1
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Thomas ME, Qi W, Walsh MP, Ma J, Westover T, Abdelhamed S, Ezzell LJ, Rolle C, Xiong E, Rosikiewicz W, Xu B, Loughran AJ, Pruett-Miller SM, Janke LJ, Klco JM. Functional characterization of cooperating MGA mutations in RUNX1::RUNX1T1 acute myeloid leukemia. Leukemia 2024; 38:991-1002. [PMID: 38454121 PMCID: PMC11073986 DOI: 10.1038/s41375-024-02193-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
MGA (Max-gene associated) is a dual-specificity transcription factor that negatively regulates MYC-target genes to inhibit proliferation and promote differentiation. Loss-of-function mutations in MGA have been commonly identified in several hematological neoplasms, including acute myeloid leukemia (AML) with RUNX1::RUNX1T1, however, very little is known about the impact of these MGA alterations on normal hematopoiesis or disease progression. We show that representative MGA mutations identified in patient samples abolish protein-protein interactions and transcriptional activity. Using a series of human and mouse model systems, including a newly developed conditional knock-out mouse strain, we demonstrate that loss of MGA results in upregulation of MYC and E2F targets, cell cycle genes, mTOR signaling, and oxidative phosphorylation in normal hematopoietic cells, leading to enhanced proliferation. The loss of MGA induces an open chromatin state at promoters of genes involved in cell cycle and proliferation. RUNX1::RUNX1T1 expression in Mga-deficient murine hematopoietic cells leads to a more aggressive AML with a significantly shortened latency. These data show that MGA regulates multiple pro-proliferative pathways in hematopoietic cells and cooperates with the RUNX1::RUNX1T1 fusion oncoprotein to enhance leukemogenesis.
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Affiliation(s)
- Melvin E Thomas
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Wenqing Qi
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Michael P Walsh
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Jing Ma
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Tamara Westover
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Sherif Abdelhamed
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Lauren J Ezzell
- Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Chandra Rolle
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Emily Xiong
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Wojciech Rosikiewicz
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Beisi Xu
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Allister J Loughran
- Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Shondra M Pruett-Miller
- Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Laura J Janke
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA
| | - Jeffery M Klco
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 342, Memphis, TN, 38105, USA.
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2
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Klco J, Thomas M, Qi W, Walsh M, Ma J, Westover T, Abdelhamed S, Ezzell L, Rolle C, Xiong E, Rosikiewicz W, Xu B, Pruett-Miller S, Loughran A, Janke L. Functional Characterization of Cooperating MGA Mutations in RUNX1::RUNX1T1 Acute Myeloid Leukemia. RESEARCH SQUARE 2023:rs.3.rs-3315059. [PMID: 37790524 PMCID: PMC10543392 DOI: 10.21203/rs.3.rs-3315059/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
MGA (Max-gene associated) is a dual-specificity transcription factor that negatively regulates MYC-target genes to inhibit proliferation and promote differentiation. Loss-of-function mutations in MGA have been commonly identified in several hematological neoplasms, including acute myeloid leukemia (AML) with RUNX1::RUNX1T1, however, very little is known about the impact of these MGA alterations on normal hematopoiesis or disease progression. We show that representative MGA mutations identified in patient samples abolish protein-protein interactions and transcriptional activity. Using a series of human and mouse model systems, including a newly developed conditional knock-out mouse strain, we demonstrate that loss of MGA results in upregulation of MYC and E2F targets, cell cycle genes, mTOR signaling, and oxidative phosphorylation in normal hematopoietic cells, leading to enhanced proliferation. The loss of MGA induces an open chromatin state at promotors of genes involved in cell cycle and proliferation. RUNX1::RUNX1T1 expression in Mga-deficient murine hematopoietic cells leads to a more aggressive AML with a significantly shortened latency. These data show that MGA regulates multiple pro-proliferative pathways in hematopoietic cells and cooperates with the RUNX1::RUNX1 T1 fusion oncoprotein to enhance leukemogenesis.
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Affiliation(s)
| | | | | | | | - Jing Ma
- St. Jude Children's Research Hospital
| | | | | | | | | | | | | | - Beisi Xu
- St Jude Children's Research Hospital
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3
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Li Y, Huang Y, Li B, Yang K. Roles of E2F family members in the diagnosis and prognosis of head and neck squamous cell carcinoma. BMC Med Genomics 2023; 16:38. [PMID: 36855110 PMCID: PMC9976507 DOI: 10.1186/s12920-023-01470-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide. E2Fs are a group of transcription factors involved in the carcinogenesis and progression of various cancers. However, the exact roles of each member of E2F family in the development and progression of HNSCC are still unknown. METHODS RNASeq and clinical follow-up information were extracted from The Cancer Genome Atlas (TCGA). The expressions of E2Fs and their roles in HNSCC progression were explored using the R software and the cBioPortal database. RESULTS Our results showed that the mRNA levels of E2Fs were significantly higher in HNSCC tumors than in normal tissues. E2F1, E2F3, E2F4, E2F6, and E2F7 were identified as reliable diagnostic markers. E2Fs (except for E2F3) expressions were closely related to the clinical features (excluding metastasis) of HNSCC. High E2F6 mRNA expression was an independent risk factor for the OS of female HNSCC patients. In addition, high E2F4 expression could lead to poor prognosis in HNSCC in both males and females, high expressions of E2F5, E2F6, and E2F7 were associated with poor OS of female HNSCC patients, while high E2F2 and E2F8 expressions were positively correlated with the OS of male HNSCC patients. Interestingly, E2Fs expressions had stronger associations with immune cell infiltrations in male HNSCC patients than in female HNSCC patients. CONCLUSION The expressions of E2Fs were found to be correlated with the progression of HNSCC. E2F1, E2F3, E2F4, E2F6, and E2F7 could be good diagnostic molecules for HNSCC. In addition, E2F6 was an independent risk factor for the prognosis of female HNSCC patients.
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Affiliation(s)
- Yaoxu Li
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, No.1, Youyi Road, Yuzhong District, 400016, Chongqing, China
| | - Yinpei Huang
- Department of Otorhinolaryngology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Bing Li
- Department of Otorhinolaryngology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China.
| | - Kai Yang
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, No.1, Youyi Road, Yuzhong District, 400016, Chongqing, China.
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4
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Lingg L, Rottenberg S, Francica P. Meiotic Genes and DNA Double Strand Break Repair in Cancer. Front Genet 2022; 13:831620. [PMID: 35251135 PMCID: PMC8895043 DOI: 10.3389/fgene.2022.831620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/02/2022] [Indexed: 12/16/2022] Open
Abstract
Tumor cells show widespread genetic alterations that change the expression of genes driving tumor progression, including genes that maintain genomic integrity. In recent years, it has become clear that tumors frequently reactivate genes whose expression is typically restricted to germ cells. As germ cells have specialized pathways to facilitate the exchange of genetic information between homologous chromosomes, their aberrant regulation influences how cancer cells repair DNA double strand breaks (DSB). This drives genomic instability and affects the response of tumor cells to anticancer therapies. Since meiotic genes are usually transcriptionally repressed in somatic cells of healthy tissues, targeting aberrantly expressed meiotic genes may provide a unique opportunity to specifically kill cancer cells whilst sparing the non-transformed somatic cells. In this review, we highlight meiotic genes that have been reported to affect DSB repair in cancers derived from somatic cells. A better understanding of their mechanistic role in the context of homology-directed DNA repair in somatic cancers may provide useful insights to find novel vulnerabilities that can be targeted.
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Affiliation(s)
- Lea Lingg
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Cancer Therapy Resistance Cluster, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Sven Rottenberg
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Cancer Therapy Resistance Cluster, Department for BioMedical Research, University of Bern, Bern, Switzerland
- Bern Center for Precision Medicine, University of Bern, Bern, Switzerland
- *Correspondence: Sven Rottenberg, ; Paola Francica,
| | - Paola Francica
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Cancer Therapy Resistance Cluster, Department for BioMedical Research, University of Bern, Bern, Switzerland
- *Correspondence: Sven Rottenberg, ; Paola Francica,
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5
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Mochizuki K, Sharif J, Shirane K, Uranishi K, Bogutz AB, Janssen SM, Suzuki A, Okuda A, Koseki H, Lorincz MC. Repression of germline genes by PRC1.6 and SETDB1 in the early embryo precedes DNA methylation-mediated silencing. Nat Commun 2021; 12:7020. [PMID: 34857746 PMCID: PMC8639735 DOI: 10.1038/s41467-021-27345-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 11/08/2021] [Indexed: 01/10/2023] Open
Abstract
Silencing of a subset of germline genes is dependent upon DNA methylation (DNAme) post-implantation. However, these genes are generally hypomethylated in the blastocyst, implicating alternative repressive pathways before implantation. Indeed, in embryonic stem cells (ESCs), an overlapping set of genes, including germline "genome-defence" (GGD) genes, are upregulated following deletion of the H3K9 methyltransferase SETDB1 or subunits of the non-canonical PRC1 complex PRC1.6. Here, we show that in pre-implantation embryos and naïve ESCs (nESCs), hypomethylated promoters of germline genes bound by the PRC1.6 DNA-binding subunits MGA/MAX/E2F6 are enriched for RING1B-dependent H2AK119ub1 and H3K9me3. Accordingly, repression of these genes in nESCs shows a greater dependence on PRC1.6 than DNAme. In contrast, GGD genes are hypermethylated in epiblast-like cells (EpiLCs) and their silencing is dependent upon SETDB1, PRC1.6/RING1B and DNAme, with H3K9me3 and DNAme establishment dependent upon MGA binding. Thus, GGD genes are initially repressed by PRC1.6, with DNAme subsequently engaged in post-implantation embryos.
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Affiliation(s)
- Kentaro Mochizuki
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jafar Sharif
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Kenjiro Shirane
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
| | - Kousuke Uranishi
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Aaron B Bogutz
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sanne M Janssen
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ayumu Suzuki
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Akihiko Okuda
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
- Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo ward, Chiba, Japan
| | - Matthew C Lorincz
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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6
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Wu SC, Münger K. Role and Clinical Utility of Cancer/Testis Antigens in Head and Neck Squamous Cell Carcinoma. Cancers (Basel) 2021; 13:cancers13225690. [PMID: 34830845 PMCID: PMC8616139 DOI: 10.3390/cancers13225690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/03/2021] [Accepted: 11/11/2021] [Indexed: 12/15/2022] Open
Abstract
Cancer/testis (CT) antigens exhibit selective expression predominantly in immunoprivileged tissues in non-pathological contexts but are aberrantly expressed in diverse cancers. Due to their expression pattern, they have historically been attractive targets for immunotherapies. A growing number of studies implicate CT antigens in almost all hallmarks of cancer, suggesting that they may act as cancer drivers. CT antigens are expressed in head and neck squamous cell carcinomas. However, their role in the pathogenesis of these cancers remains poorly studied. Given that CT antigens hold intriguing potential as therapeutic targets and as biomarkers for prognosis and that they can provide novel insights into oncogenic mechanisms, their further study in the context of head and squamous cell carcinoma is warranted.
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Affiliation(s)
- Sharon Changshan Wu
- Molecular Microbiology Program, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA;
| | - Karl Münger
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
- Correspondence:
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7
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Dahlet T, Truss M, Frede U, Al Adhami H, Bardet AF, Dumas M, Vallet J, Chicher J, Hammann P, Kottnik S, Hansen P, Luz U, Alvarez G, Auclair G, Hecht J, Robinson PN, Hagemeier C, Weber M. E2F6 initiates stable epigenetic silencing of germline genes during embryonic development. Nat Commun 2021; 12:3582. [PMID: 34117224 PMCID: PMC8195999 DOI: 10.1038/s41467-021-23596-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/04/2021] [Indexed: 11/24/2022] Open
Abstract
In mouse development, long-term silencing by CpG island DNA methylation is specifically targeted to germline genes; however, the molecular mechanisms of this specificity remain unclear. Here, we demonstrate that the transcription factor E2F6, a member of the polycomb repressive complex 1.6 (PRC1.6), is critical to target and initiate epigenetic silencing at germline genes in early embryogenesis. Genome-wide, E2F6 binds preferentially to CpG islands in embryonic cells. E2F6 cooperates with MGA to silence a subgroup of germline genes in mouse embryonic stem cells and in embryos, a function that critically depends on the E2F6 marked box domain. Inactivation of E2f6 leads to a failure to deposit CpG island DNA methylation at these genes during implantation. Furthermore, E2F6 is required to initiate epigenetic silencing in early embryonic cells but becomes dispensable for the maintenance in differentiated cells. Our findings elucidate the mechanisms of epigenetic targeting of germline genes and provide a paradigm for how transient repression signals by DNA-binding factors in early embryonic cells are translated into long-term epigenetic silencing during mouse development. DNA methylation targets CpG island promoters of germline genes to repress their expression in mouse somatic cells. Here the authors show that a transcription factor E2F6 is required to target CpG island DNA methylation and epigenetic silencing to germline genes during early mouse development.
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Affiliation(s)
- Thomas Dahlet
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Matthias Truss
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Ute Frede
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Hala Al Adhami
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Anaïs F Bardet
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Michael Dumas
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Judith Vallet
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade, CNRS, University of Strasbourg, Strasbourg, France
| | - Philippe Hammann
- Plateforme protéomique Strasbourg Esplanade, CNRS, University of Strasbourg, Strasbourg, France
| | - Sarah Kottnik
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Hansen
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Uschi Luz
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gonzalo Alvarez
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ghislain Auclair
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France
| | - Jochen Hecht
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité Universitätsmedizin Berlin, Berlin, Germany.,Centre for Genomic Regulation, Barcelona, Spain
| | - Peter N Robinson
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité Universitätsmedizin Berlin, Berlin, Germany.,Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Christian Hagemeier
- Pediatric Oncology, Labor für Pädiatrische Molekularbiologie, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Michael Weber
- University of Strasbourg, Strasbourg, France. .,CNRS UMR7242, Biotechnology and Cell Signaling, Illkirch, France.
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8
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Gantchev J, Martínez Villarreal A, Gunn S, Zetka M, Ødum N, Litvinov IV. The ectopic expression of meiCT genes promotes meiomitosis and may facilitate carcinogenesis. Cell Cycle 2020; 19:837-854. [PMID: 32223693 DOI: 10.1080/15384101.2020.1743902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cancer meiomitosis is defined as the concurrent activation of both mitotic and meiotic machineries in neoplastic cells that confer a selective advantage together with increased genomic instability. MeiCT (meiosis-specific cancer/testis) genes that perform specialized functions in the germline events required for the first meiotic division are ectopically expressed in several cancers. Here we describe the expression profiles of meiCT genes and proteins across a number of cancers and review the proposed mechanisms that increase aneuploidy and elicit reduction division in polyploid cells. These mechanisms are centered on the overexpression and function of meiCT proteins in cancers under various conditions that includes a response to genotoxic stress. Since meiCT genes are transcriptionally repressed in somatic cells, their target offers a promising therapeutic approach with limited toxicity to healthy tissues. Throughout the review, we provide a detailed description of the roles for each gene in the context of meiosis and we discuss proposed functions and outcomes resulting from their ectopic reactivation in cancer.
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Affiliation(s)
- Jennifer Gantchev
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | | | - Scott Gunn
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Monique Zetka
- Department of Biology, McGill University, Montreal, QC, Canada
| | - Neils Ødum
- Department of Microbiology and Immunology, The University of Copenhagen, Copenhagen, Denmark
| | - Ivan V Litvinov
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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9
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Lafta IJ, Kudhair BK, Alabid NN. Characterization of the major human STAG3 variants using some proteomics and bioinformatics assays. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2020. [DOI: 10.1186/s43042-020-0051-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abstract
Background
STAG3 is the meiotic component of cohesin and a member of the Cancer Testis Antigen (CTA) family. This gene has been found to be overexpressed in many types of cancer, and recently, its variants have been implicated in other disorders and many human diseases. Therefore, this study aimed to analyze the major variants of STAG3. Western blot (WB) and immunoprecipitation (IP) assays were performed using two different anti-STAG3 antibodies that targeted the relevant protein in MCF-7, T-47D, MDA-MB-468, and MDA-MB-231 breast cancer cells with Jurkat and MCF-10A cells as positive and negative controls, respectively. In silico analyses were searched to study the major isoforms.
Results
WB and IP assays revealed two abundant polypeptides < 191 kDa and ~ 75 kDa in size. Specific bioinformatics tools successfully determined the three-dimensional (3-D) structure, the subcellular localization, and the secondary structures of the isoforms. Furthermore, some of the physicochemical properties of the STAG3 proteins were also determined.
Conclusions
The results of this study revealed the power of applying the biological techniques (WB and IP) with the bioinformatics assays and the possibility of their exploitation in understanding diseased genes. Exploring the major variants of STAG3 at the protein level could help decipher some disorders associated with their occurrence, along with designing drugs effective at least for some relevant diseases.
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10
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Stielow B, Finkernagel F, Stiewe T, Nist A, Suske G. MGA, L3MBTL2 and E2F6 determine genomic binding of the non-canonical Polycomb repressive complex PRC1.6. PLoS Genet 2018; 14:e1007193. [PMID: 29381691 PMCID: PMC5806899 DOI: 10.1371/journal.pgen.1007193] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 02/09/2018] [Accepted: 01/09/2018] [Indexed: 02/02/2023] Open
Abstract
Diverse Polycomb repressive complexes 1 (PRC1) play essential roles in gene regulation, differentiation and development. Six major groups of PRC1 complexes that differ in their subunit composition have been identified in mammals. How the different PRC1 complexes are recruited to specific genomic sites is poorly understood. The Polycomb Ring finger protein PCGF6, the transcription factors MGA and E2F6, and the histone-binding protein L3MBTL2 are specific components of the non-canonical PRC1.6 complex. In this study, we have investigated their role in genomic targeting of PRC1.6. ChIP-seq analysis revealed colocalization of MGA, L3MBTL2, E2F6 and PCGF6 genome-wide. Ablation of MGA in a human cell line by CRISPR/Cas resulted in complete loss of PRC1.6 binding. Rescue experiments revealed that MGA recruits PRC1.6 to specific loci both by DNA binding-dependent and by DNA binding-independent mechanisms. Depletion of L3MBTL2 and E2F6 but not of PCGF6 resulted in differential, locus-specific loss of PRC1.6 binding illustrating that different subunits mediate PRC1.6 loading to distinct sets of promoters. Mga, L3mbtl2 and Pcgf6 colocalize also in mouse embryonic stem cells, where PRC1.6 has been linked to repression of germ cell-related genes. Our findings unveil strikingly different genomic recruitment mechanisms of the non-canonical PRC1.6 complex, which specify its cell type- and context-specific regulatory functions. Polycomb group proteins assemble in two major repressive multi-subunit complexes (PRC1 and PRC2), which play important roles in many physiological processes, including stem cell maintenance, differentiation, cell cycle control and cancer. In mammals, six different groups of PRC1 complexes exist (PRC1.1 to PRC1.6), which differ in their subunit composition. The mechanisms that target the different PRC1 complexes to specific genomic sites appear diverse and are poorly understood. In this study, we have investigated the genomic targeting mechanisms of the non-canonical PRC1.6 complex. In PRC1.6, the defining subunit PCGF6 is specifically associated with several proteins including the transcription factors MGA and E2F6, and the histone-binding protein L3MBTL2. We found that MGA is absolutely essential for targeting PRC1.6. MGA executes recruitment of PRC1.6 to its target sites through two distinct functions. On the one hand it acts as a sequence-specific DNA-binding factor; on the other hand it has a scaffolding function, which is independent of its DNA binding capacity. E2F6 and L3MBTL2 are also important in genomic targeting of PRC1.6 as they promote binding of PRC1.6 to different sets of genes associated with distinct functions. Our finding that different components specify loading of PRC1.6 to distinct sets of genes could establish a paradigm for other chromatin-associated complexes.
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Affiliation(s)
- Bastian Stielow
- Institute of Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - Florian Finkernagel
- Institute of Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - Thorsten Stiewe
- Genomics Core Facility, Center for Tumor Biology and Immunology (ZTI), Philipps-University of Marburg, Marburg, Germany
| | - Andrea Nist
- Genomics Core Facility, Center for Tumor Biology and Immunology (ZTI), Philipps-University of Marburg, Marburg, Germany
| | - Guntram Suske
- Institute of Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
- * E-mail:
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11
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Zheng A, Cao X, Zhong S. Pattern-based Search of Epigenomic Data Using GeNemo. J Vis Exp 2017. [PMID: 29053670 PMCID: PMC5752390 DOI: 10.3791/56136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Compared with the robust text-based search tools for genomic or RNA sequencing data, current methodologies for pattern-based searches of epigenomic and other functional genomic data are very limited. GeNemo is the first online search tool that accomplishes this goal. Users input their functional genomic data in the Browser Extensible Data (BED), Peaks, and bigWig formats, and may search for data in any of the three formats. Users may specify which types of datasets to search against, choosing from a variety of online datasets, with the Encyclopedia of DNA Elements (ENCODE) representing different epigenomic marks, transcriptional factor binding sites, and chromatin hypersensitivities or accessibilities in specific cell types, and developmental stages or species (mouse or human). GeNemo returns a list of genomic regions with matching patterns to the input data, which may be viewed in the browser as well as downloaded in the BED file format. The upgraded GeNemo has improved graphical display, has more robust interface, and is no longer prone to errors due to changes in the University of California, Santa Cruz (UCSC) genome browser. Troubleshooting steps for common problems are discussed. As the amount of functional genomic data is expanding exponentially, there is a critical need to develop and refine new bioinformatic tools such as GeNemo for data analyses and interpretation.
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Affiliation(s)
- Alvin Zheng
- Department of Bioengineering, University of California San Diego
| | - Xiaoyi Cao
- Department of Bioengineering, University of California San Diego
| | - Sheng Zhong
- Department of Bioengineering, University of California San Diego;
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12
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Yi F, Wang Z, Liu J, Zhang Y, Wang Z, Xu H, Li X, Bai N, Cao L, Song X. Structural Maintenance of Chromosomes protein 1: Role in Genome Stability and Tumorigenesis. Int J Biol Sci 2017; 13:1092-1099. [PMID: 28924389 PMCID: PMC5599913 DOI: 10.7150/ijbs.21206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 07/05/2017] [Indexed: 01/05/2023] Open
Abstract
SMC1 (Structural Maintenance of Chromosomes protein 1), well known as one of the SMC superfamily members, has been explored to function in many activities including chromosome dynamics, cell cycle checkpoint, DNA damage repair and genome stability. Upon being properly assembled as part of cohesin, SMC1 can be phosphorylated by ATM and mediate downstream DNA damage repair after ionizing irradiation. Abnormal gene expression or mutation of SMC1 can cause defect in the DNA damage repair pathway, which has been strongly associated with tumorigenesis. Here we focus to discuss SMC1's role in genome stability maintenance and tumorigenesis. Deciphering the underlying molecular mechanism can provide insight into novel strategies for cancer treatment.
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Affiliation(s)
- Fei Yi
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Zhuo Wang
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Jingwei Liu
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Ying Zhang
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Zhijun Wang
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Hongde Xu
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Xiaoman Li
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Ning Bai
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Liu Cao
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
| | - Xiaoyu Song
- Key Laboratory of Medical Cell Biology, Ministry of Education; Institute of Translational Medicine, China Medical University; Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, Shenyang, Liaoning Province, China
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13
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Zhao W, Tong H, Huang Y, Yan Y, Teng H, Xia Y, Jiang Q, Qin J. Essential Role for Polycomb Group Protein Pcgf6 in Embryonic Stem Cell Maintenance and a Noncanonical Polycomb Repressive Complex 1 (PRC1) Integrity. J Biol Chem 2017; 292:2773-2784. [PMID: 28049731 DOI: 10.1074/jbc.m116.763961] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/29/2016] [Indexed: 11/06/2022] Open
Abstract
The Polycomb group (PcG) proteins have an important role in controlling the expression of key genes implicated in embryonic development, differentiation, and decision of cell fates. Emerging evidence suggests that Polycomb repressive complexes 1 (PRC1) is defined by the six Polycomb group RING finger protein (Pcgf) paralogs, and Pcgf proteins can assemble into noncanonical PRC1 complexes. However, little is known about the precise mechanisms of differently composed noncanonical PRC1 in the maintenance of the pluripotent cell state. Here we disrupt the Pcgf genes in mouse embryonic stem cells by CRISPR-Cas9 and find Pcgf6 null embryonic stem cells display severe defects in self-renewal and differentiation. Furthermore, Pcgf6 regulates genes mostly involved in differentiation and spermatogenesis by assembling a noncanonical PRC1 complex PRC1.6. Notably, Pcgf6 deletion causes a dramatic decrease in PRC1.6 binding to target genes and no loss of H2AK119ub1. Thus, Pcgf6 is essential for recruitment of PRC1.6 to chromatin. Our results reveal a previously uncharacterized, H2AK119ub1-independent chromatin assembly associated with PRC1.6 complex.
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Affiliation(s)
- Wukui Zhao
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Huan Tong
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Yikai Huang
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Yun Yan
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Huajian Teng
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Yin Xia
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China, and
| | - Qing Jiang
- Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing 210008, China
| | - Jinzhong Qin
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China,
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14
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Mannini L, Cucco F, Quarantotti V, Amato C, Tinti M, Tana L, Frattini A, Delia D, Krantz ID, Jessberger R, Musio A. SMC1B is present in mammalian somatic cells and interacts with mitotic cohesin proteins. Sci Rep 2015; 5:18472. [PMID: 26673124 PMCID: PMC4682075 DOI: 10.1038/srep18472] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/18/2015] [Indexed: 01/02/2023] Open
Abstract
Cohesin is an evolutionarily conserved protein complex that plays a role in many biological processes: it ensures faithful chromosome segregation, regulates gene expression and preserves genome stability. In mammalian cells, the mitotic cohesin complex consists of two structural maintenance of chromosome proteins, SMC1A and SMC3, the kleisin protein RAD21 and a fourth subunit either STAG1 or STAG2. Meiotic paralogs in mammals were reported for SMC1A, RAD21 and STAG1/STAG2 and are called SMC1B, REC8 and STAG3 respectively. It is believed that SMC1B is only a meiotic-specific cohesin member, required for sister chromatid pairing and for preventing telomere shortening. Here we show that SMC1B is also expressed in somatic mammalian cells and is a member of a mitotic cohesin complex. In addition, SMC1B safeguards genome stability following irradiation whereas its ablation has no effect on chromosome segregation. Finally, unexpectedly SMC1B depletion impairs gene transcription, particularly at genes mapping to clusters such as HOX and PCDHB. Genome-wide analyses show that cluster genes changing in expression are enriched for cohesin-SMC1B binding.
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Affiliation(s)
- Linda Mannini
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Francesco Cucco
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Valentina Quarantotti
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Clelia Amato
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Mara Tinti
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Luigi Tana
- Azienda Ospedaliero Universitaria Pisana, U.O. Fisica Sanitaria, Pisa, Italy
| | - Annalisa Frattini
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Milan, Italy
- Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi dell’Insubria, Varese, Italy
| | - Domenico Delia
- Fondazione IRCCS Istituto Nazionale Tumori, Department of Experimental Oncology, Milan, Italy
| | - Ian D. Krantz
- Division of Human Genetics, The Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Antonio Musio
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy
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15
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Leseva M, Santostefano KE, Rosenbluth AL, Hamazaki T, Terada N. E2f6-mediated repression of the meiotic Stag3 and Smc1β genes during early embryonic development requires Ezh2 and not the de novo methyltransferase Dnmt3b. Epigenetics 2013; 8:873-84. [PMID: 23880518 PMCID: PMC3883790 DOI: 10.4161/epi.25522] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/12/2013] [Accepted: 06/24/2013] [Indexed: 12/31/2022] Open
Abstract
The E2f6 transcriptional repressor is an E2F-family member essential for the silencing of a group of meiosis-specific genes in somatic tissues. Although E2f6 has been shown to associate with both polycomb repressive complexes (PRC) and the methyltransferase Dnmt3b, the cross-talk between these repressive machineries during E2f6-mediated gene silencing has not been clearly demonstrated yet. In particular, it remains largely undetermined when and how E2f6 establishes repression of meiotic genes during embryonic development. We demonstrate here that the inactivation of a group of E2f6 targeted genes, including Stag3 and Smc1β, first occurs at the transition from mouse embryonic stem cells (ESCs) to epiblast stem cells (EpiSCs), which represent pre- and post-implantation stages, respectively. This process was accompanied by de novo methylation of their promoters. Of interest, despite a clear difference in DNA methylation status, E2f6 was similarly bound to the proximal promoter regions both in ESCs and EpiSCs. Neither E2f6 nor Dnmt3b overexpression in ESCs decreased meiotic gene expression or increased DNA methylation, indicating that additional factors are required for E2f6-mediated repression during the transition. When the SET domain of Ezh2, a core subunit of the PRC2 complex, was deleted, however, repression of Stag3 and Smc1β during embryoid body differentiation was largely impaired, indicating that the event required the enzymatic activity of Ezh2. In addition, repression of Stag3 and Smc1β occurred in the absence of Dnmt3b. The data presented here suggest a primary role of PRC2 in E2f6-mediated gene silencing of the meiotic genes.
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Affiliation(s)
- Milena Leseva
- Department of Pathology; University of Florida College of Medicine; Gainesville, FL USA
| | | | - Amy L Rosenbluth
- Department of Pathology; University of Florida College of Medicine; Gainesville, FL USA
| | - Takashi Hamazaki
- Department of Pathology; University of Florida College of Medicine; Gainesville, FL USA
- Department of Pediatrics; Osaka City University Graduate School of Medicine; Osaka, Japan
| | - Naohiro Terada
- Department of Pathology; University of Florida College of Medicine; Gainesville, FL USA
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16
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Strunnikov A. Cohesin complexes with a potential to link mammalian meiosis to cancer. CELL REGENERATION 2013; 2:4. [PMID: 25408876 PMCID: PMC4230521 DOI: 10.1186/2045-9769-2-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/16/2013] [Indexed: 01/28/2023]
Abstract
Among multiple genes aberrantly activated in cancers, invariably, there is a group related to the capacity of cell to self-renewal. Some of these genes are related to the normal process of development, including the establishment of a germline. This group, a part of growing family of Cancer/Testis (CT) genes, now includes the meiosis specific subunits of cohesin complex. The first reports characterizing the SMC1 and RAD21 genes, encoding subunits of cohesin, were published 20 years ago; however the exact molecular mechanics of cohesin molecular machine in vivo remains rather obscure notwithstanding ample elegant experiments. The matters are complicated by the fact that the evolution of cohesin function, which is served by just two basic types of protein complexes in budding yeast, took an explosive turn in Metazoa. The recent characterization of a new set of genes encoding cohesin subunits specific for meiosis in vertebrates adds several levels of complexity to the task of structure-function analysis of specific cohesin pathways, even more so in relation to their aberrant functionality in cancers. These three proteins, SMC1β, RAD21L and STAG3 are likely involved in a specific function in the first meiotic prophase, genetic recombination, and segregation of homologues. However, at present, it is rather challenging to pinpoint the molecular role of these proteins, particularly in synaptonemal complex or centromere function, due to the multiplicity of different cohesins in meiosis. The roles of these proteins in cancer cell physiology, upon their aberrant activation in tumors, also remain to be elucidated. Nevertheless, as the existence of Cancer/Testis cohesin complexes in tumor cells appears to be all but certain, this brings a promise of a new target for cancer therapy and/or diagnostics.
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Affiliation(s)
- Alexander Strunnikov
- Guangzhou Institutes of Biomedicine and Health, Molecular Epigenetics Laboratory, 190 Kai Yuan Avenue, Science Park, Guangzhou, 510530 China
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17
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Max is a repressor of germ cell-related gene expression in mouse embryonic stem cells. Nat Commun 2013; 4:1754. [DOI: 10.1038/ncomms2780] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 03/20/2013] [Indexed: 12/23/2022] Open
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18
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Implication of DNA demethylation and bivalent histone modification for selective gene regulation in mouse primordial germ cells. PLoS One 2012; 7:e46036. [PMID: 23029374 PMCID: PMC3461056 DOI: 10.1371/journal.pone.0046036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/28/2012] [Indexed: 01/15/2023] Open
Abstract
Primordial germ cells (PGCs) sequentially induce specific genes required for their development. We focused on epigenetic changes that regulate PGC-specific gene expression. mil-1, Blimp1, and Stella are preferentially expressed in PGCs, and their expression is upregulated during PGC differentiation. Here, we first determined DNA methylation status of mil-1, Blimp1, and Stella regulatory regions in epiblast and in PGCs, and found that they were hypomethylated in differentiating PGCs after E9.0, in which those genes were highly expressed. We used siRNA to inhibit a maintenance DNA methyltransferase, Dnmt1, in embryonic stem (ES) cells and found that the flanking regions of all three genes became hypomethylated and that expression of each gene increased 1.5- to 3-fold. In addition, we also found 1.5- to 5-fold increase of the PGC genes in the PGCLCs (PGC-like cells) induced form ES cells by knockdown of Dnmt1. We also obtained evidence showing that methylation of the regulatory region of mil-1 resulted in 2.5-fold decrease in expression in a reporter assay. Together, these results suggested that DNA demethylation does not play a major role on initial activation of the PGC genes in the nascent PGCs but contributed to enhancement of their expression in PGCs after E9.0. However, we also found that repression of representative somatic genes, Hoxa1 and Hoxb1, and a tissue-specific gene, Gfap, in PGCs was not dependent on DNA methylation; their flanking regions were hypomethylated, but their expression was not observed in PGCs at E13.5. Their promoter regions showed the bivalent histone modification in PGCs, that may be involved in repression of their expression. Our results indicated that epigenetic status of PGC genes and of somatic genes in PGCs were distinct, and suggested contribution of epigenetic mechanisms in regulation of the expression of a specific gene set in PGCs.
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19
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Qin J, Whyte WA, Anderssen E, Apostolou E, Chen HH, Akbarian S, Bronson RT, Hochedlinger K, Ramaswamy S, Young RA, Hock H. The polycomb group protein L3mbtl2 assembles an atypical PRC1-family complex that is essential in pluripotent stem cells and early development. Cell Stem Cell 2012; 11:319-32. [PMID: 22770845 DOI: 10.1016/j.stem.2012.06.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 05/18/2012] [Accepted: 06/18/2012] [Indexed: 01/10/2023]
Abstract
L3mbtl2 has been implicated in transcriptional repression and chromatin compaction but its biological function has not been defined. Here we show that disruption of L3mbtl2 results in embryonic lethality with failure of gastrulation. This correlates with compromised proliferation and abnormal differentiation of L3mbtl2(-/-) embryonic stem (ES) cells. L3mbtl2 regulates genes by recruiting a Polycomb Repressive Complex1 (PRC1)-related complex, resembling the previously described E2F6-complex, and including G9A, Hdac1, and Ring1b. The presence of L3mbtl2 at target genes is associated with H3K9 dimethylation, low histone acetylation, and H2AK119 ubiquitination, but the latter is neither dependent on L3mbtl2 nor sufficient for repression. Genome-wide studies revealed that the L3mbtl2-dependent complex predominantly regulates genes not bound by canonical PRC1 and PRC2. However, some developmental regulators are repressed by the combined activity of all three complexes. Together, we have uncovered a highly selective, essential role for an atypical PRC1-family complex in ES cells and early development.
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Affiliation(s)
- Jinzhong Qin
- Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA
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20
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L3MBTL2 protein acts in concert with PcG protein-mediated monoubiquitination of H2A to establish a repressive chromatin structure. Mol Cell 2011; 42:438-50. [PMID: 21596310 DOI: 10.1016/j.molcel.2011.04.004] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 02/01/2011] [Accepted: 03/31/2011] [Indexed: 01/15/2023]
Abstract
We have identified human MBT domain-containing protein L3MBTL2 as an integral component of a protein complex that we termed Polycomb repressive complex 1 (PRC1)-like 4 (PRC1L4), given the copresence of PcG proteins RING1, RING2, and PCGF6/MBLR. PRC1L4 also contained E2F6 and CBX3/HP1γ, known to function in transcriptional repression. PRC1L4-mediated repression necessitated L3MBTL2 that compacted chromatin in a histone modification-independent manner. Genome-wide location analyses identified several hundred genes simultaneously bound by L3MBTL2 and E2F6, preferentially around transcriptional start sites that exhibited little overlap with those targeted by other E2Fs or by L3MBTL1, another MBT domain-containing protein that interacts with RB1. L3MBTL2-specific RNAi resulted in increased expression of target genes that exhibited a significant reduction in H2A lysine 119 monoubiquitination. Our findings highlight a PcG/MBT collaboration that attains repressive chromatin without entailing histone lysine methylation marks.
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21
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Stielow B, Krüger I, Diezko R, Finkernagel F, Gillemans N, Kong-a-San J, Philipsen S, Suske G. Epigenetic silencing of spermatocyte-specific and neuronal genes by SUMO modification of the transcription factor Sp3. PLoS Genet 2010; 6:e1001203. [PMID: 21085687 PMCID: PMC2978682 DOI: 10.1371/journal.pgen.1001203] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 10/11/2010] [Indexed: 11/18/2022] Open
Abstract
SUMO modification of transcription factors is linked to repression of transcription. The physiological significance of SUMO attachment to a particular transcriptional regulator, however, is largely unknown. We have employed the ubiquitously expressed murine transcription factor Sp3 to analyze the role of SUMOylation in vivo. We generated mice and mouse embryonic fibroblasts (MEFs) carrying a subtle point mutation in the SUMO attachment sequence of Sp3 (IKEE553D mutation). The E553D mutation impedes SUMOylation of Sp3 at K551in vivo, without affecting Sp3 protein levels. Expression profiling revealed that spermatocyte-specific genes, such as Dmc1 and Dnahc8, and neuronal genes, including Paqr6, Rims3, and Robo3, are de-repressed in non-testicular and extra-neuronal mouse tissues and in mouse embryonic fibroblasts expressing the SUMOylation-deficient Sp3E553D mutant protein. Chromatin immunoprecipitation experiments show that transcriptional de-repression of these genes is accompanied by the loss of repressive heterochromatic marks such as H3K9 and H4K20 tri-methylation and impaired recruitment of repressive chromatin-modifying enzymes. Finally, analysis of the DNA methylation state of the Dmc1, Paqr6, and Rims3 promoters by bisulfite sequencing revealed that these genes are highly methylated in Sp3wt MEFs but are unmethylated in Sp3E553D MEFs linking SUMOylation of Sp3 to tissue-specific CpG methylation. Our results establish SUMO conjugation to Sp3 as a molecular beacon for the assembly of repression machineries to maintain tissue-specific transcriptional gene silencing. Cell type–specific gene expression patterns are largely regulated by positively or negatively acting transcription factors binding to promoter and enhancer elements. The ubiquitous transcription factor Sp3 represents a paradigm for a dual function transcription factor as it can activate and repress transcription. The repression function of Sp3 is mediated by attachment of a small protein designated SUMO to a single lysine residue. SUMOylation of Sp3 thus acts as a molecular switch that determines whether Sp3 acts as an activator or repressor. In this study, we have generated mice with a subtle mutation in the SUMO attachment site of Sp3. We found that several spermatocyte- and brain-specific genes that are silenced in non-testicular and extra-neuronal tissues of wild-type animals become aberrantly de-repressed in mice in which the SUMO attachment site of Sp3 is mutated. De-repression of these genes is accompanied with dramatic epigenetic changes including the loss of repressive histone methylation marks and, most significantly, loss of DNA methylation. Our findings suggest that SUMO modification of a transcription factor can act as a molecular beacon for the assembly of repression machineries to maintain tissue-specific transcriptional gene silencing in vivo.
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Affiliation(s)
- Bastian Stielow
- Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Marburg, Germany
| | - Imme Krüger
- Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Marburg, Germany
| | - Rolf Diezko
- Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Marburg, Germany
| | - Florian Finkernagel
- Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Marburg, Germany
| | - Nynke Gillemans
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | - John Kong-a-San
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | - Sjaak Philipsen
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | - Guntram Suske
- Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Marburg, Germany
- * E-mail:
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22
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Velasco G, Hubé F, Rollin J, Neuillet D, Philippe C, Bouzinba-Segard H, Galvani A, Viegas-Péquignot E, Francastel C. Dnmt3b recruitment through E2F6 transcriptional repressor mediates germ-line gene silencing in murine somatic tissues. Proc Natl Acad Sci U S A 2010; 107:9281-6. [PMID: 20439742 PMCID: PMC2889045 DOI: 10.1073/pnas.1000473107] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Methylation of cytosine residues within the CpG dinucleotide in mammalian cells is an important mediator of gene expression, genome stability, X-chromosome inactivation, genomic imprinting, chromatin structure, and embryonic development. The majority of CpG sites in mammalian cells is methylated in a nonrandom fashion, raising the question of how DNA methylation is distributed along the genome. Here, we focused on the functions of DNA methyltransferase-3b (Dnmt3b), of which deregulated activity is linked to several human pathologies. We generated Dnmt3b hypomorphic mutant mice with reduced catalytic activity, which first revealed a deregulation of Hox genes expression, consistent with the observed homeotic transformations of the posterior axis. In addition, analysis of deregulated expression programs in Dnmt3b mutant embryos, using DNA microarrays, highlighted illegitimate activation of several germ-line genes in somatic tissues that appeared to be linked directly to their hypomethylation in mutant embryos. We provide evidence that these genes are direct targets of Dnmt3b. Moreover, the recruitment of Dnmt3b to their proximal promoter is dependant on the binding of the E2F6 transcriptional repressor, which emerges as a common hallmark in the promoters of genes found to be up-regulated as a consequence of impaired Dnmt3b activity. Therefore, our results unraveled a coordinated regulation of genes involved in meiosis, through E2F6-dependant methylation and transcriptional silencing in somatic tissues.
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Affiliation(s)
- Guillaume Velasco
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
| | - Florent Hubé
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
| | - Jérôme Rollin
- Commissariat à l'Energie Atomique, Direction des Science du Vivant, Institut de Radiobiologie Cellulaire et Moleculaire, Laboratoire d'Exploration Fonctionnelle des Génomes, 91000 Evry, France
- Department of Hematology-Hemostasis, Trousseau Hospital and François Rabelais University, 37000 Tours, France
| | - Damien Neuillet
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
| | - Cathy Philippe
- Commissariat à l'Energie Atomique, Direction des Science du Vivant, Institut de Radiobiologie Cellulaire et Moleculaire, Laboratoire d'Exploration Fonctionnelle des Génomes, 91000 Evry, France
| | - Haniaa Bouzinba-Segard
- Institut Cochin, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université Paris Descartes, 75014 Paris, France; and
| | - Angélique Galvani
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
| | - Evani Viegas-Péquignot
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
| | - Claire Francastel
- Centre National de la Recherche Scientifique, University Paris Diderot, 75013 Paris, France
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23
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Costello I, Biondi CA, Taylor JM, Bikoff EK, Robertson EJ. Smad4-dependent pathways control basement membrane deposition and endodermal cell migration at early stages of mouse development. BMC DEVELOPMENTAL BIOLOGY 2009; 9:54. [PMID: 19849841 PMCID: PMC2773778 DOI: 10.1186/1471-213x-9-54] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 10/22/2009] [Indexed: 01/04/2023]
Abstract
Background Smad4 mutant embryos arrest shortly after implantation and display a characteristic shortened proximodistal axis, a significantly reduced epiblast, as well as a thickened visceral endoderm layer. Conditional rescue experiments demonstrate that bypassing the primary requirement for Smad4 in the extra-embryonic endoderm allows the epiblast to gastrulate. Smad4-independent TGF-β signals are thus sufficient to promote mesoderm formation and patterning. To further analyse essential Smad4 activities contributed by the extra-embryonic tissues, and characterise Smad4 dependent pathways in the early embryo, here we performed transcriptional profiling of Smad4 null embryonic stem (ES) cells and day 4 embryoid bodies (EBs). Results Transcripts from wild-type versus Smad4 null ES cells and day 4 EBs were analysed using Illumina arrays. In addition to several known TGF-β/BMP target genes, we identified numerous Smad4-dependent transcripts that are mis-expressed in the mutants. As expected, mesodermal cell markers were dramatically down-regulated. We also observed an increase in non-canonical potency markers (Pramel7, Tbx3, Zscan4), germ cell markers (Aire, Tuba3a, Dnmt3l) as well as early endoderm markers (Dpp4, H19, Dcn). Additionally, expression of the extracellular matrix (ECM) remodelling enzymes Mmp14 and Mmp9 was decreased in Smad4 mutant ES and EB populations. These changes, in combination with increased levels of laminin alpha1, cause excessive basement membrane deposition. Similarly, in the context of the Smad4 null E6.5 embryos we observed an expanded basement membrane (BM) associated with the thickened endoderm layer. Conclusion Smad4 functional loss results in a dramatic shift in gene expression patterns and in the endodermal cell lineage causes an excess deposition of, or an inability to breakdown and remodel, the underlying BM layer. These structural abnormalities probably disrupt reciprocal signalling between the epiblast and overlying visceral endoderm required for gastrulation.
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Affiliation(s)
- Ita Costello
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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24
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Adelfalk C, Janschek J, Revenkova E, Blei C, Liebe B, Göb E, Alsheimer M, Benavente R, de Boer E, Novak I, Höög C, Scherthan H, Jessberger R. Cohesin SMC1beta protects telomeres in meiocytes. J Cell Biol 2009; 187:185-99. [PMID: 19841137 PMCID: PMC2768837 DOI: 10.1083/jcb.200808016] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 09/17/2009] [Indexed: 12/29/2022] Open
Abstract
Meiosis-specific mammalian cohesin SMC1beta is required for complete sister chromatid cohesion and proper axes/loop structure of axial elements (AEs) and synaptonemal complexes (SCs). During prophase I, telomeres attach to the nuclear envelope (NE), but in Smc1beta(-/-) meiocytes, one fifth of their telomeres fail to attach. This study reveals that SMC1beta serves a specific role at telomeres, which is independent of its role in determining AE/SC length and loop extension. SMC1beta is necessary to prevent telomere shortening, and SMC3, present in all known cohesin complexes, properly localizes to telomeres only if SMC1beta is present. Very prominently, telomeres in Smc1beta(-/-) spermatocytes and oocytes loose their structural integrity and suffer a range of abnormalities. These include disconnection from SCs and formation of large telomeric protein-DNA extensions, extended telomere bridges between SCs, ring-like chromosomes, intrachromosomal telomeric repeats, and a reduction of SUN1 foci in the NE. We suggest that a telomere structure protected from DNA rearrangements depends on SMC1beta.
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Affiliation(s)
- Caroline Adelfalk
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Johannes Janschek
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Ekaterina Revenkova
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Cornelia Blei
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Bodo Liebe
- Max Planck Institute of Molecular Genetics, D-14195 Berlin, Germany
| | - Eva Göb
- Department of Cell and Developmental Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Manfred Alsheimer
- Department of Cell and Developmental Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Ricardo Benavente
- Department of Cell and Developmental Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Esther de Boer
- Memorial Sloan-Kettering Cancer Center, New York, NY 10044
| | - Ivana Novak
- Department of Cell and Molecular Biology, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Christer Höög
- Department of Cell and Molecular Biology, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Harry Scherthan
- Max Planck Institute of Molecular Genetics, D-14195 Berlin, Germany
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
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25
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Kehoe SM, Oka M, Hankowski KE, Reichert N, Garcia S, McCarrey JR, Gaubatz S, Terada N. A conserved E2F6-binding element in murine meiosis-specific gene promoters. Biol Reprod 2008; 79:921-30. [PMID: 18667754 DOI: 10.1095/biolreprod.108.067645] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
During gametogenesis, germ cells must undergo meiosis in order to become viable haploid gametes. Successful completion of this process is dependent upon the expression of genes whose protein products function specifically in meiosis. Failure to express these genes in meiotic cells often results in infertility, whereas aberrant expression in somatic cells may lead to mitotic catastrophe. The mechanisms responsible for regulating the timely expression of meiosis-specific genes have not been fully elucidated. Here we demonstrate that E2F6, a member of the E2F family of transcription factors, is essential for the repression of the newly identified meiosis-specific gene, Slc25a31 (also known as Ant4, Aac4), in somatic cells. This discovery, along with previous studies, prompted us to investigate the role of E2F6 in the regulation of meiosis-specific genes in general. Interestingly, the core E2F6-binding element (TCCCGC) was highly conserved in the proximal promoter regions of 19 out of 24 (79.2%) meiosis-specific genes. This was significantly higher than the frequency found in the promoters of all mouse genes (15.4%). In the absence of E2F6, only a portion of these meiosis-specific genes was derepressed in somatic cells. However, endogenous E2F6 bound to the promoters of these meiosis-specific genes regardless of whether they required E2F6 for their repression in somatic cells. Further, E2F6 overexpression was capable of reducing their transcription. These findings indicate that E2F6 possesses a broad ability to bind to and regulate the meiosis-specific gene population.
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Affiliation(s)
- Sarah M Kehoe
- Department of Pathology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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26
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L'Hôte D, Serres C, Laissue P, Oulmouden A, Rogel-Gaillard C, Montagutelli X, Vaiman D. Centimorgan-range one-step mapping of fertility traits using interspecific recombinant congenic mice. Genetics 2007; 176:1907-21. [PMID: 17483418 PMCID: PMC1931527 DOI: 10.1534/genetics.107.072157] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In mammals, male fertility is a quantitative feature determined by numerous genes. Until now, several wide chromosomal regions involved in fertility have been defined by genetic mapping approaches; unfortunately, the underlying genes are very difficult to identify. Here, 53 interspecific recombinant congenic mouse strains (IRCSs) bearing 1-2% SEG/Pas (Mus spretus) genomic fragments disseminated in a C57Bl/6J (Mus domesticus) background were used to systematically analyze male fertility parameters. One of the most prominent advantages of this model is the possibility of analyzing stable phenotypes in living animals. Here, we demonstrate the possibility in one-step fine mapping for several fertility traits. Focusing on strains harboring a unique spretus fragment, we could unambiguously localize two testis and one prostate weight-regulating QTL (Ltw1, Ltw2, and Lpw1), four QTL controlling the sperm nucleus shape (Sh1, Sh2, Sh3, and Sh4), and one QTL influencing sperm survival (Dss1). In several cases, the spretus DNA fragment was small enough to propose sound candidates. For instance, Spata1, Capza, and Tuba7 are very strong candidates for influencing the shape of the sperm head. Identifying new genes implied in mammalian fertility pathways is a necessary prerequisite for clarifying their molecular grounds and for proposing diagnostic tools for masculine infertilities.
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Affiliation(s)
- David L'Hôte
- Equipe 21, Génomique et Epigénetique des Pathologies Placentaires, Unité INSERM 567/UMR CNRS 8104-Université Paris, Paris, France
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27
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Kim M, Li D, Cui Y, Mueller K, Chears WC, DeJong J. Regulatory Factor Interactions and Somatic Silencing of the Germ Cell-specific ALF Gene. J Biol Chem 2006; 281:34288-98. [PMID: 16966320 DOI: 10.1074/jbc.m607168200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Germ cell-specific genes are active in oocytes and spermatocytes but are silent in all other cell types. To understand the basis for this seemingly simple pattern of regulation, we characterized factors that recognize the promoter-proximal region of the germ cell-specific TFIIA alpha/beta-like factor (ALF) gene. Two of the protein-DNA complexes formed with liver extracts (C4 and C5) are due to the zinc finger proteins Sp1 and Sp3, respectively, whereas another complex (C6) is due to the transcription factor RFX1. Two additional complexes (C1 and C3) are due to the multivalent zinc finger protein CTCF, a factor that plays a role in gene silencing and chromatin insulation. An investigation of CTCF binding revealed a recognition site of only 17 bp that overlaps with the Sp1/Sp3 site. This site is predictive of other genomic CTCF sites and can be aligned to create a functional consensus. Studies on the activity of the ALF promoter in somatic 293 cells revealed mutations that result in increased reporter activity. In addition, RNAi-mediated down-regulation of CTCF is associated with activation of the endogenous ALF gene, and both CTCF and Sp3 repress the promoter in transient transfection assays. Overall, the results suggest a role for several factors, including the multivalent zinc finger chromatin insulator protein CTCF, in mediating somatic repression of the ALF gene. Release of such repression, perhaps in conjunction with other members of the CTCF, RFX, and Sp1 families of transcription factors, could be an important aspect of germ cell gene activation.
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Affiliation(s)
- MinJung Kim
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas 75080, USA
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28
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Maatouk DM, Kellam LD, Mann MRW, Lei H, Li E, Bartolomei MS, Resnick JL. DNA methylation is a primary mechanism for silencing postmigratory primordial germ cell genes in both germ cell and somatic cell lineages. Development 2006; 133:3411-8. [PMID: 16887828 DOI: 10.1242/dev.02500] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
DNA methylation is necessary for the silencing of endogenous retrotransposons and the maintenance of monoallelic gene expression at imprinted loci and on the X chromosome. Dynamic changes in DNA methylation occur during the initial stages of primordial germ cell development; however, all consequences of this epigenetic reprogramming are not understood. DNA demethylation in postmigratory primordial germ cells coincides with erasure of genomic imprints and reactivation of the inactive X chromosome, as well as ongoing germ cell differentiation events. To investigate a possible role for DNA methylation changes in germ cell differentiation, we have studied several marker genes that initiate expression at this time. Here, we show that the postmigratory germ cell-specific genes Mvh, Dazl and Scp3 are demethylated in germ cells, but not in somatic cells. Premature loss of genomic methylation in Dnmt1 mutant embryos leads to early expression of these genes as well as GCNA1, a widely used germ cell marker. In addition, GCNA1 is ectopically expressed by somatic cells in Dnmt1 mutants. These results provide in vivo evidence that postmigratory germ cell-specific genes are silenced by DNA methylation in both premigratory germ cells and somatic cells. This is the first example of ectopic gene activation in Dnmt1 mutant mice and suggests that dynamic changes in DNA methylation regulate tissue-specific gene expression of a set of primordial germ cell-specific genes.
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Affiliation(s)
- Danielle M Maatouk
- Department of Molecular Genetics and Microbiology, PO Box 100266, University of Florida, Gainesville, FL 32610-0266, USA
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