1
|
Kumari P, Beeraka NM, Tengli A, Bannimath G, Baath RK, Patil M. Recent Updates on Oncogenic Signaling of Aurora Kinases in Chemosensitive, Chemoresistant Cancers: Novel Medicinal Chemistry Approaches for Targeting Aurora Kinases. Curr Med Chem 2024; 31:3502-3528. [PMID: 37138483 DOI: 10.2174/0929867330666230503124408] [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: 11/28/2022] [Revised: 02/02/2023] [Accepted: 02/27/2023] [Indexed: 05/05/2023]
Abstract
The Aurora Kinase family (AKI) is composed of serine-threonine protein kinases involved in the modulation of the cell cycle and mitosis. These kinases are required for regulating the adherence of hereditary-related data. Members of this family can be categorized into aurora kinase A (Ark-A), aurora kinase B (Ark-B), and aurora kinase C (Ark-C), consisting of highly conserved threonine protein kinases. These kinases can modulate cell processes such as spindle assembly, checkpoint pathway, and cytokinesis during cell division. The main aim of this review is to explore recent updates on the oncogenic signaling of aurora kinases in chemosensitive/chemoresistant cancers and to explore the various medicinal chemistry approaches to target these kinases. We searched Pubmed, Scopus, NLM, Pubchem, and Relemed to obtain information pertinent to the updated signaling role of aurora kinases and medicinal chemistry approaches and discussed the recently updated roles of each aurora kinases and their downstream signaling cascades in the progression of several chemosensitive/chemoresistant cancers; subsequently, we discussed the natural products (scoulerine, Corynoline, Hesperidin Jadomycin-B, fisetin), and synthetic, medicinal chemistry molecules as aurora kinase inhibitors (AKIs). Several natural products' efficacy was explained as AKIs in chemosensitization and chemoresistant cancers. For instance, novel triazole molecules have been used against gastric cancer, whereas cyanopyridines are used against colorectal cancer and trifluoroacetate derivatives could be used for esophageal cancer. Furthermore, quinolone hydrazine derivatives can be used to target breast cancer and cervical cancer. In contrast, the indole derivatives can be preferred to target oral cancer whereas thiosemicarbazone-indole could be used against prostate cancer, as reported in an earlier investigation against cancerous cells. Moreover, these chemical derivatives can be examined as AKIs through preclinical studies. In addition, the synthesis of novel AKIs through these medicinal chemistry substrates in the laboratory using in silico and synthetic routes could be beneficial to develop prospective novel AKIs to target chemoresistant cancers. This study is beneficial to oncologists, chemists, and medicinal chemists to explore novel chemical moiety synthesis to target specifically the peptide sequences of aurora kinases in several chemoresistant cancer cell types.
Collapse
Affiliation(s)
- Pooja Kumari
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| | - Narasimha Murthy Beeraka
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
- Department of Human Anatomy, I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya str., Moscow 119991, Russia
| | - Anandkumar Tengli
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| | - Gurupadayya Bannimath
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| | - Ramandeep Kaur Baath
- Department of Pharmaceautics, IFTM University, Lodhipur Rajput, NH-24 Delhi Road, Moradabad 244102, Uttar Pradesh, India
| | - Mayuri Patil
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| |
Collapse
|
2
|
Zhao H, Jia P, Nanding K, Wu M, Bai X, Morigen M, Fan L. Lysophosphatidic acid suppresses apoptosis of high-grade serous ovarian cancer cells by inducing autophagy activity and promotes cell-cycle progression via EGFR-PI3K/Aurora-A Thr288-geminin dual signaling pathways. Front Pharmacol 2022; 13:1046269. [PMID: 36601056 PMCID: PMC9806123 DOI: 10.3389/fphar.2022.1046269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
Lysophosphatidic acid (LPA) and geminin are overexpressed in ovarian cancer, and increasing evidence supports their contribution to ovarian tumor development. Here, we reveal that geminin depletion induces autophagy suppression and enhances reactive oxygen species (ROS) production and apoptosis of high-grade serous ovarian cancer (HGSOC) cells. Bioinformatics analysis and pharmacological inhibition studies confirm that LPA activates geminin expression in the early S phase in HGSOC cells via the LPAR1/3/MMPs/EGFR/PI3K/mTOR pathway. Furthermore, LPA phosphorylates Aurora-A kinase on Thr288 through EGFR transactivation, and this event potentiates additional geminin stabilization. In turn, overexpressed and stabilized geminin regulates DNA replication, cell-cycle progression, and cell proliferation of HGSOC cells. Our data provide potential targets for enhancing the clinical benefit of HGSOC precision medicine.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Lifei Fan
- Inner Mongolia Key Laboratory for Molecular Regulation of the Cell, State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| |
Collapse
|
3
|
Cacioppo R, Lindon C. Regulating the regulator: a survey of mechanisms from transcription to translation controlling expression of mammalian cell cycle kinase Aurora A. Open Biol 2022; 12:220134. [PMID: 36067794 PMCID: PMC9448500 DOI: 10.1098/rsob.220134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/11/2022] [Indexed: 11/12/2022] Open
Abstract
Aurora Kinase A (AURKA) is a positive regulator of mitosis with a strict cell cycle-dependent expression pattern. Recently, novel oncogenic roles of AURKA have been uncovered that are independent of the kinase activity and act within multiple signalling pathways, including cell proliferation, survival and cancer stem cell phenotypes. For this, cellular abundance of AURKA protein is per se crucial and must be tightly fine-tuned. Indeed, AURKA is found overexpressed in different cancers, typically as a result of gene amplification or enhanced transcription. It has however become clear that impaired processing, decay and translation of AURKA mRNA can also offer the basis for altered AURKA levels. Accordingly, the involvement of gene expression mechanisms controlling AURKA expression in human diseases is increasingly recognized and calls for much more research. Here, we explore and create an integrated view of the molecular processes regulating AURKA expression at the level of transcription, post-transcription and translation, intercalating discussion on how impaired regulation underlies disease. Given that targeting AURKA levels might affect more functions compared to inhibiting the kinase activity, deeper understanding of its gene expression may aid the design of alternative and therapeutically more successful ways of suppressing the AURKA oncogene.
Collapse
Affiliation(s)
- Roberta Cacioppo
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Catherine Lindon
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| |
Collapse
|
4
|
Du R, Huang C, Liu K, Li X, Dong Z. Targeting AURKA in Cancer: molecular mechanisms and opportunities for Cancer therapy. Mol Cancer 2021; 20:15. [PMID: 33451333 PMCID: PMC7809767 DOI: 10.1186/s12943-020-01305-3] [Citation(s) in RCA: 234] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/29/2020] [Indexed: 12/24/2022] Open
Abstract
Aurora kinase A (AURKA) belongs to the family of serine/threonine kinases, whose activation is necessary for cell division processes via regulation of mitosis. AURKA shows significantly higher expression in cancer tissues than in normal control tissues for multiple tumor types according to the TCGA database. Activation of AURKA has been demonstrated to play an important role in a wide range of cancers, and numerous AURKA substrates have been identified. AURKA-mediated phosphorylation can regulate the functions of AURKA substrates, some of which are mitosis regulators, tumor suppressors or oncogenes. In addition, enrichment of AURKA-interacting proteins with KEGG pathway and GO analysis have demonstrated that these proteins are involved in classic oncogenic pathways. All of this evidence favors the idea of AURKA as a target for cancer therapy, and some small molecules targeting AURKA have been discovered. These AURKA inhibitors (AKIs) have been tested in preclinical studies, and some of them have been subjected to clinical trials as monotherapies or in combination with classic chemotherapy or other targeted therapies.
Collapse
Affiliation(s)
- Ruijuan Du
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China. .,China-US (Henan) Hormel Cancer Institute, No. 127, Dongming Road, Jinshui District, Zhengzhou, 450008, Henan, China.
| | - Chuntian Huang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.,China-US (Henan) Hormel Cancer Institute, No. 127, Dongming Road, Jinshui District, Zhengzhou, 450008, Henan, China
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.,China-US (Henan) Hormel Cancer Institute, No. 127, Dongming Road, Jinshui District, Zhengzhou, 450008, Henan, China.,The Collaborative Innovation Center of Henan Province for Cancer Chemoprevention, Zhengzhou, China.,State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, Henan, China
| | - Xiang Li
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China. .,China-US (Henan) Hormel Cancer Institute, No. 127, Dongming Road, Jinshui District, Zhengzhou, 450008, Henan, China. .,The Collaborative Innovation Center of Henan Province for Cancer Chemoprevention, Zhengzhou, China. .,State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, Henan, China.
| | - Zigang Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China. .,China-US (Henan) Hormel Cancer Institute, No. 127, Dongming Road, Jinshui District, Zhengzhou, 450008, Henan, China. .,The Collaborative Innovation Center of Henan Province for Cancer Chemoprevention, Zhengzhou, China. .,State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, Henan, China. .,College of medicine, Zhengzhou University, Zhengzhou, 450001, Henan, China.
| |
Collapse
|
5
|
Asangani I, Blair IA, Van Duyne G, Hilser VJ, Moiseenkova-Bell V, Plymate S, Sprenger C, Wand AJ, Penning TM. Using biochemistry and biophysics to extinguish androgen receptor signaling in prostate cancer. J Biol Chem 2021; 296:100240. [PMID: 33384381 PMCID: PMC7949100 DOI: 10.1074/jbc.rev120.012411] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 12/19/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022] Open
Abstract
Castration resistant prostate cancer (CRPC) continues to be androgen receptor (AR) driven. Inhibition of AR signaling in CRPC could be advanced using state-of-the-art biophysical and biochemical techniques. Structural characterization of AR and its complexes by cryo-electron microscopy would advance the development of N-terminal domain (NTD) and ligand-binding domain (LBD) antagonists. The structural basis of AR function is unlikely to be determined by any single structure due to the intrinsic disorder of its NTD, which not only interacts with coregulators but likely accounts for the constitutive activity of AR-splice variants (SV), which lack the LBD and emerge in CRPC. Using different AR constructs lacking the LBD, their effects on protein folding, DNA binding, and transcriptional activity could reveal how interdomain coupling explains the activity of AR-SVs. The AR also interacts with coregulators that promote chromatin looping. Elucidating the mechanisms involved can identify vulnerabilities to treat CRPC, which do not involve targeting the AR. Phosphorylation of the AR coactivator MED-1 by CDK7 is one mechanism that can be blocked by the use of CDK7 inhibitors. CRPC gains resistance to AR signaling inhibitors (ARSI). Drug resistance may involve AR-SVs, but their role requires their reliable quantification by SILAC-mass spectrometry during disease progression. ARSI drug resistance also occurs by intratumoral androgen biosynthesis catalyzed by AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase), which is unique in that its acts as a coactivator of AR. Novel bifunctional inhibitors that competitively inhibit AKR1C3 and block its coactivator function could be developed using reverse-micelle NMR and fragment-based drug discovery.
Collapse
Affiliation(s)
- Irfan Asangani
- Department Cancer Biology, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ian A Blair
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gregory Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Vincent J Hilser
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Vera Moiseenkova-Bell
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen Plymate
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, and GRECC, Seattle, Washington, USA
| | - Cynthia Sprenger
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, and GRECC, Seattle, Washington, USA
| | - A Joshua Wand
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, USA
| | - Trevor M Penning
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
6
|
Identifying Cancer Specific Driver Modules Using a Network-Based Method. Molecules 2018; 23:molecules23051114. [PMID: 29738475 PMCID: PMC6100049 DOI: 10.3390/molecules23051114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/26/2018] [Accepted: 05/07/2018] [Indexed: 02/01/2023] Open
Abstract
Detecting driver modules is a key challenge for understanding the mechanisms of carcinogenesis at the pathway level. Identifying cancer specific driver modules is helpful for interpreting the different principles of different cancer types. However, most methods are proposed to identify driver modules in one cancer, but few methods are introduced to detect cancer specific driver modules. We propose a network-based method to detect cancer specific driver modules (CSDM) in a certain cancer type to other cancer types. We construct the specific network of a cancer by combining specific coverage and mutual exclusivity in all cancer types, to catch the specificity of the cancer at the pathway level. To illustrate the performance of the method, we apply CSDM on 12 TCGA cancer types. When we compare CSDM with SpeMDP and HotNet2 with regard to specific coverage and the enrichment of GO terms and KEGG pathways, CSDM is more accurate. We find that the specific driver modules of two different cancers have little overlap, which indicates that the driver modules detected by CSDM are specific. Finally, we also analyze three specific driver modules of BRCA, BLCA, and LAML intersecting with well-known pathways. The source code of CSDM is freely accessible at https://github.com/fengli28/CSDM.git.
Collapse
|
7
|
Yang TY, Teng CLJ, Lin TCC, Chen KC, Hsu SL, Wu CC. Transcriptional repression of Aurora-A gene by wild-type p53 through directly binding to its promoter with histone deacetylase 1 and mSin3a. Int J Cancer 2017; 142:92-108. [PMID: 28884479 DOI: 10.1002/ijc.31035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/06/2017] [Accepted: 08/21/2017] [Indexed: 01/18/2023]
Abstract
In this study, we firstly showed that p53 transcriptionally represses Aurora-A gene expression through directly binding to its promoter. DNA affinity precipitation assay and chromatin immunoprecipitation assay indicated that p53 physically bound to the Aurora-A promoter. Moreover, the in vitro and in vivo assays showed that p53 directly bound to the Aurora-A promoter together with histone deacetylase 1 (HDAC1) and mSin3a as corepressors. Furthermore, we identified that the nucleotides -360 to -354 (CCTGCCC), upstream of the Aurora-A transcriptional start site, was responsible for the p53-mediated repression. Mutation within this site disrupted its interaction with p53, mSin3a and HDAC1, as well as attenuated the repressive effect of p53 on Aurora-A promoter activity. Treatment with trichostatin A (TSA), a HDAC1 inhibitor, disrupted the interaction of p53-HDAC1-mSin3a complex with the nucleotides -365∼-345 region, and enhanced the Aurora-A promoter activity and gene expression. Additionally, knockdown of p53 or mSin3a also drastically blocked the formation of p53-HDAC1-mSin3a repressive complex onto this promoter region and elevated the Aurora-A promoter activity and gene expression. Moreover, the p53-HDAC1-mSin3a repressive complex also involved in the inhibition of Aurora-A gene expression upon cisplatin treatment. Finally, the clinical investigation showed that Aurora-A and p53 exhibited an inverse correlation in both the expression level and prognostic status, and the low p53/high Aurora-A showed the poorest prognosis of NSCLC patients. Our findings showed novel regulatory mechanisms of p53 in regulating Aurora-A gene expression in NSCLC cells.
Collapse
Affiliation(s)
- Tsung-Ying Yang
- Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, 407, Taiwan, Republic of China
| | - Chieh-Lin Jerry Teng
- Division of Hematology/Medical Oncology, Department of Medicine, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.,Department of Life Science, Tunghai University, Taichung, Taiwan, Republic of China.,Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Tsung-Chieh Chester Lin
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Linkou, Taiwan, Republic of China
| | - Kun-Chieh Chen
- Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, 407, Taiwan, Republic of China
| | - Shih-Lan Hsu
- Department of Education & Research, Taichung Veterans General Hospital, Taichung, 407, Taiwan, Republic of China
| | - Chun-Chi Wu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China.,Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan, Republic of China
| |
Collapse
|
8
|
Grinchuk OV, Motakis E, Yenamandra SP, Ow GS, Jenjaroenpun P, Tang Z, Yarmishyn AA, Ivshina AV, Kuznetsov VA. Sense-antisense gene-pairs in breast cancer and associated pathological pathways. Oncotarget 2016; 6:42197-221. [PMID: 26517092 PMCID: PMC4747219 DOI: 10.18632/oncotarget.6255] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 09/30/2015] [Indexed: 01/04/2023] Open
Abstract
More than 30% of human protein-coding genes form hereditary complex genome architectures composed of sense-antisense (SA) gene pairs (SAGPs) transcribing their RNAs from both strands of a given locus. Such architectures represent important novel components of genome complexity contributing to gene expression deregulation in cancer cells. Therefore, the architectures might be involved in cancer pathways and, in turn, be used for novel drug targets discovery. However, the global roles of SAGPs in cancer pathways has not been studied. Here we investigated SAGPs associated with breast cancer (BC)-related pathways using systems biology, prognostic survival and experimental methods. Gene expression analysis identified 73 BC-relevant SAGPs that are highly correlated in BC. Survival modelling and metadata analysis of the 1161 BC patients allowed us to develop a novel patient prognostic grouping method selecting the 12 survival-significant SAGPs. The qRT-PCR-validated 12-SAGP prognostic signature reproducibly stratified BC patients into low- and high-risk prognostic subgroups. The 1381 SAGP-defined differentially expressed genes common across three studied cohorts were identified. The functional enrichment analysis of these genes revealed the GABPA gene network, including BC-relevant SAGPs, specific gene sets involved in cell cycle, spliceosomal and proteasomal pathways. The co-regulatory function of GABPA in BC cells was supported using siRNA knockdown studies. Thus, we demonstrated SAGPs as the synergistically functional genome architectures interconnected with cancer-related pathways and associated with BC patient clinical outcomes. Taken together, SAGPs represent an important component of genome complexity which can be used to identify novel aspects of coordinated pathological gene networks in cancers.
Collapse
Affiliation(s)
- Oleg V Grinchuk
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Efthymios Motakis
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore.,Current address: RIKEN, Japan
| | - Surya Pavan Yenamandra
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Ghim Siong Ow
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Piroon Jenjaroenpun
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Zhiqun Tang
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Aliaksandr A Yarmishyn
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Anna V Ivshina
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Vladimir A Kuznetsov
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore.,School of Computing Engineering, Nanyang Technological University, Singapore
| |
Collapse
|
9
|
Yin JW, Wang G. The Mediator complex: a master coordinator of transcription and cell lineage development. Development 2014; 141:977-87. [PMID: 24550107 DOI: 10.1242/dev.098392] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mediator is a multiprotein complex that is required for gene transcription by RNA polymerase II. Multiple subunits of the complex show specificity in relaying information from signals and transcription factors to the RNA polymerase II machinery, thus enabling control of the expression of specific genes. Recent studies have also provided novel mechanistic insights into the roles of Mediator in epigenetic regulation, transcriptional elongation, termination, mRNA processing, noncoding RNA activation and super enhancer formation. Based on these specific roles in gene regulation, Mediator has emerged as a master coordinator of development and cell lineage determination. Here, we describe the most recent advances in understanding the mechanisms of Mediator function, with an emphasis on its role during development and disease.
Collapse
Affiliation(s)
- Jing-wen Yin
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | | |
Collapse
|
10
|
Abstract
The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module.
Collapse
Affiliation(s)
- Zachary C Poss
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, CO , USA
| | | | | |
Collapse
|
11
|
Zhu LJ, Yan WX, Chen ZW, Chen Y, Chen D, Zhang TH, Liao GQ. Disruption of mediator complex subunit 19 (Med19) inhibits cell growth and migration in tongue cancer. World J Surg Oncol 2013; 11:116. [PMID: 23705783 PMCID: PMC3673833 DOI: 10.1186/1477-7819-11-116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 05/09/2013] [Indexed: 12/15/2022] Open
Abstract
Background Mediator complex subunit 19 (Med19) is a critical subunit of the mediator complex that forms a bridge between the transcription factors and RNA polymerase II. Although it has been reported that Med19 plays an important role in stabilizing the whole mediator complex, its biological importance in tongue cancer cell proliferation and migration has not been addressed. Methods By using MTT, BrdU incorporation, colony formation, flow cytometric, tumorigenesis and transwell assays, We tested the Med19 role on tongue cancer cell growth and migration. Results We demonstrated that lentivirus-mediated Med19 knockdown could arrest tongue cancer cells at G1 phase, inhibit tongue cancer cell proliferation and migration in vitro. The tumorigenicity of Med19 short hairpin RNA (shRNA)-expressing lentivirus infected tongue cancer cells were decreased after inoculating into nude mice. Conclusions These results indicate that Med19 plays an important role in tongue cancer proliferation and migration, and suggest possible applications for tongue cancer therapy.
Collapse
Affiliation(s)
- Li-Jun Zhu
- Department of Oral and Maxillofacial Surgery, Guanghua College of Stomatology, Sun Yat-Sen University, 56 Lingyuanxi Road, Guangzhou 510055, China
| | | | | | | | | | | | | |
Collapse
|
12
|
Wu CC, Yang TY, Yu CTR, Phan L, Ivan C, Sood AK, Hsu SL, Lee MH. p53 negatively regulates Aurora A via both transcriptional and posttranslational regulation. Cell Cycle 2012; 11:3433-42. [PMID: 22894933 DOI: 10.4161/cc.21732] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
p53 plays an important role in mitotic checkpoint, but what its role is remains enigmatic. Aurora A is a Ser/Thr kinase involved in correcting progression of mitosis. Here, we show that p53 is a negative regulator for Aurora A. We found that p53 deficiency leads to Aurora A elevation. Ectopic expression of p53 or DNA damage-induced expression of p53 can suppress the expression of Aurora A. Mechanistic studies show that p53 is a negative regulator for Aurora A expression through both transcriptional and posttranslational regulation. p53 knockdown in cancer cells reduces the level of p21, which, in turn, increases the activity of CDK2 followed by induction of Rb1 hyperphosphorylation and its dissociation with transcriptional factor E2F3. E2F3 can bind to Aurora A gene promoter, potentiating Aurora A gene expression and p53 deficiency, enhancing the binding of E2F3 on Aurora A promoter. Also, p53 deficiency leads to decelerating Aurora A's turnover rate, due to the fact that p53 deficiency causes the downregulation of Fbw7α, a component of E3 ligase of Aurora A. Consistently, p53 knockdown-mediated Aurora A elevation is mitigated when Fbw7α is ectopically expressed. Thus, p53-mediated Aurora A degradation requires Fbw7α expression. Significantly, inverse correlation between p53 and Aurora A elevation is translated into the deregulation of centrosome amplification. p53 knockdown leads to high percentages of cells with abnormal amplification of centrosome. These data suggest that p53 is an important negative regulator of Aurora A, and that loss of p53 in many types of cancer could lead to abnormal elevation of Aurora A and dysregulated mitosis, which provides a growth advantage for cancer cells.
Collapse
Affiliation(s)
- Chun-Chi Wu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
13
|
The Mediator complex in thyroid hormone receptor action. Biochim Biophys Acta Gen Subj 2012; 1830:3867-75. [PMID: 22402254 DOI: 10.1016/j.bbagen.2012.02.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/16/2012] [Accepted: 02/21/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Mediator is an evolutionarily conserved multisubunit complex that plays an essential regulatory role in eukaryotic transcription of protein-encoding genes. The human complex was first isolated as a transcriptional coactivator bound to the thyroid hormone receptor (TR) and has since been shown to play a key coregulatory role for a broad range of nuclear hormone receptors (NRs) as well as other signal-activated transcription factors. SCOPE OF REVIEW We provide a general overview of Mediator structure and function, summarize the mechanisms by which Mediator is targeted to NRs, and outline recent evidence revealing Mediator as a regulatory axis for other distinct coregulatory factors, chromatin modifying enzymes and cellular signal transduction pathways. MAJOR CONCLUSIONS Besides serving as a functional interface with the RNA polymerase II basal transcription machinery, Mediator plays a more versatile role in regulating transcription including the ability to: a) facilitate gene-specific chromatin looping events; b) coordinate chromatin modification events with preinitiation complex assembly; and c) regulate critical steps that occur during transcriptional elongation. The variably associated MED1 subunit continues to emerge as a pivotal player in Mediator function, not only as the primary interaction site for NRs, but also as a crucial interaction hub for other coregulatory factors, and as an important regulatory target for signal-activated kinases. GENERAL SIGNIFICANCE Mediator plays an integral coregulatory role at NR target genes by functionally interacting with the basal transcription apparatus and by coordinating the action of chromatin modifying enzymes and transcription elongation factors. This article is part of a Special Issue entitled Thyroid hormone signalling.
Collapse
|
14
|
Nagalingam A, Tighiouart M, Ryden L, Joseph L, Landberg G, Saxena NK, Sharma D. Med1 plays a critical role in the development of tamoxifen resistance. Carcinogenesis 2012; 33:918-30. [PMID: 22345290 DOI: 10.1093/carcin/bgs105] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Understanding the molecular pathways that contribute to the development of tamoxifen resistance is a critical research priority as acquired tamoxifen resistance is the principal cause of poor prognosis and death of patients with originally good prognosis hormone-responsive breast tumors. In this report, we provide evidence that Med1, an important subunit of mediator coactivator complex, is spontaneously upregulated during acquired tamoxifen-resistance development potentiating agonist activities of tamoxifen. Phosphorylated Med1 and estrogen receptor (ER) are abundant in tamoxifen-resistant breast cancer cells due to persistent activation of extracellular signal-regulated kinases. Mechanistically, phosphorylated Med1 exhibits nuclear accumulation, increased interaction with ER and higher tamoxifen-induced recruitment to ER-responsive promoters, which is abrogated by inhibition of Med1 phosphorylation. Stable knockdown of Med1 in tamoxifen-resistant cells not only reverses tamoxifen resistance in vitro but also in vivo. Finally, higher expression levels of Med1 in the tumor significantly correlated with tamoxifen resistance in ER-positive breast cancer patients on adjuvant tamoxifen monotherapy. In silico analysis of breast cancer, utilizing published profiling studies showed that Med1 is overexpressed in aggressive subsets. These findings provide what we believe is the first evidence for a critical role for Med1 in tamoxifen resistance and identify this coactivator protein as an essential effector of the tamoxifen-induced breast cancer growth.
Collapse
Affiliation(s)
- Arumugam Nagalingam
- Department of Oncology and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University School of Medicine, 1650 Orleans Street, CRB 1, Room 145, Baltimore, MD 21231, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
O'Shea LC, Mehta J, Lonergan P, Hensey C, Fair T. Developmental competence in oocytes and cumulus cells: candidate genes and networks. Syst Biol Reprod Med 2012; 58:88-101. [PMID: 22313243 DOI: 10.3109/19396368.2012.656217] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Common aspects of infertility can be seen across several species. In humans, dairy cows, and mares there is only a 25-35% chance of producing a live offspring after a single insemination, whether natural or artificial. Oocyte quality and subsequent embryo development can be affected by factors such as nutrition, hormonal regulation, and environmental influence. The objective of this study was to identify genes expressed in oocytes and/or cumulus cells, across a diverse range of species, which may be linked to the ability an oocyte has to develop following fertilization. Performing a meta-analysis on previously published microarray data on various models of oocyte and embryo quality allowed for the identification of 56 candidate genes associated with oocyte quality across several species, 4 of which were identified in the cumulus cells that surround the oocyte. Twenty-one potential biomarkers were associated with increased competence and 35 potential biomarkers were associated with decreased competence. The upregulation of Metap2, and the decrease of multiple genes linked to mRNA and protein synthesis in models of competence, highlights the importance of de novo protein synthesis and its regulation for successful oocyte maturation and subsequent development. The negative regulation of Wnt signaling has emerged in human, monkey, bovine, and mouse models of oocyte competence. Atrx expression was linked to decreased competence in both oocytes and cumulus cells. Biological networks and transcription factor regulation associated with increased and decreased competence were also identified. These genes could potentially act as biomarkers of oocyte quality or as pharmacological targets for manipulation in order to improve oocyte developmental potential.
Collapse
Affiliation(s)
- Lynne C O'Shea
- School of Biomolecular and Biomedical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | | | | | | | | |
Collapse
|
16
|
Abstract
How is specificity transmitted over long distances at the molecular level? REs (regulatory elements) are often far from transcription start sites. In the present review we discuss possible mechanisms to explain how information from specific REs is conveyed to the basal transcription machinery through TFs (transcription factors) and the Mediator complex. We hypothesize that this occurs through allosteric pathways: binding of a TF to a RE results in changes in the AD (activation domain) of the TF, which binds to Mediator and alters the distribution of the Mediator conformations, thereby affecting transcription initiation/activation. We argue that Mediator is formed by highly disordered proteins with large densely packed interfaces that make efficient long-range signal propagation possible. We suggest two possible general mechanisms for Mediator action: one in which Mediator influences PIC (pre-initiation complex) assembly and transcription initiation, and another in which Mediator exerts its effect on the already assembled but stalled transcription complex. We summarize (i) relevant information from the literature about Mediator composition, organization and structure; (ii) Mediator interaction partners and their effect on Mediator conformation, function and correlation to the RNA Pol II (polymerase II) CTD (C-terminal domain) phosphorylation; and (iii) propose that different allosteric signal propagation pathways in Mediator relate to PIC assembly and polymerase activation of the stalled transcription complex. The emerging picture provides for the first time a mechanistic view of allosteric signalling from the RE sequence to transcription activation, and an insight into how gene specificity and signal transmission can take place in transcription initiation.
Collapse
Affiliation(s)
- Chung-Jung Tsai
- Basic Science Program, SAIC-Frederick, Center for Cancer Research Nanobiology Program NCI-Frederick, Frederick, MD 21702, U.S.A
| | - Ruth Nussinov
- Basic Science Program, SAIC-Frederick, Center for Cancer Research Nanobiology Program NCI-Frederick, Frederick, MD 21702, U.S.A
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
17
|
Ries D, Meisterernst M. Control of gene transcription by Mediator in chromatin. Semin Cell Dev Biol 2011; 22:735-40. [PMID: 21864698 DOI: 10.1016/j.semcdb.2011.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/02/2011] [Accepted: 08/08/2011] [Indexed: 01/07/2023]
Abstract
The Mediator complex serves as an adaptor for regulatory factors, recruits and controls RNA polymerase II promotes preinitiation complex formation and functions post initiation. There is increasing evidence for further coordinating roles of the Mediator complex in chromatin. Here we summarize interactions with regulatory, general and accessory factors that function in transcription and chromatin.
Collapse
Affiliation(s)
- David Ries
- Institute of Molecular Tumor Biology, Westfalian Wilhelms University, Münster, Germany, Robert-Koch Strasse 43, 48149 Münster, Germany
| | | |
Collapse
|
18
|
Interactions between subunits of the Mediator complex with gene-specific transcription factors. Semin Cell Dev Biol 2011; 22:759-68. [PMID: 21839847 DOI: 10.1016/j.semcdb.2011.07.022] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 07/26/2011] [Accepted: 07/28/2011] [Indexed: 11/24/2022]
Abstract
The Mediator complex forms the bridge between gene-specific transcription factors and the RNA polymerase II (RNAP II) machinery. Mediator is a large polypetide complex consisting of about thirty polypeptides that are mostly conserved from yeast to human. Mediator coordinates RNAP II recruitment, phosphorylation of the C-terminal domain of RNAP II, enhancer-loop formation and post-initiation events. The focus of the review is to summarize the current knowledge of transcription factor/Mediator interactions in higher eukaryotes and illuminate the physiological and gene-selective roles of Mediator.
Collapse
|
19
|
Ma B, Tsai CJ, Haliloğlu T, Nussinov R. Dynamic allostery: linkers are not merely flexible. Structure 2011; 19:907-17. [PMID: 21742258 PMCID: PMC6361528 DOI: 10.1016/j.str.2011.06.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/05/2011] [Accepted: 06/07/2011] [Indexed: 12/19/2022]
Abstract
Most proteins consist of multiple domains. How do linkers efficiently transfer information between sites that are on different domains to activate the protein? Mere flexibility only implies that the conformations would be sampled. For fast timescales between triggering events and cellular response, which often involves large conformational change, flexibility on its own may not constitute a good solution. We posit that successive conformational states along major allosteric propagation pathways are pre-encoded in linker sequences where each state is encoded by the previous one. The barriers between these states that are hierarchically populated are lower, achieving faster timescales even for large conformational changes. We further propose that evolution has optimized the linker sequences and lengths for efficiency, which explains why mutations in linkers may affect protein function and review the literature in this light.
Collapse
Affiliation(s)
- Buyong Ma
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, NCI-Frederick, Frederick, MD 21702, USA
| | - Chung-Jung Tsai
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, NCI-Frederick, Frederick, MD 21702, USA
| | - Türkan Haliloğlu
- Polymer Research Center and Chemical Engineering Department, Bogazici University, Bebek-Istanbul 34342, Turkey
| | - Ruth Nussinov
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, NCI-Frederick, Frederick, MD 21702, USA
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
20
|
Tesfaye D, Regassa A, Rings F, Ghanem N, Phatsara C, Tholen E, Herwig R, Un C, Schellander K, Hoelker M. Suppression of the transcription factor MSX1 gene delays bovine preimplantation embryo development in vitro. Reproduction 2010; 139:857-70. [DOI: 10.1530/rep-09-0312] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study was conducted to investigate the effect of suppressing transcription factor geneMSX1on the development ofin vitroproduced bovine oocytes and embryos, and identify its potential target genes regulated by this gene. Injection of long double-stranded RNA (LdsRNA) and small interfering RNA (siRNA) at germinal vesicle stage oocyte reducedMSX1mRNA expression by 73 and 37% respectively at metaphase II stage compared with non-injected controls. Similarly, injection of the same anti-sense oligomers at zygote stage reducedMSX1mRNA expression by 52 and 33% at 8-cell stage compared with non-injected controls. Protein expression was also reduced in LdsRNA- and siRNA-injected groups compared with non-injected controls at both stages. Blastocysts rates were 33, 28, 20 and 18% in non-injected control, scrambled RNA (scRNA), LdsRNA- and siRNA-injected groups respectively. Cleavage rates were also significantly reduced in Smartpool siRNA (SpsiRNA)-injected group (53.76%) compared with scRNA-injected group (57.76%) and non-injected control group (61%). Large-scale gene expression analysis showed that 135 genes were differentially regulated in SpsiRNA-injected group compared with non-injected controls, of which 54 and 81 were down- and up-regulated respectively due to suppression ofMSX1. Additionally, sequence homology mapping and gene enrichment analysis with known human pathway information identified several functional modules that were affected due to suppression ofMSX1. In conclusion, suppression ofMSX1affects oocyte maturation, embryo cleavage rate and the expression of several genes, suggesting its potential role in the development of bovine preimplantation embryos.
Collapse
|
21
|
Karthigeyan D, Prasad SBB, Shandilya J, Agrawal S, Kundu TK. Biology of Aurora A kinase: implications in cancer manifestation and therapy. Med Res Rev 2010; 31:757-93. [PMID: 20196102 DOI: 10.1002/med.20203] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Aurora A kinase belongs to serine/threonine group of kinases, well known for its role in cell cycle, especially in the regulation of mitosis. Numerous substrates of Aurora A kinase have been identified, which are predominantly related to cell cycle progression while some of them are transcription factors. Aurora A-mediated phosphorylation can either directly or indirectly regulate the function of its substrates. There are overwhelming evidences which report overexpression and gene amplification of Aurora A in several human cancers, and suggest that Aurora A could be a bona fide oncogene involved in tumorigenesis. Hence, Aurora A plays wide-ranging roles in both mitosis and its deregulation manifests in cancer progression. These observations have favored the choice of Aurora kinases as a target for cancer therapy. Recently, numerous small molecules have been discovered against Aurora kinases and many have entered clinical trials. Most of these small-molecule modulators designed are specific against either Aurora A or Aurora B, but some are dual inhibitors targeting the ATP-binding site which is highly conserved among the three human homologues of Aurora kinase. In this review, we discuss the physiological functions of Aurora A, interactions between Aurora A kinase and its cellular substrates, tumorigenesis mediated by Aurora A kinase upon overexpression, and small-molecule modulators of Aurora kinase as targets for cancer therapy.
Collapse
Affiliation(s)
- Dhanasekaran Karthigeyan
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | | | | | | | | |
Collapse
|
22
|
Jiang S, Katayama H, Wang J, Li SA, Hong Y, Radvanyi L, Li JJ, Sen S. Estrogen-induced aurora kinase-A (AURKA) gene expression is activated by GATA-3 in estrogen receptor-positive breast cancer cells. Discov Oncol 2010; 1:11-20. [PMID: 21761347 DOI: 10.1007/s12672-010-0006-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 01/05/2010] [Indexed: 01/30/2023] Open
Abstract
Aurora-A is a proto-oncogenic mitotic kinase that is frequently overexpressed in human epithelial malignancies including in breast and ovarian cancers. The mechanism of transcriptional upregulation of Aurora-A in human breast cancer is not yet elucidated. We report herein that Aurora-A transcription is positively regulated by GATA-3 in response to estrogen in estrogen receptor α (ERα)-positive cells. Transient expression of aurora-A promoter deletion mutants in luciferase constructs identified a GATA binding sequence motif as a functional regulatory element in ERα-positive breast cancer cells. Electrophoretic mobility shift assay identified the binding of regulatory proteins to the GATA element. Anti-GATA-3 antibody generated a supershifted complex. Recruitment of GATA-3 to the aurora-A promoter was verified by chromatin immunoprecipitation analysis with GATA-3 antibody. Ectopic expression of GATA-3 resulted in elevated expression of Aurora-A in both ERα-positive and negative cells while siRNA-mediated silencing led to downregulation of endogenous Aurora-A in ERα-positive cells. Estrogen treatment of ERα-positive cells induced increased Aurora-A expression with enhanced recruitment of GATA-3 to the aurora-A promoter. Finally, in the ACI rat model of estrogen-induced breast cancer, known to be associated with elevated Aurora-A expression, we observed increased expression of GATA-3 in preinvasive and invasive mammary epithelial cells exposed to prolonged estrogen treatment and in developing breast tumors. These results demonstrate a direct positive role of estrogen in regulating Aurora-A expression through activation of the ERα-GATA-3 signaling cascade and suggest that this pathway may be critical in the origin of estrogen-stimulated sporadic breast cancer.
Collapse
Affiliation(s)
- Shoulei Jiang
- Department of Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Mouillet JF, Chu T, Nelson DM, Mishima T, Sadovsky Y. MiR-205 silences MED1 in hypoxic primary human trophoblasts. FASEB J 2010; 24:2030-9. [PMID: 20065103 DOI: 10.1096/fj.09-149724] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Acting through degradation of target mRNA or inhibition of translation, microRNAs (miRNAs) regulate development, differentiation, and cellular response to diverse cues. We analyzed changes in miRNA expression in human placental trophoblasts exposed to hypoxia, which may result from hypoperfusion and placental injury. Using an miRNA microarray screen, confirmed by Northern blot analysis, we defined a set of seven miRNAs (miR-93, miR-205, miR-224, miR-335, miR-424, miR-451, and miR-491) that are differentially regulated in primary trophoblasts exposed to hypoxia. We combined in silico prediction of miRNA targets with gene expression profiling data to identify a series of potential targets for the miRNAs, which were further analyzed using luciferase reporter assays. Among experimentally confirmed targets, we found that the transcriptional coactivator MED1, which plays an important role in placental development, is a target for miR-205. Using gain- and loss-of-function assays, we confirmed that miR-205 interacts with a specific target in the 3'-UTR sequence of MED1 and silences MED1 expression in human trophoblasts exposed to hypoxia, suggesting that miR-205 plays a role in trophoblast injury.
Collapse
Affiliation(s)
- Jean-Francois Mouillet
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, Pittsburgh, PA 15213, USA
| | | | | | | | | |
Collapse
|
24
|
Peroxisome-proliferator-activated receptor-binding protein (PBP) is essential for the growth of active Notch4-immortalized mammary epithelial cells by activating SOX10 expression. Biochem J 2009; 425:435-44. [PMID: 19852756 DOI: 10.1042/bj20091237] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PBP (peroxisome-proliferator-activated receptor-binding protein) [Med1 (mediator 1)/TRAP220 (thyroid-hormone-receptor-associated protein 220)] is essential for mammary gland development. We established a mammary epithelial cell line with a genotype of PBPLoxP/LoxP by expressing an active form of Notch4. Null mutation of PBP caused severe growth inhibition of the Notch4-immortalized mammary cells. We found that truncated PBP without the two LXXLL motifs could reverse the growth inhibition due to the deficiency of endogenous PBP, indicating that signalling through nuclear receptors is unlikely to be responsible for the growth inhibition as the result of PBP deficiency. Loss of PBP expression was shown to completely ablate the expression of SOX10 [Sry-related HMG (high-mobility group) box gene 10]. The re-expression of SOX10 was capable of reversing the growth inhibition due to PBP deficiency, whereas suppressed expression of SOX10 inhibited the growth of Notch4-immortalized mammary cells. Further studies revealed PBP is directly recruited to the enhancer of the SOX10 gene, indicating that SOX10 is a direct target gene of PBP. We conclude that PBP is essential for the growth of Notch4-immortalized mammary cells by activating SOX10 expression, providing a potential molecular mechanism through which PBP regulates the growth of mammary stem/progenitor cells.
Collapse
|
25
|
Ndong JDLC, Jean D, Rousselet N, Frade R. Down-regulation of the expression of RB18A/MED1, a cofactor of transcription, triggers strong tumorigenic phenotype of human melanoma cells. Int J Cancer 2009; 124:2597-606. [PMID: 19243021 DOI: 10.1002/ijc.24253] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The RB18A/MED1 human gene, also named TRAP220, DRIP205 and PBP, encodes for a single 205 kDa component, which interacts with nuclear receptors and transcription factors. RB18A/MED1 chromosome localization on locus 17q12-q21.1 suggests its involvement in human cancers. We herein analyzed RB18A/MED1 expression in human melanoma cell lines. We found that RB18A/MED1 is either highly or weakly expressed in melanoma cells, depending on their respectively non or highly-tumorigenic phenotype. We therefore investigated the possible existence of a relationship between the RB18A/MED1 expression level and melanoma cell phenotype. For this purpose, we down-regulated RB18A/MED1 expression by transfecting melanoma cells with a RB18A/MED1 small interfering RNA (siRNA), specific to the 3'-untranslated region of native RB18A/MED1 RNA, already demonstrated to inhibit specifically RB18A/MED1 protein expression. A nonspecific (scrambled) siRNA was used as control. This RB18A/MED1 siRNA did not modify the expression of cathepsin L forms or lamin A/C, nor the secretion of procathepsin L and MMP2 in transfected cells. Analysis using a microarray membrane with 113 cancer-related genes, western blot and specific tests, demonstrated that RB18A/MED1 knockdown significantly inhibits tissue inhibitor of metalloproteinase-3 expression, and increases uPAR expression, two genes well known to be involved in melanoma cell invasion, through modifications of the tumor microenvironment. Indeed, RB18A/MED1 knockdown in melanoma cells in vitro increased their invasive properties, without modification of cell proliferation. Furthermore, RB18A/MED1 knockdown in vivo switched melanoma phenotype from non to strongly-tumorigenic in nude mice. Our data thus demonstrated for the first time that a decrease of RB18A/MED1 expression in human melanoma cells increases their tumorigenic phenotype.
Collapse
Affiliation(s)
- Jean de La Croix Ndong
- INSERM U.672, Immunochemistry of Cell Regulations and Viral Interactions, EVRY Cedex, France
| | | | | | | |
Collapse
|
26
|
|
27
|
Varicella-zoster virus IE62 protein utilizes the human mediator complex in promoter activation. J Virol 2008; 82:12154-63. [PMID: 18842726 DOI: 10.1128/jvi.01693-08] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The varicella-zoster virus (VZV) major transactivator, IE62, is involved in the expression of all kinetic classes of VZV genes and can also activate cellular promoters, promoters from heterologous viruses, and artificial promoters containing only TATA elements. A key component of the mechanism of IE62 transactivation is an acidic activation domain comprising the N-terminal 86 amino acids of IE62. However, the cellular target of this N-terminal acidic activation is unknown. In the work presented here, we show that the IE62 activation domain targets the human Mediator complex via the Med25 (ARC92) subunit and that this interaction appears to be fundamental for transactivation by the IE62 activation domain. In contrast, the Med23 subunit (Sur2/TRAP150beta/DRIP130/CRSP130) of the Mediator complex is not essential for IE62-mediated activation. Further, the IE62 activation domain appears to selectively interact with a form of the Mediator complex lacking CDK8. Chromatin immunoprecipitation experiments showed that IE62 stimulates recruitment of Mediator to an IE62-responsive model promoter. Finally, immunofluorescence microscopy of VZV-infected cells demonstrated intranuclear translocation of the Mediator complex to viral replication compartments. These studies suggest that Mediator is an essential component for efficient VZV gene expression.
Collapse
|
28
|
He L, Yang H, Ma Y, Pledger WJ, Cress WD, Cheng JQ. Identification of Aurora-A as a direct target of E2F3 during G2/M cell cycle progression. J Biol Chem 2008; 283:31012-20. [PMID: 18776222 DOI: 10.1074/jbc.m803547200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Aurora-A is a centrosome kinase and plays a pivotal role in G(2)/M cell cycle progression. Expression of Aurora-A is cell cycle-dependent. Levels of Aurora-A mRNA and protein are low in G(1)/S, accumulate during G(2)/M, and decrease rapidly after mitosis. Previous studies have shown regulation of the Aurora-A protein level during the cell cycle through the ubiquitin-proteasome pathway. However, the mechanism of transcriptional regulation of Aurora-A remains largely unknown. Here, we demonstrated that E2F3 modulates Aurora-A mRNA expression during the cell cycle. Ectopic expression of E2F3 induces Aurora-A expression. Stable knockdown of E2F3 decreases mRNA and protein levels of Aurora-A and delays G(2)/M entry. Further, E2F3 directly binds to Aurora-A promoter and stimulates the promoter activity. Deletion and mutation analyses of the Aurora-A promoter revealed that a region located 96-bp upstream of the transcription initiation site is critical for the activation of the promoter by E2F3. In addition, expression of E2F3 positively correlates with the protein level of Aurora-A in human ovarian cancer examined. These results indicate for the first time that Aurora-A is transcriptionally regulated by E2F3 during the cell cycle and that E2F3 is a causal factor for up-regulation of Aurora-A in a subset of human ovarian cancer. Thus, the E2F3-Aurora-A axis could be an important target for cancer intervention.
Collapse
Affiliation(s)
- Lili He
- Molecular Oncology Department, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 133612, USA
| | | | | | | | | | | |
Collapse
|
29
|
Hung LY, Tseng JT, Lee YC, Xia W, Wang YN, Wu ML, Chuang YH, Lai CH, Chang WC. Nuclear epidermal growth factor receptor (EGFR) interacts with signal transducer and activator of transcription 5 (STAT5) in activating Aurora-A gene expression. Nucleic Acids Res 2008; 36:4337-51. [PMID: 18586824 PMCID: PMC2490761 DOI: 10.1093/nar/gkn417] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Loss of the maintenance of genetic material is a critical step leading to tumorigenesis. It was reported that overexpression of Aurora-A and the constitutive activation of the epidermal growth factor (EGF) receptor (EGFR) are implicated in chromosome instability. In this study, we examined that when cells treated with EGF result in centrosome amplification and microtubule disorder, which are critical for genetic instability. Interestingly, the expression of Aurora-A was also increased by EGF stimulus. An immunofluorescence assay indicated that EGF can induce the nuclear translocation of EGFR. Chromatin immunoprecipitation (ChIP) and re-ChIP assays showed significant EGF-induced recruitment of nuclear EGFR and signal transducer and activator of transcription 5 (STAT5) to the Aurora-A promoter. A co-immunoprecipitation assay further demonstrated that EGF induces nuclear interaction between EGFR and STAT5. A small interfering (si)RNA knockdown assay also showed that EGFR and STAT5 are indeed involved in EGF-increased Aurora-A gene expression. Altogether, this study proposes that the nuclear EGFR associates with STAT5 to bind and increase Aurora-A gene expression, which ultimately may lead to chromosome instability and tumorigenesis. The results also provide a novel linkage between the EGFR signaling pathway and overexpression of Aurora-A in tumorigenesis and chromosome instability.
Collapse
Affiliation(s)
- Liang-Yi Hung
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Klein A, Flügel D, Kietzmann T. Transcriptional regulation of serine/threonine kinase-15 (STK15) expression by hypoxia and HIF-1. Mol Biol Cell 2008; 19:3667-75. [PMID: 18562694 DOI: 10.1091/mbc.e08-01-0042] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The serine/threonine kinase-15 (STK15) acts as a cell cycle regulator being overexpressed in various tumors. One mechanism that could contribute to overexpression of STK15 is tumor hypoxia where hypoxia-inducible factor-1 (HIF-1) is a major regulator of transcription. Therefore, we analyzed whether hypoxia and HIF-1 could contribute to overexpression of STK15. We found that hypoxia increased STK15 expression and STK15 promoter activity in HepG2 tumor cells. Overexpression of HIF-1 alpha induced STK15 gene transcription, whereas HIF-1 alpha siRNA and overexpression of prolyl hydroxylase 2 (PHD-2), a negative regulator of HIF-1 alpha, reversed this effect. In addition, site-directed mutagenesis experiments and chromatin immunoprecipitation revealed that from the three putative hypoxia responsive elements (HRE) within the STK15 promoter only HRE-2 was functional and bound HIF-1. Further, siRNA against STK15 inhibited proliferation of HepG2 cells induced by hypoxia. These results show that STK15 gene transcription can be regulated by hypoxia and HIF-1 via HRE-2 of the STK15 promoter. Thus, tumor hypoxia may trigger overexpression of STK15 observed in various tumors.
Collapse
Affiliation(s)
- Alexandra Klein
- Department of Biochemistry, Faculty of Chemistry, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | | | | |
Collapse
|
31
|
MED1 phosphorylation promotes its association with mediator: implications for nuclear receptor signaling. Mol Cell Biol 2008; 28:3932-42. [PMID: 18391015 DOI: 10.1128/mcb.02191-07] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mediator is a conserved multisubunit complex that acts as a functional interface between regulatory transcription factors and the general RNA polymerase II initiation apparatus. MED1 is a pivotal component of the complex that binds to nuclear receptors and a broad array of other gene-specific activators. Paradoxically, MED1 is found in only a fraction of the total cellular Mediator complexes, and the mechanisms regulating its binding to the core complex remain unclear. Here, we report that phosphorylation of MED1 by mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK-ERK) promotes its association with Mediator. We show that MED1 directly binds to the MED7 subunit and that ERK phosphorylation of MED1 enhances this interaction. Interestingly, we found that both thyroid and steroid hormones stimulate MED1 phosphorylation in vivo and that MED1 phosphorylation is required for its nuclear hormone receptor coactivator activity. Finally, we show that MED1 phosphorylation by ERK enhances thyroid hormone receptor-dependent transcription in vitro. Our findings suggest that ERK phosphorylation of MED1 is a regulatory mechanism that promotes MED1 association with Mediator and, as such, may facilitate a novel feed-forward action of nuclear hormones.
Collapse
|
32
|
Dessie SW, Rings F, Hölker M, Gilles M, Jennen D, Tholen E, Havlicek V, Besenfelder U, Sukhorukov VL, Zimmermann U, Endter JM, Sirard MA, Schellander K, Tesfaye D. Dielectrophoretic behavior of in vitro-derived bovine metaphase II oocytes and zygotes and its relation to in vitro embryonic developmental competence and mRNA expression pattern. Reproduction 2007; 133:931-46. [PMID: 17616723 DOI: 10.1530/rep-06-0277] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Selecting developmentally competent oocytes and zygotes based on their morphology is more often influenced by personal judgments and lacks universal standards. Therefore, this experiment was conducted to investigate the rate of development and mRNA level of dielectrophoretically separated oocytes and zygotes to validate dielectrophoresis (DEP) as non-invasive option for selection of oocytes and zygotes. In the first experiment, metaphase II oocytes with (PB(+)) and without (PB(-)) first polar body and zygotes were subjected to DEP at 4 MHz and 450 mum electrode distance and classified into fast, very fast, slow, and very slow depending on the time elapsed to reach one of the electrodes in the electric field. Parthenogenetic activation was employed to monitor the embryonic development of dielectrophoretically classified oocytes. The result revealed that at 6 and 7 days of post-activation, the blastocyst rate of very slow dielectrophoretic PB(+) and PB(-) oocytes was significantly (P < 0.05) lower than other groups. Similarly, in zygotes, the blastocyst rate at 7 days post-insemination was higher (P < 0.05) in the very fast dielectrophoretic categories when compared with the slow and very slow categories. In the second experiment, mRNA level was analyzed in the very fast and very slow dielectrophoretic PB(+) oocytes and zygotes respectively using the bovine cDNA microarray. The result showed that 36 and 42 transcripts were differentially regulated between the very fast and very slow dielectrophoretic categories PB(+) oocytes and zygotes respectively. In conclusion, dielectrophoretically separated oocytes and zygotes showed difference in the rate of blastocyst development accompanied by difference in transcriptional abundances.
Collapse
Affiliation(s)
- Salilew-Wondim Dessie
- Animal Breeding and Husbandry Group, Institute of Animal Science, University of Bonn, Endenicher Allee 15, Bonn, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Vijayvargia R, May MS, Fondell JD. A coregulatory role for the mediator complex in prostate cancer cell proliferation and gene expression. Cancer Res 2007; 67:4034-41. [PMID: 17483314 DOI: 10.1158/0008-5472.can-06-3039] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Androgen receptor (AR) signaling pathways are important for the survival and proliferation of prostate cancer cells. Because AR activity is facilitated by distinct coregulatory factors and complexes, it is conceivable that some of these proteins might also play a role in promoting prostate oncogenesis. The multisubunit Mediator complex is an important coactivator for a broad range of regulatory transcriptional factors including AR, yet its role in prostate cancer is unclear. Here, we used RNA interference to knock down the expression of two integral Mediator components, MED1/TRAP220 and MED17, in prostate cancer cells. MED1/TRAP220 plays a particularly important role in androgen signaling in that it serves as a direct binding target for AR. We found that the knockdown of either subunit markedly decreases transcription from transiently transfected androgen-responsive reporter genes, as well as inhibits androgen-dependent expression of endogenous AR target genes. We show for the first time that loss of either MED1/TRAP220 or MED17 in prostate cancer cells significantly decreases both androgen-dependent and -independent cellular proliferation, inhibits cell cycle progression, and increases apoptosis. Furthermore, we show that MED1/TRAP220 is overexpressed in both AR-positive and -negative prostate cancer cells lines, as well as in 50% (10 of 20) of the clinically localized human prostate cancers we examined, thus suggesting that MED1/TRAP220 hyperactivity may have implications in prostate oncogenesis. In sum, our data suggest that Mediator plays an important coregulatory role in prostate cancer cell proliferation and survival, and therefore, may represent a new target for therapeutic intervention.
Collapse
Affiliation(s)
- Ravi Vijayvargia
- Department of Physiology and Biophysics, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854, USA
| | | | | |
Collapse
|
34
|
Nuclear receptor transcriptional coactivators in development and metabolism. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1574-3349(06)16012-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|