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Elevated TAF12 Expression Predicts Poor Prognosis in Glioma Patients: Evidence from Bioinformatic and Immunohistochemical Analyses. Biomolecules 2022; 12:biom12121847. [PMID: 36551275 PMCID: PMC9775265 DOI: 10.3390/biom12121847] [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: 10/28/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
TATA box-binding protein-associated factor 12 (TAF12) has been identified as an oncogene in choroid plexus carcinoma, but its role in glioma is poorly understood because of a lack of previous studies. This study investigated the relationship of TAF12 expression with the clinicopathologic features of glioma cases, as well as its prognostic value and biological function, using large-scale databases and clinical samples. TAF12 mRNA expression and clinicopathologic characteristics of glioma cases were assessed in three public databases, and bioinformatics analyses were conducted to explore the prognostic value and biological functions of TAF12 in glioma. High TAF12 expression was commonly associated with reduced survival time and poor clinical indexes, including higher World Health Organization grade, wild-type isocitrate dehydrogenase 1 expression, and 1p19q non-codeletion status (p < 0.0001). Multivariate Cox regression analysis showed that high TAF12 expression was an independent poor prognostic factor for glioma patients (hazard ratio = 1.41, 95% confidence interval, 1.18-1.68, p < 0.001). Functional enrichment analysis revealed involvement of TAF12 in immune and inflammatory responses in glioma. Also, expression of several immune checkpoint molecules was significantly higher in samples with high TAF12 expression. TAF12 is a potential independent prognostic factor for glioma, and these findings provide a foundation for further investigation of the potential role of TAF12 in immunotherapy.
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Offermann A, Kang D, Watermann C, Weingart A, Hupe MC, Saraji A, Stegmann-Frehse J, Kruper R, Schüle R, Pantel K, Taubert H, Duensing S, Culig Z, Aigner A, Klapper W, Jonigk D, Philipp Kühnel M, Merseburger AS, Kirfel J, Sailer V, Perner S. Manuscript Title: Analysis of tripartite motif (TRIM) family gene expression in prostate cancer bone metastases. Carcinogenesis 2021; 42:1475-1484. [PMID: 34487169 DOI: 10.1093/carcin/bgab083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/29/2021] [Accepted: 09/04/2021] [Indexed: 12/27/2022] Open
Abstract
Tripartite motif (TRIM) family proteins are post-translational protein modifiers with E3-ubiquitin ligase activity, thereby involved in various biological processes. The molecular mechanisms driving prostate cancer (PCa) bone metastasis (BM) are incompletely understood, and targetable genetic alterations are lacking in the majority of cases. Therefore, we aimed to explore the expression and potential functional relevance of 71 TRIM members in bone metastatic PCa. We performed transcriptome analysis of all human TRIM family members and 770 cancer-related genes in 29 localized PCa and 30 PCa BM using Nanostring. KEGG, STRING and Ubibrowser were used for further bioinformatic gene correlation and pathway enrichment analyses. Compared to localized tumors, six TRIMs are under-expressed while nine TRIMs are over-expressed in BM. The differentially expressed TRIM proteins are linked to TNF-, TGFβ-, PI3K/AKT- and HIF-1-signaling, and to features such as proteoglycans, platelet activation, adhesion and ECM-interaction based on correlation to cancer-related genes. The identification of TRIM-specific E3-ligase-substrates revealed insight into functional connections to oncogenes, tumor suppressors and cancer-related pathways including androgen receptor- and TGFβ signaling, cell cycle regulation and splicing. In summary, this is the first study that comprehensively and systematically characterizes the expression of all TRIM members in PCa BM. Our results describe post-translational protein modification as an important regulatory mechanism of oncogenes, tumor suppressors, and pathway molecules in PCa progression. Therefore, this study may provide evidence for novel therapeutic targets, in particular for the treatment or prevention of BM.
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Affiliation(s)
- Anne Offermann
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Duan Kang
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Christian Watermann
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Anika Weingart
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Marie C Hupe
- Department of Urology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Alireza Saraji
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Janine Stegmann-Frehse
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | | | - Roland Schüle
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Klaus Pantel
- Institute for Tumor Biology, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Helge Taubert
- Department of Urology and Paediatric Urology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Duensing
- Molecular Urooncology, Department of Urology, University Hospital Heidelberg, Heidelberg, Germany
| | - Zoran Culig
- Experimental Urology, Department of Urology, Medical University of Innsbruck, Innsbruck, Austria
| | - Achim Aigner
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, Clinical Pharmacology, Faculty of Medicine, University of Leipzig, Germany
| | - Wolfram Klapper
- Institute of Pathology, Hematopathology Section and Lymph Node Registry, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Danny Jonigk
- Institute of Pathology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Mark Philipp Kühnel
- Institute of Pathology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Axel S Merseburger
- Department of Urology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Jutta Kirfel
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Verena Sailer
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
| | - Sven Perner
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany.,Research Center Borstel, Leibniz Lung Center, Borstel, Germany
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Tong Y, Merino D, Nimmervoll B, Gupta K, Wang YD, Finkelstein D, Dalton J, Ellison DW, Ma X, Zhang J, Malkin D, Gilbertson RJ. Cross-Species Genomics Identifies TAF12, NFYC, and RAD54L as Choroid Plexus Carcinoma Oncogenes. Cancer Cell 2015; 27:712-27. [PMID: 25965574 PMCID: PMC4458854 DOI: 10.1016/j.ccell.2015.04.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/16/2014] [Accepted: 04/10/2015] [Indexed: 01/04/2023]
Abstract
Choroid plexus carcinomas (CPCs) are poorly understood and frequently lethal brain tumors with few treatment options. Using a mouse model of the disease and a large cohort of human CPCs, we performed a cross-species, genome-wide search for oncogenes within syntenic regions of chromosome gain. TAF12, NFYC, and RAD54L co-located on human chromosome 1p32-35.3 and mouse chromosome 4qD1-D3 were identified as oncogenes that are gained in tumors in both species and required for disease initiation and progression. TAF12 and NFYC are transcription factors that regulate the epigenome, whereas RAD54L plays a central role in DNA repair. Our data identify a group of concurrently gained oncogenes that cooperate in the formation of CPC and reveal potential avenues for therapy.
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Affiliation(s)
- Yiai Tong
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Diana Merino
- Genetics and Genome Biology Program, The Hospital for Sick Children, Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Birgit Nimmervoll
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Kirti Gupta
- Department of Pathology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Yong-Dong Wang
- Department of Computational Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - James Dalton
- Department of Pathology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - David W Ellison
- Department of Pathology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Xiaotu Ma
- Department of Computational Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Jinghui Zhang
- Department of Computational Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - David Malkin
- Genetics and Genome Biology Program, The Hospital for Sick Children, Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada; Division of Hematology/Oncology, The Hospital for Sick Children, Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Richard J Gilbertson
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Oncology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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Ribeiro JR, Lovasco LA, Vanderhyden BC, Freiman RN. Targeting TBP-Associated Factors in Ovarian Cancer. Front Oncol 2014; 4:45. [PMID: 24653979 PMCID: PMC3949196 DOI: 10.3389/fonc.2014.00045] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 02/25/2014] [Indexed: 12/11/2022] Open
Abstract
As ovarian tumors progress, they undergo a process of dedifferentiation, allowing adaptive changes in growth and morphology that promote metastasis and chemoresistance. Herein, we outline a hypothesis that TATA-box binding protein associated factors (TAFs), which compose the RNA Polymerase II initiation factor, TFIID, contribute to regulation of dedifferentiation states in ovarian cancer. Numerous studies demonstrate that TAFs regulate differentiation and proliferation states; their expression is typically high in pluripotent cells and reduced upon differentiation. Strikingly, TAF2 exhibits copy number increases or mRNA overexpression in 73% of high-grade serous ovarian cancers (HGSC). At the biochemical level, TAF2 directs TFIID to TATA-less promoters by contact with an Initiator element, which may lead to the deregulation of the transcriptional output of these tumor cells. TAF4, which is altered in 66% of HGSC, is crucial for the stability of the TFIID complex and helps drive dedifferentiation of mouse embryonic fibroblasts to induced pluripotent stem cells. Its ovary-enriched paralog, TAF4B, is altered in 26% of HGSC. Here, we show that TAF4B mRNA correlates with Cyclin D2 mRNA expression in human granulosa cell tumors. TAF4B may also contribute to regulation of tumor microenvironment due to its estrogen-responsiveness and ability to act as a cofactor for NFκB. Conversely, TAF9, a cofactor for p53 in regulating apoptosis, may act as a tumor suppressor in ovarian cancer, since it is downregulated or deleted in 98% of HGSC. We conclude that a greater understanding of mechanisms of transcriptional regulation that execute signals from oncogenic signaling cascades is needed in order to expand our understanding of the etiology and progression of ovarian cancer, and most importantly to identify novel targets for therapeutic intervention.
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Affiliation(s)
| | - Lindsay A Lovasco
- Molecular and Cellular Biology and Biochemistry, Brown University , Providence, RI , USA
| | - Barbara C Vanderhyden
- Cellular and Molecular Medicine, University of Ottawa , Ottawa, ON , Canada ; Centre for Cancer Therapeutics, Ottawa Hospital Research Institute , Ottawa, ON , Canada
| | - Richard N Freiman
- Pathobiology Graduate Program, Brown University , Providence, RI , USA ; Molecular and Cellular Biology and Biochemistry, Brown University , Providence, RI , USA
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Zhao M, Sun J, Zhao Z. Synergetic regulatory networks mediated by oncogene-driven microRNAs and transcription factors in serous ovarian cancer. MOLECULAR BIOSYSTEMS 2013; 9:3187-98. [PMID: 24129674 PMCID: PMC3855196 DOI: 10.1039/c3mb70172g] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although high-grade serous ovarian cancer (OVC) is the most lethal gynecologic malignancy in women, little is known about the regulatory mechanisms in the cellular processes that lead to this cancer. Recently, accumulated lines of evidence have shown that the interplay between transcription factors (TFs) and microRNAs (miRNAs) is critical in cellular regulation during tumorigenesis. A comprehensive investigation of TFs and miRNAs, and their target genes, may provide a deeper understanding of the regulatory mechanisms in the pathology of OVC. In this study, we have integrated three complementary algorithms into a framework, aiming to infer the regulation by miRNAs and TFs in conjunction with gene expression profiles. We demonstrated the utility of our framework by inferring 67 OVC-specific regulatory feed-forward loops (FFL) initiated by miRNAs or TFs in high-grade serous OVC. By analyzing these regulatory behaviors, we found that all the 67 FFLs are consistent in their regulatory effects on genes that are jointly targeted by miRNAs and TFs. Remarkably, we unveiled an unbalanced distribution of FFLs with different oncogenic effects. In total, 31 of the 67 coherent FFLs were mainly initiated by oncogenes. On the contrary, only 4 of the FFLs were initiated by tumor suppressor genes. These overwhelmingly observed oncogenic genes were further detected in a sub-network with 32 FFLs centered by miRNA let-7b and TF TCF7L1 to regulate cell differentiation. Closer inspection of 32 FFLs revealed that 75% of the miRNAs reportedly play functional roles in cell differentiation, especially when enriched in epithelial-mesenchymal transitions. This study provides a comprehensive pathophysiological overview of recurring coherent circuits in OVC that are co-regulated by miRNAs and TFs. The prevalence of oncogenic coherent FFLs in serous OVC suggests that oncogene-driven regulatory motifs could cooperatively act upon critical cellular processes such as cell differentiation in a highly efficient and consistent manner.
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Affiliation(s)
- Min Zhao
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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Teramachi J, Hiruma Y, Ishizuka S, Ishizuka H, Brown JP, Michou L, Cao H, Galson DL, Subler MA, Zhou H, Dempster DW, Windle JJ, Roodman GD, Kurihara N. Role of ATF7-TAF12 interactions in the vitamin D response hypersensitivity of osteoclast precursors in Paget's disease. J Bone Miner Res 2013; 28:1489-500. [PMID: 23426901 PMCID: PMC3663902 DOI: 10.1002/jbmr.1884] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 01/07/2013] [Accepted: 01/21/2013] [Indexed: 11/06/2022]
Abstract
Osteoclast (OCL) precursors from many Paget's disease (PD) patients express measles virus nucleocapsid protein (MVNP) and are hypersensitive to 1,25-dihydroxyvitamin D₂ (1,25-(OH)₂D₃; also know as calcitriol). The increased 1,25-(OH)₂D₃ sensitivity is mediated by transcription initiation factor TFIID subunit 12 (TAF12), a coactivator of the vitamin D receptor (VDR), which is present at much higher levels in MVNP-expressing OCL precursors than normals. These results suggest that TAF12 plays an important role in the abnormal OCL activity in PD. However, the molecular mechanisms underlying both 1,25-(OH)₂D₃'s effects on OCL formation and the contribution of TAF12 to these effects in both normals and PD patients are unclear. Inhibition of TAF12 with a specific TAF12 antisense construct decreased OCL formation and OCL precursors' sensitivity to 1,25-(OH)₂D₃ in PD patient bone marrow samples. Further, OCL precursors from transgenic mice in which TAF12 expression was targeted to the OCL lineage (tartrate-resistant acid phosphatase [TRAP]-TAF12 mice), formed OCLs at very low levels of 1,25-(OH)₂D₃, although the OCLs failed to exhibit other hallmarks of PD OCLs, including receptor activator of NF-κB ligand (RANKL) hypersensitivity and hypermultinucleation. Chromatin immunoprecipitation (ChIP) analysis of OCL precursors using an anti-TAF12 antibody demonstrated that TAF12 binds the 24-hydroxylase (CYP24A1) promoter, which contains two functional vitamin D response elements (VDREs), in the presence of 1,25-(OH)₂D₃. Because TAF12 directly interacts with the cyclic adenosine monophosphate-dependent activating transcription factor 7 (ATF7) and potentiates ATF7-induced transcriptional activation of ATF7-driven genes in other cell types, we determined whether TAF12 is a functional partner of ATF7 in OCL precursors. Immunoprecipitation of lysates from either wild-type (WT) or MVNP-expressing OCL with an anti-TAF12 antibody, followed by blotting with an anti-ATF7 antibody, or vice versa, showed that TAF12 and ATF7 physically interact in OCLs. Knockdown of ATF7 in MVNP-expressing cells decreased cytochrome P450, family 24, subfamily A, polypeptide 1 (CYP24A1) induction by1,25-(OH)₂D₃, as well as TAF12 binding to the CYP24A1 promoter. These results show that ATF7 interacts with TAF12 and contributes to the hypersensitivity of OCL precursors to 1,25-(OH)₂D₃ in PD.
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Affiliation(s)
- Jumpei Teramachi
- Department of Medicine, Hematology Oncology, Indiana University, Indianapolis, IN, USA
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EZH2 is regulated by ERK/AKT and targets integrin alpha2 gene to control Epithelial–Mesenchymal Transition and anoikis in colon cancer cells. Int J Biochem Cell Biol 2013; 45:243-54. [PMID: 23116973 DOI: 10.1016/j.biocel.2012.10.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 10/16/2012] [Accepted: 10/20/2012] [Indexed: 12/21/2022]
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Alvarez A, Woolf PJ. RegNetB: predicting relevant regulator-gene relationships in localized prostate tumor samples. BMC Bioinformatics 2011; 12:243. [PMID: 21682879 PMCID: PMC3128037 DOI: 10.1186/1471-2105-12-243] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 06/17/2011] [Indexed: 11/10/2022] Open
Abstract
Background A central question in cancer biology is what changes cause a healthy cell to form a tumor. Gene expression data could provide insight into this question, but it is difficult to distinguish between a gene that causes a change in gene expression from a gene that is affected by this change. Furthermore, the proteins that regulate gene expression are often themselves not regulated at the transcriptional level. Here we propose a Bayesian modeling framework we term RegNetB that uses mechanistic information about the gene regulatory network to distinguish between factors that cause a change in expression and genes that are affected by the change. We test this framework using human gene expression data describing localized prostate cancer progression. Results The top regulatory relationships identified by RegNetB include the regulation of RLN1, RLN2, by PAX4, the regulation of ACPP (PAP) by JUN, BACH1 and BACH2, and the co-regulation of PGC and GDF15 by MAZ and TAF8. These target genes are known to participate in tumor progression, but the suggested regulatory roles of PAX4, BACH1, BACH2, MAZ and TAF8 in the process is new. Conclusion Integrating gene expression data and regulatory topologies can aid in identifying potentially causal mechanisms for observed changes in gene expression.
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Affiliation(s)
- Angel Alvarez
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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Kalogeropoulou M, Voulgari A, Kostourou V, Sandaltzopoulos R, Dikstein R, Davidson I, Tora L, Pintzas A. TAF4b and Jun/activating protein-1 collaborate to regulate the expression of integrin alpha6 and cancer cell migration properties. Mol Cancer Res 2010; 8:554-68. [PMID: 20353996 DOI: 10.1158/1541-7786.mcr-09-0159] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The TAF4b subunit of the transcription factor IID, which has a central role in transcription by polymerase II, is involved in promoter recognition by selective recruitment of activators. The activating protein-1 (AP-1) family members participate in oncogenic transformation via gene regulation. Utilizing immunoprecipitation of endogenous protein complexes, we documented specific interactions between Jun family members and TATA box binding protein-associated factors (TAF) in colon HT29 adenocarcinoma cells. Particularly, TAF4b and c-Jun were found to colocalize and interact in the nucleus of advanced carcinoma cells and in cells with epithelial-to-mesenchymal transition (EMT) characteristics. TAF4b was found to specifically regulate the AP-1 target gene involved in EMT integrin alpha6, thus altering related cellular properties such as migration potential. Using a chromatin immunoprecipitation approach in colon adenocarcinoma cell lines, we further identified a synergistic role for TAF4b and c-Jun and other AP-1 family members on the promoter of integrin alpha6, underlining the existence of a specific mechanism related to gene expression control. We show evidence for the first time of an interdependence of TAF4b and AP-1 family members in cell type-specific promoter recognition and initiation of transcription in the context of cancer progression and EMT.
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Affiliation(s)
- Margarita Kalogeropoulou
- Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece
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Epithelial–mesenchymal transition in cancer metastasis: Mechanisms, markers and strategies to overcome drug resistance in the clinic. Biochim Biophys Acta Rev Cancer 2009; 1796:75-90. [DOI: 10.1016/j.bbcan.2009.03.002] [Citation(s) in RCA: 350] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 03/05/2009] [Accepted: 03/07/2009] [Indexed: 12/26/2022]
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Papai G, Tripathi MK, Ruhlmann C, Werten S, Crucifix C, Weil PA, Schultz P. Mapping the initiator binding Taf2 subunit in the structure of hydrated yeast TFIID. Structure 2009; 17:363-73. [PMID: 19278651 DOI: 10.1016/j.str.2009.01.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 11/19/2008] [Accepted: 01/05/2009] [Indexed: 11/28/2022]
Abstract
The general transcription factor TFIID is a large multisubunit complex required for the transcription of most protein-encoding genes by RNA polymerase II. Taking advantage of a TFIID preparation partially depleted in the initiator-binding Taf2p subunit, we determined the conformational and biochemical variations of the complex by electron tomography and cryo-electron microscopy of single molecules. Image analysis revealed the extent of conformational flexibility of the complex and the selection of the most homogeneous TFIID subpopulation allowed us to determine an improved structural model at 23 Angstroms resolution. This study also identified two subpopulations of Taf2p-containing and Taf2p-depleted TFIID molecules. By comparing these two TFIID species we could infer the position of Taf2p, which was confirmed by immunolabeling using a subunit-specific antibody. Mapping the position of this crucial subunit in the vicinity of Taf1p and of TBP sheds new light on its role in promoter recognition.
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Affiliation(s)
- Gabor Papai
- Department of Structural Biology and Genomics, Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS/INSERM/ULP, 67404 Illkirch, France
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