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Huang CY, Su YC, Lu CY, Chiu PL, Chang YM, Ju DT, Chen RJ, Yang LY, Ho TJ, Kao HC. Edible folic acid and medicinal folinic acid produce cardioprotective effects in late-stage triple-transgenic Alzheimer's disease model mice by suppressing cardiac hypertrophy and fibrosis. ENVIRONMENTAL TOXICOLOGY 2022; 37:1740-1749. [PMID: 35286012 DOI: 10.1002/tox.23521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/15/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
Some clinical studies have indicated the patients with Alzheimer's disease (AD) display an increased risk of cardiovascular disease (CVD). Here, to examine the relationship between AD and CVDs, we investigated the changes in heart function in triple-transgenic late-stage AD model mice (3× Tg-AD; APPSwe, PS1M146V, and tauP301L). We fed the AD mice folic acid (FA) or folinic acid (FN) and analyzed the protective effects of the compounds on the heart; specifically, 20-month-old triple-transgenic AD mice, weighing 34-55 g, were randomly allocated into three groups-the AD, AD + FA, and AD + FN groups-and subject to gastric feeding with FA or FN once daily at 12 mg/kg body weight (BW) for 3 months. Mouse BWs were assessed throughout the trial, at the end of which the animals were sacrificed using carbon dioxide suffocation. We found that BW, whole-heart weight, and left-ventricle weight were reduced in the AD + FA and AD + FN groups as compared with the measurements in the AD group. Furthermore, western blotting of excised heart tissue revealed that the levels of the hypertrophy-related protein markers phospho(p)-p38 and p-c-Jun were markedly decreased in the AD + FA group, whereas p-GATA4, and ANP were strongly reduced in the AD + FN group. Moreover, the fibrosis-related proteins uPA, MMP-2, MEK1/2 and SP-1 were decreased in the heart in both AD + FN group. In summary, our results indicate that FA and FN can exert anti-cardiac hypertrophy and fibrosis effects to protect the heart in aged triple-transgenic AD model mice, particular in FN.
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Affiliation(s)
- Chih-Yang Huang
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
- Department of Biotechnology, Asia University, Taichung, Taiwan
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
- Center of General Education, Buddhist Tzu Chi Medical Foundation, Tzu Chi University of Science and Technology, Hualien, Taiwan
| | - Yi-Chen Su
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Cheng-You Lu
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | | | | | - Da-Tong Ju
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ray-Jade Chen
- Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
- Laboratory for Neural Repair, China Medical University Hospital, Taichung, Taiwan
| | - Tsung-Jung Ho
- Integration Center of Traditional Chinese and Modern Medicine, HualienTzu Chi Hospital, Hualien, Taiwan
- Department of Chinese Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien, Taiwan
- School of Post-Baccalaure-ate Chinese Medicine, College of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Hui-Chuan Kao
- Department of Public Health, Tzu Chi University, Hualien, Taiwan
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2
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Selmin OI, Donovan MG, Stillwater BJ, Neumayer L, Romagnolo DF. Epigenetic Regulation and Dietary Control of Triple Negative Breast Cancer. Front Nutr 2020; 7:159. [PMID: 33015128 PMCID: PMC7506147 DOI: 10.3389/fnut.2020.00159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022] Open
Abstract
Triple negative breast cancer (TNBC) represents a highly heterogeneous group of breast cancers, lacking expression of the estrogen (ER) and progesterone (PR) receptors, and human epidermal growth factor receptor 2 (HER2). TNBC are characterized by a high level of mutation and metastasis, poor clinical outcomes and overall survival. Here, we review the epigenetic mechanisms of regulation involved in cell pathways disrupted in TNBC, with particular emphasis on dietary food components that may be exploited for the development of effective strategies for management of TNBC.
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Affiliation(s)
- Ornella I Selmin
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ, United States.,University of Arizona Cancer Center, The University of Arizona, Tucson, AZ, United States
| | - Micah G Donovan
- University of Arizona Cancer Center, The University of Arizona, Tucson, AZ, United States
| | - Barbara J Stillwater
- Department of Surgery, Breast Surgery Oncology, The University of Arizona, Tucson, AZ, United States
| | - Leigh Neumayer
- Department of Surgery, Breast Surgery Oncology, The University of Arizona, Tucson, AZ, United States
| | - Donato F Romagnolo
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ, United States.,University of Arizona Cancer Center, The University of Arizona, Tucson, AZ, United States
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3
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Kovács T, Szabó-Meleg E, Ábrahám IM. Estradiol-Induced Epigenetically Mediated Mechanisms and Regulation of Gene Expression. Int J Mol Sci 2020; 21:ijms21093177. [PMID: 32365920 PMCID: PMC7246826 DOI: 10.3390/ijms21093177] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 12/20/2022] Open
Abstract
Gonadal hormone 17β-estradiol (E2) and its receptors are key regulators of gene transcription by binding to estrogen responsive elements in the genome. Besides the classical genomic action, E2 regulates gene transcription via the modification of epigenetic marks on DNA and histone proteins. Depending on the reaction partner, liganded estrogen receptor (ER) promotes DNA methylation at the promoter or enhancer regions. In addition, ERs are important regulators of passive and active DNA demethylation. Furthermore, ERs cooperating with different histone modifying enzymes and chromatin remodeling complexes alter gene transcription. In this review, we survey the basic mechanisms and interactions between estrogen receptors and DNA methylation, demethylation and histone modification processes as well as chromatin remodeling complexes. The particular relevance of these mechanisms to physiological processes in memory formation, embryonic development, spermatogenesis and aging as well as in pathophysiological changes in carcinogenesis is also discussed.
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Affiliation(s)
- Tamás Kovács
- Molecular Neuroendocrinology Research Group, Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Center, University of Pécs, H-7624 Pécs, Hungary;
| | - Edina Szabó-Meleg
- Department of Biophysics, Medical School, University of Pécs, H-7624 Pécs, Hungary;
| | - István M. Ábrahám
- Molecular Neuroendocrinology Research Group, Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Center, University of Pécs, H-7624 Pécs, Hungary;
- Correspondence:
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4
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Wilson AJ, Stubbs M, Liu P, Ruggeri B, Khabele D. The BET inhibitor INCB054329 reduces homologous recombination efficiency and augments PARP inhibitor activity in ovarian cancer. Gynecol Oncol 2018; 149:575-584. [PMID: 29567272 DOI: 10.1016/j.ygyno.2018.03.049] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Homologous recombination (HR)-proficient ovarian tumors have poorer clinical outcomes and show resistance to poly ADP ribose polymerase inhibitors (PARPi). A subset of HR-proficient ovarian tumors show amplification in bromodomain and extra-terminal (BET) genes such as BRD4. We aimed to test the hypothesis that BRD4 inhibition sensitizes ovarian cancer cells to PARPi by reducing HR efficiency and increasing DNA damage. METHODS HR-proficient ovarian cancer cell lines (OVCAR-3, OVCAR-4, SKOV-3, UWB1.289+BRCA1) were treated with BRD4-targeting siRNA, novel (INB054329, INCB057643) and established (JQ1) BET inhibitors (BETi) and PARPi (olaparib, rucaparib). Cell growth and viability were assessed by sulforhodamine B assays in vitro, and in SKOV-3 and ovarian cancer patient-derived xenografts in vivo. DNA damage and repair (pH2AX, RAD51 and BRCA1 foci formation, and DRGFP HR reporter activity), apoptosis markers (cleaved PARP, cleaved caspase-3, Bax) and proliferation markers (PCNA, Ki67) were assessed by immunofluorescence and western blot. RESULTS In cultured cells, inhibition of BRD4 by siRNA or INCB054329 reduced expression and function of BRCA1 and RAD51, reduced HR reporter activity, and sensitized the cells to olaparib-induced growth inhibition, DNA damage induction and apoptosis. Synergy was observed between all BETi tested and PARPi. INCB054329 and olaparib also co-operatively inhibited xenograft tumor growth, accompanied by reduced BRCA1 expression and proliferation, and increased apoptosis and DNA damage. CONCLUSIONS These results provide strong rationale for using BETi to extend therapeutic efficacy of PARPi to HR-proficient ovarian tumors and could benefit a substantial number of women diagnosed with this devastating disease.
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Affiliation(s)
- Andrew J Wilson
- Department of Obstetrics & Gynecology, Vanderbilt University Medical Center, Nashville, TN, United States; Vanderbilt-Ingram Cancer Center, Nashville, TN, United States
| | | | - Phillip Liu
- Incyte Corporation, Wilmington, DE, United States
| | | | - Dineo Khabele
- The University of Kansas Medical Center, Kansas City, KS, United States; The University of Kansas Cancer Center, Kansas City, KS, United States.
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Jabareen A, Abu-Jaafar A, Abou-Kandil A, Huleihel M. Effect of TPA and HTLV-1 Tax on BRCA1 and ERE controlled genes expression. Cell Cycle 2017; 16:1336-1344. [PMID: 28594273 DOI: 10.1080/15384101.2017.1327491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Interference with the expression and/or functions of the multifunctional tumor suppressor BRCA1 leads to a high risk of breast and ovarian cancers. BRCA1 expression is usually activated by the estrogen (E2) liganded ERα receptor. Activated ERα is considered as a potent transcription factor which activates various genes expression by 2 pathways. A classical pathway, ERα binds directly to E2-responsive elements (EREs) in the promoters of the responsive genes and a non-classical pathway where ERα indirectly binds with the appropriate gene promoter. In our previous study, HTLV-1Tax was found to strongly inhibit ERα induced BRCA1 expression while stimulating ERα induced ERE dependent genes. TPA is a strong PKC activator which found to induce the expression of HTLV-1. Here we examined the effect of TPA on the expression of BRCA1 and genes controlled by ERE region in MCF-7 cells and on Tax activity on these genes. Our results showed strong stimulatory effect of TPA on both BRCA1 and ERE expression without treatment with E2. Tax did not show any significant effect on these TPA activities. It seems that TPA activation of BRCA1 and ERE expression is dependent on PKC activity but not through the NFκB pathway. However, 53BP1 may be involved in this TPA activity because its overexpression significantly reduced the TPA stimulatory effect on BRCA1 and ERE expression. Additionally, our Chip assay results probably exclude possible involvement of ERα pathway in this TPA activity because TPA did not interfere with the binding of ERα to both BRCA1 promoter and ERE region.
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Affiliation(s)
- Azhar Jabareen
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Aya Abu-Jaafar
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Ammar Abou-Kandil
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Mahmoud Huleihel
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
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6
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Romagnolo DF, Donovan MG, Papoutsis AJ, Doetschman TC, Selmin OI. Genistein Prevents BRCA1 CpG Methylation and Proliferation in Human Breast Cancer Cells with Activated Aromatic Hydrocarbon Receptor. Curr Dev Nutr 2017; 1:e000562. [PMID: 29955703 PMCID: PMC5998349 DOI: 10.3945/cdn.117.000562] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/02/2017] [Accepted: 05/19/2017] [Indexed: 01/11/2023] Open
Abstract
Background: Previous studies have suggested a causative role for agonists of the aromatic hydrocarbon receptor (AhR) in the etiology of breast cancer 1, early-onset (BRCA-1)-silenced breast tumors, for which prospects for treatment remain poor. Objectives: We investigated the regulation of BRCA1 by the soy isoflavone genistein (GEN) in human estrogen receptor α (ERα)-positive Michigan Cancer Foundation-7 (MCF-7) and ERα-negative sporadic University of Arizona Cell Culture-3199 (UACC-3199) breast cancer cells, respectively, with inducible and constitutively active AhR. Methods: In MCF-7 cells, we analyzed the dose- and time-dependent effects of GEN and (-)-epigallocatechin-3-gallate (EGCG) control, selected as prototype dietary DNA methyltransferase (DNMT) inhibitors, on BRCA-1 expression after AhR activation with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and in TCDD-washout experiments. We compared the effects of GEN and EGCG on BRCA1 cytosine-phosphate-guanine (CpG) methylation and cell proliferation. Controls for DNA methylation and proliferation were changes in expression of DNMT-1, cyclin D1, and p53, respectively. In UACC-3199 cells, we compared the effects of GEN and α-naphthoflavone (αNF; 7,8-benzoflavone), a synthetic flavone and AhR antagonist, on BRCA1 expression and CpG methylation, cyclin D1, and cell growth. Finally, we examined the effects of GEN and αNF on BRCA1, AhR-inducible cytochrome P450 (CYP)-1A1 (CYP1A1) and CYP1B1, and AhR mRNA expression. Results: In MCF-7 cells, GEN exerted dose- and time-dependent preventative effects against TCDD-dependent downregulation of BRCA-1. After TCDD washout, GEN rescued BRCA-1 protein expression while reducing DNMT-1 and cyclin D1. GEN and EGCG reduced BRCA1 CpG methylation and cell proliferation associated with increased p53. In UACC-3199 cells, GEN reduced BRCA1 and estrogen receptor-1 (ESR1) CpG methylation, cyclin D1, and cell growth while inducing BRCA-1 and CYP1A1. Conclusions: Results suggest preventative effects for GEN and EGCG against BRCA1 CpG methylation and downregulation in ERα-positive breast cancer cells with activated AhR. GEN and flavone antagonists of AhR may be useful for reactivation of BRCA1 and ERα via CpG demethylation in ERα-negative breast cancer cells harboring constitutively active AhR.
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Affiliation(s)
- Donato F Romagnolo
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ
- Department of The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ
| | - Micah G Donovan
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ
- Department of The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ
| | - Andreas J Papoutsis
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ
- Department of The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ
| | - Tom C Doetschman
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ
- Department of The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ
| | - Ornella I Selmin
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ
- Department of The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ
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7
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A transgenic mouse model expressing an ERα folding biosensor reveals the effects of Bisphenol A on estrogen receptor signaling. Sci Rep 2016; 6:34788. [PMID: 27721470 PMCID: PMC5056407 DOI: 10.1038/srep34788] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/20/2016] [Indexed: 02/07/2023] Open
Abstract
Estrogen receptor-α (ERα) plays an important role in normal and abnormal physiology of the human reproductive system by interacting with the endogenous ligand estradiol (E2). However, other ligands, either analogous or dissimilar to E2, also bind to ERα. This may create unintentional activation of ER signaling in reproductive tissues that can lead to cancer development. We developed a transgenic mouse model that constitutively expresses a firefly luciferase (FLuc) split reporter complementation biosensor (NFLuc-ER-LBDG521T-CFLuc) to simultaneously evaluate the dynamics and potency of ligands that bind to ERα. We first validated this model using various ER ligands, including Raloxifene, Diethylstilbestrol, E2, and 4-hydroxytamoxifen, by employing FLuc-based optical bioluminescence imaging of living mice. We then used the model to investigate the carcinogenic property of Bisphenol A (BPA), an environmental estrogen, by long-term exposure at full and half environmental doses. We showed significant carcinogenic effects on female animals while revealing activated downstream ER signaling as measured by bioluminescence imaging. BPA induced tumor-like outgrowths in female transgenic mice, histopathologically confirmed to be neoplastic and epithelial in origin. This transgenic mouse model expressing an ERα folding-biosensor is useful in evaluation of estrogenic ligands and their downstream effects, and in studying environmental estrogen induced carcinogenesis in vivo.
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8
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Abou-Kandil A, Eisa N, Jabareen A, Huleihel M. Differential effects of HTLV-1 Tax oncoprotein on the different estrogen-induced-ER α-mediated transcriptional activities. Cell Cycle 2016; 15:2626-2635. [PMID: 27420286 PMCID: PMC5053584 DOI: 10.1080/15384101.2016.1208871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/28/2016] [Accepted: 06/28/2016] [Indexed: 12/25/2022] Open
Abstract
The activated estrogen (E2) receptor α (ERα) is a potent transcription factor that is involved in the activation of various genes by 2 different pathways; a classical and non-classical. In classical pathway, ERα binds directly to E2-responsive elements (EREs) located in the appropriate genes promoters and stimulates their transcription. However, in non-classical pathway, the ERα can indirectly bind with promoters and enhance their activity. For instance, ERα activates BRCA1 expression by interacting with jun/fos complex bound to the AP-1 site in BRCA1 promoter. Interference with the expression and/or functions of BRCA1, leads to high risk of breast or/and ovarian cancer. HTLV-1Tax was found to strongly inhibit BRCA1 expression by preventing the binding of E2-ERα complex to BRCA1 promoter. Here we examined Tax effect on ERα induced activation of genes by the classical pathway by testing its influence on E2-induced expression of ERE promoter-driven luciferase reporter (ERE-Luc). Our findings showed that E2 profoundly stimulated this reporter expression and that HTLV-1Tax significantly induced this stimulation. This result is highly interesting because in our previous study Tax was found to strongly block the E2-ERα-mediated activation of BRCA1 expression. ERα was found to produce a big complex by recruiting various cofactors in the nucleus before binding to the ERE region. We also found that only part of the reqruited cofactors are required for the transcriptional activity of ERα complex. Chip assay revealed that the binding of Tax to the ERα complex, did not interfere with its link to ERE region.
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Affiliation(s)
- Ammar Abou-Kandil
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Nora Eisa
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Azhar Jabareen
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Mahmoud Huleihel
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
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9
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Beishline K, Azizkhan-Clifford J. Sp1 and the 'hallmarks of cancer'. FEBS J 2015; 282:224-58. [PMID: 25393971 DOI: 10.1111/febs.13148] [Citation(s) in RCA: 369] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 09/26/2014] [Accepted: 11/10/2014] [Indexed: 12/19/2022]
Abstract
For many years, transcription factor Sp1 was viewed as a basal transcription factor and relegated to a role in the regulation of so-called housekeeping genes. Identification of Sp1's role in recruiting the general transcription machinery in the absence of a TATA box increased its importance in gene regulation, particularly in light of recent estimates that the majority of mammalian genes lack a TATA box. In this review, we briefly consider the history of Sp1, the founding member of the Sp family of transcription factors. We review the evidence suggesting that Sp1 is highly regulated by post-translational modifications that positively and negatively affect the activity of Sp1 on a wide array of genes. Sp1 is over-expressed in many cancers and is associated with poor prognosis. Targeting Sp1 in cancer treatment has been suggested; however, our review of the literature on the role of Sp1 in the regulation of genes that contribute to the 'hallmarks of cancer' illustrates the extreme complexity of Sp1 functions. Sp1 both activates and suppresses the expression of a number of essential oncogenes and tumor suppressors, as well as genes involved in essential cellular functions, including proliferation, differentiation, the DNA damage response, apoptosis, senescence and angiogenesis. Sp1 is also implicated in inflammation and genomic instability, as well as epigenetic silencing. Given the apparently opposing effects of Sp1, a more complete understanding of the function of Sp1 in cancer is required to validate its potential as a therapeutic target.
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Affiliation(s)
- Kate Beishline
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
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10
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Zhou Y, Ming J, Xu Y, Zhang Y, Jiang J. ERβ1 inhibits the migration and invasion of breast cancer cells through upregulation of E-cadherin in a Id1-dependent manner. Biochem Biophys Res Commun 2014; 457:141-7. [PMID: 25514034 DOI: 10.1016/j.bbrc.2014.12.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/08/2014] [Indexed: 02/07/2023]
Abstract
ERβ1 is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. It plays an important role in regulating the progression of breast cancer. However, the mechanisms of ERβ1 in tumorigenesis, metastasis and prognosis are still not fully clear. In this study, we showed that the expression of ERβ1 was positively correlated with E-cadherin expression in breast cancer cell lines. In addition, we found that ERβ1 upregulates E-cadherin expression in breast cancer cell lines. Furthermore, we also found that ERβ1 inhibits the migration and invasion of breast cancer cells and upregulated E-cadherin expression in a Id1-dependent manner. Taken together, our study provides further understanding of the molecular mechanism of ERβ1 in tumor metastasis and suggests the feasibility of developing novel therapeutic approaches to target Id1 to inhibit breast cancer metastasis.
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Affiliation(s)
- Yan Zhou
- Breast Disease Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jia Ming
- Department of Breast, Thyroid and Pancreas Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yan Xu
- Department of Breast and Thyroid Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yi Zhang
- Breast Disease Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
| | - Jun Jiang
- Breast Disease Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
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11
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Abstract
Breast cancer (BC) is traditionally viewed as an oestrogen-dependent disease in which the androgen receptor (AR) is inhibitory, counteracting the oncogenic activity of oestrogen receptor α (ERα (ESR1)). Most probably as a result of this crosstalk, the AR has prognostic value in ER-positive disease, with AR positivity reported to correlate with a better prognosis. Activation of the AR pathway has been previously used as a therapeutic strategy to treat BC, but its usage declined following the introduction of the anti-oestrogen tamoxifen. More recently, it has been demonstrated that a subset of triple-negative BCs (molecular apocrine) are dependent upon androgen signalling for growth and therapies that inhibit androgen signalling, currently used for the treatment of prostate cancer, e.g. the antiandrogen bicalutamide and the CYP17 inhibitor abiraterone acetate are undergoing clinical trials to investigate their efficacy in this BC subtype. This review summarises the current knowledge of AR activity in BC.
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Affiliation(s)
- F M Fioretti
- Androgen Signalling LaboratoryDepartment of Surgery and Cancer, Imperial College London, London W12 0NN, UKMolecular OncologySchool of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UK
| | - A Sita-Lumsden
- Androgen Signalling LaboratoryDepartment of Surgery and Cancer, Imperial College London, London W12 0NN, UKMolecular OncologySchool of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UK
| | - C L Bevan
- Androgen Signalling LaboratoryDepartment of Surgery and Cancer, Imperial College London, London W12 0NN, UKMolecular OncologySchool of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UK
| | - G N Brooke
- Androgen Signalling LaboratoryDepartment of Surgery and Cancer, Imperial College London, London W12 0NN, UKMolecular OncologySchool of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UKAndrogen Signalling LaboratoryDepartment of Surgery and Cancer, Imperial College London, London W12 0NN, UKMolecular OncologySchool of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UK
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12
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Shukrun M, Jabareen A, Abou-Kandil A, Chamias R, Aboud M, Huleihel M. HTLV-1 Tax oncoprotein inhibits the estrogen-induced-ER α-Mediated BRCA1 expression by interaction with CBP/p300 cofactors. PLoS One 2014; 9:e89390. [PMID: 24586743 PMCID: PMC3931753 DOI: 10.1371/journal.pone.0089390] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/21/2014] [Indexed: 02/06/2023] Open
Abstract
BRCA1 is a multifunctional tumor suppressor, whose expression is activated by the estrogen (E2)-liganded ERα receptor and regulated by certain recruited transcriptional co-activators. Interference with BRCA1 expression and/or functions leads to high risk of breast or/and ovarian cancer. Another multifunctional protein, HTLV-1Tax oncoprotein, is widely regarded as crucial for developing adult T-cell leukemia and other clinical disorders. Tax profile reveals that it can antagonize BRCA1 expression and/or functionality. Therefore, we hypothesize that Tax expression in breast cells can sensitize them to malignant transformation by environmental carcinogens. Here we examined Tax effect on BRCA1 expression by testing its influence on E2-induced expression of BRCA1 promoter-driven luciferase reporter (BRCA1-Luc). We found that E2 strongly stimulated this reporter expression by liganding to ERα, which consequently associated with BRCA1 promoter, while ERα concomitantly recruited CBP/p300 to this complex for co-operative enhancement of BRCA1 expression. Introducing Tax into these cells strongly blocked this E2-ERα-mediated activation of BRCA1 expression. We noted, also, that Tax exerted this inhibition by binding to CBP/p300 without releasing them from their complex with ERα. Chip assay revealed that the binding of Tax to the CBP/p300-ERα complex, prevented its link to AP1 site. Interestingly, we noted that elevating the intracellular pool of CBP or p300 to excessive levels dramatically reduced the Tax-mediated inhibition of BRCA1 expression. Exploring the mechanism of this reduction revealed that the excessive co-factors were sufficient to bind separately the free Tax molecules, thus lowering their amount in the CBP/p300-ERα complex and relieving, thereby, the inhibition of BRCA1 expression.
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Affiliation(s)
- Meital Shukrun
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Azhar Jabareen
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ammar Abou-Kandil
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Rachel Chamias
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Mordechai Aboud
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Mahmoud Huleihel
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
- * E-mail:
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Influence of estrogen and variations at the BRCA1 promoter region on transcription and translation. Mol Biol Rep 2013; 41:489-95. [PMID: 24293149 DOI: 10.1007/s11033-013-2884-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 11/23/2013] [Indexed: 12/20/2022]
Abstract
We analyzed wild-type (WT) and four sequence variants of the BRCA1 promoter region-found in patients selected for hereditary breast and ovarian cancer syndrome-in respect to their influence on transcription and translation efficiencies in transient transfection assays in the presence or absence of estrogen. Five types of plasmids containing the EGFP reporter gene proceeded by WT 5'UTR-a, WT 5'UTR-b, and the three 5'UTR-b variants were constructed to evaluate their influence on translation. Plasmids containing the firefly luciferase reporter gene were constructed with the WT BRCA1 promoter region (containing promoter α, 5'UTR-a, promoter β, and 5'UTR-b) and with the four promoter variants for evaluating their influence on transcription and translation. All constructs were transfected in MCF7 cells maintained with and without estrogen. Expression of EGFP plasmids with WT 5'UTR-a was six to sevenfold higher than of plasmids with WT 5'UTR-b, expression of WT and the three variant 5'UTR-b plasmids showed slight differences in EGFP expression, and the presence or absence of estrogen result in non-significant changes in expression. Promoter's constructs that carry the variants WT or g.3988C showed a higher firefly luciferase activity when estrogen is present; conversely, no significant differences were found in the transcription efficiency of the reporter gene indicating that estrogen affect the translation rather than transcription. The presence or absence of estrogen did not affect the activity of firefly luciferase for constructs with the other promoter variants, being the transcription efficiencies equivalent in both conditions.
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Yang P, Zhang Y, Pang J, Zhang S, Yu Q, He L, Wagner KU, Zhou Z, Wang CY. Loss of Jak2 impairs endothelial function by attenuating Raf-1/MEK1/Sp-1 signaling along with altered eNOS activities. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:617-25. [PMID: 23747947 DOI: 10.1016/j.ajpath.2013.04.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 02/17/2013] [Accepted: 04/08/2013] [Indexed: 10/26/2022]
Abstract
A number of inhibitors have been used to dissect the functional relevance of Jak2 in endothelial homeostasis, with disparate results. Given that Jak2 deficiency leads to embryonic lethality, the exact role of Jak2 in the regulation of postnatal endothelial function is yet to be fully elucidated. We generated a model in which Jak2 deficiency can be induced by tamoxifen in adult mice. Loss of Jak2 significantly impaired endothelium-dependent response capacity for vasodilators. Matrigel plug assays indicated a notable decrease in endothelial angiogenic function in Jak2-deficient mice. Studies in a hindlimb ischemic model indicated that Jak2 activity is likely to be a prerequisite for prompt perfusion recovery, based on the concordance of temporal changes in Jak2 expression during the course of ischemic injury and perfusion recovery. A remarkable delay in perfusion recovery, along with reduced capillary and arteriole formation, was observed in Jak2-deficient mice. Antibody array studies indicated that loss of Jak2 led to repressed eNOS expression. In mechanistic studies, Jak2 deficiency attenuated Raf-1/MEK1 signaling, which then reduced activity of Sp-1, an essential transcription factor responsible for eNOS expression. These data are important not only for understanding the exact role that Jak2 plays in endothelial homeostasis, but also for assessing Jak2-based therapeutic strategies in a variety of clinical settings.
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Affiliation(s)
- Ping Yang
- Center for Biomedical Research, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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16
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Wang Q, Li J, Yang X, Sun H, Gao S, Zhu H, Wu J, Jin W. Nrf2 is associated with the regulation of basal transcription activity of the BRCA1 gene. Acta Biochim Biophys Sin (Shanghai) 2013; 45:179-87. [PMID: 23353771 DOI: 10.1093/abbs/gmt001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BRCA1 is closely related to the pathogenesis of breast cancer. The activity of BRCA1 promoter is regulated by transcriptional factors. The transcription factor Nrf2 (Nuclear factor-erythroid-2p45-related factor 2) is a potent transcriptional activator and plays a central role in inducible expression of many cytoprotective genes. In this report, we found that over-expression of Nrf2 stimulated BRCA1 expression, knockdown of Nrf2 attenuated BRCA1 expression. Nrf2 also interacted with CBP and p300 to form an active transcription complex, which could bind to the ARE (antioxidant response element) site on the BRCA1 promoter and activate its transcription by inducing histone acetylation. Our finding could lead to a better understanding of the development of breast cancer.
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Affiliation(s)
- Qiaoqiao Wang
- Department of Oncology, Department of Breast Surgery, Breast Cancer Institute, Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai 200032, China
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Shan J, Dsouza SP, Bakhru S, Al-Azwani EK, Ascierto ML, Sastry KS, Bedri S, Kizhakayil D, Aigha II, Malek J, Al-Bozom I, Gehani S, Furtado S, Mathiowitz E, Wang E, Marincola FM, Chouchane L. TNRC9 downregulates BRCA1 expression and promotes breast cancer aggressiveness. Cancer Res 2013; 73:2840-9. [PMID: 23447579 DOI: 10.1158/0008-5472.can-12-4313] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the linkage between germline mutations of BRCA1 and hereditary breast/ovarian cancers is well established, recent evidence suggests that altered expression of wild-type BRCA1 might contribute to the sporadic forms of breast cancer. The breast cancer gene trinucleotide-repeat-containing 9 (TNRC9; TOX3) has been associated with disease susceptibility but its function is undetermined. Here, we report that TNRC9 is often amplified and overexpressed in breast cancer, particularly in advanced breast cancer. Gene amplification was associated with reduced disease-free and metastasis-free survival rates. Ectopic expression of TNRC9 increased breast cancer cell proliferation, migration, and survival after exposure to apoptotic stimuli. These phenotypes were associated with tumor progression in a mouse model of breast cancer. Gene expression profiling, protein analysis, and in silico assays of large datasets of breast and ovarian cancer samples suggested that TNRC9 and BRCA1 expression were inversely correlated. Notably, we found that TNRC9 bound to both the BRCA1 promoter and the cAMP-responsive element-binding protein (CREB) complex, a regulator of BRCA1 transcription. In support of this connection, expression of TNRC9 downregulated expression of BRCA1 by altering the methylation status of its promoter. Our studies unveil a function for TNRC9 in breast cancer that highlights a new paradigm in BRCA1 regulation.
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Affiliation(s)
- Jingxuan Shan
- Laboratory of Genetic Medicine and Immunology, Weill Cornell Medical College in Qatar-Qatar Foundation, Qatar
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Hervouet E, Cartron PF, Jouvenot M, Delage-Mourroux R. Epigenetic regulation of estrogen signaling in breast cancer. Epigenetics 2013; 8:237-45. [PMID: 23364277 PMCID: PMC3669116 DOI: 10.4161/epi.23790] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Estrogen signaling is mediated by ERα and ERβ in hormone dependent, breast cancer (BC). Over the last decade the implication of epigenetic pathways in BC tumorigenesis has emerged: cancer-related epigenetic modifications are implicated in both gene expression regulation, and chromosomal instability. In this review, the epigenetic-mediated estrogen signaling, controlling both ER level and ER-targeted gene expression in BC, are discussed: (1) ER silencing is frequently observed in BC and is often associated with epigenetic regulations while chemical epigenetic modulators restore ER expression and increase response to treatment;(2) ER-targeted gene expression is tightly regulated by co-recruitment of ER and both coactivators/corepressors including HATs, HDACs, HMTs, Dnmts and Polycomb proteins.
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Affiliation(s)
- Eric Hervouet
- Université de Franche-Comté, Laboratoire de Biochimie, EA3922, Expression Génique et Pathologies du Système Nerveux Central, SFRIBCT FED 4234, UFR Sciences et Techniques, Besançon, France.
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Papoutsis AJ, Borg JL, Selmin OI, Romagnolo DF. BRCA-1 promoter hypermethylation and silencing induced by the aromatic hydrocarbon receptor-ligand TCDD are prevented by resveratrol in MCF-7 cells. J Nutr Biochem 2011; 23:1324-32. [PMID: 22197621 DOI: 10.1016/j.jnutbio.2011.08.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 07/17/2011] [Accepted: 08/03/2011] [Indexed: 01/26/2023]
Abstract
Epigenetic mechanisms may contribute to reduced expression of the tumor suppressor gene BRCA-1 in sporadic breast cancers. Through environmental exposure and diet, humans are exposed to xenobiotics and food compounds that bind the aromatic hydrocarbon receptor (AhR). AhR-ligands include the dioxin-like and tumor promoter 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). The activated AhR regulates transcription through binding to xenobiotic response elements (XREs=GCGTG) and interactions with transcription cofactors. Previously, we reported on the presence of several XREs in the proximal BRCA-1 promoter and that the expression of endogenous AhR was required for silencing of BRCA-1 expression by TCDD. Here, we document that in estrogen receptor-α-positive and BRCA-1 wild-type MCF-7 breast cancer cells, the treatment with TCDD attenuated 17β-estradiol-dependent stimulation of BRCA-1 protein and induced hypermethylation of a CpG island spanning the BRCA-1 transcriptional start site of exon-1a. Additionally, we found that TCDD enhanced the association of the AhR; DNA methyl transferase (DNMT)1, DNMT3a and DNMT3b; methyl binding protein (MBD)2; and trimethylated H3K9 (H3K9me3) with the BRCA-1 promoter. Conversely, the phytoalexin resveratrol, selected as a prototype dietary AhR antagonist, antagonized at physiologically relevant doses (1 μmol/L) the TCDD-induced repression of BRCA-1 protein, BRCA-1 promoter methylation and the recruitment of the AhR, MBD2, H3K9me3 and DNMTs (1, 3a and 3b). Taken together, these observations provide mechanistic evidence for AhR agonists in the establishment of BRCA-1 promoter hypermethylation and the basis for the development of prevention strategies based on AhR antagonists.
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Affiliation(s)
- Andreas J Papoutsis
- Department of Nutritional Sciences, The University of Arizona, Tucson, AZ 85721, USA
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Corkery D, Thillainadesan G, Coughlan N, Mohan RD, Isovic M, Tini M, Torchia J. Regulation of the BRCA1 gene by an SRC3/53BP1 complex. BMC BIOCHEMISTRY 2011; 12:50. [PMID: 21914189 PMCID: PMC3180649 DOI: 10.1186/1471-2091-12-50] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 09/13/2011] [Indexed: 11/10/2022]
Abstract
Background Steroid Receptor coactivator 3(SRC3) is an oncogene and a member of the SRC family of nuclear receptor coactivator proteins that mediate the transcriptional effects of nuclear hormone receptors as well as other transcription factors. Results We have used protein purification and mass spectrometry to identify the 53BP1 tumour suppressor as a novel SRC3-associated protein. Copurification was demonstrated using multiple antibodies, and was not dependent on DNA damage suggesting that SRC3 is not directly involved in the DNA damage response. However using chromatin immunoprecipitation(ChIP) and siRNA knockdown, we have demonstrated that both SRC3 and 53BP1 co-occupy the same region of the BRCA1 promoter and both are required for BRCA1 expression in HeLa cells. Conclusions Our results suggest that both 53BP1 and SRC3 have a common function that converge at the BRCA1 promoter and possibly other genes important for DNA repair and genomic stability.
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Affiliation(s)
- Dale Corkery
- Department of Oncology, London Regional Cancer Program and Lawson Health Research Institute, 790 Commissioners Rd, London, Ontario N6A 4L6 Canada
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Heyn H, Engelmann M, Schreek S, Ahrens P, Lehmann U, Kreipe H, Schlegelberger B, Beger C. MicroRNA miR-335 is crucial for the BRCA1 regulatory cascade in breast cancer development. Int J Cancer 2011; 129:2797-806. [PMID: 21618216 DOI: 10.1002/ijc.25962] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 12/27/2010] [Indexed: 01/16/2023]
Abstract
The expression of microRNAs is altered in various cancer types, leading to their definition as onco- and tumor-suppressor microRNAs. In our study, we investigated the role of miR-335 in the formation of sporadic human breast cancer and its involvement in the regulatory network of the breast cancer susceptibility gene BRCA1. To validate single components of the BRCA1 cascade, microRNA overexpression was performed in a cell culture model with subsequent protein analysis and luciferase reporter assays. Here, we were able to identify miR-335 as simultaneously regulating the known BRCA1 activators ERα, IGF1R, SP1 and the repressor ID4, including a feedback regulation of miR-335 expression by estrogens. Overexpression of miR-335 resulted in an upregulation of BRCA1 mRNA expression, suggesting a functional dominance of ID4 signaling. The relevance of the miR-335 regulation for human breast cancer was confirmed in primary sporadic breast cancer specimens with significantly decreased miR-335 levels (p < 0.05) in comparison to normal controls. Interestingly, the microRNA expression level correlated positively to the BRCA1 transcript level, supporting the hypothesis of a miR-335-mediated regulation of the tumor suppressor gene. Functionally, overexpression of miR-335 led to decreased cell viability and an increase in apoptosis, supporting its tumor-suppressive function. In summary, our data indicate that miR-335 affects different targets in the upstream BRCA1-regulatory cascade with impact on key cellular functions such as proliferation and apoptosis. Deregulation of the microRNA during breast cancer development and progression may thereby lead to an increased tumorigenic potential by inactivating crucial tumor-suppressive signals.
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Affiliation(s)
- Holger Heyn
- Institute of Cell and Molecular Pathology, Hannover Medical School, Hannover, Germany
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Dateki M, Kunitomo M, Yoshioka K, Yanai K, Nakasono S, Negishi T. Adaptive gene regulation of pyruvate dehydrogenase kinase isoenzyme 4 in hepatotoxic chemical-induced liver injury and its stimulatory potential for DNA repair and cell proliferation. J Recept Signal Transduct Res 2011; 31:85-95. [PMID: 21182459 DOI: 10.3109/10799893.2010.538405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The processes involved in the adaptation of animals to environmental factors remain unclear. We examined the mechanisms underlying the adaptive potential of the mouse against hepatotoxic chemical-induced injury. Microarray analysis revealed that ethylbenzene, a hepatotoxic chemical, upregulated PDK4 (encoding pyruvate dehydrogenase kinase isoenzyme 4) in mouse livers and that the upregulation was enhanced by previous exposure to the chemical. Although PDK4 is an energy resource regulator induced by starvation, expression of other fasting-inducible genes was unaffected. PDK4 induced by chemical stress developed hepatic accumulation of sirtuin 1 by regulating pyruvate concentration and activated the Nbn and ATM, which are critical for DNA repair and checkpoint activation. PDK4 overexpression on carbon tetrachloride (CCl(4))-induced liver injury resulted in delayed necrotic tissue recovery with cell cycle arrest and decreased γH2AX foci and micronucleus formation. PDK4 silencing on CCl(4)-induced liver injury accelerated necrotic tissue recovery and increased γH2AX foci and micronucleus formation, indicating the essential role of PDK4 in DNA repair and checkpoint activation. PDK4 overexpression induced pancreas-specific transcription factor 1a (Ptf1a) upregulation and transcriptional activation of several pancreatic genes in the liver. Ptf1a overexpression by adenoviral gene delivery resulted in accelerated tissue recovery on CCl(4)-induced liver injury. Our data identified PDK4 as a novel pivotal factor in adaptation to chemical stress.
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Affiliation(s)
- Minori Dateki
- Environmental Science Laboratory, Central Research Institute of Electric Power Industry, Abiko, Chiba, Japan.
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Zhang Y, Li C, Li W, Zhao Y. Estrogen regulation of human with-no-lysine (K) kinase-4 gene expression involves AP-1 transcription factor. Mol Cell Endocrinol 2011; 332:140-8. [PMID: 20943203 DOI: 10.1016/j.mce.2010.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 09/14/2010] [Accepted: 10/05/2010] [Indexed: 10/19/2022]
Abstract
With-no-lysine (K) kinase-4 (WNK4) is a serine/threonine protein kinase and plays a crucial role in the regulation of blood pressure and electrolyte homeostasis. Whether or not estrogen, an important regulator of physiologic functions, modulates human WNK4 (hWNK4) gene expression is unknown. In the current study, real-time PCR assay showed that 17β-estradiol (E(2)) with estrogen receptor alpha (ERα) suppressed the level of hWNK4 mRNA in cultured human embryo kidney 293 cells (HEK293). Luciferase activity analysis of the truncated hWNK4 promoters indicated that a regulatory region from -216 to -202 is essential for the basal transcriptional activity and response to E(2)/ERα. Using an electrophoresis mobility shift assay and a chromatin immunoprecipitation assay, we identified an activator protein-1 (AP-1) element at position -215/-205, to which AP-1 binding was enhanced by E(2)/ERα. Accordingly, AP-1 protein was increased by E(2)/ERα using Western blot analysis. Moreover, re-chromatin-immunoprecipitation and co-immunoprecipitation assays showed a direct interaction between ERα and AP-1 in HEK293 cells. In summary, these data document that E(2)/ERα regulates hWNK4 expression partly through AP-1 binding to the hWNK4 promoter.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Medical Genetics, China Medical University, Shenyang, Liaoning, China
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Di LJ, Fernandez AG, De Siervi A, Longo DL, Gardner K. Transcriptional regulation of BRCA1 expression by a metabolic switch. Nat Struct Mol Biol 2010; 17:1406-13. [PMID: 21102443 PMCID: PMC3460552 DOI: 10.1038/nsmb.1941] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 09/16/2010] [Indexed: 12/29/2022]
Abstract
Though the linkages between germline mutations of BRCA1 and hereditary breast cancer are well known, recent evidence suggests that altered BRCA1 transcription may also contribute to sporadic forms of breast cancer. Here we show that BRCA1 expression is controlled by a dynamic equilibrium between transcriptional coactivators and co-repressors that govern histone acetylation and DNA accessibility at the BRCA1 promoter. Eviction of the transcriptional co-repressor and metabolic sensor, C terminal-binding protein (CtBP), has a central role in this regulation. Loss of CtBP from the BRCA1 promoter through estrogen induction, depletion by RNA interference or increased NAD+/NADH ratio leads to HDAC1 dismissal, elevated histone acetylation and increased BRCA1 transcription. The active control of chromatin marks, DNA accessibility and gene expression at the BRCA1 promoter by this 'metabolic switch' provides an important molecular link between caloric intake and tumor suppressor expression in mammary cells.
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Affiliation(s)
- Li-Jun Di
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, Maryland, USA
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Jin W, Liu Y, Chen L, Zhu H, Di GH, Ling H, Wu J, Shao ZM. Involvement of MyoD and c-myb in regulation of basal and estrogen-induced transcription activity of the BRCA1 gene. Breast Cancer Res Treat 2010; 125:699-713. [PMID: 20364308 DOI: 10.1007/s10549-010-0876-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 03/25/2010] [Indexed: 01/12/2023]
Abstract
BRCA1 is closely related to the pathogenesis of breast cancer, BRCA1 mRNA is reduced in sporadic breast cancer cells despite the lack of mutations. In the present report, we find that MyoD expression and BRCA1 expression is correlated in sporadic breast tumors, overexpression of MyoD and c-myb stimulates BRCA1 expression, knockdown of MyoD and c-myb attenuates BRCA1 expression and attenuates the ability of BRCA1 to protect cells against hydrogen peroxide. MyoD and c-myb interact with p300 and PCAF, forming activating transcriptional complexes which bind to E-box and c-myb sites on the BRCA1 promoter and activate its transcription by inducing histone acetylation. Regulation of BRCA1 expression by MyoD and c-myb complexes may be part of an integral signaling pathway that determines and explains breast cancer susceptibility. Detection expression status of the various proteins in these complexes may predispose to the onset of sporadic breast cancer.
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Affiliation(s)
- Wei Jin
- Department of Breast Surgery, Breast Cancer Institute, Cancer Hospital/Cancer Institute, Department of Oncology, Shanghai Medical College, Fudan University, 270 Dong An Road Road, Shanghai, 200032, People's Republic of China
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Yang R, Schlehe B, Hemminki K, Sutter C, Bugert P, Wappenschmidt B, Volkmann J, Varon R, Weber BHF, Niederacher D, Arnold N, Meindl A, Bartram CR, Schmutzler RK, Burwinkel B. A genetic variant in the pre-miR-27a oncogene is associated with a reduced familial breast cancer risk. Breast Cancer Res Treat 2009; 121:693-702. [PMID: 19921425 DOI: 10.1007/s10549-009-0633-5] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 10/30/2009] [Indexed: 12/17/2022]
Abstract
MicroRNAs (miRNAs) regulate pathways involved in cell differentiation, proliferation, development, and apoptosis by degradation of target mRNAs and/or repression of their translation. Although the single nucleotide polymorphisms (SNPs) in miRNAs target sites have been studied, the effects of SNPs in miRNAs are largely unknown. In our study, we first systematically sequenced miRNA genes reported to be involved in breast cancer to identify/verify SNPs. We analyzed four SNPs, one located in the pre-miRNA and the other three located in miRNA flanking regions, for a putative association with breast cancer risk. The SNP rs895819, located in the terminal loop of pre-miRNA-27a, showed a protective effect. In a large familial breast cancer study cohort, the rare [G] allele of rs895819 was found to be less frequent in the cases than in the controls, indicating a reduced familial breast cancer risk ([G] vs. [A]: OR = 0.88, 95% CI 0.78-0.99, P = 0.0287). Furthermore, age stratification revealed that the protective effect was mainly observed in the age group < 50 years of age ([G] vs. [A]: OR = 0.83, 95% CI 0.70-0.98, P = 0.0314), whereas no significant effect was observed in the age group >or= 50 years of age, indicating a possible hormone-related effect. It has been shown that artificial mutations in the terminal loop of miR-27a can block the maturation process of the miRNA. We hypothesize that the G-variant of rs895819 might impair the maturation of the oncogenic miR-27a and thus, is associated with familial breast cancer risk.
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Affiliation(s)
- Rongxi Yang
- Helmholtz-University Group Molecular Epidemiology, German Cancer Research Center, DKFZ, Im Neuenheimer Feld 581, 69120 Heidelberg, Germany.
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Liu LYD, Chen CY, Chen MJM, Tsai MS, Lee CHS, Phang TL, Chang LY, Kuo WH, Hwa HL, Lien HC, Jung SM, Lin YS, Chang KJ, Hsieh FJ. Statistical identification of gene association by CID in application of constructing ER regulatory network. BMC Bioinformatics 2009; 10:85. [PMID: 19292896 PMCID: PMC2679734 DOI: 10.1186/1471-2105-10-85] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Accepted: 03/17/2009] [Indexed: 02/01/2023] Open
Abstract
Background A variety of high-throughput techniques are now available for constructing comprehensive gene regulatory networks in systems biology. In this study, we report a new statistical approach for facilitating in silico inference of regulatory network structure. The new measure of association, coefficient of intrinsic dependence (CID), is model-free and can be applied to both continuous and categorical distributions. When given two variables X and Y, CID answers whether Y is dependent on X by examining the conditional distribution of Y given X. In this paper, we apply CID to analyze the regulatory relationships between transcription factors (TFs) (X) and their downstream genes (Y) based on clinical data. More specifically, we use estrogen receptor α (ERα) as the variable X, and the analyses are based on 48 clinical breast cancer gene expression arrays (48A). Results The analytical utility of CID was evaluated in comparison with four commonly used statistical methods, Galton-Pearson's correlation coefficient (GPCC), Student's t-test (STT), coefficient of determination (CoD), and mutual information (MI). When being compared to GPCC, CoD, and MI, CID reveals its preferential ability to discover the regulatory association where distribution of the mRNA expression levels on X and Y does not fit linear models. On the other hand, when CID is used to measure the association of a continuous variable (Y) against a discrete variable (X), it shows similar performance as compared to STT, and appears to outperform CoD and MI. In addition, this study established a two-layer transcriptional regulatory network to exemplify the usage of CID, in combination with GPCC, in deciphering gene networks based on gene expression profiles from patient arrays. Conclusion CID is shown to provide useful information for identifying associations between genes and transcription factors of interest in patient arrays. When coupled with the relationships detected by GPCC, the association predicted by CID are applicable to the construction of transcriptional regulatory networks. This study shows how information from different data sources and learning algorithms can be integrated to investigate whether relevant regulatory mechanisms identified in cell models can also be partially re-identified in clinical samples of breast cancers. Availability the implementation of CID in R codes can be freely downloaded from .
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Affiliation(s)
- Li-Yu D Liu
- Department of Agronomy, Biometry Division, National Taiwan University, Taipei, Taiwan.
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