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Hashimoto M, Masuda T, Nakano Y, Tobo T, Saito H, Koike K, Takahashi J, Abe T, Ando Y, Ozato Y, Hosoda K, Higuchi S, Hisamatsu Y, Toshima T, Yonemura Y, Hata T, Uemura M, Eguchi H, Doki Y, Mori M, Mimori K. Tumor suppressive role of the epigenetic master regulator BRD3 in colorectal cancer. Cancer Sci 2024; 115:1866-1880. [PMID: 38494600 PMCID: PMC11145117 DOI: 10.1111/cas.16129] [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: 07/26/2023] [Revised: 02/13/2024] [Accepted: 02/16/2024] [Indexed: 03/19/2024] Open
Abstract
Bromodomain and extraterminal domain (BET) family proteins are epigenetic master regulators of gene expression via recognition of acetylated histones and recruitment of transcription factors and co-activators to chromatin. Hence, BET family proteins have emerged as promising therapeutic targets in cancer. In this study, we examined the functional role of bromodomain containing 3 (BRD3), a BET family protein, in colorectal cancer (CRC). In vitro and vivo analyses using BRD3-knockdown or BRD3-overexpressing CRC cells showed that BRD3 suppressed tumor growth and cell cycle G1/S transition and induced p21 expression. Clinical analysis of CRC datasets from our hospital or The Cancer Genome Atlas revealed that BET family genes, including BRD3, were overexpressed in tumor tissues. In immunohistochemical analyses, BRD3 was observed mainly in the nucleus of CRC cells. According to single-cell RNA sequencing in untreated CRC tissues, BRD3 was highly expressed in malignant epithelial cells, and cell cycle checkpoint-related pathways were enriched in the epithelial cells with high BRD3 expression. Spatial transcriptomic and single-cell RNA sequencing analyses of CRC tissues showed that BRD3 expression was positively associated with high p21 expression. Furthermore, overexpression of BRD3 combined with knockdown of, a driver gene in the BRD family, showed strong inhibition of CRC cells in vitro. In conclusion, we demonstrated a novel tumor suppressive role of BRD3 that inhibits tumor growth by cell cycle inhibition in part via induction of p21 expression. BRD3 activation might be a novel therapeutic approach for CRC.
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Affiliation(s)
- Masahiro Hashimoto
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Takaaki Masuda
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Yusuke Nakano
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Taro Tobo
- Department of PathologyKyushu University Beppu HospitalBeppuJapan
| | - Hideyuki Saito
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Kensuke Koike
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | | | - Tadashi Abe
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Yuki Ando
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Yuki Ozato
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Kiyotaka Hosoda
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Satoshi Higuchi
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | | | - Takeo Toshima
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Yusuke Yonemura
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
| | - Tsuyoshi Hata
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Mamoru Uemura
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Hidetoshi Eguchi
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Yuichiro Doki
- Department of Gastroenterological SurgeryOsaka University Graduate School of MedicineSuitaJapan
| | - Masaki Mori
- Tokai University School of MedicineIseharaJapan
| | - Koshi Mimori
- Department of SurgeryKyushu University Beppu HospitalBeppuJapan
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2
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Morino S, Mashima T, Shirai F, Nagayama S, Katayama R, Seimiya H. BET protein-dependent E2F pathway activity confers bell-shaped type resistance to tankyrase inhibitors in APC-mutated colorectal cancer. Cancer Lett 2024; 584:216632. [PMID: 38216082 DOI: 10.1016/j.canlet.2024.216632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/27/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
WNT/β-catenin signaling is aberrantly activated in colorectal cancer (CRC) mainly by loss-of-function mutations in adenomatous polyposis coli (APC) and is involved in tumor progression. Tankyrase inhibitors, which suppress WNT/β-catenin signaling, are currently in pre-clinical and clinical trials. However, the mechanisms of resistance to tankyrase inhibitors remain unclear. In this study, we established tankyrase inhibitor-resistant CRC cells, JC73-RK100, from APC-mutated patient-derived CRC cells. JC73-RK100 cells and several CRC cell lines were sensitive to tankyrase inhibitors at low concentrations but were resistant at high concentrations, showing an intrinsic/acquired bell-shaped dose response. Mechanistically, tankyrase inhibitors at high concentrations promoted BRD3/4-dependent E2F target gene transcription and over-activated cell cycle progression in these cells. BET inhibitors canceled the bell-shaped dose response to tankyrase inhibitors. Combination of tankyrase and BET inhibitors significantly suppressed tumor growth in a mouse xenograft model. These observations suggest that the combination of tankyrase and BET inhibitors may be a useful therapeutic approach to overcome the resistance of a subset of CRCs to tankyrase inhibitors.
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Affiliation(s)
- Shun Morino
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Tetsuo Mashima
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Fumiyuki Shirai
- Drug Discovery Chemistry Platform Unit, RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan
| | - Satoshi Nagayama
- Department of Colorectal Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan; Department of Surgery, Uji-Tokushukai Medical Center, Kyoto, Japan
| | - Ryohei Katayama
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan; Division of Experimental Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Hiroyuki Seimiya
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
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3
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Palumbo GA, Duminuco A. Myelofibrosis: In Search for BETter Targeted Therapies. J Clin Oncol 2023; 41:5044-5048. [PMID: 37751563 DOI: 10.1200/jco.23.00833] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/22/2023] [Accepted: 07/31/2023] [Indexed: 09/28/2023] Open
Affiliation(s)
- Giuseppe A Palumbo
- Department of Scienze Mediche, Chirurgiche e Tecnologie Avanzate "G.F. Ingrassia," University of Catania, Catania, Italy
| | - Andrea Duminuco
- Postgraduate School of Hematology, University of Catania, Catania, Italy
- Department of Haematology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
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Wahi A, Manchanda N, Jain P, Jadhav HR. Targeting the epigenetic reader "BET" as a therapeutic strategy for cancer. Bioorg Chem 2023; 140:106833. [PMID: 37683545 DOI: 10.1016/j.bioorg.2023.106833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/22/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
Bromodomain and extraterminal (BET) proteins have the ability to bind to acetylated lysine residues present in both histones and non-histone proteins. This binding is facilitated by the presence of tandem bromodomains. The regulatory role of BET proteins extends to chromatin dynamics, cellular processes, and disease progression. The BET family comprises of BRD 2, 3, 4 and BRDT. The BET proteins are a class of epigenetic readers that regulate the transcriptional activity of a multitude of genes that are involved in the pathogenesis of cancer. Thus, targeting BET proteins has been identified as a potentially efficacious approach for the treatment of cancer. BET inhibitors (BETis) are known to interfere with the binding of BET proteins to acetylated lysine residues of chromatin, thereby leading to the suppression of transcription of several genes, including oncogenic transcription factors. Here in this review, we focus on role of Bromodomain and extra C-terminal (BET) proteins in cancer progression. Furthermore, numerous small-molecule inhibitors with pan-BET activity have been documented, with certain compounds currently undergoing clinical assessment. However, it is apparent that the clinical effectiveness of the present BET inhibitors is restricted, prompting the exploration of novel technologies to enhance their clinical outcomes and mitigate undesired adverse effects. Thus, strategies like development of selective BET-BD1, & BD2 inhibitors, dual and acting BET are also presented in this review and attempts to cover the chemistry needed for proper establishment of designed molecules into BRD have been made. Moreover, the review attempts to summarize the details of research till date and proposes a space for future development of BET inhibitor with diminished side effects. It can be concluded that discovery of isoform selective BET inhibitors can be a way forward in order to develop BET inhibitors with negligible side effects.
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Affiliation(s)
- Abhishek Wahi
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, Govt. of NCT of Delhi, Delhi, New Delhi 110017, India
| | - Namish Manchanda
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, Govt. of NCT of Delhi, Delhi, New Delhi 110017, India
| | - Priti Jain
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, Govt. of NCT of Delhi, Delhi, New Delhi 110017, India.
| | - Hemant R Jadhav
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani-Pilani Campus, Vidya Vihar Pilani, Rajasthan 333031, India
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Kumar K, Kanojia D, Bentrem DJ, Hwang RF, Butchar JP, Tridandapani S, Munshi HG. Targeting BET Proteins Decreases Hyaluronidase-1 in Pancreatic Cancer. Cells 2023; 12:1490. [PMID: 37296612 PMCID: PMC10253193 DOI: 10.3390/cells12111490] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is characterized by the presence of dense stroma that is enriched in hyaluronan (HA), with increased HA levels associated with more aggressive disease. Increased levels of the HA-degrading enzymes hyaluronidases (HYALs) are also associated with tumor progression. In this study, we evaluate the regulation of HYALs in PDAC. METHODS Using siRNA and small molecule inhibitors, we evaluated the regulation of HYALs using quantitative real-time PCR (qRT-PCR), Western blot analysis, and ELISA. The binding of BRD2 protein on the HYAL1 promoter was evaluated by chromatin immunoprecipitation (ChIP) assay. Proliferation was evaluated by WST-1 assay. Mice with xenograft tumors were treated with BET inhibitors. The expression of HYALs in tumors was analyzed by immunohistochemistry and by qRT-PCR. RESULTS We show that HYAL1, HYAL2, and HYAL3 are expressed in PDAC tumors and in PDAC and pancreatic stellate cell lines. We demonstrate that inhibitors targeting bromodomain and extra-terminal domain (BET) proteins, which are readers of histone acetylation marks, primarily decrease HYAL1 expression. We show that the BET family protein BRD2 regulates HYAL1 expression by binding to its promoter region and that HYAL1 downregulation decreases proliferation and enhances apoptosis of PDAC and stellate cell lines. Notably, BET inhibitors decrease the levels of HYAL1 expression in vivo without affecting the levels of HYAL2 or HYAL3. CONCLUSIONS Our results demonstrate the pro-tumorigenic role of HYAL1 and identify the role of BRD2 in the regulation of HYAL1 in PDAC. Overall, these data enhance our understanding of the role and regulation of HYAL1 and provide the rationale for targeting HYAL1 in PDAC.
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Affiliation(s)
- Krishan Kumar
- Department of Internal Medicine, Division of Hematology, and Arthur G. James Comprehensive Cancer Center, The Ohio State University College of Medicine, Columbus, OH 43210, USA
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Deepak Kanojia
- Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - David J. Bentrem
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
- Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Rosa F. Hwang
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jonathan P. Butchar
- Department of Internal Medicine, Division of Hematology, and Arthur G. James Comprehensive Cancer Center, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Susheela Tridandapani
- Department of Internal Medicine, Division of Hematology, and Arthur G. James Comprehensive Cancer Center, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Hidayatullah G. Munshi
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
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6
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Quintela M, James DW, Pociute A, Powell L, Edwards K, Coombes Z, Garcia J, Garton N, Das N, Lutchman-Singh K, Margarit L, Beynon AL, Rioja I, Prinjha RK, Harker NR, Gonzalez D, Conlan RS, Francis LW. Bromodomain inhibitor i-BET858 triggers a unique transcriptional response coupled to enhanced DNA damage, cell cycle arrest and apoptosis in high-grade ovarian carcinoma cells. Clin Epigenetics 2023; 15:63. [PMID: 37060086 PMCID: PMC10105475 DOI: 10.1186/s13148-023-01477-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 03/29/2023] [Indexed: 04/16/2023] Open
Abstract
BACKGROUND Ovarian cancer has a specific unmet clinical need, with a persistently poor 5-year survival rate observed in women with advanced stage disease warranting continued efforts to develop new treatment options. The amplification of BRD4 in a significant subset of high-grade serous ovarian carcinomas (HGSC) has led to the development of BET inhibitors (BETi) as promising antitumour agents that have subsequently been evaluated in phase I/II clinical trials. Here, we describe the molecular effects and ex vivo preclinical activities of i-BET858, a bivalent pan-BET inhibitor with proven in vivo BRD inhibitory activity. RESULTS i-BET858 demonstrates enhanced cytotoxic activity compared with earlier generation BETis both in cell lines and primary cells derived from clinical samples of HGSC. At molecular level, i-BET858 triggered a bipartite transcriptional response, comprised of a 'core' network of genes commonly associated with BET inhibition in solid tumours, together with a unique i-BET858 gene signature. Mechanistically, i-BET858 elicited enhanced DNA damage, cell cycle arrest and apoptotic cell death compared to its predecessor i-BET151. CONCLUSIONS Overall, our ex vivo and in vitro studies indicate that i-BET858 represents an optimal candidate to pursue further clinical validation for the treatment of HGSC.
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Affiliation(s)
- Marcos Quintela
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - David W James
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Agne Pociute
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Lydia Powell
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Kadie Edwards
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Zoe Coombes
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Jetzabel Garcia
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Neil Garton
- Immunology Research Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, SG1 2NY, UK
| | - Nagindra Das
- Swansea Bay University Health Board, Swansea, SA12 7BR, UK
| | | | - Lavinia Margarit
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
- Cwm Taf Morgannwg University Health Board, Swansea, SA2 8QA, UK
| | | | - Inmaculada Rioja
- Immunology Research Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, SG1 2NY, UK
| | - Rab K Prinjha
- Immunology Research Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, SG1 2NY, UK
| | - Nicola R Harker
- Immunology Research Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, SG1 2NY, UK
| | - Deyarina Gonzalez
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - R Steven Conlan
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Lewis W Francis
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, UK.
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BET inhibitor trotabresib in heavily pretreated patients with solid tumors and diffuse large B-cell lymphomas. Nat Commun 2023; 14:1359. [PMID: 36914652 PMCID: PMC10011554 DOI: 10.1038/s41467-023-36976-1] [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: 01/14/2022] [Accepted: 02/23/2023] [Indexed: 03/16/2023] Open
Abstract
Bromodomain and extraterminal proteins (BET) play key roles in regulation of gene expression, and may play a role in cancer-cell proliferation, survival, and oncogenic progression. CC-90010-ST-001 (NCT03220347) is an open-label phase I study of trotabresib, an oral BET inhibitor, in heavily pretreated patients with advanced solid tumors and relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Primary endpoints were the safety, tolerability, maximum tolerated dose, and RP2D of trotabresib. Secondary endpoints were clinical benefit rate (complete response [CR] + partial response [PR] + stable disease [SD] of ≥4 months' duration), objective response rate (CR + PR), duration of response or SD, progression-free survival, overall survival, and the pharmacokinetics (PK) of trotabresib. In addition, part C assessed the effects of food on the PK of trotabresib as a secondary endpoint. The dose escalation (part A) showed that trotabresib was well tolerated, had single-agent activity, and determined the recommended phase 2 dose (RP2D) and schedule for the expansion study. Here, we report long-term follow-up results from part A (N = 69) and data from patients treated with the RP2D of 45 mg/day 4 days on/24 days off or an alternate RP2D of 30 mg/day 3 days on/11 days off in the dose-expansion cohorts (parts B [N = 25] and C [N = 41]). Treatment-related adverse events (TRAEs) are reported in almost all patients. The most common severe TRAEs are hematological. Toxicities are generally manageable, allowing some patients to remain on treatment for ≥2 years, with two patients receiving ≥3 years of treatment. Trotabresib monotherapy shows antitumor activity, with an ORR of 13.0% (95% CI, 2.8-33.6) in patients with R/R DLBCL (part B) and an ORR of 0.0% (95% CI, 0.0-8.6) and a CBR of 31.7% (95% CI, 18.1-48.1) in patients with advanced solid tumors (part C). These results support further investigation of trotabresib in combination with other anticancer agents.
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8
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Guo J, Zheng Q, Peng Y. BET proteins: Biological functions and therapeutic interventions. Pharmacol Ther 2023; 243:108354. [PMID: 36739915 DOI: 10.1016/j.pharmthera.2023.108354] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Bromodomain and extra-terminal (BET) family member proteins (BRD2, BRD3, BRD4 and BRDT) play a pivotal role in interpreting the epigenetic information of histone Kac modification, thus controlling gene expression, remodeling chromatin structures and avoid replicative stress-induced DNA damages. Abnormal activation of BET proteins is tightly correlated to various human diseases, including cancer. Therefore, BET bromodomain inhibitors (BBIs) were considered as promising therapeutics to treat BET-related diseases, raising >70 clinical trials in the past decades. Despite preliminary effects achieved, drug resistance and adverse events represent two major challenges for current BBIs development. In this review, we will introduce the biological functions of BET proteins in both physiological and pathological conditions; and summarize the progress in current BBI drug development. Moreover, we will also discuss the major challenges in the front of BET inhibitor development and provide rational strategies to overcome these obstacles.
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Affiliation(s)
- Jiawei Guo
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qingquan Zheng
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yong Peng
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; Frontier Medical Center, Tianfu Jincheng Laboratory, Chengdu, 610212, China.
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9
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BET Proteins as Attractive Targets for Cancer Therapeutics. Int J Mol Sci 2021; 22:ijms222011102. [PMID: 34681760 PMCID: PMC8538173 DOI: 10.3390/ijms222011102] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/04/2021] [Accepted: 10/08/2021] [Indexed: 12/15/2022] Open
Abstract
Transcriptional dysregulation is a hallmark of cancer and can be an essential driver of cancer initiation and progression. Loss of transcriptional control can cause cancer cells to become dependent on certain regulators of gene expression. Bromodomain and extraterminal domain (BET) proteins are epigenetic readers that regulate the expression of multiple genes involved in carcinogenesis. BET inhibitors (BETis) disrupt BET protein binding to acetylated lysine residues of chromatin and suppress the transcription of various genes, including oncogenic transcription factors. Phase I and II clinical trials demonstrated BETis’ potential as anticancer drugs against solid tumours and haematological malignancies; however, their clinical success was limited as monotherapies. Emerging treatment-associated toxicities, drug resistance and a lack of predictive biomarkers limited BETis’ clinical progress. The preclinical evaluation demonstrated that BETis synergised with different classes of compounds, including DNA repair inhibitors, thus supporting further clinical development of BETis. The combination of BET and PARP inhibitors triggered synthetic lethality in cells with proficient homologous recombination. Mechanistic studies revealed that BETis targeted multiple essential homologous recombination pathway proteins, including RAD51, BRCA1 and CtIP. The exact mechanism of BETis’ anticancer action remains poorly understood; nevertheless, these agents provide a novel approach to epigenome and transcriptome anticancer therapy.
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10
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Lara-Ureña N, García-Domínguez M. Relevance of BET Family Proteins in SARS-CoV-2 Infection. Biomolecules 2021; 11:1126. [PMID: 34439792 PMCID: PMC8391731 DOI: 10.3390/biom11081126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 12/14/2022] Open
Abstract
The recent pandemic we are experiencing caused by the coronavirus disease 2019 (COVID-19) has put the world's population on the rack, with more than 191 million cases and more than 4.1 million deaths confirmed to date. This disease is caused by a new type of coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A massive proteomic analysis has revealed that one of the structural proteins of the virus, the E protein, interacts with BRD2 and BRD4 proteins of the Bromodomain and Extra Terminal domain (BET) family of proteins. BETs are essential to cell cycle progression, inflammation and immune response and have also been strongly associated with infection by different types of viruses. The fundamental role BET proteins play in transcription makes them appropriate targets for the propagation strategies of some viruses. Recognition of histone acetylation by BET bromodomains is essential for transcription control. The development of drugs mimicking acetyl groups, and thereby able to displace BET proteins from chromatin, has boosted interest on BETs as attractive targets for therapeutic intervention. The success of these drugs against a variety of diseases in cellular and animal models has been recently enlarged with promising results from SARS-CoV-2 infection studies.
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Affiliation(s)
| | - Mario García-Domínguez
- Andalusian Centre for Molecular Biology and Regenerative Medicine (CABIMER), CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, Av. Américo Vespucio 24, 41092 Seville, Spain;
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11
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García-Gutiérrez P, García-Domínguez M. BETting on a Transcriptional Deficit as the Main Cause for Cornelia de Lange Syndrome. Front Mol Biosci 2021; 8:709232. [PMID: 34386522 PMCID: PMC8353280 DOI: 10.3389/fmolb.2021.709232] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/16/2021] [Indexed: 12/12/2022] Open
Abstract
Cornelia de Lange Syndrome (CdLS) is a human developmental syndrome with complex multisystem phenotypic features. It has been traditionally considered a cohesinopathy together with other phenotypically related diseases because of their association with mutations in subunits of the cohesin complex. Despite some overlap, the clinical manifestations of cohesinopathies vary considerably and, although their precise molecular mechanisms are not well defined yet, the potential pathomechanisms underlying these diverse developmental defects have been theoretically linked to alterations of the cohesin complex function. The cohesin complex plays a critical role in sister chromatid cohesion, but this function is not affected in CdLS. In the last decades, a non-cohesion-related function of this complex on transcriptional regulation has been well established and CdLS pathoetiology has been recently associated to gene expression deregulation. Up to 70% of CdLS cases are linked to mutations in the cohesin-loading factor NIPBL, which has been shown to play a prominent function on chromatin architecture and transcriptional regulation. Therefore, it has been suggested that CdLS can be considered a transcriptomopathy. Actually, CdLS-like phenotypes have been associated to mutations in chromatin-associated proteins, as KMT2A, AFF4, EP300, TAF6, SETD5, SMARCB1, MAU2, ZMYND11, MED13L, PHIP, ARID1B, NAA10, BRD4 or ANKRD11, most of which have no known direct association with cohesin. In the case of BRD4, a critical highly investigated transcriptional coregulator, an interaction with NIPBL has been recently revealed, providing evidence on their cooperation in transcriptional regulation of developmentally important genes. This new finding reinforces the notion of an altered gene expression program during development as the major etiological basis for CdLS. In this review, we intend to integrate the recent available evidence on the molecular mechanisms underlying the clinical manifestations of CdLS, highlighting data that favors a transcription-centered framework, which support the idea that CdLS could be conceptualized as a transcriptomopathy.
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Affiliation(s)
- Pablo García-Gutiérrez
- Andalusian Centre for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, Seville, Spain
| | - Mario García-Domínguez
- Andalusian Centre for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, Seville, Spain
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12
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Zhou L, Han YF, Yuan C, Duan ZQ. Screening and bioinformatics analysis of cellular proteins interacting with chicken bromodomain-containing protein 2 in DF-1 cells. Br Poult Sci 2021; 62:810-819. [PMID: 34152239 DOI: 10.1080/00071668.2021.1943311] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
1. Bromodomain-containing protein 2 (BRD2) is an important member of the BET protein family, which can specifically bind histone acetylated lysine to participate in gene transcriptional regulation, chromatin remodelling, cell proliferation and apoptosis. The following investigation of cellular proteins interacting with chBRD2 will be helpful in understanding the new functions of chBRD2 and the mechanism of NDV replication.2. The recombinant eukaryotic expression vector pEGFP-chBRD2 and empty vector pEGFP-C1 were transfected into DF-1 cells to overexpress GFP-chBRD2 and GFP, respectively. GO annotation, KEGG pathway, and protein-protein interaction network were used to analyse the cellular proteins interacting with chBRD2. In addition, one targeted protein was selected to verify its interaction with chBRD2 using fluorescent co-localisation and Co-IP.3. A total of 225 cellular proteins were identified that potentially interact with chBRD2. GO analysis showed that these play key roles in gene transcriptional regulation, cell cycle and development, immunity and viral infection. Further KEGG pathway analysis showed that these proteins were mainly involved in genetic information processing, immune system, cellular processes and translation. In addition, one targeted cellular protein chicken matrin 3 (chMATR3) was also identified as chBRD2 complex using both fluorescence co-localisation and Co-IP analysis.4. This study presents the interactome data of chBRD2 protein in DF-1 cells, which provides new information to understand the functions of chBRD2 and new targets for further investigating the replication and pathogenesis of NDV.
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Affiliation(s)
- L Zhou
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountains Region, Ministry of Education (Guizhou University)/Key Laboratory of Animal Genetics, Breeding and Reproduction in Guizhou Province, Guiyang, China.,College of Animal Sciences, Guizhou University, Guiyang, China
| | - Y F Han
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountains Region, Ministry of Education (Guizhou University)/Key Laboratory of Animal Genetics, Breeding and Reproduction in Guizhou Province, Guiyang, China.,College of Animal Sciences, Guizhou University, Guiyang, China
| | - C Yuan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountains Region, Ministry of Education (Guizhou University)/Key Laboratory of Animal Genetics, Breeding and Reproduction in Guizhou Province, Guiyang, China.,College of Animal Sciences, Guizhou University, Guiyang, China
| | - Z Q Duan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountains Region, Ministry of Education (Guizhou University)/Key Laboratory of Animal Genetics, Breeding and Reproduction in Guizhou Province, Guiyang, China.,College of Animal Sciences, Guizhou University, Guiyang, China
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13
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Chavez DR, Lee PC, Comizzoli P. Oocyte Meiotic Competence in the Domestic Cat Model: Novel Roles for Nuclear Proteins BRD2 and NPM1. Front Cell Dev Biol 2021; 9:670021. [PMID: 34012967 PMCID: PMC8126674 DOI: 10.3389/fcell.2021.670021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/12/2021] [Indexed: 12/03/2022] Open
Abstract
To participate in fertilization and embryo development, oocytes stored within the mammalian female ovary must resume meiosis as they are arrested in meiotic prophase I. This ability to resume meiosis, known as meiotic competence, requires the tight regulation of cellular metabolism and chromatin configuration. Previously, we identified nuclear proteins associated with the transition from the pre-antral to the antral follicular stage, the time at which oocytes gain meiotic competence. In this study, the objective was to specifically investigate three candidate nuclear factors: bromodomain containing protein 2 (BRD2), nucleophosmin 1 (NPM1), and asparaginase-like 1 (ASRGL1). Although these three factors have been implicated with folliculogenesis or reproductive pathologies, their requirement during oocyte maturation is unproven in any system. Experiments were conducted using different stages of oocytes isolated from adult cat ovaries. The presence of candidate factors in developing oocytes was confirmed by immunostaining. While BRD2 and ASRGL1 protein increased between pre-antral and the antral stages, changes in NPM1 protein levels between stages were not observed. Using protein inhibition experiments, we found that most BRD2 or NPM1-inhibited oocytes were incapable of participating in fertilization or embryo development. Further exploration revealed that inhibition of BRD2 and NPM-1 in cumulus-oocyte-complexes prevented oocytes from maturing to the metaphase II stage. Rather, they remained at the germinal vesicle stage or arrested shortly after meiotic resumption. We therefore have identified novel factors playing critical roles in domestic cat oocyte meiotic competence. The identification of these factors will contribute to improvement of domestic cat assisted reproduction and could serve as biomarkers of meiotically competent oocytes in other species.
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Affiliation(s)
- Daniela R Chavez
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States
| | - Pei-Chih Lee
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States
| | - Pierre Comizzoli
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States
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14
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Shorstova T, Foulkes WD, Witcher M. Achieving clinical success with BET inhibitors as anti-cancer agents. Br J Cancer 2021; 124:1478-1490. [PMID: 33723398 PMCID: PMC8076232 DOI: 10.1038/s41416-021-01321-0] [Citation(s) in RCA: 186] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 01/12/2021] [Accepted: 02/11/2021] [Indexed: 12/16/2022] Open
Abstract
The transcriptional upregulation of oncogenes is a driving force behind the progression of many tumours. However, until a decade ago, the concept of 'switching off' these oncogenic pathways represented a formidable challenge. Research has revealed that members of the bromo- and extra-terminal domain (BET) motif family are key activators of oncogenic networks in a spectrum of cancers; their function depends on their recruitment to chromatin through two bromodomains (BD1 and BD2). The advent of potent inhibitors of BET proteins (BETi), which target either one or both bromodomains, represents an important step towards the goal of suppressing oncogenic networks within tumours. Here, we discuss the biology of BET proteins, advances in BETi design and highlight potential biomarkers predicting their activity. We also outline the logic of incorporating BETi into combination therapies to enhance its efficacy. We suggest that understanding mechanisms of activity, defining predictive biomarkers and identifying potent synergies represents a roadmap for clinical success using BETi.
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Affiliation(s)
- Tatiana Shorstova
- grid.414980.00000 0000 9401 2774Departments of Oncology and Experimental Medicine, McGill University, Lady Davis Institute and Segal Cancer Centre, Jewish General Hospital, Montreal, QC Canada
| | - William D. Foulkes
- grid.414980.00000 0000 9401 2774Departments of Oncology and Human Genetics, McGill University, Lady Davis Institute and Segal Cancer Centre, Jewish General Hospital, Montreal, QC Canada
| | - Michael Witcher
- grid.414980.00000 0000 9401 2774Departments of Oncology and Experimental Medicine, McGill University, Lady Davis Institute and Segal Cancer Centre, Jewish General Hospital, Montreal, QC Canada
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15
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Her YR, Wang L, Chepelev I, Manterola M, Berkovits B, Cui K, Zhao K, Wolgemuth DJ. Genome-wide chromatin occupancy of BRDT and gene expression analysis suggest transcriptional partners and specific epigenetic landscapes that regulate gene expression during spermatogenesis. Mol Reprod Dev 2021; 88:141-157. [PMID: 33469999 DOI: 10.1002/mrd.23449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/13/2020] [Accepted: 12/27/2020] [Indexed: 11/09/2022]
Abstract
BRDT, a member of the BET family of double bromodomain-containing proteins, is essential for spermatogenesis in the mouse and has been postulated to be a key regulator of transcription in meiotic and post-meiotic cells. To understand the function of BRDT in these processes, we first characterized the genome-wide distribution of the BRDT binding sites, in particular within gene units, by ChIP-Seq analysis of enriched fractions of pachytene spermatocytes and round spermatids. In both cell types, BRDT binding sites were mainly located in promoters, first exons, and introns of genes. BRDT binding sites in promoters overlapped with several histone modifications and histone variants associated with active transcription, and were enriched for consensus sequences for specific transcription factors, including MYB, RFX, ETS, and ELF1 in pachytene spermatocytes, and JunD, c-Jun, CRE, and RFX in round spermatids. Subsequent integration of the ChIP-seq data with available transcriptome data revealed that stage-specific gene expression programs are associated with BRDT binding to their gene promoters, with most of the BDRT-bound genes being upregulated. Gene Ontology analysis further identified unique sets of genes enriched in diverse biological processes essential for meiosis and spermiogenesis between the two cell types, suggesting distinct developmentally stage-specific functions for BRDT. Taken together, our data suggest that BRDT cooperates with different transcription factors at distinctive chromatin regions within gene units to regulate diverse downstream target genes that function in male meiosis and spermiogenesis.
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Affiliation(s)
- Yoon Ra Her
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, USA
| | - Li Wang
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, USA
| | - Iouri Chepelev
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.,Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Marcia Manterola
- Human Genetics Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Binyamin Berkovits
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, USA
| | - Kairong Cui
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Keji Zhao
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Debra J Wolgemuth
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, USA.,Department Obstetrics & Gynecology, Columbia University Medical Center, New York, New York, USA.,Institute of Human Nutrition, Columbia University Medical Center, New York, New York, USA.,Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York, USA
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16
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Khera N, Ghayor C, Lindholm AK, Pavlova E, Atanassova N, Weber FE. N, N-Dimethylacetamide, an FDA approved excipient, acts post-meiotically to impair spermatogenesis and cause infertility in rats. CHEMOSPHERE 2020; 256:127001. [PMID: 32447106 DOI: 10.1016/j.chemosphere.2020.127001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/05/2020] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
N, N-Dimethylacetamide is an FDA approved solvent widely used in pharmaceutical industry to facilitate the solubility of lipophilic, high molecular weight drugs with poor water solubility. However, the cytotoxic effects of DMA raises the concern about its use in clinical applications. In the present study, we address the effect of DMA on spermatogenesis. Male Sprague Dawley rats were injected intra-peritoneally for 8 weeks, once a week at a dose of 862 mg/kg. Analysis of reproductive parameters revealed that DMA treated animals exhibit spermatid formation defects within the testis describing the characteristics of oligozoospermia. A subsequent decrease in epididymal sperm concentration along with distortion of sperm morphology was observed. The mitochondrial and microtubule organization in the sperm is considerably modified by DMA. This disrupts the sperm kinetics thus decreasing the total and progressive sperm motility. Finally, DMA treatment resulted in loss of fertility. Our results indicate that exposure to DMA has a negative impact on spermatogenesis and leads to infertility in male rats by inhibiting the post meiotic stages of sperm development. Therefore, the use of DMA in humans must be closely monitored.
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Affiliation(s)
- Nupur Khera
- University of Zurich, Center of Dental Medicine, Oral Biotechnology & Bioengineering, Plattenstrasse11, 8032, Zürich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland
| | - Chafik Ghayor
- University of Zurich, Center of Dental Medicine, Oral Biotechnology & Bioengineering, Plattenstrasse11, 8032, Zürich, Switzerland
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Ekaterina Pavlova
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Nina Atanassova
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Franz E Weber
- University of Zurich, Center of Dental Medicine, Oral Biotechnology & Bioengineering, Plattenstrasse11, 8032, Zürich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland; CABMM, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zürich, Switzerland.
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17
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Role of BET Inhibitors in Triple Negative Breast Cancers. Cancers (Basel) 2020; 12:cancers12040784. [PMID: 32218352 PMCID: PMC7226117 DOI: 10.3390/cancers12040784] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 12/20/2022] Open
Abstract
Bromodomain and extraterminal domain (BET) proteins have evolved as key multifunctional super-regulators that control gene expression. These proteins have been shown to upregulate transcriptional machinery leading to over expression of genes involved in cell proliferation and carcinogenesis. Based on favorable preclinical evidence of BET inhibitors in various cancer models; currently, 26 clinical trials are underway in various stages of study on various hematological and solid organ cancers. Unfortunately, preliminary evidence for these clinical studies does not support the application of BET inhibitors as monotherapy in cancer treatment. Furthermore, the combinatorial efficiency of BET inhibitors with other chemo-and immunotherapeutic agents remain elusive. In this review, we will provide a concise summary of the molecular basis and preliminary clinical outcomes of BET inhibitors in cancer therapy, with special focus on triple negative breast cancer.
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18
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Izumikawa K, Ishikawa H, Yoshikawa H, Fujiyama S, Watanabe A, Aburatani H, Tachikawa H, Hayano T, Miura Y, Isobe T, Simpson RJ, Li L, Min J, Takahashi N. LYAR potentiates rRNA synthesis by recruiting BRD2/4 and the MYST-type acetyltransferase KAT7 to rDNA. Nucleic Acids Res 2019; 47:10357-10372. [PMID: 31504794 PMCID: PMC6821171 DOI: 10.1093/nar/gkz747] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 07/22/2019] [Accepted: 08/20/2018] [Indexed: 02/06/2023] Open
Abstract
Activation of ribosomal RNA (rRNA) synthesis is pivotal during cell growth and proliferation, but its aberrant upregulation may promote tumorigenesis. Here, we demonstrate that the candidate oncoprotein, LYAR, enhances ribosomal DNA (rDNA) transcription. Our data reveal that LYAR binds the histone-associated protein BRD2 without involvement of acetyl-lysine-binding bromodomains and recruits BRD2 to the rDNA promoter and transcribed regions via association with upstream binding factor. We show that BRD2 is required for the recruitment of the MYST-type acetyltransferase KAT7 to rDNA loci, resulting in enhanced local acetylation of histone H4. In addition, LYAR binds a complex of BRD4 and KAT7, which is then recruited to rDNA independently of the BRD2-KAT7 complex to accelerate the local acetylation of both H4 and H3. BRD2 also helps recruit BRD4 to rDNA. By contrast, LYAR has no effect on rDNA methylation or the binding of RNA polymerase I subunits to rDNA. These data suggest that LYAR promotes the association of the BRD2-KAT7 and BRD4-KAT7 complexes with transcription-competent rDNA loci but not to transcriptionally silent rDNA loci, thereby increasing rRNA synthesis by altering the local acetylation status of histone H3 and H4.
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Affiliation(s)
- Keiichi Izumikawa
- Department of Applied Life Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Global Innovation Research Organizations, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Hideaki Ishikawa
- Department of Applied Life Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Harunori Yoshikawa
- Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Sally Fujiyama
- Department of Applied Life Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Akira Watanabe
- Department of Life Science Frontiers, Center for iPS Cell Research and Application, Kyoto University 53, Shogoin-kawahara-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan
| | - Hiroyuki Aburatani
- Laboratory for System Biology and Medicine, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroyuki Tachikawa
- Department of Applied Life Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toshiya Hayano
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu 525-8577, Japan
| | - Yutaka Miura
- Department of Applied Life Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Global Innovation Research Organizations, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Toshiaki Isobe
- Department of Chemistry, Graduate School of Sciences and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - Richard J Simpson
- Global Innovation Research Organizations, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.,La Trobe Institute for Molecular Science (LIMS) LIMS Building 1, Room 412 La Trobe University, Bundoora Victoria 3086, Australia
| | - Li Li
- Structural Genomics Consortium, University of Toronto, 101 College St., Toronto, Ontario M5G 1L7, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jinrong Min
- Global Innovation Research Organizations, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.,Structural Genomics Consortium, University of Toronto, 101 College St., Toronto, Ontario M5G 1L7, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Nobuhiro Takahashi
- Department of Applied Life Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Global Innovation Research Organizations, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
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19
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Walsh L, Haley KE, Moran B, Mooney B, Tarrant F, Madden SF, Di Grande A, Fan Y, Das S, Rueda OM, Dowling CM, Varešlija D, Chin SF, Linn S, Young LS, Jirström K, Crown JP, Bernards R, Caldas C, Gallagher WM, O'Connor DP, Ní Chonghaile T. BET Inhibition as a Rational Therapeutic Strategy for Invasive Lobular Breast Cancer. Clin Cancer Res 2019; 25:7139-7150. [PMID: 31409615 DOI: 10.1158/1078-0432.ccr-19-0713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/13/2019] [Accepted: 08/07/2019] [Indexed: 11/16/2022]
Abstract
PURPOSE Invasive lobular carcinoma (ILC) is a subtype of breast cancer accounting for 10% of breast tumors. The majority of patients are treated with endocrine therapy; however, endocrine resistance is common in estrogen receptor-positive breast cancer and new therapeutic strategies are needed. Bromodomain and extraterminal inhibitors (BETi) are effective in diverse types of breast cancer but they have not yet been assessed in ILC. EXPERIMENTAL DESIGN We assessed whether targeting the BET proteins with JQ1 could serve as an effective therapeutic strategy in ILC in both 2D and 3D models. We used dynamic BH3 profiling and RNA-sequencing (RNA-seq) to identify transcriptional reprograming enabling resistance to JQ1-induced apoptosis. As part of the RATHER study, we obtained copy-number alterations and RNA-seq on 61 ILC patient samples. RESULTS Certain ILC cell lines were sensitive to JQ1, while others were intrinsically resistant to JQ1-induced apoptosis. JQ1 treatment led to an enhanced dependence on antiapoptotic proteins and a transcriptional rewiring inducing fibroblast growth factor receptor 1 (FGFR1). This increase in FGFR1 was also evident in invasive ductal carcinoma (IDC) cell lines. The combination of JQ1 and FGFR1 inhibitors was highly effective at inhibiting growth in both 2D and 3D models of ILC and IDC. Interestingly, we found in the RATHER cohort of 61 ILC patients that 20% had FGFR1 amplification and we showed that high BRD3 mRNA expression was associated with poor survival specifically in ILC. CONCLUSIONS We provide evidence that BETi either alone or in combination with FGFR1 inhibitors or BH3 mimetics may be a useful therapeutic strategy for recurrent ILC patients.
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Affiliation(s)
- Louise Walsh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Kathryn E Haley
- Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Bruce Moran
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Brian Mooney
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Finbarr Tarrant
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Stephen F Madden
- Data Science Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Alessandra Di Grande
- Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Yue Fan
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Sudipto Das
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Oscar M Rueda
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK
| | - Catríona M Dowling
- Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Damir Varešlija
- Endocrine Oncology Research Group, Department of Surgery, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Suet-Feung Chin
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK
| | - Sabine Linn
- Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Leonie S Young
- Endocrine Oncology Research Group, Department of Surgery, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Karin Jirström
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | | | - Rene Bernards
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Carlos Caldas
- Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, England
| | - William M Gallagher
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Darran P O'Connor
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland.
| | - Tríona Ní Chonghaile
- Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
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20
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Reyes-Garau D, Ribeiro ML, Roué G. Pharmacological Targeting of BET Bromodomain Proteins in Acute Myeloid Leukemia and Malignant Lymphomas: From Molecular Characterization to Clinical Applications. Cancers (Basel) 2019; 11:cancers11101483. [PMID: 31581671 PMCID: PMC6826405 DOI: 10.3390/cancers11101483] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 12/16/2022] Open
Abstract
Alterations in protein-protein and DNA-protein interactions and abnormal chromatin remodeling are a major cause of uncontrolled gene transcription and constitutive activation of critical signaling pathways in cancer cells. Multiple epigenetic regulators are known to be deregulated in several hematologic neoplasms, by somatic mutation, amplification, or deletion, allowing the identification of specific epigenetic signatures, but at the same time providing new therapeutic opportunities. While these vulnerabilities have been traditionally addressed by hypomethylating agents or histone deacetylase inhibitors, pharmacological targeting of bromodomain-containing proteins has recently emerged as a promising approach in a number of lymphoid and myeloid malignancies. Indeed, preclinical and clinical studies highlight the relevance of targeting the bromodomain and extra-terminal (BET) family as an efficient strategy of target transcription irrespective of the presence of epigenetic mutations. Here we will summarize the main advances achieved in the last decade regarding the preclinical and clinical evaluation of BET bromodomain inhibitors in hematologic cancers, either as monotherapies or in combinations with standard and/or experimental agents. A mention will finally be given to the new concept of the protein degrader, and the perspective it holds for the design of bromodomain-based therapies.
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Affiliation(s)
- Diana Reyes-Garau
- Laboratory of Experimental Hematology, Department of Hematology, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron University Hospital, Autonomous University of Barcelona, 08035 Barcelona, Spain.
| | - Marcelo L Ribeiro
- Laboratory of Experimental Hematology, Department of Hematology, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron University Hospital, Autonomous University of Barcelona, 08035 Barcelona, Spain.
- Laboratory of Immunopharmacology and Molecular Biology, Sao Francisco University Medical School, Braganca Paulista, São Paulo 12916-900, Brazil.
| | - Gaël Roué
- Laboratory of Experimental Hematology, Department of Hematology, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron University Hospital, Autonomous University of Barcelona, 08035 Barcelona, Spain.
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21
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Zong J, Li S, Wang Y, Mo W, Sun R, Yu M. Bromodomain-containing protein 2 promotes lipolysis via ERK/HSL signalling pathway in white adipose tissue of mice. Gen Comp Endocrinol 2019; 281:105-116. [PMID: 31121164 DOI: 10.1016/j.ygcen.2019.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/17/2019] [Accepted: 05/14/2019] [Indexed: 01/10/2023]
Abstract
White adipose tissue (WAT) dysfunction is prevalent among patients with type 2 diabetes mellitus (T2DM). Uncontrolled free fatty acid (FFA) release from WAT stores has detrimental effects on lipid metabolism, leading to insulin resistance. Bromodomain-containing protein 2 (Brd2) has emerged as a central transcriptional regulator of adipocyte differentiation and pancreatic β-cell bioactivity. A recent study shows that Brd2 overexpression leads to insulin resistance in mice. However, the mechanisms underlying these effects have not been fully elucidated. This study provides the first evidence that adenoviral-mediated Brd2 overexpression in the WAT of mice increases lipolysis-related gene expression in addition to significantly reducing WAT size and promoting plasma FFA release. Brd2 overexpression in adipocytes also inhibits fat synthesis-related gene expression, while activating hormone-sensitive lipase (HSL) expression and ERK-dependent perilipin 1 inhibition as well as promoting glycerol release, which are all involved in lipolysis. Collectively, these results indicate that Brd2 triggers insulin resistance via lipolysis-mediated FFA release.
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Affiliation(s)
- Jiuyu Zong
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai 200032, China
| | - Shuting Li
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai 200032, China
| | - Yuxiong Wang
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai 200032, China
| | - Wei Mo
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai 200032, China
| | - Ruixin Sun
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China.
| | - Min Yu
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai 200032, China.
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The Cornelia de Lange Syndrome-associated factor NIPBL interacts with BRD4 ET domain for transcription control of a common set of genes. Cell Death Dis 2019; 10:548. [PMID: 31320616 PMCID: PMC6639259 DOI: 10.1038/s41419-019-1792-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/17/2019] [Accepted: 07/02/2019] [Indexed: 01/19/2023]
Abstract
Mutations in NIPBL are the major cause of Cornelia de Lange Syndrome (CdLS). NIPBL is the cohesin-loading factor and has recently been associated with the BET (bromodomains and extra-terminal (ET) domain) proteins BRD2 and BRD4. Related to this, a CdLS-like phenotype has been described associated to BRD4 mutations. Here, we show direct interaction of NIPBL with different BET members in yeast, and selective interaction with BRD4 in cells, being the ET domain involved in the interaction. To understand the relationship between NIPBL and BET proteins, we have performed RNA-Seq expression analysis following depletion of the different proteins. Results indicate that genes regulated by NIPBL largely overlap with those regulated by BRD4 but not with those regulated by BRD2. ChIP-Seq analysis indicates preferential NIPBL occupancy at promoters, and knockdown experiments show mutual stabilization of NIPBL and BRD4 on co-regulated promoters. Moreover, human fibroblasts from CdLS probands with mutations in NIPBL show reduced BRD4 at co-occupied promoters. Functional analysis in vivo, using mutants of Drosophila melanogaster, confirmed the genetic interaction between Nipped-B and fs(1)h, the orthologs of human NIPBL and BRD4, respectively. Thus, we provide evidence for NIPBL and BRD4 cooperation in transcriptional regulation, which should contribute to explain the recently observed CdLS-like phenotype associated with BRD4 mutations.
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23
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Handoko L, Kaczkowski B, Hon CC, Lizio M, Wakamori M, Matsuda T, Ito T, Jeyamohan P, Sato Y, Sakamoto K, Yokoyama S, Kimura H, Minoda A, Umehara T. JQ1 affects BRD2-dependent and independent transcription regulation without disrupting H4-hyperacetylated chromatin states. Epigenetics 2018; 13:410-431. [PMID: 30080437 PMCID: PMC6140815 DOI: 10.1080/15592294.2018.1469891] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The bromodomain and extra-terminal domain (BET) proteins are promising drug targets for cancer and immune diseases. However, BET inhibition effects have been studied more in the context of bromodomain-containing protein 4 (BRD4) than BRD2, and the BET protein association to histone H4-hyperacetylated chromatin is not understood at the genome-wide level. Here, we report transcription start site (TSS)-resolution integrative analyses of ChIP-seq and transcriptome profiles in human non-small cell lung cancer (NSCLC) cell line H23. We show that di-acetylation at K5 and K8 of histone H4 (H4K5acK8ac) co-localizes with H3K27ac and BRD2 in the majority of active enhancers and promoters, where BRD2 has a stronger association with H4K5acK8ac than H3K27ac. Although BET inhibition by JQ1 led to complete reduction of BRD2 binding to chromatin, only local changes of H4K5acK8ac levels were observed, suggesting that recruitment of BRD2 does not influence global histone H4 hyperacetylation levels. This finding supports a model in which recruitment of BET proteins via histone H4 hyperacetylation is predominant over hyperacetylation of histone H4 by BET protein-associated acetyltransferases. In addition, we found that a remarkable number of BRD2-bound genes, including MYC and its downstream target genes, were transcriptionally upregulated upon JQ1 treatment. Using BRD2-enriched sites and transcriptional activity analysis, we identified candidate transcription factors potentially involved in the JQ1 response in BRD2-dependent and -independent manner.
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Affiliation(s)
- Lusy Handoko
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Bogumil Kaczkowski
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Chung-Chau Hon
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Marina Lizio
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Masatoshi Wakamori
- b Division of Structural and Synthetic Biology , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Takayoshi Matsuda
- b Division of Structural and Synthetic Biology , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Takuhiro Ito
- b Division of Structural and Synthetic Biology , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Prashanti Jeyamohan
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Yuko Sato
- c Cell Biology Center, Institute of Innovative Research , Tokyo Institute of Technology, Yokohama , Kanagawa , Japan
| | - Kensaku Sakamoto
- b Division of Structural and Synthetic Biology , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | | | - Hiroshi Kimura
- c Cell Biology Center, Institute of Innovative Research , Tokyo Institute of Technology, Yokohama , Kanagawa , Japan
| | - Aki Minoda
- a Division of Genomic Technologies , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan
| | - Takashi Umehara
- b Division of Structural and Synthetic Biology , RIKEN Center for Life Science Technologies, Yokohama , Kanagawa , Japan.,e PRESTO , Japan Science and Technology Agency (JST) , Kawaguchi, Saitama , Japan
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24
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Andrieu GP, Shafran JS, Deeney JT, Bharadwaj KR, Rangarajan A, Denis GV. BET proteins in abnormal metabolism, inflammation, and the breast cancer microenvironment. J Leukoc Biol 2018; 104:265-274. [PMID: 29493812 PMCID: PMC6134394 DOI: 10.1002/jlb.5ri0917-380rr] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/10/2018] [Accepted: 02/10/2018] [Indexed: 12/21/2022] Open
Abstract
Obesity and its associated pathology Type 2 diabetes are two chronic metabolic and inflammatory diseases that promote breast cancer progression, metastasis, and poor outcomes. Emerging critical opinion considers unresolved inflammation and abnormal metabolism separately from obesity; settings where they do not co-occur can inform disease mechanism. In breast cancer, the tumor microenvironment is often infiltrated with T effector and T regulatory cells programmed by metabolic signaling. The pathways by which tumor cells evade immune surveillance, immune therapies, and take advantage of antitumor immunity are poorly understood, but likely depend on metabolic inflammation in the microenvironment. Immune functions are abnormal in metabolic disease, and lessons learned from preclinical studies in lean and metabolically normal environments may not translate to patients with obesity and metabolic disease. This problem is made more urgent by the rising incidence of breast cancer among women who are not obese but who have metabolic disease and associated inflammation, a phenotype common in Asia. The somatic BET proteins, comprising BRD2, BRD3, and BRD4, are new critical regulators of metabolism, coactivate transcription of genes that encode proinflammatory cytokines in immune cell subsets infiltrating the microenvironment, and could be important targets in breast cancer immunotherapy. These transcriptional coregulators are well known to regulate tumor cell progression, but only recently identified as critical for metabolism, metastasis, and expression of immune checkpoint molecules. We consider interrelationships among metabolism, inflammation, and breast cancer aggressiveness relevant to the emerging threat of breast cancer among women with metabolic disease, but without obesity.
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Affiliation(s)
| | - Jordan S. Shafran
- Cancer Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jude T. Deeney
- Department of Medicine, Section of Endocrinology, Obesity Research Center, Evans Biomedical Research Center; Boston University School of Medicine, Boston, Massachusetts, USA
| | - Kishan R. Bharadwaj
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Annapoorni Rangarajan
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Gerald V. Denis
- Cancer Center, Boston University School of Medicine, Boston, Massachusetts, USA
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25
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Itoh Y. Chemical Protein Degradation Approach and its Application to Epigenetic Targets. CHEM REC 2018; 18:1681-1700. [PMID: 29893461 DOI: 10.1002/tcr.201800032] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/24/2018] [Indexed: 12/17/2022]
Abstract
In addition to traditional drugs, such as enzyme inhibitors, receptor agonists/antagonists, and protein-protein interaction inhibitors as well as genetic technology, such as RNA interference and the CRISPR/Cas9 system, protein knockdown approaches using proteolysis-targeting chimeras (PROTACs) have attracted much attention. PROTACs, which induce selective degradation of their target protein via the ubiquitin-proteasome system, are useful for the down-regulation of various proteins, including disease-related proteins and epigenetic proteins. Recent reports have shown that chemical protein knockdown is possible not only in cells, but also in vivo and this approach is expected to be used as the therapeutic strategy for several diseases. Thus, this approach may be a significant technique to complement traditional drugs and genetic ablation and will be more widely used for drug discovery and chemical biology studies in the future. In this personal account, a history of chemical protein knockdown is introduced, and its features, recent progress in the epigenetics field, and future outlooks are discussed.
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Affiliation(s)
- Yukihiro Itoh
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan
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26
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Doroshow DB, Eder JP, LoRusso PM. BET inhibitors: a novel epigenetic approach. Ann Oncol 2018; 28:1776-1787. [PMID: 28838216 DOI: 10.1093/annonc/mdx157] [Citation(s) in RCA: 243] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Epigenetics has been defined as 'the structural adaptation of chromosomal regions so as to register, signal or perpetuate altered activity states.' Currently, several classes of anticancer drugs function at the epigenetic level, including inhibitors of DNA methyltransferase, histone deacetylase (HDAC), lysine-specific demethylase 1, zeste homolog 2, and bromodomain and extra-terminal motif (BET) proteins.BET proteins have multiple functions, including the initiation and elongation of transcription and cell cycle regulation. In recent years, inhibitors of BET proteins have been developed as anticancer agents. These inhibitors exhibit selectivity for tumor cells by preferentially binding to superenhancers, noncoding regions of DNA critical for the transcription of genes that determine a cell's identity. Preclinical research on BET inhibitors has identified them as a potential means of targeting MYC.Early clinical trials with BET inhibitors have had mixed results, with few responses in both hematologic and solid tumors that tend to be short-lived. Toxicities have included severe, thrombocytopenia, fatigue, nausea, vomiting, and diarrhea; GI side-effects, fatigue, and low-grade dysgeusia have limited compliance. However, preclinical data suggest that BET inhibitors may have a promising future in combination with other agents. They appear to be able to overcome resistance to targeted agents and have strong synergy with immune checkpoint inhibitors as well as with multiple epigenetic agents, particularly HDAC inhibitors. In many instances, BET and HDAC inhibitors were synergistic at reduced doses, suggesting a potential means of avoiding the overlapping toxicities of the two drug classes.BET inhibitors provide a novel approach to epigenetic anticancer therapy. However, to date they appear to have limited efficacy as single agents. A focus on BET inhibitors in combination with other drugs such as targeted and/or as other epigenetic agents is warranted, due to limited monotherapy activity, including pharmacodynamic correlatives differential activity amongst select drug combinations.
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Affiliation(s)
- D B Doroshow
- Section of Medical Oncology, Department of Medicine, Yale University and Yale Cancer Center, New Haven, USA
| | - J P Eder
- Section of Medical Oncology, Department of Medicine, Yale University and Yale Cancer Center, New Haven, USA
| | - P M LoRusso
- Section of Medical Oncology, Department of Medicine, Yale University and Yale Cancer Center, New Haven, USA
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27
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Luna-Peláez N, García-Domínguez M. Lyar-Mediated Recruitment of Brd2 to the Chromatin Attenuates Nanog Downregulation Following Induction of Differentiation. J Mol Biol 2018; 430:1084-1097. [PMID: 29505757 DOI: 10.1016/j.jmb.2018.02.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/08/2018] [Accepted: 02/26/2018] [Indexed: 01/24/2023]
Abstract
During development, cellular differentiation programs need tight regulation for proper display of the activity of multiple factors in time and space. Chromatin adaptors of the BET family (Brd2, Brd3, Brd4 and Brdt in vertebrates) are transcription co-regulators tightly associated with the progression of the cell cycle. A key question regarding their function is whether they work as part of the general transcription machinery or, on the contrary, they are precisely recruited to the chromatin through specific transcription factors. Here, we report the selective recruitment of Brd2 to the chromatin by the transcription factor Lyar. We show that Lyar downregulation results in Brd2 dissociation from a number of promoters studied. On the contrary, dissociation of BET proteins from the chromatin has no effect on Lyar occupancy. Under differentiation conditions, the absence of Lyar leads to impaired downregulation of the pluripotency gene Nanog, with concomitant reduction in the upregulation of differentiation markers. Interestingly, following the induction of differentiation, Brd2 depletion exhibits the same effects as expressing a truncated Lyar molecule lacking the Brd2 interacting domain. Both approaches result in stronger Nanog repression, indicating that Lyar-mediated recruitment of Brd2 moderates Nanog downregulation when differentiation is triggered. Moreover, expression of truncated Lyar leads to impaired differentiation and increased apoptosis. Thus, Lyar-mediated recruitment of Brd2 would participate in preserving a proper timing for Nanog silencing ensuring the appropriate establishment of the differentiation program.
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Affiliation(s)
- Noelia Luna-Peláez
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, Av. Américo Vespucio 24, 41092 Seville, Spain
| | - Mario García-Domínguez
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, Av. Américo Vespucio 24, 41092 Seville, Spain.
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28
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Hsu SC, Blobel GA. The Role of Bromodomain and Extraterminal Motif (BET) Proteins in Chromatin Structure. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:37-43. [PMID: 29196562 DOI: 10.1101/sqb.2017.82.033829] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bromodomain and extraterminal motif (BET) proteins have been widely investigated for their roles in gene regulation and their potential as therapeutic targets in cancer. Pharmacologic BET inhibitors target the conserved bromodomain-acetyllysine interaction and do not distinguish between BRD2, BRD3, and BRD4. Thus, comparatively little is known regarding the distinct roles played by individual family members, as well as the underlying mechanisms that drive the transcriptional effects of BET inhibitors. Here we review studies regarding the contributions of BET proteins to genome structure and function, including recent work identifying a role for BRD2 as a component of functional and physical chromatin domain boundaries. We also discuss directions of future studies aimed at providing insights into broader architectural functions of BET proteins and their roles in chromatin domain boundary formation.
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Affiliation(s)
- Sarah C Hsu
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Gerd A Blobel
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
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29
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Knockdown of epigenetic transcriptional co-regulator Brd2a disrupts apoptosis and proper formation of hindbrain and midbrain-hindbrain boundary (MHB) region in zebrafish. Mech Dev 2017; 146:10-30. [PMID: 28549975 DOI: 10.1016/j.mod.2017.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 05/17/2017] [Accepted: 05/22/2017] [Indexed: 01/03/2023]
Abstract
Brd2 is a member of the bromodomain-extraterminal domain (BET) family of proteins and functions as an acetyl-histone-directed transcriptional co-regulator and recruitment scaffold in chromatin modification complexes affecting signal-dependent transcription. While Brd2 acts as a protooncogene in mammalian blood, developmental studies link it to regulation of neuronal apoptosis and epilepsy, and complete knockout of the gene is invariably embryonic lethal. In Drosophila, the Brd2 homolog acts as a maternal effect factor necessary for segment formation and identity and proper expression of homeotic loci, including Ultrabithorax and engrailed. To test the various roles attributed to Brd2 in a single developmental system representing a non-mammalian vertebrate, we conducted a phenotypic characterization of Brd2a deficient zebrafish embryos produced by morpholino knockdown and corroborated by Crispr-Cas9 disruption and small molecule inhibitor treatments. brd2aMO morphants exhibit reduced hindbrain with an ill-defined midbrain-hindbrain boundary (MHB) region; irregular notochord, neural tube, and somites; and abnormalities in ventral trunk and ventral nerve cord interneuron positioning. Using whole mount TUNEL and confocal microscopy, we uncover a significant decrease, then a dramatic increase, of p53-independent cell death at the start and end of segmentation, respectively. In contrast, using qualitative and quantitative analyses of BrdU incorporation, phosphohistone H3-tagging, and flow cytometry, we detect little effect of Brd2a knockdown on overall proliferation levels in embryos. RNA in situ hybridization shows reduced or absent expression of homeobox gene eng2a and paired box gene pax2a, in the hindbrain domain of the MHB region, and an overabundance of pax2a-positive kidney progenitors, in knockdowns. Together, these results suggest an evolutionarily conserved role for Brd2 in the proper formation and/or patterning of segmented tissues, including the vertebrate CNS, where it acts as a bi-modal regulator of apoptosis, and is necessary, directly or indirectly, for proper expression of genes that pattern the MHB and/or regulate differentiation in the anterior hindbrain.
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30
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Padmanabhan B, Mathur S, Manjula R, Tripathi S. Bromodomain and extra-terminal (BET) family proteins: New therapeutic targets in major diseases. J Biosci 2017; 41:295-311. [PMID: 27240990 DOI: 10.1007/s12038-016-9600-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The bromodomains and extra-terminal domain (BET) family proteins recognize acetylated chromatin through their bromodomains (BDs) and help in regulating gene expression. BDs are chromatin 'readers': by interacting with acetylated lysines on the histone tails, they recruit chromatin-regulating proteins on the promoter region to regulate gene expression and repression. Extensive efforts have been employed by scientific communities worldwide to identify and develop potential inhibitors of BET family BDs to regulate protein expression by inhibiting acetylated histone (H3/H4) interactions. Several small molecule inhibitors have been reported, which not only have high affinity but also have high specificity to BET BDs. These developments make BET family proteins an important therapeutic targets for major diseases such as cancer, neurological disorders, obesity and inflammation. Here, we review and discuss the structural biology of BET family BDs and their applications in major diseases.
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Affiliation(s)
- Balasundaram Padmanabhan
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India
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31
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Sun R, Wu Y, Hou W, Sun Z, Wang Y, Wei H, Mo W, Yu M. Bromodomain-containing protein 2 induces insulin resistance via the mTOR/Akt signaling pathway and an inflammatory response in adipose tissue. Cell Signal 2016; 30:92-103. [PMID: 27865874 DOI: 10.1016/j.cellsig.2016.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 11/10/2016] [Accepted: 11/15/2016] [Indexed: 01/02/2023]
Abstract
Insulin resistance is a major metabolic abnormality in a large majority of patients with type II diabetes. Bromodomain-containing protein 2 (Brd2), a transcriptional co-activator/co-repressor with switch mating type/sucrose non-fermenting (SWI/SNF)-like functions that regulates chromatin, suppresses adipocyte differentiation and regulates pancreatic β-cell biology. However, the effects of Brd2 on insulin resistance remain unknown. Here, overexpression of Brd2 in white adipose tissue of wild-type (WT) mice led to insulin resistance. Brd2 overexpression induced the expression of nuclear Factor-κΒ (NF-κΒ) target genes, mainly involving proinflammatory and chemotactic factors, in adipocytes. Furthermore, it decreased the expression of DEP domain containing mTOR-interacting protein (Deptor) to enhance mechanistic target of rapamycin (mTOR) signaling, thus blocking insulin signaling. Collectively, these results provided evidence for a novel role of Brd2 in chronic inflammation and insulin resistance, suggesting its potential in improving insulin resistance and treating metabolic disorders.
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Affiliation(s)
- Ruixin Sun
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yi Wu
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Weihua Hou
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zujun Sun
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yuxiong Wang
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Huanhuan Wei
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Wei Mo
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Min Yu
- The Key Laboratory of Metabolism and Molecular Medicine, The Ministry of Education, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Lori L, Pasquo A, Lori C, Petrosino M, Chiaraluce R, Tallant C, Knapp S, Consalvi V. Effect of BET Missense Mutations on Bromodomain Function, Inhibitor Binding and Stability. PLoS One 2016; 11:e0159180. [PMID: 27403962 PMCID: PMC4942050 DOI: 10.1371/journal.pone.0159180] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/28/2016] [Indexed: 02/03/2023] Open
Abstract
Lysine acetylation is an important epigenetic mark regulating gene transcription and chromatin structure. Acetylated lysine residues are specifically recognized by bromodomains, small protein interaction modules that read these modification in a sequence and acetylation dependent way regulating the recruitment of transcriptional regulators and chromatin remodelling enzymes to acetylated sites in chromatin. Recent studies revealed that bromodomains are highly druggable protein interaction domains resulting in the development of a large number of bromodomain inhibitors. BET bromodomain inhibitors received a lot of attention in the oncology field resulting in the rapid translation of early BET bromodomain inhibitors into clinical studies. Here we investigated the effects of mutations present as polymorphism or found in cancer on BET bromodomain function and stability and the influence of these mutants on inhibitor binding. We found that most BET missense mutations localize to peripheral residues in the two terminal helices. Crystal structures showed that the three dimensional structure is not compromised by these mutations but mutations located in close proximity to the acetyl-lysine binding site modulate acetyl-lysine and inhibitor binding. Most mutations affect significantly protein stability and tertiary structure in solution, suggesting new interactions and an alternative network of protein-protein interconnection as a consequence of single amino acid substitution. To our knowledge this is the first report studying the effect of mutations on bromodomain function and inhibitor binding.
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Affiliation(s)
- Laura Lori
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome, Italy
| | | | - Clorinda Lori
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome, Italy
| | - Maria Petrosino
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome, Italy
| | - Roberta Chiaraluce
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome, Italy
- * E-mail:
| | - Cynthia Tallant
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Stefan Knapp
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Valerio Consalvi
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome, Italy
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Tripathi S, Mathur S, Deshmukh P, Manjula R, Padmanabhan B. A Novel Phenanthridionone Based Scaffold As a Potential Inhibitor of the BRD2 Bromodomain: Crystal Structure of the Complex. PLoS One 2016; 11:e0156344. [PMID: 27243809 PMCID: PMC4886958 DOI: 10.1371/journal.pone.0156344] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/12/2016] [Indexed: 11/18/2022] Open
Abstract
Bromodomain containing proteins recognize the level of histone acetylation and regulate epigenetically controlled processes like gene transcription and chromatin modification. The BET (bromodomain and extra-terminal) family proteins, which are transcriptional co-regulators, have been implicated in the pathogenesis of cancer, neurodegenerative disorders, and defects in embryonic stem cell differentiation. Inhibitors selectively targeting the BET bromodomains can pave the path for new drug discovery against several forms of major diseases. By a rational structure-based approach, we have identified a new inhibitor (NSC127133) of the second bromodomain (BD2) of the BET family protein BRD2 using the NCI Diversity Set III library. A high-resolution crystal structure of the BRD2-BD2 in complex with this compound and in apo- form is refined to 0.91 and 0.94 Å, respectively. The compound, which is a phenanthridinone derivative, binds well to the acetyl-lysine binding pocket of BD2 and displays significant hydrophobic and hydrophilic interactions. Moreover, the atomic resolution data obtained in this study allowed us to visualize certain structural features of BD2 which remained unobserved so far. We propose that the discovered compound may be a potential molecule to develop a new library for inhibiting the BRD2-BD2 function.
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Affiliation(s)
- Shailesh Tripathi
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560029, India
| | - Shruti Mathur
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560029, India
| | - Prashant Deshmukh
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560029, India
| | - Ramu Manjula
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560029, India
| | - Balasundaram Padmanabhan
- Department of Biophysics, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560029, India
- * E-mail: ;
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Deeney JT, Belkina AC, Shirihai OS, Corkey BE, Denis GV. BET Bromodomain Proteins Brd2, Brd3 and Brd4 Selectively Regulate Metabolic Pathways in the Pancreatic β-Cell. PLoS One 2016; 11:e0151329. [PMID: 27008626 PMCID: PMC4805167 DOI: 10.1371/journal.pone.0151329] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/26/2016] [Indexed: 11/18/2022] Open
Abstract
Displacement of Bromodomain and Extra-Terminal (BET) proteins from chromatin has promise for cancer and inflammatory disease treatments, but roles of BET proteins in metabolic disease remain unexplored. Small molecule BET inhibitors, such as JQ1, block BET protein binding to acetylated lysines, but lack selectivity within the BET family (Brd2, Brd3, Brd4, Brdt), making it difficult to disentangle contributions of each family member to transcriptional and cellular outcomes. Here, we demonstrate multiple improvements in pancreatic β-cells upon BET inhibition with JQ1 or BET-specific siRNAs. JQ1 (50–400 nM) increases insulin secretion from INS-1 cells in a concentration dependent manner. JQ1 increases insulin content in INS-1 cells, accounting for increased secretion, in both rat and human islets. Higher concentrations of JQ1 decrease intracellular triglyceride stores in INS-1 cells, a result of increased fatty acid oxidation. Specific inhibition of both Brd2 and Brd4 enhances insulin transcription, leading to increased insulin content. Inhibition of Brd2 alone increases fatty acid oxidation. Overlapping yet discrete roles for individual BET proteins in metabolic regulation suggest new isoform-selective BET inhibitors may be useful to treat insulin resistant/diabetic patients. Results imply that cancer and diseases of chronic inflammation or disordered metabolism are related through shared chromatin regulatory mechanisms.
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Affiliation(s)
- Jude T. Deeney
- Department of Medicine, Section of Endocrinology, Obesity Research Center, Evans Biomedical Research Center; Boston University School of Medicine, 650 Albany Street, X804, Boston, Massachusetts 02118, United States of America
| | - Anna C. Belkina
- Flow Cytometry Core Facility, Boston University School of Medicine, 650 Albany Street, X326, Boston, Massachusetts 02118, United States of America
| | - Orian S. Shirihai
- Department of Medicine, Section of Endocrinology, Obesity Research Center, Evans Biomedical Research Center; Boston University School of Medicine, 650 Albany Street, X804, Boston, Massachusetts 02118, United States of America
| | - Barbara E. Corkey
- Department of Medicine, Section of Endocrinology, Obesity Research Center, Evans Biomedical Research Center; Boston University School of Medicine, 650 Albany Street, X804, Boston, Massachusetts 02118, United States of America
| | - Gerald V. Denis
- Department of Pharmacology and Experimental Therapeutics, and Section of Hematology/ Oncology, Cancer Research Center; Boston University School of Medicine, 72 East Concord Street, K520, Boston, Massachusetts 02118, United States of America
- * E-mail:
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Walsh L, Gallagher WM, O’Connor DP, Ní Chonghaile T. Diagnostic and Therapeutic Implications of Histone Epigenetic Modulators in Breast Cancer. Expert Rev Mol Diagn 2016; 16:541-51. [DOI: 10.1586/14737159.2016.1156534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Louise Walsh
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - William M. Gallagher
- Cancer Biology and Therapeutics Laboratory, UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
- OncoMark Limited, NovaUCD, Belfield Innovation Park, Belfield, Dublin 4, Ireland
| | - Darran P. O’Connor
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Tríona Ní Chonghaile
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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Alghamdi S, Khan I, Beeravolu N, McKee C, Thibodeau B, Wilson G, Chaudhry GR. BET protein inhibitor JQ1 inhibits growth and modulates WNT signaling in mesenchymal stem cells. Stem Cell Res Ther 2016; 7:22. [PMID: 26830473 PMCID: PMC4736146 DOI: 10.1186/s13287-016-0278-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/04/2015] [Accepted: 01/11/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Efficacy and safety of anticancer drugs are traditionally studied using cancer cell lines and animal models. The thienodiazepine class of BET inhibitors, such as JQ1, has been extensively studied for the potential treatment of hematological malignancies and several small molecules belonging to this class are currently under clinical investigation. While these compounds are well known to inhibit cancer cell growth and cause apoptosis, their effects on stem cells, particularly mesenchymal stem cells (MSCs), which are important for regeneration of damaged cells and tissues, are unknown. In this study we employed umbilical cord derived MSCs as a model system to evaluate the safety of JQ1. METHODS Cord derived MSCs were treated with various doses of JQ1 and subjected to cell metabolic activity, apoptosis, and cell cycle analyses using MTT assay, Annexin-V/FITC and PI staining, and flow cytometry, respectively. The effect of JQ1 on gene expression was determined using microarray and quantitative real-time reverse transcriptase polymerase chain reaction analysis. Furthermore, protein expression of apoptotic and neuronal markers was carried out using western blot and immunostaining, respectively. RESULTS Our results showed that JQ1 inhibited cell growth and caused cell cycle arrest in G1 phase but did not induce apoptosis or senescence. JQ1 also down-regulated genes involved in self-renewal, cell cycle, DNA replication, and mitosis, which may have negative implications on the regenerative potential of MSCs. In addition, JQ1 interfered with signaling pathways by down regulating the expression of WNT, resulting in limiting the self-renewal. These results suggest that anticancer agents belonging to the thienodiazepine class of BET inhibitors should be carefully evaluated before their use in cancer therapy. CONCLUSIONS This study revealed for the first time that JQ1 adversely affected MSCs, which are important for repair and regeneration. JQ1 specifically modulated signal transduction and inhibited growth as well as self-renewal. These findings suggest that perinatal MSCs could be used to supplement animal models for investigating the safety of anticancer agents and other drugs.
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Affiliation(s)
- Saeed Alghamdi
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA. .,OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA.
| | - Irfan Khan
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA. .,OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA.
| | - Naimisha Beeravolu
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA. .,OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA.
| | - Christina McKee
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA. .,OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA.
| | | | - George Wilson
- OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA. .,Beaumont Health System, Royal Oak, MI, 48073, USA.
| | - G Rasul Chaudhry
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA. .,OU-WB Institute for Stem Cell and Regenerative Medicine, Oakland University, Rochester, MI, 48309, USA.
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Muralidharan SV, Bhadury J, Nilsson LM, Green LC, McLure KG, Nilsson JA. BET bromodomain inhibitors synergize with ATR inhibitors to induce DNA damage, apoptosis, senescence-associated secretory pathway and ER stress in Myc-induced lymphoma cells. Oncogene 2016; 35:4689-97. [PMID: 26804177 DOI: 10.1038/onc.2015.521] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/08/2015] [Accepted: 12/11/2015] [Indexed: 12/31/2022]
Abstract
Inhibiting the bromodomain and extra-terminal (BET) domain family of epigenetic reader proteins has been shown to have potent anti-tumoral activity, which is commonly attributed to suppression of transcription. In this study, we show that two structurally distinct BET inhibitors (BETi) interfere with replication and cell cycle progression of murine Myc-induced lymphoma cells at sub-lethal concentrations when the transcriptome remains largely unaltered. This inhibition of replication coincides with a DNA-damage response and enhanced sensitivity to inhibitors of the upstream replication stress sensor ATR in vitro and in mouse models of B-cell lymphoma. Mechanistically, ATR and BETi combination therapy cause robust transcriptional changes of genes involved in cell death, senescence-associated secretory pathway, NFkB signaling and ER stress. Our data reveal that BETi can potentiate the cell stress and death caused by ATR inhibitors. This suggests that ATRi can be used in combination therapies of lymphomas without the use of genotoxic drugs.
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Affiliation(s)
- S V Muralidharan
- Department of Surgery, Sahlgrenska Cancer Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - J Bhadury
- Department of Surgery, Sahlgrenska Cancer Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - L M Nilsson
- Department of Surgery, Sahlgrenska Cancer Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - L C Green
- Department of Surgery, Sahlgrenska Cancer Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - K G McLure
- Zenith Epigenetics Corp, Calgary, Alberta, Canada
| | - J A Nilsson
- Department of Surgery, Sahlgrenska Cancer Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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The Epigenetic Reader BRD2 as a Specific Modulator of PAI-1 Expression in Lipopolysaccharide-Stimulated Mouse Primary Astrocytes. Neurochem Res 2015; 40:2211-9. [PMID: 26349765 DOI: 10.1007/s11064-015-1710-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 08/13/2015] [Accepted: 08/25/2015] [Indexed: 12/19/2022]
Abstract
The post translational modification of lysine acetylation is a key mechanism that regulates chromatin structure. Epigenetic readers, such as the BET domains, are responsible for reading histone lysine acetylation which is a hallmark of open chromatin structure, further providing a scaffold that can be accessed by RNA polymerases as well as transcription factors. Recently, several reports have assessed and highlighted the roles of epigenetic readers in various cellular contexts. However, little is known about their role in the regulation of inflammatory genes, which is critical in exquisitely tuning inflammatory responses to a variety of immune stimuli. In this study, we investigated the role of epigenetic readers BRD2 and BRD4 in the lipopolysaccharide (LPS)-induced immune responses in mouse primary astrocytes. Inflammatory stimulation by LPS showed that the levels of Brd2 mRNA and protein were increased, while Brd4 mRNA levels did not change. Knocking down of Brd2 mRNA using specific small interfering RNA (siRNA) in cultured mouse primary astrocytes inhibited LPS-induced mRNA expression and secretion of plasminogen activator inhibitor-1 (PAI-1). However, no other pro-inflammatory cytokines, such as Il-6, Il-1β and Tnf-α, were affected. Indeed, treatment with bromodomain-containing protein inhibitor, JQ1, blocked Pai-1 mRNA expression through the inhibition of direct BRD2 protein-binding and active histone modification on Pai-1 promoter. Taken together, our data suggest that BRD2 is involved in the modulation of neuroinflammatory responses through PAI-1 and via the regulation of epigenetic reader BET protein, further providing a potential novel therapeutic strategy in neuroinflammatory diseases.
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Vardabasso C, Gaspar-Maia A, Hasson D, Pünzeler S, Valle-Garcia D, Straub T, Keilhauer EC, Strub T, Dong J, Panda T, Chung CY, Yao JL, Singh R, Segura MF, Fontanals-Cirera B, Verma A, Mann M, Hernando E, Hake SB, Bernstein E. Histone Variant H2A.Z.2 Mediates Proliferation and Drug Sensitivity of Malignant Melanoma. Mol Cell 2015; 59:75-88. [PMID: 26051178 DOI: 10.1016/j.molcel.2015.05.009] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/24/2015] [Accepted: 04/30/2015] [Indexed: 01/19/2023]
Abstract
Histone variants are emerging as key regulatory molecules in cancer. We report a unique role for the H2A.Z isoform H2A.Z.2 as a driver of malignant melanoma. H2A.Z.2 is highly expressed in metastatic melanoma, correlates with decreased patient survival, and is required for cellular proliferation. Our integrated genomic analyses reveal that H2A.Z.2 controls the transcriptional output of E2F target genes in melanoma cells. These genes are highly expressed and display a distinct signature of H2A.Z occupancy. We identify BRD2 as an H2A.Z-interacting protein, levels of which are also elevated in melanoma. We further demonstrate that H2A.Z.2-regulated genes are bound by BRD2 and E2F1 in an H2A.Z.2-dependent manner. Importantly, H2A.Z.2 deficiency sensitizes melanoma cells to chemotherapy and targeted therapies. Collectively, our findings implicate H2A.Z.2 as a mediator of cell proliferation and drug sensitivity in malignant melanoma, holding translational potential for novel therapeutic strategies.
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Affiliation(s)
- Chiara Vardabasso
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alexandre Gaspar-Maia
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dan Hasson
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sebastian Pünzeler
- Center for Integrated Protein Science Munich and Department of Molecular Biology, Adolf-Butenandt Institute, Ludwig-Maximilians University, 80336 Munich, Germany
| | - David Valle-Garcia
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Molecular Genetics Department, Institute for Cellular Physiology, National Autonomous University of Mexico, 04510 Mexico City, Mexico
| | - Tobias Straub
- Center for Integrated Protein Science Munich and Department of Molecular Biology, Adolf-Butenandt Institute, Ludwig-Maximilians University, 80336 Munich, Germany
| | - Eva C Keilhauer
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Thomas Strub
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Joanna Dong
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Taniya Panda
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chi-Yeh Chung
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jonathan L Yao
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rajendra Singh
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Miguel F Segura
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY 10016, USA
| | - Barbara Fontanals-Cirera
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY 10016, USA
| | - Amit Verma
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Eva Hernando
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY 10016, USA
| | - Sandra B Hake
- Center for Integrated Protein Science Munich and Department of Molecular Biology, Adolf-Butenandt Institute, Ludwig-Maximilians University, 80336 Munich, Germany.
| | - Emily Bernstein
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Uppal T, Banerjee S, Sun Z, Verma SC, Robertson ES. KSHV LANA--the master regulator of KSHV latency. Viruses 2014; 6:4961-98. [PMID: 25514370 PMCID: PMC4276939 DOI: 10.3390/v6124961] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 12/16/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV), like other human herpes viruses, establishes a biphasic life cycle referred to as dormant or latent, and productive or lytic phases. The latent phase is characterized by the persistence of viral episomes in a highly ordered chromatin structure and with the expression of a limited number of viral genes. Latency Associated Nuclear Antigen (LANA) is among the most abundantly expressed proteins during latency and is required for various nuclear functions including the recruitment of cellular machineries for viral DNA replication and segregation of the replicated genomes to daughter cells. LANA achieves these functions by recruiting cellular proteins including replication factors, chromatin modifying enzymes and cellular mitotic apparatus assembly. LANA directly binds to the terminal repeat region of the viral genome and associates with nucleosomal proteins to tether to the host chromosome. Binding of LANA to TR recruits the replication machinery, thereby initiating DNA replication within the TR. However, other regions of the viral genome can also initiate replication as determined by Single Molecule Analysis of the Replicated DNA (SMARD) approach. Recent, next generation sequence analysis of the viral transcriptome shows the expression of additional genes during latent phase. Here, we discuss the newly annotated latent genes and the role of major latent proteins in KSHV biology.
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Affiliation(s)
- Timsy Uppal
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Sagarika Banerjee
- Department of Microbiology and the Tumor Virology Program of the Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Zhiguo Sun
- Department of Microbiology and the Tumor Virology Program of the Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Subhash C Verma
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Erle S Robertson
- Department of Microbiology and the Tumor Virology Program of the Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
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Bagley JA, Yan Z, Zhang W, Wildonger J, Jan LY, Jan YN. Double-bromo and extraterminal (BET) domain proteins regulate dendrite morphology and mechanosensory function. Genes Dev 2014; 28:1940-56. [PMID: 25184680 PMCID: PMC4197945 DOI: 10.1101/gad.239962.114] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A complex array of genetic factors regulates neuronal dendrite morphology. Epigenetic regulation of gene expression represents a plausible mechanism to control pathways responsible for specific dendritic arbor shapes. By studying the Drosophila dendritic arborization (da) neurons, we discovered a role of the double-bromodomain and extraterminal (BET) family proteins in regulating dendrite arbor complexity. A loss-of-function mutation in the single Drosophila BET protein encoded by female sterile 1 homeotic [fs(1)h] causes loss of fine, terminal dendritic branches. Moreover, fs(1)h is necessary for the induction of branching caused by a previously identified transcription factor, Cut (Ct), which regulates subtype-specific dendrite morphology. Finally, disrupting fs(1)h function impairs the mechanosensory response of class III da sensory neurons without compromising the expression of the ion channel NompC, which mediates the mechanosensitive response. Thus, our results identify a novel role for BET family proteins in regulating dendrite morphology and a possible separation of developmental pathways specifying neural cell morphology and ion channel expression. Since the BET proteins are known to bind acetylated histone tails, these results also suggest a role of epigenetic histone modifications and the "histone code," in regulating dendrite morphology.
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Affiliation(s)
- Joshua A Bagley
- Neuroscience Graduate Program, University of California at San Francisco, San Francisco, California 94158, USA; Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
| | - Zhiqiang Yan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
| | - Wei Zhang
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
| | - Jill Wildonger
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
| | - Lily Yeh Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco at San Francisco, California 94158, USA
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Škugor A, Krasnov A, Andersen Ø. Genome-wide microarray analysis of Atlantic cod (Gadus morhua) oocyte and embryo. BMC Genomics 2014; 15:594. [PMID: 25023375 PMCID: PMC4124161 DOI: 10.1186/1471-2164-15-594] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 07/09/2014] [Indexed: 01/06/2023] Open
Abstract
Background Regulation of gene expression plays a central role in embryonic development. Early stages are controlled by gametic transcripts, which are subsequently substituted with transcripts from the genome of the zygote. Transcriptomic analyses provide an efficient approach to explore the temporal gene expression profiles in embryos and to search for the developmental regulators. We report a study of early Atlantic cod development that used a genome-wide oligonucleotide microarray to examine the composition and putative roles of polyadenylated transcripts. Results The analyses were carried out in unfertilized oocytes, newly fertilized oocytes and embryos at the stages of mid-blastula transition and segmentation. Numerous genes transcribed in oocytes are involved in multiple aspects of cell maintenance and protection, including metabolism, signal perception and transduction, RNA processing, cell cycle, defense against pathogens and DNA damage. Transcripts found in unfertilized oocytes also encoded a large number of proteins implicated in cell adherence, tight junction and focal adhesion, suggesting high complexity in terms of structure and cellular interactions in embryos prior to midblastula transition (MBT). Prezygotic transcripts included multiple regulators that are most likely involved in developmental processes that take place long after fertilization, such as components of ErbB, hedgehog, notch, retinoid, TGFb, VEGF and Wnt signaling pathways, as well as transcripts involved in the development of nervous system. The major event of MBT was the activation of a large group of histones and other genes that modify chromatin structure preceding massive gene expression changes. A hallmark of events observed during segmentation was the induction of multiple transcription factors, including a large group of homeobox proteins in pace with decay of a large fraction of maternal transcripts. Microarray analyses detected a suite of master developmental regulators that control differentiation and maintenance of diverse cell lineages. Conclusions Transcriptome profiling of the early stages in Atlantic cod revealed the presence of transcripts involved in patterning and development of tissues and organs long before activation of the zygotic genome. The switch from maternal to zygotic developmental programs is associated with large-scale modification of chromosomes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-594) contains supplementary material, which is available to authorized users.
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Garcia-Gutierrez P, Juarez-Vicente F, Wolgemuth DJ, Garcia-Dominguez M. Pleiotrophin antagonizes Brd2 during neuronal differentiation. J Cell Sci 2014; 127:2554-64. [PMID: 24695857 DOI: 10.1242/jcs.147462] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Bromodomain-containing protein 2 (Brd2) is a BET family chromatin adaptor required for expression of cell-cycle-associated genes and therefore involved in cell cycle progression. Brd2 is expressed in proliferating neuronal progenitors, displays cell-cycle-stimulating activity and, when overexpressed, impairs neuronal differentiation. Paradoxically, Brd2 is also detected in differentiating neurons. To shed light on the role of Brd2 in the transition from cell proliferation to differentiation, we had previously looked for proteins that interacted with Brd2 upon induction of neuronal differentiation. Surprisingly, we identified the growth factor pleiotrophin (Ptn). Here, we show that Ptn antagonized the cell-cycle-stimulating activity associated with Brd2, thus enhancing induced neuronal differentiation. Moreover, Ptn knockdown reduced neuronal differentiation. We analyzed Ptn-mediated antagonism of Brd2 in a cell differentiation model and in two embryonic processes associated with the neural tube: spinal cord neurogenesis and neural crest migration. Finally, we investigated the mechanisms of Ptn-mediated antagonism and determined that Ptn destabilizes the association of Brd2 with chromatin. Thus, Ptn-mediated Brd2 antagonism emerges as a modulation system accounting for the balance between cell proliferation and differentiation in the vertebrate nervous system.
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Affiliation(s)
- Pablo Garcia-Gutierrez
- Stem Cells Department, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER) (Consejo Superior de Investigaciones Cientificas (CSIC), Junta de Andalucía, Universidad de Sevilla, Universidad Pablo de Olavide), Seville 41092, Spain
| | - Francisco Juarez-Vicente
- Stem Cells Department, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER) (Consejo Superior de Investigaciones Cientificas (CSIC), Junta de Andalucía, Universidad de Sevilla, Universidad Pablo de Olavide), Seville 41092, Spain
| | - Debra J Wolgemuth
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Mario Garcia-Dominguez
- Stem Cells Department, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER) (Consejo Superior de Investigaciones Cientificas (CSIC), Junta de Andalucía, Universidad de Sevilla, Universidad Pablo de Olavide), Seville 41092, Spain
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Pastori C, Daniel M, Penas C, Volmar CH, Johnstone AL, Brothers SP, Graham RM, Allen B, Sarkaria JN, Komotar RJ, Wahlestedt C, Ayad NG. BET bromodomain proteins are required for glioblastoma cell proliferation. Epigenetics 2014; 9:611-20. [PMID: 24496381 PMCID: PMC4121371 DOI: 10.4161/epi.27906] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epigenetic proteins have recently emerged as novel anticancer targets. Among these, bromodomain and extra terminal domain (BET) proteins recognize lysine-acetylated histones, thereby regulating gene expression. Newly described small molecules that inhibit BET proteins BRD2, BRD3, and BRD4 reduce proliferation of NUT (nuclear protein in testis)-midline carcinoma, multiple myeloma, and leukemia cells in vitro and in vivo. These findings prompted us to determine whether BET proteins may be therapeutic targets in the most common primary adult brain tumor, glioblastoma (GBM). We performed NanoString analysis of GBM tumor samples and controls to identify novel therapeutic targets. Several cell proliferation assays of GBM cell lines and stem cells were used to analyze the efficacy of the drug I-BET151 relative to temozolomide (TMZ) or cell cycle inhibitors. Lastly, we performed xenograft experiments to determine the efficacy of I-BET151 in vivo. We demonstrate that BRD2 and BRD4 RNA are significantly overexpressed in GBM, suggesting that BET protein inhibition may be an effective means of reducing GBM cell proliferation. Disruption of BRD4 expression in glioblastoma cells reduced cell cycle progression. Similarly, treatment with the BET protein inhibitor I-BET151 reduced GBM cell proliferation in vitro and in vivo. I-BET151 treatment enriched cells at the G1/S cell cycle transition. Importantly, I-BET151 is as potent at inhibiting GBM cell proliferation as TMZ, the current chemotherapy treatment administered to GBM patients. Since I-BET151 inhibits GBM cell proliferation by arresting cell cycle progression, we propose that BET protein inhibition may be a viable therapeutic option for GBM patients suffering from TMZ resistant tumors.
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Affiliation(s)
- Chiara Pastori
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Mark Daniel
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Clara Penas
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Claude-Henry Volmar
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Andrea L Johnstone
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Shaun P Brothers
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Regina M Graham
- Department of Neurosurgery; University of Miami Miller School of Medicine; Miami, FL USA
| | - Bryce Allen
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Jann N Sarkaria
- Department of Radiation Oncology; Mayo Clinic; Rochester, MN USA
| | - Ricardo J Komotar
- Department of Neurosurgery; University of Miami Miller School of Medicine; Miami, FL USA
| | - Claes Wahlestedt
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
| | - Nagi G Ayad
- Center For Therapeutic Innovation; Department of Psychiatry and Behavioral Sciences; University of Miami Miller School of Medicine; Miami, FL USA
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Gallenkamp D, Gelato KA, Haendler B, Weinmann H. Bromodomains and their pharmacological inhibitors. ChemMedChem 2014; 9:438-64. [PMID: 24497428 DOI: 10.1002/cmdc.201300434] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/23/2013] [Indexed: 12/15/2022]
Abstract
Over 60 bromodomains belonging to proteins with very different functions have been identified in humans. Several of them interact with acetylated lysine residues, leading to the recruitment and stabilization of protein complexes. The bromodomain and extra-terminal domain (BET) proteins contain tandem bromodomains which bind to acetylated histones and are thereby implicated in a number of DNA-centered processes, including the regulation of gene expression. The recent identification of inhibitors of BET and non-BET bromodomains is one of the few examples in which effective blockade of a protein-protein interaction can be achieved with a small molecule. This has led to major strides in the understanding of the function of bromodomain-containing proteins and their involvement in diseases such as cancer and inflammation. Indeed, BET bromodomain inhibitors are now being clinically evaluated for the treatment of hematological tumors and have also been tested in clinical trials for the relatively rare BRD-NUT midline carcinoma. This review gives an overview of the newest developments in the field, with a focus on the biology of selected bromodomain proteins on the one hand, and on reported pharmacological inhibitors on the other, including recent examples from the patent literature.
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Kitano Y, Honma T, Hatakeyama Y, Jibu Y, Kawakami Y, Tsuduki T, Nakagawa K, Miyazawa T. Effects of Historical Differences in Components of the Japanese Diet on the Risk of Obesity in Mice. ACTA ACUST UNITED AC 2014. [DOI: 10.4327/jsnfs.67.73] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Chapuy B, McKeown MR, Lin CY, Monti S, Roemer MGM, Qi J, Rahl PB, Sun HH, Yeda KT, Doench JG, Reichert E, Kung AL, Rodig SJ, Young RA, Shipp MA, Bradner JE. Discovery and characterization of super-enhancer-associated dependencies in diffuse large B cell lymphoma. Cancer Cell 2013; 24:777-90. [PMID: 24332044 PMCID: PMC4018722 DOI: 10.1016/j.ccr.2013.11.003] [Citation(s) in RCA: 576] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/17/2013] [Accepted: 11/06/2013] [Indexed: 01/17/2023]
Abstract
Diffuse large B cell lymphoma (DLBCL) is a biologically heterogeneous and clinically aggressive disease. Here, we explore the role of bromodomain and extra-terminal domain (BET) proteins in DLBCL, using integrative chemical genetics and functional epigenomics. We observe highly asymmetric loading of bromodomain 4 (BRD4) at enhancers, with approximately 33% of all BRD4 localizing to enhancers at 1.6% of occupied genes. These super-enhancers prove particularly sensitive to bromodomain inhibition, explaining the selective effect of BET inhibitors on oncogenic and lineage-specific transcriptional circuits. Functional study of genes marked by super-enhancers identifies DLBCLs dependent on OCA-B and suggests a strategy for discovering unrecognized cancer dependencies. Translational studies performed on a comprehensive panel of DLBCLs establish a therapeutic rationale for evaluating BET inhibitors in this disease.
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Affiliation(s)
- Bjoern Chapuy
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Michael R McKeown
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Charles Y Lin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Stefano Monti
- Section of Computational Biomedicine, Boston University School of Medicine, Boston, MA 02118, USA
| | | | - Jun Qi
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Peter B Rahl
- Whitehead Institute of Genome Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Heather H Sun
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Kelly T Yeda
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | | | - Elaine Reichert
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Andrew L Kung
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Scott J Rodig
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Richard A Young
- Whitehead Institute of Genome Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Margaret A Shipp
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
| | - James E Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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Belkina AC, Blanton WP, Nikolajczyk BS, Denis GV. The double bromodomain protein Brd2 promotes B cell expansion and mitogenesis. J Leukoc Biol 2013; 95:451-60. [PMID: 24319289 DOI: 10.1189/jlb.1112588] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bromodomain-containing transcriptional regulators represent new epigenetic targets in different hematologic malignancies. However, bromodomain-mediated mechanisms that couple histone acetylation to transcription in lymphopoiesis and govern mature lymphocyte mitogenesis are poorly understood. Brd2, a transcriptional coregulator that contains dual bromodomains and an extraterminal domain (the BET family), couples chromatin to cell-cycle progression. We reported previously the first functional characterization of a BET protein as an effector of mammalian mitogenic signal transduction: Eμ-Brd2 Tg mice develop "activated B cell" diffuse large B cell lymphoma. No other animal models exist for genetic or lentiviral expression of BET proteins, hampering testing of novel anti-BET anticancer drugs, such as JQ1. We transduced HSCs with Brd2 lentivirus and reconstituted recipient mice to test the hypothesis that Brd2 regulates hematopoiesis in BM and mitogenesis in the periphery. Forced expression of Brd2 provides an expansion advantage to the donor-derived B cell compartment in BM and increases mature B cell mitogenic responsiveness in vitro. Brd2 binds the cyclin A promoter in B cells, shown by ChIP, and increases cyclin A mRNA and protein levels, and S-phase progression in vitro in mitogen-stimulated primary B cells, but not T cells, reinforcing results from Eμ-Brd2 mice. The small molecule BET inhibitor JQ1 reduces B cell mitogenesis, consistent with the interpretation that BET inhibitors are antiproliferative. Brd2-specific knockdown experiments show that Brd2 is also required for hematopoiesis. We conclude that Brd2 plays a critical, independent role in regulation of mitogenic response genes, particularly cyclin A, in B cells.
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Affiliation(s)
- Anna C Belkina
- 1.72 East Concord St., Rm. K520, Boston, MA 02118, USA. ; Twitter: http://www.twitter.com/GdenisBoston
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Hnilicová J, Hozeifi S, Stejskalová E, Dušková E, Poser I, Humpolíčková J, Hof M, Staněk D. The C-terminal domain of Brd2 is important for chromatin interaction and regulation of transcription and alternative splicing. Mol Biol Cell 2013; 24:3557-68. [PMID: 24048450 PMCID: PMC3826993 DOI: 10.1091/mbc.e13-06-0303] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
This study determines genes that are regulated by Brd2 and finds that, in addition to expression control, Brd2 modulates the alternative splicing of several hundred genes. The in vivo interaction of Brd2 with chromatin is analyzed, and the contributions of individual Brd2 domains to the chromatin interaction are determined. Brd2 is a member of the bromodomain extra terminal (BET) protein family, which consists of four chromatin-interacting proteins that regulate gene expression. Each BET protein contains two N-terminal bromodomains, which recognize acetylated histones, and the C-terminal protein–protein interaction domain. Using a genome-wide screen, we identify 1450 genes whose transcription is regulated by Brd2. In addition, almost 290 genes change their alternative splicing pattern upon Brd2 depletion. Brd2 is specifically localized at promoters of target genes, and our data show that Brd2 interaction with chromatin cannot be explained solely by histone acetylation. Using coimmunoprecipitation and live-cell imaging, we show that the C-terminal part is crucial for Brd2 association with chromatin. Live-cell microscopy also allows us to map the average binding time of Brd2 to chromatin and quantify the contributions of individual Brd2 domains to the interaction with chromatin. Finally, we show that bromodomains and the C-terminal domain are equally important for transcription and splicing regulation, which correlates with the role of these domains in Brd2 binding to chromatin.
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Affiliation(s)
- Jarmila Hnilicová
- Department of RNA Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic Max Planck Institute for Molecular Cell Biology and Genetics, Dresden 01307, Germany J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague 182 23, Czech Republic
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50
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Belkina AC, Nikolajczyk BS, Denis GV. BET protein function is required for inflammation: Brd2 genetic disruption and BET inhibitor JQ1 impair mouse macrophage inflammatory responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2013; 190:3670-8. [PMID: 23420887 PMCID: PMC3608815 DOI: 10.4049/jimmunol.1202838] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Histone acetylation regulates activation and repression of multiple inflammatory genes known to play critical roles in chronic inflammatory diseases. However, proteins responsible for translating the histone acetylation code into an orchestrated proinflammatory cytokine response remain poorly characterized. Bromodomain and extraterminal (BET) proteins are "readers" of histone acetylation marks, with demonstrated roles in gene transcription, but the ability of BET proteins to coordinate the response of inflammatory cytokine genes through translation of histone marks is unknown. We hypothesize that members of the BET family of dual bromodomain-containing transcriptional regulators directly control inflammatory genes. We examined the genetic model of brd2 lo mice, a BET protein hypomorph, to show that Brd2 is essential for proinflammatory cytokine production in macrophages. Studies that use small interfering RNA knockdown and a small-molecule inhibitor of BET protein binding, JQ1, independently demonstrate BET proteins are critical for macrophage inflammatory responses. Furthermore, we show that Brd2 and Brd4 physically associate with the promoters of inflammatory cytokine genes in macrophages. This association is absent in the presence of BET inhibition by JQ1. Finally, we demonstrate that JQ1 ablates cytokine production in vitro and blunts the "cytokine storm" in endotoxemic mice by reducing levels of IL-6 and TNF-α while rescuing mice from LPS-induced death. We propose that targeting BET proteins with small-molecule inhibitors will benefit hyperinflammatory conditions associated with high levels of cytokine production.
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Affiliation(s)
- Anna C. Belkina
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Barbara S. Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Gerald V. Denis
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
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