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Mitra S, Muralidharan SV, Di Marco M, Juvvuna PK, Kosalai ST, Reischl S, Jachimowicz D, Subhash S, Raimondi I, Kurian L, Huarte M, Kogner P, Fischer M, Johnsen JI, Mondal T, Kanduri C. Subcellular Distribution of p53 by the p53-Responsive lncRNA NBAT1 Determines Chemotherapeutic Response in Neuroblastoma. Cancer Res 2021; 81:1457-1471. [PMID: 33372039 DOI: 10.1158/0008-5472.can-19-3499] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/03/2020] [Accepted: 12/16/2020] [Indexed: 11/16/2022]
Abstract
Neuroblastoma has a low mutation rate for the p53 gene. Alternative ways of p53 inactivation have been proposed in neuroblastoma, such as abnormal cytoplasmic accumulation of wild-type p53. However, mechanisms leading to p53 inactivation via cytoplasmic accumulation are not well investigated. Here we show that the neuroblastoma risk-associated locus 6p22.3-derived tumor suppressor NBAT1 is a p53-responsive lncRNA that regulates p53 subcellular levels. Low expression of NBAT1 provided resistance to genotoxic drugs by promoting p53 accumulation in cytoplasm and loss from mitochondrial and nuclear compartments. Depletion of NBAT1 altered CRM1 function and contributed to the loss of p53-dependent nuclear gene expression during genotoxic drug treatment. CRM1 inhibition rescued p53-dependent nuclear functions and sensitized NBAT1-depleted cells to genotoxic drugs. Combined inhibition of CRM1 and MDM2 was even more effective in sensitizing aggressive neuroblastoma cells with p53 cytoplasmic accumulation. Thus, our mechanistic studies uncover an NBAT1-dependent CRM1/MDM2-based potential combination therapy for patients with high-risk neuroblastoma. SIGNIFICANCE: This study shows how a p53-responsive lncRNA mediates chemotherapeutic response by modulating nuclear p53 pathways and identifies a potential treatment strategy for patients with high-risk neuroblastoma.
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Affiliation(s)
- Sanhita Mitra
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | | | - Mirco Di Marco
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Prasanna Kumar Juvvuna
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | | | - Silke Reischl
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Daniel Jachimowicz
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Santhilal Subhash
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Ivan Raimondi
- Cima, University of Navarra, Pio XII, Pamplona, Spain
| | - Leo Kurian
- Center for Molecular Medicine Cologne, Institute for Neurophysiology, The Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany
| | - Maite Huarte
- Cima, University of Navarra, Pio XII, Pamplona, Spain
| | - Per Kogner
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Matthias Fischer
- Department of Experimental Pediatric Oncology, University Children's Hospital of Cologne, Medical Faculty, Cologne, Germany
| | - John Inge Johnsen
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Tanmoy Mondal
- Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
| | - Chandrasekhar Kanduri
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden.
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Muralidharan SV, Einarsdottir BO, Bhadury J, Lindberg MF, Wu J, Campeau E, Bagge RO, Stierner U, Ny L, Nilsson LM, Nilsson JA. BET bromodomain inhibitors synergize with ATR inhibitors in melanoma. Cell Death Dis 2017; 8:e2982. [PMID: 28796244 PMCID: PMC5596569 DOI: 10.1038/cddis.2017.383] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 06/25/2017] [Accepted: 07/02/2017] [Indexed: 01/21/2023]
Abstract
Metastatic malignant melanoma continues to be a challenging disease despite clinical translation of the comprehensive understanding of driver mutations and how melanoma cells evade immune attack. In Myc-driven lymphoma, efficacy of epigenetic inhibitors of the bromodomain and extra-terminal domain (BET) family of bromodomain proteins can be enhanced by combination therapy with inhibitors of the DNA damage response kinase ATR. Whether this combination is active in solid malignancies like melanoma, and how it relates to immune therapy, has not previously investigated. To test efficacy and molecular consequences of combination therapies cultured melanoma cells were used. To assess tumor responses to therapies in vivo we use patient-derived xenografts and B6 mice transplanted with B16F10 melanoma cells. Concomitant inhibition of BET proteins and ATR of cultured melanoma cells resulted in similar effects as recently shown in lymphoma, such as induction of apoptosis and p62, implicated in autophagy, senescence-associated secretory pathway and ER stress. In vivo, apoptosis and suppression of subcutaneous growth of patient-derived melanoma and B16F10 cells were observed. Our data suggest that ATRI/BETI combination therapies are effective in melanoma.
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Affiliation(s)
| | | | - Joydeep Bhadury
- Sahlgrenska Cancer Center, Department of Surgery or University Hospital, Gothenburg, Sweden.,The Institute of Medical Science, Division of Stem Cell Therapy, The University of Tokyo, Tokyo, Japan
| | - Mattias F Lindberg
- Sahlgrenska Cancer Center, Department of Surgery or University Hospital, Gothenburg, Sweden
| | - Jin Wu
- Zenith Epigenetics Ltd, Calgary, Canada
| | | | - Roger Olofsson Bagge
- Sahlgrenska Cancer Center, Department of Surgery or University Hospital, Gothenburg, Sweden
| | - Ulrika Stierner
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg and The Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Lars Ny
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg and The Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Lisa M Nilsson
- Sahlgrenska Cancer Center, Department of Surgery or University Hospital, Gothenburg, Sweden
| | - Jonas A Nilsson
- Sahlgrenska Cancer Center, Department of Surgery or University Hospital, Gothenburg, Sweden
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Lunavat TR, Cheng L, Einarsdottir BO, Olofsson Bagge R, Veppil Muralidharan S, Sharples RA, Lässer C, Gho YS, Hill AF, Nilsson JA, Lötvall J. BRAF V600 inhibition alters the microRNA cargo in the vesicular secretome of malignant melanoma cells. Proc Natl Acad Sci U S A 2017; 114:E5930-E5939. [PMID: 28684402 PMCID: PMC5530690 DOI: 10.1073/pnas.1705206114] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The BRAF inhibitors vemurafenib and dabrafenib can be used to treat patients with metastatic melanomas harboring BRAFV600 mutations. Initial antitumoral responses are often seen, but drug-resistant clones with reactivation of the MEK-ERK pathway soon appear. Recently, the secretome of tumor-derived extracellular vesicles (EVs) has been ascribed important functions in cancers. To elucidate the possible functions of EVs in BRAF-mutant melanoma, we determined the RNA content of the EVs, including apoptotic bodies, microvesicles, and exosomes, released from such cancer cells after vemurafenib treatment. We found that vemurafenib significantly increased the total RNA and protein content of the released EVs and caused significant changes in the RNA profiles. RNA sequencing and quantitative PCR show that cells and EVs from vemurafenib-treated cell cultures and tumor tissues harvested from cell-derived and patient-derived xenografts harbor unique miRNAs, especially increased expression of miR-211-5p. Mechanistically, the expression of miR-211-5p as a result of BRAF inhibition was induced by increased expression of MITF that regulates the TRPM1 gene resulting in activation of the survival pathway. In addition, transfection of miR-211 in melanoma cells reduced the sensitivity to vemurafenib treatment, whereas miR-211-5p inhibition in a vemurafenib resistant cell line affected the proliferation negatively. Taken together, our results show that vemurafenib treatment induces miR-211-5p up-regulation in melanoma cells both in vitro and in vivo, as well as in subsets of EVs, suggesting that EVs may provide a tool to understand malignant melanoma progression.
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Affiliation(s)
- Taral R Lunavat
- Krefting Research Center, Department of Internal Medicine and Clinical Nutrition, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Lesley Cheng
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Berglind O Einarsdottir
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Roger Olofsson Bagge
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Somsundar Veppil Muralidharan
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Robyn A Sharples
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Cecilia Lässer
- Krefting Research Center, Department of Internal Medicine and Clinical Nutrition, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Yong Song Gho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Andrew F Hill
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jonas A Nilsson
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Jan Lötvall
- Krefting Research Center, Department of Internal Medicine and Clinical Nutrition, University of Gothenburg, Gothenburg 405 30, Sweden;
- Codiak BioSciences, Cambridge, MA 02139
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Nilsson LM, Green LC, Muralidharan SV, Demir D, Welin M, Bhadury J, Logan DT, Walse B, Nilsson JA. Cancer Differentiating Agent Hexamethylene Bisacetamide Inhibits BET Bromodomain Proteins. Cancer Res 2016; 76:2376-83. [PMID: 26941288 DOI: 10.1158/0008-5472.can-15-2721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/18/2016] [Indexed: 11/16/2022]
Abstract
Agents that trigger cell differentiation are highly efficacious in treating certain cancers, but such approaches are not generally effective in most malignancies. Compounds such as DMSO and hexamethylene bisacetamide (HMBA) have been used to induce differentiation in experimental systems, but their mechanisms of action and potential range of uses on that basis have not been developed. Here, we show that HMBA, a compound first tested in the oncology clinic over 25 years ago, acts as a selective bromodomain inhibitor. Biochemical and structural studies revealed an affinity of HMBA for the second bromodomain of BET proteins. Accordingly, both HMBA and the prototype BET inhibitor JQ1 induced differentiation of mouse erythroleukemia cells. As expected of a BET inhibitor, HMBA displaced BET proteins from chromatin, caused massive transcriptional changes, and triggered cell-cycle arrest and apoptosis in Myc-induced B-cell lymphoma cells. Furthermore, HMBA exerted anticancer effects in vivo in mouse models of Myc-driven B-cell lymphoma. This study illuminates the function of an early anticancer agent and suggests an intersection with ongoing clinical trials of BET inhibitor, with several implications for predicting patient selection and response rates to this therapy and starting points for generating BD2-selective BET inhibitors. Cancer Res; 76(8); 2376-83. ©2016 AACR.
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Affiliation(s)
- Lisa M Nilsson
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden
| | - Lydia C Green
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden
| | - Somsundar Veppil Muralidharan
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden
| | - Dağsu Demir
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden
| | | | - Joydeep Bhadury
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden
| | | | | | - Jonas A Nilsson
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Cancer Center at University of Gothenburg, Gothenburg, Sweden.
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5
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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Muralidharan SV, Bhadury J, Green L, Nilsson LM, McLure KG, Nilsson JA. Abstract B44: Effects of BET bromodomain inhibitors on replication and cell cycle progression. Mol Cancer Res 2015. [DOI: 10.1158/1557-3125.myc15-b44] [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
Myc family of transcription factors are deregulated in most cancers and their expression projects a poor prognosis. Genetic and pharmacological inhibition of Myc and several Myc targets leads to tumor regression and apoptosis. Recently, inhibitors of BET Bromodomain proteins (BETi) were shown to have anti-tumor properties and this has been attributed to Myc down-regulation. Here we show that two structurally distinct BETi affects replication and cell cycle progression at low concentrations where the transcriptome remains largely unaltered. Thymidine incorporation and flow cytometry analyses demonstrates that S-phase progression is hindered at these concentrations. However, in a cell-free system replication is not impaired suggesting that BETi-mediated block of replication is linked to effects on chromatin. Furthermore, at higher concentration of BETi, S-phase entry of cells is completely abrogated. Ectopic expression of Myc fails to rescue these phenotypes, suggesting a novel function of BET bromodomain proteins in replication and cell cycle regulation. Our pharmacogenetic screen in the presence of sub-lethal doses of BETi has identified several small molecule inhibitors to synergize with BETi to enhance apoptosis of Myc driven tumors.
Citation Format: Somsundar Veppil Muralidharan, Joydeep Bhadury, Lydia Green, Lisa M. Nilsson, Kevin G. McLure, Jonas A. Nilsson. Effects of BET bromodomain inhibitors on replication and cell cycle progression. [abstract]. In: Proceedings of the AACR Special Conference on Myc: From Biology to Therapy; Jan 7-10, 2015; La Jolla, CA. Philadelphia (PA): AACR; Mol Cancer Res 2015;13(10 Suppl):Abstract nr B44.
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Affiliation(s)
| | | | - Lydia Green
- 1University of Gothenburg, Gothenburg, Sweden,
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Sheng M, Hosseinzadeh A, Muralidharan SV, Gaur R, Selstam E, Tuck S. Aberrant fat metabolism in Caenorhabditis elegans mutants with defects in the defecation motor program. PLoS One 2015; 10:e0124515. [PMID: 25849533 PMCID: PMC4388766 DOI: 10.1371/journal.pone.0124515] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 03/16/2015] [Indexed: 01/08/2023] Open
Abstract
The molecular mechanisms by which dietary fatty acids are absorbed by the intestine, and the way in which the process is regulated are poorly understood. In a genetic screen for mutations affecting fat accumulation in the intestine of Caenorhabditis elegans, nematode worms, we have isolated mutations in the aex-5 gene, which encodes a Kex2/subtilisin-family, Ca2+-sensitive proprotein convertase known to be required for maturation of certain neuropeptides, and for a discrete step in an ultradian rhythmic phenomenon called the defecation motor program. We demonstrate that aex-5 mutants have markedly lower steady-state levels of fat in the intestine, and that this defect is associated with a significant reduction in the rate at which labeled fatty acid derivatives are taken up from the intestinal lumen. Other mutations affecting the defecation motor program also affect steady-state levels of triglycerides, suggesting that the program is required per se for the proper accumulation of neutral lipids. Our results suggest that an important function of the defecation motor program in C. elegans is to promote the uptake of an important class of dietary nutrients. They also imply that modulation of the program might be one way in which worms adjust nutrient uptake in response to altered metabolic status.
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Affiliation(s)
- Ming Sheng
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | - Ava Hosseinzadeh
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | | | - Rahul Gaur
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | - Eva Selstam
- Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
| | - Simon Tuck
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
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Muralidharan SV, Bhadury J, Green L, Nilsson LM, Mclure KG, Nilsson JA. Abstract 4565: Bet bromodomain inhibitors affects replication & cell cycle progression. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-4565] [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
Myc family of transcription factors contribute to pathogenesis in most cancers and their expression projects a poor prognosis. Genetic and pharmacological inhibition of Myc and several Myc targets leads to apoptosis and tumor regression. Recently, inhibitors of BET Bromodomain proteins (BETi) were shown to have anti-tumor properties and this has been attributed to Myc down-regulation. In this study, we show that two structurally distinct BETi affects replication and cell cycle progression at low concentrations where the transcriptome remains largely unaltered. At these concentrations, S-phase progression is hindered, as assessed by thymidine incorporation and flow cytometry analyses. However, in a cell-free system replication is not impaired suggesting that BETi-mediated block of replication is linked to effects on chromatin. Furthermore, at higher concentration of BET, S-phase entry of cells is completely abrogated. Ectopic expression of Myc fails to rescue these phenotypes, suggesting a novel function of BET bromodomain proteins in replication and cell cycle regulation.
Citation Format: Somsundar Veppil Muralidharan, Joydeep Bhadury, Lydia Green, Lisa M. Nilsson, Kevin G. Mclure, Jonas A. Nilsson. Bet bromodomain inhibitors affects replication & cell cycle progression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4565. doi:10.1158/1538-7445.AM2014-4565
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Affiliation(s)
| | | | - Lydia Green
- 1University of Gothenburg, Gothenburg, Sweden
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Höglund A, Nilsson LM, Muralidharan SV, Hasvold LA, Merta P, Rudelius M, Nikolova V, Keller U, Nilsson JA. Therapeutic implications for the induced levels of Chk1 in Myc-expressing cancer cells. Clin Cancer Res 2011; 17:7067-79. [PMID: 21933891 DOI: 10.1158/1078-0432.ccr-11-1198] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The transcription factor c-Myc (or "Myc") is a master regulator of pathways driving cell growth and proliferation. MYC is deregulated in many human cancers, making its downstream target genes attractive candidates for drug development. We report the unexpected finding that B-cell lymphomas from mice and patients exhibit a striking correlation between high levels of Myc and checkpoint kinase 1 (Chk1). EXPERIMENTAL DESIGN By in vitro cell biology studies as well as preclinical studies using a genetically engineered mouse model, we evaluated the role of Chk1 in Myc-overexpressing cells. RESULTS We show that Myc indirectly induces Chek1 transcript and protein expression, independently of DNA damage response proteins such as ATM and p53. Importantly, we show that inhibition of Chk1, by either RNA interference or a novel highly selective small molecule inhibitor, results in caspase-dependent apoptosis that affects Myc-overexpressing cells in both in vitro and in vivo mouse models of B-cell lymphoma. CONCLUSION Our data suggest that Chk1 inhibitors should be further evaluated as potential drugs against Myc-driven malignancies such as certain B-cell lymphoma/leukemia, neuroblastoma, and some breast and lung cancers.
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Affiliation(s)
- Andreas Höglund
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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