional regulation of STAT3 and EGFR. We further demonstrated that the shorter C/EBP-β isoform, LIP, promoted proliferation and migration of U87MG glioma cells, potentially via induction of cytokine IL-6. Our molecular dissection of EGFR and C/EBP-β pathway interactions uncovered a complex signaling network in which increased activity of either EGFR or C/EBP-β leads to the up-regulation of the other, enhancing oncogenic signaling. Disrupting the EGFR-C/EBP-β signaling axis could attenuate malignant behavior of glioblastoma.-Selagea, L., Mishra, A., Anand, M., Ross, J., Tucker-Burden, C., Kong, J., Brat, D. J. EGFR and C/EBP-β oncogenic signaling is bidirectional in human glioma and varies with the C/EBP-β isoform.
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Affiliation(s)
- Ligia Selagea
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia.,Department of Biology, Agnes Scott College, Decatur, Georgia
| | - Alok Mishra
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - Monika Anand
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - James Ross
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia.,Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia; and
| | - Carol Tucker-Burden
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - Jun Kong
- Department of Biomedical Informatics, Winship Cancer Institute, Emory University, Atlanta, Georgia
| | - Daniel J Brat
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia; .,Department of Biomedical Informatics, Winship Cancer Institute, Emory University, Atlanta, Georgia
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25
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Chu J, Cargnello M, Topisirovic I, Pelletier J. Translation Initiation Factors: Reprogramming Protein Synthesis in Cancer. Trends Cell Biol 2016; 26:918-933. [PMID: 27426745 DOI: 10.1016/j.tcb.2016.06.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/03/2016] [Accepted: 06/13/2016] [Indexed: 12/11/2022]
Abstract
Control of mRNA translation plays a crucial role in the regulation of gene expression and is critical for cellular homeostasis. Dysregulation of translation initiation factors has been documented in several pathologies including cancer. Aberrant function of translation initiation factors leads to translation reprogramming that promotes proliferation, survival, angiogenesis, and metastasis. In such context, understanding how altered levels (and presumably activity) of initiation factors can contribute to tumor initiation and/or maintenance is of major interest for the development of novel therapeutic strategies. In this review we provide an overview of translation initiation mechanisms and focus on recent findings describing the role of individual initiation factors and their aberrant activity in cancer.
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Affiliation(s)
- Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Marie Cargnello
- Lady Davis Institute, SMBD JGH, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada; Lady Davis Institute, SMBD JGH, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada.
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada; The Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada.
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Abstract
The past several years have seen dramatic leaps in our understanding of how gene expression is rewired at the translation level during tumorigenesis to support the transformed phenotype. This work has been driven by an explosion in technological advances and is revealing previously unimagined regulatory mechanisms that dictate functional expression of the cancer genome. In this Review we discuss emerging trends and exciting new discoveries that reveal how this translational circuitry contributes to specific aspects of tumorigenesis and cancer cell function, with a particular focus on recent insights into the role of translational control in the adaptive response to oncogenic stress conditions.
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Affiliation(s)
- Morgan L Truitt
- Department of Urology, University of California, San Francisco
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, USA
| | - Davide Ruggero
- Department of Urology, University of California, San Francisco
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, USA
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28
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Pulido-Salgado M, Vidal-Taboada JM, Saura J. C/EBPβ and C/EBPδ transcription factors: Basic biology and roles in the CNS. Prog Neurobiol 2015; 132:1-33. [PMID: 26143335 DOI: 10.1016/j.pneurobio.2015.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/08/2015] [Accepted: 06/16/2015] [Indexed: 02/01/2023]
Abstract
CCAAT/enhancer binding protein (C/EBP) β and C/EBPδ are transcription factors of the basic-leucine zipper class which share phylogenetic, structural and functional features. In this review we first describe in depth their basic molecular biology which includes fascinating aspects such as the regulated use of alternative initiation codons in the C/EBPβ mRNA. The physical interactions with multiple transcription factors which greatly opens the number of potentially regulated genes or the presence of at least five different types of post-translational modifications are also remarkable molecular mechanisms that modulate C/EBPβ and C/EBPδ function. In the second part, we review the present knowledge on the localization, expression changes and physiological roles of C/EBPβ and C/EBPδ in neurons, astrocytes and microglia. We conclude that C/EBPβ and C/EBPδ share two unique features related to their role in the CNS: whereas in neurons they participate in memory formation and synaptic plasticity, in glial cells they regulate the pro-inflammatory program. Because of their role in neuroinflammation, C/EBPβ and C/EBPδ in microglia are potential targets for treatment of neurodegenerative disorders. Any strategy to reduce C/EBPβ and C/EBPδ activity in neuroinflammation needs to take into account its potential side-effects in neurons. Therefore, cell-specific treatments will be required for the successful application of this strategy.
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Affiliation(s)
- Marta Pulido-Salgado
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Jose M Vidal-Taboada
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Josep Saura
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain.
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