1
|
Yang C, He Y, Wang Y, McKinnon PJ, Shahani V, Miller DD, Pfeffer LM. Next-generation bromodomain inhibitors of the SWI/SNF complex enhance DNA damage and cell death in glioblastoma. J Cell Mol Med 2023; 27:2770-2781. [PMID: 37593885 PMCID: PMC10494295 DOI: 10.1111/jcmm.17907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/19/2023] Open
Abstract
Glioblastoma (GBM) is an aggressive brain cancer with a poor prognosis. While surgical resection is the primary treatment, adjuvant temozolomide (TMZ) chemotherapy and radiotherapy only provide slight improvement in disease course and outcome. Unfortunately, most treated patients experience recurrence of highly aggressive, therapy-resistant tumours and eventually succumb to the disease. To increase chemosensitivity and overcome therapy resistance, we have modified the chemical structure of the PFI-3 bromodomain inhibitor of the BRG1 and BRM catalytic subunits of the SWI/SNF chromatin remodelling complex. Our modifications resulted in compounds that sensitized GBM to the DNA alkylating agent TMZ and the radiomimetic bleomycin. We screened these chemical analogues using a cell death ELISA with GBM cell lines and a cellular thermal shift assay using epitope tagged BRG1 or BRM bromodomains expressed in GBM cells. An active analogue, IV-129, was then identified and further modified, resulting in new generation of bromodomain inhibitors with distinct properties. IV-255 and IV-275 had higher bioactivity than IV-129, with IV-255 selectively binding to the bromodomain of BRG1 and not BRM, while IV-275 bound well to both BRG1 and BRM bromodomains. In contrast, IV-191 did not bind to either bromodomain or alter GBM chemosensitivity. Importantly, both IV-255 and IV-275 markedly increased the extent of DNA damage induced by TMZ and bleomycin as determined by nuclear γH2AX staining. Our results demonstrate that these next-generation inhibitors selectively bind to the bromodomains of catalytic subunits of the SWI/SNF complex and sensitize GBM to the anticancer effects of TMZ and bleomycin. This approach holds promise for improving the treatment of GBM.
Collapse
Affiliation(s)
- Chuanhe Yang
- Department of Pathology and Laboratory MedicineCollege of Medicine, University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Yali He
- Department of Pharmaceutical SciencesCollege of Pharmacy, University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Yinan Wang
- Department of Pathology and Laboratory MedicineCollege of Medicine, University of Tennessee Health Science CenterMemphisTennesseeUSA
| | | | - Vijay Shahani
- Recursion Pharmaceuticals IncTorontoOntarioM5V 2A2Canada
| | - Duane D. Miller
- Department of Pharmaceutical SciencesCollege of Pharmacy, University of Tennessee Health Science CenterMemphisTennesseeUSA
- The Center for Cancer ResearchUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Lawrence M. Pfeffer
- Department of Pathology and Laboratory MedicineCollege of Medicine, University of Tennessee Health Science CenterMemphisTennesseeUSA
- The Center for Cancer ResearchUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| |
Collapse
|
2
|
Araki O, Tsuda M, Omatsu M, Namikawa M, Sono M, Fukunaga Y, Masuda T, Yoshikawa T, Nagao M, Ogawa S, Masuo K, Goto N, Muta Y, Hiramatsu Y, Maruno T, Nakanishi Y, Koyasu S, Masui T, Hatano E, Saur D, Fukuda A, Seno H. Brg1 controls stemness and metastasis of pancreatic cancer through regulating hypoxia pathway. Oncogene 2023:10.1038/s41388-023-02716-4. [PMID: 37198398 DOI: 10.1038/s41388-023-02716-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. We previously reported that chromatin remodeler Brg1 is essential for acinar cell-derived PDAC formation in mice. However, the functional role of Brg1 in established PDAC and its metastasis remains unknown. Here, we investigated the importance of Brg1 for established PDAC by using a mouse model with a dual recombinase system. We discovered that Brg1 was a critical player for the cell survival and growth of spontaneously developed PDAC in mice. In addition, Brg1 was essential for metastasis of PDAC cells by inhibiting apoptosis in splenic injection and peritoneal dissemination models. Moreover, cancer stem-like property was compromised in PDAC cells by Brg1 ablation. Mechanistically, the hypoxia pathway was downregulated in Brg1-deleted mouse PDAC and BRG1-low human PDAC. Brg1 was essential for HIF-1α to bind to its target genes to augment the hypoxia pathway, which was important for PDAC cells to maintain their stem-like properties and to metastasize to the liver. Human PDAC cells with high BRG1 expression were more susceptible to BRG1 suppression. In conclusion, Brg1 plays a critical role for cell survival, stem-like property and metastasis of PDAC through the regulation of hypoxia pathway, and thus could be a novel therapeutic target for PDAC.
Collapse
Affiliation(s)
- Osamu Araki
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mayuki Omatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mio Namikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Makoto Sono
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuichi Fukunaga
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomonori Masuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takaaki Yoshikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Munemasa Nagao
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Masuo
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Norihiro Goto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Muta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuki Nakanishi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sho Koyasu
- Departments of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toshihiko Masui
- Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Etsuro Hatano
- Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Dieter Saur
- Department of Internal Medicine II, Klinikum rechts der Isar, Technische Universität München, München, Germany
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| |
Collapse
|
3
|
Abedini A, Landry DA, Macaulay AD, Vaishnav H, Parbhakar A, Ibrahim D, Salehi R, Maranda V, Macdonald E, Vanderhyden BC. SWI/SNF chromatin remodeling subunit Smarca4/BRG1 is essential for female fertility†. Biol Reprod 2023; 108:279-291. [PMID: 36440965 PMCID: PMC9930400 DOI: 10.1093/biolre/ioac209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 07/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Mammalian folliculogenesis is a complex process that involves the regulation of chromatin structure for gene expression and oocyte meiotic resumption. The SWI/SNF complex is a chromatin remodeler using either Brahma-regulated gene 1 (BRG1) or BRM (encoded by Smarca4 and Smarca2, respectively) as its catalytic subunit. SMARCA4 loss of expression is associated with a rare type of ovarian cancer; however, its function during folliculogenesis remains poorly understood. In this study, we describe the phenotype of BRG1 mutant mice to better understand its role in female fertility. Although no tumor emerged from BRG1 mutant mice, conditional depletion of Brg1 in the granulosa cells (GCs) of Brg1fl/fl;Amhr2-Cre mice caused sterility, whereas conditional depletion of Brg1 in the oocytes of Brg1fl/fl;Gdf9-Cre mice resulted in subfertility. Recovery of cumulus-oocyte complexes after natural mating or superovulation showed no significant difference in the Brg1fl/fl;Amhr2-Cre mutant mice and significantly fewer oocytes in the Brg1fl/fl;Gdf9-Cre mutant mice compared with controls, which may account for the subfertility. Interestingly, the evaluation of oocyte developmental competence by in vitro culture of retrieved two-cell embryos indicated that oocytes originating from the Brg1fl/fl;Amhr2-Cre mice did not reach the blastocyst stage and had higher rates of mitotic defects, including micronuclei. Together, these results indicate that BRG1 plays an important role in female fertility by regulating granulosa and oocyte functions during follicle growth and is needed for the acquisition of oocyte developmental competence.
Collapse
Affiliation(s)
- Atefeh Abedini
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David A Landry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Angus D Macaulay
- Chronic Diseases Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Het Vaishnav
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Ashna Parbhakar
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Dalia Ibrahim
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Reza Salehi
- Chronic Diseases Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Vincent Maranda
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Elizabeth Macdonald
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Barbara C Vanderhyden
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| |
Collapse
|
4
|
Nguyen VT, Tessema M, Weissman BE. The SWI/SNF Complex: A Frequently Mutated Chromatin Remodeling Complex in Cancer. Cancer Treat Res 2023; 190:211-244. [PMID: 38113003 DOI: 10.1007/978-3-031-45654-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The switch/sucrose non-fermenting (SWI/SNF) chromatin remodeling complex is a global regulator of gene expression known to maintain nucleosome-depleted regions at active enhancers and promoters. The mammalian SWI/SNF protein subunits are encoded by 29 genes and 11-15 subunits including an ATPase domain of either SMARCA4 (BRG1) or SMARCA2 (BRM) are assembled into a complex. Based on the distinct subunits, SWI/SNF are grouped into 3 major types (subfamilies): the canonical BRG1/BRM-associated factor (BAF/cBAF), polybromo-associated BAF (PBAF), and non-canonical BAF (GBAF/ncBAF). Pan-cancer genome sequencing studies have shown that nearly 25% of all cancers bear mutations in subunits of the SWI/SNF complex, many of which are loss of function (LOF) mutations, suggesting a tumor suppressor role. Inactivation of SWI/SNF complex subunits causes widespread epigenetic dysfunction, including increased dependence on antagonistic components such as polycomb repressor complexes (PRC1/2) and altered enhancer regulation, likely promoting an oncogenic state leading to cancer. Despite the prevalence of mutations, most SWI/SNF-mutant cancers lack targeted therapeutic strategies. Defining the dependencies created by LOF mutations in SWI/SNF subunits will identify better targets for these cancers.
Collapse
Affiliation(s)
- Vinh The Nguyen
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Mathewos Tessema
- Lung Cancer Program, Lovelace Biomedical Research Institute, Albuquerque, NM, USA
| | - Bernard Ellis Weissman
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
| |
Collapse
|
5
|
Schiavoni F, Zuazua-Villar P, Roumeliotis TI, Benstead-Hume G, Pardo M, Pearl FMG, Choudhary JS, Downs JA. Aneuploidy tolerance caused by BRG1 loss allows chromosome gains and recovery of fitness. Nat Commun 2022; 13:1731. [PMID: 35365638 PMCID: PMC8975814 DOI: 10.1038/s41467-022-29420-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 03/16/2022] [Indexed: 11/17/2022] Open
Abstract
Aneuploidy results in decreased cellular fitness in many species and model systems. However, aneuploidy is commonly found in cancer cells and often correlates with aggressive growth, suggesting that the impact of aneuploidy on cellular fitness is context dependent. The BRG1 (SMARCA4) subunit of the SWI/SNF chromatin remodelling complex is frequently lost in cancer. Here, we use a chromosomally stable cell line to test the effect of BRG1 loss on the evolution of aneuploidy. BRG1 deletion leads to an initial loss of fitness in this cell line that improves over time. Notably, we find increased tolerance to aneuploidy immediately upon loss of BRG1, and the fitness recovery over time correlates with chromosome gain. These data show that BRG1 loss creates an environment where karyotype changes can be explored without a fitness penalty. At least in some genetic backgrounds, therefore, BRG1 loss can affect the progression of tumourigenesis through tolerance of aneuploidy.
Collapse
Affiliation(s)
- Federica Schiavoni
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | - Pedro Zuazua-Villar
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | - Theodoros I Roumeliotis
- Functional Proteomics Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | - Graeme Benstead-Hume
- Functional Proteomics Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
- Bioinformatics Group, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
| | - Mercedes Pardo
- Functional Proteomics Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | - Frances M G Pearl
- Bioinformatics Group, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
| | - Jyoti S Choudhary
- Functional Proteomics Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | - Jessica A Downs
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK.
| |
Collapse
|
6
|
Yang C, Wang Y, Sims MM, He Y, Miller DD, Pfeffer LM. Targeting the Bromodomain of BRG-1/BRM Subunit of the SWI/SNF Complex Increases the Anticancer Activity of Temozolomide in Glioblastoma. Pharmaceuticals (Basel) 2021; 14:ph14090904. [PMID: 34577604 PMCID: PMC8467157 DOI: 10.3390/ph14090904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 11/16/2022] Open
Abstract
Glioblastoma (GBM) is a deadly and incurable brain cancer with limited therapeutic options. PFI-3 is a small-molecule bromodomain (BRD) inhibitor of the BRM/BRG1 subunits of the SWI/SNF chromatin remodeling complex. The objective of this study is to determine the efficacy of PFI-3 as a potential GBM therapy. We report that PFI-3 binds to these BRDs when expressed in GBM cells. PFI-3 markedly enhanced the antiproliferative and cell death-inducing effects of temozolomide (TMZ) in TMZ-sensitive GBM cells as well as overcame the chemoresistance of highly TMZ-resistant GBM cells. PFI-3 also altered gene expression in GBM and enhanced the basal and interferon-induced expression of a subset of interferon-responsive genes. Besides the effects of PFI-3 on GBM cells in vitro, we found that PFI-3 markedly potentiated the anticancer effect of TMZ in an intracranial GBM animal model, resulting in a marked increase in survival of animals bearing GBM tumors. Taken together, we identified the BRG1 and BRM subunits of SWI/SNF as novel targets in GBM and revealed the therapeutic potential of applying small molecule inhibitors of SWI/SNF to improve the clinical outcome in GBM using standard-of-care chemotherapy.
Collapse
Affiliation(s)
- Chuanhe Yang
- Department of Pathology and Laboratory Medicine, Center for Cancer Research, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (C.Y.); (Y.W.); (M.M.S.)
| | - Yinan Wang
- Department of Pathology and Laboratory Medicine, Center for Cancer Research, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (C.Y.); (Y.W.); (M.M.S.)
| | - Michelle M. Sims
- Department of Pathology and Laboratory Medicine, Center for Cancer Research, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (C.Y.); (Y.W.); (M.M.S.)
| | - Yali He
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (Y.H.); (D.D.M.)
| | - Duane D. Miller
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (Y.H.); (D.D.M.)
| | - Lawrence M. Pfeffer
- Department of Pathology and Laboratory Medicine, Center for Cancer Research, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (C.Y.); (Y.W.); (M.M.S.)
- Correspondence:
| |
Collapse
|
7
|
Wang Y, Yang CH, Schultz AP, Sims MM, Miller DD, Pfeffer LM. Brahma-Related Gene-1 (BRG1) promotes the malignant phenotype of glioblastoma cells. J Cell Mol Med 2021; 25:2956-2966. [PMID: 33528916 PMCID: PMC7957270 DOI: 10.1111/jcmm.16330] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 01/16/2023] Open
Abstract
Glioblastoma multiforme (GBM) is an aggressive malignant brain tumour that is resistant to existing therapeutics. Identifying signalling pathways deregulated in GBM that can be targeted therapeutically is critical to improve the present dismal prognosis for GBM patients. In this report, we have identified that the BRG1 (Brahma‐Related Gene‐1) catalytic subunit of the SWI/SNF chromatin remodelling complex promotes the malignant phenotype of GBM cells. We found that BRG1 is ubiquitously expressed in tumour tissue from GBM patients, and high BRG1 expression levels are localized to specific brain tumour regions. Knockout (KO) of BRG1 by CRISPR‐Cas9 gene editing had minimal effects on GBM cell proliferation, but significantly inhibited GBM cell migration and invasion. BRG1‐KO also sensitized GBM cells to the anti‐proliferative effects of the anti‐cancer agent temozolomide (TMZ), which is used to treat GBM patients in the clinic, and selectively altered STAT3 tyrosine phosphorylation and gene expression. These results demonstrate that BRG‐1 promotes invasion and migration, and decreases chemotherapy sensitivity, indicating that it functions in an oncogenic manner in GBM cells. Taken together, our findings suggest that targeting BRG1 in GBM may have therapeutic benefit in the treatment of this deadly form of brain cancer.
Collapse
Affiliation(s)
- Yinan Wang
- Department of Pathology and Laboratory Medicine (College of Medicine), and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Chuan He Yang
- Department of Pathology and Laboratory Medicine (College of Medicine), and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Andrew P Schultz
- Department of Pathology and Laboratory Medicine (College of Medicine), and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michelle M Sims
- Department of Pathology and Laboratory Medicine (College of Medicine), and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Duane D Miller
- Department of Pharmaceutical Sciences (College of Pharmacy), University of Tennessee Health Science Center, Memphis, TN, USA
| | - Lawrence M Pfeffer
- Department of Pathology and Laboratory Medicine (College of Medicine), and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
8
|
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] [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.
Collapse
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
| |
Collapse
|
9
|
Kurashima K, Kashiwagi H, Shimomura I, Suzuki A, Takeshita F, Mazevet M, Harata M, Yamashita T, Yamamoto Y, Kohno T, Shiotani B. SMARCA4 deficiency-associated heterochromatin induces intrinsic DNA replication stress and susceptibility to ATR inhibition in lung adenocarcinoma. NAR Cancer 2020; 2:zcaa005. [PMID: 34316685 PMCID: PMC8210217 DOI: 10.1093/narcan/zcaa005] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 03/28/2020] [Accepted: 04/16/2020] [Indexed: 12/31/2022] Open
Abstract
The SWI/SNF chromatin remodeling complex regulates transcription through the control of chromatin structure and is increasingly thought to play an important role in human cancer. Lung adenocarcinoma (LADC) patients frequently harbor mutations in SMARCA4, a core component of this multisubunit complex. Most of these mutations are loss-of-function mutations, which disrupt critical functions in the regulation of chromatin architecture and can cause DNA replication stress. This study reports that LADC cells deficient in SMARCA4 showed increased DNA replication stress and greater sensitivity to the ATR inhibitor (ATRi) in vitro and in vivo. Mechanistically, loss of SMARCA4 increased heterochromatin formation, resulting in stalled forks, a typical DNA replication stress. In the absence of SMARCA4, severe ATRi-induced single-stranded DNA, which caused replication catastrophe, was generated on nascent DNA near the reversed forks around heterochromatin in an Mre11-dependent manner. Thus, loss of SMARCA4 confers susceptibility to ATRi, both by increasing heterochromatin-associated replication stress and by allowing Mre11 to destabilize reversed forks. These two mechanisms synergistically increase susceptibility of SMARCA4-deficient LADC cells to ATRi. These results provide a preclinical basis for assessing SMARCA4 defects as a biomarker of ATRi efficacy.
Collapse
Affiliation(s)
- Kiminori Kurashima
- Division of Cellular Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Hideto Kashiwagi
- Division of Cellular Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Iwao Shimomura
- Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba-shi, Chiba 260-8670, Japan
| | - Ayako Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, Chiba 277-8562, Japan
| | - Fumitaka Takeshita
- Department of Functional Analysis, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Marianne Mazevet
- Division of Cellular Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Masahiko Harata
- Graduate School of Agricultural Science, Tohoku University, Sendai-shi, Miyagi 980-0845, Japan
| | - Takayuki Yamashita
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi-shi, Gunma 371-8512, Japan
| | - Yusuke Yamamoto
- Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Takashi Kohno
- Division of Genome Biology, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Bunsyo Shiotani
- To whom correspondence should be addressed. Tel: +81 3 3547 5201 (Ext. 3681); Fax: +81 3 3543 9305;
| |
Collapse
|
10
|
Zhou Q, Meng QR, Meng TG, He QL, Zhao ZH, Li QN, Lei WL, Liu SZ, Schatten H, Wang ZB, Sun QY. Deletion of BAF250a affects oocyte epigenetic modifications and embryonic development. Mol Reprod Dev 2020; 87:550-564. [PMID: 32215983 DOI: 10.1002/mrd.23339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/11/2020] [Indexed: 11/10/2022]
Abstract
BRG1-associated factor 250a (BAF250a) is a component of the SWI/SNF adenosine triphosphate-dependent chromatin remodeling complex, which has been shown to control chromatin structure and transcription. BAF250a was reported to be a key component of the gene regulatory machinery in embryonic stem cells controlling self-renewal, differentiation, and cell lineage decisions. Here we constructed Baf250aF/F ;Gdf9-cre (Baf250aCKO ) mice to specifically delete BAF250a in oocytes to investigate the role of maternal BAF250a in female germ cells and embryo development. Our results showed that BAF250a deletion did not affect folliculogenesis, ovulation, and fertilization, but it caused late embryonic death. RNA sequencing analysis showed that the expression of genes involved in cell proliferation and differentiation, tissue morphogenesis, histone modification, and nucleosome remodeling were perturbed in Baf250aCKO MII oocytes. We showed that covalent histone modifications such as H3K27me3 and H3K27ac were also significantly affected in oocytes, which may reduce oocyte quality and lead to birth defects. In addition, the DNA methylation level of Igf2r, Snrpn, and Peg3 differentially methylated regions was decreased in Baf250aCKO oocytes. Quantitative real-time polymerase chain reaction analysis showed that the relative messenger RNA (mRNA) expression levels of Igf2r and Snrpn were significantly increased. The mRNA expression level of Dnmt1, Dnmt3a, Dnmt3l, and Uhrf1 was decreased, and the protein expression in these genes was also reduced, which might be the cause for impaired imprinting establishment. In conclusion, our results demonstrate that BAF250a plays an important role in oocyte transcription regulation, epigenetic modifications, and embryo development.
Collapse
Affiliation(s)
- Qian Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qing-Ren Meng
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Tie-Gang Meng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qi-Long He
- Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Zheng-Hui Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qian-Nan Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Wen-Long Lei
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Shu-Zhen Liu
- Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
11
|
Orlando KA, Nguyen V, Raab JR, Walhart T, Weissman BE. Remodeling the cancer epigenome: mutations in the SWI/SNF complex offer new therapeutic opportunities. Expert Rev Anticancer Ther 2019; 19:375-391. [PMID: 30986130 DOI: 10.1080/14737140.2019.1605905] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Cancer genome sequencing studies have discovered mutations in members of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin-remodeling complex in nearly 25% of human cancers. The SWI/SNF complex, first discovered in S. cerevisiae, shows strong conservation from yeast to Drosophila to mammals, contains approximately 10-12 subunits and regulates nucleosome positioning through the energy generated by its ATPase subunits. The unexpected finding of frequent mutations in the complex has fueled studies to identify the mechanisms that drive tumor development and the accompanying therapeutic vulnerabilities. Areas covered: In the review, we focus upon the potential roles different SWI/SNF subunit mutations play in human oncogenesis, their common and unique mechanisms of transformation and the potential for translating these mechanisms into targeted therapies for SWI/SNF-mutant tumors. Expert opinion: We currently have limited insights into how mutations in different SWI/SNF subunits drive the development of human tumors. Because the SWI/SNF complex participates in a broad range of normal cellular functions, defining specific oncogenic pathways has proved difficult. In addition, therapeutic options for SWI/SNF-mutant cancers have mainly evolved from high-throughput screens of cell lines with mutations in different subunits. Future studies should follow a more coherent plan to pinpoint common vulnerabilities among these tumors.
Collapse
Affiliation(s)
- Krystal A Orlando
- a Department of Pathology and Laboratory Medicine , University of North Carolina , Chapel Hill , NC , USA
| | - Vinh Nguyen
- b Curriculum in Toxicology and Environmental Medicine , University of North Carolina , Chapel Hill , NC , USA
| | - Jesse R Raab
- c Department of Genetics , University of North Carolina , Chapel Hill , NC , USA
| | - Tara Walhart
- d Lineberger Comprehensive Cancer Center , University of North Carolina , Chapel Hill , NC , USA
| | - Bernard E Weissman
- a Department of Pathology and Laboratory Medicine , University of North Carolina , Chapel Hill , NC , USA.,b Curriculum in Toxicology and Environmental Medicine , University of North Carolina , Chapel Hill , NC , USA.,d Lineberger Comprehensive Cancer Center , University of North Carolina , Chapel Hill , NC , USA
| |
Collapse
|
12
|
Ribeiro-Silva C, Vermeulen W, Lans H. SWI/SNF: Complex complexes in genome stability and cancer. DNA Repair (Amst) 2019; 77:87-95. [PMID: 30897376 DOI: 10.1016/j.dnarep.2019.03.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 01/25/2023]
Abstract
SWI/SNF complexes are among the most studied ATP-dependent chromatin remodeling complexes, mostly due to their critical role in coordinating chromatin architecture and gene expression. Mutations in genes encoding SWI/SNF subunits are frequently observed in a large variety of human cancers, suggesting that one or more of the multiple SWI/SNF functions protect against tumorigenesis. Chromatin remodeling is an integral component of the DNA damage response (DDR), which safeguards against DNA damage-induced genome instability and tumorigenesis by removing DNA damage through interconnected DNA repair and signaling pathways. SWI/SNF has been implicated in facilitating repair of double-strand breaks, by non-homologous end-joining as well as homologous recombination, and repair of helix-distorting DNA damage by nucleotide excision repair. Here, we review current knowledge on SWI/SNF activity in the DDR and discuss the potential of exploiting DDR-related vulnerabilities due to SWI/SNF dysfunction for precision cancer therapy.
Collapse
Affiliation(s)
- Cristina Ribeiro-Silva
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
| | - Wim Vermeulen
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands.
| | - Hannes Lans
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands.
| |
Collapse
|
13
|
Ganguly D, Sims M, Cai C, Fan M, Pfeffer LM. Chromatin Remodeling Factor BRG1 Regulates Stemness and Chemosensitivity of Glioma Initiating Cells. Stem Cells 2018; 36:1804-1815. [PMID: 30171737 DOI: 10.1002/stem.2909] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/23/2018] [Accepted: 08/18/2018] [Indexed: 12/13/2022]
Abstract
Glioblastoma multiforme (GBM) is a highly aggressive and malignant brain tumor that is refractory to existing therapeutic regimens, which reflects the presence of stem-like cells, termed glioma-initiating cells (GICs). The complex interactions between different signaling pathways and epigenetic regulation of key genes may be critical in the maintaining GICs in their stem-like state. Although several signaling pathways have been identified as being dysregulated in GBM, the prognosis of GBM patients remains miserable despite improvements in targeted therapies. In this report, we identified that BRG1, the catalytic subunit of the SWI/SNF chromatin remodeling complex, plays a fundamental role in maintaining GICs in their stem-like state. In addition, we identified a novel mechanism by which BRG1 regulates glycolysis genes critical for GICs. BRG1 downregulates the expression of TXNIP, a negative regulator of glycolysis. BRG1 knockdown also triggered the STAT3 pathway, which led to TXNIP activation. We further identified that TXNIP is an STAT3-regulated gene. Moreover, BRG1 suppressed the expression of interferon-stimulated genes, which are negatively regulated by STAT3 and regulate tumorigenesis. We further demonstrate that BRG1 plays a critical role in the drug resistance of GICs and in GIC-induced tumorigenesis. By genetic and pharmacological means, we found that inhibiting BRG1 can sensitize GICs to chemotherapeutic drugs, temozolomide and carmustine. Our studies suggest that BRG1 may be a novel therapeutic target in GBM. The identification of the critical role that BRG1 plays in GIC stemness and chemosensitivity will inform the development of better targeted therapies in GBM and possibly other cancers. Stem Cells 2018;36:1806-12.
Collapse
Affiliation(s)
- Debolina Ganguly
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Michelle Sims
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Chun Cai
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Meiyun Fan
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Lawrence M Pfeffer
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| |
Collapse
|
14
|
Kouprina N, Petrov N, Molina O, Liskovykh M, Pesenti E, Ohzeki JI, Masumoto H, Earnshaw WC, Larionov V. Human Artificial Chromosome with Regulated Centromere: A Tool for Genome and Cancer Studies. ACS Synth Biol 2018; 7:1974-1989. [PMID: 30075081 PMCID: PMC6154217 DOI: 10.1021/acssynbio.8b00230] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Since their description in the late 1990s, Human Artificial Chromosomes (HACs) bearing functional kinetochores have been considered as promising systems for gene delivery and expression. More recently a HAC assembled from a synthetic alphoid DNA array has been exploited in studies of centromeric chromatin and in assessing the impact of different epigenetic modifications on kinetochore structure and function in human cells. This HAC was termed the alphoidtetO-HAC, as the synthetic monomers each contained a tetO sequence in place of the CENP-B box that can be targeted specifically with tetR-fusion proteins. Studies in which the kinetochore chromatin of the alphoidtetO-HAC was specifically modified, revealed that heterochromatin is incompatible with centromere function and that centromeric transcription is important for centromere assembly and maintenance. In addition, the alphoidtetO-HAC was modified to carry large gene inserts that are expressed in target cells under conditions that recapitulate the physiological regulation of endogenous loci. Importantly, the phenotypes arising from stable gene expression can be reversed when cells are "cured" of the HAC by inactivating its kinetochore in proliferating cell populations, a feature that provides a control for phenotypic changes attributed to expression of HAC-encoded genes. AlphoidtetO-HAC-based technology has also been used to develop new drug screening and assessment strategies to manipulate the CIN phenotype in cancer cells. In summary, the alphoidtetO-HAC is proving to be a versatile tool for studying human chromosome transactions and structure as well as for genome and cancer studies.
Collapse
Affiliation(s)
- Natalay Kouprina
- Developmental
Therapeutics Branch, National Cancer Institute,
NIH, Bethesda, Maryland 20892, United
States,E-mail: . Tel: +1-240-760-7325
| | - Nikolai Petrov
- Developmental
Therapeutics Branch, National Cancer Institute,
NIH, Bethesda, Maryland 20892, United
States
| | - Oscar Molina
- Josep
Carreras Leukaemia Research Institute, School of Medicine, University
of Barcelona, Casanova 143, 08036 Barcelona, Spain
| | - Mikhail Liskovykh
- Developmental
Therapeutics Branch, National Cancer Institute,
NIH, Bethesda, Maryland 20892, United
States
| | - Elisa Pesenti
- Wellcome
Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland
| | - Jun-ichirou Ohzeki
- Laboratory
of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818d Japan
| | - Hiroshi Masumoto
- Laboratory
of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818d Japan,E-mail: . Tel: +81-438-52-395
| | - William C. Earnshaw
- Wellcome
Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland,E-mail: . Tel: +44-(0)131-650-7101
| | - Vladimir Larionov
- Developmental
Therapeutics Branch, National Cancer Institute,
NIH, Bethesda, Maryland 20892, United
States,E-mail: . Tel: +1-240-760-7325
| |
Collapse
|
15
|
Bögershausen N, Wollnik B. Mutational Landscapes and Phenotypic Spectrum of SWI/SNF-Related Intellectual Disability Disorders. Front Mol Neurosci 2018; 11:252. [PMID: 30123105 PMCID: PMC6085491 DOI: 10.3389/fnmol.2018.00252] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 12/29/2022] Open
Abstract
Mutations in genes that encode proteins of the SWI/SNF complex, called BAF complex in mammals, cause a spectrum of disorders that ranges from syndromic intellectual disability to Coffin-Siris syndrome (CSS) to Nicolaides-Baraitser syndrome (NCBRS). While NCBRS is known to be a recognizable and restricted phenotype, caused by missense mutations in SMARCA2, the term CSS has been used lately for a more heterogeneous group of phenotypes that are caused by mutations in either of the genes ARID1B, ARID1A, ARID2, SMARCA4, SMARCB1, SMARCE1, SOX11, or DPF2. In this review, we summarize the current knowledge on the phenotypic traits and molecular causes of the above named conditions, consider the question whether a clinical distinction of the phenotypes is still adequate, and suggest the term "SWI/SNF-related intellectual disability disorders" (SSRIDDs). We will also outline important features to identify the ARID1B-related phenotype in the absence of classic CSS features, and discuss distinctive and overlapping features of the SSRIDD subtypes. Moreover, we will briefly review the function of the SWI/SNF complex in development and describe the mutational landscapes of the genes involved in SSRIDD.
Collapse
Affiliation(s)
- Nina Bögershausen
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
16
|
Fukuda K, Okuda A, Yusa K, Shinkai Y. A CRISPR knockout screen identifies SETDB1-target retroelement silencing factors in embryonic stem cells. Genome Res 2018; 28:846-858. [PMID: 29728365 PMCID: PMC5991520 DOI: 10.1101/gr.227280.117] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 04/26/2018] [Indexed: 12/16/2022]
Abstract
In mouse embryonic stem cells (mESCs), the expression of provirus and endogenous retroelements is epigenetically repressed. Although many cellular factors involved in retroelement silencing have been identified, the complete molecular mechanism remains elusive. In this study, we performed a genome-wide CRISPR screen to advance our understanding of retroelement silencing in mESCs. The Moloney murine leukemia virus (MLV)–based retroviral vector MSCV-GFP, which is repressed by the SETDB1/TRIM28 pathway in mESCs, was used as a reporter provirus, and we identified more than 80 genes involved in this process. In particular, ATF7IP and the BAF complex components are linked with the repression of most of the SETDB1 targets. We characterized two factors, MORC2A and RESF1, of which RESF1 is a novel molecule in retroelement silencing. Although both factors are recruited to repress provirus, their roles in repression are different. MORC2A appears to function dependent on repressive epigenetic modifications, while RESF1 regulates repressive epigenetic modifications associated with SETDB1. Our genome-wide CRISPR screen cataloged genes which function at different levels in silencing of SETDB1-target retroelements and provides a useful resource for further molecular studies.
Collapse
Affiliation(s)
- Kei Fukuda
- Cellular Memory Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiko Okuda
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane Hidaka Saitama 350-1241, Japan
| | - Kosuke Yusa
- Wellcome Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Yoichi Shinkai
- Cellular Memory Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| |
Collapse
|
17
|
Pesenti E, Kouprina N, Liskovykh M, Aurich-Costa J, Larionov V, Masumoto H, Earnshaw WC, Molina O. Generation of a Synthetic Human Chromosome with Two Centromeric Domains for Advanced Epigenetic Engineering Studies. ACS Synth Biol 2018; 7:1116-1130. [PMID: 29565577 PMCID: PMC5951608 DOI: 10.1021/acssynbio.8b00018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
It is generally accepted that chromatin containing the histone H3 variant CENP-A is an epigenetic mark maintaining centromere identity. However, the pathways leading to the formation and maintenance of centromere chromatin remain poorly characterized due to difficulties of analysis of centromeric repeats in native chromosomes. To address this problem, in our previous studies we generated a human artificial chromosome (HAC) whose centromere contains a synthetic alpha-satellite (alphoid) DNA array containing the tetracycline operator, the alphoidtetO-HAC. The presence of tetO sequences allows the specific targeting of the centromeric region in the HAC with different chromatin modifiers fused to the tetracycline repressor. The alphoidtetO-HAC has been extensively used to investigate protein interactions within the kinetochore and to define the epigenetic signature of centromeric chromatin to maintain a functional kinetochore. In this study, we developed a novel synthetic HAC containing two alphoid DNA arrays with different targeting sequences, tetO, lacO and gal4, the alphoidhybrid-HAC. This new HAC can be used for detailed epigenetic engineering studies because its kinetochore can be simultaneously or independently targeted by different chromatin modifiers and other fusion proteins.
Collapse
Affiliation(s)
- Elisa Pesenti
- Wellcome
Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3QR, United
Kingdom
| | - Natalay Kouprina
- Genome
Structure and Function Group, Developmental Therapeutics Branch, National
Cancer Institute, National Institutes of
Health, Bethesda, Maryland 20892, United States
| | - Mikhail Liskovykh
- Genome
Structure and Function Group, Developmental Therapeutics Branch, National
Cancer Institute, National Institutes of
Health, Bethesda, Maryland 20892, United States
| | - Joan Aurich-Costa
- Research
and Development, Cellay Inc., Cambridge, Massachusetts 02139, United States
| | - Vladimir Larionov
- Genome
Structure and Function Group, Developmental Therapeutics Branch, National
Cancer Institute, National Institutes of
Health, Bethesda, Maryland 20892, United States
| | - Hiroshi Masumoto
- Laboratory
of Cell Engineering, Department of Frontier Research, Kazusa DNA Research Institute, Kisazaru 292-0818, Japan
| | - William C. Earnshaw
- Wellcome
Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3QR, United
Kingdom,E-mail: ; tel: +34 93-557-2810
| | - Oscar Molina
- Wellcome
Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3QR, United
Kingdom,Josep
Carreras Leukaemia Research Institute, School of Medicine, University of Barcelona, Casanova 143, 08036 Barcelona, Spain,E-mail: ; tel: +44-(0)131-650-7101
| |
Collapse
|
18
|
Savas S, Skardasi G. The SWI/SNF complex subunit genes: Their functions, variations, and links to risk and survival outcomes in human cancers. Crit Rev Oncol Hematol 2018; 123:114-131. [PMID: 29482773 DOI: 10.1016/j.critrevonc.2018.01.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/24/2017] [Accepted: 01/17/2018] [Indexed: 02/06/2023] Open
Abstract
SWI/SNF is a multiprotein complex essential for regulation of eukaryotic gene expression. In this article, we review the function and characteristics of this complex and its subunits in cancer-related phenotypes. We also present and discuss the publically available survival analysis data for TCGA patient cohorts, revealing novel relationships between the expression levels of the SWI/SNF subunit genes and patient survival times in several cancers. Overall, multiple lines of research point to a wide-spread role for the SWI/SNF complex genes in human cancer susceptibility and patient survival times. Examples include the mutations in ARID1A with cancer-driving effects, associations of tumor SWI/SNF gene expression levels and patient survival times, and two BRM promoter region polymorphisms linked to risk or patient outcomes in multiple human cancers. These findings should motivate comprehensive studies in order to fully dissect these relationships and verify the potential clinical utility of the SWI/SNF genes in controlling cancer.
Collapse
Affiliation(s)
- Sevtap Savas
- Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, NL, Canada; Discipline of Oncology, Faculty of Medicine, Memorial University, St. John's, NL, Canada.
| | - Georgia Skardasi
- Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, NL, Canada
| |
Collapse
|
19
|
Comprehensive assessment of the expression of the SWI/SNF complex defines two distinct prognostic subtypes of ovarian clear cell carcinoma. Oncotarget 2018; 7:54758-54770. [PMID: 27340867 PMCID: PMC5342379 DOI: 10.18632/oncotarget.10181] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 06/01/2016] [Indexed: 12/18/2022] Open
Abstract
Somatic mutations in the ARID1A tumor-suppressor gene have been frequently identified in ovarian clear cell carcinoma (CCC) cases. BAF250a encoded by ARID1A is a member of the SWI/SNF complex, but the expression and mutation status of other SWI/SNF subunits have not been explored. The current study aimed to elucidate the biological and clinical significance of the SWI/SNF complex subunits, by assessing the expression and mutation status of SWI/SNF subunits, and distinct genomic aberrations associated with their expression. Of 82 CCC specimens, 38 samples presented no BAF250a expression, and 50 samples exhibited the loss of at least one subunit of the SWI/SNF complex. Cases which lack at least one SWI/SNF complex component exhibited significantly more advanced stages, faster growth and stronger nuclear atypia compared with SWI/SNF-positive samples (p<0.05). Although BAF250a expression is not related to poor prognosis, the group presenting the loss of at least one SWI/SNF complex subunit exhibited significantly shorter overall and progression-free survivals (p<0.05). A multivariate analysis suggested that the expression status of the SWI/SNF complex serves as an independent prognostic factor (p<0.005). The cases positive for all SWI/SNF subunits demonstrated significantly greater DNA copy number alterations, such as amplification at chromosomes 8q.24.3 and 20q.13.2-20q.13.33 (including ZNF217) and deletion at chromosomes 13q12.11-13q14.3 (including RB1), 17p13.2-17p13.1 (including TP53) and 19p13.2-19p13.12. In conclusion, the CCCs exhibiting the loss of one or multiple SWI/SNF complex subunits demonstrated aggressive behaviors and poor prognosis, whereas the CCCs with positive expression for all SWI/SNF components presented more copy number alterations and a favorable prognosis.
Collapse
|
20
|
Thompson LL, Jeusset LMP, Lepage CC, McManus KJ. Evolving Therapeutic Strategies to Exploit Chromosome Instability in Cancer. Cancers (Basel) 2017; 9:cancers9110151. [PMID: 29104272 PMCID: PMC5704169 DOI: 10.3390/cancers9110151] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 12/12/2022] Open
Abstract
Cancer is a devastating disease that claims over 8 million lives each year. Understanding the molecular etiology of the disease is critical to identify and develop new therapeutic strategies and targets. Chromosome instability (CIN) is an abnormal phenotype, characterized by progressive numerical and/or structural chromosomal changes, which is observed in virtually all cancer types. CIN generates intratumoral heterogeneity, drives cancer development, and promotes metastatic progression, and thus, it is associated with highly aggressive, drug-resistant tumors and poor patient prognosis. As CIN is observed in both primary and metastatic lesions, innovative strategies that exploit CIN may offer therapeutic benefits and better outcomes for cancer patients. Unfortunately, exploiting CIN remains a significant challenge, as the aberrant mechanisms driving CIN and their causative roles in cancer have yet to be fully elucidated. The development and utilization of CIN-exploiting therapies is further complicated by the associated risks for off-target effects and secondary cancers. Accordingly, this review will assess the strengths and limitations of current CIN-exploiting therapies, and discuss emerging strategies designed to overcome these challenges to improve outcomes and survival for patients diagnosed with cancer.
Collapse
Affiliation(s)
- Laura L Thompson
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
- Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
| | - Lucile M-P Jeusset
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
- Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
| | - Chloe C Lepage
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
- Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
| | - Kirk J McManus
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
- Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
| |
Collapse
|
21
|
Nickerson JA, Wu Q, Imbalzano AN. Mammalian SWI/SNF Enzymes and the Epigenetics of Tumor Cell Metabolic Reprogramming. Front Oncol 2017; 7:49. [PMID: 28421159 PMCID: PMC5378717 DOI: 10.3389/fonc.2017.00049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/09/2017] [Indexed: 01/27/2023] Open
Abstract
Tumor cells reprogram their metabolism to survive and grow in a challenging microenvironment. Some of this reprogramming is performed by epigenetic mechanisms. Epigenetics is in turn affected by metabolism; chromatin modifying enzymes are dependent on substrates that are also key metabolic intermediates. We have shown that the chromatin remodeling enzyme Brahma-related gene 1 (BRG1), an epigenetic regulator, is necessary for rapid breast cancer cell proliferation. The mechanism for this requirement is the BRG1-dependent transcription of key lipogenic enzymes and regulators. Reduction in lipid synthesis lowers proliferation rates, which can be restored by palmitate supplementation. This work has established BRG1 as an attractive target for breast cancer therapy. Unlike genetic alterations, epigenetic mechanisms are reversible, promising gentler therapies without permanent off-target effects at distant sites.
Collapse
Affiliation(s)
- Jeffrey A Nickerson
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Qiong Wu
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
| | - Anthony N Imbalzano
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| |
Collapse
|
22
|
Tagal V, Wei S, Zhang W, Brekken RA, Posner BA, Peyton M, Girard L, Hwang T, Wheeler DA, Minna JD, White MA, Gazdar AF, Roth MG. SMARCA4-inactivating mutations increase sensitivity to Aurora kinase A inhibitor VX-680 in non-small cell lung cancers. Nat Commun 2017; 8:14098. [PMID: 28102363 PMCID: PMC5253647 DOI: 10.1038/ncomms14098] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/28/2016] [Indexed: 12/23/2022] Open
Abstract
Mutations in the SMARCA4/BRG1 gene resulting in complete loss of its protein (BRG1) occur frequently in non-small cell lung cancer (NSCLC) cells. Currently, no single therapeutic agent has been identified as synthetically lethal with SMARCA4/BRG1 loss. We identify AURKA activity as essential in NSCLC cells lacking SMARCA4/BRG1. In these cells, RNAi-mediated depletion or chemical inhibition of AURKA induces apoptosis and cell death in vitro and in xenograft mouse models. Disc large homologue-associated protein 5 (HURP/DLGAP5), required for AURKA-dependent, centrosome-independent mitotic spindle assembly is essential for the survival and proliferation of SMARCA4/BRG1 mutant but not of SMARCA4/BRG1 wild-type cells. AURKA inhibitors may provide a therapeutic strategy for biomarker-driven clinical studies to treat the NSCLCs harbouring SMARCA4/BRG1-inactivating mutations.
Collapse
Affiliation(s)
- Vural Tagal
- Department of Biochemistry, UT Southwestern, Dallas, Texas 75390, USA
| | - Shuguang Wei
- Department of Biochemistry, UT Southwestern, Dallas, Texas 75390, USA
| | - Wei Zhang
- Department of Pathology, UT Southwestern, Dallas, Texas 75390, USA
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
| | - Rolf A. Brekken
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
- Department of Pharmacology, UT Southwestern, Dallas, Texas 75390, USA
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
| | - Bruce A. Posner
- Department of Biochemistry, UT Southwestern, Dallas, Texas 75390, USA
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
| | - Michael Peyton
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
| | - Luc Girard
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
- Department of Pharmacology, UT Southwestern, Dallas, Texas 75390, USA
| | - TaeHyun Hwang
- Department of Clinical Sciences, UT Southwestern, Dallas, Texas 75390, USA
| | - David A. Wheeler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - John D. Minna
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
- Department of Pharmacology, UT Southwestern, Dallas, Texas 75390, USA
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
- Department of Medicine, UT Southwestern, Dallas, Texas 75390, USA
| | - Michael A. White
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
- Department of Cell Biology, UT Southwestern, Dallas, Texas 75390, USA
| | - Adi F. Gazdar
- Department of Pathology, UT Southwestern, Dallas, Texas 75390, USA
- Hamon Center for Therapeutic Oncology Research, UT Southwestern, Dallas, Texas 75390, USA
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
| | - Michael G. Roth
- Department of Biochemistry, UT Southwestern, Dallas, Texas 75390, USA
- Harold Simmons Comprehensive Cancer Center, UT Southwestern, Dallas, Texas 75390, USA
| |
Collapse
|
23
|
Roles of pRB in the Regulation of Nucleosome and Chromatin Structures. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5959721. [PMID: 28101510 PMCID: PMC5215604 DOI: 10.1155/2016/5959721] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/08/2016] [Indexed: 01/31/2023]
Abstract
Retinoblastoma protein (pRB) interacts with E2F and other protein factors to play a pivotal role in regulating the expression of target genes that induce cell cycle arrest, apoptosis, and differentiation. pRB controls the local promoter activity and has the ability to change the structure of nucleosomes and/or chromosomes via histone modification, epigenetic changes, chromatin remodeling, and chromosome organization. Functional inactivation of pRB perturbs these cellular events and causes dysregulated cell growth and chromosome instability, which are hallmarks of cancer cells. The role of pRB in regulation of nucleosome/chromatin structures has been shown to link to tumor suppression. This review focuses on the ability of pRB to control nucleosome/chromatin structures via physical interactions with histone modifiers and chromatin factors and describes cancer therapies based on targeting these protein factors.
Collapse
|
24
|
Aldiri I, Ajioka I, Xu B, Zhang J, Chen X, Benavente C, Finkelstein D, Johnson D, Akiyama J, Pennacchio LA, Dyer MA. Brg1 coordinates multiple processes during retinogenesis and is a tumor suppressor in retinoblastoma. Development 2016; 142:4092-106. [PMID: 26628093 PMCID: PMC4712833 DOI: 10.1242/dev.124800] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Retinal development requires precise temporal and spatial coordination of cell cycle exit, cell fate specification, cell migration and differentiation. When this process is disrupted, retinoblastoma, a developmental tumor of the retina, can form. Epigenetic modulators are central to precisely coordinating developmental events, and many epigenetic processes have been implicated in cancer. Studying epigenetic mechanisms in development is challenging because they often regulate multiple cellular processes; therefore, elucidating the primary molecular mechanisms involved can be difficult. Here we explore the role of Brg1 (Smarca4) in retinal development and retinoblastoma in mice using molecular and cellular approaches. Brg1 was found to regulate retinal size by controlling cell cycle length, cell cycle exit and cell survival during development. Brg1 was not required for cell fate specification but was required for photoreceptor differentiation and cell adhesion/polarity programs that contribute to proper retinal lamination during development. The combination of defective cell differentiation and lamination led to retinal degeneration in Brg1-deficient retinae. Despite the hypocellularity, premature cell cycle exit, increased cell death and extended cell cycle length, retinal progenitor cells persisted in Brg1-deficient retinae, making them more susceptible to retinoblastoma. ChIP-Seq analysis suggests that Brg1 might regulate gene expression through multiple mechanisms. Summary: The SWI/SNF protein Brg1 controls cell cycle length, cell cycle exit and cell survival, and is required for cell differentiation and retinal lamination, in the developing mouse retina.
Collapse
Affiliation(s)
- Issam Aldiri
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Itsuki Ajioka
- Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan
| | - Beisi Xu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jiakun Zhang
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Xiang Chen
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Claudia Benavente
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Dianna Johnson
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jennifer Akiyama
- Lawrence Berkeley National Laboratory, Genomics Division, Berkeley, CA 94701, USA Department of Energy, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Len A Pennacchio
- Lawrence Berkeley National Laboratory, Genomics Division, Berkeley, CA 94701, USA Department of Energy, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN 38163, USA Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| |
Collapse
|
25
|
Gurard-Levin ZA, Wilson LOW, Pancaldi V, Postel-Vinay S, Sousa FG, Reyes C, Marangoni E, Gentien D, Valencia A, Pommier Y, Cottu P, Almouzni G. Chromatin Regulators as a Guide for Cancer Treatment Choice. Mol Cancer Ther 2016; 15:1768-77. [PMID: 27196757 DOI: 10.1158/1535-7163.mct-15-1008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 04/26/2016] [Indexed: 12/22/2022]
Abstract
The limited capacity to predict a patient's response to distinct chemotherapeutic agents is a major hurdle in cancer management. The efficiency of a large fraction of current cancer therapeutics (radio- and chemotherapies) is influenced by chromatin structure. Reciprocally, alterations in chromatin organization may affect resistance mechanisms. Here, we explore how the misexpression of chromatin regulators-factors involved in the establishment and maintenance of functional chromatin domains-can inform about the extent of docetaxel response. We exploit Affymetrix and NanoString gene expression data for a set of chromatin regulators generated from breast cancer patient-derived xenograft models and patient samples treated with docetaxel. Random Forest classification reveals specific panels of chromatin regulators, including key components of the SWI/SNF chromatin remodeler, which readily distinguish docetaxel high-responders and poor-responders. Further exploration of SWI/SNF components in the comprehensive NCI-60 dataset reveals that the expression inversely correlates with docetaxel sensitivity. Finally, we show that loss of the SWI/SNF subunit BRG1 (SMARCA4) in a model cell line leads to enhanced docetaxel sensitivity. Altogether, our findings point toward chromatin regulators as biomarkers for drug response as well as therapeutic targets to sensitize patients toward docetaxel and combat drug resistance. Mol Cancer Ther; 15(7); 1768-77. ©2016 AACR.
Collapse
Affiliation(s)
- Zachary A Gurard-Levin
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, Paris, France. Sorbonne Universités, UPMC Universite Paris 06, CNRS, UMR3664, Paris, France.
| | - Laurence O W Wilson
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, Paris, France. Sorbonne Universités, UPMC Universite Paris 06, CNRS, UMR3664, Paris, France
| | - Vera Pancaldi
- Spanish National Cancer Research Centre (CNIO), c/Melchor Fernandez, Almagro, Madrid, Spain
| | - Sophie Postel-Vinay
- DITEP (Département d'Innovations Thérapeutiques et Essais Précoces), Gustave Roussy, France. Inserm Unit U981, Gustave Roussy, Villejuif, France. Université Paris Saclay, Université Paris-Sud, Faculté de Médicine, Le Kremlin Bicêtre, France
| | - Fabricio G Sousa
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland
| | - Cecile Reyes
- Institut Curie, PSL Research University, Translational Research Department, Genomics Platform, Paris, France
| | - Elisabetta Marangoni
- Institut Curie, PSL Research University, Translational Research Department, Genomics Platform, Paris, France
| | - David Gentien
- Institut Curie, PSL Research University, Translational Research Department, Genomics Platform, Paris, France
| | - Alfonso Valencia
- Spanish National Cancer Research Centre (CNIO), c/Melchor Fernandez, Almagro, Madrid, Spain
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland
| | - Paul Cottu
- Institut Curie, Medical Oncology, Paris, France
| | - Geneviève Almouzni
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, Paris, France. Sorbonne Universités, UPMC Universite Paris 06, CNRS, UMR3664, Paris, France.
| |
Collapse
|
26
|
SWI/SNF complexes are required for full activation of the DNA-damage response. Oncotarget 2015; 6:732-45. [PMID: 25544751 PMCID: PMC4359251 DOI: 10.18632/oncotarget.2715] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 11/09/2014] [Indexed: 01/09/2023] Open
Abstract
SWI/SNF complexes utilize BRG1 (also known as SMARCA4) or BRM (also known as SMARCA2) as alternative catalytic subunits with ATPase activity to remodel chromatin. These chromatin-remodeling complexes are required for mammalian development and are mutated in ~20% of all human primary tumors. Yet our knowledge of their tumor-suppressor mechanism is limited. To investigate the role of SWI/SNF complexes in the DNA-damage response (DDR), we used shRNAs to deplete BRG1 and BRM and then exposed these cells to a panel of 6 genotoxic agents. Compared to controls, the shRNA knockdown cells were hypersensitive to certain genotoxic agents that cause double-strand breaks (DSBs) associated with stalled/collapsed replication forks but not to ionizing radiation-induced DSBs that arise independently of DNA replication. These findings were supported by our analysis of DDR kinases, which demonstrated a more prominent role for SWI/SNF in the activation of the ATR-Chk1 pathway than the ATM-Chk2 pathway. Surprisingly, γH2AX induction was attenuated in shRNA knockdown cells exposed to a topoisomerase II inhibitor (etoposide) but not to other genotoxic agents including IR. However, this finding is compatible with recent studies linking SWI/SNF with TOP2A and TOP2BP1. Depletion of BRG1 and BRM did not result in genomic instability in a tumor-derived cell line but did result in nucleoplasmic bridges in normal human fibroblasts. Taken together, these results suggest that SWI/SNF tumor-suppressor activity involves a role in the DDR to attenuate replicative stress and genomic instability. These results may also help to inform the selection of chemotherapeutics for tumors deficient for SWI/SNF function.
Collapse
|
27
|
Brownlee PM, Meisenberg C, Downs JA. The SWI/SNF chromatin remodelling complex: Its role in maintaining genome stability and preventing tumourigenesis. DNA Repair (Amst) 2015; 32:127-133. [PMID: 25981841 DOI: 10.1016/j.dnarep.2015.04.023] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Genes encoding subunits of the two SWI/SNF chromatin remodelling complexes (BAF and PBAF) are mutated in almost 20% of all human cancers. In addition to a role in regulating transcription, recent work from our laboratory and others identified roles for both complexes in DNA damage responses and the maintenance of sister chromatid cohesion, which may have profound impacts on genome stability and contribute to its role as a tumour suppressor. Here, we review some of the transcription-independent functions of the SWI/SNF chromatin remodelling complex and discuss these in light of their potential relevance to tumourigenesis.
Collapse
Affiliation(s)
- Peter M Brownlee
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Cornelia Meisenberg
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Jessica A Downs
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
| |
Collapse
|
28
|
Benavente CA, Dyer MA. Genetics and epigenetics of human retinoblastoma. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2015; 10:547-62. [PMID: 25621664 DOI: 10.1146/annurev-pathol-012414-040259] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Retinoblastoma is a pediatric tumor of the developing retina from which the genetic basis for cancer development was first described. Inactivation of both copies of the RB1 gene is the predominant initiating genetic lesion in retinoblastoma and is rate limiting for tumorigenesis. Recent whole-genome sequencing of retinoblastoma uncovered a tumor that had no coding-region mutations or focal chromosomal lesions other than in the RB1 gene, shifting the paradigm in the field. The retinoblastoma genome can be very stable; therefore, epigenetic deregulation of tumor-promoting pathways is required for tumorigenesis. This review highlights the genetic and epigenetic changes in retinoblastoma that have been reported, with special emphasis on recent whole-genome sequencing and epigenetic analyses that have identified novel candidate genes as potential therapeutic targets.
Collapse
Affiliation(s)
- Claudia A Benavente
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105;
| | | |
Collapse
|
29
|
Stockman DL, Curry JL, Torres-Cabala CA, Watson IR, Siroy AE, Bassett RL, Zou L, Patel KP, Luthra R, Davies MA, Wargo JA, Routbort MA, Broaddus RR, Prieto VG, Lazar AJ, Tetzlaff MT. Use of clinical next-generation sequencing to identify melanomas harboringSMARCB1mutations. J Cutan Pathol 2015; 42:308-17. [DOI: 10.1111/cup.12481] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/01/2015] [Indexed: 12/26/2022]
Affiliation(s)
- David L. Stockman
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Jonathan L. Curry
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Carlos A. Torres-Cabala
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Ian R. Watson
- Department of Genomic Medicine; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Alan E. Siroy
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Roland L. Bassett
- Department of Biostatistics; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Lihua Zou
- The Eli and Edythe L. Broad Institute of Massachusetts; Institute of Technology and Harvard University; Cambridge Massachusetts USA
| | - Keyur P. Patel
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Rajyalakshmi Luthra
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Michael A. Davies
- Department of Melanoma Medical Oncology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Jennifer A. Wargo
- Department of Surgery; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Mark A. Routbort
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Russell R. Broaddus
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Victor G. Prieto
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Alexander J. Lazar
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| | - Michael T. Tetzlaff
- Department of Pathology and Laboratory Medicine, Section of Dermatopathology; The University of Texas MD Anderson Cancer Center; Houston TX USA
| |
Collapse
|
30
|
Abstract
Retinoblastoma is a rare pediatric cancer of the retina. Nearly all retinoblastomas are initiated through the biallelic inactivation of the retinoblastoma tumor susceptibility gene (RB1). Whole-genome sequencing has made it possible to identify secondary genetic lesions following RB1 inactivation. One of the major discoveries from retinoblastoma sequencing studies is that some retinoblastoma tumors have stable genomes. Subsequent epigenetic studies showed that changes in the epigenome contribute to the rapid progression of retinoblastoma following RB1 gene inactivation. In addition, gene amplification and elevated expression of p53 antagonists, MDM2 and MDM4, may also play an important role in retinoblastoma tumorigenesis. The knowledge gained from these recent molecular, cellular, genomic, and epigenomic analyses are now being integrated to identify new therapeutic approaches that can help save lives and vision in children with retinoblastoma, with fewer long-term side effects.
Collapse
Affiliation(s)
- Justina D. McEvoy
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, Tennessee
| | - Michael A. Dyer
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, Tennessee
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee
- Howard Hughes Medical Institute, Chevy Chase, Maryland
| |
Collapse
|
31
|
Guerra-Calderas L, González-Barrios R, Herrera LA, Cantú de León D, Soto-Reyes E. The role of the histone demethylase KDM4A in cancer. Cancer Genet 2014; 208:215-24. [PMID: 25633974 DOI: 10.1016/j.cancergen.2014.11.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 10/20/2014] [Accepted: 11/05/2014] [Indexed: 12/31/2022]
Abstract
Histone posttranslational modifications are important components of epigenetic regulation. One extensively studied modification is the methylation of lysine residues. These modifications were thought to be irreversible. However, several proteins with histone lysine demethylase functions have been discovered and characterized. Among these proteins, KDM4A is the first histone lysine demethylase shown to demethylate trimethylated residues. This enzyme plays an important role in gene expression, cellular differentiation, and animal development. Recently, it has also been shown to be involved in cancer. In this review, we focus on describing the structure, mechanisms, and function of KDM4A. We primarily discuss the role of KDM4A in cancer development and the importance of KDM4A as a potential therapeutic target.
Collapse
Affiliation(s)
- Lissania Guerra-Calderas
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Rodrigo González-Barrios
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Luis A Herrera
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - David Cantú de León
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Ernesto Soto-Reyes
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.
| |
Collapse
|
32
|
Witkiewicz AK, Cox D, Knudsen ES. CDK4/6 inhibition provides a potent adjunct to Her2-targeted therapies in preclinical breast cancer models. Genes Cancer 2014; 5:261-72. [PMID: 25221644 PMCID: PMC4162138 DOI: 10.18632/genesandcancer.24] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 08/06/2014] [Indexed: 01/27/2023] Open
Abstract
In spite of the efficacy of Her2-targeted therapies, recurrence and progression remain a challenge for treatment of Her2 positive breast cancer. CDK4/6 controls pathway downstream of Her2, Inhibition of these kinases could represent an important therapeutic approach to augment the effectiveness of standard therapies. In models of acquired resistance to Her2-targeted therapies, Cyclin D1 was inappropriately activated and CDK4/6 inhibition was effective at blocking proliferation by targeting this common pathway associated with resistance. These data were recapitulated in Her2 positive xenografts. Furthermore, in a series of 35 primary breast tumor explants, treatment with PD-0332991 resulted in a greater than 4-fold suppression of the Ki67. The effects of CDK4/6 inhibition were dependent on an intact RB-pathway, and consonantly, loss of RB and high-levels of p16 were associated with resistance to CDK4/6 inhibition. Combination studies illustrated that CDK4/6 inhibition is cooperative with multiple Her2-targeted agents and provides a complementary mechanism of action to T-DM1 to efficiently suppresses the proliferation of residual Her2-positive tumor cell populations that survive T-DM1. Together, these data indicate CDK4/6 is a viable therapeutic target that functions downstream of Her2, and tissue based markers are available to direct rational utilization of CDK4/6 inhibitors in combination with Her2-targeted agents.
Collapse
Affiliation(s)
- Agnieszka K Witkiewicz
- Department of Pathology, Simmons Cancer Center, Dalls, TX ; Department of Pathology, UT Southwestern, Dallas, TX
| | - Derek Cox
- Department of Pathology, Simmons Cancer Center, Dalls, TX
| | - Erik S Knudsen
- Department of Pathology, Simmons Cancer Center, Dalls, TX ; Department of Pathology, UT Southwestern, Dallas, TX
| |
Collapse
|
33
|
Wei D, Goldfarb D, Song S, Cannon C, Yan F, Sakellariou-Thompson D, Emanuele M, Major MB, Weissman BE, Kuwahara Y. SNF5/INI1 deficiency redefines chromatin remodeling complex composition during tumor development. Mol Cancer Res 2014; 12:1574-85. [PMID: 25009291 DOI: 10.1158/1541-7786.mcr-14-0005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED Malignant rhabdoid tumors (MRT), a pediatric cancer that most frequently appears in the kidney and brain, generally lack SNF5 (SMARCB1/INI1), a subunit of the SWI/SNF chromatin-remodeling complex. Recent studies have established that multiple SWI/SNF complexes exist due to the presence or absence of different complex members. Therefore, the effect of SNF5 loss upon SWI/SNF complex formation was investigated in human MRT cells. MRT cells and primary human tumors exhibited reduced levels of many complex proteins. Furthermore, reexpression of SNF5 increased SWI/SNF complex protein levels without concomitant increases in mRNA. Proteomic analysis, using mass spectrometry, of MRT cells before and after SNF5 reexpression indicated the recruitment of different components into the complex along with the expulsion of others. IP-Western blotting confirmed these results and demonstrated similar changes in other MRT cell lines. Finally, reduced expression of SNF5 in normal human fibroblasts led to altered levels of these same complex members. These data establish that SNF5 loss during MRT development alters the repertoire of available SWI/SNF complexes, generally disrupting those associated with cellular differentiation. These findings support a model where SNF5 inactivation blocks the conversion of growth-promoting SWI/SNF complexes to differentiation-inducing ones. Therefore, restoration of these complexes in tumors cells provides an attractive approach for the treatment of MRTs. IMPLICATIONS SNF5 loss dramatically alters SWI/SNF complex composition and prevents formation of complexes required for cellular differentiation.
Collapse
Affiliation(s)
- Darmood Wei
- Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina
| | - Dennis Goldfarb
- Department of Computer Science, University of North Carolina at Chapel Hill, North Carolina
| | - Shujie Song
- Oncology Center, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, China. Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | - Courtney Cannon
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina. Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | - Feng Yan
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | | | - Michael Emanuele
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina. Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | - Michael B Major
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina. Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - Bernard E Weissman
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina. Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina.
| | - Yasumichi Kuwahara
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina. Department of Pediatrics, Kyoto Prefectural University of Medicine, Kyoto, Japan.
| |
Collapse
|
34
|
Yaniv M. Chromatin remodeling: from transcription to cancer. Cancer Genet 2014; 207:352-7. [PMID: 24825771 DOI: 10.1016/j.cancergen.2014.03.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 03/13/2014] [Indexed: 12/15/2022]
Abstract
In this short review article, I have tried to trace the path that led my laboratory from the early studies of the structure of papova minichromosomes and transcription control to the investigation of chromatin remodeling complexes of the SWI/SNF family. I discuss briefly the genetic and biochemical studies that lead to the discovery of the SWI/SNF complex in yeast and drosophila and summarize some of the studies on the developmental role of the murine complex. The discovery of the tumor suppressor function of the SNF5/INI1/SMARCB1 gene in humans and the identification of frequent mutations in other subunits of this complex in different human tumors opened a fascinating field of research on this epigenetic regulator. The hope is to better understand tumor development and to develop novel treatments.
Collapse
Affiliation(s)
- Moshe Yaniv
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Paris, France.
| |
Collapse
|
35
|
The chromatin regulator Brg1 suppresses formation of intraductal papillary mucinous neoplasm and pancreatic ductal adenocarcinoma. Nat Cell Biol 2014; 16:255-67. [PMID: 24561622 DOI: 10.1038/ncb2916] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 01/10/2014] [Indexed: 02/06/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDA) develops through distinct precursor lesions, including pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasia (IPMN). However, genetic features resulting in IPMN-associated PDA (IPMN-PDA) versus PanIN-associated PDA (PanIN-PDA) are largely unknown. Here we find that loss of Brg1, a core subunit of SWI/SNF chromatin remodelling complexes, cooperates with oncogenic Kras to form cystic neoplastic lesions that resemble human IPMN and progress to PDA. Although Brg1-null IPMN-PDA develops rapidly, it possesses a distinct transcriptional profile compared with PanIN-PDA driven by mutant Kras and hemizygous p53 deletion. IPMN-PDA also is less lethal, mirroring prognostic trends in PDA patients. In addition, Brg1 deletion inhibits Kras-dependent PanIN development from adult acinar cells, but promotes Kras-driven preneoplastic transformation in adult duct cells. Therefore, this study implicates Brg1 as a determinant of context-dependent Kras-driven pancreatic tumorigenesis and suggests that chromatin remodelling may underlie the development of distinct PDA subsets.
Collapse
|
36
|
Abstract
The CHD4 (chromodomain-helicase-DNA-binding 4) (or Mi-2β) protein is a founding component of the NuRD (nucleosome remodelling and deacetylation) complex. NuRD has long been known to function in transcriptional regulation, and is conserved throughout the animal and plant kingdoms. In recent years, evidence has steadily accumulated indicating that CHD4 can both function outside of the NuRD complex and also play important roles in cellular processes other than transcriptional regulation. A number of loss-of-function studies have identified important roles for CHD4 in the DNA-damage response and in cell cycle progression through S-phase and into G2. Furthermore, as part of NuRD, it participates in regulating acetylation levels of p53, thereby indirectly regulating the G1/S cell cycle checkpoint. Although CHD4 has a somewhat complicated relationship with the cell cycle, recent evidence indicates that CHD4 may exert some tumour-suppressor functions in human carcinogenesis. CHD4 is a defining member of the NuRD complex, but evidence is accumulating that CHD4 also plays important NuRD-independent roles in the DNA-damage response and cell cycle progression, as well as in transcriptional regulation.
Collapse
|
37
|
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: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [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.
Collapse
Affiliation(s)
- Emily C Dykhuizen
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
|
39
|
BRG1 is required for formation of senescence-associated heterochromatin foci induced by oncogenic RAS or BRCA1 loss. Mol Cell Biol 2013; 33:1819-29. [PMID: 23438604 DOI: 10.1128/mcb.01744-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cellular senescence is an important tumor suppression mechanism. We have previously reported that both oncogene-induced dissociation of BRCA1 from chromatin and BRCA1 knockdown itself drive senescence by promoting formation of senescence-associated heterochromatin foci (SAHF). However, the molecular mechanism by which BRCA1 regulates SAHF formation and senescence is unclear. BRG1 is a chromatin-remodeling factor that interacts with BRCA1 and pRB. Here we show that BRG1 is required for SAHF formation and senescence induced by oncogenic RAS or BRCA1 loss. The interaction between BRG1 and BRCA1 is disrupted during senescence. This correlates with an increased level of chromatin-associated BRG1 in senescent cells. BRG1 knockdown suppresses the formation of SAHF and senescence, while it has no effect on BRCA1 chromatin dissociation induced by oncogenic RAS, indicating that BRG1 functions downstream of BRCA1 chromatin dissociation. Furthermore, BRG1 knockdown inhibits SAHF formation and senescence induced by BRCA1 knockdown. Conversely, BRG1 overexpression drives SAHF formation and senescence in a DNA damage-independent manner. This effect depends upon BRG1's chromatin-remodeling activity as well as the interaction between BRG1 and pRB. Indeed, the interaction between BRG1 and pRB is enhanced during senescence. Chromatin immunoprecipitation analysis revealed that BRG1's association with the human CDKN2A and CDKN1A gene promoters was enhanced during senescence induced by oncogenic RAS or BRCA1 knockdown. Consistently, knockdown of pRB, p21(CIP1), and p16(INK4a), but not p53, suppressed SAHF formation induced by BRG1. Together, these studies reveal the molecular underpinning by which BRG1 acts downstream of BRCA1 to promote SAHF formation and senescence.
Collapse
|
40
|
Imbalzano KM, Cohet N, Wu Q, Underwood JM, Imbalzano AN, Nickerson JA. Nuclear shape changes are induced by knockdown of the SWI/SNF ATPase BRG1 and are independent of cytoskeletal connections. PLoS One 2013; 8:e55628. [PMID: 23405182 PMCID: PMC3566038 DOI: 10.1371/journal.pone.0055628] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 01/02/2013] [Indexed: 11/24/2022] Open
Abstract
Changes in nuclear morphology occur during normal development and have been observed during the progression of several diseases. The shape of a nucleus is governed by the balance of forces exerted by nuclear-cytoskeletal contacts and internal forces created by the structure of the chromatin and nuclear envelope. However, factors that regulate the balance of these forces and determine nuclear shape are poorly understood. The SWI/SNF chromatin remodeling enzyme ATPase, BRG1, has been shown to contribute to the regulation of overall cell size and shape. Here we document that immortalized mammary epithelial cells show BRG1-dependent nuclear shape changes. Specifically, knockdown of BRG1 induced grooves in the nuclear periphery that could be documented by cytological and ultrastructural methods. To test the hypothesis that the observed changes in nuclear morphology resulted from altered tension exerted by the cytoskeleton, we disrupted the major cytoskeletal networks and quantified the frequency of BRG1-dependent changes in nuclear morphology. The results demonstrated that disruption of cytoskeletal networks did not change the frequency of BRG1-induced nuclear shape changes. These findings suggest that BRG1 mediates control of nuclear shape by internal nuclear mechanisms that likely control chromatin dynamics.
Collapse
Affiliation(s)
- Karen M Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | | | | | | | | | | |
Collapse
|
41
|
Ondrušová L, Vachtenheim J, Réda J, Žáková P, Benková K. MITF-independent pro-survival role of BRG1-containing SWI/SNF complex in melanoma cells. PLoS One 2013; 8:e54110. [PMID: 23349796 PMCID: PMC3547967 DOI: 10.1371/journal.pone.0054110] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 12/10/2012] [Indexed: 11/20/2022] Open
Abstract
Metastasized malignant melanoma has a poor prognosis because of its intrinsic resistance to chemotherapy and radiotherapy. The central role in the melanoma transcriptional network has the transcription factor MITF (microphthalmia-associated transcription factor). It has been shown recently that the expression of MITF and some of its target genes require the SWI/SNF chromatin remodeling complex. Here we demonstrate that survival of melanoma cells requires functional SWI/SNF complex not only by supporting expression of MITF and its targets and but also by activating expression of prosurvival proteins not directly regulated by MITF. Microarray analysis revealed that besides the MITF-driven genes, expression of proteins like osteopontin, IGF1, TGFß2 and survivin, the factors known to be generally associated with progression of tumors and the antiapoptotic properties, were reduced in acute BRG1-depleted 501mel cells. Western blots and RT-PCR confirmed the microarray findings. These proteins have been verified to be expressed independently of MITF, because MITF depletion did not impair their expression. Because these genes are not regulated by MITF, the data suggests that loss of BRG1-based SWI/SNF complexes negatively affects survival pathways beyond the MITF cascade. Immunohistochemistry showed high expression of both BRM and BRG1 in primary melanomas. Exogenous CDK2, osteopontin, or IGF1 each alone partly relieved the block of proliferation imposed by BRG1 depletion, implicating that more factors, besides the MITF target genes, are involved in melanoma cell survival. Together these results demonstrate an essential role of SWI/SNF for the expression of MITF-dependent and MITF-independent prosurvival factors in melanoma cells and suggest that SWI/SNF may be a potential and effective target in melanoma therapy.
Collapse
Affiliation(s)
- Lubica Ondrušová
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jiri Vachtenheim
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- * E-mail:
| | - Jiri Réda
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Petra Žáková
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Kamila Benková
- Department of Pathology, Hospital Bulovka, Prague, Czech Republic
| |
Collapse
|
42
|
Xu J, Lei S, Liu Y, Gao X, Irwin MG, Xia ZY, Hei Z, Gan X, Wang T, Xia Z. Antioxidant N-acetylcysteine attenuates the reduction of Brg1 protein expression in the myocardium of type 1 diabetic rats. J Diabetes Res 2013; 2013:716219. [PMID: 23853776 PMCID: PMC3703332 DOI: 10.1155/2013/716219] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 06/01/2013] [Indexed: 02/07/2023] Open
Abstract
Brahma-related gene 1 (Brg1) is a key gene in inducing the expression of important endogenous antioxidant enzymes, including heme oxygenase-1 (HO-1) which is central to cardioprotection, while cardiac HO-1 expression is reduced in diabetes. It is unknown whether or not cardiac Brg1 expression is reduced in diabetes. We hypothesize that cardiac Brg1 expression is reduced in diabetes which can be restored by antioxidant treatment with N-acetylcysteine (NAC). Control (C) and streptozotocin-induced diabetic (D) rats were treated with NAC in drinking water or placebo for 4 weeks. Plasma and cardiac free15-F2t-isoprostane in diabetic rats were increased, accompanied with increased plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6), while cardiac Brg1, p-STAT3 and HO-1 protein expression levels were significantly decreased. Left ventricle weight/body weight ratio was higher, while the peak velocities of early (E) and late (A) flow ratio was lower in diabetic than in C rats. NAC normalized tissue and plasma levels of 15-F2t-isoprostane, significantly increased cardiac Brg1, HO-1 and p-STAT3 protein expression levels and reduced TNF-alpha and IL-6, resulting in improved cardiac function. In conclusion, myocardial Brg1 is reduced in diabetes and enhancement of cardiac Brg1 expression may represent a novel mechanism whereby NAC confers cardioprotection.
Collapse
Affiliation(s)
- Jinjin Xu
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
| | - Shaoqing Lei
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
- Department of Anaesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Yanan Liu
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
| | - Xia Gao
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
| | - Michael G. Irwin
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
| | - Zhong-yuan Xia
- Department of Anaesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Ziqing Hei
- Department of Anesthesiology, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Xiaoliang Gan
- Department of Anesthesiology, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Tingting Wang
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
- Department of Anesthesiology and Critical Care, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, China
- *Tingting Wang: and
| | - Zhengyuan Xia
- Department of Anaesthesiology, The University of Hong Kong, HKSAR, Hong Kong
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical College, Zhanjiang 524001, China
- *Zhengyuan Xia:
| |
Collapse
|
43
|
Numata M, Morinaga S, Watanabe T, Tamagawa H, Yamamoto N, Shiozawa M, Nakamura Y, Kameda Y, Okawa S, Rino Y, Akaike M, Masuda M, Miyagi Y. The clinical significance of SWI/SNF complex in pancreatic cancer. Int J Oncol 2012; 42:403-10. [PMID: 23229642 PMCID: PMC3583622 DOI: 10.3892/ijo.2012.1723] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/05/2012] [Indexed: 12/15/2022] Open
Abstract
Chromatin remodeling factors have been the subject of great interest in oncology. However, little is known about their role in pancreatic cancer. The objective of this study was to clarify the clinical significance of the SWItch/sucrose non-fermentable (SWI/SNF) complex in patients with pancreatic cancer. A total of 68 patients with pancreatic cancer who underwent R0, 1 resection were enrolled. Cancer tissues were processed to tissue microarray, then stained immunohistochemically by using antibody of SWI/SNF components; BRM, BRG1, BAF250a, BAF180 and BAF47. The correlation of expression levels and clinicopathological outcomes were analyzed, followed by the multivariate analysis of prognostic factors for overall survival. The expression levels of the SWI/SNF components were categorized as low or high according to the median value of Histoscore. Statistical analysis revealed that BRM expression was related to tumor size, T factor, M factor, lymphatic invasion and stage BRG1 expression to histology and stage BAF180 expression to tumor size and BAF47 expression to lymphatic invasion, respectively. Multivariate Cox proportional hazard analysis showed that high BRM and low BAF180 expression levels were independent predictors of worse survival in patients with pancreatic cancer. High BRM, and low BAF180 were also independent prognostic factors for poor survival in the subgroup with adjuvant gemcitabine. These results suggest that the specific cofactors of SWI/SNF chromatin remodeling complex certainly have roles in pancreatic cancer. High BRM, and low BAF180 are useful biomarkers for poor prognosis in pancreatic cancer.
Collapse
Affiliation(s)
- Masakatsu Numata
- Department of Gastroenterological Surgery, Kanagawa Cancer Center, Asahi-ku, Yokohama, Kanagawa 241-0815, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Euskirchen G, Auerbach RK, Snyder M. SWI/SNF chromatin-remodeling factors: multiscale analyses and diverse functions. J Biol Chem 2012; 287:30897-905. [PMID: 22952240 PMCID: PMC3438922 DOI: 10.1074/jbc.r111.309302] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chromatin-remodeling enzymes play essential roles in many biological processes, including gene expression, DNA replication and repair, and cell division. Although one such complex, SWI/SNF, has been extensively studied, new discoveries are still being made. Here, we review SWI/SNF biochemistry; highlight recent genomic and proteomic advances; and address the role of SWI/SNF in human diseases, including cancer and viral infections. These studies have greatly increased our understanding of complex nuclear processes.
Collapse
Affiliation(s)
- Ghia Euskirchen
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5120, USA
| | | | | |
Collapse
|
45
|
Talluri S, Dick FA. Regulation of transcription and chromatin structure by pRB: here, there and everywhere. Cell Cycle 2012; 11:3189-98. [PMID: 22895179 PMCID: PMC3466518 DOI: 10.4161/cc.21263] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Commitment to divide is one of the most crucial steps in the mammalian cell division cycle. It is critical for tissue and organismal homeostasis, and consequently is highly regulated. The vast majority of cancers evade proliferative control, further emphasizing the importance of the commitment step in cell cycle regulation. The Retinoblastoma (RB) tumor suppressor pathway regulates this decision-making step. Since being the subject of Knudson's 'two hit hypothesis', there has been considerable interest in understanding pRB's role in cancer. It is best known for repressing E2F dependent transcription of cell cycle genes. However, pRB's role in controlling chromatin structure is expanding and bringing it into new regulatory paradigms. In this review we discuss pRB function through protein-protein interactions, at the level of transcriptional regulation of individual promoters and in organizing higher order chromatin domains.
Collapse
Affiliation(s)
- Srikanth Talluri
- London Regional Cancer Program; Western University; London, ON Canada
- Department of Biochemistry; Western University; London, ON Canada
| | - Frederick A. Dick
- London Regional Cancer Program; Western University; London, ON Canada
- Department of Biochemistry; Western University; London, ON Canada
- Children’s Health Research Institute; Western University; London, ON Canada
| |
Collapse
|
46
|
A novel retinoblastoma therapy from genomic and epigenetic analyses. Nature 2012; 481:329-34. [PMID: 22237022 PMCID: PMC3289956 DOI: 10.1038/nature10733] [Citation(s) in RCA: 377] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2011] [Accepted: 11/24/2011] [Indexed: 01/06/2023]
Abstract
Retinoblastoma is an aggressive childhood cancer of the developing retina that is initiated by the biallelic loss of RB1. Tumours progress very quickly following RB1 inactivation but the underlying mechanism is not known. Here we show that the retinoblastoma genome is stable, but that multiple cancer pathways can be epigenetically deregulated. To identify the mutations that cooperate with RB1 loss, we performed whole-genome sequencing of retinoblastomas. The overall mutational rate was very low; RB1 was the only known cancer gene mutated. We then evaluated the role of RB1 in genome stability and considered non-genetic mechanisms of cancer pathway deregulation. For example, the proto-oncogene SYK is upregulated in retinoblastoma and is required for tumour cell survival. Targeting SYK with a small-molecule inhibitor induced retinoblastoma tumour cell death in vitro and in vivo. Thus, retinoblastomas may develop quickly as a result of the epigenetic deregulation of key cancer pathways as a direct or indirect result of RB1 loss.
Collapse
|
47
|
Slee RB, Steiner CM, Herbert BS, Vance GH, Hickey RJ, Schwarz T, Christan S, Radovich M, Schneider BP, Schindelhauer D, Grimes BR. Cancer-associated alteration of pericentromeric heterochromatin may contribute to chromosome instability. Oncogene 2011; 31:3244-53. [PMID: 22081068 DOI: 10.1038/onc.2011.502] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many tumors exhibit elevated chromosome mis-segregation termed chromosome instability (CIN), which is likely to be a potent driver of tumor progression and drug resistance. Causes of CIN are poorly understood but probably include prior genome tetraploidization, centrosome amplification and mitotic checkpoint defects. This study identifies epigenetic alteration of the centromere as a potential contributor to the CIN phenotype. The centromere controls chromosome segregation and consists of higher-order repeat (HOR) alpha-satellite DNA packaged into two chromatin domains: the kinetochore, harboring the centromere-specific H3 variant centromere protein A (CENP-A), and the pericentromeric heterochromatin, considered important for cohesion. Perturbation of centromeric chromatin in model systems causes CIN. As cancer cells exhibit widespread chromatin changes, we hypothesized that pericentromeric chromatin structure could also be affected, contributing to CIN. Cytological and chromatin immunoprecipitation and PCR (ChIP-PCR)-based analyses of HT1080 cancer cells showed that only one of the two HORs on chromosomes 5 and 7 incorporate CENP-A, an organization conserved in all normal and cancer-derived cells examined. Contrastingly, the heterochromatin marker H3K9me3 (trimethylation of H3 lysine 9) mapped to all four HORs and ChIP-PCR showed an altered pattern of H3K9me3 in cancer cell lines and breast tumors, consistent with a reduction on the kinetochore-forming HORs. The JMJD2B demethylase is overexpressed in breast tumors with a CIN phenotype, and overexpression of exogenous JMJD2B in cultured breast epithelial cells caused loss of centromere-associated H3K9me3 and increased CIN. These findings suggest that impaired maintenance of pericentromeric heterochromatin may contribute to CIN in cancer and be a novel therapeutic target.
Collapse
Affiliation(s)
- R B Slee
- Department of Medical and Molecular Genetics, Indiana University School of Medicine (IUSM), Indianapolis, IN 46202, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Liu JX, Zhou P, Hu ZM, Mao GP. Expression of Brg1, VEGF and COX-2 in Peutz-Jeghers syndrome. Shijie Huaren Xiaohua Zazhi 2011; 19:2461-2466. [DOI: 10.11569/wcjd.v19.i23.2461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To detect the expression of brahma-related gene 1 (Brg1), vascular endothelial growth factor (VEGF) and cyclooxygenase 2 (COX-2) proteins in Peutz-Jeghers syndrome (PJS) and to analyze their clinical significance.
METHODS: Immunohistochemistry was used to detect the expression of Brg1, VEGF and COX-2 proteins in 72 PJS samples, 12 normal small intestinal mucosal tissue samples and 30 cancer tissue samples.
RESULTS: The positive rates of Brg1, VEGF and COX-2 expression were significantly higher in PJS than in normal mucosal tissue (54.17% vs 16.67%, 58.33% vs 8.33%, 62.50% vs 25.00%, all P < 0.01) and in cancer tissue than in PJS (76.67% vs 54.17%, 80.00% vs 58.33%, 83.33% vs 62.50% all P < 0.01). In PJS, positive correlations were found between Brg1 and VEGF expression and between Brg1 and COX-2 expression.
CONCLUSION: Brg1, VEGF and COX-2 may play a role in the occurrence of PJS.
Collapse
|
49
|
Pedrosa E, Sandler V, Shah A, Carroll R, Chang C, Rockowitz S, Guo X, Zheng D, Lachman HM. Development of patient-specific neurons in schizophrenia using induced pluripotent stem cells. J Neurogenet 2011; 25:88-103. [PMID: 21797804 DOI: 10.3109/01677063.2011.597908] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Induced pluripotent stem cell (iPSC) technology has the potential to transform regenerative medicine. It also offers a powerful tool for establishing in vitro models of disease, in particular, for neuropsychiatric disorders where live human neurons are essentially impossible to procure. Using iPSCs derived from three schizophrenia (SZ) patients, one of whom has 22q11.2del (velocardiofacial syndrome; VCFS), the authors developed a culture system to study SZ on a molecular and cellular level. SZ iPSCs were differentiated into functional, primarily glutamatergic neurons that were able to fire action potentials after ∼8 weeks in culture. Early differentiating neurons expressed a number of transcription factors/chromatin remodeling proteins and synaptic proteins relevant to SZ pathogenesis, including ZNF804A, RELN, CNTNAP2, CTNNA2, SMARCA2, and NRXN1. Although a small number of lines were developed in this preliminary study, the SZ line containing 22q11.2del showed a significant delay in the reduction of endogenous OCT4 and NANOG expression that normally occurs during differentiation. Constitutive expression of OCT4 has been observed in Dgcr8-deficient mouse embryonic stem cells (mESCs); DGCR8 maps to the 22q11.2-deleted region. These findings demonstrate that the method of inducing neural differentiation employed is useful for disease modeling in SZ and that the transition of iPSCs with 22q11.2 deletions towards a differentiated state may be marked by subtle changes in expression of pluripotency-associated genes.
Collapse
Affiliation(s)
- Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York 10416, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Sims JK, Wade PA. Mi-2/NuRD complex function is required for normal S phase progression and assembly of pericentric heterochromatin. Mol Biol Cell 2011; 22:3094-102. [PMID: 21737684 PMCID: PMC3164457 DOI: 10.1091/mbc.e11-03-0258] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
During chromosome duplication, it is essential to replicate not only the DNA sequence, but also the complex nucleoprotein structures of chromatin. Pericentric heterochromatin is critical for silencing repetitive elements and plays an essential structural role during mitosis. However, relatively little is understood about its assembly and maintenance during replication. The Mi2/NuRD chromatin remodeling complex tightly associates with actively replicating pericentric heterochromatin, suggesting a role in its assembly. Here we demonstrate that depletion of the catalytic ATPase subunit CHD4/Mi-2β in cells with a dampened DNA damage response results in a slow-growth phenotype characterized by delayed progression through S phase. Furthermore, we observe defects in pericentric heterochromatin maintenance and assembly. Our data suggest that chromatin assembly defects are sensed by an ATM-dependent intra-S phase chromatin quality checkpoint, resulting in a temporal block to the transition from early to late S phase. These findings implicate Mi-2β in the maintenance of chromatin structure and proper cell cycle progression.
Collapse
Affiliation(s)
- Jennifer K Sims
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | | |
Collapse
|