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Wang L, Li P, Zhang X, Gu Z, Pan X, Wu Y, Li H. The role of basic leucine zipper transcription factor E4BP4 in cancer: a review and update. Mol Biol Rep 2024; 51:91. [PMID: 38193973 DOI: 10.1007/s11033-023-09079-9] [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] [Received: 07/21/2023] [Accepted: 10/25/2023] [Indexed: 01/10/2024]
Abstract
Mutations in the genes of tumor cells and the disorder of immune microenvironment are the main factors of tumor development. The sensitivity of tumor cells to chemotherapy drugs affect the treatment of tumor. Nuclear transcription factor E4BP4 is dysregulated in a variety of malignant tumors. It can suppress the transcription of NFKBIA, RASSF8, SOSTDC1, FOXO-induced genes (TRAIL, FAS, GADD45a and GADD45b) and Hepcidin, up-regulate RCAN1-1 and PRNP, activate mTOR and p38 in cancer cells. Also, E4BP4 can regulate tumor immune microenvironment. TGFb1/Smad3/E4BP4/ IFNγ axis in NK cells plays an important role in antitumor immunotherapy. Over expression of E4BP4 inhibited the development of Th17 cells by directly binding to the RORγt promoter. Moreover, recent studies have shown that E4BP4 inhibited the expression of multidrug resistance genes. In this review, we summarize the molecular mechanism of E4BP4 in cancer cellular process, the effects of E4BP4 in cancer immunotherapy and antitumor drug resistance, to provide theoretical basis for tumor treatment strategies targeting E4BP4.
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Affiliation(s)
- Liang Wang
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Peifen Li
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Xueying Zhang
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Zhenwu Gu
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Xinyu Pan
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yihao Wu
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Huanan Li
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, School of Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
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Matsui M, Kajikuri J, Kito H, Endo K, Hasegawa Y, Murate S, Ohya S. Inhibition of Interleukin 10 Transcription through the SMAD2/3 Signaling Pathway by Ca2+-Activated K+Channel KCa3.1 Activation in Human T-Cell Lymphoma HuT-78 Cells. Mol Pharmacol 2019; 95:294-302. [DOI: 10.1124/mol.118.114405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/06/2019] [Indexed: 11/22/2022] Open
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Wang Z, Wang C, Wang Y, Mo B, Wei J, Ma L, Rao L, Wang J, Yao D, Huang J, Xu Q, Yang J, Chen G, Mo B. E4BP4 facilitates glucocorticoid sensitivity of human bronchial epithelial cells via down-regulation of glucocorticoid receptor-beta. Cell Immunol 2018; 334:31-37. [PMID: 30153899 DOI: 10.1016/j.cellimm.2018.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 08/05/2018] [Accepted: 08/22/2018] [Indexed: 01/25/2023]
Abstract
It has recently been recognized that a subset of asthma patients suffer from glucocorticoid (GC) insensitivity, and glucocorticoid receptor-β (GR-β) is associated with corticosteroid resistance, but the underlying mechanisms remain unknown. Here we demonstrated that Interleukin-17A induced glucocorticoid sensitivity in human bronchial epithelial cells (16HBE) is enhanced, which is depend on E4 promoter-binding protein 4 (E4BP4) mediated GR-β expression. Our data show that the expression of E4BP4 is significantly up-regulated in 16HBE cells, and the depletion of E4BP4 dramatically decreased glucocorticoid sensitivity in IL-17A induced 16HBE cells. Mechanistic studies revealed that E4BP4 plays a crucial role in Interleukin-17A induced glucocorticoid sensitivity in 16HBE cells via down-regulating GR-β, which is probably mediated by PI3K/Akt activation. Collectively, we can draw the conclusion that E4BP4 contribute to enhance the GCs sensitivity, which may offer a new strategy for therapeutic intervention for GC-insensitive asthma.
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Affiliation(s)
- Zhixia Wang
- Department of Respiratory Medicine, Key Cite of National Clinical Resaerch Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha China
| | - Changming Wang
- Department of Respiratory Medicine, Guilin People's Hospital, Guilin, China
| | - Yanni Wang
- Department of Respiratory Medicine, Key Cite of National Clinical Resaerch Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha China
| | - Bifan Mo
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jianghong Wei
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Libing Ma
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Lizong Rao
- Department of Respiratory Medicine, Key Cite of National Clinical Resaerch Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha China
| | - Jiying Wang
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Dong Yao
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jianwei Huang
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Qing Xu
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jinghuan Yang
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Guangsheng Chen
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Biwen Mo
- Department of Respiratory Medicine, The Affiliated Hospital of Guilin Medical University, Guilin, China.
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Velmurugan BK, Chang R, Marthandam Asokan S, Chang C, Day C, Lin Y, Lin Y, Kuo W, Huang C. A minireview of E4BP4/NFIL3 in heart failure. J Cell Physiol 2018; 233:8458-8466. [DOI: 10.1002/jcp.26790] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/30/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Bharath Kumar Velmurugan
- Toxicology and Biomedicine Research Group, Faculty of Applied Sciences Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Ruey‐Lin Chang
- College of Chinese Medicine, School of Post‐Baccalaureate Chinese Medicine China Medical University Taichung Taiwan
| | | | - Chih‐Fen Chang
- Department of Internal Medicine, Division of Cardiology Taichung Armed Force Taichung General Hospital Taichung Taiwan
| | | | - Yueh‐Min Lin
- Department of Pathology Changhua Christian Hospital Changhua Taiwan
- Department of Medical Technology, Jen‐Teh Junior College of Medicine Nursing and Management Miaoli Taiwan
| | - Yuan‐Chuan Lin
- Graduate Institute of Basic Medical Science China Medical University Taichung Taiwan
| | - Wei‐Wen Kuo
- Department of Biological Science and Technology China Medical University Taichung Taiwan
| | - Chih‐Yang Huang
- Graduate Institute of Basic Medical Science China Medical University Taichung Taiwan
- Graduate Institute of Chinese Medical Science China Medical University Taichung Taiwan
- Department of Biological Science and Technology Asia University Taichung Taiwan
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Abdoul-Azize S, Dubus I, Vannier JP. Improvement of dexamethasone sensitivity by chelation of intracellular Ca2+ in pediatric acute lymphoblastic leukemia cells through the prosurvival kinase ERK1/2 deactivation. Oncotarget 2018; 8:27339-27352. [PMID: 28423696 PMCID: PMC5432339 DOI: 10.18632/oncotarget.16039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/15/2017] [Indexed: 01/08/2023] Open
Abstract
Previous studies have demonstrated that glucocorticoid hormones, including dexamethasone, induced alterations in intracellular calcium homeostasis in acute lymphoblastic leukemia (ALL) cells. However, the mechanism by which intracellular calcium homeostasis participates in dexamethasone sensitivity and resistance on ALL cells remains elusive. Here, we found that treatment of cells with dexamethasone resulted in increased intracellular calcium concentrations through store-operated calcium entry stimulation, which was curtailed by store-operated calcium channel blockers. We show that BAPTA-AM, an intracellular Ca2+ chelator, synergistically enhances dexamethasone lethality in two human ALL cell lines and in three primary specimens. This effect correlated with the inhibition of the prosurvival kinase ERK1/2 signaling pathway. Chelating intracellular calcium with Bapta-AM or inhibiting ERK1/2 with PD98059 significantly potentiated dexamethasone-induced mitochondrial membrane potential collapse, reactive oxygen species production, cytochrome c release, caspase-3 activity, and cell death. Moreover, we show that thapsigargin elevates intracellular free calcium ion level, and activates ERK1/2 signaling, resulting in the inhibition of dexamethasone-induced ALL cells apoptosis. Together, these results indicate that calcium-related ERK1/2 signaling pathway contributes to protect cells from dexamethasone sensitivity by limiting mitochondrial apoptotic pathway. This report provides a novel resistance pathway underlying the regulatory effect of dexamethasone on ALL cells.
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Affiliation(s)
- Souleymane Abdoul-Azize
- Micro-Environnement et Renouvellement Cellulaire Intégré, MERCI UPRES EA 3829, Faculté de Médecine et Pharmacie, Université de Rouen, 76183 Rouen Cedex, France.,Current address: Unité Inserm U1234/Université de Rouen/IRIB, Rouen, France
| | - Isabelle Dubus
- Micro-Environnement et Renouvellement Cellulaire Intégré, MERCI UPRES EA 3829, Faculté de Médecine et Pharmacie, Université de Rouen, 76183 Rouen Cedex, France.,Current address: Unité Inserm U1234/Université de Rouen/IRIB, Rouen, France
| | - Jean-Pierre Vannier
- Micro-Environnement et Renouvellement Cellulaire Intégré, MERCI UPRES EA 3829, Faculté de Médecine et Pharmacie, Université de Rouen, 76183 Rouen Cedex, France.,Service Immuno-Hémato-Oncologie Pédiatrique, CHU Charles Nicolle, 76031 ROUEN Cedex, France.,Current address: Unité Inserm U1234/Université de Rouen/IRIB, Rouen, France
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Sionov RV, Vlahopoulos SA, Granot Z. Regulation of Bim in Health and Disease. Oncotarget 2015; 6:23058-134. [PMID: 26405162 PMCID: PMC4695108 DOI: 10.18632/oncotarget.5492] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 08/08/2015] [Indexed: 11/25/2022] Open
Abstract
The BH3-only Bim protein is a major determinant for initiating the intrinsic apoptotic pathway under both physiological and pathophysiological conditions. Tight regulation of its expression and activity at the transcriptional, translational and post-translational levels together with the induction of alternatively spliced isoforms with different pro-apoptotic potential, ensure timely activation of Bim. Under physiological conditions, Bim is essential for shaping immune responses where its absence promotes autoimmunity, while too early Bim induction eliminates cytotoxic T cells prematurely, resulting in chronic inflammation and tumor progression. Enhanced Bim induction in neurons causes neurodegenerative disorders including Alzheimer's, Parkinson's and Huntington's diseases. Moreover, type I diabetes is promoted by genetically predisposed elevation of Bim in β-cells. On the contrary, cancer cells have developed mechanisms that suppress Bim expression necessary for tumor progression and metastasis. This review focuses on the intricate network regulating Bim activity and its involvement in physiological and pathophysiological processes.
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Affiliation(s)
- Ronit Vogt Sionov
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| | - Spiros A. Vlahopoulos
- First Department of Pediatrics, University of Athens, Horemeio Research Laboratory, Thivon and Levadias, Goudi, Athens, Greece
| | - Zvi Granot
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
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Beach JA, Nary LJ, Hovanessian R, Medh RD. Correlation of glucocorticoid-mediated E4BP4 upregulation with altered expression of pro- and anti-apoptotic genes in CEM human lymphoblastic leukemia cells. Biochem Biophys Res Commun 2014; 451:382-8. [PMID: 25101525 DOI: 10.1016/j.bbrc.2014.07.103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
Abstract
In Caenorhabditiselegans, motorneuron apoptosis is regulated via a ces-2-ces-1-egl-1 pathway. We tested whether human CEM lymphoblastic leukemia cells undergo apoptosis via an analogous pathway. We have previously shown that E4BP4, a ces-2 ortholog, mediates glucocorticoid (GC)-dependent upregulation of BIM, an egl-1 ortholog, in GC-sensitive CEM C7-14 cells and in CEM C1-15mE#3 cells, which are sensitized to GCs by ectopic expression of E4BP4. In the present study, we demonstrate that the human ces-1 orthologs, SLUG and SNAIL, are not significantly repressed in correlation with E4BP4 expression. Expression of E4BP4 homologs, the PAR family genes, especially HLF, encoding a known anti-apoptotic factor, was inverse to that of E4BP4 and BIM. Expression of pro- and anti-apoptotic genes in CEM cells was analyzed via an apoptosis PCR Array. We identified BIRC3 and BIM as genes whose expression paralleled that of E4BP4, while FASLG, TRAF4, BCL2A1, BCL2L1, BCL2L2 and CD40LG as genes whose expression was opposite to that of E4BP4.
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Affiliation(s)
- Jessica A Beach
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
| | - Laura J Nary
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
| | - Rebeka Hovanessian
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
| | - Rheem D Medh
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
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Keniry M, Dearth RK, Persans M, Parsons R. New Frontiers for the NFIL3 bZIP Transcription Factor in Cancer, Metabolism and Beyond. Discoveries (Craiova) 2014; 2:e15. [PMID: 26539561 PMCID: PMC4629104 DOI: 10.15190/d.2014.7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The bZIP transcription factor NFIL3 (Nuclear factor Interleukin 3 regulated, also known as E4 binding protein 4, E4BP4) regulates diverse biological processes from circadian rhythm to cellular viability. Recently, a host of novel roles have been identified for NFIL3 in immunological signal transduction, cancer, aging and metabolism. Elucidating the signaling pathways that are impacted by NFIL3 and the regulatory mechanisms that it targets, inhibits or activates will be critical for developing a clearer picture of its physiological roles in disease and normal processes. This review will discuss the recent advances and emerging issues regarding NFIL3-mediated transcriptional regulation of CEBPb and FOXO1 activated genes and signal transduction.
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Affiliation(s)
- Megan Keniry
- Department of Biology, University of Texas- Pan American, 1201 W. University Dr., Edinburg, TX 78539, USA
| | - Robert K Dearth
- Department of Biology, University of Texas- Pan American, 1201 W. University Dr., Edinburg, TX 78539, USA
| | - Michael Persans
- Department of Biology, University of Texas- Pan American, 1201 W. University Dr., Edinburg, TX 78539, USA
| | - Ramon Parsons
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave HCSM 6-117, New York, NY 10029, USA
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Carey KT, Tan KH, Ng J, Liddicoat DR, Godfrey DI, Cole TJ. Nfil3 is a glucocorticoid-regulated gene required for glucocorticoid-induced apoptosis in male murine T cells. Endocrinology 2013; 154:1540-52. [PMID: 23425966 DOI: 10.1210/en.2012-1820] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Glucocorticoids (GCs) have essential roles in the regulation of development, integrated metabolism, and immune and neurological responses, and act primarily via the glucocorticoid receptor (GR). In most cells, GC treatment results in down-regulation of GR mRNA and protein levels via negative feedback mechanisms. However, in GC-treated thymocytes, GR protein levels are maintained at a high level, increasing sensitivity of thymocytes to GCs, resulting in apoptosis termed glucocorticoid-induced cell death (GICD). CD4(+)CD8(+) double-positive thymocytes and thymic natural killer T cells in particular are highly sensitive to GICD. Although GICD is exploited via the use of synthetic GC analogues in the treatment of hematopoietic malignancies, the intracellular molecular pathway of GICD is not well understood. To explore GICD in thymocytes, the authors performed whole genome expression microarray analysis in mouse GR exon 2 null vs wild-type thymus RNA 3 hours after dexamethasone treatment. Identified and validated direct GR targets included P21 and Bim, in addition to an important transcriptional regulator Nfil3, which previously has been associated with GICD and is essential for natural killer cell development in vivo. Immunostaining of NFIL3 in whole thymus localized NFIL3 primarily to the medullary region, and double labeling colocalized NFIL3 to apoptotic cells. In silico analysis revealed a putative GC response element 5 kb upstream of the Nfil3 promoter that is strongly conserved in the rat genome and was confirmed to bind GR by chromatin immunoprecipitation. The knockdown of Nfil3 mRNA levels to 20% of normal using specific small interfering RNAs abrogated GICD, indicating that NFIL3 is required for normal GICD in CTLL-2 T cells.
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Affiliation(s)
- Kirstyn T Carey
- Department of Biochemistry & Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia
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E4BP4 overexpression: A protective mechanism in CD4+ T cells from SLE patients. J Autoimmun 2013; 41:152-60. [DOI: 10.1016/j.jaut.2013.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 01/02/2013] [Indexed: 11/19/2022]
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Beach JA, Nary LJ, Hirakawa Y, Holland E, Hovanessian R, Medh RD. E4BP4 facilitates glucocorticoid-evoked apoptosis of human leukemic CEM cells via upregulation of Bim. J Mol Signal 2011; 6:13. [PMID: 21975218 PMCID: PMC3197565 DOI: 10.1186/1750-2187-6-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 10/05/2011] [Indexed: 12/02/2022] Open
Abstract
Background Synthetic GCs serve as therapeutic agents for some lymphoid leukemias because of their ability to induce transcriptional changes via the GC receptor (GR) and trigger apoptosis. Upregulation of the BH3-only member of Bcl-2 family proteins, Bim, has been shown to be essential for GC-evoked apoptosis of leukemic lymphoblasts. Using human T cell leukemic sister clones CEM-C7-14 and CEM-C1-15, we have previously shown that the bZIP transcriptional repressor, E4BP4, is preferentially upregulated by GCs in CEM-C7-14 cells that are susceptible to GC-evoked apoptosis, but not in refractory CEM-C1-15 cells. E4BP4 is an evolutionarily conserved member of the PAR family of bZIP transcription factors related to the C. elegans death specification gene ces2. Results Mouse E4BP4 was ectopically expressed in CEM-C1-15 cells, resulting in sensitization to GC-evoked apoptosis in correlation with restoration of E4BP4 and Bim upregulation. shRNA mediated modest knockdown of E4BP4 in CEM-C7-14 cells resulted in concomitant reduction in Bim expression, although GC-evoked fold-induction and sensitivity to apoptosis was similar to parental cells. Conclusion Data presented here suggest that GC-mediated upregulation of E4BP4 facilitates Bim upregulation and apoptosis of CEM cells. Since the Bim promoter does not contain any consensus GRE or EBPRE sequences, induction of Bim may be a secondary response.
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Affiliation(s)
- Jessica A Beach
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
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Hirakawa Y, Medh RD, Metzenberg S. Quantitative polymerase chain reaction analysis by deconvolution of internal standard. BMC Mol Biol 2010; 11:30. [PMID: 20429911 PMCID: PMC2877679 DOI: 10.1186/1471-2199-11-30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 04/29/2010] [Indexed: 11/11/2022] Open
Abstract
Background Quantitative Polymerase Chain Reaction (qPCR) is a collection of methods for estimating the number of copies of a specific DNA template in a sample, but one that is not universally accepted because it can lead to highly inaccurate (albeit precise) results. The fundamental problem is that qPCR methods use mathematical models that explicitly or implicitly apply an estimate of amplification efficiency, the error of which is compounded in the analysis to unacceptable levels. Results We present a new method of qPCR analysis that is efficiency-independent and yields accurate and precise results in controlled experiments. The method depends on a computer-assisted deconvolution that finds the point of concordant amplification behavior between the "unknown" template and an admixed amplicon standard. We apply the method to demonstrate dexamethasone-induced changes in gene expression in lymphoblastic leukemia cell lines. Conclusions This method of qPCR analysis does not use any explicit or implicit measure of efficiency, and may therefore be immune to problems inherent in other qPCR approaches. It yields an estimate of absolute initial copy number of template, and controlled tests show it generates accurate results.
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Affiliation(s)
- Yasuko Hirakawa
- Department of Biology, California State University, 18111 Nordhoff St, Northridge, California 91330, USA
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Gascoyne DM, Long E, Veiga-Fernandes H, de Boer J, Williams O, Seddon B, Coles M, Kioussis D, Brady HJM. The basic leucine zipper transcription factor E4BP4 is essential for natural killer cell development. Nat Immunol 2009; 10:1118-24. [DOI: 10.1038/ni.1787] [Citation(s) in RCA: 335] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 07/29/2009] [Indexed: 01/12/2023]
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Hirakawa Y, Nary LJ, Medh RD. Glucocorticoid evoked upregulation of RCAN1-1 in human leukemic CEM cells susceptible to apoptosis. J Mol Signal 2009; 4:6. [PMID: 19725972 PMCID: PMC2745384 DOI: 10.1186/1750-2187-4-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 09/02/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glucocorticoid hormones (GCs) induce apoptosis of leukemic T-cells by transcriptional regulation via the GC receptor, GR. In the human leukemic CEM cell culture model, RCAN1 has been identified as one of the genes that is specifically upregulated only in the GC-sensitive CEM C7-14 cells, but not in the GC-resistant CEM-C1-15 sister cells in correlation with GC-evoked apoptosis. RCAN1 gene encodes two major protein isoforms of the regulator of calcineurin (RCAN1), RCAN1-1 and RCAN1-4 via alternative splicing of exons 1 and 4 respectively, to exons 5-7. Studies reported here evaluated the differential regulation and function of the two transcripts and protein products of RCAN1 by the synthetic GC dexamethasone (Dex), and by modulators of calcium signaling. RESULTS Dex selectively upregulates transcript specific for RCAN 1-1 in glucocorticoid (GC)-susceptible human leukemic CEM-C7-14 cells but not in GC-refractory CEM-C1-15 sister cells. Expression of the second major transcript, RCAN1-4, is upregulated by [Ca2+]i inducers, thapsigargin and A23187, but not by Dex, suggesting a mutually exclusive regulatory pathway for both RCAN1 transcripts. GC-mediated upregulation of RCAN1-1 transcript and RCAN1-1 protein was kinase dependent, and was blocked by staurosporine and the p38 MAP kinase inhibitor SB 202190. RCAN1-1 coimmunoprecipitates with calcineurin PP3C and Dex-mediated RCAN1-1 upregulation correlated with reduction in calcineurin PP3C activity. CONCLUSION Data presented here suggest that GCs specifically upregulate RCAN1-1 transcript and protein while inducers of [Ca2+]i selectively upregulate RCAN1-4. GC-mediated increase in RCAN1-1 abundance and binding possibly inhibits calcineurin activity and modulates apoptosis in CEM-C7-14 cells.
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Affiliation(s)
- Yasuko Hirakawa
- Department of Biology, California State University Northridge, Northridge, CA 91330-8303, USA.
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Silvestris F, Cafforio P, De Matteo M, Calvani N, Frassanito MA, Dammacco F. Negative regulation of the osteoblast function in multiple myeloma through the repressor gene E4BP4 activated by malignant plasma cells. Clin Cancer Res 2008; 14:6081-91. [PMID: 18829486 DOI: 10.1158/1078-0432.ccr-08-0219] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE To explore the pathogenetic mechanisms that suppress the osteoblast function in multiple myeloma because osteogenesis results in defective new bone formation and repair. EXPERIMENTAL DESIGN Microarray gene analysis revealed the overexpression of E4BP4, a transcriptional repressor gene, in normal osteoblasts cocultured with myeloma cells that were releasing the parathyroid hormone-related protein (PTHrP). Thus, the effect of E4BP4 was assessed in PTHrP-stimulated osteoblasts by measuring the RNA levels of both Runx2 and Osterix as major osteoblast transcriptional activators. Because E4BP4 is a negative regulator of the cyclooxygenase-2 (COX-2) pathway that drives the expression of both Runx2 and Osterix, these factors were investigated after prostaglandin E(2) treatment to overcome the COX-2 defect as well as in E4BP4-silenced osteoblasts. Finally, E4BP4, PTHrP, Osterix, and osteocalcin levels were measured in vivo in patients with bone disease together with the E4BP4 protein in bone biopsies. RESULTS E4BP4 was specifically induced by PTHrP and inhibited both Runx2 and Osterix, whereas E4BP4-silenced osteoblasts expressed functional levels of both factors. The prostaglandin E(2) treatment of E4BP4-up-regulated osteoblasts promptly restored Runx2 and Osterix activities, suggesting that integrity of COX-2 pathway is essential for their transcription. Down-regulation of Osterix by E4BP4 was confirmed in vivo by its inverse levels in osteoblasts from myeloma patients with increased serum PTHrP, whose bone biopsies expressed the E4BP4 protein. CONCLUSIONS Our data support the role of E4BP4 as osteoblast transcriptional repressor in inhibiting both Runx2 and Osterix in myeloma bone disease and correlate its effect with the increased PTHrP activity.
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Affiliation(s)
- Franco Silvestris
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Piazza Giulio Cesare 11, Bari, Italy.
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