101
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Yin J, Ni B, Liao WG, Gao YQ. Hypoxia-induced apoptosis of mouse spermatocytes is mediated by HIF-1α through a death receptor pathway and a mitochondrial pathway. J Cell Physiol 2017; 233:1146-1155. [PMID: 28444885 DOI: 10.1002/jcp.25974] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 04/24/2017] [Indexed: 12/19/2022]
Abstract
Hypoxia in vivo induces oligozoospermia, azoospermia, and degeneration of the germinal epithelium, but the underlying molecular mechanism of this induction is not fully clarified. The aim of this study was to investigate the role of the death receptor pathway and the mitochondrial pathway in hypoxia-induced apoptosis of mouse GC-2spd (GC-2) cells and the relationship between HIF-1α and apoptosis of GC-2 cells induced by hypoxia. GC-2 cells were subjected to 1% oxygen for 48 hr. Apoptosis was detected by flow cytometry, TUNEL staining, LDH, caspase-3/8/9 in the absence and presence of HIF-1α siRNA. The protein levels of apoptosis-related markers were determined by Western blot in the presence and absence of HIF-1α siRNA. Mitochondrial transmembrane potential change was observed by in situ JC-1 staining. Cell viability was assessed upon treatment of caspase-8 and 9 inhibitors. The results indicated that hypoxia at 1% oxygen for 48 hr induced apoptosis of GC-2 cells. A prolonged exposure of GC-2 cells to hypoxic conditions caused downregulation of c-FLIP, Dc R2 and Bcl-2 and upregulation of DR5 , TRAIL, Fas, p53, and Bax, with an overproduction of caspase-3/8/9. Moreover, hypoxia at this level had an effect on mitochondrial depolarization. In addition, specific inhibitors of caspase-8/9 partially suppressed hypoxia-induced GC-2 cell apoptosis, and the anti-apoptotic effects of the caspase inhibitors were additive. Of note, HIF-1α knockdown attenuated hypoxia and induced apoptosis of GC-2 cells. In conclusion, our data suggest that the death receptor pathway and mitochondrial pathway, which are likely mediated by HIF-1α, contribute to hypoxia-induced GC-2 cell apoptosis.
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Affiliation(s)
- Jun Yin
- Department of Pathophysiology and High Altitude Pathology/Key Laboratory of High Altitude Environment Medicine (Third Military Medical University), Ministry of Education/Key Laboratory of High Altitude Medicine, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, PR China
| | - Bing Ni
- Department of Pathophysiology and High Altitude Pathology/Key Laboratory of High Altitude Environment Medicine (Third Military Medical University), Ministry of Education/Key Laboratory of High Altitude Medicine, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, PR China
| | - Wei-Gong Liao
- Department of Pathophysiology and High Altitude Pathology/Key Laboratory of High Altitude Environment Medicine (Third Military Medical University), Ministry of Education/Key Laboratory of High Altitude Medicine, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, PR China
| | - Yu-Qi Gao
- Institute of Medicine and Hygienic Equipment for High Altitude Region/Key Laboratory of High Altitude Environment Medicine (Third Military Medical University), Ministry of Education/Key Laboratory of High Altitude Medicine, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, PR China
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102
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Pérez-Salvia M, Simó-Riudalbas L, Llinàs-Arias P, Roa L, Setien F, Soler M, de Moura MC, Bradner JE, Gonzalez-Suarez E, Moutinho C, Esteller M. Bromodomain inhibition shows antitumoral activity in mice and human luminal breast cancer. Oncotarget 2017; 8:51621-51629. [PMID: 28881673 PMCID: PMC5584274 DOI: 10.18632/oncotarget.18255] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/04/2017] [Indexed: 01/25/2023] Open
Abstract
BET bromodomain inhibitors, which have an antitumoral effect against various solid cancer tumor types, have not been studied in detail in luminal breast cancer, despite the prevalence of this subtype of mammary malignancy. Here we demonstrate that the BET bromodomain inhibitor JQ1 exerts growth-inhibitory activity in human luminal breast cancer cell lines associated with a depletion of the C-MYC oncogene, but does not alter the expression levels of the BRD4 bromodomain protein. Interestingly, expression microarray analyses indicate that, upon JQ1 administration, the antitumoral phenotype also involves downregulation of relevant breast cancer oncogenes such as the Breast Carcinoma-Amplified Sequence 1 (BCAS1) and the PDZ Domain-Containing 1 (PDZK1). We have also applied these in vitro findings in an in vivo model by studying a transgenic mouse model representing the luminal B subtype of breast cancer, the MMTV-PyMT, in which the mouse mammary tumor virus promoter is used to drive the expression of the polyoma virus middle T-antigen to the mammary gland. We have observed that the use of the BET bromodomain inhibitor for the treatment of established breast neoplasms developed in the MMTV-PyMT model shows antitumor potential. Most importantly, if JQ1 is given before the expected time of tumor detection in the MMTV-PyMT mice, it retards the onset of the disease and increases the survival of these animals. Thus, our findings indicate that the use of bromodomain inhibitors is of great potential in the treatment of luminal breast cancer and merits further investigation.
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Affiliation(s)
- Montserrat Pérez-Salvia
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Laia Simó-Riudalbas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Pere Llinàs-Arias
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Laura Roa
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Fernando Setien
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Marta Soler
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Manuel Castro de Moura
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - James E Bradner
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Eva Gonzalez-Suarez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Catia Moutinho
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain.,Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), Barcelona, Catalonia, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
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103
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Small molecule selectively suppresses MYC transcription in cancer cells. Proc Natl Acad Sci U S A 2017; 114:3497-3502. [PMID: 28292893 DOI: 10.1073/pnas.1702663114] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Stauprimide is a staurosporine analog that promotes embryonic stem cell (ESC) differentiation by inhibiting nuclear localization of the MYC transcription factor NME2, which in turn results in down-regulation of MYC transcription. Given the critical role the oncogene MYC plays in tumor initiation and maintenance, we explored the potential of stauprimide as an anticancer agent. Here we report that stauprimide suppresses MYC transcription in cancer cell lines derived from distinct tissues. Using renal cancer cells, we confirmed that stauprimide inhibits NME2 nuclear localization. Gene expression analysis also confirmed the selective down-regulation of MYC target genes by stauprimide. Consistent with this activity, administration of stauprimide inhibited tumor growth in rodent xenograft models. Our study provides a unique strategy for selectively targeting MYC transcription by pharmacological means as a potential treatment for MYC-dependent tumors.
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104
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Liu Z, Wang P, Chen H, Wold EA, Tian B, Brasier AR, Zhou J. Drug Discovery Targeting Bromodomain-Containing Protein 4. J Med Chem 2017; 60:4533-4558. [PMID: 28195723 PMCID: PMC5464988 DOI: 10.1021/acs.jmedchem.6b01761] [Citation(s) in RCA: 215] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
BRD4,
the most extensively studied member of the BET family, is
an epigenetic regulator that localizes to DNA via binding to acetylated
histones and controls the expression of therapeutically important
gene regulatory networks through the recruitment of transcription
factors to form mediator complexes, phosphorylating RNA polymerase
II, and by its intrinsic histone acetyltransferase activity. Disrupting
the protein–protein interactions between BRD4 and acetyl-lysine
has been shown to effectively block cell proliferation in cancer,
cytokine production in acute inflammation, and so forth. To date,
significant efforts have been devoted to the development of BRD4 inhibitors,
and consequently, a dozen have progressed to human clinical trials.
Herein, we summarize the advances in drug discovery and development
of BRD4 inhibitors by focusing on their chemotypes, in vitro and in
vivo activity, selectivity, relevant mechanisms of action, and therapeutic
potential. Opportunities and challenges to achieve selective and efficacious
BRD4 inhibitors as a viable therapeutic strategy for human diseases
are also highlighted.
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Affiliation(s)
- Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Eric A Wold
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Bing Tian
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Allan R Brasier
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, ‡Department of Internal Medicine, §Sealy Center for Molecular Medicine, ξInstitute for Translational Sciences, University of Texas Medical Branch , Galveston, Texas 77555, United States
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105
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AR Signaling in Breast Cancer. Cancers (Basel) 2017; 9:cancers9030021. [PMID: 28245550 PMCID: PMC5366816 DOI: 10.3390/cancers9030021] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/13/2017] [Accepted: 02/18/2017] [Indexed: 12/31/2022] Open
Abstract
Androgen receptor (AR, a member of the steroid hormone receptor family) status has become increasingly important as both a prognostic marker and potential therapeutic target in breast cancer. AR is expressed in up to 90% of estrogen receptor (ER) positive breast cancer, and to a lesser degree, human epidermal growth factor 2 (HER2) amplified tumors. In the former, AR signaling has been correlated with a better prognosis given its inhibitory activity in estrogen dependent disease, though conversely has also been shown to increase resistance to anti-estrogen therapies such as tamoxifen. AR blockade can mitigate this resistance, and thus serves as a potential target in ER-positive breast cancer. In HER2 amplified breast cancer, studies are somewhat conflicting, though most show either no effect or are associated with poorer survival. Much of the available data on AR signaling is in triple-negative breast cancer (TNBC), which is an aggressive disease with inferior outcomes comparative to other breast cancer subtypes. At present, there are no approved targeted therapies in TNBC, making study of the AR signaling pathway compelling. Gene expression profiling studies have also identified a luminal androgen receptor (LAR) subtype that is dependent on AR signaling in TNBC. Regardless, there seems to be an association between AR expression and improved outcomes in TNBC. Despite lower pathologic complete response (pCR) rates with neoadjuvant therapy, patients with AR-expressing TNBC have been shown to have a better prognosis than those that are AR-negative. Clinical studies targeting AR have shown somewhat promising results. In this paper we review the literature on the biology of AR in breast cancer and its prognostic and predictive roles. We also present our thoughts on therapeutic strategies.
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106
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Aird F, Kandela I, Mantis C. Replication Study: BET bromodomain inhibition as a therapeutic strategy to target c-Myc. eLife 2017; 6. [PMID: 28100400 PMCID: PMC5245966 DOI: 10.7554/elife.21253] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 11/22/2016] [Indexed: 12/16/2022] Open
Abstract
In 2015, as part of the Reproducibility Project: Cancer Biology, we published a Registered Report (Kandela et al., 2015) that described how we intended to replicate selected experiments from the paper "BET bromodomain inhibition as a therapeutic strategy to target c-Myc" (Delmore et al., 2011). Here we report the results of those experiments. We found that treatment of human multiple myeloma (MM) cells with the small-molecular inhibitor of BET bromodomains, (+)-JQ1, selectively downregulated MYC transcription, which is similar to what was reported in the original study (Figure 3B; Delmore et al., 2011). Efficacy of (+)-JQ1 was evaluated in an orthotopically xenografted model of MM. Overall survival was increased in (+)-JQ1 treated mice compared to vehicle control, similar to the original study (Figure 7E; Delmore et al., 2011). Tumor burden, as determined by bioluminescence, was decreased in (+)-JQ1 treated mice compared to vehicle control; however, while the effect was in the same direction as the original study (Figure 7C-D; Delmore et al., 2011), it was not statistically significant. The opportunity to detect a statistically significant difference was limited though, due to the higher rate of early death in the control group, and increased overall survival in (+)-JQ1 treated mice before the pre-specified tumor burden analysis endpoint. Additionally, we evaluated the (−)-JQ1 enantiomer that is structurally incapable of inhibiting BET bromodomains, which resulted in a minimal impact on MYC transcription, but did not result in a statistically significant difference in tumor burden or survival distributions compared to treatment with (+)-JQ1. Finally, we report meta-analyses for each result. DOI:http://dx.doi.org/10.7554/eLife.21253.001
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Affiliation(s)
- Fraser Aird
- Developmental Therapeutics Core, Northwestern University, Evanston, United States
| | - Irawati Kandela
- Developmental Therapeutics Core, Northwestern University, Evanston, United States
| | - Christine Mantis
- Developmental Therapeutics Core, Northwestern University, Evanston, United States
| | -
- Developmental Therapeutics Core, Northwestern University, Evanston, United States
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107
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Shu S, Polyak K. BET Bromodomain Proteins as Cancer Therapeutic Targets. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 81:123-129. [PMID: 28062533 DOI: 10.1101/sqb.2016.81.030908] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Epigenetic regulators are emerging therapeutic targets in a wide variety of human cancers. BET bromodomain proteins have been identified as key regulators of oncogenic transcription factors including MYC; therefore, their inhibition might provide a way to block these "undruggable" targets. Several BET bromodomain inhibitors are in clinical development with promising preliminary findings. However, tumors acquire resistance to these agents in several different ways. In this review, we summarize the role that BET bromodomain proteins play in tumorigenesis as well as the molecular mechanisms underlying therapeutic responses and resistance to their inhibition with emphasis on BRD4 and breast cancer.
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Affiliation(s)
- Shaokun Shu
- Department of Medical Oncology, Dana-Farber Cancer Institute; Department of Medicine, Brigham and Women's Hospital; and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215
| | - Kornelia Polyak
- Department of Medical Oncology, Dana-Farber Cancer Institute; Department of Medicine, Brigham and Women's Hospital; and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215
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108
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Ivanov DP, Grabowska AM, Garnett MC. High-Throughput Spheroid Screens Using Volume, Resazurin Reduction, and Acid Phosphatase Activity. Methods Mol Biol 2017; 1601:43-59. [PMID: 28470516 DOI: 10.1007/978-1-4939-6960-9_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mainstream adoption of physiologically relevant three-dimensional models has been slow in the last 50 years due to long, manual protocols with poor reproducibility, high price, and closed commercial platforms. This chapter describes high-throughput, low-cost, open methods for spheroid viability assessment which use readily available reagents and open-source software to analyze spheroid volume, metabolism, and enzymatic activity. We provide two ImageJ macros for automated spheroid size determination-for both single images and images in stacks. We also share an Excel template spreadsheet allowing users to rapidly process spheroid size data, analyze plate uniformity (such as edge effects and systematic seeding errors), detect outliers, and calculate dose-response. The methods would be useful to researchers in preclinical and translational research planning to move away from simplistic monolayer studies and explore 3D spheroid screens for drug safety and efficacy without substantial investment in money or time.
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Affiliation(s)
- Delyan P Ivanov
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK.
| | - Anna M Grabowska
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
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109
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Abstract
Aberrations in the epigenetic landscape are a hallmark of cancer. Alterations in enzymes that are “writers,” “erasers,” or “readers” of histone modification marks are common. Bromodomains are “readers” that bind acetylated lysines in histone tails. Their most important function is the regulation of gene transcription by the recruitment of different molecular partners. Moreover, proteins containing bromodomains are also epigenetic regulators, although little is known about the specific function of these domains. In recent years, there has been increasing interest in developing small molecules that can target specific bromodomains. First, this has helped clarify biological functions of bromodomain-containing proteins. Secondly, it opens a new front for combatting cancer. In this review we will describe the structures and mechanisms associated with Bromodomain and Extra-Terminal motif (BET) inhibitors and non-BET inhibitors, their current status of development, and their promising role as anti-cancer agents.
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Affiliation(s)
- Montserrat Pérez-Salvia
- a Cancer Epigenetics and Biology Program (PEBC) , Bellvitge Biomedical Research Institute (IDIBELL) , Barcelona , Catalonia , Spain
| | - Manel Esteller
- a Cancer Epigenetics and Biology Program (PEBC) , Bellvitge Biomedical Research Institute (IDIBELL) , Barcelona , Catalonia , Spain.,b Department of Physiological Sciences II, School of Medicine , University of Barcelona , Barcelona , Catalonia , Spain.,c Institució Catalana de Recerca i Estudis Avançats (ICREA) , Barcelona , Catalonia , Spain
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