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Melotti S, Ambrosi F, Franceschini T, Giunchi F, Filippo GD, Franchini E, Massari F, Mollica V, Tateo V, Bianchi FM, Colecchia M, Acosta AM, Lobo J, Fiorentino M, Ricci C. TAMs PD-L1(+) in the reprogramming of germ cell tumors of the testis. Pathol Res Pract 2023; 247:154540. [PMID: 37209574 DOI: 10.1016/j.prp.2023.154540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/10/2023] [Accepted: 05/16/2023] [Indexed: 05/22/2023]
Abstract
BACKGROUND In recent years, several studies focused on the process of reprogramming of seminoma (S) cells, which regulates the transition from pure S (P-S) to S component (S-C) of mixed germ cell tumors of the testis (GCTT) and finally to embryonal carcinoma (EC) and other nonseminomatous GCTT (NS-GCTT). The accepted pathogenetic model is driven and regulated by cells (macrophages, B- and T-lymphocytes) and molecules of the tumor microenvironment (TME). Herein, we tested a series of GCTT with double staining (DS) for CD68-PD-L1 to evaluate tumor-associated macrophages (TAMs) expressing programmed death-ligand 1 (PD-L1) [TAMs PD-L1(+)] and clarify if these cells may be involved in establishing the fate of GCTT. METHODS We collected 45 GCTT (comprising a total of 62 different components of GCTT). TAMs PD-L1(+) were evaluated with three different scoring systems [TAMs PD-L1(+)/mm2, TAMs PD-L1(+)/mm2H-score, TAMs PD-L1(+) %], and compared using pertinent statistic tests (Student's t-test and Mann-Whitney U test). RESULTS We found that TAMs PD-L1(+) values were higher in S rather than EC (p = 0.001, p = 0.015, p = 0.022) and NS-GCTT (p < 0.001). P-S showed statistically significant differences in TAMs PD-L1(+) values compared to S-C (p < 0.001, p = 0.006, p = 0.015), but there were no differences between S-C and EC (p = 0.107, p = 0.408, p = 0.800). Finally, we found statistically significant differences also in TAMs PD-L1(+) values between EC and other NS-GCTT (p < 0.001). CONCLUSIONS TAMs PD-L1(+) levels gradually decrease during the reprogramming of S cells {P-S [(high values of TAMs PD-L1(+)] → S-C and EC [(intermediate values of TAMs PD-L1(+)] → other NS-GCTT [(low values of TAMs PD-L1(+)], supporting a complex pathogenetic model where the interactions between tumor cells and TME components [and specifically TAMs PD-L1(+)] play a key role in determining the fate of GCTT.
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Affiliation(s)
- Sofia Melotti
- Pathology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Francesca Ambrosi
- Pathology Unit, Maggiore Hospital-AUSL Bologna, Bologna, Italy; Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
| | | | - Francesca Giunchi
- Pathology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | | | | | - Francesco Massari
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy; Medical Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Veronica Mollica
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy; Medical Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Valentina Tateo
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy; Medical Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | | | - Maurizio Colecchia
- Department of Pathology, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Andres Martin Acosta
- Department of Pathology, Indiana University School of Medicine, Indianapolis, USA
| | - João Lobo
- Department of Pathology, Portuguese Oncology Institute of Porto (IPOP), Porto, Portugal; Cancer Biology and Epigenetics Group, Research Center of IPO Porto (GEBC CI-IPOP)/RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center (P.CCC), Porto, Portugal; Department of Pathology and Molecular Immunology, ICBAS-School of Medicine and Biomedical Sciences, University of Porto (ICBAS-UP), Porto, Portugal
| | - Michelangelo Fiorentino
- Pathology Unit, Maggiore Hospital-AUSL Bologna, Bologna, Italy; Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
| | - Costantino Ricci
- Pathology Unit, Maggiore Hospital-AUSL Bologna, Bologna, Italy; Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
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SOX2 and PRAME in the “reprogramming” of seminoma cells. Pathol Res Pract 2022; 237:154044. [DOI: 10.1016/j.prp.2022.154044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/22/2022] [Accepted: 07/26/2022] [Indexed: 11/18/2022]
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Morii A, Katayama S, Inazu T. Establishment of a Simple Method for Inducing Neuronal Differentiation of P19 EC Cells without Embryoid Body Formation and Analysis of the Role of Histone Deacetylase 8 Activity in This Differentiation. Biol Pharm Bull 2020; 43:1096-1103. [PMID: 32612072 DOI: 10.1248/bpb.b20-00091] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
P19 pluripotent embryonic carcinoma (EC) stem cells are derived from pluripotent germ cell tumours and can differentiate into three germ layers. Treatment of these cells in suspension culture with retinoic acid induces their differentiation into neurons and glial cells. Hence, these cells are an excellent in vitro model to study the transition from the upper blastoderm to the neuroectoderm. However, because of the complex nature of the techniques involved, the results are highly dependent on the skills of the experimenter. Herein, we developed a simple method to induce neuronal differentiation of adherent P19 EC cells in TaKaRa NDiff® 227 serum-free medium (originally N2B27 medium). This medium markedly induced neuronal differentiation of P19 EC cells. The addition of retinoic acid to the NDiff® 227 medium further enhanced differentiation. Furthermore, cells differentiated by the conventional method, as well as the new method, showed identical expression of the mature neuronal marker, neuronal nuclei. To determine whether our approach could be applied for neuronal studies, we measured histone deacetylase 8 (HDAC8) activity using an HDAC8 inhibitor and HDAC8-knockout P19 EC cells. Inhibition of HDAC8 activity suppressed neuronal maturation. Additionally, HDAC8-knockout cell lines showed immature differentiation compared to the wild-type cell line. These results indicate that HDAC8 directly regulates the neuronal differentiation of P19 EC cells. Thus, our method involving P19 EC cells can be used as an experimental system to study the nervous system. Moreover, this method is suitable for screening drugs that affect the nervous system and cell differentiation.
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Affiliation(s)
- Atsushi Morii
- Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University
| | - Syouichi Katayama
- Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University
| | - Tetsuya Inazu
- Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University
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Kelly GM, Gatie MI. Mechanisms Regulating Stemness and Differentiation in Embryonal Carcinoma Cells. Stem Cells Int 2017; 2017:3684178. [PMID: 28373885 PMCID: PMC5360977 DOI: 10.1155/2017/3684178] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/10/2017] [Accepted: 02/08/2017] [Indexed: 02/06/2023] Open
Abstract
Just over ten years have passed since the seminal Takahashi-Yamanaka paper, and while most attention nowadays is on induced, embryonic, and cancer stem cells, much of the pioneering work arose from studies with embryonal carcinoma cells (ECCs) derived from teratocarcinomas. This original work was broad in scope, but eventually led the way for us to focus on the components involved in the gene regulation of stemness and differentiation. As the name implies, ECCs are malignant in nature, yet maintain the ability to differentiate into the 3 germ layers and extraembryonic tissues, as well as behave normally when reintroduced into a healthy blastocyst. Retinoic acid signaling has been thoroughly interrogated in ECCs, especially in the F9 and P19 murine cell models, and while we have touched on this aspect, this review purposely highlights how some key transcription factors regulate pluripotency and cell stemness prior to this signaling. Another major focus is on the epigenetic regulation of ECCs and stem cells, and, towards that end, this review closes on what we see as a new frontier in combating aging and human disease, namely, how cellular metabolism shapes the epigenetic landscape and hence the pluripotency of all stem cells.
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Affiliation(s)
- Gregory M. Kelly
- Department of Biology, Molecular Genetics Unit, Western University, London, ON, Canada
- Collaborative Program in Developmental Biology, Western University, London, ON, Canada
- Department of Paediatrics and Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Child Health Research Institute, London, ON, Canada
- Ontario Institute for Regenerative Medicine, Toronto, ON, Canada
- The Hospital for Sick Children, Toronto, ON, Canada
| | - Mohamed I. Gatie
- Department of Biology, Molecular Genetics Unit, Western University, London, ON, Canada
- Collaborative Program in Developmental Biology, Western University, London, ON, Canada
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Bagriacik EU, Yaman M, Haznedar R, Sucak G, Delibasi T. TSH-induced gene expression involves regulation of self-renewal and differentiation-related genes in human bone marrow-derived mesenchymal stem cells. J Endocrinol 2012; 212:169-78. [PMID: 22128326 DOI: 10.1530/joe-11-0404] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bone marrow-derived mesenchymal stem cells are pluripotent cells that are capable of differentiating into a variety of cell types including neuronal cells, osteoblasts, chondrocytes, myocytes, and adipocytes. Despite recent advances in stem cell biology, neuroendocrine relations, particularly TSH interactions remain elusive. In this study, we investigated expression and biological consequence of TSH receptor (TSHR) interactions in mesenchymal stem cells of cultured human bone marrow. To the best of our knowledge, we demonstrated for the first time that human bone marrow-derived mesenchymal stem cells expressed a functional thyrotropin receptor that was capable of transducing signals through cAMP. We extended this study to explore possible pathways that could be associated directly or indirectly with the TSHR function in mesenchymal stem cells. Expression of 80 genes was studied by real-time PCR array profiles. Our investigation indicated involvements of interactions between TSH and its receptor in novel regulatory pathways, which could be the important mediators of self-renewal, maintenance, development, and differentiation in bone marrow-derived mesenchymal stem cells. TSH enhanced differentiation to the chondrogenic cell lineage; however, further work is required to determine whether osteoblastic differentiation is also promoted. Our results presented in this study have opened an era of regulatory events associated with novel neuroendocrine interactions of hypothalamic-pituitary axis in mesenchymal stem cell biology and differentiation.
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Hu SN, Yu H, Zhang YB, Wu ZL, Yan YC, Li YX, Li YY, Li YP. Splice blocking of zygotic sox31 leads to developmental arrest shortly after Mid-Blastula Transition and induces apoptosis in zebrafish. FEBS Lett 2011; 586:222-8. [PMID: 22209980 DOI: 10.1016/j.febslet.2011.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 11/29/2011] [Accepted: 12/06/2011] [Indexed: 10/14/2022]
Abstract
Here we report that splice blocking morpholinos (Sb MO) against zebrafish sox31 elicit developmental arrest, likely through creating a series of dominant negative splicing variants. Embryos injected with the Sb MO develop normally before the Mid-Blastula Transition (MBT); however, they do not initiate epiboly. Microarray analysis of mRNAs collected at the dome stage revealed that the Sb MO impairs activation of a large set of zygotic genes and reduces degradation of maternal mRNA during MBT. Furthermore, an apoptotic response occurs in Sb morphants at about 6hpf. SoxB1 family genes including sox31 thus play an essential role for early embryos traversing the transitional stage.
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Affiliation(s)
- Sheng-Nan Hu
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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7
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Hu S, Wu Z, Yan Y, Li Y. Sox31 is involved in central nervous system anteroposterior regionalization through regulating the organizer activity in zebrafish. Acta Biochim Biophys Sin (Shanghai) 2011; 43:387-99. [PMID: 21467072 DOI: 10.1093/abbs/gmr025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Sox superfamily proteins are DNA-binding transcriptional factors that contain highly conserved high-mobility group (HMG) box and take part in various development process. Sox31 is a maternal factor supplied in the oocyte and starts its zygotic expression during mid-blastula transition (MBT). From gastrulation stage, it mainly resides in neural tissue. Ectopically expression of Sox31 mRNA leads to cyclopia, fusion eyes, or totally loss of anterior head structure, in accompany with severe notochord defects. Molecular markers indicate that forebrain tissue reduces sharply while the posterior neural tissue expands anteriorly. In addition, organizer specification is also suppressed. Oppositely, an antisense morpholino designed functionally knockdown Sox31 causes typically dorsalized phenotype and reversed central nervous system (CNS) anteroposterior (AP) patterning. Gain of function with chimeric construct, where Sox31 HMG DNA binding domain is fused to a transcription activation domain (VP16) or transcription suppression domain (EnR), suggests that Sox31 acts as a transcriptional suppressor in vivo. The expression of Bozozok (Dharma), a direct target gene of pre-MBT Wnt/β-catenin signal, is suppressed by Sox31. Thus, to unveil the relationship between Sox31 and β-catenin-related transcriptional activity, we designed Top/Fop luciferase assay in HEK293T cells, and found that Sox31 could indeed suppress Tcf/Lef-dependent transcriptional activity without influencing the stability of β-catenin. Moreover, post-MBT Wnt signal was reduced in Sox31 morphants corresponding to the suppressed hindbrain structure, while phenotypic defects caused by excessive Sox31 could be rescued by Wnt antagonist dkk1. Taken together, Sox31 functions as an essential CNS AP patterning determinant and coordinates the CNS AP patterning process with organizer specification.
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Affiliation(s)
- Shengnan Hu
- Laboratory of Molecular Cell Biology, Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Yamaguchi S, Hirano K, Nagata S, Tada T. Sox2 expression effects on direct reprogramming efficiency as determined by alternative somatic cell fate. Stem Cell Res 2011; 6:177-86. [DOI: 10.1016/j.scr.2010.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 09/10/2010] [Accepted: 09/28/2010] [Indexed: 01/02/2023] Open
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Gao F, Kwon SW, Zhao Y, Jin Y. PARP1 poly(ADP-ribosyl)ates Sox2 to control Sox2 protein levels and FGF4 expression during embryonic stem cell differentiation. J Biol Chem 2009; 284:22263-22273. [PMID: 19531481 DOI: 10.1074/jbc.m109.033118] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Transcription factors Oct4 and Sox2 are key players in maintaining the pluripotent state of embryonic stem cells (ESCs). Small changes in their levels disrupt normal expression of their target genes. However, it remains elusive how protein levels of Oct4 and Sox2 and expression of their target genes are precisely controlled in ESCs. Here we identify PARP1, a DNA-binding protein with an NAD+-dependent enzymatic activity, as a cofactor of Oct4 and Sox2 to regulate expression of their target gene FGF4. We demonstrate for the first time that PARP1 binds the FGF4 enhancer to positively regulate FGF4 expression. Our data show that PARP1 interacts with and poly(ADP-ribosyl)ates Sox2 directly, which may be a step required for dissociation and degradation of inhibitory Sox2 proteins from the FGF4 enhancer. When PARP1 activity is inhibited or absent, poly(ADP-ribosyl)ation of Sox2 decreases and association of Sox2 with FGF4 enhancers increases, accompanied by an elevated level of Sox2 proteins and reduced expression of FGF4. Significantly, specific knockdown of Sox2 expression by RNA interference can considerably abrogate the inhibitory effect of the poly(ADP-ribose) polymerase inhibitor on FGF4 expression. Interestingly, PARP1 deficiency does not affect undifferentiated ESCs but compromises cell survival and/or growth when ESCs are induced into differentiation. Addition of FGF4 can partially rescue the phenotypes caused by PARP1 deficiency during ESC differentiation. Taken together, this study uncovers new mechanisms through which Sox2 protein levels and FGF4 expression are dynamically regulated during ESC differentiation and adds a new member to the family of proteins regulating the properties of ESCs.
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Affiliation(s)
- Furong Gao
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences/Shanghai JiaoTong University School of Medicine, Shanghai 200025, China; Shanghai Stem Cell Institute, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China; Graduate School of Chinese Academy of Sciences, Beijing 100000, China
| | - Sung Won Kwon
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637
| | - Yingming Zhao
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637
| | - Ying Jin
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences/Shanghai JiaoTong University School of Medicine, Shanghai 200025, China; Shanghai Stem Cell Institute, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
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11
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Boer B, Bernadt CT, Desler M, Wilder PJ, Kopp JL, Rizzino A. Differential activity of the FGF-4 enhancer in F9 and P19 embryonal carcinoma cells. J Cell Physiol 2006; 208:97-108. [PMID: 16523502 DOI: 10.1002/jcp.20635] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Transcription factors Oct-3/4 and Sox2 behave as global regulators during mammalian embryogenesis. They work together by binding co-operatively to closely spaced HMG and POU motifs (HMG/POU cassettes). Recently, it was suggested that a critical Sox2:Oct-3/4 target gene, FGF-4, is expressed at lower levels in P19 than in F9 embryonal carcinoma (EC) cells, due to lower levels of Sox2 in P19 than in F9 cells. We tested this possibility to better understand how FGF-4 expression is modulated during development. Although we found that P19 EC cells express approximately 10-fold less FGF-4 mRNA than F9 EC cells, we determined that Sox2 levels do not differ markedly in F9 and P19 EC cells. We also determined that Sox2 and Oct-3/4 work together equally well in both EC cell lines. Moreover, in contrast to an earlier prediction based on in vitro binding studies, we demonstrate that the function of the HMG/POU cassettes of the FGF-4 and UTF1 genes does not differ significantly in these EC cell lines when tested in the context of a natural enhancer. Importantly, we determined that the FGF-4 promoter is highly responsive to a heterologous enhancer in both EC cell lines; whereas, the FGF-4 enhancer is 7- to 10-fold less active in P19 than in F9 EC cells. Because F9 and P19 EC cells are likely to represent cells at different stages of mammalian development, we suggest that this difference in FGF-4 enhancer activity may reflect a mechanism used to decrease, but not abolish, FGF-4 expression as the early embryo develops.
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MESH Headings
- Animals
- Blotting, Western
- Cell Line, Tumor
- Chromosomal Proteins, Non-Histone
- DNA-Binding Proteins/analysis
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Electrophoretic Mobility Shift Assay
- Enhancer Elements, Genetic/genetics
- Enhancer Elements, Genetic/physiology
- Fibroblast Growth Factor 4/analysis
- Fibroblast Growth Factor 4/genetics
- Fibroblast Growth Factor 4/physiology
- Gene Expression Regulation, Developmental/genetics
- Gene Expression Regulation, Neoplastic/genetics
- HMG-Box Domains/genetics
- Mice
- Neoplasms, Germ Cell and Embryonal/chemistry
- Neoplasms, Germ Cell and Embryonal/genetics
- Neoplasms, Germ Cell and Embryonal/pathology
- Neoplasms, Germ Cell and Embryonal/physiopathology
- Octamer Transcription Factor-3/analysis
- Octamer Transcription Factor-3/genetics
- Octamer Transcription Factor-3/physiology
- POU Domain Factors/genetics
- Promoter Regions, Genetic/genetics
- Promoter Regions, Genetic/physiology
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- SOXB1 Transcription Factors
- Trans-Activators/analysis
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transfection
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Affiliation(s)
- Brian Boer
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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Bani-Yaghoub M, Tremblay RG, Lei JX, Zhang D, Zurakowski B, Sandhu JK, Smith B, Ribecco-Lutkiewicz M, Kennedy J, Walker PR, Sikorska M. Role of Sox2 in the development of the mouse neocortex. Dev Biol 2006; 295:52-66. [PMID: 16631155 DOI: 10.1016/j.ydbio.2006.03.007] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 03/03/2006] [Accepted: 03/08/2006] [Indexed: 01/24/2023]
Abstract
The mammalian neocortex is established from neural stem and progenitor cells that utilize specific transcriptional and environmental factors to create functional neurons and astrocytes. Here, we examined the mechanism of Sox2 action during neocortical neurogenesis and gliogenesis. We established a robust Sox2 expression in neural stem and progenitor cells within the ventricular zone, which persisted until the cells exited the cell cycle. Overexpression of constitutively active Sox2 in neural progenitors resulted in upregulation of Notch1, recombination signal-sequence binding protein-J (RBP-J) and hairy enhancer of split 5 (Hes5) transcripts and the Sox2 high mobility group (HMG) domain seemed sufficient to confer these effects. While Sox2 overexpression permitted the differentiation of progenitors into astroglia, it inhibited neurogenesis, unless the Notch pathway was blocked. Moreover, neuronal precursors engaged a serine protease(s) to eliminate the overexpressed Sox2 protein and relieve the repression of neurogenesis. Glial precursors and differentiated astrocytes, on the other hand, maintained Sox2 expression until they reached a quiescent state. Sox2 expression was re-activated by signals that triggered astrocytic proliferation (i.e., injury, mitogenic and gliogenic factors). Taken together, Sox2 appears to act upstream of the Notch signaling pathway to maintain the cell proliferative potential and to ensure the generation of sufficient cell numbers and phenotypes in the developing neocortex.
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Affiliation(s)
- Mahmud Bani-Yaghoub
- Neurogenesis and Brain Repair Group, Neurobiology Program, Institute for Biological Sciences, National Research Council of Canada, 1200 Montreal Rd., Bldg. M-54, Ottawa, ON, Canada K1A 0R6.
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Bernadt CT, Nowling T, Rizzino A. Transcription factor Sox-2 inhibits co-activator stimulated transcription. Mol Reprod Dev 2005; 69:260-7. [PMID: 15349837 DOI: 10.1002/mrd.20168] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previous studies have shown that transcription of the fibroblast growth factor-4 (FGF-4) gene by early embryonic cells is dependent upon a powerful distal enhancer located 3 kb downstream of the transcription start site within the untranslated region of the last exon. The transcription factors Sox-2 and Oct-3 cooperatively bind to critical cis-regulatory elements within the enhancer to synergistically activate transcription. Moreover, the co-activator p300 can mediate the synergistic activity of Sox-2 and Oct-3, and p300 associates with the FGF-4 enhancer in vivo. Embryonal carcinoma (EC) cells have been used extensively as a model system to study the regulation of the FGF-4 gene during early development. Recently, it has been suggested that suboptimal levels of Sox-2 expression in F9 EC cells limit the transcription of the FGF-4 gene. The studies presented in this report argue that Sox-2 levels are not limiting in F9 EC cells. Moreover, overexpression of Sox-2 in F9 EC cells decreases FGF-4 promoter activity. In addition, overexpression of Sox-2 in these cells inhibits activation by the co-activators p300, CBP, and OCA-B in a manner that requires the transactivation domain of Sox-2. These findings suggest that Sox-2 levels in F9 EC cells are regulated carefully to avoid interference with the transcription of critical genes.
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Affiliation(s)
- Cory T Bernadt
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Bernadt CT, Nowling T, Wiebe MS, Rizzino A. NF-Y behaves as a bifunctional transcription factor that can stimulate or repress the FGF-4 promoter in an enhancer-dependent manner. Gene Expr 2005; 12:193-212. [PMID: 16128003 PMCID: PMC6009113 DOI: 10.3727/000000005783992052] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
NF-Y is a bifunctional transcription factor capable of activating or repressing transcription. NF-Y specifically recognizes CCAAT box motifs present in many eukaryotic promoters. The mechanisms involved in regulating its activity are poorly understood. Previous studies have shown that the FGF-4 promoter is regulated positively by its CCAAT box and NF-Y in embryonal carcinoma (EC) cells where the distal enhancer of the FGF-4 gene is active. Here, we demonstrate that the CCAAT box functions as a negative cis-regulatory element when cis-regulatory elements of the FGF-4 enhancer are disrupted, or after EC cells differentiate and the FGF-4 enhancer is inactivated. We also demonstrate that NF-Y mediates the repression of the CCAAT box and that NF-Y associates with the endogenous FGF-4 gene in both EC cells and EC-differentiated cells. Importantly, we also determined that the orientation and the position of the CCAAT box are critical for its role in regulating the FGF-4 promoter. Together, these studies demonstrate that the distal enhancer of the FGF-4 gene determines whether the CCAAT box of the FGF-4 promoter functions as a positive or a negative cis-regulatory element. In addition, these studies are consistent with NF-Y playing an architectural role in its regulation of the FGF-4 promoter.
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Affiliation(s)
- Cory T. Bernadt
- *Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-6805
- †Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-6805
| | - Tamara Nowling
- *Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-6805
| | - Matthew S. Wiebe
- *Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-6805
- †Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-6805
| | - Angie Rizzino
- *Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-6805
- †Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-6805
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Kunath T, Strumpf D, Rossant J. Early trophoblast determination and stem cell maintenance in the mouse--a review. Placenta 2004; 25 Suppl A:S32-8. [PMID: 15033304 DOI: 10.1016/j.placenta.2004.01.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Revised: 01/03/2004] [Accepted: 01/05/2004] [Indexed: 11/18/2022]
Abstract
The first priority of a mammalian embryo is to establish an intimate relationship with its mother. This is accomplished by precocious differentiation of the trophoblast lineage, which mediates uterine implantation and initiates the process of placentation. Surprisingly little is known about the molecular mechanisms that drive trophectoderm differentiation from the equipotent blastomeres of the morula. Somewhat more is known about the maintenance of trophoblast stem cells, once this lineage has been established. The first half of this review will focus on determination of the mouse trophoblast lineage and the second half will discuss the maintenance of trophoblast stem cells.
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Affiliation(s)
- T Kunath
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Canada M5G 1X5.
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16
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Luster TA, Rizzino A. Regulation of the FGF-4 gene by a complex distal enhancer that functions in part as an enhanceosome. Gene 2004; 323:163-72. [PMID: 14659890 DOI: 10.1016/j.gene.2003.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The exact mechanisms by which enhancers regulate transcription are currently under investigation. For some genes, activation is accomplished by an intricate array of enhancer cis-regulatory elements that direct the assembly of a gene-specific activation complex known as an "enhanceosome". Transcription of the fibroblast growth factor-4 (FGF-4) gene during early development is controlled by a powerful distal enhancer located 3 kb downstream of the transcription start site within the 3' untranslated region of the gene. Previous studies have shown that FGF-4 enhancer function is mediated by at least three critical positive cis-regulatory elements: an HMG, a POU, and a GT-box motif, which bind the transcription factors Sox-2, Oct-3, and Sp1/Sp3, respectively. In this study, we identify a second essential HMG motif within the FGF-4 enhancer that binds the transcription factor Sox-2. Moreover, we demonstrate that spatial alignment of the new HMG motif, relative the other enhancer cis-regulatory elements, is important. Based on findings presented in this report, and work published earlier, we propose that the previously identified core HMG and POU cis-regulatory elements of the FGF-4 enhancer are dependent on one another and function in an enhanceosome-like manner. In contrast, the HMG motif identified in this study is only partially dependent on the other enhancer cis-regulatory elements for its function.
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Affiliation(s)
- Troy A Luster
- Eppley Institute for the Research in Cancer and Allied Diseases, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-6805, USA
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17
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Wiebe MS, Nowling TK, Rizzino A. Identification of novel domains within Sox-2 and Sox-11 involved in autoinhibition of DNA binding and partnership specificity. J Biol Chem 2003; 278:17901-11. [PMID: 12637543 DOI: 10.1074/jbc.m212211200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sox transcription factors play key regulatory roles throughout development, binding DNA through a consensus (A/T)(A/T)CAA(A/T)G sequence. Although many different Sox proteins bind to this sequence, it has been observed that gene regulatory elements are commonly responsive to only a small subset of the entire family, implying that regulatory mechanisms exist to permit selective DNA binding and/or transactivation by Sox family members. To identify and explore the mechanisms modulating gene activation by Sox proteins further, we compared the function of Sox-2 and Sox-11. This led to the discovery that Sox proteins are regulated differentially at multiple levels, including transactivation, protein partnerships with Pit-Oct-Unc (POU) transcription factors, and DNA binding autoregulation. Specifically, we determined that Sox-11 activates transcription more strongly than Sox-2 and that the transactivation domain of Sox-11 is primarily responsible for this capability. Additionally, we demonstrate that the Sox-11 DNA binding domain is responsible for selective cooperation with the POU factor Brn-2. This requirement cannot be replaced by the DNA binding domain of Sox-2, indicating that the DNA binding domain of Sox proteins is critical for Sox-POU partnerships. Interestingly, we have also determined that a conserved domain of Sox-11 has the novel capability of autoinhibiting its ability to bind DNA in vitro and to activate gene expression in vivo. Our findings suggest that the autoinhibitory domain can repress promiscuous binding of Sox-11 to DNA and plays an important role in regulating the recruitment of Sox-11 to specific genes.
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Affiliation(s)
- Matthew S Wiebe
- Eppley Institute for Research in Cancer and Allied Diseases and the Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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18
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Nowling T, Bernadt C, Johnson L, Desler M, Rizzino A. The co-activator p300 associates physically with and can mediate the action of the distal enhancer of the FGF-4 gene. J Biol Chem 2003; 278:13696-705. [PMID: 12488456 DOI: 10.1074/jbc.m207567200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Distal enhancers commonly regulate gene expression. However, the mechanisms of transcriptional mediation by distal enhancers remain largely unknown. To better understand distal enhancer-mediated transcription, we examined the regulation of the FGF-4 gene. The FGF-4 gene is regulated during early development by a powerful distal enhancer located downstream of the promoter in exon 3. Sox-2 and Oct-3 bind to the enhancer and are required for the activation of the FGF-4 gene. Previously, we implicated the co-activator p300 as a mediator of Sox-2/Oct-3 synergistic activation of a heterologous promoter, suggesting that p300 may play a role in mediating enhancer activation of the FGF-4 gene. In this study, we provide both functional and physical evidence that p300 plays an important role in the action of the FGF-4 enhancer. Specifically, we show that E1a, but not a mutant form of E1a that is unable to bind p300, inhibits enhancer activation of the FGF-4 promoter. We also demonstrate that Gal4/p300 fusion proteins can stimulate the FGF-4 promoter when bound to the FGF-4 enhancer. Additionally, we present evidence that p300 mediation of the FGF-4 enhancer requires acetyltransferase activity. Importantly, we also show that Sox-2 and p300 are physically associated with the endogenous FGF-4 enhancer but weakly associated with the endogenous FGF-4 promoter. These results are consistent with a model of transitory interaction between the distal enhancer and the FGF-4 promoter. Our results also suggest that intragenic distal enhancers may use mechanisms that differ from extragenic distal enhancers.
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Affiliation(s)
- Tamara Nowling
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198, USA
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19
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Abstract
Embryonic stem (ES) cells are pluripotent stem cells that differentiate both in vitro and in vivo into cell types derived from each of the three embryonic germ layers. ES cells and their close relatives, embryonal carcinoma (EC) cells and embryonic germ (EG) cells, have been used extensively as model systems for studying early mammalian development. This work has led to important insights into the mechanisms that control embryogenesis at the molecular and cellular levels. This chapter focuses on the use of ES cells as an in vitro model system for studying cellular differentiation and reviews several areas where important progress has been made. Impressive progress has been made in the isolation and characterization of ES cells from many species, including humans. Significant progress has also been made in the development of culture conditions that help direct the differentiation of ES cells to specific cell types that form during myogenesis, angiogenesis, hematopoiesis, neurogenesis, and cardiogenesis. The ability to inactivate virtually any gene in ES cells by gene targeting has vastly improved our understanding of the roles played by specific genes at the cellular and organismic levels. Moreover, ES cells and EC cells have been used widely to investigate how specific genes are turned on and turned off in the course of differentiation. In this connection, DNA array technology has been used to identify genes regulated when ES cells differentiate. The final section of this chapter discusses how work with ES cells is shaping our understanding of stem cells, mammalian development, and cell replacement therapy.
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Affiliation(s)
- Angie Rizzino
- Eppley Institute for Cancer Research and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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20
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Johnson LR, Johnson TK, Desler M, Luster TA, Nowling T, Lewis RE, Rizzino A. Effects of B-Myb on gene transcription: phosphorylation-dependent activity ans acetylation by p300. J Biol Chem 2002; 277:4088-97. [PMID: 11733503 DOI: 10.1074/jbc.m105112200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcription factor B-Myb is a cell-cycle regulated phosphoprotein involved in cell cycle progression through the transcriptional regulation of many genes. In this study, we show that the promoter of the fibroblast growth factor-4 (FGF-4) gene is strongly activated by B-Myb in HeLa cells and it can serve as a novel diagnostic tool for assessing B-Myb activity. Specifically, B-Myb deletion mutants were examined and domains of B-Myb required for activation of the FGF-4 promoter were identified. Using phosphorylation-deficient mutant forms of B-Myb, we also show that phosphorylation is essential for B-Myb activity. Moreover, a mutant form of B-Myb, which lacks all identified phosphorylation sites and which has little activity, can function as a dominant-negative and suppress wild-type B-Myb activity. Acetylation is another post-translational modification known to affect the activity of other Myb family members. We show that B-Myb is acetylated by the co-activator p300. We also show that the bromo and histone acetyltransferase domains of p300 are sufficient to interact with and acetylate B-Myb. These data indicate that phosphorylation of B-Myb is an essential modification for activity and that acetylation of B-Myb may play a role in B-Myb activity.
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Affiliation(s)
- Lance R Johnson
- Eppley Institute for Research in Cancer and Allied Diseases, Department of Pathology University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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21
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Abstract
The induction of sensory organ placodes, in particular the lens placode, represents the paradigm for induction. We show that medaka Sox3 is expressed in the neuroectoderm and in the placodes of all sensory organs prior to placode formation and subsequently in placode-derived tissues. Ectopic Sox3 expression leads to ectopic expression of Pax6 and Eya1 in embryonic ectoderm and causes ectopic lens and otic vesicle formation. The descendants of cells ectopically expressing Sox3-mRNA contribute to ectopic lens tissue. This suggests a permissive role for Sox3 in establishing a placodal competence. In addition, ectopic Sox3 expression leads to the dysgenesis of the endogenous sensory organs. Both effects of ectopic Sox3 expression can be separated by ectopic expression of a truncated Sox3 variant depending on its expression level. Our data suggests that Sox3 is a permissive factor for sensory placode formation and plays an important role in sensory organ development.
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Affiliation(s)
- R W Köster
- SFB 271 Junior Group, c/o Max-Planck-Institut for Biophysical Chemistry, Am Fassberg, 37077, Göttingen, Germany
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22
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Wiebe MS, Wilder PJ, Kelly D, Rizzino A. Isolation, characterization, and differential expression of the murine Sox-2 promoter. Gene 2000; 246:383-93. [PMID: 10767561 DOI: 10.1016/s0378-1119(00)00086-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sox proteins are expressed at many stages of development and in numerous tissues. The transcription factor Sox-2 is first expressed throughout the inner cell mass and subsequently becomes localized to the primitive ectoderm, developing central nervous system, and the lens. Sox-2 is also highly expressed in F9 embryonal carcinoma cells, but becomes undetectable following differentiation of these cells. In this study, we have isolated, sequenced, and performed the first characterization of the Sox-2 promoter of any species. Approximately 2kb of the Sox-2 5'-flanking region has been sequenced and the primary transcription start site mapped by primer extension analysis. Additionally, two positive regulatory regions within the promoter region have been identified. We also show that expression of Sox-2 promoter/reporter gene constructs is reduced in differentiated EC cells as compared to their undifferentiated counterparts. Furthermore, we have identified a consensus inverted CCAAT box motif present in the Sox-2 promoter. Mutagenesis of this site significantly reduces the expression of Sox-2 promoter/reporter constructs. We also demonstrate that this CCAAT box motif can bind the trimeric transcription factor NF-Y.
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Affiliation(s)
- M S Wiebe
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-6805, USA
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23
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Nowling TK, Johnson LR, Wiebe MS, Rizzino A. Identification of the transactivation domain of the transcription factor Sox-2 and an associated co-activator. J Biol Chem 2000; 275:3810-8. [PMID: 10660531 DOI: 10.1074/jbc.275.6.3810] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation domain of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both approaches demonstrated that Sox-2 contains a transactivation domain in its C-terminal half, containing a serine-rich region and the C terminus. We also determined that the viral oncoprotein E1a inhibits the ability of the Gal4/Sox-2 fusion protein to transactivate, as well as the transcriptional activation mediated by the combined action of Sox-2 and Oct-3. In contrast, a mutant form of E1a, unable to bind p300, lacks both of these effects. Importantly, we determined that p300 overcomes the inhibitory effects of E1a in both assays. Together, these findings suggest that Sox-2 mediates its effects, at least in part, through the co-activator p300.
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Affiliation(s)
- T K Nowling
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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24
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Bergstrom DE, Young M, Albrecht KH, Eicher EM. Related function of mouse SOX3, SOX9, and SRY HMG domains assayed by male sex determination. Genesis 2000. [DOI: 10.1002/1526-968x(200011/12)28:3/4<111::aid-gene40>3.0.co;2-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Lamb KA, Rizzino A. Effects of differentiation on the transcriptional regulation of the FGF-4 gene: critical roles played by a distal enhancer. Mol Reprod Dev 1998; 51:218-24. [PMID: 9740330 DOI: 10.1002/(sici)1098-2795(199810)51:2<218::aid-mrd12>3.0.co;2-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Embryonal carcinoma (EC) cells are used widely as a model system for studying the expression of developmentally regulated genes, in particular genes that are regulated at the transcriptional level when EC cells differentiate. This review focuses on the molecular mechanisms that govern the transcription of the fibroblast growth factor-4 (FGF-4) gene, which appears to be the first FGF expressed during mammalian development. Interest in this gene has increased considerably with the finding that FGF-4 is essential for mammalian embryogenesis. The FGF-4 gene has also generated considerable interest because it is inhibited at the transcriptional level when EC cells undergo differentiation and because this gene is regulated by a powerful distal enhancer located 3 kb downstream of the transcription start site in the last exon of the gene. Hence, study of the FGF-4 gene is likely to shed light on the molecular mechanisms by which distal enhancers regulate gene expression. In addition to being regulated by the downstream enhancer, the expression of this gene is influenced by a regulatory region located just upstream of the transcription start site, which contains two Sp1 motifs and a CCAAT box motif. Examination of the downstream enhancer has identified three functional cis-regulatory elements: a high mobility group (HMG) protein binding motif, an octamer binding motif, and an Sp1 motif, which are likely to bind Sox-2, Oct-3, and Sp1/Sp3, respectively, in vivo. Interestingly, Sox-2 and Oct-3 expression, like FGF-4 expression, decreases when EC cells differentiate, which suggests that the loss of these transcription factors is responsible, at least in part, for the transcriptional turn-off of the FGF-4 gene. In view of these and other findings, we present a model for the differential expression of the FGF-4 gene that includes not only the contributions of specific transcription factors, but also the contribution of chromatin structure before and after differentiation.
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Affiliation(s)
- K A Lamb
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198-6805, USA
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