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Yin Q, Hu Y, Dong Z, Lu J, Wang H. Cellular, Structural Basis, and Recent Progress for Targeting Murine Double Minute X (MDMX) in Tumors. J Med Chem 2024; 67:14723-14741. [PMID: 39185935 DOI: 10.1021/acs.jmedchem.4c00913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Murine double minute X (MDMX) is an oncoprotein that mainly has a negative regulatory effect on the tumor suppressor p53 to induce tumorigenesis. As MDMX is highly expressed in various types of tumor cells, targeting and inhibiting MDMX are becoming a promising strategy for treating cancers. However, the high degree of structural homology between MDMX and its homologous protein murine double minute 2 (MDM2) is a great challenge for the development of MDMX-targeted therapies. This review introduces the structure, distribution, and regulation of the MDMX, summarizes the structural features and structure-activity relationships (SARs) of MDMX ligands, and focuses on the differences between MDMX and MDM2 in these aspects. Our purpose of this work is to propose potential strategies to achieve the specific targeting of MDMX.
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Affiliation(s)
- Qikun Yin
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Yuemiao Hu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Zhiwen Dong
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Jing Lu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Hongbo Wang
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
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Pyne E, Reardon M, Christensen M, Rodriguez Mateos P, Taylor S, Iles A, Choudhury A, Pamme N, Pires IM. Investigating the impact of the interstitial fluid flow and hypoxia interface on cancer transcriptomes using a spheroid-on-chip perfusion system. LAB ON A CHIP 2024. [PMID: 39258507 PMCID: PMC11388701 DOI: 10.1039/d4lc00512k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Solid tumours are complex and heterogeneous systems, which exist in a dynamic biophysical microenvironment. Conventional cancer research methods have long relied on two-dimensional (2D) static cultures which neglect the dynamic, three-dimensional (3D) nature of the biophysical tumour microenvironment (TME), especially the role and impact of interstitial fluid flow (IFF). To address this, we undertook a transcriptome-wide analysis of the impact of IFF-like perfusion flow using a spheroid-on-chip microfluidic platform, which allows 3D cancer spheroids to be integrated into extracellular matrices (ECM)-like hydrogels and exposed to continuous perfusion, to mimic IFF in the TME. Importantly, we have performed these studies both in experimental (normoxia) and pathophysiological (hypoxia) oxygen conditions. Our data indicated that gene expression was altered by flow when compared to static conditions, and for the first time showed that these gene expression patterns differed in different oxygen tensions, reflecting a differential role of spheroid perfusion in IFF-like flow in tumour-relevant hypoxic conditions in the biophysical TME. We were also able to identify factors primarily linked with IFF-like conditions which are linked with prognostic value in cancer patients and therefore could correspond to a potential novel biomarker of IFF in cancer. This study therefore highlights the need to consider relevant oxygen conditions when studying the impact of flow in cancer biology, as well as demonstrating the potential of microfluidic models of flow to identify IFF-relevant tumour biomarkers.
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Affiliation(s)
- Emily Pyne
- Centre for Biomedicine, HYMS, University of Hull, Hull, UK
| | - Mark Reardon
- Translational Radiobiology, Division of Cancer Sciences, University of Manchester, Manchester, UK
| | | | - Pablo Rodriguez Mateos
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Scott Taylor
- Tumour Hypoxia Biology, Division of Cancer Sciences, University of Manchester, Manchester, UK.
| | - Alexander Iles
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Ananya Choudhury
- Translational Radiobiology, Division of Cancer Sciences, University of Manchester, Manchester, UK
- Christie Hospital NHS Foundation Trust, Manchester, UK
| | - Nicole Pamme
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Isabel M Pires
- Centre for Biomedicine, HYMS, University of Hull, Hull, UK
- Tumour Hypoxia Biology, Division of Cancer Sciences, University of Manchester, Manchester, UK.
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Gao Y, Qiao X, Liu Z, Zhang W. The role of E2F2 in cancer progression and its value as a therapeutic target. Front Immunol 2024; 15:1397303. [PMID: 38807594 PMCID: PMC11130366 DOI: 10.3389/fimmu.2024.1397303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 04/30/2024] [Indexed: 05/30/2024] Open
Abstract
The E2F family of transcription factors plays a crucial role in the regulation of cell cycle progression and cell proliferation. Accumulative evidence indicates that aberrant expression or activation of E2F2 is a common phenomenon in malignances. E2F2 has emerged as a key player in the development and progression of various types of tumors. A wealth of research has substantiated that E2F2 could contribute to the enhancement of tumor cell proliferation, angiogenesis, and invasiveness. Moreover, E2F2 exerts its influence on a myriad of cellular processes by engaging with a spectrum of auxiliary factors and downstream targets, including apoptosis and DNA repair. The dysregulation of E2F2 in the context of carcinogenesis may be attributable to a multitude of mechanisms, which encompass modifications in upstream regulatory elements or epigenetic alterations. This review explores the function of E2F2 in cancer progression and both established and emerging therapeutic strategies aiming at targeting this oncogenic pathway, while also providing a strong basis for further research on the biological function and clinical applications of E2F2.
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Affiliation(s)
- Yang Gao
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou, China
| | - Xinjie Qiao
- Department of Rhinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhenhui Liu
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou, China
| | - Wenzhou Zhang
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou, China
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Yang X, Bai Z, He Y, Wang N, Sun L, Li Y, Yin Z, Wang X, Zhang B, Han M, Lu X, Chen X, Wang D, Wang J, Wang S, Guo L, Chen C, Feng K, Ye W. Genome-wide characterization of DNA methyltransferase family genes implies GhDMT6 improving tolerance of salt and drought on cotton. BMC PLANT BIOLOGY 2024; 24:312. [PMID: 38649800 PMCID: PMC11036760 DOI: 10.1186/s12870-024-04985-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/03/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND DNA methylation is an important epigenetic mode of genomic DNA modification and plays a vital role in maintaining epigenetic content and regulating gene expression. Cytosine-5 DNA methyltransferase (C5-MTase) are the key enzymes in the process of DNA methylation. However, there is no systematic analysis of the C5-MTase in cotton so far, and the function of DNMT2 genes has not been studied. METHODS In this study, the whole genome of cotton C5-MTase coding genes was identified and analyzed using a bioinformatics method based on information from the cotton genome, and the function of GhDMT6 was further validated by VIGS experiments and subcellular localization analysis. RESULTS 33 C5-MTases were identified from three cotton genomes, and were divided into four subfamilies by systematic evolutionary analysis. After the protein domain alignment of C5-MTases in cotton, 6 highly conserved motifs were found in the C-terminus of 33 proteins involved in methylation modification, which indicated that C5-MTases had a basic catalytic methylation function. These proteins were divided into four classes based on the N-terminal difference, of which DNMT2 lacks the N-terminal regulatory domain. The expression of C5-MTases in different parts of cotton was different under different stress treatments, which indicated the functional diversity of cotton C5-MTase gene family. Among the C5-MTases, the GhDMT6 had a obvious up-regulated expression. After silencing GhDMT6 with VIGS, the phenotype of cotton seedlings under different stress treatments showed a significant difference. Compared with cotton seedlings that did not silence GhDMT6, cotton seedlings silencing GhDMT6 showed significant stress resistance. CONCLUSION The results show that C5-MTases plays an important role in cotton stress response, which is beneficial to further explore the function of DNMT2 subfamily genes.
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Affiliation(s)
- Xiaomin Yang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
- Cash Crop Research Institute of Jiangxi Province, Jiujiang, Jiangxi, 332105, China
| | - Zhigang Bai
- Cash Crop Research Institute of Jiangxi Province, Jiujiang, Jiangxi, 332105, China
| | - Yunxin He
- Hunan Institute of Cotton Science, Changde, Hunan, 415101, China
| | - Ning Wang
- Institute of Crop Sciences, Gansu Academy of Agricultural Sciences, Lanzhou, Gansu, 730070, China
| | - Liangqing Sun
- Cash Crop Research Institute of Jiangxi Province, Jiujiang, Jiangxi, 332105, China
| | - Yongqi Li
- Cash Crop Research Institute of Jiangxi Province, Jiujiang, Jiangxi, 332105, China
| | - Zujun Yin
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Xiaoge Wang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Binglei Zhang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Mingge Han
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Xuke Lu
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Xiugui Chen
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Delong Wang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Junjuan Wang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Shuai Wang
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Lixue Guo
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Chao Chen
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China
| | - Keyun Feng
- Institute of Crop Sciences, Gansu Academy of Agricultural Sciences, Lanzhou, Gansu, 730070, China.
| | - Wuwei Ye
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences / Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Anyang, Henan, 455000, China.
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Pérez-Benavente B, Fathinajafabadi A, de la Fuente L, Gandía C, Martínez-Férriz A, Pardo-Sánchez JM, Milián L, Conesa A, Romero OA, Carretero J, Matthiesen R, Jariel-Encontre I, Piechaczyk M, Farràs R. New roles for AP-1/JUNB in cell cycle control and tumorigenic cell invasion via regulation of cyclin E1 and TGF-β2. Genome Biol 2022; 23:252. [PMID: 36494864 PMCID: PMC9733061 DOI: 10.1186/s13059-022-02800-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 10/20/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND JUNB transcription factor contributes to the formation of the ubiquitous transcriptional complex AP-1 involved in the control of many physiological and disease-associated functions. The roles of JUNB in the control of cell division and tumorigenic processes are acknowledged but still unclear. RESULTS Here, we report the results of combined transcriptomic, genomic, and functional studies showing that JUNB promotes cell cycle progression via induction of cyclin E1 and repression of transforming growth factor (TGF)-β2 genes. We also show that high levels of JUNB switch the response of TGF-β2 stimulation from an antiproliferative to a pro-invasive one, induce endogenous TGF-β2 production by promoting TGF-β2 mRNA translation, and enhance tumor growth and metastasis in mice. Moreover, tumor genomic data indicate that JUNB amplification associates with poor prognosis in breast and ovarian cancer patients. CONCLUSIONS Our results reveal novel functions for JUNB in cell proliferation and tumor aggressiveness through regulation of cyclin E1 and TGF-β2 expression, which might be exploited for cancer prognosis and therapy.
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Affiliation(s)
| | | | - Lorena de la Fuente
- Centro de Investigación Príncipe Felipe, Valencia, Spain
- Present Address: PerkinElmer Informatics, Tres Cantos, Madrid, Spain
| | | | | | | | - Lara Milián
- Department of Pathology, Faculty of Medicine and Dentistry, Universitat de València, Valencia, Spain
- INCLIVA Biomedical Research Institute, 46010, Valencia, Spain
| | - Ana Conesa
- Spanish National Research Council, Institute for Integrative Systems Biology, Paterna, Valencia, Spain
- Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Octavio A Romero
- Cancer Genetics Group, Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, Spain
| | - Julián Carretero
- Departament de Fisiologia, Facultat de Farmacia, Universitat de València, Burjassot, Valencia, Spain
| | - Rune Matthiesen
- Computational and Experimental Biology Group, NOVA Medical School-Research, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Isabelle Jariel-Encontre
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
- Present address: IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Montpellier, France
| | - Marc Piechaczyk
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Rosa Farràs
- Centro de Investigación Príncipe Felipe, Valencia, Spain.
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6
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Du K, Sun S, Jiang T, Liu T, Zuo X, Xia X, Liu X, Wang Y, Bu Y. E2F2 promotes lung adenocarcinoma progression through B-Myb- and FOXM1-facilitated core transcription regulatory circuitry. Int J Biol Sci 2022; 18:4151-4170. [PMID: 35844795 PMCID: PMC9274503 DOI: 10.7150/ijbs.72386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/14/2022] [Indexed: 11/15/2022] Open
Abstract
Lung adenocarcinoma (LUAD) causes severe cancer death worldwide. E2F2 is a canonical transcription factor implicated in transcription regulation, cell cycle and tumorigenesis. The role of E2F2 as well as its transcription regulatory network in LUAD remains obscure. In this study, we constructed a weighted gene co-expression network and identified several key modules and networks overrepresented in LUAD, including the E2F2-centered transcription regulatory network. Function analysis revealed that E2F2 overexpression accelerated cell growth, cell cycle progression and cell motility in LUAD cells whereas E2F2 knockdown inhibited these malignant phenotypes. Mechanistic investigations uncovered various E2F2-regulated downstream genes and oncogenic signaling pathways. Notably, three core transcription factors of E2F2, B-Myb and FOXM1 from the LUAD transcription regulatory network exhibited positive expression correlation, associated with each other, mutually transactivated each other, and regulated similar downstream gene cascades, hence constituting a consolidated core transcription regulatory circuitry. Moreover, E2F2 could promote and was essentially required for LUAD growth in orthotopic mouse models. Prognosis modeling revealed that a two-gene signature of E2F2 and PLK1 from the transcription regulatory circuitry remarkably stratified patients into low- and high-risk groups. Collectively, our results clarified the critical roles of E2F2 and the exquisite core transcription regulatory circuitry of E2F2/B-Myb/FOXM1 in LUAD progression.
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Affiliation(s)
- Kailong Du
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Shijie Sun
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Tinghui Jiang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Tao Liu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Xiaofeng Zuo
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Xing Xia
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Xianjun Liu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Yitao Wang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
| | - Youquan Bu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China
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7
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Wagner KD, Wagner N. The Senescence Markers p16INK4A, p14ARF/p19ARF, and p21 in Organ Development and Homeostasis. Cells 2022; 11:cells11121966. [PMID: 35741095 PMCID: PMC9221567 DOI: 10.3390/cells11121966] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/15/2022] [Accepted: 06/15/2022] [Indexed: 02/07/2023] Open
Abstract
It is widely accepted that senescent cells accumulate with aging. They are characterized by replicative arrest and the release of a myriad of factors commonly called the senescence-associated secretory phenotype. Despite the replicative cell cycle arrest, these cells are metabolically active and functional. The release of SASP factors is mostly thought to cause tissue dysfunction and to induce senescence in surrounding cells. As major markers for aging and senescence, p16INK4, p14ARF/p19ARF, and p21 are established. Importantly, senescence is also implicated in development, cancer, and tissue homeostasis. While many markers of senescence have been identified, none are able to unambiguously identify all senescent cells. However, increased levels of the cyclin-dependent kinase inhibitors p16INK4A and p21 are often used to identify cells with senescence-associated phenotypes. We review here the knowledge of senescence, p16INK4A, p14ARF/p19ARF, and p21 in embryonic and postnatal development and potential functions in pathophysiology and homeostasis. The establishment of senolytic therapies with the ultimate goal to improve healthy aging requires care and detailed knowledge about the involvement of senescence and senescence-associated proteins in developmental processes and homeostatic mechanism. The review contributes to these topics, summarizes open questions, and provides some directions for future research.
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Engeland K. Cell cycle regulation: p53-p21-RB signaling. Cell Death Differ 2022; 29:946-960. [PMID: 35361964 PMCID: PMC9090780 DOI: 10.1038/s41418-022-00988-z] [Citation(s) in RCA: 356] [Impact Index Per Article: 178.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 12/12/2022] Open
Abstract
The retinoblastoma protein RB and the transcription factor p53 are central tumor suppressors. They are often found inactivated in various tumor types. Both proteins play central roles in regulating the cell division cycle. RB forms complexes with the E2F family of transcription factors and downregulates numerous genes. Among the RB-E2F target genes, a large number code for key cell cycle regulators. Their transcriptional repression by the RB-E2F complex is released through phosphorylation of RB, leading to expression of the cell cycle regulators. The release from repression can be prevented by the cyclin-dependent kinase inhibitor p21/CDKN1A. The CDKN1A gene is transcriptionally activated by p53. Taken together, these elements constitute the p53-p21-RB signaling pathway. Following activation of p53, for example by viral infection or induction of DNA damage, p21 expression is upregulated. High levels of p21 then result in RB-E2F complex formation and downregulation of a large number of cell cycle genes. Thus, p53-dependent transcriptional repression is indirect. The reduced expression of the many regulators leads to cell cycle arrest. Examination of the p53-p21-RB targets and genes controlled by the related p53-p21-DREAM signaling pathway reveals that there is a large overlap of the two groups. Mechanistically this can be explained by replacing RB-E2F complexes with the DREAM transcriptional repressor complex at E2F sites in target promoters. In contrast to RB-E2F, DREAM can downregulate genes also through CHR transcription factor binding sites. This results in a distinct gene set controlled by p53-p21-DREAM signaling independent of RB-E2F. Furthermore, RB has non-canonical functions without binding to E2F and DNA. Such a role of RB supporting DREAM formation may be exerted by the RB-SKP2-p27-cyclin A/E-CDK2-p130-DREAM link. In the current synopsis, the mechanism of regulation by p53-p21-RB signaling is assessed and the overlap with p53-p21-DREAM signaling is examined. ![]()
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Affiliation(s)
- Kurt Engeland
- Molecular Oncology, Medical School, University of Leipzig, Semmelweisstrasse 14, 04103, Leipzig, Germany.
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9
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Fan X, Wang Y, Jiang T, Liu T, Jin Y, Du K, Niu Y, Zhang C, Liu Z, Lei Y, Bu Y. B-Myb accelerates colorectal cancer progression through reciprocal feed-forward transactivation of E2F2. Oncogene 2021; 40:5613-5625. [PMID: 34316028 PMCID: PMC8445821 DOI: 10.1038/s41388-021-01961-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 07/04/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022]
Abstract
B-Myb is an important transcription factor that plays a critical role in gene expression regulation and tumorigenesis. However, its functional implication in colorectal cancer remains elusive. In this study, we found that B-Myb was significantly upregulated at both mRNA and protein levels in colorectal cancer samples compared to non-tumor counterparts. B-Myb overexpression accelerated cell proliferation, cell cycle progression and cell motility in colorectal cancer cells, and promoted tumor growth in orthotopic nude mouse models in vivo. In contrast, B-Myb depletion inhibited these malignant phenotypes. Mechanistic investigations revealed that E2F2 was a novel transcriptional target of B-Myb and is essential to B-Myb-induced malignant phenotypes. Notably, B-Myb and E2F2 exhibited positive expression correlation, and interacted with each other in colorectal cancer cells. In addition to their autoregulatory mechanisms, B-Myb and E2F2 can also directly transactivate each other, thus constituting consolidated reciprocal feed-forward transactivation loops. Moreover, both B-Myb and E2F2 are required for the activation of ERK and AKT signaling pathways in colorectal cancer cells. Taken together, our data clarified a critical role for B-Myb in colorectal cancer and unraveled an exquisite mutual collaboration and reciprocal cross regulation between B-Myb and E2F2 that contribute to the malignant progression of human colorectal cancer.
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Affiliation(s)
- Xiaoyan Fan
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
- Dermopathic Research Institute, Taizhou University Hospital, Taizhou University, Taizhou, China
| | - Yitao Wang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China
| | - Tinghui Jiang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Tao Liu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Yuelei Jin
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Kailong Du
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Yulong Niu
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China
| | - Chunxue Zhang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Zhongyu Liu
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China
| | - Yunlong Lei
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China.
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China.
| | - Youquan Bu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China.
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China.
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10
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Baroni M, Yi C, Choudhary S, Lei X, Kosti A, Grieshober D, Velasco M, Qiao M, Burns SS, Araujo PR, DeLambre T, Son MY, Plateroti M, Ferreira MAR, Hasty EP, Penalva LOF. Musashi1 Contribution to Glioblastoma Development via Regulation of a Network of DNA Replication, Cell Cycle and Division Genes. Cancers (Basel) 2021; 13:1494. [PMID: 33804958 PMCID: PMC8036803 DOI: 10.3390/cancers13071494] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/17/2021] [Accepted: 03/21/2021] [Indexed: 11/21/2022] Open
Abstract
RNA-binding proteins (RBPs) function as master regulators of gene expression. Alterations in their levels are often observed in tumors with numerous oncogenic RBPs identified in recent years. Musashi1 (Msi1) is an RBP and stem cell gene that controls the balance between self-renewal and differentiation. High Msi1 levels have been observed in multiple tumors including glioblastoma and are often associated with poor patient outcomes and tumor growth. A comprehensive genomic analysis identified a network of cell cycle/division and DNA replication genes and established these processes as Msi1's core regulatory functions in glioblastoma. Msi1 controls this gene network via two mechanisms: direct interaction and indirect regulation mediated by the transcription factors E2F2 and E2F8. Moreover, glioblastoma lines with Msi1 knockout (KO) displayed increased sensitivity to cell cycle and DNA replication inhibitors. Our results suggest that a drug combination strategy (Msi1 + cell cycle/DNA replication inhibitors) could be a viable route to treat glioblastoma.
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Affiliation(s)
- Mirella Baroni
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Caihong Yi
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
- Third Xiangya Hospital, Central South University, Changsha 410000, China
| | - Saket Choudhary
- Computational Biology and Bioinformatics, University of Southern California, Los Angeles, CA 90089, USA;
| | - Xiufen Lei
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Adam Kosti
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX 78229, USA
| | - Denise Grieshober
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Mitzli Velasco
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Mei Qiao
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Suzanne S. Burns
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Patricia R. Araujo
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Talia DeLambre
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
| | - Mi Young Son
- Department of Molecular Medicine, Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio, TX 78229, USA; (M.Y.S.); (E.P.H.)
| | - Michelina Plateroti
- Team: Development, Cancer and Stem Cells, Université de Strasbourg, Inserm, IRFAC/UMR-S1113, FMTS, 67200 Strasbourg, France;
| | | | - E. Paul Hasty
- Department of Molecular Medicine, Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio, TX 78229, USA; (M.Y.S.); (E.P.H.)
| | - Luiz O. F. Penalva
- Children’s Cancer Research Institute, UT Health San Antonio, San Antonio, TX 78229, USA; (M.B.); (C.Y.); (X.L.); (A.K.); (D.G.); (M.V.); (M.Q.); (P.R.A.); (T.D.)
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX 78229, USA
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11
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Zeng Z, Cao Z, Tang Y. Increased E2F2 predicts poor prognosis in patients with HCC based on TCGA data. BMC Cancer 2020; 20:1037. [PMID: 33115417 PMCID: PMC7594443 DOI: 10.1186/s12885-020-07529-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 10/15/2020] [Indexed: 02/07/2023] Open
Abstract
Background The E2F family of transcription factor 2 (E2F2) plays an important role in the development and progression of various tumors, but its association with hepatocellular carcinoma (HCC) remains unknown. Our study aimed to investigate the role and clinical significance of E2F2 in HCC. Methods HCC raw data were extracted from The Cancer Genome Atlas (TCGA). Wilcoxon signed-rank test, Kruskal-Wallis test and logistic regression were applied to analyze the relationship between the expression of E2F2 and clinicopathologic characteristics. Cox regression and Kaplan-Meier were employed to evaluate the correlation between clinicopathologic features and survival. The biological function of E2F2 was annotated by Gene Set Enrichment Analysis (GSEA). Results The expression of E2F2 was increased in HCC samples. The expression of elevated E2F2 in HCC samples was prominently correlated with histologic grade (OR = 2.62 for G3–4 vs. G1–2, p = 1.80E-05), clinical stage (OR = 1.74 for III-IV vs. I-II, p = 0.03), T (OR = 1.64 for T3–4 vs.T1–2, p = 0.04), tumor status (OR = 1.88 for with tumor vs. tumor free, p = 3.79E-03), plasma alpha fetoprotein (AFP) value (OR = 3.18 for AFP ≥ 400 vs AFP<20, p = 2.16E-04; OR = 2.50 for 20 ≤ AFP<400 vs AFP<20, p = 2.56E-03). Increased E2F2 had an unfavorable OS (p = 7.468e− 05), PFI (p = 3.183e− 05), DFI (p = 0.001), DSS (p = 4.172e− 05). Elevated E2F2 was independently bound up with OS (p = 0.004, hazard ratio [HR] = 2.4 (95% CI [1.3–4.2])), DFI (P = 0.029, hazard ratio [HR] = 2.0 (95% CI [1.1–3.7])) and PFI (P = 0.005, hazard ratio [HR] = 2.2 (95% CI [1.3–3.9])). GSEA disclosed that cell circle, RNA degradation, pyrimidine metabolism, base excision repair, aminoacyl tRNA biosynthesis, DNA replication, p53 signaling pathway, nucleotide excision repair, ubiquitin-mediated proteolysis, citrate cycle TCA cycle were notably enriched in E2F2 high expression phenotype. Conclusions Elevated E2F2 can be a promising independent prognostic biomarker and therapeutic target for HCC. Additionally, cell cycle, pyrimidine metabolism, DNA replication, p53 signaling pathway, ubiquitin-mediated proteolysis, the citrate cycle TCA cycle may be the key pathway by which E2F2 participates in the initial and progression of HCC.
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Affiliation(s)
- Zhili Zeng
- Guangzhou University of Chinese Medicine, Guangzhou, 510405, Guangdong, China
| | - Zebiao Cao
- Guangzhou University of Chinese Medicine, Guangzhou, 510405, Guangdong, China
| | - Ying Tang
- Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, no.12, Airport Road, Sanyuanli Street, Baiyun District, Guangzhou, 510405, Guangdong, China.
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12
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Huang T, Jiang C, Yang M, Xiao H, Huang X, Wu L, Yao M. Salmonella enterica serovar Typhimurium inhibits the innate immune response and promotes apoptosis in a ribosomal/TRP53-dependent manner in swine neutrophils. Vet Res 2020; 51:105. [PMID: 32854785 PMCID: PMC7450969 DOI: 10.1186/s13567-020-00828-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/10/2020] [Indexed: 01/08/2023] Open
Abstract
Neutrophils are the first barriers for resisting the invasion, proliferation, and damage caused by Salmonella Typhimurium. However, the mechanisms that control this resistance are not completely understood. In this study, we established an in vitro Salmonella infection model in porcine neutrophils, and analyzed the cellular transcriptome by deep sequencing and flow cytometry. The results showed that ribosomal gene transcription was inhibited, and two of these genes, RPL39 and RPL9, were related to TRP53 activation. Furthermore, several important innate immunity genes were also inhibited. Knock-down of RPL39 and RPL9 by siRNA caused an approximate fourfold up-regulation of TRP53. Knock-down of RPL39 and RPL9 also resulted in a significant down-regulation of IFNG and TNF, indicating an inhibition of the innate immune response. Silencing of RPL39 and RPL9 also resulted in the up-regulation of FAS, RB1, CASP6, and GADD45A, which play roles in cell cycle arrest and apoptosis. Neutrophils were either first treated with RPL39 siRNA, RPL9 siRNA, TRP53 activator, or TRP53 inhibitor, and then infected with Salmonella. Knock-down of RPL39 and RPL9, or treatment with TRP53 activator, can increase the intracellular proliferation of Salmonella in neutrophils. We speculate that much of the Salmonella virulence can be attributed to the enhancement of cell cycle arrest and the inhibition of the innate immune response, which allows the bacteria to successfully proliferate intracellularly.
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Affiliation(s)
- Tinghua Huang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Caiyun Jiang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Min Yang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Hong Xiao
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Xiali Huang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Lingbo Wu
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Min Yao
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China.
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13
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Lam HM, Nguyen HM, Labrecque MP, Brown LG, Coleman IM, Gulati R, Lakely B, Sondheim D, Chatterjee P, Marck BT, Matsumoto AM, Mostaghel EA, Schweizer MT, Nelson PS, Corey E. Durable Response of Enzalutamide-resistant Prostate Cancer to Supraphysiological Testosterone Is Associated with a Multifaceted Growth Suppression and Impaired DNA Damage Response Transcriptomic Program in Patient-derived Xenografts. Eur Urol 2019; 77:144-155. [PMID: 31227306 DOI: 10.1016/j.eururo.2019.05.042] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/30/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND Androgen deprivation therapy improves the survival of castration-resistant prostate cancer (CRPC) patients, yet ultimately fails with debilitating side effects. Supraphysiological testosterone (SPT)-based therapy produces clinical responses with improved quality of life in a subset of patients. Currently, no information defines a durable response to SPT. OBJECTIVE To identify key molecular phenotypes underlying SPT response to improve patient selection and guide combination treatment to achieve a durable response. DESIGN, SETTING, AND PARTICIPANTS A patient-derived xenograft (PDX) preclinical trial was performed with 13 CRPC PDXs to identify molecular features associated with SPT response. Comprehensive intratumoral androgen, tumor growth, and integrated transcriptomic and protein analyses were performed in three PDXs resistant to the newer androgen receptor (AR) pathway inhibitor enzalutamide (ENZ) to define SPT response and resistance. INTERVENTION Testosterone cypionate. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS SPT efficacy was evaluated by PDX growth, prostate-specific antigen (PSA) change, and survival. Intratumoral androgens were analyzed using mass spectrometry. Global transcriptome analysis was performed using RNA sequencing, and confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry. Log-rank and Mann-Whitney tests were used for survival and molecular analyses, respectively. RESULTS AND LIMITATIONS A durable SPT responder was identified, presenting robust repressions of ARv7 and E2F transcriptional outputs, and a DNA damage response (DDR) transcriptomic program that were altogether restored upon SPT resistance in the transient responder. ENZ rechallenge of SPT-relapsed PDXs resulted in PSA decreases but tumor progression. CONCLUSIONS SPT produces a durable response in AR-pathway inhibitor ENZ CRPC that is associated with sustained suppression of ARv7 and E2F transcriptional outputs, and the DDR transcriptome, highlighting the potential of combination treatments that maintain suppression of these programs to drive a durable response to SPT. PATIENT SUMMARY Patients with ENZ-resistant prostate cancer have very limited treatment options. Supraphysiological testosterone presents a prominent option for improved quality of life and a potential durable response in patients with sustained suppression on ARv7/E2F transcriptional outputs and DNA repair program.
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Affiliation(s)
- Hung-Ming Lam
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA; Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Macau (SAR), China
| | - Holly M Nguyen
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - Mark P Labrecque
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - Lisha G Brown
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - Ilsa M Coleman
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Roman Gulati
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Bryce Lakely
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - Daniel Sondheim
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - Payel Chatterjee
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Brett T Marck
- Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Alvin M Matsumoto
- Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA; Department of Medicine, Division of Medical Oncology, University of Washington, Seattle, WA, USA
| | - Elahe A Mostaghel
- Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; Department of Medicine, Division of Medical Oncology, University of Washington, Seattle, WA, USA
| | - Michael T Schweizer
- Department of Medicine, Division of Medical Oncology, University of Washington, Seattle, WA, USA; Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Peter S Nelson
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA; Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Department of Medicine, Division of Medical Oncology, University of Washington, Seattle, WA, USA
| | - Eva Corey
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA.
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14
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Ding N, Geng B, Li Z, Yang Q, Yan L, Wan L, Zhang B, Wang C, Xia Y. Fluid shear stress promotes osteoblast proliferation through the NFATc1-ERK5 pathway. Connect Tissue Res 2019; 60:107-116. [PMID: 29609502 DOI: 10.1080/03008207.2018.1459588] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Extracellular-regulated kinase 5 (ERK5) is thought to regulate osteoblast proliferation. To further understand how ERK5 signaling regulates osteoblast proliferation induced by fluid shear stress (FSS), we examined some potential signaling targets associated with ERK5 in MC3T3-E1 cells. METHODS MC3T3-E1 cells were treated with XMD8-92 (an ERK5 inhibitor) or Cyclosporin A (CsA, a nuclear factor of activated T cells (NFAT) c1 inhibitor) and/or exposed to 12 dyn/cm2 FSS. Phosphorylated-ERK5 (p-ERK5) and expression levels of NFATc1, ERK5, E2F2, and cyclin E1 were analyzed by western blot. The mRNA levels of genes associated with cell proliferation were analyzed by Polymerase Chain Reaction (PCR) array. Subcellular localization of p-ERK5 and NFATc1 were determined by immunofluorescence. Cell proliferation was evaluated by MTT assay. RESULTS NFATc1 expression was up-regulated by FSS. XMD8-92 only blocked ERK5 activation; however, CsA decreased NFATc1 and p-ERK5 levels, including after FSS stimulation. Exposure to NFATc1 inhibitor or ERK5 inhibitor resulted in decreased E2F2 and cyclin E1 expression and proliferation by proliferative MC3T3-E1 cells. Furthermore, immunofluorescence results illustrated that NFATc1 induced ERK5 phosphorylation, resulting in p-ERK5 translocation to the nucleus. CONCLUSIONS Our results reveal that NFATc1 acts as an intermediate to promote the phosphorylation of ERK5 induced by FSS. Moreover, activated NFATc1-ERK5 signaling up-regulates the expression of E2F2 and cyclin E1, which promote osteoblast proliferation.
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Affiliation(s)
- Ning Ding
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Bin Geng
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Zhonghao Li
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Quanzeng Yang
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Liang Yan
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Lang Wan
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Bo Zhang
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Cuifang Wang
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
| | - Yayi Xia
- a Department of Orthopaedics , Lanzhou University Second Hospital , Lanzhou , Gansu , China.,b Orthopaedics Key Laboratory of Gansu Province , Lanzhou , Gansu , China
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15
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Li Y, Huang D, Zheng L, Cao H, Gao Y, Yang Y, Fan Z. Retracted Article: Long non-coding RNA TUG1 alleviates high glucose induced podocyte inflammation, fibrosis and apoptosis in diabetic nephropathy via targeting the miR-27a-3p/E2F3 axis. RSC Adv 2019; 9:37620-37629. [PMID: 35542278 PMCID: PMC9075754 DOI: 10.1039/c9ra06136c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/01/2019] [Indexed: 12/12/2022] Open
Abstract
Diabetic nephropathy (DN) is the most common cause of end-stage renal disease (ESRD) in developed countries.
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Affiliation(s)
- Yang Li
- Department of Nephropathy and Rheumatology
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Denggao Huang
- Department of Central Lab
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Linlin Zheng
- Department of Central Lab
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Hui Cao
- Department of Central Lab
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Yuanhui Gao
- Department of Central Lab
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Yongmei Yang
- Department of Nephropathy and Rheumatology
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
| | - Zhongcheng Fan
- Department of Orthopedic
- Central South University Xiangya School of Medicine Affiliated Haikou Hospital
- Haikou
- China
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16
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Huang T, Huang X, Shi B, Wang F, Feng W, Yao M. Regulators of Salmonella-host interaction identified by peripheral blood transcriptome profiling: roles of TGFB1 and TRP53 in intracellular Salmonella replication in pigs. Vet Res 2018; 49:121. [PMID: 30541630 PMCID: PMC6292071 DOI: 10.1186/s13567-018-0616-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/29/2018] [Indexed: 02/07/2023] Open
Abstract
Peripheral blood transcriptome is an important intermediate data source for investigating the mechanism of Salmonella invasion, proliferation, and transmission. We challenged 4-week old piglets with Salmonella enterica serovar Typhimurium LT2 and investigated the peripheral blood gene expression profile before treatment (d0) and at 2 and 7 days post-inoculation (dpi) using deep sequencing. Regulator pathways were first predicted in silico and validated by wet-lab experiments. In total, 1255, 765, and 853 genes were differentially expressed between 2 dpi/d0, 7 dpi/d0, and 7 dpi/2 dpi, respectively. Additionally, 1333 genes showed a time effect during the investigated Salmonella infection period. Clustering analysis showed that the differentially expressed genes fell into six distinct expression clusters. Pathway annotation of these gene clusters showed that the innate immune system was first significantly upregulated at 2 dpi and then attenuated at 7 dpi. Toll-like receptor cascades, MyD88 cascade, phagosome pathway, cytokine signaling pathway, and lysosome pathway showed a similar expression pattern. Interestingly, we found that the ribosome pathway was significantly inhibited at 2 and 7 dpi. Gene expression regulation network enrichment analysis identified several candidate factors controlling the expression clusters. Further in vitro study showed that TGFB1 can inhibit Salmonella replication whereas TRP53 can promote Salmonella replication in porcine peripheral blood mononuclear cells and murine macrophages. These results provide new insights into the molecular mechanism of Salmonella-host interactions and clues for the genetic improvement of Salmonella infection resistance in pigs.
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Affiliation(s)
- Tinghua Huang
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Xiali Huang
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Bomei Shi
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Fangfang Wang
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Wenzhao Feng
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Min Yao
- College of Animal Science, Yangtze University, Jingzhou, 434025, Hubei, China.
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17
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Pellicano F, Park L, Hopcroft LEM, Shah MM, Jackson L, Scott MT, Clarke CJ, Sinclair A, Abraham SA, Hair A, Helgason GV, Aspinall-O'Dea M, Bhatia R, Leone G, Kranc KR, Whetton AD, Holyoake TL. hsa-mir183/EGR1-mediated regulation of E2F1 is required for CML stem/progenitor cell survival. Blood 2018; 131:1532-1544. [PMID: 29437554 PMCID: PMC6027092 DOI: 10.1182/blood-2017-05-783845] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 01/05/2018] [Indexed: 12/30/2022] Open
Abstract
Chronic myeloid leukemia (CML) stem/progenitor cells (SPCs) express a transcriptional program characteristic of proliferation, yet can achieve and maintain quiescence. Understanding the mechanisms by which leukemic SPCs maintain quiescence will help to clarify how they persist during long-term targeted treatment. We have identified a novel BCR-ABL1 protein kinase-dependent pathway mediated by the upregulation of hsa-mir183, the downregulation of its direct target early growth response 1 (EGR1), and, as a consequence, upregulation of E2F1. We show here that inhibition of hsa-mir183 reduced proliferation and impaired colony formation of CML SPCs. Downstream of this, inhibition of E2F1 also reduced proliferation of CML SPCs, leading to p53-mediated apoptosis. In addition, we demonstrate that E2F1 plays a pivotal role in regulating CML SPC proliferation status. Thus, for the first time, we highlight the mechanism of hsa-mir183/EGR1-mediated E2F1 regulation and demonstrate this axis as a novel, critical factor for CML SPC survival, offering new insights into leukemic stem cell eradication.
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MESH Headings
- Animals
- Cell Proliferation
- Cell Survival
- E2F1 Transcription Factor/biosynthesis
- E2F1 Transcription Factor/genetics
- Early Growth Response Protein 1/genetics
- Early Growth Response Protein 1/metabolism
- Female
- Gene Expression Regulation, Leukemic
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Male
- Mice, Knockout
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Signal Transduction
- Up-Regulation
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Affiliation(s)
- Francesca Pellicano
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Laura Park
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Lisa E M Hopcroft
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mansi M Shah
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Lorna Jackson
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mary T Scott
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Cassie J Clarke
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Amy Sinclair
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sheela A Abraham
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Alan Hair
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - G Vignir Helgason
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mark Aspinall-O'Dea
- Stem Cell and Leukaemia Proteomics Laboratory, Faculty Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Ravi Bhatia
- Division of Hematology and Oncology, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL
| | - Gustavo Leone
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC; and
| | - Kamil R Kranc
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Anthony D Whetton
- Stem Cell and Leukaemia Proteomics Laboratory, Faculty Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Tessa L Holyoake
- Paul O'Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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18
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Yang H, Wang L, Tang X, Bai W. miR-203a suppresses cell proliferation by targeting E2F transcription factor 3 in human gastric cancer. Oncol Lett 2017; 14:7687-7690. [PMID: 29344215 DOI: 10.3892/ol.2017.7199] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 02/01/2017] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRs) are a class of short non-coding RNAs that serve an essential role in the tumorigenesis of gastric cancer (GC). MiR-203a has been reported as a tumor repressor in various types of human cancer. In the present study, the function of miR-203a on the proliferation of GC cells was investigated. Bioinformatics analyses revealed that miR-203a targets the 3'-untranslated region of E2F transcription factor 3 (E2F3) messenger RNA. A luciferase reporter assay and western blot analysis were performed to confirm whether E2F3 was a target of miR-203a. The relative luciferase activity was decreased when overexpressing miR-203a with E2F3-wild type pmirGLO-3'-untranslated region vector, compared with the control group in HEK293 cells. Overexpression of miR-203a suppressed cell proliferation and colony formation of SGC-7901 and AGS GC cells. Inhibition of miR-203a promoted the proliferation of GC cells. Collectively, the results indicated that miR-203a may function as a tumor suppressor in GC by targeting E2F3.
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Affiliation(s)
- Huiqin Yang
- Respiratory Department, Traditional Chinese Medicine Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang Uygur Autonomous Region 830016, P.R. China
| | - Lixia Wang
- Respiratory Department, Traditional Chinese Medicine Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang Uygur Autonomous Region 830016, P.R. China
| | - Xiaoli Tang
- Respiratory Department, Traditional Chinese Medicine Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang Uygur Autonomous Region 830016, P.R. China
| | - Wenmei Bai
- Respiratory Department, Traditional Chinese Medicine Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang Uygur Autonomous Region 830016, P.R. China
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19
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Drosten M, Barbacid M. Ras and p53: An unsuspected liaison. Mol Cell Oncol 2016; 3:e996001. [PMID: 27308624 DOI: 10.1080/23723556.2014.996001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/03/2014] [Accepted: 12/04/2014] [Indexed: 12/30/2022]
Abstract
The precise mechanism by which Ras proteins mediate mitogenic signaling remains obscure. We have identified the p53/p21Cip1 axis as an essential component of the Ras mitogenic pathway. Moreover, cells carrying an inactive p53/p21Cip1/Rb pathway sustain cell proliferation by inducing retroactivation of the MAPK signaling cascade in a Ras-independent manner.
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Affiliation(s)
- Matthias Drosten
- Molecular Oncology Program; Centro Nacional de Investigaciones Oncológicas (CNIO) ; Madrid, Spain
| | - Mariano Barbacid
- Molecular Oncology Program; Centro Nacional de Investigaciones Oncológicas (CNIO) ; Madrid, Spain
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20
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Huntington JT, Tang X, Kent LN, Schmidt CR, Leone G. The Spectrum of E2F in Liver Disease--Mediated Regulation in Biology and Cancer. J Cell Physiol 2016; 231:1438-49. [PMID: 26566968 DOI: 10.1002/jcp.25242] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 11/03/2015] [Indexed: 12/11/2022]
Abstract
Uncoordinated cell growth is one of the fundamental concepts in carcinogenesis and occurs secondary to dysregulation of the cell cycle. The E2Fs are a large family of transcription factors and are key regulators of the cell cycle. The activation of E2Fs is intimately regulated by retinoblastoma 1 (RB1). The RB pathway has been implicated in almost every human malignancy. Recently there have been exciting developments in the E2F field using animal models to better understand the role of E2Fs in vivo. Genetic mouse models have proven essential in implicating E2Fs in hepatocellular carcinoma (HCC) and liver disease. In this review, the general structure and function of E2Fs as well as the role for E2Fs in the development of HCC and liver disease is evaluated. Specifically, what is known about E2Fs in human disease is explored in depth, and future directions are discussed.
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Affiliation(s)
- Justin T Huntington
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xing Tang
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, Columbus, Ohio.,Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio.,Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Lindsey N Kent
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, Columbus, Ohio.,Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio.,Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Carl R Schmidt
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Gustavo Leone
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, Columbus, Ohio.,Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio.,Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
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21
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Wang T, Mu L, Jin H, Zhang P, Wang Y, Ma X, Pan J, Miao J, Yuan Y. The effects of bufadienolides on HER2 overexpressing breast cancer cells. Tumour Biol 2015; 37:7155-63. [DOI: 10.1007/s13277-015-4381-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/04/2015] [Indexed: 10/22/2022] Open
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22
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Cellular transformation of mouse embryo fibroblasts in the absence of activator E2Fs. J Virol 2015; 89:5124-33. [PMID: 25717106 DOI: 10.1128/jvi.03578-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/18/2015] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED The E2F family of transcription factors, broadly divided into activator and repressor E2Fs, regulates cell cycle genes. Current models indicate that activator E2Fs are necessary for cell cycle progression and tumorigenesis and are also required to mediate transformation induced by DNA tumor viruses. E2Fs are negatively regulated by the retinoblastoma (RB) family of tumor suppressor proteins, and virus-encoded oncogenes disrupt the RB-E2F repressor complexes. This results in the release of activator E2Fs and induction of E2F-dependent genes. In agreement, expression of large tumor T antigens (TAg) encoded by polyomaviruses in mammalian cells results in increased transcriptional levels of E2F target genes. In addition, tumorigenesis induced by transgenic expression of simian virus 40 (SV40) TAg in choroid plexus or intestinal villi requires at least one activator E2F. In contrast, we show that SV40 TAg-induced transformation in mouse embryonic fibroblasts is independent of activator E2Fs. This work, coupled with recent studies showing that proliferation in stem and progenitor cells is independent of activator E2Fs, suggests the presence of parallel pathways governing cell proliferation and tumorigenesis. IMPORTANCE The RB-E2F pathway is altered in many cancers and is also targeted by DNA tumor viruses. Viral oncoprotein action on RBs results in the release of activator E2Fs and upregulation of E2F target genes; thus, activator E2Fs are considered essential for normal and tumorigenic cell proliferation. However, we have observed that SV40 large T antigen can induce cell proliferation and transformation in the absence of activator E2Fs. Our results also suggest that TAg action on pRBs regulates both E2F-dependent and -independent pathways that govern proliferation. Thus, specific cell proliferation pathways affected by RB alterations in cancer may be a factor in tumor behavior and response to therapy.
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23
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Iglesias-Ara A, Zenarruzabeitia O, Buelta L, Merino J, Zubiaga AM. E2F1 and E2F2 prevent replicative stress and subsequent p53-dependent organ involution. Cell Death Differ 2015; 22:1577-89. [PMID: 25656653 DOI: 10.1038/cdd.2015.4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/19/2014] [Accepted: 01/06/2015] [Indexed: 11/09/2022] Open
Abstract
Tissue homeostasis requires tight regulation of cellular proliferation, differentiation and apoptosis. E2F1 and E2F2 transcription factors share a critical role in tissue homeostasis, since their combined inactivation results in overall organ involution, specially affecting the pancreatic gland, which subsequently triggers diabetes. We have examined the mechanism by which these E2Fs regulate tissue homeostasis. We show that pancreas atrophy in E2F1/E2F2 double-knockout (DKO) mice is associated with mitochondrial apoptosis and activation of the p53 pathway in young animals, before the development of diabetes. A deregulated expression of E2F target genes was detected in pancreatic cells of young DKO animals, along with unscheduled DNA replication and activation of a DNA damage response. Importantly, suppression of DNA replication in vivo with aphidicolin led to a significant inhibition of the p53 pathway in DKO pancreas, implying a causal link between DNA replication stress and p53 activation in this model. We further show that activation of the p53 pathway has a key role in the aberrant phenotype of DKO mice, since targeted inactivation of p53 gene abrogated cellular apoptosis and prevented organ involution and insulin-dependent diabetes in mice lacking E2F1/E2F2. Unexpectedly, p53 inactivation unmasked oncogenic features of E2F1/E2F2-depleted cells, as evidenced by an accelerated tumor development in triple-knockout mice compared with p53(-/-) mice. Collectively, our data reveal a role for E2F1 and E2F2 as suppressors of replicative stress in differentiating cells, and uncover the existence of a robust E2F-p53 regulatory axis to enable tissue homeostasis and prevent tumorigenesis. These findings have implications in the design of approaches targeting E2F for cancer therapy.
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Affiliation(s)
- A Iglesias-Ara
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, Bilbao, Spain
| | - O Zenarruzabeitia
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, Bilbao, Spain
| | - L Buelta
- University of Cantabria-IDIVAL, Cantabria, Spain
| | - J Merino
- University of Cantabria-IDIVAL, Cantabria, Spain
| | - A M Zubiaga
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, Bilbao, Spain
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24
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Iwasaki T, Tanaka K, Kawano M, Itonaga I, Tsumura H. Tumor-suppressive microRNA-let-7a inhibits cell proliferation via targeting of E2F2 in osteosarcoma cells. Int J Oncol 2015; 46:1543-50. [PMID: 25647078 DOI: 10.3892/ijo.2015.2867] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/12/2015] [Indexed: 11/06/2022] Open
Abstract
MicroRNAs (miRNAs) regulate cell proliferation and differentiation by silencing gene expression at the post-transcriptional level; moreover, by binding to the complementary sequences within mRNAs in cancer cells, these small non-coding RNA molecules can function as tumor suppressors or oncogenes. Recently, the dysregulation of miRNA expression has been found to be associated with increased tumorigenicity and poor prognosis in several cancer types, including osteosarcoma (OS). To identify potential oncogenic factors in OS, we analyzed changes in the expression profile of miRNAs and its downstream mRNAs in five OS cell lines and human mesenchymal stem cells (hMSCs) by a microarray-based approach. The expression of an miRNA-let‑7a was significantly downregulated and E2F2 was significantly upregulated in all tested OS cells compared with hMSCs. When let-7a was transfected into OS cell lines, the expression of E2F2 in the cells was greatly suppressed, suggesting that E2F2 is a target of miRNA-let-7a in OS cells. The transfection of let-7a further inhibited cell cycle progression and proliferation of OS cells. In addition, let-7a overexpression in OS cells significantly suppressed the tumor growth in vivo. The present study demonstrates the novel mechanism that regulates E2F2 expression via miRNA-let-7a in OS cells. Because E2F2 is pivotal in promoting cell growth through the regulation of several genes, our results might facilitate the development of new therapeutic targets for the treatment of OS.
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Affiliation(s)
- Tatsuya Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Kazuhiro Tanaka
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Masanori Kawano
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Ichiro Itonaga
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Hiroshi Tsumura
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
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25
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Dittrich A, Gautrey H, Browell D, Tyson-Capper A. The HER2 Signaling Network in Breast Cancer--Like a Spider in its Web. J Mammary Gland Biol Neoplasia 2014; 19:253-70. [PMID: 25544707 DOI: 10.1007/s10911-014-9329-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/14/2014] [Indexed: 12/21/2022] Open
Abstract
The human epidermal growth factor receptor 2 (HER2) is a major player in the survival and proliferation of tumour cells and is overexpressed in up to 30 % of breast cancer cases. A considerable amount of work has been undertaken to unravel the activity and function of HER2 to try and develop effective therapies that impede its action in HER2 positive breast tumours. Research has focused on exploring the HER2 activated phosphoinositide-3-kinase (PI3K)/AKT and rat sarcoma/mitogen-activated protein kinase (RAS/MAPK) pathways for therapies. Despite the advances, cases of drug resistance and recurrence of disease still remain a challenge to overcome. An important aspect for drug resistance is the complexity of the HER2 signaling network. This includes the crosstalk between HER2 and hormone receptors; its function as a transcription factor; the regulation of HER2 by protein-tyrosine phosphatases and a complex network of positive and negative feedback-loops. This review summarises the current knowledge of many different HER2 interactions to illustrate the complexity of the HER2 network from the transcription of HER2 to the effect of its downstream targets. Exploring the novel avenues of the HER2 signaling could yield a better understanding of treatment resistance and give rise to developing new and more effective therapies.
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Affiliation(s)
- A Dittrich
- Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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26
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Loss of p53 induces cell proliferation via Ras-independent activation of the Raf/Mek/Erk signaling pathway. Proc Natl Acad Sci U S A 2014; 111:15155-60. [PMID: 25288756 DOI: 10.1073/pnas.1417549111] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The Ras family of small GTPases constitutes a central node in the transmission of mitogenic stimuli to the cell cycle machinery. The ultimate receptor of these mitogenic signals is the retinoblastoma (Rb) family of pocket proteins, whose inactivation is a required step to license cell proliferation. However, little is known regarding the molecular events that connect Ras signaling with the cell cycle. Here, we provide genetic evidence to illustrate that the p53/p21 Cdk-interacting protein 1 (Cip1)/Rb axis is an essential component of the Ras signaling pathway. Indeed, knockdown of p53, p21Cip1, or Rb restores proliferative properties in cells arrested by ablation of the three Ras loci, H-, N- and K-Ras. Ras signaling selectively inactivates p53-mediated induction of p21Cip1 expression by inhibiting acetylation of specific lysine residues in the p53 DNA binding domain. Proliferation of cells lacking both Ras proteins and p53 can be prevented by reexpression of the human p53 ortholog, provided that it retains an active DNA binding domain and an intact lysine residue at position 164. These results unveil a previously unidentified role for p53 in preventing cell proliferation under unfavorable mitogenic conditions. Moreover, we provide evidence that cells lacking Ras and p53 proteins owe their proliferative properties to the unexpected retroactivation of the Raf/Mek/Erk cascade by a Ras-independent mechanism.
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27
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Chang YC, Hsiao YM, Wu MF, Ou CC, Lin YW, Lue KH, Ko JL. Interruption of lung cancer cell migration and proliferation by fungal immunomodulatory protein FIP-fve from Flammulina velutipes. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:12044-12052. [PMID: 24274472 DOI: 10.1021/jf4030272] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
FIP-fve is an immunomodulatory protein isolated from Flammulina velutipes that possesses anti-inflammatory and immunomodulatory activities. However, little is known about its anticancer effects. It is suppressed cell proliferation of A549 lung cancer cells on MTT assay following 48 h treatment of FIP-fve. FIP-fve treatment also resulted in cell cycle arrest but not apoptosis on flow cytometry. This immunomodulatory protein was observed to increase p53 expression, as well as the expression of its downstream gene p21, on Western blot. FIP-fve inhibited migration of A549 cells on wound healing assay and decreased filopodia fiber formation on labeling with Texas Red-X phalloidin. To confirm the effect of FIP-fve on the role of Rac1 in filopodia formation, we investigated the activity of Rac1 in A549 cells following FIP-fve treatment. FIP-fve inhibited EGF-induced activation of Rac1. We demonstrated that FIP-fve decreases RACGAP1 mRNA and protein levels on RT-PCR and Western blot. In addition, the reporter activity of RACGAP1 was reduced by FIP-fve on RacGAP1 promoter assay. Silencing of RacGAP1 decreased cell migration, and overexpression of RacGAP1 increased cell migration in A549 cells. In conclusion, FIP-fve inhibits lung cancer cell migration via RacGAP1 and suppresses the proliferation of A549 via p53 activation pathway.
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Affiliation(s)
- Yu-Chi Chang
- Institute of Medicine, Chung Shan Medical University , No. 110, Sec. 1, Chien-Kuo N. Road, Taichung 40203, Taiwan
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28
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Selective roles of E2Fs for ErbB2- and Myc-mediated mammary tumorigenesis. Oncogene 2013; 34:119-28. [PMID: 24276244 PMCID: PMC4032808 DOI: 10.1038/onc.2013.511] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/23/2013] [Accepted: 10/25/2013] [Indexed: 11/08/2022]
Abstract
Previous studies have demonstrated that cyclin D1, an upstream regulator of the Rb/E2F pathway, is an essential component of the ErbB2/Ras (but not the Wnt/Myc) oncogenic pathway in the mammary epithelium. However, the role of specific E2fs for ErbB2/Ras-mediated mammary tumorigenesis remains unknown. Here, we show that in the majority of mouse and human primary mammary carcinomas with ErbB2/HER2 overexpression, E2f3a is up-regulated, raising the possibility that E2F3a is a critical effector of the ErbB2 oncogenic signaling pathway in the mammary gland. We examined the consequence of ablating individual E2fs in mice on ErbB2-triggered mammary tumorigenesis in comparison to a comparable Myc-driven mammary tumor model. We found that loss of E2f1 or E2f3 led to a significant delay in tumor onset in both oncogenic models, whereas loss of E2f2 accelerated mammary tumorigenesis driven by Myc-overexpression. Furthermore, southern blot analysis of final tumors derived from conditionally deleted E2f3(-/loxP) mammary glands revealed that there is a selection against E2f3(-/-) cells from developing mammary carcinomas, and that such selection pressure is higher in the presence of ErbB2 activation than in the presence of Myc activation. Taken together, our data suggest oncogenic activities of E2F1 and E2F3 in ErbB2- or Myc-triggered mammary tumorigenesis, and a tumor suppressor role of E2F2 in Myc-mediated mammary tumorigenesis.
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29
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Liu B, Cong R, Peng B, Zhu B, Dou G, Ai H, Zhang X, Wang Z, Xu X. CtIP is required for DNA damage-dependent induction of P21. Cell Cycle 2013; 13:90-5. [PMID: 24196441 PMCID: PMC3925741 DOI: 10.4161/cc.26810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA endonuclease CtIP is involved in both DNA double-strand break (DSB) repair and transcriptional repression/activation. The cyclin-dependent kinase inhibitor P21, which is induced at transcription level in response to a variety of stresses, controls G₁/S transition. In this report, we found that CtIP bound to the P21 promoter, and this binding was enhanced in response to DNA damage. Concomitantly, ectopic expression of CtIP increased P21 promoter activity, and this increment was enhanced upon camptothecin treatment. Conversely, DNA damage failed to induce P21 gene expression in CtIP-deficient cells. Taken together, our data demonstrate that CtIP is required for DNA damage-induced P21 induction.
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Affiliation(s)
- Bo Liu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Rixin Cong
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Bin Peng
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Bingtao Zhu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Gelin Dou
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Haiyan Ai
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Xiaodong Zhang
- College of Life Sciences; Wuhan University; Wuhan, Hubei, China
| | - Zhenghe Wang
- Department of Genetics and Case Comprehensive Cancer Center; Case Western Reserve University; Cleveland, OH USA
| | - Xingzhi Xu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
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30
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Zhou BR, Guo XF, Zhang JA, Xu Y, Li W, Wu D, Yin ZQ, Permatasari F, Luo D. Elevated miR-34c-5p mediates dermal fibroblast senescence by ultraviolet irradiation. Int J Biol Sci 2013; 9:743-52. [PMID: 23983607 PMCID: PMC3753410 DOI: 10.7150/ijbs.5345] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 07/23/2013] [Indexed: 01/17/2023] Open
Abstract
Previous studies showed that several miRNAs can regulate pathways involved in UVB-induced premature senescence and response to ultraviolet irradiation. It has also been reported that miR-34c-5p may be involved in senescence-related mechanisms. We propose that miR-34c-5p may play a crucial role in senescence of normal human primary dermal fibroblasts. Here, we explored the roles of miR-34c-5p in UVB-induced premature senescence on dermal fibroblasts. MiR-34c-5p expression was increased in dermal fibroblasts after repeated subcytotoxic UVB treatments. Underexpression of miR-34c-5p in dermal fibroblasts led to a marked delay of many senescent phenotypes induced by repeated UVB treatments. Furthermore, underexpression of miR-34c-5p in dermal fibroblasts can antagonize the alteration of G1-arrested fibroblasts. Moreover, E2F3, which can inactivate p53 pathway and play a role in cell cycle progression, is a down-stream target of miR-34c-5p. Forced down-expression of miR-34c-5p decreased the expression of UVB-SIPS induced P21 and P53 at both mRNA and protein levels. Our data demonstrated that down-regulation of miR-34c-5p can protect human primary dermal fibroblasts from UVB-induced premature senescence via regulations of some senescence-related molecules.
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Affiliation(s)
- Bing-rong Zhou
- Department of Dermatology, the First Affiliated Hospital of Nanjing Medical University, Guangzhou road 300#, Nanjing, Jiangsu province, China PR
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31
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Chen CL, Tsukamoto H, Liu JC, Kashiwabara C, Feldman D, Sher L, Dooley S, French SW, Mishra L, Petrovic L, Jeong JH, Machida K. Reciprocal regulation by TLR4 and TGF-β in tumor-initiating stem-like cells. J Clin Invest 2013; 123:2832-49. [PMID: 23921128 DOI: 10.1172/jci65859] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 04/08/2013] [Indexed: 12/17/2022] Open
Abstract
Tumor-initiating stem-like cells (TICs) are resistant to chemotherapy and associated with hepatocellular carcinoma (HCC) caused by HCV and/or alcohol-related chronic liver injury. Using HCV Tg mouse models and patients with HCC, we isolated CD133(+) TICs and identified the pluripotency marker NANOG as a direct target of TLR4, which drives the tumor-initiating activity of TICs. These TLR4/NANOG-dependent TICs were defective in the TGF-β tumor suppressor pathway. Functional oncogene screening of a TIC cDNA library identified Yap1 and Igf2bp3 as NANOG-dependent genes that inactivate TGF-β signaling. Mechanistically, we determined that YAP1 mediates cytoplasmic retention of phosphorylated SMAD3 and suppresses SMAD3 phosphorylation/activation by the IGF2BP3/AKT/mTOR pathway. Silencing of both YAP1 and IGF2BP3 restored TGF-β signaling, inhibited pluripotency genes and tumorigenesis, and abrogated chemoresistance of TICs. Mice with defective TGF-β signaling (Spnb2(+/-) mice) exhibited enhanced liver TLR4 expression and developed HCC in a TLR4-dependent manner. Taken together, these results suggest that the activated TLR4/NANOG oncogenic pathway is linked to suppression of cytostatic TGF-β signaling and could potentially serve as a therapeutic target for HCV-related HCC.
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Affiliation(s)
- Chia-Lin Chen
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California, USA
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Li M, Yu M, Liu C, Zhu H, He X, Peng S, Hua J. miR-34c works downstream of p53 leading to dairy goat male germline stem-cell (mGSCs) apoptosis. Cell Prolif 2013; 46:223-31. [PMID: 23510477 DOI: 10.1111/cpr.12013] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 10/21/2012] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Recent lines of evidence have indicated that miR-34c can play important roles in regulation of the cell cycle, cell senescence and apoptosis of mouse and human tumour cells, spermatogenesis, and male germ-cell apoptosis. However, there is little information on the effects of miR-34c on proliferation and apoptosis of livestock male germ cells. The dairy goat is a convenient domestic species for biological investigation and application. The purpose of this study was to investigate the effects of miR-34c on apoptosis and proliferation of dairy goat male germline stem cells (mGSCs), as well as to determine the relationship between p53 and miR-34c in this species. MATERIALS AND METHODS Morphological observation, miRNA in situ hybridisation (ISH), bromodeoxyuridine staining, flow cytometry, quantitative-RT-PCR (Q-RT-PCR) and western blotting were utilized to ascertain apoptosis and proliferation of mGSCs, through transfection of miR-34c mimics (miR-34c), miR-34c inhibitor (anti-miR-34c), miR-34c mimics and inhibitors co-transfected (mixture) compared to control groups. RESULTS Results manifested that miR-34c over-expression promoted mGSCs apoptosis and suppressed their proliferation. Simultaneously, a variety of apoptosis-related gene expression was increased while some proliferation-related genes were downregulated. Accordingly, miR-34c promoted apoptosis in mGSCs and reduced their proliferation; moreover, expression of miR-34c was p53-dependent. CONCLUSIONS This study is the first to provide a model for study of miRNAs and mechanisms of proliferation and apoptosis in male dairy goat germ cells.
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Affiliation(s)
- M Li
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering & Technology, Key Lab for Animal Biotechnology of Agriculture Ministry, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Herriges JC, Yi L, Hines EA, Harvey JF, Xu G, Gray P, Ma Q, Sun X. Genome-scale study of transcription factor expression in the branching mouse lung. Dev Dyn 2012; 241:1432-53. [PMID: 22711520 PMCID: PMC3529173 DOI: 10.1002/dvdy.23823] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2012] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Mammalian lung development consists of a series of precisely choreographed events that drive the progression from simple lung buds to the elaborately branched organ that fulfills the vital function of gas exchange. Strict transcriptional control is essential for lung development. Among the large number of transcription factors encoded in the mouse genome, only a small portion of them are known to be expressed and function in the developing lung. Thus a systematic investigation of transcription factors expressed in the lung is warranted. RESULTS To enrich for genes that may be responsible for regional growth and patterning, we performed a screen using RNA in situ hybridization to identify genes that show restricted expression patterns in the embryonic lung. We focused on the pseudoglandular stage during which the lung undergoes branching morphogenesis, a cardinal event of lung development. Using a genome-scale probe set that represents over 90% of the transcription factors encoded in the mouse genome, we identified 62 transcription factor genes with localized expression in the epithelium, mesenchyme, or both. Many of these genes have not been previously implicated in lung development. CONCLUSIONS Our findings provide new starting points for the elucidation of the transcriptional circuitry that controls lung development.
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Affiliation(s)
- John C. Herriges
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Lan Yi
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Elizabeth A. Hines
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Julie F. Harvey
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Guoliang Xu
- Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China 200031
| | - Paul Gray
- Department of Anatomy and Neurobiology, Washington University, St. Louis, MO 63110
| | - Qiufu Ma
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Xin Sun
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
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MicroRNAs as a novel cellular senescence regulator. Ageing Res Rev 2012; 11:41-50. [PMID: 21689787 DOI: 10.1016/j.arr.2011.06.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/09/2011] [Accepted: 06/02/2011] [Indexed: 12/26/2022]
Abstract
Cellular senescence is a program activated in normal cells in response to various types of stresses and is manifested by permanent arrest of cell cycle. Cellular senescence is closely related to tumor suppression, and may contribute to the ageing of organisms. The complex senescence cell phenotype has many different mechanisms. Recent studies have provided important insights regarding the role played by miRNAs during cellular senescence as a novel molecular mechanism. In this article, we will review the latest advances in the identification and validation of senescence-regulatory miRNAs and the possible mechanisms.
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Epstein-Barr virus downregulates microRNA 203 through the oncoprotein latent membrane protein 1: a contribution to increased tumor incidence in epithelial cells. J Virol 2011; 86:3088-99. [PMID: 22205737 DOI: 10.1128/jvi.05901-11] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Epstein-Barr virus (EBV) is highly associated with nasopharyngeal carcinoma (NPC), and it regulates some microRNAs (miRNAs) that are involved in the development of cancer. The role of EBV in the deregulation of cellular miRNAs and how this affects the progression of NPC remain to be investigated. An analysis of the miRNA profile in an EBV-infected cell line revealed that miRNA 203 (miR-203) was downregulated. miR-203 is expressed specifically in epithelial cells. This downregulation of miR-203 was further verified and functionally analyzed. miR-203 was downregulated substantially in epithelial cells and NPC tissues that were latently infected with EBV. Downregulation of miR-203 also occurred during the early stage of EBV infection. Furthermore, the viral oncoprotein, latent membrane protein 1 (LMP1), was responsible for downregulation of miR-203. Removal of the latent EBV genome or suppression of LMP1 resulted in restoration of miR-203 expression. EBV-LMP1 mediated the downregulation of miR-203 at the primary transcript level. E2F3 and CCNG1 were identified as target genes of miR-203. Ectopic expression of miR-203 inhibited EBV-induced S-phase entry and transformation in vivo. Overexpression of the targets overcame the effects of miR-203 mimics on the cell cycle, and the expression of target genes in tumor models was inhibited by miR-203. Inhibitors of Jun N-terminal protein kinase (JNK) and NF-κB blocked miR-203 downregulation. These results imply that EBV promotes malignancy by downregulating cellular miR-203, which contributes to the etiology of NPC.
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Westendorp B, Mokry M, Groot Koerkamp MJA, Holstege FCP, Cuppen E, de Bruin A. E2F7 represses a network of oscillating cell cycle genes to control S-phase progression. Nucleic Acids Res 2011; 40:3511-23. [PMID: 22180533 PMCID: PMC3333892 DOI: 10.1093/nar/gkr1203] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
E2F transcription factors are known to be important for timely activation of G1/S and G2/M genes required for cell cycle progression, but transcriptional mechanisms for deactivation of cell cycle-regulated genes are unknown. Here, we show that E2F7 is highly expressed during mid to late S-phase, occupies promoters of G1/S-regulated genes and represses their transcription. ChIP-seq analysis revealed that E2F7 binds preferentially to genomic sites containing the TTCCCGCC motif, which closely resembles the E2F consensus site. We identified 89 target genes that carry E2F7 binding sites close to the transcriptional start site and that are directly repressed by short-term induction of E2F7. Most of these target genes are known to be activated by E2Fs and are involved in DNA replication, metabolism and DNA repair. Importantly, induction of E2F7 during G0-G1/S resulted in S-phase arrest and DNA damage, whereas expression of E2F7 during G2/M failed to disturb cell cycle progression. These findings provide strong evidence that E2F7 directly controls the downswing of oscillating G1/S genes during S-phase progression.
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Affiliation(s)
- Bart Westendorp
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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37
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Feng B, Wang R, Song HZ, Chen LB. MicroRNA-200b reverses chemoresistance of docetaxel-resistant human lung adenocarcinoma cells by targeting E2F3. Cancer 2011; 118:3365-76. [PMID: 22139708 DOI: 10.1002/cncr.26560] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/26/2011] [Accepted: 08/15/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND MicroRNAs (miRNAs) have been identified as important posttranscriptional regulators involved in various biological and pathological processes of cells, but their association with tumor chemoresistance has not been fully understood. METHODS We detected miRNA-200b (miR-200b) expression in different lung adenocarcinoma cell lines and then focused on its roles in regulation of docetaxel chemoresistance. We also identified E2F3 as a novel target of miR-200b. RESULTS Based on miRNA microarray data, miR-200b was identified as the most down-regulated miRNA in docetaxel-resistant SPC-A1/DTX cells compared with parental SPC-A1 cells. Ectopic miR-200b expression reversed docetaxel chemoresistance of lung adenocarcinoma cells through cell proliferation inhibition, apoptosis enhancement, and G(2) /M cell cycle arrest. In a nude mouse xenograft model, up-regulation of miR-200b significantly enhanced response of SPC-A1/DTX cells to docetaxel. Luciferase reporters containing the 3' untranslated region sequence of E2F3 messenger RNA were used to demonstrate that miR-200b could directly target E2F3. Small interfering RNA-mediated E2F3 knockdown revealed similar effects as that of ectopic miR-200b expression. Decreased miR-200b expression was also detected in tumor tissues sampled from lung adenocarcinoma patients treated with docetaxel-based chemotherapy and was proved to be correlated with high expression of E2F3, decreased sensitivity to docetaxel, and poor prognosis. CONCLUSIONS Our results suggest that down-regulation of miR-200b could lead to E2F3 overexpression and in turn contribute to chemoresistance of lung adenocarcinoma cells to docetaxel.
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Affiliation(s)
- Bing Feng
- Department of Medical Oncology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
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Refinement of the genetics of the host response to Salmonella infection in MOLF/Ei: regulation of type 1 IFN and TRP3 pathways by Ity2. Genes Immun 2011; 13:175-83. [PMID: 21956657 DOI: 10.1038/gene.2011.69] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Typhoid fever, which is caused by Salmonella typhi and paratyphi, is a severe systemic disease that remains a major public health issue in several areas of the world. We can model the human disease using mice infected with a related bacterium, Salmonella typhimurium. This model recapitulates several clinical aspects of the human disease and allows for the study of the host response to Salmonella typhimurium infection in vivo. Previous work in our laboratory has identified three Immunity to typhimurium loci (Ity, Ity2 and Ity3) in the wild-derived MOLF/Ei mice, influencing survival after infection with Salmonella typhimurium. The MOLF/Ei alleles at Ity and Ity2 are protective, while the MOLF/Ei allele at Ity3 confers susceptibility. In this paper, we have generated a novel cross combination between the highly susceptible strain, MOLF/Ei, and the resistant strain, 129S6, to better define the genetic architecture of susceptibility to infection in MOLF/Ei. Using this cross, we have replicated the locus on chr 11 (Ity2) and identified a novel locus on chr 13 (Ity13). Using microarrays and transcriptional profiling, we examined the response of uninfected and infected Ity2 congenic mice. These analyses demonstrate a role for both type-1-interferon (IFN) and TRP53 signaling in the pathogenesis of Salmonella infection.
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Wong JV, Dong P, Nevins JR, Mathey-Prevot B, You L. Network calisthenics: control of E2F dynamics in cell cycle entry. Cell Cycle 2011; 10:3086-94. [PMID: 21900750 DOI: 10.4161/cc.10.18.17350] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Stimulation of quiescent mammalian cells with mitogens induces an abrupt increase in E2F1-3 expression just prior to the onset of DNA synthesis, followed by a rapid decline as replication ceases. This temporal adaptation in E2F facilitates a transient pattern of gene expression that reflects the ordered nature of DNA replication. The challenge to understand how E2F dynamics coordinate molecular events required for high-fidelity DNA replication has great biological implications. Indeed, precocious, prolonged, elevated or reduced accumulation of E2F can generate replication stress that culminates in either arrest or death. Accordingly, temporal characteristics of E2F are regulated by several network modules that include feedforward and autoregulatory loops. In this review, we discuss how these network modules contribute to "shaping" E2F dynamics in the context of mammalian cell cycle entry.
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Affiliation(s)
- Jeffrey V Wong
- Department of Biomedical Engineering, Institute for Genome Sciences and Policy, Duke University, Durham, NC, USA.
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40
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Wang M, Lei Y. Delaying vascular aging with Chinese medicine: implications from an overview of the p53 and miR-34s family. Chin J Integr Med 2011; 17:635-9. [PMID: 21826600 DOI: 10.1007/s11655-011-0823-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Indexed: 12/15/2022]
Abstract
p53 is an important target for studying vascular aging. However, as people gradually learned more about the miR-34s and the relationship between miR-34s and p53, new research idea emerged. This paper tries to elaborate the feature of p53, microRNA and miR-34s in-depth, analyze the regulatory action of miR-34s on p53, and offer some new prevention and treatment prospects about vascular aging in Chinese medicine.
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Affiliation(s)
- Ming Wang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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41
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Wenzel PL, Chong JL, Sáenz-Robles MT, Ferrey A, Hagan JP, Gomez YM, Rajmohan R, Sharma N, Chen HZ, Pipas JM, Robinson ML, Leone G. Cell proliferation in the absence of E2F1-3. Dev Biol 2010; 351:35-45. [PMID: 21185283 DOI: 10.1016/j.ydbio.2010.12.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 12/06/2010] [Accepted: 12/15/2010] [Indexed: 01/09/2023]
Abstract
E2F transcription factors regulate the progression of the cell cycle by repression or transactivation of genes that encode cyclins, cyclin dependent kinases, checkpoint regulators, and replication proteins. Although some E2F functions are independent of the Retinoblastoma tumor suppressor (Rb) and related family members, p107 and p130, much of E2F-mediated repression of S phase entry is dependent upon Rb. We previously showed in cultured mouse embryonic fibroblasts that concomitant loss of three E2F activators with overlapping functions (E2F1, E2F2, and E2F3) triggered the p53-p21(Cip1) response and caused cell cycle arrest. Here we report on a dramatic difference in the requirement for E2F during development and in cultured cells by showing that cell cycle entry occurs normally in E2f1-3 triply-deficient epithelial stem cells and progenitors of the developing lens. Sixteen days after birth, however, massive apoptosis in differentiating epithelium leads to a collapse of the entire eye. Prior to this collapse, we find that expression of cell cycle-regulated genes in E2F-deficient lenses is aberrantly high. In a second set of experiments, we demonstrate that E2F3 ablation alone does not cause abnormalities in lens development but rescues phenotypic defects caused by loss of Rb, a binding partner of E2F known to recruit histone deacetylases, SWI/SNF and CtBP-polycomb complexes, methyltransferases, and other co-repressors to gene promoters. Together, these data implicate E2F1-3 in mediating transcriptional repression by Rb during cell cycle exit and point to a critical role for their repressive functions in cell survival.
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Affiliation(s)
- Pamela L Wenzel
- Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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42
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Ouyang N, Ke S, Eagleton N, Xie Y, Chen G, Laffins B, Yao H, Zhou B, Tian Y. Pregnane X receptor suppresses proliferation and tumourigenicity of colon cancer cells. Br J Cancer 2010; 102:1753-61. [PMID: 20531417 PMCID: PMC2883694 DOI: 10.1038/sj.bjc.6605677] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 03/29/2010] [Accepted: 03/31/2010] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Pregnane X receptor (PXR) is a nuclear receptor that regulates the metabolism and disposition of various xenobiotics and endobioitics. We investigated a novel PXR function in regulating colon tumourigenesis in this study. METHODS Histochemistry, transfection, cell proliferation assay, anchorage-alpha-dependent assay, xenograft, immunohistochemistry, immunofluorescence flow cytometry. RESULTS Using histochemistry analysis, we found that PXR expressions were lost or greatly diminished in many colon tumours. Ectopic expression of human PXR through stable transfection of PXR into colon cancer cell line HT29 significantly inhibited cell proliferation as determined by cell proliferation assay and anchorage-independent assay. Pregnane X receptor suppressed significantly HT29 xenograft tumour growth in nude mice compared with control (310+/-6.2 vs 120+/-6 mg, P<0.01). Immunohistochemistry and immunofluorescence analysis of Ki-67 on excised xenograft tumour tissues showed that PXR inhibited cancer cell proliferation. Furthermore, expressions of PXR and Ki-67 were mutually exclusive. The flow cytometry analysis indicated that PXR caused G(0)/G(1) cell-cycle arrest. p21(WAF1/CIP1) expression was markedly elevated whereas E2F1 expression was inhibited by PXR. CONCLUSION PXR inhibits the proliferation and tumourigenicity of colon cancer cells by controlling cell cycle at G(0)/G(1) cell phase by regulating p21(WAF1/CIP1) and E2F/Rb pathways.
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Affiliation(s)
- N Ouyang
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - S Ke
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - N Eagleton
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Y Xie
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - G Chen
- The First Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
| | - B Laffins
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - H Yao
- Chemotherapy Department, Sun Yet-Sen Memorial Hospital, Guangzhou, China
| | - B Zhou
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Y Tian
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
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miR-34s—a tumor suppression protein p53 highly related microRNA. YI CHUAN = HEREDITAS 2010; 32:423-30. [DOI: 10.3724/sp.j.1005.2010.00423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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44
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Boqué N, Campión J, Milagro FI, Moreno-Aliaga MJ, Martinez JA. Some cyclin-dependent kinase inhibitors-related genes are regulated by vitamin C in a model of diet-induced obesity. Biol Pharm Bull 2010; 32:1462-8. [PMID: 19652391 DOI: 10.1248/bpb.32.1462] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this research was to investigate differential gene expression of cyclin-dependent kinase inhibitors (CKIs) in white adipose tissue (WAT) and liver from high-fat fed male Wistar rats with or without vitamin C (VC) supplementation (750 mg/kg of body weight). After 56 d of experimentation, animals fed on a cafeteria diet increased significantly body weights and total body fat. Reverse transcription-polymerase chain reaction (RT-PCR) studies showed that cafeteria diet decreased p21 and p57 mRNA expression in subcutaneous WAT and increased p21 mRNA in liver. Overall, these data provide new information about the role of high fat intake on mRNA levels of several CKIs with implications in adipogenesis, cell metabolism and weight homeostasis. Interestingly, VC supplementation partially prevented diet-induced adiposity and increased p27 mRNA in liver without any changes in the other tissues and genes analyzed. Thus, hepatic mRNA changes induced by ascorbic acid indicate a possible role of these genes in diet-induced oxidative stress processes.
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Affiliation(s)
- Noemí Boqué
- Institute of Nutrition and Food Science, University of Navarra, Pamplona, Spain
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45
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Chong JL, Wenzel PL, Sáenz-Robles MT, Nair V, Ferrey A, Hagan JP, Gomez YM, Sharma N, Chen HZ, Ouseph M, Wang SH, Trikha P, Culp B, Mezache L, Winton DJ, Sansom OJ, Chen D, Bremner R, Cantalupo PG, Robinson ML, Pipas JM, Leone G. E2f1-3 switch from activators in progenitor cells to repressors in differentiating cells. Nature 2010; 462:930-4. [PMID: 20016602 PMCID: PMC2806193 DOI: 10.1038/nature08677] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 11/17/2009] [Indexed: 01/20/2023]
Abstract
In the classic paradigm of mammalian cell cycle control, Rb functions to restrict cells from entering S phase by sequestering E2F activators (E2f1, E2f2 and E2f3), which are invariably portrayed as the ultimate effectors of a transcriptional program that commit cells to enter and progress through S phase1, 2. Using a panel of tissue-specific cre-transgenic mice and conditional E2f alleles we examine the effects of E2f1, E2f2 and E2f3 triple deficiency in murine ES cells, embryos and small intestines. We show that in normal dividing progenitor cells E2F1-3 function as transcriptional activators, but contrary to current dogma, are dispensable for cell division and instead are necessary for cell survival. In differentiating cells they function in complex with Rb as repressors to silence E2F targets and facilitate exit from the cell cycle. The inactivation of Rb in differentiating cells resulted in a switch of E2F1-3 from repressors to activators, leading to the superactivation of E2F responsive targets and ectopic cell divisions, and loss of E2f1-3 completely suppressed these phenotypes. This work contextualizes the activator versus repressor functions of E2F1-3 in vivo, revealing distinct roles in dividing versus differentiating cells and in normal versus cancer-like cell cycles in vivo.
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Affiliation(s)
- Jean-Leon Chong
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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Chen D, Pacal M, Wenzel P, Knoepfler PS, Leone G, Bremner R. Division and apoptosis of E2f-deficient retinal progenitors. Nature 2010; 462:925-9. [PMID: 20016601 DOI: 10.1038/nature08544] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 09/25/2009] [Indexed: 12/16/2022]
Abstract
The activating E2f transcription factors (E2f1, E2f2 and E2f3) induce transcription and are widely viewed as essential positive cell cycle regulators. Indeed, they drive cells out of quiescence, and the 'cancer cell cycle' in Rb1 null cells is E2f-dependent. Absence of activating E2fs in flies or mammalian fibroblasts causes cell cycle arrest, but this block is alleviated by removing repressive E2f or the tumour suppressor p53, respectively. Thus, whether activating E2fs are indispensable for normal division is an area of debate. Activating E2fs are also well known pro-apoptotic factors, providing a defence against oncogenesis, yet E2f1 can limit irradiation-induced apoptosis. In flies this occurs through repression of hid (also called Wrinkled; Smac/Diablo in mammals). However, in mammals the mechanism is unclear because Smac/Diablo is induced, not repressed, by E2f1, and in keratinocytes survival is promoted indirectly through induction of DNA repair targets. Thus, a direct pro-survival function for E2f1-3 and/or its relevance beyond irradiation has not been established. To address E2f1-3 function in normal cells in vivo we focused on the mouse retina, which is a relatively simple central nervous system component that can be manipulated genetically without compromising viability and has provided considerable insight into development and cancer. Here we show that unlike fibroblasts, E2f1-3 null retinal progenitor cells or activated Müller glia can divide. We attribute this effect to functional interchangeability with Mycn. However, loss of activating E2fs caused downregulation of the p53 deacetylase Sirt1, p53 hyperacetylation and elevated apoptosis, establishing a novel E2f-Sirt1-p53 survival axis in vivo. Thus, activating E2fs are not universally required for normal mammalian cell division, but have an unexpected pro-survival role in development.
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Affiliation(s)
- Danian Chen
- Toronto Western Research Institute, University Health Network, Department of Ophthalmology, and Laboratory Medicine and Pathobiology, University of Toronto, Ontario M5T 2S8, Canada
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Almeida MQ, Muchow M, Boikos S, Bauer AJ, Griffin KJ, Tsang KM, Cheadle C, Watkins T, Wen F, Starost MF, Bossis I, Nesterova M, Stratakis CA. Mouse Prkar1a haploinsufficiency leads to an increase in tumors in the Trp53+/- or Rb1+/- backgrounds and chemically induced skin papillomas by dysregulation of the cell cycle and Wnt signaling. Hum Mol Genet 2010; 19:1387-98. [PMID: 20080939 DOI: 10.1093/hmg/ddq014] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
PRKAR1A inactivation leads to dysregulated cAMP signaling and Carney complex (CNC) in humans, a syndrome associated with skin, endocrine and other tumors. The CNC phenotype is not easily explained by the ubiquitous cAMP signaling defect; furthermore, Prkar1a(+/-) mice did not develop skin and other CNC tumors. To identify whether a Prkar1a defect is truly a generic but weak tumorigenic signal that depends on tissue-specific or other factors, we investigated Prkar1a(+/-) mice when bred within the Rb1(+/-) or Trp53(+/-) backgrounds, or treated with a two-step skin carcinogenesis protocol. Prkar1a(+/-) Trp53(+/-) mice developed more sarcomas than Trp53(+/-) mice (P < 0.05) and Prkar1a(+/-) Rb1(+/-) mice grew more (and larger) pituitary and thyroid tumors than Rb1(+/-) mice. All mice with double heterozygosity had significantly reduced life-spans compared with their single-heterozygous counterparts. Prkar1a(+/-) mice also developed more papillomas than wild-type animals. A whole-genome transcriptome profiling of tumors produced by all three models identified Wnt signaling as the main pathway activated by abnormal cAMP signaling, along with cell cycle abnormalities; all changes were confirmed by qRT-PCR array and immunohistochemistry. siRNA down-regulation of Ctnnb1, E2f1 or Cdk4 inhibited proliferation of human adrenal cells bearing a PRKAR1A-inactivating mutation and Prkar1a(+/-) mouse embryonic fibroblasts and arrested both cell lines at the G0/G1 phase of the cell cycle. In conclusion, Prkar1a haploinsufficiency is a relatively weak tumorigenic signal that can act synergistically with other tumor suppressor gene defects or chemicals to induce tumors, mostly through Wnt-signaling activation and cell cycle dysregulation, consistent with studies in human neoplasms carrying PRKAR1A defects.
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Affiliation(s)
- Madson Q Almeida
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice KennedyShriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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Cdk2 and Cdk4 regulate the centrosome cycle and are critical mediators of centrosome amplification in p53-null cells. Mol Cell Biol 2009; 30:694-710. [PMID: 19933848 DOI: 10.1128/mcb.00253-09] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The two mitotic centrosomes direct spindle bipolarity to maintain euploidy. Centrosome amplification-the acquisition of > or =3 centrosomes-generates multipolar mitoses, aneuploidy, and chromosome instability to promote cancer biogenesis. While much evidence suggests that Cdk2 is the major conductor of the centrosome cycle and that it mediates centrosome amplification induced by various altered tumor suppressors, the role played by Cdk4 in a normal or deregulated centrosome cycle is unknown. Using a gene knockout approach, we report that Cdk2 and Cdk4 are critical to the centrosome cycle, since centrosome separation and duplication are premature in Cdk2(-)(/)(-) mouse embryonic fibroblasts (MEFs) and are compromised in Cdk4(-)(/)(-) MEFs. Additionally, ablation of Cdk4 or Cdk2 abrogates centrosome amplification and chromosome instability in p53-null MEFs. Absence of Cdk2 or Cdk4 prevents centrosome amplification by abrogating excessive centriole duplication. Furthermore, hyperactive Cdk2 and Cdk4 deregulate the licensing of the centrosome duplication cycle in p53-null cells by hyperphosphorylating nucleophosmin (NPM) at Thr199, as evidenced by observations that ablation of Cdk2, Cdk4, or both Cdk2 and Cdk4 abrogates that excessive phosphorylation. Since a mutant form of NPM lacking the G(1) Cdk phosphorylation site (NPM(T199A)) prevents centrosome amplification to the same extent as ablation of Cdk2 or Cdk4, we conclude that the Cdk2/Cdk4/NPM pathway is a major guardian of centrosome dysfunction and genomic integrity.
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Abstract
Mutations of the retinoblastoma tumour suppressor gene (RB1) or components regulating the RB pathway have been identified in almost every human malignancy. The E2F transcription factors function in cell cycle control and are intimately regulated by RB. Studies of model organisms have revealed conserved functions for E2Fs during development, suggesting that the cancer-related proliferative roles of E2F family members represent a recent evolutionary adaptation. However, given that some human tumours have concurrent RB1 inactivation and E2F amplification and overexpression, we propose that there are alternative tumour-promoting activities for the E2F family, which are independent of cell cycle regulation.
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Affiliation(s)
- Hui-Zi Chen
- Human Cancer Genetics Program, Department of Molecular Virology, Immunology and Medical Genetics and Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210, USA
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Abstract
During tumour development cells sustain mutations that disrupt normal mechanisms controlling proliferation. Remarkably, the Rb-E2f and MDM2-p53 pathways are both defective in most, if not all, human tumours, which underscores the crucial role of these pathways in regulating cell cycle progression and viability. A simple interpretation of the observation that both pathways are deregulated is that they function independently in the control of cell fate. However, a large body of evidence indicates that, in addition to their independent effects on cell fate, there is extensive crosstalk between these two pathways, and specifically between the transcription factors E2F1 and p53, which influences vital cellular decisions. This Review discusses the molecular mechanisms that underlie the intricate interactions between E2f and p53.
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Affiliation(s)
- Shirley Polager
- The Mina and Everard Goodman Faculty of Life Science, Bar Ilan University, Ramat Gan 52900, Israel
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