1
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Angeles CV, Velez A, Rios J, Laxa B, Shum D, Ruiz PD, Shen Y, Ostrovnaya I, Gularte-Mérida R, Nacev BA, Dickson MA, Djaballah H, Okada T, Singer S. A High-Content Screen for C/EBPα Expression Identifies Novel Therapeutic Agents in Dedifferentiated Liposarcoma. Clin Cancer Res 2021; 28:175-186. [PMID: 34667024 DOI: 10.1158/1078-0432.ccr-19-2486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 06/21/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022]
Abstract
PURPOSE Dedifferentiated liposarcoma (DDLS), one of the most common and aggressive sarcomas, infrequently responds to chemotherapy. DDLS survival and growth depend on underexpression of C/EBPα, a tumor suppressor and transcriptional regulator controlling adipogenesis. We sought to screen and prioritize candidate drugs that increase C/EBPα expression and may therefore serve as differentiation-based therapies for DDLS. EXPERIMENTAL DESIGN We screened known bioactive compounds for the ability to restore C/EBPα expression and inhibit proliferation selectively in two DDLS cell lines but not in normal adipose-derived stem cells (ASC). Selected hits' activity was validated, and the mechanism of the most potent, SN-38, was investigated. The in vivo efficacy of irinotecan, the prodrug of SN-38, was evaluated in DDLS xenograft models. RESULTS Of 3,119 compounds, screen criteria were met by 19. Validation experiments confirmed the DDLS selectivity of deguelin, emetine, and SN-38 and showed that they induce apoptosis in DDLS cells. SN-38 had the lowest IC50 (approximately 10 nmol/L), and its pro-apoptotic effects were countered by knockdown of CEBPA but not of TP53. Irinotecan significantly inhibited tumor growth at well-tolerated doses, induced nuclear expression of C/EBPα, and inhibited HIF1α expression in DDLS patient-derived and cancer cell line xenograft models. In contrast, doxorubicin, the most common treatment for nonresectable DDLS, reduced tumor growth by 30% to 50% at a dose that caused weight loss. CONCLUSIONS This high-content screen revealed potential treatments for DDLS. These include irinotecan, which induces apoptosis of DDLS cells in a C/EBPα-dependent, p53-independent manner, and should be clinically evaluated in patients with advanced DDLS.
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Affiliation(s)
- Christina V Angeles
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ana Velez
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Jordan Rios
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Bernadette Laxa
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - David Shum
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Penelope D Ruiz
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Yawei Shen
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Irina Ostrovnaya
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Rodrigo Gularte-Mérida
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Benjamin A Nacev
- Department of Medicine, Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, New York
| | - Mark A Dickson
- Department of Medicine, Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, New York
| | - Hakim Djaballah
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Tomoyo Okada
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - Samuel Singer
- Sarcoma Biology Laboratory, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York. .,Department of Surgery, Weill Cornell Medical College, New York, New York
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2
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Ji L, Fu J, Hao J, Ji Y, Wang H, Wang Z, Wang P, Xiao H. Proteomics analysis of tissue small extracellular vesicles reveals protein panels for the reoccurrence prediction of colorectal cancer. J Proteomics 2021; 249:104347. [PMID: 34384913 DOI: 10.1016/j.jprot.2021.104347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/25/2021] [Accepted: 07/30/2021] [Indexed: 02/07/2023]
Abstract
Many stage II/III colorectal cancer (CRC) patients might relapse after routine treatment and there is a great need of reliable biomarkers for predicting its reoccurrence risk. Small extracellular vesicles (sEVs) could regulate many pathophysiological processes of diseases, which are promising source for biomarker discovery. In this study, we implemented a MS-based workflow that utilizes data-dependent acquisition (DDA) for discovery and parallel reaction monitoring (PRM) for validation of high relapse risk related biomarkers. We compared the protein profiling of sEVs from CRC tissues and paired adjacent tissues in relapsed group (n = 5) and non-relapsed group (n = 5). 417 and 1140 proteins were differentially expressed between the tumor tissues and adjacent tissues in relapsed group and non-relapsed group, respectively. Bioinformatics analysis showed that immunity of the relapsed patients (Z-score - 0.69) was relatively poorer than the non-relapsed patients (Z-score 2.59), while chronic inflammatory response was activated (Z-score 3.0), which might enhance the reoccurrence risk. Four proteins (HLA-DPA1, S100P, NUP205, PCNA) showed significant expressions in the adjacent tissues of the relapsed group by PRM validation. ROC analysis of HLA-DPA1 (AUC = 0.96) achieved the best classification accuracy in separating the relapsed group and the non-relapsed group. Our data demonstrate that tissue-derived sEVs harbor prognostic proteomic signatures of CRC. SIGNIFICANCE: In this research, our proteomics analysis of tissue sEVs revealed that poor immunity as well as chronic inflammatory of the CRC relapsed patient likely lead to poor prognosis and high risk of reoccurrence. The significant expression levels of four proteins (HLA-DPA1, S100P, NUP205, PCNA) in the adjacent tissues of the relapsed group might be used to predict the risk of relapse in postoperative follow-ups.
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Affiliation(s)
- Liyun Ji
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jihong Fu
- Department of Colorectal Surgery, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Jie Hao
- Shanghai Centre for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yin Ji
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Pharmaceutical Co., Ltd, Nanjing 210042, China
| | - Huiyu Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zeyuan Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Peng Wang
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Pharmaceutical Co., Ltd, Nanjing 210042, China.
| | - Hua Xiao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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3
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Nacht AS, Ferrari R, Zaurin R, Scabia V, Carbonell-Caballero J, Le Dily F, Quilez J, Leopoldi A, Brisken C, Beato M, Vicent GP. C/EBPα mediates the growth inhibitory effect of progestins on breast cancer cells. EMBO J 2019; 38:e101426. [PMID: 31373033 DOI: 10.15252/embj.2018101426] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/21/2019] [Accepted: 06/24/2019] [Indexed: 01/19/2023] Open
Abstract
Steroid hormones are key gene regulators in breast cancer cells. While estrogens stimulate cell proliferation, progestins activate a single cell cycle followed by proliferation arrest. Here, we use biochemical and genome-wide approaches to show that progestins achieve this effect via a functional crosstalk with C/EBPα. Using ChIP-seq, we identify around 1,000 sites where C/EBPα binding precedes and helps binding of progesterone receptor (PR) in response to hormone. These regions exhibit epigenetic marks of active enhancers, and C/EBPα maintains an open chromatin conformation that facilitates loading of ligand-activated PR. Prior to hormone exposure, C/EBPα favors promoter-enhancer contacts that assure hormonal regulation of key genes involved in cell proliferation by facilitating binding of RAD21, YY1, and the Mediator complex. Knockdown of C/EBPα disrupts enhancer-promoter contacts and decreases the presence of these architectural proteins, highlighting its key role in 3D chromatin looping. Thus, C/EBPα fulfills a previously unknown function as a potential growth modulator in hormone-dependent breast cancer.
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Affiliation(s)
- A Silvina Nacht
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Roberto Ferrari
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Roser Zaurin
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Valentina Scabia
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - José Carbonell-Caballero
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Francois Le Dily
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Javier Quilez
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Alexandra Leopoldi
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
| | - Cathrin Brisken
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Miguel Beato
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Guillermo P Vicent
- Center for Genomic Regulation (CRG), Barcelona, Spain.,Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
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4
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A tumor suppressor role for C/EBPα in solid tumors: more than fat and blood. Oncogene 2017; 36:5221-5230. [PMID: 28504718 DOI: 10.1038/onc.2017.151] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/29/2017] [Accepted: 04/10/2017] [Indexed: 12/12/2022]
Abstract
The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) plays a critical role during embryogenesis and is thereafter required for homeostatic glucose metabolism, adipogenesis and myeloid development. Its ability to regulate the expression of lineage-specific genes and induce growth arrest contributes to the terminal differentiation of several cell types, including hepatocytes, adipocytes and granulocytes. CEBPA loss of-function mutations contribute to the development of ~10% of acute myeloid leukemia (AML), stablishing a tumor suppressor role for C/EBPα. Deregulation of C/EBPα expression has also been reported in a variety of additional human neoplasias, including liver, breast and lung cancer. However, functional CEBPA mutations have not been found in solid tumors, suggesting that abrogation of C/EBPα function in non-hematopoietic tissues is regulated by alternative mechanisms. Here we review the function of C/EBPα in solid tumors and focus on the molecular mechanisms underlying its tumor suppressive role.
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5
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Li Q, Li J, Wen T, Zeng W, Peng C, Yan S, Tan J, Yang K, Liu S, Guo A, Zhang C, Su J, Jiang M, Liu Z, Zhou H, Chen X. Overexpression of HMGB1 in melanoma predicts patient survival and suppression of HMGB1 induces cell cycle arrest and senescence in association with p21 (Waf1/Cip1) up-regulation via a p53-independent, Sp1-dependent pathway. Oncotarget 2014; 5:6387-403. [PMID: 25051367 PMCID: PMC4171638 DOI: 10.18632/oncotarget.2201] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 07/09/2014] [Indexed: 11/25/2022] Open
Abstract
Although laboratory studies have implicated the high mobility group box 1 (HMGB1) in melanoma, its clinical relevance remains unclear. We analyzed nearly 100 cases of human melanoma and found that HMGB1 was highly overexpressed in melanoma samples relative to normal skin and nevi tissues. Significantly, higher levels of HMGB1 correlated with more advanced disease stages and with poorer survival in melanoma patients. Unlike the well-documented pro-inflammatory role of the extracellular HMGB1, we found that its intracellular activity is necessary for melanoma cell proliferation. An absolute dependency of melanoma cell proliferation on HMGB1 was underscored by the marked response of cell cycle arrest and senescence to HMGB1 knockdown. We demonstrated that HMGB1 deficiency-induced inhibition of cell proliferation was mediated by p21, which was induced via a Sp1-dependent mechanism. Taken together, our data demonstrate a novel oncogenic role of HMGB1 in promoting human melanoma cell proliferation and have important implications in melanoma patient care.
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Affiliation(s)
- Qingling Li
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Jie Li
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Ting Wen
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Weiqi Zeng
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Cong Peng
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Siyu Yan
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Jieqiong Tan
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha, 410008, China
| | - Keda Yang
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Shuang Liu
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Aiyuan Guo
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Chong Zhang
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Juan Su
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Minghao Jiang
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Zhaoqian Liu
- Institute of Clinical Pharmacology, Xiangya School of Medicine, Central South University, Changsha, 410008, China
| | - Honghao Zhou
- Institute of Clinical Pharmacology, Xiangya School of Medicine, Central South University, Changsha, 410008, China
| | - Xiang Chen
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, China
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6
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E6AP, an E3 ubiquitin ligase negatively regulates granulopoiesis by targeting transcription factor C/EBPα for ubiquitin-mediated proteasome degradation. Cell Death Dis 2013; 4:e590. [PMID: 23598402 PMCID: PMC3641343 DOI: 10.1038/cddis.2013.120] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CCAAT/enhancer-binding protein alpha (C/EBPα) is an important transcription factor involved in granulocytic differentiation. Here, for the first time we demonstrate that E6-associated protein (E6AP), an E3 ubiquitin ligase targets C/EBPα for ubiquitin-mediated proteasome degradation and thereby negatively modulates its functions. Wild-type E6AP promotes ubiquitin dependent proteasome degradation of C/EBPα, while catalytically inactive E6-associated protein having cysteine replaced with alanine at amino-acid position 843 (E6AP-C843A) rather stabilizes it. Further, these two proteins physically associate both in non-myeloid (overexpressed human embryonic kidney epithelium) and myeloid cells. We show that E6AP-mediated degradation of C/EBPα protein expression curtails its transactivation potential on its target genes. Noticeably, E6AP degrades both wild-type 42 kDa CCAAT-enhancer-binding protein alpha (p42C/EBPα) and mutant isoform 30 kDa CCAAT-enhancer-binding protein alpha (p30C/EBPα), this may explain perturbed p42C/EBPα/p30C/EBPα ratio often observed in acute myeloid leukemia (AML). We show that overexpression of catalytically inactive E6AP-C843A in C/EBPα inducible K562- p42C/EBPα-estrogen receptor (ER) cells inhibits β-estradiol (E2)-induced C/EBPα degradation leading to enhanced granulocytic differentiation. This enhanced granulocytic differentiation upon E2-induced activation of C/EBPα in C/EBPα stably transfected cells (β-estradiol inducible K562 cells stably expressing p42C/EBPα-ER (K562-C/EBPα-p42-ER)) was further substantiated by siE6AP-mediated knockdown of E6AP in both K562-C/EBPα-p42-ER and 32dcl3 (32D clone 3, a cell line widely used model for in vitro study of hematopoietic cell proliferation, differentiation, and apoptosis) cells. Taken together, our data suggest that E6AP targeted C/EBPα protein degradation may provide a possible explanation for both loss of expression and/or functional inactivation of C/EBPα often experienced in myeloid leukemia.
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7
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Abstract
Artemisinin, a sesquiterpene lactone derived from the sweet wormwood plant Artemisia annua, and its bioactive derivatives exhibit potent anticancer effects in a variety of human cancer cell model systems. The pleiotropic response in cancer cells includes growth inhibition by cell cycle arrest, apoptosis, inhibition of angiogenesis, disruption of cell migration, and modulation of nuclear receptor responsiveness. These effects of artemisinin and its derivatives result from perturbations of many cellular signalling pathways. This review provides a comprehensive discussion of these cellular responses, and considers the ramifications for the potential development of artemisinin-based compounds in anticancer therapeutic and preventative strategies.
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8
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Pal P, Lochab S, Kanaujiya J, Sanyal S, Trivedi AK. Ectopic expression of hC/EBPs in breast tumor cells induces apoptosis. Mol Cell Biochem 2009; 337:111-8. [PMID: 19851833 DOI: 10.1007/s11010-009-0290-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 10/08/2009] [Indexed: 11/29/2022]
Abstract
CCAAT/enhancer binding proteins (C/EBPs) are a group of transcription factors which have been implicated in cellular proliferation, terminal differentiation, and apoptosis in a variety of tissues including mammary gland. Owing to its role in various cellular functions, inactivation of C/EBP proteins is central to the pathogenesis of many disorders. Recent reports suggest that expression as well as function of C/EBP proteins is deregulated in breast tumors. Although, role of C/EBPs in growth arrest in mammary tissues has been studied in much detail; their role in apoptosis is relatively less explored. In the present study, we have assessed if breast tumors evade apoptosis and grow faster by down regulating and inhibiting the C/EBP proteins, C/EBPalpha in particular. Our data shows that ectopic expression of human C/EBPs in breast tumor cells inhibits proliferation and induces apoptosis which is likely to be associated with caspase dependent pathway.
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Affiliation(s)
- Pooja Pal
- Drug Target Discovery and Development Division (DTDD), Central Drug Research Institute, CDRI, Chhattar Manzil, Lucknow, UP, India
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9
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Dhawan P, Wieder R, Christakos S. CCAAT enhancer-binding protein alpha is a molecular target of 1,25-dihydroxyvitamin D3 in MCF-7 breast cancer cells. J Biol Chem 2009; 284:3086-3095. [PMID: 19054766 PMCID: PMC2631956 DOI: 10.1074/jbc.m803602200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 12/02/2008] [Indexed: 11/06/2022] Open
Abstract
Numerous studies have shown that the active form of vitamin D, 1,25(OH)(2)D(3), can exert growth inhibitory effects on human breast cancer cells and mammary tumor growth. However, the molecular mechanisms remain to be fully delineated. This study demonstrates for the first time that CCAAT enhancer-binding protein alpha (C/EBPalpha), a member of the C/EBP family of transcription factors, is induced by 1,25(OH)(2)D(3) and is a potent enhancer of VDR transcription in MCF-7 breast cancer cells. 1,25(OH)(2)D(3) was found to induce C/EBPalpha as well as VDR expression in MCF-7 cells. C/EBPalpha was not detected in MDA-MB-231 cells that are poorly responsive to 1,25(OH)(2)D(3). Antiproliferative effects of 1,25(OH)(2)D(3) and induction of VDR were observed in MDA-MB-231 cells transfected with C/EBPalpha, and knockdown of C/EBPalpha suppressed VDR and antiproliferative effects of 1,25(OH)(2)D(3) in MCF-7 cells. Transfection of C/EBPalpha in MCF-7 cells resulted in a dose-dependent enhancement of hVDR transcription. Our studies show that C/EBPalpha can bind to Brahma (Brm), an ATPase that is a component of the SWI/SNF complex, and cooperate with Brm in the regulation of hVDR transcription in MCF-7 cells. Because the levels of VDR in MCF-7 breast cancer cells correlate with the antiproliferative effects of 1,25(OH)(2)D(3) and because C/EBPalpha has been suggested as a potential tumor suppressor in breast cancer, these findings provide important mechanisms whereby 1,25(OH)(2)D(3) may act to inhibit growth of breast cancer cells. These findings also identify C/EBPalpha as a 1,25(OH)(2)D(3) target in breast cancer cells and provide evidence for C/EBPalpha as a candidate for breast cancer treatment.
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Affiliation(s)
- Puneet Dhawan
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103
| | - Robert Wieder
- Department of Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103
| | - Sylvia Christakos
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103.
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10
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Wang X, Huang G, Mei S, Qian J, Ji J, Zhang J. Over-expression of C/EBP-alpha induces apoptosis in cultured rat hepatic stellate cells depending on p53 and peroxisome proliferator-activated receptor-gamma. Biochem Biophys Res Commun 2009; 380:286-91. [PMID: 19168033 DOI: 10.1016/j.bbrc.2009.01.060] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 01/12/2023]
Abstract
Hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic fibrosis. In our previous studies, CCAAT enhancer binding protein-alpha (C/EBP-alpha) has been shown to be involved in the activation of HSCs and to have a repression effect on hepatic fibrosis in vivo. However, the mechanisms are largely unknown. In this study, we show that the infection of adenovirus vector expressing C/EBP-alpha gene (Ad-C/EBP-alpha) could induce HSCs apoptosis in a dose- and time-dependent manner by Annexin V/PI staining, caspase-3 activation assay, and flow cytometry. Also, over-expression of C/EBP-alpha resulted in the up-regulation of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and P53, while P53 expression was regulated by PPAR-gamma. In addition, Fas, FasL, DR4, DR5, and TRAIL were studied. The results indicated that the death receptor pathway was mainly involved and regulated by PPAR-gamma and p53 in the process of apoptosis triggered by C/EBP-alpha in HSCs.
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Affiliation(s)
- Xueqing Wang
- Department of Pathology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, PR China
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11
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Mao C, Patterson NM, Cherian MT, Aninye IO, Zhang C, Montoya JB, Cheng J, Putt KS, Hergenrother PJ, Wilson EM, Nardulli AM, Nordeen SK, Shapiro DJ. A new small molecule inhibitor of estrogen receptor alpha binding to estrogen response elements blocks estrogen-dependent growth of cancer cells. J Biol Chem 2008; 283:12819-30. [PMID: 18337247 PMCID: PMC2442351 DOI: 10.1074/jbc.m709936200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/12/2008] [Indexed: 12/21/2022] Open
Abstract
Estrogen receptor alpha (ERalpha) plays an important role in several human cancers. Most current ERalpha antagonists bind in the receptor ligand binding pocket and compete for binding with estrogenic ligands. Instead of the traditional approach of targeting estrogen binding to ER, we describe a strategy using a high throughput fluorescence anisotropy microplate assay to identify small molecule inhibitors of ERalpha binding to consensus estrogen response element (cERE) DNA. We identified small molecule inhibitors of ERalpha binding to the fluorescein-labeled (fl)cERE and evaluated their specificity, potency, and efficacy. One small molecule, theophylline, 8-[(benzylthio)methyl]-(7CI,8CI) (TPBM), inhibited ERalpha binding to the flcERE (IC(50) approximately 3 microm) and inhibited ERalpha-mediated transcription of a stably transfected ERE-containing reporter gene. Inhibition by TPBM was ER-specific, because progesterone and glucocorticoid receptor transcriptional activity were not significantly inhibited. In tamoxifen-resistant breast cancer cells that overexpress ERalpha, TPBM inhibited 17beta-estradiol (E(2))-ERalpha (IC(50) 9 microm) and 4-hydroxytamoxifen-ERalpha-mediated gene expression. Chromatin immunoprecipitation showed TPBM reduced E(2).ERalpha recruitment to an endogenous estrogen-responsive gene. TPBM inhibited E(2)-dependent growth of ERalpha-positive cancer cells (IC(50) of 5 microm). TPBM is not toxic to cells and does not affect estrogen-independent cell growth. TPBM acts outside of the ER ligand binding pocket, does not act by chelating the zinc in ER zinc fingers, and differs from known ERalpha inhibitors. Using a simple high throughput screen for inhibitors of ERalpha binding to the cERE, a small molecule inhibitor has been identified that selectively inhibits ERalpha-mediated gene expression and estrogen-dependent growth of cancer cells.
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Affiliation(s)
- Chengjian Mao
- Department of Biochemistry, and Chemistry, University of Illinois, Urbana, Illinois 61810-3602, USA
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