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Latif AL, Newcombe A, Li S, Gilroy K, Robertson NA, Lei X, Stewart HJS, Cole J, Terradas MT, Rishi L, McGarry L, McKeeve C, Reid C, Clark W, Campos J, Kirschner K, Davis A, Lopez J, Sakamaki JI, Morton JP, Ryan KM, Tait SWG, Abraham SA, Holyoake T, Higgins B, Huang X, Blyth K, Copland M, Chevassut TJT, Keeshan K, Adams PD. BRD4-mediated repression of p53 is a target for combination therapy in AML. Nat Commun 2021; 12:241. [PMID: 33431824 PMCID: PMC7801601 DOI: 10.1038/s41467-020-20378-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/25/2020] [Indexed: 12/20/2022] Open
Abstract
Acute myeloid leukemia (AML) is a typically lethal molecularly heterogeneous disease, with few broad-spectrum therapeutic targets. Unusually, most AML retain wild-type TP53, encoding the pro-apoptotic tumor suppressor p53. MDM2 inhibitors (MDM2i), which activate wild-type p53, and BET inhibitors (BETi), targeting the BET-family co-activator BRD4, both show encouraging pre-clinical activity, but limited clinical activity as single agents. Here, we report enhanced toxicity of combined MDM2i and BETi towards AML cell lines, primary human blasts and mouse models, resulting from BETi's ability to evict an unexpected repressive form of BRD4 from p53 target genes, and hence potentiate MDM2i-induced p53 activation. These results indicate that wild-type TP53 and a transcriptional repressor function of BRD4 together represent a potential broad-spectrum synthetic therapeutic vulnerability for AML.
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Affiliation(s)
| | - Ashley Newcombe
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Sha Li
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, USA
| | - Kathryn Gilroy
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Neil A Robertson
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Xue Lei
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, USA
| | - Helen J S Stewart
- Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | - John Cole
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | - Loveena Rishi
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Lynn McGarry
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Claire McKeeve
- West of Scotland Genomics Services (Laboratories), Queen Elizabeth University Hospital, Glasgow, UK
| | - Claire Reid
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | - Joana Campos
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Andrew Davis
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, USA
| | - Jonathan Lopez
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | - Jennifer P Morton
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Stephen W G Tait
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Sheela A Abraham
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Department Of Biomedical And Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Tessa Holyoake
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Brian Higgins
- Pharma Research and Early Development, Roche Innovation Center-New York, New York, USA
| | - Xu Huang
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Karen Blyth
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Mhairi Copland
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Karen Keeshan
- Paul O'Gorman Leukemia Research Centre, Institute of Cancer Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Peter D Adams
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, USA.
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Li S, Latif A, Newcombe A, Gilroy K, Robertson N, Lei X, Finlay D, Stewart H, Barbosa K, Higgins B, Chevassut T, Huang X, Copland M, Keeshan K, Deshpande A, Adams P. Abstract 3426: A synthetic lethality approach to eradicate AML via synergistic activation of pro-apoptotic p53 by MDM2 and BET inhibitors. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-3426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Acute Myeloid Leukemia (AML) is a typically-lethal molecularly heterogeneous disease, with few broad-spectrum therapeutic targets. Unusually, over 90% of AML patients retain wild type TP53, encoding pro-apoptotic tumor suppressor p53. However, wild-type p53 functions are frequently suppressed by MDM2, an E3 ubiquitin ligase that targets p53 for proteasomal degradation. MDM2 inhibitors (MDM2i), which activate wild-type p53, show encouraging pre-clinical activity, but limited clinical activity. In an effort to find targets that synergize with p53 activation and minimize toxicity via MDM2i, we performed a cell-based synthetic lethal drug screen and a CRISPR viability screen. By integrating the results of these two screens, we found inhibition of BRD4 activates p53 and its target genes. BRD4 (Bromodomain-containing protein 4) is a member of the bromodomain and extraterminal (BET) family proteins, which has typically been reported to activate genes, such as c-MYC, BCL2 and CDK4/6. However, we unexpectedly reveal that BRD4 acts as a transcriptional repressor of p53 target genes. Our combined therapy of MDM2i and BETi is synergistically lethal to human AML cell lines harboring wild type p53 in vitro, against two mouse models of AML in vivo, and against several primary human patient blasts in vitro. Synergistic cell killing was associated with synergistic activation of p53 target genes, and cell killing and p53 target gene expression. Taken together, our data show BRD4 represses p53-mediated transcription activation and apoptosis in AML. Therefore, targetable wild-type p53 and a transcriptional repressor function of BRD4 together represent a potential broad-spectrum synthetic therapeutic vulnerability for AML.
Citation Format: Sha Li, Anne Latif, Ashley Newcombe, Kathryn Gilroy, Neil Robertson, Xue Lei, Darren Finlay, Helen Stewart, Karina Barbosa, Brian Higgins, Tim Chevassut, Xu Huang, Mhairi Copland, Karen Keeshan, Ani Deshpande, Peter Adams. A synthetic lethality approach to eradicate AML via synergistic activation of pro-apoptotic p53 by MDM2 and BET inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3426.
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Affiliation(s)
- Sha Li
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Anne Latif
- 2University of Glasgow, Glasgow, United Kingdom
| | | | | | | | - Xue Lei
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Darren Finlay
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | | | - Karina Barbosa
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | | | | | - Xu Huang
- 2University of Glasgow, Glasgow, United Kingdom
| | | | | | - Ani Deshpande
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Peter Adams
- 1Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
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Li S, Latif AL, Newcombe A, Gilrory K, Robertson N, Finlay D, Lei X, Stewart H, Barbosa K, Cole J, Terradas MT, Rishi L, McGarry L, McKeeve C, Reid C, Clark W, Campos J, Kirschner K, Lopez J, Sakamaki JI, Morton J, Ryan K, Tait S, Abraham S, Holyoake T, Higgins B, Huang X, Copland M, Chevassut T, Deshpande A, Keeshan K, Adams P. 3102 – A SYNTHETIC LETHALITY APPROACH TO ERADICATE AML VIA SYNERGISTIC ACTIVATION OF PRO-APOPTOTIC P53 BY MDM2 AND BET INHIBITORS. Exp Hematol 2020. [DOI: 10.1016/j.exphem.2020.09.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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