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Geng H, Xue C, Mendonca J, Sun XX, Liu Q, Reardon PN, Chen Y, Qian K, Hua V, Chen A, Pan F, Yuan J, Dang S, Beer TM, Dai MS, Kachhap SK, Qian DZ. Interplay between hypoxia and androgen controls a metabolic switch conferring resistance to androgen/AR-targeted therapy. Nat Commun 2018; 9:4972. [PMID: 30478344 PMCID: PMC6255907 DOI: 10.1038/s41467-018-07411-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
Despite recent advances, the efficacy of androgen/androgen receptor (AR)-targeted therapy remains limited for many patients with metastatic prostate cancer. This is in part because prostate cancers adaptively switch to the androgen/AR-independent pathway for survival and growth, thereby conferring therapy resistance. Tumor hypoxia is considered as a major cause of treatment resistance. However, the exact mechanism is largely unclear. Here we report that chronic-androgen deprivation therapy (ADT) in the condition of hypoxia induces adaptive androgen/AR-independence, and therefore confers resistance to androgen/AR-targeted therapy, e.g., enzalutamide. Mechanistically, this is mediated by glucose-6-phosphate isomerase (GPI), which is transcriptionally repressed by AR in hypoxia, but restored and increased by AR inhibition. In turn, GPI maintains glucose metabolism and energy homeostasis in hypoxia by redirecting the glucose flux from androgen/AR-dependent pentose phosphate pathway (PPP) to hypoxia-induced glycolysis pathway, thereby reducing the growth inhibitory effect of enzalutamide. Inhibiting GPI overcomes the therapy resistance in hypoxia in vitro and increases enzalutamide efficacy in vivo.
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Affiliation(s)
- Hao Geng
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Changhui Xue
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Janet Mendonca
- Johns Hopkins Kimmel Cancer Center, 401 N Broadway, Baltimore, MD, 21287, USA
| | - Xiao-Xin Sun
- Department of Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Qiong Liu
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Patrick N Reardon
- NMR Core facility, Oregon State University, Corvallis, OR, 97331, USA
| | - Yingxiao Chen
- Department of Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Kendrick Qian
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Vivian Hua
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Alice Chen
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Freddy Pan
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Julia Yuan
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Sang Dang
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Tomasz M Beer
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
- Division of Hematology & Medical Oncology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Mu-Shui Dai
- Department of Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Sushant K Kachhap
- Johns Hopkins Kimmel Cancer Center, 401 N Broadway, Baltimore, MD, 21287, USA
| | - David Z Qian
- OHSU Knight Cancer Institute, Prostate Cancer Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
- Division of Hematology & Medical Oncology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
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Btg2 is a Negative Regulator of Cardiomyocyte Hypertrophy through a Decrease in Cytosolic RNA. Sci Rep 2016; 6:28592. [PMID: 27346836 PMCID: PMC4921833 DOI: 10.1038/srep28592] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/06/2016] [Indexed: 12/27/2022] Open
Abstract
Under hypertrophic stimulation, cardiomyocytes enter a hypermetabolic state and accelerate biomass accumulation. Although the molecular pathways that regulate protein levels are well-studied, the functional implications of RNA accumulation and its regulatory mechanisms in cardiomyocytes remain elusive. Here, we have elucidated the quantitative kinetics of RNA in cardiomyocytes through single cell imaging and c-Myc (Myc)-mediated hypermetabolic analytical model using cultured cardiomyocytes. Nascent RNA labeling combined with single cell imaging demonstrated that Myc protein significantly increased the amount of global RNA production per cardiomyocyte. Chromatin immunoprecipitation with high-throughput sequencing clarified that overexpressed Myc bound to a specific set of genes and recruits RNA polymerase II. Among these genes, we identified Btg2 as a novel target of Myc. Btg2 overexpression significantly reduced cardiomyocyte surface area. Conversely, shRNA-mediated knockdown of Btg2 accelerated adrenergic stimulus-induced hypertrophy. Using mass spectrometry analysis, we determined that Btg2 binds a series of proteins that comprise mRNA deadenylation complexes. Intriguingly, Btg2 specifically suppresses cytosolic, but not nuclear, RNA levels. Btg2 knockdown further enhances cytosolic RNA accumulation in cardiomyocytes under adrenergic stimulation, suggesting that Btg2 negatively regulates reactive hypertrophy by negatively regulating RNA accumulation. Our findings provide insight into the functional significance of the mechanisms regulating RNA levels in cardiomyocytes.
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