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Coconubo DM, Wangsiricharoen S, Pettus JR, Linos K, Pinto A, Wang WL, Kerr DA, Cloutier JM. A Subset of Thoracic SMARCA4-Deficient Undifferentiated Tumors Express GATA3. Int J Surg Pathol 2024; 32:684-691. [PMID: 37461275 DOI: 10.1177/10668969231188904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a rare and highly aggressive malignant neoplasm characterized by high-grade undifferentiated morphologic features and recurrent inactivating mutations of SMARCA4. These tumors consistently exhibit loss of SMARCA4 (BRG1) while displaying variable expression of other nonspecific markers. Recently, we encountered a SMARCA4-UT demonstrating immunoreactivity for GATA3, and we sought to characterize this phenomenon in a larger series. A total of nine SMARCA4-UTs were examined from 3 large academic institutions. The clinicopathologic and molecular characteristics were studied and GATA3 immunohistochemistry was performed. The cohort included 5 male and 4 female patients, with a median age of 54 years and a median smoking history of 37 pack-years. At initial diagnosis, mediastinal lymph node involvement was observed in 5 patients (56%) while distant metastases were present in 7 patients (78%). The median survival was 6 months. Histologically, the tumors were characterized by sheets of undifferentiated epithelioid and/or rhabdoid cells, accompanied by frequent mitotic figures and necrosis. Immunohistochemically, all tumors displayed a complete loss of BRG1 expression. Notably, 4 of 9 tumors (44%) were positive for GATA3 expression, including one tumor that exhibited strong and diffuse immunoreactivity. GATA3 expression in SMARCA4-UT may pose diagnostic challenges, requiring differentiation from other GATA3-positive tumors. This distinction is crucial for accurate prognostication and treatment decisions.
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Affiliation(s)
- Daniel Martinez Coconubo
- Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA
- Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | | | - Jason R Pettus
- Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA
- Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Konstantinos Linos
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Andre Pinto
- Department of Pathology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Wei-Lien Wang
- Department of Pathology, The University of Texas at MD Anderson Cancer Center, Houston, TX, USA
| | - Darcy A Kerr
- Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA
- Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jeffrey M Cloutier
- Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA
- Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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Cheung AHK, Wong KY, Chau SL, Xie F, Mui Z, Li GYH, Li MSC, Tong J, Ng CSH, Mok TS, Kang W, To KF. SMARCA4 deficiency and mutations are frequent in large cell lung carcinoma and are prognostically significant. Pathology 2024; 56:504-515. [PMID: 38413251 DOI: 10.1016/j.pathol.2023.12.414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 11/23/2023] [Accepted: 12/06/2023] [Indexed: 02/29/2024]
Abstract
SMARCA4 mutation has emerged as a marker of poor prognosis in lung cancer and has potential predictive value in cancer treatment, but recommendations for which patients require its investigation are lacking. We comprehensively studied SMARCA4 alterations and the clinicopathological significance in a large cohort of immunohistochemically-subtyped non-small cell lung cancer (NSCLC). A total of 1416 patients was studied for the presence of SMARCA4 deficiency by immunohistochemistry (IHC). Thereafter, comprehensive sequencing of tumours was performed for 397 of these patients to study the mutational spectrum of SWI/SNF and SMARCA4 aberrations. IHC evidence of SMARCA4 deficiency was found in 2.9% of NSCLC. Of the sequenced tumours, 38.3% showed aberration in SWI/SNF complex, and 9.3% had SMARCA4 mutations. Strikingly, SMARCA4 aberrations were much more prevalent in large cell carcinoma (LCC) than other histological tumour subtypes. SMARCA4-deficient and SMARCA4-mutated tumours accounted for 40.5% and 51.4% of all LCC, respectively. Multivariable analyses confirmed SMARCA4 mutation was an independent prognostic factor in lung cancer. The immunophenotype of a subset of these tumours frequently showed TTF1 negativity and HepPAR1 positivity. SMARCA4 mutation or its deficiency was associated with positive smoking history and poor prognosis. It also demonstrated mutual exclusion with EGFR mutation. Taken together, the high incidence of SMARCA4 aberrations in LCC may indicate its diagnostic and prognostic value. Our study established the necessity of SMARCA4 IHC in the identification of SMARCA4-aberrant tumours, and this may be of particular importance in LCC and tumours without known driver events.
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Affiliation(s)
- Alvin Ho-Kwan Cheung
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Kit-Yee Wong
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Shuk-Ling Chau
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Fuda Xie
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China; State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
| | - Zeta Mui
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Gordon Yuan-Ho Li
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Molly Siu Ching Li
- Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Joanna Tong
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Calvin Sze-Hang Ng
- Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Tony S Mok
- Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China; State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
| | - Ka-Fai To
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China; State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
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3
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Rekhtman N. All That Is Small Is Not a Small-Cell Carcinoma: Thoracic SMARCA4-Deficient Undifferentiated Tumors Masquerading as SCLC. Clin Cancer Res 2024; 30:1708-1711. [PMID: 38416596 DOI: 10.1158/1078-0432.ccr-24-0227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/08/2024] [Accepted: 02/16/2024] [Indexed: 03/01/2024]
Abstract
Small-cell lung carcinoma (SCLC) cell lines have been widely utilized as a preclinical model of this highly aggressive disease. However, since their creation decades ago, novel tumor entities have been defined that might clinicopathologically mimic SCLC, which notably includes thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Multiomic reassessment of the presumed SCLC cell lines with high YAP1 expression reveals that nearly all of these tumors represent unsuspected SMARCA4-UT. See related article by Ng et al., p. 1846.
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Mundada M, Mannan KA, Vasu D, Ahmed F, K S. Under the Microscope: A Case Report of Thoracic SMARCA4-Deficient Undifferentiated Tumor with Review of the Literature. Turk Patoloji Derg 2024; 40:128-133. [PMID: 38265099 DOI: 10.5146/tjpath.2023.12965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024] Open
Abstract
OBJECTIVE SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a highly malignant neoplasm with an undifferentiated or rhabdoid phenotype, posing a diagnostic challenge. This case report aims to create awareness about this rare neoplasm while dealing with cases presenting with undifferentiated morphology. CASE REPORT A 55-year-old gentleman with constitutional symptoms and lymphadenopathy. Imaging revealed a mass lesion in the right upper lobe of the lung. A biopsy of the cervical lymph node showed diffusely effaced architecture replaced by sheets of undifferentiated pleomorphic cells with vesicular nuclei, prominent nucleoli, eosinophilic cytoplasm, and multiple necrotic foci. An extensive immunohistochemistry (IHC) panel was applied, which showed positivity for synaptophysin, vimentin, and focal CD34 and EMA expression. Other markers like pan-cytokeratin, p40, TTF1, CD56, INSM1, calretinin, CD45, SOX10, S100, CD30, CD117, SMA, and Desmin were negative, with INI1 retained. The IHC panel excluded the morphological differentials of carcinoma, lymphoma, rhabdomyosarcoma, melanoma, and germ cell tumor. Further literature review led to the possibility of the SMARCA4-UT entity, which had a morphology and IHC profile similar to the present case. Testing for SMARCA4 (BRG-1) by IHC showed a complete loss in the tumor cells, favoring the diagnosis of Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). CONCLUSION SMARCA4-UTs are rare, highly aggressive, and poorly differentiated thoracic tumors. Recognizing them is vital as there is potential for therapeutic interventions such as immunotherapy and SMARCA4-targeted therapies, offering promising prospects for the future.
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Affiliation(s)
- Manasi Mundada
- Department of Pathology, Basavatarakam Indo American Cancer Hospital & Research Institute, HYDERABAD, INDIA
| | - Khalid Abdul Mannan
- Department of Pathology, Basavatarakam Indo American Cancer Hospital & Research Institute, HYDERABAD, INDIA
| | - Divya Vasu
- Department of Pathology, Basavatarakam Indo American Cancer Hospital & Research Institute, HYDERABAD, INDIA
| | - Faiq Ahmed
- Department of Pathology, Basavatarakam Indo American Cancer Hospital & Research Institute, HYDERABAD, INDIA
| | - Suseela K
- Department of Pathology, Basavatarakam Indo American Cancer Hospital & Research Institute, HYDERABAD, INDIA
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Gantzer J, Davidson G, Vokshi B, Weingertner N, Bougoüin A, Moreira M, Lindner V, Lacroix G, Mascaux C, Chenard MP, Bertucci F, Davidson I, Kurtz JE, Sautès-Fridman C, Fridman WH, Malouf GG. OUP accepted manuscript. Oncologist 2022; 27:501-511. [PMID: 35278076 PMCID: PMC9177113 DOI: 10.1093/oncolo/oyac040] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 01/14/2022] [Indexed: 11/14/2022] Open
Abstract
Background Thoracic SMARCA4-deficient undifferentiated tumors (SMARCA4-UT) are aggressive neoplasms. Data linking BAF alterations with tumor microenvironment (TME) and efficacy of immune checkpoint inhibitors (ICI) are contradictory. The TME of SMARCA4-UT and their response to ICI are unknown. Materials and Methods Patients diagnosed with SMARCA4-UT in our institution were included. Immunostainings for tertiary lymphoid structures (TLS), immune cell markers, and checkpoints were assessed. Validation was performed using an independent transcriptome dataset including SMARCA4-UT, non–small cell lung cancers (NSCLC) with/without SMARCA4 mutations, and unclassified thoracic sarcomas (UTS). CXCL9 and PD-L1 expressions were assessed in NSCLC and thoracic fibroblast cell lines, with/without SMARCA4 knockdown, treated with/without interferon gamma. Results Nine patients were identified. All samples but one showed no TLS, consistent with an immune desert TME phenotype. Four patients received ICI as part of their treatment, but the only one who responded, had a tumor with a TLS and immune-rich TME. Unsupervised clustering of the validation cohort using immune cell scores identified 2 clusters associated with cell ontogeny and immunity (cluster 1 enriched for NSCLC independently of SMARCA4 status (n = 9/10; P = .001); cluster 2 enriched for SMARCA4-UT (n = 11/12; P = .005) and UTS (n = 5/5; P = .0005). SMARCA4 loss-of-function experiments revealed interferon-induced upregulation of CXCL9 and PD-L1 expression in the NSCLC cell line with no effect on the thoracic fibroblast cell line. Conclusion SMARCA4-UT mainly have an immune desert TME with limited efficacy to ICI. TME of SMARCA4-driven tumors varies according to the cell of origin questioning the interplay between BAF alterations, cell ontogeny and immunity.
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Affiliation(s)
- Justine Gantzer
- Corresponding author: Justine Gantzer, Department of Medical Oncology, Strasbourg-Europe Cancer Institute (ICANS), 17 rue Albert Calmette, 67033 Strasbourg, France. Tel: +33 3 68 76 72 25;
| | - Guillaume Davidson
- Department of Cancer and Functional Genomics, INSERM UMR_S1258, Institute of Genetics and of Molecular and Cellular Biology, Illkirch, France
| | - Bujamin Vokshi
- Department of Cancer and Functional Genomics, INSERM UMR_S1258, Institute of Genetics and of Molecular and Cellular Biology, Illkirch, France
| | - Noëlle Weingertner
- Fédération de Médecine Translationnelle (FMTS), Strasbourg, France
- Department of Pathology, University Hospital, Strasbourg, France
| | - Antoine Bougoüin
- Centre de recherche des Cordeliers, INSERM, Université de Paris, Sorbonne Université, Team 13- Complement, Inflammation and Cancer, Équipe labellisée Ligue contre le cancer, Paris, France
| | - Marco Moreira
- Centre de recherche des Cordeliers, INSERM, Université de Paris, Sorbonne Université, Team 13- Complement, Inflammation and Cancer, Équipe labellisée Ligue contre le cancer, Paris, France
| | - Véronique Lindner
- Fédération de Médecine Translationnelle (FMTS), Strasbourg, France
- Department of Pathology, University Hospital, Strasbourg, France
| | - Guillaume Lacroix
- Centre de recherche des Cordeliers, INSERM, Université de Paris, Sorbonne Université, Team 13- Complement, Inflammation and Cancer, Équipe labellisée Ligue contre le cancer, Paris, France
| | - Céline Mascaux
- Department of Pneumology, University Hospital, Strasbourg, France
- University of Strasbourg, Inserm UMR_S 1113, IRFAC, Laboratory Streinth (STress REsponse and INnovative THerapy against cancer), Strasbourg, France
| | - Marie-Pierre Chenard
- Fédération de Médecine Translationnelle (FMTS), Strasbourg, France
- Department of Pathology, University Hospital, Strasbourg, France
| | - François Bertucci
- Department of Medical Oncology, Cancer Research Center of Marseille (CRCM), INSERM U1068, CNRS UMR7258, Institut Paoli Calmettes, Aix-Marseille University, Marseille, France
| | - Irwin Davidson
- Department of Cancer and Functional Genomics, INSERM UMR_S1258, Institute of Genetics and of Molecular and Cellular Biology, Illkirch, France
| | - Jean-Emmanuel Kurtz
- Department of Medical Oncology, Strasbourg-Europe Cancer Institute (ICANS), Strasbourg, France
- Fédération de Médecine Translationnelle (FMTS), Strasbourg, France
| | - Catherine Sautès-Fridman
- Centre de recherche des Cordeliers, INSERM, Université de Paris, Sorbonne Université, Team 13- Complement, Inflammation and Cancer, Équipe labellisée Ligue contre le cancer, Paris, France
| | | | - Gabriel G Malouf
- Gabriel G. Malouf, Department of Medical Oncology, Strasbourg-Europe Cancer Institute (ICANS), 17 rue Albert Calmette, 67033 Strasbourg, France. Tel: +33 3 68 76 72 17;
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Kasajima A, Konukiewitz B, Schlitter AM, Weichert W, Bräsen JH, Agaimy A, Klöppel G. Mesenchymal/non-epithelial mimickers of neuroendocrine neoplasms with a focus on fusion gene-associated and SWI/SNF-deficient tumors. Virchows Arch 2021; 479:1209-1219. [PMID: 34350470 PMCID: PMC8724147 DOI: 10.1007/s00428-021-03156-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 12/24/2022]
Abstract
Mimickers of neuroendocrine neoplasms (NEN) include a number of important pitfall tumors. Here, we describe our experience with mesenchymal mimics of NENs to illustrate their spectrum and draw the attention particularly to a group of mesenchymal/non-epithelial neoplasms (MN) that combine epithelioid histology with neuroendocrine (NE-) features and peculiar genetic abnormalities. In a consultation series of 4498 cases collected between 2009 and 2021, 2099 neoplasms expressing synaptophysin and/or chromograninA were reviewed and analyzed. A total of 364 (18%) were diagnosed as non-NENs, while the remaining tumors were NEN. The group of mesenchymal/non-epithelial neoplasms with NE-features (MN-NE) included 31/364 (8%) cases. These mostly malignant neoplasms showed an epithelioid morphology. While all but one tumor expressed synaptophysin, mostly patchy, only 10/29 (34%) co-expressed chromograninA. A total of 13/31 (42%) of the MN-NE showed EWSR1-related gene fusions (6 Ewing sarcomas, 5 clear cell sarcomas, and 1 desmoplastic small round cell tumor, 1 neoplasm with FUS-CREM gene fusion) and 7 (23%) were SWI/SNF (SMARCB1 or SMARCA4)-deficient neoplasms. The remaining MN-NE included synovial sarcoma, sclerosing epithelioid mesenchymal neoplasm, melanoma, alveolar soft part sarcoma, solitary fibrous tumor, and chordoma. A total of 27/31 MN-NE were from the last 8 years, and 6 of them were located in the pancreas. Eleven MN-NE were initially diagnosed as neuroendocrine carcinomas (NECs). MN-NE with epithelioid features play an increasing role as mimickers of NECs. They mostly belong to tumors with gene fusions involving the EWSR1 gene, or with SWI/SNF complex deficiency. Synaptophysin expression is mostly patchy and chromograninA expression is infrequent in MN-NE of this series and data extracted from literature.
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Affiliation(s)
- Atsuko Kasajima
- Department of Pathology, Technical University Munich, Trogerstr. 18, 81675, Munich, Germany.
- The German Cancer Consortium (DKTK), Heidelberg, Germany.
| | - Björn Konukiewitz
- Department of Pathology, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Anna Melissa Schlitter
- Department of Pathology, Technical University Munich, Trogerstr. 18, 81675, Munich, Germany
- The German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Wilko Weichert
- Department of Pathology, Technical University Munich, Trogerstr. 18, 81675, Munich, Germany
- The German Cancer Consortium (DKTK), Heidelberg, Germany
| | | | - Abbas Agaimy
- Institute of Pathology, Friedrich-Alexander-University, Erlangen-Nürnberg, University Hospital, Erlangen, Germany
| | - Günter Klöppel
- Department of Pathology, Technical University Munich, Trogerstr. 18, 81675, Munich, Germany
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Subramanian GN, Lavin M, Homer HA. Premature ovarian ageing following heterozygous loss of Senataxin. Mol Hum Reprod 2021; 27:gaaa080. [PMID: 33337500 DOI: 10.1093/molehr/gaaa080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/09/2020] [Indexed: 12/21/2022] Open
Abstract
Premature loss of ovarian activity before 40 years of age is known as primary ovarian insufficiency (POI) and occurs in ∼1% of women. A more subtle decline in ovarian activity, known as premature ovarian ageing (POA), occurs in ∼10% of women. Despite the high prevalence of POA, very little is known regarding its genetic causation. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage. Homozygous mutation of SETX leads to the neurodegenerative disorder, ataxia oculomotor apraxia type 2 (AOA2). There have been reports of POI in AOA2 females suggesting a link between SETX and ovarian ageing. Here, we studied female mice lacking either one (Setx+/-) or both (Setx-/-) copies of SETX over a 12- to 14-month period. We find that DNA damage is increased in oocytes from 8-month-old Setx+/- and Setx-/- females compared with Setx+/+ oocytes leading to a marked reduction in all classes of ovarian follicles at least 4 months earlier than typically occurs in female mice. Furthermore, during a 12-month long mating trial, Setx+/- and Setx-/- females produced significantly fewer pups than Setx+/+ females from 7 months of age onwards. These data show that SETX is critical for preventing POA in mice, likely by preserving DNA integrity in oocytes. Intriguingly, heterozygous Setx loss causes an equally severe impact on ovarian ageing as homozygous Setx loss. Because heterozygous SETX disruption is less likely to produce systemic effects, SETX compromise could underpin some cases of insidious POA.
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Affiliation(s)
- G N Subramanian
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - M Lavin
- Cancer and Neuroscience Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - H A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
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8
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Karnezis AN, Chen SY, Chow C, Yang W, Hendricks WPD, Ramos P, Briones N, Mes-Masson AM, Bosse T, Gilks CB, Trent JM, Weissman B, Huntsman DG, Wang Y. Re-assigning the histologic identities of COV434 and TOV-112D ovarian cancer cell lines. Gynecol Oncol 2021; 160:568-578. [PMID: 33328126 PMCID: PMC10039450 DOI: 10.1016/j.ygyno.2020.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 12/05/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The development of effective cancer treatments depends on the availability of cell lines that faithfully recapitulate the cancer in question. This study definitively re-assigns the histologic identities of two ovarian cancer cell lines, COV434 (originally described as a granulosa cell tumour) and TOV-112D (originally described as grade 3 endometrioid carcinoma), both of which were recently suggested to represent small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), based on their shared gene expression profiles and sensitivity to EZH2 inhibitors. METHODS For COV434 and TOV-112D, we re-reviewed the original pathology slides and obtained clinical follow-up on the patients, when available, and performed immunohistochemistry for SMARCA4, SMARCA2 and additional diagnostic markers on the original formalin-fixed, paraffin-embedded (FFPE) clinical material, when available. For COV434, we further performed whole exome sequencing and validated SMARCA4 mutations by Sanger sequencing. We studied the growth of the cell lines at baseline and upon re-expression of SMARCA4 in vitro for both cell lines and evaluated the serum calcium levels in vivo upon injection into immunodeficient mice for COV434 cells. RESULTS The available morphological, immunohistochemical, genetic, and clinical features indicate COV434 is derived from SCCOHT, and TOV-112D is a dedifferentiated carcinoma. Transplantation of COV434 into mice leads to increased serum calcium level. Re-expression of SMARCA4 in either COV434 and TOV-112D cells suppressed their growth dramatically. CONCLUSIONS COV434 represents a bona fide SCCOHT cell line. TOV-112D is a dedifferentiated ovarian carcinoma cell line.
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MESH Headings
- Animals
- Carcinoma, Ovarian Epithelial/diagnosis
- Carcinoma, Ovarian Epithelial/drug therapy
- Carcinoma, Ovarian Epithelial/genetics
- Carcinoma, Ovarian Epithelial/pathology
- Carcinoma, Small Cell/diagnosis
- Carcinoma, Small Cell/drug therapy
- Carcinoma, Small Cell/genetics
- Carcinoma, Small Cell/pathology
- Cell Dedifferentiation/genetics
- Cell Line, Tumor/drug effects
- Cell Line, Tumor/pathology
- DNA Helicases/analysis
- DNA Helicases/deficiency
- DNA Helicases/genetics
- Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitors
- Female
- Gene Expression Profiling
- Humans
- Mice
- Nuclear Proteins/analysis
- Nuclear Proteins/deficiency
- Nuclear Proteins/genetics
- Ovarian Neoplasms/diagnosis
- Ovarian Neoplasms/drug therapy
- Ovarian Neoplasms/genetics
- Ovarian Neoplasms/pathology
- Transcription Factors/analysis
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Exome Sequencing
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Anthony N Karnezis
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Pathology and Laboratory Medicine, University of California, Davis Medical Center, Sacramento, CA, USA
| | - Shary Yuting Chen
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Molecular Oncology, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Christine Chow
- Genetic Pathology Evaluation Centre, Vancouver General Hospital and University of British Columbia, Vancouver, BC, Canada
| | - Winnie Yang
- Department of Molecular Oncology, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - William P D Hendricks
- Division of Integrated Cancer Genomics, Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - Pilar Ramos
- Division of Integrated Cancer Genomics, Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - Natalia Briones
- Division of Integrated Cancer Genomics, Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - Anne-Marie Mes-Masson
- Centre de recherche du Centre hospitalier de l'Université de Montréal and Institut du cancer de Montréal, Montreal, QC, Canada; Department of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Tjalling Bosse
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - C Blake Gilks
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jeffrey M Trent
- Division of Integrated Cancer Genomics, Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - Bernard Weissman
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - David G Huntsman
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Molecular Oncology, British Columbia Cancer Research Institute, Vancouver, BC, Canada; Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada.
| | - Yemin Wang
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Molecular Oncology, British Columbia Cancer Research Institute, Vancouver, BC, Canada.
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Gong J, Mou T, Wu H, Wu Z. Brg1 regulates murine liver regeneration by targeting miR-187-5p dependent on Hippo signalling pathway. J Cell Mol Med 2020; 24:11592-11602. [PMID: 32845093 PMCID: PMC7576256 DOI: 10.1111/jcmm.15776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022] Open
Abstract
Brg1 and Hippo signalling pathway are abnormally expressed in many malignant tumours, especially in Hepatocellular carcinoma, but their role in liver regeneration (LR) is unknown. In our research, we investigated the role of Brg1 and Hippo signalling pathway in hepatocyte proliferation and LR. Following 2/3 partial hepatectomy (PH) in liver-specific Brg1 deleted mice (Brg1-/-) (KO) mice and sex-matched wild-type (WT), depletion of Brg1 in mouse embryos caused liver cell growth disorders and significantly decreased expression of miR-187-5p. We identified LATS1 as a target gene of miR-187-5p and the introduction of miR-187-5p decrease the expression of LATS1 and inactivated the Hippo signalling pathway, which facilitated the expression of cell cycle-related proteins, and rescues the inhibitory effect of Brg1 in LR. Taken together, our findings suggested that deletion of Brg1 inhibits hepatocyte proliferation and LR by targeting miR-187-5p dependent on Hippo signalling pathway.
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Affiliation(s)
- Junhua Gong
- Department of Hepatobiliary SurgeryThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Tong Mou
- Department of Hepatobiliary SurgeryThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Hao Wu
- Department of Hepatobiliary SurgeryThe Second Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Zhongjun Wu
- Department of Hepatobiliary SurgeryThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
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10
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Gupta M, Concepcion CP, Fahey CG, Keshishian H, Bhutkar A, Brainson CF, Sanchez-Rivera FJ, Pessina P, Kim JY, Simoneau A, Paschini M, Beytagh MC, Stanclift CR, Schenone M, Mani DR, Li C, Oh A, Li F, Hu H, Karatza A, Bronson RT, Shaw AT, Hata AN, Wong KK, Zou L, Carr SA, Jacks T, Kim CF. BRG1 Loss Predisposes Lung Cancers to Replicative Stress and ATR Dependency. Cancer Res 2020; 80:3841-3854. [PMID: 32690724 PMCID: PMC7501156 DOI: 10.1158/0008-5472.can-20-1744] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/15/2020] [Accepted: 07/15/2020] [Indexed: 12/22/2022]
Abstract
Inactivation of SMARCA4/BRG1, the core ATPase subunit of mammalian SWI/SNF complexes, occurs at very high frequencies in non-small cell lung cancers (NSCLC). There are no targeted therapies for this subset of lung cancers, nor is it known how mutations in BRG1 contribute to lung cancer progression. Using a combination of gain- and loss-of-function approaches, we demonstrate that deletion of BRG1 in lung cancer leads to activation of replication stress responses. Single-molecule assessment of replication fork dynamics in BRG1-deficient cells revealed increased origin firing mediated by the prelicensing protein, CDC6. Quantitative mass spectrometry and coimmunoprecipitation assays showed that BRG1-containing SWI/SNF complexes interact with RPA complexes. Finally, BRG1-deficient lung cancers were sensitive to pharmacologic inhibition of ATR. These findings provide novel mechanistic insight into BRG1-mutant lung cancers and suggest that their dependency on ATR can be leveraged therapeutically and potentially expanded to BRG1-mutant cancers in other tissues. SIGNIFICANCE: These findings indicate that inhibition of ATR is a promising therapy for the 10% of non-small cell lung cancer patients harboring mutations in SMARCA4/BRG1. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/18/3841/F1.large.jpg.
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Affiliation(s)
- Manav Gupta
- Stem Cell Program, Division of Hematology/Oncology and Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
- Biological and Biomedical Sciences PhD Program, Harvard University, Boston, Massachusetts
| | - Carla P Concepcion
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Caroline G Fahey
- Stem Cell Program, Division of Hematology/Oncology and Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
| | | | - Arjun Bhutkar
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Christine F Brainson
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, Kentucky
| | | | - Patrizia Pessina
- Stem Cell Program, Division of Hematology/Oncology and Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
| | - Jonathan Y Kim
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Antoine Simoneau
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts
| | - Margherita Paschini
- Stem Cell Program, Division of Hematology/Oncology and Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
| | - Mary C Beytagh
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | | | - Monica Schenone
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - D R Mani
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Chendi Li
- Massachusetts General Hospital Cancer Center and Department of Medicine, Massachusetts General Hospital Harvard Medical School, Boston, Massachusetts
| | - Audris Oh
- Massachusetts General Hospital Cancer Center and Department of Medicine, Massachusetts General Hospital Harvard Medical School, Boston, Massachusetts
| | - Fei Li
- Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, NYU Langone Health, New York, New York
| | - Hai Hu
- Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, NYU Langone Health, New York, New York
| | - Angeliki Karatza
- Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, NYU Langone Health, New York, New York
| | - Roderick T Bronson
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts
| | - Alice T Shaw
- Massachusetts General Hospital Cancer Center and Department of Medicine, Massachusetts General Hospital Harvard Medical School, Boston, Massachusetts
| | - Aaron N Hata
- Massachusetts General Hospital Cancer Center and Department of Medicine, Massachusetts General Hospital Harvard Medical School, Boston, Massachusetts
| | - Kwok-Kin Wong
- Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, NYU Langone Health, New York, New York
| | - Lee Zou
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts
| | - Steven A Carr
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Tyler Jacks
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Howard Hughes Medical Institute, Cambridge, Massachusetts
| | - Carla F Kim
- Stem Cell Program, Division of Hematology/Oncology and Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts.
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
- Harvard Stem Cell Institute, Cambridge, Massachusetts
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11
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Baumann C, Ma W, Wang X, Kandasamy MK, Viveiros MM, De La Fuente R. Helicase LSH/Hells regulates kinetochore function, histone H3/Thr3 phosphorylation and centromere transcription during oocyte meiosis. Nat Commun 2020; 11:4486. [PMID: 32900989 PMCID: PMC7478982 DOI: 10.1038/s41467-020-18009-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/23/2020] [Indexed: 12/31/2022] Open
Abstract
Centromeres are epigenetically determined nuclear domains strictly required for chromosome segregation and genome stability. However, the mechanisms regulating centromere and kinetochore chromatin modifications are not known. Here, we demonstrate that LSH is enriched at meiotic kinetochores and its targeted deletion induces centromere instability and abnormal chromosome segregation. Superresolution chromatin analysis resolves LSH at the inner centromere and kinetochores during oocyte meiosis. LSH knockout pachytene oocytes exhibit reduced HDAC2 and DNMT-1. Notably, mutant oocytes show a striking increase in histone H3 phosphorylation at threonine 3 (H3T3ph) and accumulation of major satellite transcripts in both prophase-I and metaphase-I chromosomes. Moreover, knockout oocytes exhibit centromere fusions, ectopic kinetochore formation and abnormal exchange of chromatin fibers between paired bivalents and asynapsed chromosomes. Our results indicate that loss of LSH affects the levels and chromosomal localization of H3T3ph and provide evidence that, by maintaining transcriptionally repressive heterochromatin, LSH may be essential to prevent deleterious meiotic recombination events at repetitive centromeric sequences.
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Affiliation(s)
- Claudia Baumann
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
- Regenerative Biosciences Center (RBC), University of Georgia, Athens, GA, 30602, USA
| | - Wei Ma
- School of Basic Medical Sciences, Capital Medical University, 100069, Beijing, China
| | - Xiaotian Wang
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
- Regenerative Biosciences Center (RBC), University of Georgia, Athens, GA, 30602, USA
| | | | - Maria M Viveiros
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
- Regenerative Biosciences Center (RBC), University of Georgia, Athens, GA, 30602, USA
| | - Rabindranath De La Fuente
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA.
- Regenerative Biosciences Center (RBC), University of Georgia, Athens, GA, 30602, USA.
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12
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Shao J, Xu Y, Fang M. BRG1 deficiency in endothelial cells alleviates thioacetamide induced liver fibrosis in mice. Biochem Biophys Res Commun 2019; 521:212-219. [PMID: 31635808 DOI: 10.1016/j.bbrc.2019.10.109] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 10/12/2019] [Indexed: 12/11/2022]
Abstract
Liver sinusoidal endothelial cells play a key role maintaining the hepatic homeostasis, the disruption of which is associated with such end-stage liver diseases as hepatocellular carcinoma and cirrhosis. In the present study we investigated the role of brahma-related gene 1 (BRG1), a chromatin remodeling protein, in regulating endothelial transcription and the implication in liver fibrosis. We report that endothelial-specific deletion of BRG1 in mice attenuated liver fibrosis induced by injection with thioacetamide (TAA). Coincidently, alleviation of liver fibrosis as a result of endothelial BRG1 deletion was accompanied by an up-regulation of eNOS activity and NO bioavailability. In cultured endothelial cells, exposure to lipopolysaccharide (LPS) suppressed eNOS activity whereas BRG1 depletion with small interfering RNA restored eNOS-dependent NO production. Further analysis revealed that BRG1 was recruited to the caveolin-1 (CAV1) promoter by Sp1 and activated transcription of CAV1, which in turn inhibited eNOS activity. Mechanistically, BRG1 interacted with the H3K4 trimethyltransferase MLL1 to modulate H3K4 trimethylation surrounding the CAV1 promoter thereby contributing to LPS-induced CAV1 activation. In conclusion, our data unveil a novel role for BRG1 in the regulation of endothelial function and liver fibrosis.
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Affiliation(s)
- Jing Shao
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Yong Xu
- Institute of Biomedical Research, Liaocheng University, Liaocheng, China
| | - Mingming Fang
- Department of Clinical Medicine and Center for Experimental Medicine, Jiangsu Health Vocational College, Nanjing, China; Institute of Biomedical Research, Liaocheng University, Liaocheng, China.
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13
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Mei L, Alikhan M, Mujacic I, Parilla M, Antic T. Genomic Alterations in Undifferentiated Malignant Tumors with Rhabdoid Phenotype and Loss of BRG1 Immunoexpression Identified by Fine Needle Aspirates. Acta Cytol 2019; 63:438-444. [PMID: 31230044 DOI: 10.1159/000500684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/30/2019] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Evidence shows that the switch/sucrose nonfermenting chromatin remodeling complex plays a critical role in DNA repair, cancer progression and dedifferentiation. BRG1 is one of its key catalytic subunits. While the loss of BRG1 expression by immunocytochemistry has been identified in a subset of malignancies arising in various sites with undifferentiated/rhabdoid morphology and poor prognosis, the underlying basis for its loss is unclear. METHODS A retrospective search was conducted in our cytopathology archive for undifferentiated malignant tumors with rhabdoid phenotype and BRG1 loss. Clinical information was obtained from electronic medical records. Next-generation sequencing was performed following macro-dissection of paraffin-embedded cellblock tissue. RESULTS Three cases were identified; all presented with widely metastatic disease with no previously diagnosed primary malignancy, and subsequently died within 6 months of initial presentation. Cytologically, the aspirates showed dyshesive and undifferentiated cells with rhabdoid features. Extensive immunocytochemical workup demonstrated immunoreactivity with vimentin only and could not establish a specific lineage. BRG1 expression was absent, while INI1 expression was retained. Two cases harbored deleterious mutations in BRG1/SMARCA4. Pathogenic mutations in TP53 were identified in all tumors. CONCLUSIONS BRG1 deficiency reflects underlying mutation in SMARCA4 gene in some but not all cases, suggesting that additional mechanisms may be causing BRG1 silencing. Pathogenic mutations in TP53 in all tumors are consistent with their highly aggressive nature. Recognizing the cytomorphology of this group of neoplasms and confirming their BRG1-deficient status by immunocytochemistry not only has prognostic implications, but may also impart potentially therapeutic value in the near future.
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Affiliation(s)
- Lily Mei
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA
| | - Mir Alikhan
- Department of Pathology and Laboratory Medicine, NorthShore University HealthSystem, Evanston, Illinois, USA
| | - Ibro Mujacic
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA
| | - Megan Parilla
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA
| | - Tatjana Antic
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA,
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14
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Belmonte FR, Dedousis N, Sipula I, Desai NA, Singhi AD, Chu Y, Zhang Y, Bannwarth S, Paquis-Flucklinger V, Harrington L, Shiva S, Jurczak MJ, O’Doherty RM, Kaufman BA. Petite Integration Factor 1 (PIF1) helicase deficiency increases weight gain in Western diet-fed female mice without increased inflammatory markers or decreased glucose clearance. PLoS One 2019; 14:e0203101. [PMID: 31136580 PMCID: PMC6538152 DOI: 10.1371/journal.pone.0203101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 05/09/2019] [Indexed: 11/19/2022] Open
Abstract
Petite Integration Factor 1 (PIF1) is a multifunctional helicase present in nuclei and mitochondria. PIF1 knock out (KO) mice exhibit accelerated weight gain and decreased wheel running on a normal chow diet. In the current study, we investigated whether Pif1 ablation alters whole body metabolism in response to weight gain. PIF1 KO and wild type (WT) C57BL/6J mice were fed a Western diet (WD) rich in fat and carbohydrates before evaluation of their metabolic phenotype. Compared with weight gain-resistant WT female mice, WD-fed PIF1 KO females, but not males, showed accelerated adipose deposition, decreased locomotor activity, and reduced whole-body energy expenditure without increased dietary intake. Surprisingly, PIF1 KO females did not show obesity-induced alterations in fasting blood glucose and glucose clearance. WD-fed PIF1 KO females developed mild hepatic steatosis and associated changes in liver gene expression that were absent in weight-matched, WD-fed female controls, linking hepatic steatosis to Pif1 ablation rather than increased body weight. WD-fed PIF1 KO females also showed decreased expression of inflammation-associated genes in adipose tissue. Collectively, these data separated weight gain from inflammation and impaired glucose homeostasis. They also support a role for Pif1 in weight gain resistance and liver metabolic dysregulation during nutrient stress.
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Affiliation(s)
- Frances R. Belmonte
- University of Pittsburgh School of Medicine, Division of Cardiology, Center for Metabolism and Mitochondrial Medicine, and Vascular Medicine Institute, Pittsburgh, PA, United States of America
| | - Nikolaos Dedousis
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Biomedical Science Tower, Pittsburgh, PA, United States of America
| | - Ian Sipula
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Biomedical Science Tower, Pittsburgh, PA, United States of America
| | - Nikita A. Desai
- University of Pittsburgh School of Medicine, Division of Cardiology, Center for Metabolism and Mitochondrial Medicine, and Vascular Medicine Institute, Pittsburgh, PA, United States of America
| | - Aatur D. Singhi
- Department of Pathology and Pittsburgh Liver Research Center, University of Pittsburgh, Scaife Hall, Pittsburgh, PA, United States of America
| | - Yanxia Chu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, UPMC Montefiore Hospital, Pittsburgh, PA, United States of America
| | - Yingze Zhang
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, UPMC Montefiore Hospital, Pittsburgh, PA, United States of America
| | - Sylvie Bannwarth
- Université Côte d'Azur, CHU de Nice, Inserm, CNRS, IRCAN, France
| | | | - Lea Harrington
- Université de Montréal, Institut de Recherche en Immunologie et en Cancérologie, Montréal, Québec, Canada
| | - Sruti Shiva
- University of Pittsburgh School of Medicine, Division of Cardiology, Center for Metabolism and Mitochondrial Medicine, and Vascular Medicine Institute, Pittsburgh, PA, United States of America
| | - Michael J. Jurczak
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Biomedical Science Tower, Pittsburgh, PA, United States of America
| | - Robert M. O’Doherty
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Biomedical Science Tower, Pittsburgh, PA, United States of America
| | - Brett A. Kaufman
- University of Pittsburgh School of Medicine, Division of Cardiology, Center for Metabolism and Mitochondrial Medicine, and Vascular Medicine Institute, Pittsburgh, PA, United States of America
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15
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Augello MA, Liu D, Deonarine LD, Robinson BD, Huang D, Stelloo S, Blattner M, Doane AS, Wong EWP, Chen Y, Rubin MA, Beltran H, Elemento O, Bergman AM, Zwart W, Sboner A, Dephoure N, Barbieri CE. CHD1 Loss Alters AR Binding at Lineage-Specific Enhancers and Modulates Distinct Transcriptional Programs to Drive Prostate Tumorigenesis. Cancer Cell 2019; 35:603-617.e8. [PMID: 30930119 PMCID: PMC6467783 DOI: 10.1016/j.ccell.2019.03.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/06/2018] [Accepted: 02/28/2019] [Indexed: 12/11/2022]
Abstract
Deletion of the gene encoding the chromatin remodeler CHD1 is among the most common alterations in prostate cancer (PCa); however, the tumor-suppressive functions of CHD1 and reasons for its tissue-specific loss remain undefined. We demonstrated that CHD1 occupied prostate-specific enhancers enriched for the androgen receptor (AR) and lineage-specific cofactors. Upon CHD1 loss, the AR cistrome was redistributed in patterns consistent with the oncogenic AR cistrome in PCa samples and drove tumor formation in the murine prostate. Notably, this cistrome shift was associated with a unique AR transcriptional signature enriched for pro-oncogenic pathways unique to this tumor subclass. Collectively, these data credential CHD1 as a tumor suppressor in the prostate that constrains AR binding/function to limit tumor progression.
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Affiliation(s)
- Michael A Augello
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA
| | - Deli Liu
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Lesa D Deonarine
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA
| | - Brian D Robinson
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Dennis Huang
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA
| | - Suzan Stelloo
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Mirjam Blattner
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ashley S Doane
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Elissa W P Wong
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yu Chen
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Mark A Rubin
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Himisha Beltran
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA; Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Olivier Elemento
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10065, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Andries M Bergman
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands; Division of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Wilbert Zwart
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands; Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Andrea Sboner
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10065, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Noah Dephoure
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Christopher E Barbieri
- Department of Urology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA; Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10065, USA.
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16
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Matsushita M, Kuwamoto S. Cytologic Features of SMARCA4-Deficient Thoracic Sarcoma: A Case Report and Comparison with Other SWI/SNF Complex-Deficient Tumors. Acta Cytol 2018; 62:456-462. [PMID: 30286456 DOI: 10.1159/000493335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 08/29/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND SMARCA4-deficient thoracic sarcoma is a recently proposed entity of soft tissue tumors associated with an extremely poor prognosis. Its cytologic features have not been well described in the literature yet. CASE A woman in her early 30s who presented with chest pain was found to have a tumor in the right chest wall. Cytologic smears revealed numerous atypical round-to-polygonal cells appearing singly or in loosely cohesive clusters. These cells had a well-defined cell border, scant-to-moderate cytoplasm, and enlarged vesicular nuclei with prominent nucleoli. In addition, some cells with eosinophilic globular intracytoplasmic inclusions and eccentrically located nuclei, consistent with rhabdoid cells, were observed. Immunocytochemically, the cells were at least focally positive for cytokeratin CAM5.2 and CD34 and showed a significantly reduced BRG1/SMARCA4 expression. The diagnosis was confirmed by histological, immunohistochemical, and genetic analysis of a metastatic lesion to the left axillary lymph node. CONCLUSION Although the cytologic features of SMARCA4-deficient thoracic sarcoma are not fully unique, they are sufficiently characteristic to suspect this tumor in cases of supporting clinical and radiological features, which may promote additional immunological or molecular testing to establish a definitive diagnosis.
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Affiliation(s)
- Michiko Matsushita
- Department of Pathobiological Science and Technology, School of Health Science, Faculty of Medicine, Tottori University, Yonago, Japan
- Division of Molecular Pathology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Satoshi Kuwamoto
- Division of Molecular Pathology, Faculty of Medicine, Tottori University, Yonago,
- Department of Pathology, Tottori University Hospital, Yonago,
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17
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Tsuda M, Cho K, Ooka M, Shimizu N, Watanabe R, Yasui A, Nakazawa Y, Ogi T, Harada H, Agama K, Nakamura J, Asada R, Fujiike H, Sakuma T, Yamamoto T, Murai J, Hiraoka M, Koike K, Pommier Y, Takeda S, Hirota K. ALC1/CHD1L, a chromatin-remodeling enzyme, is required for efficient base excision repair. PLoS One 2017; 12:e0188320. [PMID: 29149203 PMCID: PMC5693467 DOI: 10.1371/journal.pone.0188320] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/03/2017] [Indexed: 11/18/2022] Open
Abstract
ALC1/CHD1L is a member of the SNF2 superfamily of ATPases carrying a macrodomain that binds poly(ADP-ribose). Poly(ADP-ribose) polymerase (PARP) 1 and 2 synthesize poly(ADP-ribose) at DNA-strand cleavage sites, promoting base excision repair (BER). Although depletion of ALC1 causes increased sensitivity to various DNA-damaging agents (H2O2, UV, and phleomycin), the role played by ALC1 in BER has not yet been established. To explore this role, as well as the role of ALC1’s ATPase activity in BER, we disrupted the ALC1 gene and inserted the ATPase-dead (E165Q) mutation into the ALC1 gene in chicken DT40 cells, which do not express PARP2. The resulting ALC1-/- and ALC1-/E165Q cells displayed an indistinguishable hypersensitivity to methylmethane sulfonate (MMS), an alkylating agent, and to H2O2, indicating that ATPase plays an essential role in the DNA-damage response. PARP1-/- and ALC1-/-/PARP1-/- cells exhibited a very similar sensitivity to MMS, suggesting that ALC1 and PARP1 collaborate in BER. Following pulse-exposure to H2O2, PARP1-/- and ALC1-/-/PARP1-/- cells showed similarly delayed kinetics in the repair of single-strand breaks, which arise as BER intermediates. To ascertain ALC1’s role in BER in mammalian cells, we disrupted the ALC1 gene in human TK6 cells. Following exposure to MMS and to H2O2, the ALC1-/- TK6 cell line showed a delay in single-strand-break repair. We therefore conclude that ALC1 plays a role in BER. Following exposure to H2O2,ALC1-/- cells showed compromised chromatin relaxation. We thus propose that ALC1 is a unique BER factor that functions in a chromatin context, most likely as a chromatin-remodeling enzyme.
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Affiliation(s)
- Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Kosai Cho
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Masato Ooka
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
| | - Naoto Shimizu
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Reiko Watanabe
- Division of Dynamic Proteome, Institute of Development, Aging and Cancer, Tohoku University, Seiryomachi 4–1, Aobaku, Sendai, Japan
| | - Akira Yasui
- Division of Dynamic Proteome, Institute of Development, Aging and Cancer, Tohoku University, Seiryomachi 4–1, Aobaku, Sendai, Japan
| | - Yuka Nakazawa
- Department of Genome Repair, Atomic Bomb Disease Institute, Nagasaki University Sakamoto, Nagasaki, Japan
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Tomoo Ogi
- Department of Genome Repair, Atomic Bomb Disease Institute, Nagasaki University Sakamoto, Nagasaki, Japan
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Hiroshi Harada
- Laboratory of Cancer Cell Biology, Radiation Biology Center, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Keli Agama
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Jun Nakamura
- Department of Environmental Sciences and Engineering, University of North Carolina Chapel Hill, North Carolina, United States of America
| | - Ryuta Asada
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
| | - Haruna Fujiike
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Tetsushi Sakuma
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - Junko Murai
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Masahiro Hiraoka
- Department of Radiation Oncology, Japanese Red Cross Society Wakayama Medical Center, Komatsubara-Dori, Wakayama, Japan
| | - Kaoru Koike
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- * E-mail: (KH); (ST)
| | - Kouji Hirota
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
- * E-mail: (KH); (ST)
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18
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Caputo M, Balzerano A, Arisi I, D’Onofrio M, Brandi R, Bongiorni S, Brancorsini S, Frontini M, Proietti-De-Santis L. CSB ablation induced apoptosis is mediated by increased endoplasmic reticulum stress response. PLoS One 2017; 12:e0172399. [PMID: 28253359 PMCID: PMC5333825 DOI: 10.1371/journal.pone.0172399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 02/03/2017] [Indexed: 12/17/2022] Open
Abstract
The DNA repair protein Cockayne syndrome group B (CSB) has been recently identified as a promising anticancer target. Suppression, by antisense technology, of this protein causes devastating effects on tumor cells viability, through a massive induction of apoptosis, while being non-toxic to non-transformed cells. To gain insights into the mechanisms underlying the pro-apoptotic effects observed after CSB ablation, global gene expression patterns were determined, to identify genes that were significantly differentially regulated as a function of CSB expression. Our findings revealed that response to endoplasmic reticulum stress and response to unfolded proteins were ranked top amongst the cellular processes affected by CSB suppression. The major components of the endoplasmic reticulum stress-mediated apoptosis pathway, including pro-apoptotic factors downstream of the ATF3-CHOP cascade, were dramatically up-regulated. Altogether our findings add new pieces to the understanding of CSB mechanisms of action and to the molecular basis of CS syndrome.
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Affiliation(s)
- Manuela Caputo
- Unit of Molecular Genetics of Aging—Department of Ecology and Biology—University of Tuscia, Viterbo, Italy
| | - Alessio Balzerano
- Unit of Molecular Genetics of Aging—Department of Ecology and Biology—University of Tuscia, Viterbo, Italy
| | - Ivan Arisi
- Genomics Facility, European Brain Research Institute (EBRI) “Rita Levi-Montalcini”, Rome, Italy
| | - Mara D’Onofrio
- Genomics Facility, European Brain Research Institute (EBRI) “Rita Levi-Montalcini”, Rome, Italy
| | - Rossella Brandi
- Genomics Facility, European Brain Research Institute (EBRI) “Rita Levi-Montalcini”, Rome, Italy
| | - Silvia Bongiorni
- Unit of Molecular Genetics of Aging—Department of Ecology and Biology—University of Tuscia, Viterbo, Italy
| | - Stefano Brancorsini
- Department of Experimental Medicine—Section of Terni, University of Perugia, Terni, Italy
| | - Mattia Frontini
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- British Heart Foundation Centre of Excellence, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Luca Proietti-De-Santis
- Unit of Molecular Genetics of Aging—Department of Ecology and Biology—University of Tuscia, Viterbo, Italy
- * E-mail:
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19
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Crosswhite PL, Podsiadlowska JJ, Curtis CD, Gao S, Xia L, Srinivasan RS, Griffin CT. CHD4-regulated plasmin activation impacts lymphovenous hemostasis and hepatic vascular integrity. J Clin Invest 2016; 126:2254-66. [PMID: 27140400 DOI: 10.1172/jci84652] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 03/10/2016] [Indexed: 12/11/2022] Open
Abstract
The chromatin-remodeling enzyme CHD4 maintains vascular integrity at mid-gestation; however, it is unknown whether this enzyme contributes to later blood vessel or lymphatic vessel development. Here, we addressed this issue in mice harboring a deletion of Chd4 specifically in cells that express lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1), which include lymphatic endothelial cells (LECs) and liver sinusoidal endothelial cells. Chd4 mutant embryos died before birth and exhibited severe edema, blood-filled lymphatics, and liver hemorrhage. CHD4-deficient embryos developed normal lymphovenous (LV) valves, which regulate the return of lymph to the blood circulation; however, these valves lacked the fibrin-rich thrombi that prevent blood from entering the lymphatic system. Transcripts of the urokinase plasminogen activator receptor (uPAR), which facilitates activation of the fibrin-degrading protease plasmin, were upregulated in Chd4 mutant LYVE1+ cells, and plasmin activity was elevated near the LV valves. Genetic reduction of the uPAR ligand urokinase prevented degradation of fibrin-rich thrombi at the LV valves and largely resolved the blood-filled lymphatics in Chd4 mutants. Urokinase reduction also ameliorated liver hemorrhage and prolonged embryonic survival by reducing plasmin-mediated extracellular matrix degradation around sinusoidal blood vessels. These results highlight the susceptibility of LV thrombi and liver sinusoidal vessels to plasmin-mediated damage and demonstrate the importance of CHD4 in regulating embryonic plasmin activation after mid-gestation.
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20
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Tkáč J, Xu G, Adhikary H, Young JTF, Gallo D, Escribano-Díaz C, Krietsch J, Orthwein A, Munro M, Sol W, Al-Hakim A, Lin ZY, Jonkers J, Borst P, Brown GW, Gingras AC, Rottenberg S, Masson JY, Durocher D. HELB Is a Feedback Inhibitor of DNA End Resection. Mol Cell 2016; 61:405-418. [PMID: 26774285 DOI: 10.1016/j.molcel.2015.12.013] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 11/04/2015] [Accepted: 12/03/2015] [Indexed: 12/13/2022]
Abstract
DNA double-strand break repair by homologous recombination is initiated by the formation of 3' single-stranded DNA (ssDNA) overhangs by a process termed end resection. Although much focus has been given to the decision to initiate resection, little is known of the mechanisms that regulate the ongoing formation of ssDNA tails. Here we report that DNA helicase B (HELB) underpins a feedback inhibition mechanism that curtails resection. HELB is recruited to ssDNA by interacting with RPA and uses its 5'-3' ssDNA translocase activity to inhibit EXO1 and BLM-DNA2, the nucleases catalyzing resection. HELB acts independently of 53BP1 and is exported from the nucleus as cells approach S phase, concomitant with the upregulation of resection. Consistent with its role as a resection antagonist, loss of HELB results in PARP inhibitor resistance in BRCA1-deficient tumor cells. We conclude that mammalian DNA end resection triggers its own inhibition via the recruitment of HELB.
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MESH Headings
- Animals
- BRCA1 Protein/genetics
- DNA End-Joining Repair
- DNA Helicases/deficiency
- DNA Helicases/genetics
- DNA Helicases/metabolism
- DNA Repair Enzymes/genetics
- DNA Repair Enzymes/metabolism
- Exodeoxyribonucleases/genetics
- Exodeoxyribonucleases/metabolism
- Feedback, Physiological
- Female
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- HEK293 Cells
- HeLa Cells
- Humans
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/enzymology
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/pathology
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Knockout
- Phthalazines/pharmacology
- Piperazines/pharmacology
- Poly(ADP-ribose) Polymerase Inhibitors/pharmacology
- RNA Interference
- RecQ Helicases/genetics
- RecQ Helicases/metabolism
- S Phase
- Time Factors
- Transfection
- Tumor Suppressor Proteins/genetics
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Affiliation(s)
- Ján Tkáč
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, ON M5S 1A8, Canada
| | - Guotai Xu
- Division of Molecular Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Hemanta Adhikary
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada
| | - Jordan T F Young
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, ON M5S 1A8, Canada
| | - David Gallo
- Department of Biochemistry and Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, ON M5S 3E1, Canada
| | - Cristina Escribano-Díaz
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Jana Krietsch
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada
| | - Alexandre Orthwein
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Meagan Munro
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Wendy Sol
- Division of Molecular Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Abdallah Al-Hakim
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Zhen-Yuan Lin
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Jos Jonkers
- Division of Molecular Pathology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Piet Borst
- Division of Molecular Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, ON M5S 3E1, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, ON M5S 1A8, Canada
| | - Sven Rottenberg
- Division of Molecular Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Laenggasstrasse 122, 3012 Bern, Switzerland
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada
| | - Daniel Durocher
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, ON M5S 1A8, Canada.
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21
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Fedeles SV, So JS, Shrikhande A, Lee SH, Gallagher AR, Barkauskas CE, Somlo S, Lee AH. Sec63 and Xbp1 regulate IRE1α activity and polycystic disease severity. J Clin Invest 2015; 125:1955-67. [PMID: 25844898 DOI: 10.1172/jci78863] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/19/2015] [Indexed: 12/14/2022] Open
Abstract
The HSP40 cochaperone SEC63 is associated with the SEC61 translocon complex in the ER. Mutations in the gene encoding SEC63 cause polycystic liver disease in humans; however, it is not clear how altered SEC63 influences disease manifestations. In mice, loss of SEC63 induces cyst formation both in liver and kidney as the result of reduced polycystin-1 (PC1). Here we report that inactivation of SEC63 induces an unfolded protein response (UPR) pathway that is protective against cyst formation. Specifically, using murine genetic models, we determined that SEC63 deficiency selectively activates the IRE1α-XBP1 branch of UPR and that SEC63 exists in a complex with PC1. Concomitant inactivation of both SEC63 and XBP1 exacerbated the polycystic kidney phenotype in mice by markedly suppressing cleavage at the G protein-coupled receptor proteolysis site (GPS) in PC1. Enforced expression of spliced XBP1 (XBP1s) enhanced GPS cleavage of PC1 in SEC63-deficient cells, and XBP1 overexpression in vivo ameliorated cystic disease in a murine model with reduced PC1 function that is unrelated to SEC63 inactivation. Collectively, the findings show that SEC63 function regulates IRE1α/XBP1 activation, SEC63 and XBP1 are required for GPS cleavage and maturation of PC1, and activation of XBP1 can protect against polycystic disease in the setting of impaired biogenesis of PC1.
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MESH Headings
- Animals
- Cell Line
- DNA Helicases/deficiency
- DNA Helicases/genetics
- DNA Helicases/physiology
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Disease Models, Animal
- Endoribonucleases/metabolism
- Female
- Glucosidases/deficiency
- Glucosidases/genetics
- Intracellular Signaling Peptides and Proteins/deficiency
- Intracellular Signaling Peptides and Proteins/genetics
- Kidney/metabolism
- Kidney/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Molecular Chaperones
- Polycystic Kidney, Autosomal Dominant/genetics
- Polycystic Kidney, Autosomal Dominant/metabolism
- Polycystic Kidney, Autosomal Recessive/genetics
- Polycystic Kidney, Autosomal Recessive/metabolism
- Protein Serine-Threonine Kinases/metabolism
- Protein Structure, Tertiary
- RNA Splicing
- RNA, Small Interfering/genetics
- RNA-Binding Proteins
- Receptors, G-Protein-Coupled/metabolism
- Recombinant Fusion Proteins/metabolism
- Regulatory Factor X Transcription Factors
- TRPP Cation Channels/biosynthesis
- TRPP Cation Channels/deficiency
- TRPP Cation Channels/genetics
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/physiology
- Transfection
- Unfolded Protein Response/physiology
- X-Box Binding Protein 1
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22
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Hu Z, Cools T, Kalhorzadeh P, Heyman J, De Veylder L. Deficiency of the Arabidopsis helicase RTEL1 triggers a SOG1-dependent replication checkpoint in response to DNA cross-links. Plant Cell 2015; 27:149-61. [PMID: 25595823 PMCID: PMC4330584 DOI: 10.1105/tpc.114.134312] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
To maintain genome integrity, DNA replication is executed and regulated by a complex molecular network of numerous proteins, including helicases and cell cycle checkpoint regulators. Through a systematic screening for putative replication mutants, we identified an Arabidopsis thaliana homolog of human Regulator of Telomere Length 1 (RTEL1), which functions in DNA replication, DNA repair, and recombination. RTEL1 deficiency retards plant growth, a phenotype including a prolonged S-phase duration and decreased cell proliferation. Genetic analysis revealed that rtel1 mutant plants show activated cell cycle checkpoints, specific sensitivity to DNA cross-linking agents, and increased homologous recombination, but a lack of progressive shortening of telomeres, indicating that RTEL1 functions have only been partially conserved between mammals and plants. Surprisingly, RTEL1 deficiency induces tolerance to the deoxynucleotide-depleting drug hydroxyurea, which could be mimicked by DNA cross-linking agents. This resistance does not rely on the essential replication checkpoint regulator WEE1 but could be blocked by a mutation in the SOG1 transcription factor. Taken together, our data indicate that RTEL1 is required for DNA replication and that its deficiency activates a SOG1-dependent replication checkpoint.
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Affiliation(s)
- Zhubing Hu
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Toon Cools
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Pooneh Kalhorzadeh
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Jefri Heyman
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Lieven De Veylder
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
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23
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Rao Q, Xia QY, Shen Q, Shi SS, Tu P, Shi QL, Zhou XJ. Coexistent loss of INI1 and BRG1 expression in a rhabdoid renal cell carcinoma (RCC): implications for a possible role of SWI/SNF complex in the pathogenesis of RCC. Int J Clin Exp Pathol 2014; 7:1782-1787. [PMID: 24817979 PMCID: PMC4014263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 02/23/2014] [Indexed: 06/03/2023]
Abstract
In this study, we analyzed the immunohistochemical and molecular profiles of an unusual RCC showed coexistent absence of INI1 and BRG1 expression, rhabdoid morphology, and poor prognosis. Histologically, the tumor had rhabdoid features, which were demonstrated by large round to polygonal cells with eccentric nuclei, prominent nucleoli, and eosinophilic cytoplasm varying from abundant to scanty. Immunohistochemically, the tumor were positive for BRM, PBRM1, ARID1A, CD10, CKpan, Vimentin, carbonic anhydrase IX (CA-IX), and P504S (AMACR) but negative for INI1, BRG1, HMB45, melan A, CK7, CD117, Ksp-cadherin, TFEB, TFE3, and Cathepsin K. We detected all three exons status of the VHL gene of the tumor and observed 1 somatic mutations in 1st exon. Chromosome 3p deletion, coupled with polysomy of chromosome 3 was also found. Based on these findings, it is further indicated that in some cases, rhabdoid RCC may arise from clear cell RCC. SWI/SNF chromatin remodeling complex may be an attractive candidate for being the "second hit" in RCCs and may play an important role during tumor progression. The role of SWI/SNF complex in rhabdoid RCC should be further studied on a larger number of cases.
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Affiliation(s)
- Qiu Rao
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Qiu-Yuan Xia
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Qin Shen
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Shan-Shan Shi
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Pin Tu
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Qun-Li Shi
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
| | - Xiao-Jun Zhou
- Department of Pathology, Nanjing Jinling Hospital, Nanjing University School of Medicine Nanjing, China
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24
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Adelman CA, Lolo RL, Birkbak NJ, Murina O, Matsuzaki K, Horejsi Z, Parmar K, Borel V, Skehel JM, Stamp G, D’Andrea A, Sartori AA, Swanton C, Boulton SJ. HELQ promotes RAD51 paralogue-dependent repair to avert germ cell loss and tumorigenesis. Nature 2013; 502:381-4. [PMID: 24005329 PMCID: PMC3836231 DOI: 10.1038/nature12565] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/15/2013] [Indexed: 12/13/2022]
Abstract
Repair of interstrand crosslinks (ICLs) requires the coordinated action of the intra-S-phase checkpoint and the Fanconi anaemia pathway, which promote ICL incision, translesion synthesis and homologous recombination (reviewed in refs 1, 2). Previous studies have implicated the 3'-5' superfamily 2 helicase HELQ in ICL repair in Drosophila melanogaster (MUS301 (ref. 3)) and Caenorhabditis elegans (HELQ-1 (ref. 4)). Although in vitro analysis suggests that HELQ preferentially unwinds synthetic replication fork substrates with 3' single-stranded DNA overhangs and also disrupts protein-DNA interactions while translocating along DNA, little is known regarding its functions in mammalian organisms. Here we report that HELQ helicase-deficient mice exhibit subfertility, germ cell attrition, ICL sensitivity and tumour predisposition, with Helq heterozygous mice exhibiting a similar, albeit less severe, phenotype than the null, indicative of haploinsufficiency. We establish that HELQ interacts directly with the RAD51 paralogue complex BCDX2 and functions in parallel to the Fanconi anaemia pathway to promote efficient homologous recombination at damaged replication forks. Thus, our results reveal a critical role for HELQ in replication-coupled DNA repair, germ cell maintenance and tumour suppression in mammals.
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Affiliation(s)
- Carrie A. Adelman
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Rafal L. Lolo
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Nicolai J. Birkbak
- Center for Biological Sequence Analysis, Technical University of Denmark, Lyngby, Denmark
| | - Olga Murina
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Kenichiro Matsuzaki
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Zuzana Horejsi
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Kalindi Parmar
- Department of Radiation Oncology, Dana Farber Cancer Institute, Boston, Massachusetts, 02215, USA
| | - Valérie Borel
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - J. Mark Skehel
- Protein Analysis and Proteomics Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Gordon Stamp
- Experimental Histopathology Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London, WC2A 3LY, UK
| | - Alan D’Andrea
- Department of Radiation Oncology, Dana Farber Cancer Institute, Boston, Massachusetts, 02215, USA
| | - Alessandro A. Sartori
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Charles Swanton
- Translational Cancer Therapeutics Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London, WC2A 3LY, UK
- UCL Cancer Institute, Huntley Street, London, WC1E 6DD
| | - Simon J. Boulton
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
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Yao Y, Bilichak A, Titov V, Golubov A, Kovalchuk I. Genome stability of Arabidopsis atm, ku80 and rad51b mutants: somatic and transgenerational responses to stress. Plant Cell Physiol 2013; 54:982-9. [PMID: 23574700 DOI: 10.1093/pcp/pct051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
DNA double-strand breaks (DSBs) can be repaired via two main mechanisms: non-homologous end joining (NHEJ) and homologous recombination (HR). Our previous work showed that exposure to abiotic stresses resulted in an increase in point mutation frequency (PMF) and homologous recombination frequency (HRF), and these changes were heritable. We hypothesized that mutants impaired in DSB recognition and repair would also be deficient in somatic and transgenerational changes in PMF and HRF. To test this hypothesis, we analyzed the genome stability of the Arabidopsis thaliana mutants deficient in ATM (communication between DNA strand break recognition and the repair machinery), KU80 (deficient in NHEJ) and RAD51B (deficient in HR repair) genes. We found that all three mutants exhibited higher levels of DSBs. Plants impaired in ATM had a lower spontaneous PMF and HRF, whereas ku80 plants had higher frequencies. Plants impaired in RAD51B had a lower HRF. HRF in wild-type, atm and rad51b plants increased in response to several abiotic stressors, whereas it did not increase in ku80 plants. The progeny of stressed wild-type and ku80 plants exhibited an increase in HRF in response to all stresses, and the increase was higher in ku80 plants. The progeny of atm plants showed an increase in HRF only when the parental generation was exposed to cold or flood, whereas the progeny of rad51b plants completely lacked a transgenerational increase in HRF. Our experiments showed that mutants impaired in the recognition and repair of DSBs exhibited changes in the efficiency of DNA repair as reflected by changes in strand breaks, point mutation and HRF. They also showed that the HR RAD51B protein and the protein ATM that recognized damaged DNA might play an important role in transgenerational changes in HRF.
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Affiliation(s)
- Youli Yao
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
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Dykhuizen EC, Hargreaves DC, Miller EL, Cui K, Korshunov A, Kool M, Pfister S, Cho YJ, Zhao K, Crabtree GR. BAF complexes facilitate decatenation of DNA by topoisomerase IIα. Nature 2013; 497:624-7. [PMID: 23698369 PMCID: PMC3668793 DOI: 10.1038/nature12146] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 04/03/2013] [Indexed: 12/19/2022]
Abstract
Recent exon-sequencing studies of human tumours have revealed that subunits of BAF (mammalian SWI/SNF) complexes are mutated in more than 20% of all human malignancies, but the mechanisms involved in tumour suppression are unclear. BAF chromatin-remodelling complexes are polymorphic assemblies that use energy provided by ATP hydrolysis to regulate transcription through the control of chromatin structure and the placement of Polycomb repressive complex 2 (PRC2) across the genome. Several proteins dedicated to this multisubunit complex, including BRG1 (also known as SMARCA4) and BAF250a (also known as ARID1A), are mutated at frequencies similar to those of recognized tumour suppressors. In particular, the core ATPase BRG1 is mutated in 5-10% of childhood medulloblastomas and more than 15% of Burkitt's lymphomas. Here we show a previously unknown function of BAF complexes in decatenating newly replicated sister chromatids, a requirement for proper chromosome segregation during mitosis. We find that deletion of Brg1 in mouse cells, as well as the expression of BRG1 point mutants identified in human tumours, leads to anaphase bridge formation (in which sister chromatids are linked by catenated strands of DNA) and a G2/M-phase block characteristic of the decatenation checkpoint. Endogenous BAF complexes interact directly with endogenous topoisomerase IIα (TOP2A) through BAF250a and are required for the binding of TOP2A to approximately 12,000 sites across the genome. Our results demonstrate that TOP2A chromatin binding is dependent on the ATPase activity of BRG1, which is compromised in oncogenic BRG1 mutants. These studies indicate that the ability of TOP2A to prevent DNA entanglement at mitosis requires BAF complexes and suggest that this activity contributes to the role of BAF subunits as tumour suppressors.
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Affiliation(s)
- Emily C Dykhuizen
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA
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27
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Gabrielli N, Ayté J, Hidalgo E. Cells lacking pfh1, a fission yeast homolog of mammalian frataxin protein, display constitutive activation of the iron starvation response. J Biol Chem 2012; 287:43042-51. [PMID: 23115244 PMCID: PMC3522298 DOI: 10.1074/jbc.m112.421735] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/27/2012] [Indexed: 11/06/2022] Open
Abstract
Friedreich ataxia is a genetic disease caused by deficiencies in frataxin. This protein has homologs not only in higher eukaryotes but also in bacteria, fungi, and plants. The function of this protein is still controversial. We have identified a frataxin homolog in fission yeast, and we have analyzed whether its depletion leads to any of the phenotypes observed in other organisms. Cells deleted in pfh1 are sensitive to growth under aerobic conditions, display increased levels of total iron, hallmarks of oxidative stress such as protein carbonylation, decreased aconitase activity, and lower levels of oxygen consumption compared with wild-type cells. This mitochondrial protein seems to be important for iron and/or reactive oxygen species homeostasis. We have analyzed the proteome of cells devoid of Pfh1, and we determined that gene products up- and down-regulated upon iron depletion in wild-type cells are constitutively misregulated in this mutant. Because of the particular signaling pathway components governing the iron starvation response in fission yeast, our experiments suggest that cells lacking Pfh1 display a decrease of cytosolic available iron that triggers activation of Grx4, the common regulator of the iron starvation gene expression program. Our Schizosaccharomyces pombe Δpfh1 strain constitutes a new and useful model system to study Friedreich ataxia.
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Affiliation(s)
- Natalia Gabrielli
- From the Oxidative Stress and Cell Cycle Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003 Barcelona, Spain
| | - José Ayté
- From the Oxidative Stress and Cell Cycle Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Elena Hidalgo
- From the Oxidative Stress and Cell Cycle Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003 Barcelona, Spain
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Zhou K, Michiels CW, Aertsen A. Variation of intragenic tandem repeat tract of tolA modulates Escherichia coli stress tolerance. PLoS One 2012; 7:e47766. [PMID: 23094082 PMCID: PMC3477136 DOI: 10.1371/journal.pone.0047766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/20/2012] [Indexed: 11/18/2022] Open
Abstract
In recent work we discovered that the intragenic tandem repeat (TR) region of the tolA gene is highly variable among different Escherichia coli strains. The aim of this study was therefore to investigate the biological function and dynamics of TR variation in E. coli tolA. The biological impact of TR variation was examined by comparing the ability of a set of synthetic tolA variants with in frame repeat copies varying from 2 to 39 to rescue the altered susceptibility of an E. coli ΔtolA mutant to deoxycholic acid, sodium dodecyl sulfate, hyperosmolarity, and infection with filamentous bacteriophage. Interestingly, although each of the TolA variants was able to at least partly rescue the ΔtolA mutant, the extent was clearly dependent on both the repeat number and the type of stress imposed, indicating the existence of opposing selective forces with regard to the optimal TR copy number. Subsequently, TR dynamics in a clonal population were assayed, and we could demonstrate that TR contractions are RecA dependent and enhanced in a DNA repair deficient uvrD background, and can occur at a frequency of 6.9×10−5.
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Affiliation(s)
- Kai Zhou
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (MS), Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Chris W. Michiels
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (MS), Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Abram Aertsen
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (MS), Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
- * E-mail:
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29
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Rousseau L, Etienne O, Roque T, Desmaze C, Haton C, Mouthon MA, Bernardino-Sgherri J, Essers J, Kanaar R, Boussin FD. In vivo importance of homologous recombination DNA repair for mouse neural stem and progenitor cells. PLoS One 2012; 7:e37194. [PMID: 22666344 PMCID: PMC3362579 DOI: 10.1371/journal.pone.0037194] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 04/18/2012] [Indexed: 01/15/2023] Open
Abstract
We characterized the in vivo importance of the homologous recombination factor RAD54 for the developing mouse brain cortex in normal conditions or after ionizing radiation exposure. Contrary to numerous homologous recombination genes, Rad54 disruption did not impact the cortical development without exogenous stress, but it dramatically enhanced the radiation sensitivity of neural stem and progenitor cells. This resulted in the death of all cells irradiated during S or G2, whereas the viability of cells irradiated in G1 or G0 was not affected by Rad54 disruption. Apoptosis occurred after long arrests at intra-S and G2/M checkpoints. This concerned every type of neural stem and progenitor cells, showing that the importance of Rad54 for radiation response was linked to the cell cycle phase at the time of irradiation and not to the differentiation state. In the developing brain, RAD54-dependent homologous recombination appeared absolutely required for the repair of damages induced by ionizing radiation during S and G2 phases, but not for the repair of endogenous damages in normal conditions. Altogether our data support the existence of RAD54-dependent and -independent homologous recombination pathways.
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Affiliation(s)
- Laure Rousseau
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Olivier Etienne
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Telma Roque
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Chantal Desmaze
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Céline Haton
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Marc-André Mouthon
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
| | - Jacqueline Bernardino-Sgherri
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
- Laboratoire de Gamétogenèse, Apoptose et Génotoxicité, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
| | - Jeroen Essers
- Department of Cell Biology & Genetics, Cancer Genomics Center, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiation Oncology, Erasmus MC, Rotterdam, The Netherlands
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
| | - Roland Kanaar
- Department of Cell Biology & Genetics, Cancer Genomics Center, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiation Oncology, Erasmus MC, Rotterdam, The Netherlands
| | - François D. Boussin
- Laboratoire de Radiopathologie, SCSR, iRCM, DSV, CEA, Fontenay-aux-Roses, France
- U967, INSERM, Fontenay-aux-Roses, France
- UMR 967, Université Paris Diderot, Sorbonne Paris Cité, Fontenay-aux-Roses, France
- UMR 967, Université Paris Sud, Fontenay-aux-Roses, France
- * E-mail:
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Kim N, Jinks-Robertson S. Guanine repeat-containing sequences confer transcription-dependent instability in an orientation-specific manner in yeast. DNA Repair (Amst) 2011; 10:953-60. [PMID: 21813340 DOI: 10.1016/j.dnarep.2011.07.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/10/2011] [Accepted: 07/07/2011] [Indexed: 11/20/2022]
Abstract
Non-B DNA structures are a major contributor to the genomic instability associated with repetitive sequences. Immunoglobulin switch Mu (Sμ) region sequence is comprised of guanine-rich repeats and has high potential for forming G4 DNA, in which one strand of DNA folds into an array of guanine quartets. Taking advantage of the genetic tractability of Saccharomyces cerevisiae, we developed a recombination assay to investigate mechanisms involved in maintaining stability of G-rich repetitive sequence. By embedding Sμ sequence within recombination substrates under the control of a tetracycline-regulatable promoter, we demonstrate that the rate and orientation of transcription both affect the stability of Sμ sequence. In particular, the greatest instability was observed under high-transcription conditions when the Sμ sequence was oriented with the C-rich strand as the transcription template. The effect of transcription orientation was enhanced in the absence of the Type IB topoisomerase Top1, possibly due to enhanced R-loop formation. Loss of Sgs1 helicase and RNase H activity also increased instability, suggesting they may cooperatively function to reduce the formation of non-B DNA structures in highly transcribed regions. Finally, the Sμ sequence was unstable when transcription elongation was perturbed due to a defective THO complex. In a THO-deficient background, there was further exacerbation of orientation-dependent instability associated with the ectopically expressed, single-strand cytosine deaminase AID. The implications of our findings to understanding instability associated with potential G4 DNA forming sequences are discussed.
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Affiliation(s)
- Nayun Kim
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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31
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Iwai A, Takegami T, Shiozaki T, Miyazaki T. Hepatitis C virus NS3 protein can activate the Notch-signaling pathway through binding to a transcription factor, SRCAP. PLoS One 2011; 6:e20718. [PMID: 21673954 PMCID: PMC3108961 DOI: 10.1371/journal.pone.0020718] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/09/2011] [Indexed: 11/18/2022] Open
Abstract
Persistent infections of hepatitis C virus (HCV) are known to be a major risk factor for causing hepatocellular carcinomas. Nonstructural protein 3 (NS3) of HCV has serine protease and RNA helicase domains, and is essential for the viral replication. Further, NS3 is also considered to be involved in the development of HCV-induced hepatocellular carcinomas. In this report, we focus on the function of NS3 protein, and propose a novel possible molecular mechanism which is thought to be related to the tumorigenesis caused by the persistent infection of HCV. We identified SRCAP (Snf2-related CBP activator protein) as a NS3 binding protein using yeast two-hybrid screening, and a co-immunoprecipitation assay demonstrated that NS3 can bind to SRCAP in mammalian cells. The results of a reporter gene assay using Hes-1 promoter which is known to be a target gene activated by Notch, indicate that NS3 and SRCAP cooperatively activate the Hes-1 promoter in Hep3B cells. In addition, we show in this report that also p400, which is known as a protein closely resembling SRCAP, would be targeted by NS3. NS3 exhibited binding activity also to the 1449–1808 region of p400 by a co-immunoprecipitation assay, and further the activation of the Notch-mediated transcription of Hes-1 promoter by NS3 decreased significantly by the combined silencing of SRCAP and p400 mRNA using short hairpin RNA. These results suggest that the HCV NS3 protein is involved in the activation of the Notch-signaling pathway through the targeting to both SRCAP and p400.
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Affiliation(s)
- Atsushi Iwai
- Department of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan
| | - Tsutomu Takegami
- Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa, Japan
- * E-mail:
| | - Takuya Shiozaki
- Department of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan
| | - Tadaaki Miyazaki
- Department of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan
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Baumann C, Viveiros MM, De La Fuente R. Loss of maternal ATRX results in centromere instability and aneuploidy in the mammalian oocyte and pre-implantation embryo. PLoS Genet 2010; 6:e1001137. [PMID: 20885787 PMCID: PMC2944790 DOI: 10.1371/journal.pgen.1001137] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 08/24/2010] [Indexed: 01/10/2023] Open
Abstract
The α-thalassemia/mental retardation X-linked protein (ATRX) is a chromatin-remodeling factor known to regulate DNA methylation at repetitive sequences of the human genome. We have previously demonstrated that ATRX binds to pericentric heterochromatin domains in mouse oocytes at the metaphase II stage where it is involved in mediating chromosome alignment at the meiotic spindle. However, the role of ATRX in the functional differentiation of chromatin structure during meiosis is not known. To test ATRX function in the germ line, we developed an oocyte-specific transgenic RNAi knockdown mouse model. Our results demonstrate that ATRX is required for heterochromatin formation and maintenance of chromosome stability during meiosis. During prophase I arrest, ATRX is necessary to recruit the transcriptional regulator DAXX (death domain associated protein) to pericentric heterochromatin. At the metaphase II stage, transgenic ATRX-RNAi oocytes exhibit abnormal chromosome morphology associated with reduced phosphorylation of histone 3 at serine 10 as well as chromosome segregation defects leading to aneuploidy and severely reduced fertility. Notably, a large proportion of ATRX-depleted oocytes and 1-cell stage embryos exhibit chromosome fragments and centromeric DNA–containing micronuclei. Our results provide novel evidence indicating that ATRX is required for centromere stability and the epigenetic control of heterochromatin function during meiosis and the transition to the first mitosis. The transmission of an abnormal chromosome complement from the gametes to the early embryo, a condition called aneuploidy, is a major cause of congenital birth defects and pregnancy loss. Human embryos are particularly susceptible to aneuploidy, which in the majority of cases is the result of abnormal meiosis in the female gamete. However, the molecular mechanisms involved in the onset of aneuploidy in mammalian oocytes are not fully understood. We show here that, the α-thalassemia/mental retardation X-linked protein (ATRX) is essential for the maintenance of chromosome stability during female meiosis. ATRX is required to recruit the transcriptional regulator DAXX to pericentric heterochromatin at prophase I of meiosis. Notably, lack of ATRX function at the metaphase II stage interferes with the establishment of chromatin modifications associated with chromosome condensation leading to segregation defects, chromosome fragmentation, and severely reduced fertility. Our results provide direct evidence for a role of ATRX in the regulation of pericentric heterochromatin structure and function in mammalian oocytes and have important implications for our understanding of the epigenetic factors contributing to the onset of aneuploidy in the female gamete.
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Affiliation(s)
- Claudia Baumann
- Female Germ Cell Biology Group, Department of Clinical Studies, University of Pennsylvania, Kennett Square, Pennsylvania, United States of America
| | - Maria M. Viveiros
- Department of Animal Biology, Center for Animal Transgenesis and Germ Cell Research, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, United States of America
| | - Rabindranath De La Fuente
- Female Germ Cell Biology Group, Department of Clinical Studies, University of Pennsylvania, Kennett Square, Pennsylvania, United States of America
- * E-mail:
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Flores-Alvarado LJ, Ramirez-Garcia SA, Núñez-Reveles NY. [The metabolic and molecular bases of Cockayne syndrome]. Rev Invest Clin 2010; 62:480-490. [PMID: 21416736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cockayne is a segmental progeroid syndrome that has autosomal recessive inheritance pattern. It is mainly characterized by Intrauterine growth retardation, severe postnatal growth deficiency, cachectic dwarfism, microcephaly, wizened face, sensorineural hearing loss, cataracts, dental caries, cardiac arrhythmias, hypertension, atherosclerosis, proteinuria, micropenis, renal failure, skeletal abnormalities, skin photosensitivity, decreased subcutaneous adipose tissue, cerebral atrophy, dementia, basal ganglia calcifications, ataxia and apraxia. It has a complex phenotype given by genetic heterogeneity. There are five gene responsible for this syndrome: CSA, CSB, XPB, XPD and XPG, in which various mutations have been found. The biochemical effect of these mutations includes dysfunctional protein of the repair system for oxidative damage to DNA, the complex coupled to transcription and the nucleotide excision repair system. Considering the role played for these proteins and its effects on clinical phenotype when they are deficient, we suggest that these genes might be candidates for analyzing susceptibility to common chronic degenerative diseases related to oxidative stress and aging.
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Cohet N, Stewart KM, Mudhasani R, Asirvatham AJ, Mallappa C, Imbalzano KM, Weaver VM, Imbalzano AN, Nickerson JA. SWI/SNF chromatin remodeling enzyme ATPases promote cell proliferation in normal mammary epithelial cells. J Cell Physiol 2010; 223:667-78. [PMID: 20333683 DOI: 10.1002/jcp.22072] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The ATPase subunits of the SWI/SNF chromatin remodeling enzymes, Brahma (BRM) and Brahma-related gene 1 (BRG1), can induce cell cycle arrest in BRM and BRG1 deficient tumor cell lines, and mice heterozygous for Brg1 are pre-disposed to breast tumors, implicating loss of BRG1 as a mechanism for unregulated cell proliferation. To test the hypothesis that loss of BRG1 can contribute to breast cancer, we utilized RNA interference to reduce the amounts of BRM or BRG1 protein in the nonmalignant mammary epithelial cell line, MCF-10A. When grown in reconstituted basement membrane (rBM), these cells develop into acini that resemble the lobes of normal breast tissue. Contrary to expectations, knockdown of either BRM or BRG1 resulted in an inhibition of cell proliferation in monolayer cultures. This inhibition was strikingly enhanced in three-dimensional rBM culture, although some BRM-depleted cells were later able to resume proliferation. Cells did not arrest in any specific stage of the cell cycle; instead, the cell cycle length increased by approximately 50%. Thus, SWI/SNF ATPases promote cell cycle progression in nonmalignant mammary epithelial cells.
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Affiliation(s)
- Nathalie Cohet
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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Schwab RA, Blackford AN, Niedzwiedz W. ATR activation and replication fork restart are defective in FANCM-deficient cells. EMBO J 2010; 29:806-18. [PMID: 20057355 PMCID: PMC2829160 DOI: 10.1038/emboj.2009.385] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 11/24/2009] [Indexed: 01/20/2023] Open
Abstract
Fanconi anaemia is a chromosomal instability disorder associated with cancer predisposition and bone marrow failure. Among the 13 identified FA gene products only one, the DNA translocase FANCM, has homologues in lower organisms, suggesting a conserved function in DNA metabolism. However, a precise role for FANCM in DNA repair remains elusive. Here, we show a novel function for FANCM that is distinct from its role in the FA pathway: promoting replication fork restart and simultaneously limiting the accumulation of RPA-ssDNA. We show that in DT40 cells this process is controlled by ATR and PLK1, and that in the absence of FANCM, stalled replication forks are unable to resume DNA synthesis and genome duplication is ensured by excess origin firing. Unexpectedly, we also uncover an early role for FANCM in ATR-mediated checkpoint signalling by promoting chromatin retention of TopBP1. Failure to retain TopBP1 on chromatin impacts on the ability of ATR to phosphorylate downstream molecular targets, including Chk1 and SMC1. Our data therefore indicate a fundamental role for FANCM in the maintenance of genome integrity during S phase.
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Affiliation(s)
- Rebekka A Schwab
- Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Andrew N Blackford
- Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Wojciech Niedzwiedz
- Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw, Poland
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Kernohan KD, Jiang Y, Tremblay DC, Bonvissuto AC, Eubanks JH, Mann MRW, Bérubé NG. ATRX partners with cohesin and MeCP2 and contributes to developmental silencing of imprinted genes in the brain. Dev Cell 2010; 18:191-202. [PMID: 20159591 DOI: 10.1016/j.devcel.2009.12.017] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 10/12/2009] [Accepted: 12/17/2009] [Indexed: 11/27/2022]
Abstract
Human developmental disorders caused by chromatin dysfunction often display overlapping clinical manifestations, such as cognitive deficits, but the underlying molecular links are poorly defined. Here, we show that ATRX, MeCP2, and cohesin, chromatin regulators implicated in ATR-X, RTT, and CdLS syndromes, respectively, interact in the brain and colocalize at the H19 imprinting control region (ICR) with preferential binding on the maternal allele. Importantly, we show that ATRX loss of function alters enrichment of cohesin, CTCF, and histone modifications at the H19 ICR, without affecting DNA methylation on the paternal allele. ATRX also affects cohesin, CTCF, and MeCP2 occupancy within the Gtl2/Dlk1 imprinted domain. Finally, we show that loss of ATRX interferes with the postnatal silencing of the maternal H19 gene along with a larger network of imprinted genes. We propose that ATRX, cohesin, and MeCP2 cooperate to silence a subset of imprinted genes in the postnatal mouse brain.
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Affiliation(s)
- Kristin D Kernohan
- Department of Paediatrics, 800 Commissioners Road East, London, ON N6C 2V5, Canada
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37
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Abstract
DNA cytosine methylation is an important epigenetic mechanism that is involved in transcriptional silencing of developmental genes. Several molecular pathways have been described that interfere with Pol II initiation, but at individual genes the molecular mechanism of repression remains uncertain. Here, we study the molecular mechanism of transcriptional regulation at Hox genes in dependence of the epigenetic regulator Lsh that controls CpG methylation at selected Hox genes. Wild type cells show a nucleosomal deprived region around the transcriptional start site at methylated Hox genes and mediate gene silencing via Pol II stalling. Hypomethylation in Lsh-/- cells is associated with efficient transcriptional elongation and splicing, in part mediated by the chromodomain protein Chd1. Dynamic modulation of DNA methylation in Lsh-/- and wild type cells demonstrates that catalytically active DNA methyltransferase activity is required for Pol II stalling. Taken together, the data suggests that DNA methylation can be compatible with Pol II binding at selected genes and Pol II stalling can act as alternate mechanism to explain transcriptional silencing associated with DNA methylation.
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Affiliation(s)
- Yongguang Tao
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, Maryland, United States of America
| | - Sichuan Xi
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, Maryland, United States of America
| | - Victorino Briones
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, Maryland, United States of America
| | - Kathrin Muegge
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, Maryland, United States of America
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38
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Abstract
DNA-dependent adenosine triphosphatases (ATPases) participate in a broad range of biological processes including transcription, DNA repair, and chromatin dynamics. Mutations in the HepA-related protein (HARP) ATPase are responsible for Schimke immuno-osseous dysplasia (SIOD), but the function of the protein is unknown. We found that HARP is an ATP-dependent annealing helicase that rewinds single-stranded DNA bubbles that are stably bound by replication protein A. Other related ATPases, including the DNA translocase Rad54, did not exhibit annealing helicase activity. Analysis of mutant HARP proteins suggests that SIOD is caused by a deficiency in annealing helicase activity. Moreover, the pleiotropy of HARP mutations is consistent with the function of HARP as an annealing helicase that acts throughout the genome to oppose the action of DNA-unwinding activities in the nucleus.
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Affiliation(s)
- Timur Yusufzai
- Section of Molecular Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0347 USA
| | - James T. Kadonaga
- Section of Molecular Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0347 USA
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Fan T, Schmidtmann A, Xi S, Briones V, Zhu H, Suh HC, Gooya J, Keller JR, Xu H, Roayaei J, Anver M, Ruscetti S, Muegge K. DNA hypomethylation caused by Lsh deletion promotes erythroleukemia development. Epigenetics 2008; 3:134-42. [PMID: 18487951 PMCID: PMC3113485 DOI: 10.4161/epi.3.3.6252] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hematopoietic malignancies are frequently associated with DNA hypomethylation but the molecular mechanisms involved in tumor formation remain poorly understood. Here we report that mice lacking Lsh develop leukemia associated with DNA hypomethylation and oncogene activation. Lsh is a member of the SNF2 chromatin remodeling family and is required for de novo methylation of genomic DNA. Mice that received Lsh deficient hematopoietic progenitors showed severe impairment of hematopoiesis, suggesting that Lsh is necessary for normal hematopoiesis. A subset of mice developed erythroleukemia, a tumor that does not spontaneously occur in mice. Tumor tissues were CpG hypomethylated and showed a modest elevation of the transcription factor PU.1, an oncogene that is crucial for Friend virus induced erythroleukemia. Analysis of Lsh(-/-) hematopoietic progenitors revealed widespread DNA hypomethylation at repetitive sequences and hypomethylation at specific retroviral elements within the PU.1 gene. Wild type cells showed Lsh and Dnmt3b binding at the retroviral elements located within the PU.1 gene. On the other hand, Lsh deficient cells had no detectable Dnmt3b association suggesting that Lsh is necessary for recruitment of Dnmt3b to its target. Furthermore, Lsh(-/-) hematopoietic precursors showed impaired suppression of retroviral elements in the PU.1 gene, an increase of PU.1 transcripts and protein levels. Thus DNA hypomethylation caused by Lsh depletion is linked to transcriptional upregulation of retroviral elements and oncogenes such as PU.1 which in turn may promote the development of erythroleukemia in mice.
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Affiliation(s)
- Tao Fan
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Anja Schmidtmann
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Sichuan Xi
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Victorino Briones
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Heming Zhu
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Hyung Chan Suh
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - John Gooya
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Jonathan R. Keller
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Hong Xu
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Jean Roayaei
- Computer and Statistical Services; National Cancer Institute; Frederick, Maryland USA
| | - Miriam Anver
- Pathology/Histotechnology Laboratory; SAIC Frederick; National Cancer Institute; Frederick, Maryland USA
| | - Sandra Ruscetti
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
| | - Kathrin Muegge
- Laboratory of Cancer Prevention; SAIC-FCRDC; Basic Research Program; National Cancer Institute; Frederick, Maryland USA
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Udaka T, Okamoto N, Aramaki M, Torii C, Kosaki R, Hosokai N, Hayakawa T, Takahata N, Takahashi T, Kosaki K. An Alu retrotransposition-mediated deletion of CHD7 in a patient with CHARGE syndrome. Am J Med Genet A 2007; 143A:721-6. [PMID: 17334995 DOI: 10.1002/ajmg.a.31441] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
CHD7 mutations account for about 60-65% among more than 200 CHARGE syndrome cases. When rare whole gene deletion cases associated with chromosomal abnormalities are excluded, all mutations of CHD7 reported to date have been point mutations and small deletions and insertions, rather than exonic deletions. To test whether exonic deletions represent a common pathogenic mechanism, we assessed exon copy number by using a recently developed method, the multiplex PCR/liquid chromatography assay (MP/LC). Multiple exons were amplified using unlabeled primers, then separated by ion-pair reversed-phase high-performance liquid chromatography, and quantitated by fluorescence detection using a post-column intercalation dye under the premise that the relative peak intensities for each target directly reflect exon copy number. By using MP/LC, we identified one CHARGE syndrome patient who had a de novo deletion encompassing exons 8-12 among 13 classic CHARGE patients in whom screening by denaturing high-performance liquid chromatography (DHPLC) failed to identify point mutations and small insertions/deletions in CHD7. This is the first CHARGE patient who was documented to have exonic deletion of CHD7. The deletion closely recapitulated the Alu-mediated inactivation of the human CMP-N-acetylneuraminic acid hydroxylase gene (CMP-Neu5Ac hydroxylase), which is regarded as a novel molecular mechanism in the evolution from non-human primates to humans. As demonstrated in this study, MP/LC is a promising method for characterizing exonic deletions, which are largely left unexamined in most routine mutation analysis.
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Affiliation(s)
- Toru Udaka
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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So S, Adachi N, Koyama H. Absence of p53 enhances growth defects and etoposide sensitivity of human cells lacking the Bloom syndrome helicase BLM. DNA Cell Biol 2007; 26:517-25. [PMID: 17630856 DOI: 10.1089/dna.2007.0578] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The Bloom syndrome helicase BLM and the tumor-suppressor protein p53 play important roles in preserving genome integrity. Here, we knock out the genes for BLM and p53 in a human pre-B-cell line, Nalm-6. We show that p53 plays an important role in cell proliferation, but not apoptosis, when BLM is absent. Intriguingly, despite the apoptotic function of p53, BLM(/)TP53(/) cells were more sensitive than either single mutant to etoposide, an anticancer agent that poisons DNA topoisomerase II. Our results suggest a direct, BLM-independent role for p53 in etoposide-induced, topoisomerase II-mediated DNA damage in human cells.
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Affiliation(s)
- Sairei So
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
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Abstract
Polycomb-mediated repression and DNA methylation are important epigenetic mechanisms of gene silencing. Recent evidence suggests a functional link between the polycomb repressive complex (PRC) and Dnmts in cancer cells. Here we provide evidence that Lsh, a regulator of DNA methylation, is also involved in normal control of PRC-mediated silencing during embryogenesis. We demonstrate that Lsh, a SNF2 homolog, can associate with some Hox genes and regulates Dnmt3b binding, DNA methylation, and silencing of Hox genes during development. Moreover, Lsh can associate with PRC1 components and influence PRC-mediated histone modifications. Thus Lsh is part of a physiological feedback loop that reinforces DNA methylation and silencing of PRC targets.
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Affiliation(s)
- Sichuan Xi
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
| | - Heming Zhu
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
| | - Hong Xu
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
| | - Anja Schmidtmann
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
| | - Theresa M. Geiman
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
| | - Kathrin Muegge
- Laboratory of Cancer Prevention, SAIC-Frederick, National Cancer Institute, Frederick, MD 21702-1201
- *To whom correspondence should be addressed. E-mail:
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Rao VA, Conti C, Guirouilh-Barbat J, Nakamura A, Miao ZH, Davies SL, Saccá B, Hickson ID, Bensimon A, Pommier Y. Endogenous γ-H2AX-ATM-Chk2 Checkpoint Activation in Bloom's Syndrome Helicase–Deficient Cells Is Related to DNA Replication Arrested Forks. Mol Cancer Res 2007; 5:713-24. [PMID: 17634426 DOI: 10.1158/1541-7786.mcr-07-0028] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Bloom syndrome helicase (BLM) is critical for genomic stability. A defect in BLM activity results in the cancer-predisposing Bloom syndrome (BS). Here, we report that BLM-deficient cell lines and primary fibroblasts display an endogenously activated DNA double-strand break checkpoint response with prominent levels of phosphorylated histone H2AX (gamma-H2AX), Chk2 (p(T68)Chk2), and ATM (p(S1981)ATM) colocalizing in nuclear foci. Interestingly, the mitotic fraction of gamma-H2AX foci did not seem to be higher in BLM-deficient cells, indicating that these lesions form transiently during interphase. Pulse labeling with iododeoxyuridine and immunofluorescence microscopy showed the colocalization of gamma-H2AX, ATM, and Chk2 together with replication foci. Those foci costained for Rad51, indicating homologous recombination at these replication sites. We therefore analyzed replication in BS cells using a single molecule approach on combed DNA fibers. In addition to a higher frequency of replication fork barriers, BS cells displayed a reduced average fork velocity and global reduction of interorigin distances indicative of an elevated frequency of origin firing. Because BS is one of the most penetrant cancer-predisposing hereditary diseases, it is likely that the lack of BLM engages the cells in a situation similar to precancerous tissues with replication stress. To our knowledge, this is the first report of high ATM-Chk2 kinase activation and its linkage to replication defects in a BS model.
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Affiliation(s)
- V Ashutosh Rao
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, U.S. Department of Health and Human Services, Bethesda, Maryland, USA
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Sillibourne JE, Delaval B, Redick S, Sinha M, Doxsey SJ. Chromatin remodeling proteins interact with pericentrin to regulate centrosome integrity. Mol Biol Cell 2007; 18:3667-80. [PMID: 17626165 PMCID: PMC1951766 DOI: 10.1091/mbc.e06-07-0604] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pericentrin is an integral centrosomal component that anchors regulatory and structural molecules to centrosomes. In a yeast two-hybrid screen with pericentrin we identified chromodomain helicase DNA-binding protein 4 (CHD4/Mi2beta). CHD4 is part of the multiprotein nucleosome remodeling deacetylase (NuRD) complex. We show that many NuRD components interacted with pericentrin by coimmunoprecipitation and that they localized to centrosomes and midbodies. Overexpression of the pericentrin-binding domain of CHD4 or another family member (CHD3) dissociated pericentrin from centrosomes. Depletion of CHD3, but not CHD4, by RNA interference dissociated pericentrin and gamma-tubulin from centrosomes. Microtubule nucleation/organization, cell morphology, and nuclear centration were disrupted in CHD3-depleted cells. Spindles were disorganized, the majority showing a prometaphase-like configuration. Time-lapse imaging revealed mitotic failure before chromosome segregation and cytokinesis failure. We conclude that pericentrin forms complexes with CHD3 and CHD4, but a distinct CHD3-pericentrin complex is required for centrosomal anchoring of pericentrin/gamma-tubulin and for centrosome integrity.
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Chan KL, North PS, Hickson ID. BLM is required for faithful chromosome segregation and its localization defines a class of ultrafine anaphase bridges. EMBO J 2007; 26:3397-409. [PMID: 17599064 PMCID: PMC1933408 DOI: 10.1038/sj.emboj.7601777] [Citation(s) in RCA: 323] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 05/31/2007] [Indexed: 11/08/2022] Open
Abstract
Mutations in BLM cause Bloom's syndrome, a disorder associated with cancer predisposition and chromosomal instability. We investigated whether BLM plays a role in ensuring the faithful chromosome segregation in human cells. We show that BLM-defective cells display a higher frequency of anaphase bridges and lagging chromatin than do isogenic corrected derivatives that eptopically express the BLM protein. In normal cells undergoing mitosis, BLM protein localizes to anaphase bridges, where it colocalizes with its cellular partners, topoisomerase IIIalpha and hRMI1 (BLAP75). Using BLM staining as a marker, we have identified a class of ultrafine DNA bridges in anaphase that are surprisingly prevalent in the anaphase population of normal human cells. These so-called BLM-DNA bridges, which also stain for the PICH protein, frequently link centromeric loci, and are present at an elevated frequency in cells lacking BLM. On the basis of these results, we propose that sister-chromatid disjunction is often incomplete in human cells even after the onset of anaphase. We present a model for the action of BLM in ensuring complete sister chromatid decatenation in anaphase.
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Affiliation(s)
- Kok-Lung Chan
- Cancer Research UK Laboratories, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Phillip S North
- Cancer Research UK Laboratories, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Ian D Hickson
- Cancer Research UK Laboratories, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
- Cancer Research UK Oxford Cancer Centre, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK. Tel.: +44 1865 222 417; Fax: +44 1865 222 431; E-mail:
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Liu QZ, Jiang GF, He Y, Wang XR, Zhou JW, Zhuang ZX. Arsenite-induced alterations in Ku70-deficient cells: a model to study genotoxic effects. J Toxicol Environ Health A 2007; 70:938-46. [PMID: 17479409 DOI: 10.1080/15287390701290253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
As one of three subunits of DNA-dependent protein kinase (DNA-PK), Ku70 protein plays an important role in repair of DNA double-strand breaks (DNA DSB). To further understand the functions of Ku70 protein and the mechanisms underlying arsenite-induced genotoxic effects, the effects of Ku70 deficiency were examined. The Ku70-deficient cell line HLFK and null vector cell line HLFC were established after recombinant plasmid of Ku70 gene antisense RNA and null pEGFP-C1 vector were transferred into human embryo lung fibroblasts (HLF) cells. Experiments were undertaken to detect DNA DSB damage by neutral single-cell gel electrophoresis assay (SCGE), chromosomal alterations by micronucleus test, and cell cycle progression by flow cytometry in HLFC and HLFK cells treated with control, 1, 2.5, 5, or 10 microM sodium arsenite for 2, 4, or 24 h, respectively. Western blot analysis results showed that Ku70 protein content in HLFK cells decreased to 38% of those in HLFC cells. The median lethal concentrations (LC50) of sodium arsenite to HLFC and HLFK cells for 24 h were 27.38 microM and 21.80 microM, respectively. Results of neutral SCGE assay showed that there were concentration-dependent increases in tail length of DNA DSB, in percent of cells with DNA DSB tails, and in severity of DNA DSB damage in HLFK and HLFC cells. The increases in these indices in HLFK cells were significantly higher than those found in HLFC cells exposed to similar amounts of metal. The ability of DNA DSB to repair in HLFK cells was less than that seen in HLFC cells. Sodium arsenite produced concentration-dependent elevation in micronuclei and abnormal nuclei formation. The Ku70-deficiency enhanced the susceptibility to chromosomal alterations induced by sodium arsenite. Low concentrations of sodium arsenite induced cell arrest at G1; however, at high concentrations of metal this G1 arrest effect disappeared. These results suggested that Ku70 protein plays an important role in repair of DNA DSB damage and for maintainance of genome stability.
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Affiliation(s)
- Qi-Zhan Liu
- Department of Molecular Cell Biology and Toxicology, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
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Gunawardena RW, Fox SR, Siddiqui H, Knudsen ES. SWI/SNF activity is required for the repression of deoxyribonucleotide triphosphate metabolic enzymes via the recruitment of mSin3B. J Biol Chem 2007; 282:20116-23. [PMID: 17510060 DOI: 10.1074/jbc.m701406200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The SWI/SNF chromatin remodeling complex plays a critical role in the coordination of gene expression with physiological stimuli. The synthetic enzymes ribonucleotide reductase, dihydrofolate reductase, and thymidylate synthase are coordinately regulated to ensure appropriate deoxyribonucleotide triphosphate levels. Particularly, these enzymes are actively repressed as cells exit the cell cycle through the action of E2F transcription factors and the retinoblastoma tumor suppressor/p107/p130 family of pocket proteins. This process is found to be highly dependent on SWI/SNF activity as cells deficient in BRG-1 and Brm subunits fail to repress these genes with activation of pocket proteins, and this deficit in repression can be complemented, via the ectopic expression of BRG-1. The failure to repress transcription does not involve a blockade in the association of E2F or pocket proteins p107 and p130 with promoter elements. Rather, the deficit in repression is due to a failure to mediate histone deacetylation of ribonucleotide reductase, dihydrofolate reductase, and thymidylate synthase promoters in the absence of SWI/SNF activity. The basis for this is found to be a failure to recruit mSin3B and histone deacetylase proteins to promoters. Thus, the coordinate repression of deoxyribonucleotide triphosphate metabolic enzymes is dependent on the action of SWI/SNF in facilitating the assembly of repressor complexes at the promoter.
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Affiliation(s)
- Ranjaka W Gunawardena
- Department of Cell and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0521, USA
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48
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Peiró-Chova L, Estruch F. Specific defects in different transcription complexes compensate for the requirement of the negative cofactor 2 repressor in Saccharomyces cerevisiae. Genetics 2007; 176:125-38. [PMID: 17339209 PMCID: PMC1893036 DOI: 10.1534/genetics.106.066829] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 02/12/2007] [Indexed: 11/18/2022] Open
Abstract
Negative cofactor 2 (NC2) has been described as an essential and evolutionarily conserved transcriptional repressor, although in vitro and in vivo experiments suggest that it can function as both a positive and a negative effector of transcription. NC2 operates by interacting with the core promoter and components of the basal transcription machinery, like the TATA-binding protein (TBP). In this work, we have isolated mutants that suppress the growth defect caused by the depletion of NC2. We have identified mutations affecting components of three different complexes involved in the control of basal transcription: the mediator, TFIIH, and RNA pol II itself. Mutations in RNA pol II include both overexpression of truncated forms of the two largest subunits (Rpb1 and Rpb2) and reduced levels of these proteins. Suppression of NC2 depletion was also observed by reducing the amounts of the mediator essential components Nut2 and Med7, as well as by deleting any of the nonessential mediator components, except Med2, Med3, and Gal11 subunits. Interestingly, the Med2/Med3/Gal11 triad forms a submodule within the mediator tail. Our results support the existence of different components within the basic transcription complexes that antagonistically interact with the NC2 repressor and suggest that the correct balance between the activities of specific positive and negative components is essential for cell growth.
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Affiliation(s)
- Lorena Peiró-Chova
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Valencia, 46100 Burjassot, Spain
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Chandramouli A, Shi J, Feng Y, Holubec H, Shanas RM, Bhattacharyya AK, Zheng W, Nelson MA. Haploinsufficiency of the cdc2l gene contributes to skin cancer development in mice. Carcinogenesis 2007; 28:2028-35. [PMID: 17389615 DOI: 10.1093/carcin/bgm066] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Cdc2L gene encodes for the cyclin-dependent kinase 11 (CDK11) protein. Loss of one allele of Cdc2L and reduced CDK11 expression has been observed in several cancers, implicating its association with carcinogenesis. To directly investigate the role of CDK11 in carcinogenesis, we first generated cdc2l haploinsufficient mice by gene trap technology and then studied the susceptibility of these gene-trapped (cdc2l(GT)) mice to chemical-mediated skin carcinogenesis in the 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced two-stage skin carcinogenesis model. Wild-type and cdc2l(GT) mice were subjected to a single topical application of initiation by DMBA and promotion twice a week for 19 weeks with TPA. At 19 weeks, 70% of the cdc2l(GT) mice and 60% of the cdc2l+/+ mice developed benign papillomas. However, there was an overall 3-fold increase in the average number of tumors per mouse observed in cdc2l(GT) mice as compared with cdc2l+/+ mice. There was also an increased frequency of larger papillomas in cdc2l(GT) mice. By using the polymerase chain reaction-restriction fragment length polymorphism assay, we found A to T transversion mutations at the 61st codon of H-ras gene in the papilloma tissue of both cdc2l(GT) mice and cdc2l+/+ mice. Ki-67 staining revealed increased proliferation in the papillomas of cdc2l(GT) (77.75%) as compared with cdc2l+/+ (30.84%) tumors. These studies are the first to show that loss of one allele of cdc2l gene, encoding CDK11, facilitates DMBA/TPA-induced skin carcinogenesis in vivo.
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Affiliation(s)
- Anupama Chandramouli
- Department of Pathology, Arizona Cancer Center, University of Arizona, 1501 North Campbell Avenue, LSN 550, Tucson, AZ, USA
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50
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Kohzaki M, Hatanaka A, Sonoda E, Yamazoe M, Kikuchi K, Vu Trung N, Szüts D, Sale JE, Shinagawa H, Watanabe M, Takeda S. Cooperative roles of vertebrate Fbh1 and Blm DNA helicases in avoidance of crossovers during recombination initiated by replication fork collapse. Mol Cell Biol 2007; 27:2812-20. [PMID: 17283053 PMCID: PMC1899948 DOI: 10.1128/mcb.02043-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fbh1 (F-box DNA helicase 1) orthologues are conserved from Schizosaccharomyces pombe to chickens and humans. Here, we report the disruption of the FBH1 gene in DT40 cells. Although the yeast fbh1 mutant shows an increase in sensitivity to DNA damaging agents, FBH1(-)(/)(-) DT40 clones show no prominent sensitivity, suggesting that the loss of FBH1 might be compensated by other genes. However, FBH1(-)(/)(-) cells exhibit increases in both sister chromatid exchange and the formation of radial structures between homologous chromosomes without showing a defect in homologous recombination. This phenotype is reminiscent of BLM(-)(/)(-) cells and suggests that Fbh1 may be involved in preventing extensive strand exchange during homologous recombination. In addition, disruption of RAD54, a major homologous recombination factor in FBH1(-)(/)(-) cells, results in a marked increase in chromosome-type breaks (breaks on both sister chromatids at the same place) following replication fork arrest. Further, FBH1BLM cells showed additive increases in both sister chromatid exchange and the formation of radial chromosomes. These data suggest that Fbh1 acts in parallel with Bloom helicase to control recombination-mediated double-strand-break repair at replication blocks and to reduce the frequency of crossover.
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Affiliation(s)
- Masaoki Kohzaki
- Department of Radiation Genetics, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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