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Zhang S, You X, Zheng Y, Shen Y, Xiong X, Sun Y. The UBE2C/CDH1/DEPTOR axis is an oncogene and tumor suppressor cascade in lung cancer cells. J Clin Invest 2023; 133:162434. [PMID: 36548081 PMCID: PMC9927933 DOI: 10.1172/jci162434] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Ubiquitin-conjugating enzyme E2C (UBE2C) mediates ubiquitylation chain formation via the K11 linkage. While previous in vitro studies showed that UBE2C plays a growth-promoting role in cancer cell lines, the underlying mechanism remains elusive. Still unknown is whether and how UBE2C plays a promoting role in vivo. Here we report that UBE2C was indeed essential for growth and survival of lung cancer cells harboring Kras mutations, and UBE2C was required for KrasG12D-induced lung tumorigenesis, since Ube2c deletion significantly inhibited tumor formation and extended the lifespan of mice. Mechanistically, KrasG12D induced expression of UBE2C, which coupled with APC/CCDH1 E3 ligase to promote ubiquitylation and degradation of DEPTOR, leading to activation of mTORC signaling. Importantly, DEPTOR levels fluctuated during cell cycle progression in a manner dependent on UBE2C and CDH1, indicating their physiological connection. Finally, Deptor deletion fully rescued the tumor inhibitory effect of Ube2c deletion in the KrasG12D lung tumor model, indicating a causal role of Deptor. Taken together, our study shows that the UBE2C/CDH1/DEPTOR axis forms an oncogene and tumor suppressor cascade that regulates cell cycle progression and autophagy and validates UBE2C an attractive target for lung cancer associated with Kras mutations.
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Affiliation(s)
- Shizhen Zhang
- Cancer Institute and.,Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, the Second Affiliated Hospital, and
| | - Xiahong You
- Cancer Institute and.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yawen Zheng
- Cancer Institute and.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yanwen Shen
- Cancer Institute and.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiufang Xiong
- Cancer Institute and.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Sun
- Cancer Institute and.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China.,Research Center for Life Science and Human Health, Binjiang Institute of Zhejiang University, Hangzhou, China
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2
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Davis AR, Goodenough CG, Westerlind KC, Strange R, Deaver JW, Ryan PJ, Riechman SE, Fluckey JD. Myokines derived from contracting skeletal muscle suppress anabolism in MCF7 breast cancer cells by inhibiting mTOR. Front Physiol 2022; 13:1033585. [PMID: 36388131 PMCID: PMC9644210 DOI: 10.3389/fphys.2022.1033585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/06/2022] [Indexed: 08/27/2023] Open
Abstract
There is strong evidence that physical activity has a profound protective effect against multiple types of cancer. Here, we show that this effect may be mediated by factors released from skeletal muscle during simulated exercise, in situ, which suppress canonical anabolic signaling in breast cancer. We report attenuated growth of MCF7 breast cancer cells in the presence of a rodent-derived exercise conditioned perfusate, independent of prior exercise training. This reduction was concomitant with increased levels of DEPTOR protein and reduced mTOR activity.
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Affiliation(s)
- Amanda R. Davis
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
| | - Chelsea G. Goodenough
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
| | - Kim C. Westerlind
- University of Colorado Health Sciences Center, Denver, CO, United States
| | - Robert Strange
- University of Colorado Health Sciences Center, Denver, CO, United States
| | - John W. Deaver
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
| | - Patrick J. Ryan
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
| | - Steven E. Riechman
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
| | - James D. Fluckey
- Texas A&M University, School of Education and Human Development, College Station, TX, United States
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3
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Guo J, Yu J, Mu M, Chen Z, Xu Z, Zhao C, Yang K, Zheng J, Qin X, Zhao W, Sun X. DFNA5 inhibits colorectal cancer proliferation by suppressing the mTORC1/2 signaling pathways via upregulation of DEPTOR. Cell Cycle 2022; 21:2165-2178. [PMID: 35923131 PMCID: PMC9518992 DOI: 10.1080/15384101.2022.2088570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The human deafness, autosomal dominant 5 gene (DFNA5), a newly discovered executor of pyroptosis, has been strongly implicated in the tumorigenesis of several human cancers. However, an understanding of the functional role of DFNA5 in the development and progression of colorectal cancer (CRC) is limited. In this study, we demonstrated that DFNA5 was downregulated in CRC tissues. Ectopic expression of DFNA5 inhibited tumor cell growth in vitro, retarded tumor formation in vivo, and blocked a cell-cycle transition from the G0/G1 to the S phase, whereas a DFNA5 knockdown promoted cell proliferation. Western blotting showed that the levels of cell cycle-related proteins, including cyclin D1, cyclin E, CDK2, and p21, were accordingly altered upon DFNA5 overexpression or DFNA5 knockdown. Mechanistic studies indicated that DFNA5 exerted its tumor suppressor functions by antagonizing mTORC1/2 signaling via upregulation of DEPTOR. In addition, blockage of mTORC1/2 signaling by Torin-1 abolished the accelerative proliferation by DFNA5 knockdown. In conclusion, these results indicated that DFNA5 inhibits the proliferation and tumor formation of colon cancer cells by suppressing mTORC1/2 signaling.
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Affiliation(s)
- Jing Guo
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Junhui Yu
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Mingchao Mu
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zilu Chen
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zhengshui Xu
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Chenye Zhao
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Kui Yang
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Jianbao Zheng
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Xiao Qin
- Department of Emergency, Ankang People's Hospital, Ankang, Shaanxi, China
| | - Wei Zhao
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Xuejun Sun
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
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4
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Sadria M, Seo D, Layton AT. The mixed blessing of AMPK signaling in Cancer treatments. BMC Cancer 2022; 22:105. [PMID: 35078427 PMCID: PMC8786626 DOI: 10.1186/s12885-022-09211-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
Background Nutrient acquisition and metabolism pathways are altered in cancer cells to meet bioenergetic and biosynthetic demands. A major regulator of cellular metabolism and energy homeostasis, in normal and cancer cells, is AMP-activated protein kinase (AMPK). AMPK influences cell growth via its modulation of the mechanistic target of Rapamycin (mTOR) pathway, specifically, by inhibiting mTOR complex mTORC1, which facilitates cell proliferation, and by activating mTORC2 and cell survival. Given its conflicting roles, the effects of AMPK activation in cancer can be counter intuitive. Prior to the establishment of cancer, AMPK acts as a tumor suppressor. However, following the onset of cancer, AMPK has been shown to either suppress or promote cancer, depending on cell type or state. Methods To unravel the controversial roles of AMPK in cancer, we developed a computational model to simulate the effects of pharmacological maneuvers that target key metabolic signalling nodes, with a specific focus on AMPK, mTORC, and their modulators. Specifically, we constructed an ordinary differential equation-based mechanistic model of AMPK-mTORC signaling, and parametrized the model based on existing experimental data. Results Model simulations were conducted to yield the following predictions: (i) increasing AMPK activity has opposite effects on mTORC depending on the nutrient availability; (ii) indirect inhibition of AMPK activity through inhibition of sirtuin 1 (SIRT1) only has an effect on mTORC activity under conditions of low nutrient availability; (iii) the balance between cell proliferation and survival exhibits an intricate dependence on DEP domain-containing mTOR-interacting protein (DEPTOR) abundance and AMPK activity; (iv) simultaneous direct inhibition of mTORC2 and activation of AMPK is a potential strategy for suppressing both cell survival and proliferation. Conclusions Taken together, model simulations clarify the competing effects and the roles of key metabolic signalling pathways in tumorigenesis, which may yield insights on innovative therapeutic strategies. Supplementary Information The online version contains supplementary material available at 10.1186/s12885-022-09211-1.
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Heimhalt M, Berndt A, Wagstaff J, Anandapadamanaban M, Perisic O, Maslen S, McLaughlin S, Yu CWH, Masson GR, Boland A, Ni X, Yamashita K, Murshudov GN, Skehel M, Freund SM, Williams RL. Bipartite binding and partial inhibition links DEPTOR and mTOR in a mutually antagonistic embrace. eLife 2021; 10:e68799. [PMID: 34519269 PMCID: PMC8439657 DOI: 10.7554/elife.68799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/31/2021] [Indexed: 12/16/2022] Open
Abstract
The mTORC1 kinase complex regulates cell growth, proliferation, and survival. Because mis-regulation of DEPTOR, an endogenous mTORC1 inhibitor, is associated with some cancers, we reconstituted mTORC1 with DEPTOR to understand its function. We find that DEPTOR is a unique partial mTORC1 inhibitor that may have evolved to preserve feedback inhibition of PI3K. Counterintuitively, mTORC1 activated by RHEB or oncogenic mutation is much more potently inhibited by DEPTOR. Although DEPTOR partially inhibits mTORC1, mTORC1 prevents this inhibition by phosphorylating DEPTOR, a mutual antagonism that requires no exogenous factors. Structural analyses of the mTORC1/DEPTOR complex showed DEPTOR's PDZ domain interacting with the mTOR FAT region, and the unstructured linker preceding the PDZ binding to the mTOR FRB domain. The linker and PDZ form the minimal inhibitory unit, but the N-terminal tandem DEP domains also significantly contribute to inhibition.
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Affiliation(s)
- Maren Heimhalt
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Alex Berndt
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Jane Wagstaff
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Olga Perisic
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Sarah Maslen
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | | | - Glenn R Masson
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Andreas Boland
- Department of Molecular Biology, University of GenevaGenevaSwitzerland
| | - Xiaodan Ni
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | | | - Mark Skehel
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
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6
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Gong L, Shu J, Chen X, Pan H, Chen G, Bi Y, Cui D, Li X, Liu D, Wang L, Wang Y, Liu P, Xiong X, Zhao Y. DEPTOR inhibits lung tumorigenesis by inactivating the EGFR-mTOR signals. Cancer Lett 2021; 519:263-276. [PMID: 34320372 DOI: 10.1016/j.canlet.2021.07.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 01/22/2023]
Abstract
DEPTOR plays vital roles in the regulation of cell proliferation and survival by directly modulating the activity of mTORC1/2. However, the physiological role of DEPTOR in lung tumorigenesis, as well as its clinical significance, remains elusive. In this study, we revealed that decreased DEPTOR expression correlated with increased tumor size, poor differentiation, and worse survival in patients with lung cancer. DEPTOR depletion promoted cell proliferation, survival, migration, and invasion in human lung cancer cells. Mechanistically, DEPTOR bound to the kinase domain of EGFR via its PDZ domain to inactivate EGFR signal. Thus, DEPTOR depletion not only directly activated mTORC1/2, but also relieved the inhibition of EGFR to subsequently activate mTOR signals, leading to the induction of cell proliferation and survival. Additionally, activated EGFR-mTOR signals upregulated the expression of ZEB1 and SLUG to induce epithelial-mesenchymal transition, resulting in enhanced migration and invasion. Importantly, Deptor deletion accelerated KrasG12D;p53fl/fl-induced lung tumorigenesis and shortened mouse life span via the activation of EGFR-mTOR signals. Collectively, our study demonstrated that DEPTOR acts as a tumor suppressor in lung tumorigenesis, and its reduction may advance the progression of human lung cancer.
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Affiliation(s)
- Longyuan Gong
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianfeng Shu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoyu Chen
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China; Department of Medical Oncology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hui Pan
- Department of Lung Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Guoan Chen
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Yanli Bi
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Danrui Cui
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xufan Li
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Dian Liu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Linchen Wang
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yue Wang
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Pengyuan Liu
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiufang Xiong
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China; Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Yongchao Zhao
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China; Cancer Center, Zhejiang University, Hangzhou, China.
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7
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Xia W, Gong D, Qin X, Cai Z. [MicroRNA-671-3p suppresses proliferation and invasion of breast cancer cells by targeting DEPTOR]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2020; 40:42-48. [PMID: 32376551 DOI: 10.12122/j.issn.1673-4254.2020.01.07] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To investigate the effects of miR-671-3p on the proliferation and invasion of breast cancer cells and explore the possible mechanism. METHODS We examined the expressions of miR-671-3p in human normal epithelial cells (MCF-10A) and breast cancer cell lines (MCF-7, MDA-MB-231, and SK-BR3) using RT-PCR. The effects of transfection with a miR-671-3p mimic or inhibitor on the proliferation, migration and invasion of MCF-7 cells were evaluated using CCK-8 assay and Transwell chamber assay. The target gene of miR-671-3p was predicated with Targetscan and validated by a dual luciferase reporter system and Western blotting. RESULTS The expression of miR-671-3p was significantly lower in breast cancer cells than in normal breast epithelial cells. Compared with negative control group, MCF-7 cells with miR-671-3p overexpression exhibited significantly reduced proliferation and invasion, whereas inhibition of miR-671-3p obviously promoted the cell proliferation and invasion. Luciferase reporter assay demonstrated that DEPTOR was the target gene of miR-671-3p, and miR-671-3p overexpression caused significant down-regulation of the protein expression of DEPTOR. CONCLUSIONS MiR-671-3p suppresses the proliferation and invasion of breast cancer cell line MCF-7 by directly targeting DEPTOR protein.
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Affiliation(s)
- Wei Xia
- Department of Cell biology, Southern Medical University, Guangzhou 510515, China.,Department of Clinical Laboratory, 74th Army Hospital of PLA, Guangzhou 510310, China
| | - Degui Gong
- Department of Clinical Laboratory, 74th Army Hospital of PLA, Guangzhou 510310, China
| | - Xiaoping Qin
- Department of Clinical Laboratory, 74th Army Hospital of PLA, Guangzhou 510310, China
| | - Zhuo Cai
- Department of Pharmacy, Air Force Hospital of Southern Theater Command of PLA, Guangzhou 510602, China
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DEPTOR is an in vivo tumor suppressor that inhibits prostate tumorigenesis via the inactivation of mTORC1/2 signals. Oncogene 2019; 39:1557-1571. [PMID: 31685947 PMCID: PMC7018663 DOI: 10.1038/s41388-019-1085-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 01/06/2023]
Abstract
The DEPTOR-mTORC1/2 axis has been shown to play an important, but a context dependent role in the regulation of proliferation and the survival of various cancer cells in cell culture settings. The in vivo role of DEPTOR in tumorigenesis remains elusive. Here we showed that the levels of both DEPTOR protein and mRNA were substantially decreased in human prostate cancer tissues, which positively correlated with disease progression. DEPTOR depletion accelerated proliferation and survival, migration, and invasion in human prostate cancer cells. Mechanistically, DEPTOR depletion not only activated both mTORC1 and mTORC2 signals to promote cell proliferation and survival, but also induced an AKT-dependent epithelial–mesenchymal transition (EMT) and β-catenin nuclear translocation to promote cell migration and invasion. Abrogation of mTOR or AKT activation rescued the biological consequences of DEPTOR depletion. Importantly, in a Deptor-KO mouse model, Deptor knockout accelerated prostate tumorigenesis triggered by Pten loss via the activation of mTOR signaling. Collectively, our study demonstrates that DEPTOR is a tumor suppressor in the prostate, and its depletion promotes tumorigenesis via the activation of mTORC1 and mTORC2 signals. Thus, DEPTOR reactivation via a variety of means would have therapeutic potential for the treatment of prostate cancer.
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9
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Doan H, Parsons A, Devkumar S, Selvarajah J, Miralles F, Carroll VA. HIF-mediated Suppression of DEPTOR Confers Resistance to mTOR Kinase Inhibition in Renal Cancer. iScience 2019; 21:509-520. [PMID: 31710966 PMCID: PMC6849413 DOI: 10.1016/j.isci.2019.10.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 07/26/2019] [Accepted: 10/23/2019] [Indexed: 12/13/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a fundamental regulator of cell growth, proliferation, and metabolism. mTOR is activated in renal cancer and accelerates tumor progression. Here, we report that the mTOR inhibitor, DEP domain-containing mTOR-interacting protein (DEPTOR), is strikingly suppressed in clear cell renal cell carcinoma (ccRCC) tumors and cell lines. We demonstrate that DEPTOR is repressed by both hypoxia-inducible factors, HIF-1 and HIF-2, which occurs through activation of the HIF-target gene and transcriptional repressor, BHLHe40/DEC1/Stra13. Restoration of DEPTOR- and CRISPR/Cas9-mediated knockout experiments demonstrate that DEPTOR is growth inhibitory in ccRCC. Furthermore, loss of DEPTOR confers resistance to second-generation mTOR kinase inhibitors through deregulated mTORC1 feedback to IRS-2/PI3K/Akt. This work reveals a hitherto unknown mechanism of resistance to mTOR kinase targeted therapy that is mediated by HIF-dependent reprograming of mTOR/DEPTOR networks and suggests that restoration of DEPTOR in ccRCC will confer sensitivity to mTOR kinase therapeutics.
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Affiliation(s)
- Hong Doan
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Alexander Parsons
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Shruthi Devkumar
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK; Centre for Biomedical Education, Institute of Medical and Biomedical Education, St George's, University of London, London SW17 0RE, UK
| | - Jogitha Selvarajah
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK; Centre for Biomedical Education, Institute of Medical and Biomedical Education, St George's, University of London, London SW17 0RE, UK
| | - Francesc Miralles
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK; Centre for Biomedical Education, Institute of Medical and Biomedical Education, St George's, University of London, London SW17 0RE, UK
| | - Veronica A Carroll
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK; Centre for Biomedical Education, Institute of Medical and Biomedical Education, St George's, University of London, London SW17 0RE, UK.
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10
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Yao H, Tang H, Zhang Y, Zhang QF, Liu XY, Liu YT, Gu WT, Zheng YZ, Shang HB, Wang Y, Huang JY, Wei YX, Zhang X, Zhang J, Wu ZB. DEPTOR inhibits cell proliferation and confers sensitivity to dopamine agonist in pituitary adenoma. Cancer Lett 2019; 459:135-144. [PMID: 31176743 DOI: 10.1016/j.canlet.2019.05.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/23/2019] [Accepted: 05/31/2019] [Indexed: 01/20/2023]
Abstract
DEP domain-containing mechanistic target of rapamycin (mTOR)-interacting protein (DEPTOR) is an important modulator of mTOR, a highly conserved kinase whose hyperactivation is critically involved in a variety of human tumors. The role of DEPTOR playing in pituitary adenoma (PA) is largely unknown. Here, we reported that DEPTOR was downregulated in PA tissues, especially dopamine-resistant prolactinomas. Consistently, overexpression of DEPTOR inhibited pituitary tumor GH3 and MMQ cells proliferation in vitro and in vivo, and sensitized GH3 and MMQ cells to cabergoline (CAB), a dopamine agonist (DA). Conversely, knockdown of DEPTOR promoted GH3 and MMQ cells proliferation, and conferred cells resistance to CAB. Mechanistically, DEPTOR inhibited both mTOR Complex 1 (mTORC1) and 2 (mTORC2) activities in PA cells. In addition, DEPTOR expression level was increased to suppress mTOR kinase activity via decreasing E3 ubiquitin ligase, βTrCP1, in response to CAB. Furthermore, DEPTOR enhanced autophagy-dependent cell death to confer cells sensitivity to CAB. Taken together, our results suggest that DEPTOR may be a potential target for the treatment of PAs.
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Affiliation(s)
- Hong Yao
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hao Tang
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yong Zhang
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiu Fen Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Medicinal Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin Yi Liu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Medicinal Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Ting Liu
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Wei Ting Gu
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yong Zhi Zheng
- Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Han Bing Shang
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Wang
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin Yan Huang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yong Xu Wei
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xun Zhang
- Neuroendocrine Research Laboratory, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Medicinal Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Zhe Bao Wu
- Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
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Caron A, Briscoe DM, Richard D, Laplante M. DEPTOR at the Nexus of Cancer, Metabolism, and Immunity. Physiol Rev 2018; 98:1765-1803. [PMID: 29897294 DOI: 10.1152/physrev.00064.2017] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
DEP domain-containing mechanistic target of rapamycin (mTOR)-interacting protein (DEPTOR) is an important modulator of mTOR, a kinase at the center of two important protein complexes named mTORC1 and mTORC2. These highly studied complexes play essential roles in regulating growth, metabolism, and immunity in response to mitogens, nutrients, and cytokines. Defects in mTOR signaling have been associated with the development of many diseases, including cancer and diabetes, and approaches aiming at modulating mTOR activity are envisioned as an attractive strategy to improve human health. DEPTOR interaction with mTOR represses its kinase activity and rewires the mTOR signaling pathway. Over the last years, several studies have revealed key roles for DEPTOR in numerous biological and pathological processes. Here, we provide the current state of the knowledge regarding the cellular and physiological functions of DEPTOR by focusing on its impact on the mTOR pathway and its role in promoting health and disease.
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Affiliation(s)
- Alexandre Caron
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center , Dallas, Texas ; Transplant Research Program, Boston Children's Hospital , Boston, Massachusetts ; Department of Pediatrics, Harvard Medical School , Boston, Massachusetts ; Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), Faculté de Médecine, Université Laval , Québec , Canada ; and Centre de Recherche sur le Cancer de l'Université Laval, Université Laval , Québec , Canada
| | - David M Briscoe
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center , Dallas, Texas ; Transplant Research Program, Boston Children's Hospital , Boston, Massachusetts ; Department of Pediatrics, Harvard Medical School , Boston, Massachusetts ; Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), Faculté de Médecine, Université Laval , Québec , Canada ; and Centre de Recherche sur le Cancer de l'Université Laval, Université Laval , Québec , Canada
| | - Denis Richard
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center , Dallas, Texas ; Transplant Research Program, Boston Children's Hospital , Boston, Massachusetts ; Department of Pediatrics, Harvard Medical School , Boston, Massachusetts ; Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), Faculté de Médecine, Université Laval , Québec , Canada ; and Centre de Recherche sur le Cancer de l'Université Laval, Université Laval , Québec , Canada
| | - Mathieu Laplante
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center , Dallas, Texas ; Transplant Research Program, Boston Children's Hospital , Boston, Massachusetts ; Department of Pediatrics, Harvard Medical School , Boston, Massachusetts ; Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), Faculté de Médecine, Université Laval , Québec , Canada ; and Centre de Recherche sur le Cancer de l'Université Laval, Université Laval , Québec , Canada
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12
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Hu B, Shi D, Lv X, Wu F, Chen S, Shao Z. Prognostic and clinicopathological significance of DEPTOR expression in cancer patients: a meta-analysis. Onco Targets Ther 2018; 11:5083-5092. [PMID: 30174446 PMCID: PMC6110285 DOI: 10.2147/ott.s167355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background DEP domain containing mammalian target of rapamycin (mTOR)-interacting protein (DEPTOR), a recently discovered endogenous inhibitor of mTOR, has been found to be abnormally expressed in various tumors. Recent studies have demonstrated that DEPTOR could serve as a potential prognostic biomarker in several kinds of cancer. However, the prognostic value of DEPTOR is still controversial so far. Patients and methods PubMed, Embase and Web of Science were systematically searched to obtain all relevant articles about the prognostic value of DEPTOR in cancer patients. ORs or HRs with corresponding 95% CIs were pooled to estimate the association between DEP-TOR expression and the clinicopathological characteristics or survival of cancer patients. Results A total of nine eligible studies with 974 cancer patients were included in our meta-analysis. Our results demonstrated that the expression of DEPTOR was not associated with the overall survival (OS) (pooled HR=0.795, 95% CI=0.252-2.509) and event-free survival (EFS) (pooled HR=1.244, 95% CI=0.543-2.848) in cancer patients. Furthermore, subgroup analysis divided by sample size, type of cancer, Newcastle-Ottawa Scale (NOS) score and evaluation of DEPTOR expression showed identical prognostic value. In addition, our analysis also revealed that there was no significant association between expression level of DEPTOR and clinicopathological characteristics, such as tumor stage, lymph node metastasis, differentiation grade and gender. Conclusion Our meta-analysis suggested that despite the fact that DEPTOR could be overexpressed or downregulated in cancer patients, it might not be a potential marker to predict the prognosis of cancer patients.
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Affiliation(s)
- Binwu Hu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
| | - Deyao Shi
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
| | - Xiao Lv
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
| | - Fashuai Wu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
| | - Songfeng Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zengwu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
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13
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Srinivas KP, Viji R, Dan VM, Sajitha IS, Prakash R, Rahul PV, Santhoshkumar TR, Lakshmi S, Pillai MR. DEPTOR promotes survival of cervical squamous cell carcinoma cells and its silencing induces apoptosis through downregulating PI3K/AKT and by up-regulating p38 MAP kinase. Oncotarget 2018; 7:24154-71. [PMID: 26992219 PMCID: PMC5029691 DOI: 10.18632/oncotarget.8131] [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] [Received: 02/08/2016] [Accepted: 03/02/2016] [Indexed: 12/26/2022] Open
Abstract
DEPTOR is an endogenous inhibitor of mTOR complexes, de-regulated in cancers. The present study reveals a vital role for DEPTOR in survival of cervical squamous cell carcinoma (SCC). DEPTOR was found to be overexpressed in both cervical SCC cells and tissues and it's silencing in cervical SCC cells induced apoptosis, mainly by up-regulation of p38 MAPK and by inhibiting PI3K/AKT pathway via a feed-back inhibition from mTORC1-S6K. DEPTOR silencing resulted in reduced expression of the nitric oxide synthases iNOS and eNOS, as well as increased activation of ERK1/2 and p38 MAP kinases. Activation of AKT signaling by overexpression of constitutively active-AKT (CA-AKT) failed to overcome the apoptosis caused by DEPTOR silencing. Similarly pharmacological inhibition of ERK also failed to control apoptosis. However pharmacological inhibition of p38 MAPK rescued the cells from apoptosis, indicating the major role of p38 MAPK in cell death induced by DEPTOR silencing. DEPTOR was also found to regulate ERK1/2 in an AKT dependent manner. DEPTOR knockdown induced cell death in SiHa cells overexpressing the anti-apoptotic Bcl-2 and Bcl-xL, indicating strong survival role of DEPTOR in these cells. DEPTOR overexpression activated PI3K/AKT by relieving the negative feed-back inhibition from mTORC1-S6K. DEPTOR regulation was also observed to be independent of HPV E6/E7 oncoproteins, but it might be a molecular co-factor contributing to cervical carcinogenesis. In summary, DEPTOR is found to promote survival of cervical SCC cells and its reduction induced apoptosis via differential effects on PI3K/AKT and p38 MAPK and can be a potential target in cervical SCC.
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Affiliation(s)
| | - Remadevi Viji
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Vipin Mohan Dan
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Indira Sukumaran Sajitha
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Rajappan Prakash
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Puthan Valappil Rahul
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Thankayyan R Santhoshkumar
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695014, Kerala, India
| | - Subhadra Lakshmi
- Division of Cancer Research, Regional Cancer Centre, Thiruvananthapuram-695011, Kerala, India
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14
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Ji YM, Zhou XF, Zhang J, Zheng X, Li SB, Wei ZQ, Liu T, Cheng DL, Liu P, Song K, Tan T, Zhu H, Guo JL. DEPTOR suppresses the progression of esophageal squamous cell carcinoma and predicts poor prognosis. Oncotarget 2017; 7:14188-98. [PMID: 26893358 PMCID: PMC4924707 DOI: 10.18632/oncotarget.7420] [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: 11/19/2015] [Accepted: 01/29/2016] [Indexed: 01/14/2023] Open
Abstract
As a naturally occurring inhibitor of mTOR, accumulated evidence has suggested that DEPTOR plays a pivotal role in suppressing the progression of human malignances. However, the function of DEPTOR in the development of esophageal squamous cell carcinoma (ESCC) is still unclear. Here we report that the expression of DEPTOR is significantly reduced in tumor tissues derived from human patients with ESCC, and the downregulation of DEPTOR predicts a poor prognosis of ESCC patients. In addition, we found that the expression of DEPTOR negatively regulates the tumorigenic activities of ESCC cell lines (KYSE150, KYSE510 and KYSE190). Furthermore, ectopic DEPTOR expression caused a significant suppression of the cellular proliferation, migration and invasion of KYSE150 cells, which has the lowest expression level of DEPTOR in the three cell lines. Meanwhile, CRISPR/Cas9 mediated knockout of DEPTOR in KYSE-510 cells significantly promoted cellular proliferation, migration and invasion. In addition, in vivo assays further revealed that tumor growth was significantly inhibited in xenografts with ectopic DEPTOR expression as compared to untreated KYSE150 cells, and was markedly enhanced in DEPTOR knockout KYSE-510 cells. Biochemical studies revealed that overexpression of DEPTOR led to the suppression of AKT/mTOR pathway as evidenced by reduced phosphorylation of AKT, mTOR and downstream SGK1, indicating DEPTOR might control the progression of ESCC through AKT/mTOR signaling pathway. Thus, these findings, for the first time, demonstrated that DEPTOR inhibits the tumorigenesis of ESCC cells and might serve as a potential therapeutic target or prognostic marker for human patients with ESCC.
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Affiliation(s)
- Yan-Mei Ji
- Department of Intensive Care Unit, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Xue-Feng Zhou
- Department of Thoracic and Cardiovascular Surgery, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Jun Zhang
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Xiang Zheng
- Department of Intensive Care Unit, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Sheng-Bao Li
- Department of Gastroenterology, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Zhi-Qiang Wei
- Institute of Biomedical Research, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Tao Liu
- Department of Gastroenterology, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Dong-Liang Cheng
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Ping Liu
- Department of Pathology, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
| | - Kuncheng Song
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Tao Tan
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Hua Zhu
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jia-Long Guo
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, People's Republic of China
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15
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Hu B, Lv X, Gao F, Chen S, Wang S, Qing X, Liu J, Wang B, Shao Z. Downregulation of DEPTOR inhibits the proliferation, migration, and survival of osteosarcoma through PI3K/Akt/mTOR pathway. Onco Targets Ther 2017; 10:4379-4391. [PMID: 28932123 PMCID: PMC5598754 DOI: 10.2147/ott.s143518] [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] [Indexed: 12/26/2022] Open
Abstract
Accumulating evidence reveals that DEP-domain containing mTOR-interacting protein (DEPTOR) plays pivotal roles in the pathogenesis and progression of many tumors. However, the expression level of DEPTOR and its function in the tumorigenesis of osteosarcoma (OS) remain unknown. In this study, we conducted quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry to detect DEPTOR expression level in human OS tissues and cell lines. To assess DEPTOR function, DEPTOR siRNA was designed and transfected into OS cells, which were then used in a series of in vitro assays. Our results indicated that DEPTOR was highly expressed in some OS tissues and cell lines. DEPTOR knockdown by siRNA dramatically inhibited cell proliferation, migration, invasion, and the formation of vasculogenic mimicry in OS cells. In addition, DEPTOR knockdown induced cell cycle arrest in the G0/G1 phase and apoptosis in the OS cell lines, MG63 and MNNG/HOS. Furthermore, we found that DEPTOR knockdown notably activated mTOR and inhibited the PI3K/Akt pathway. Taken together, these results suggest that DEPTOR overexpression is necessary for the proliferation, migration, invasion, formation of vasculogenic mimicry, and survival of OS cells and may be a potential target for the treatment of OS.
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Affiliation(s)
- Binwu Hu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Lv
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Gao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Songfeng Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shangyu Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangcheng Qing
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianxiang Liu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Baichuan Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zengwu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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16
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Li H, Zhou W, Li L, Wu J, Liu X, Zhao L, Jia L, Sun Y. Inhibition of Neddylation Modification Sensitizes Pancreatic Cancer Cells to Gemcitabine. Neoplasia 2017; 19:509-518. [PMID: 28535453 PMCID: PMC5440286 DOI: 10.1016/j.neo.2017.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/07/2017] [Accepted: 04/08/2017] [Indexed: 11/27/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA with a 5-year survival rate less than 3% to 5%. Gemcitabine remains as a standard care for PDAC patients. Although protein neddylation is abnormally activated in many human cancers, whether neddylation dysregulation is involved in PDAC and whether targeting neddylation would sensitize pancreatic cancer cells to gemcitabine remain elusive. Here we report that high expression of neddylation components, NEDD8 and NAE1, are associated with poor survival of PDAC patients. Blockage of neddylation by MLN4924, a small molecule inhibitor targeting this modification, significantly sensitizes pancreatic cancer cells to gemcitabine, as evidenced by reduced growth both in monolayer culture and soft agar, reduced clonogenic survival, decreased invasion capacity, increased apoptosis, G2/M arrest, and senescence. Importantly, combinational treatment of MLN4924-gemcitabine near completely suppressed in vivo growth of pancreatic cancer cells. Mechanistically, accumulation of NOXA, a pro-apoptotic protein and ERBIN, a RAS signal inhibitor, appears to play, at least in part, a causal role in MLN4924 chemo-sensitization. Our study demonstrates that neddylation modification is a valid target for PDAC, and provides the proof-of-concept evidence for future clinical trial of MLN4924-gemcitabine combination for the treatment of pancreatic cancer patients.
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Affiliation(s)
- Hua Li
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, 4424B MS-1, 1301 Catherine Street, Ann Arbor, MI 48109, USA
| | - Weihua Zhou
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, 4424B MS-1, 1301 Catherine Street, Ann Arbor, MI 48109, USA
| | - Lihui Li
- Cancer Institute, Fudan University Shanghai Cancer Center, Collaborative Innovation Center of Cancer Medicine, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Jianfu Wu
- Cancer Institute, Fudan University Shanghai Cancer Center, Collaborative Innovation Center of Cancer Medicine, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Xiaoli Liu
- Cancer Institute, Fudan University Shanghai Cancer Center, Collaborative Innovation Center of Cancer Medicine, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Lili Zhao
- Department of Biostatistics, University of Michigan, 4424B MS-1, 1301 Catherine Street, Ann Arbor, MI 48109, USA
| | - Lijun Jia
- Oncology Institute of Traditional Chinese Medicine, Shanghai Research Institute of traditional Chinese Medicine, Shanghai 200032, China; Department of Oncology, Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
| | - Yi Sun
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, 4424B MS-1, 1301 Catherine Street, Ann Arbor, MI 48109, USA; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China.
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17
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Baldassarri M, Fallerini C, Cetta F, Ghisalberti M, Bellan C, Furini S, Spiga O, Crispino S, Gotti G, Ariani F, Paladini P, Renieri A, Frullanti E. Omic Approach in Non-smoker Female with Lung Squamous Cell Carcinoma Pinpoints to Germline Susceptibility and Personalized Medicine. Cancer Res Treat 2017; 50:356-365. [PMID: 28546520 PMCID: PMC5912139 DOI: 10.4143/crt.2017.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 04/25/2017] [Indexed: 12/11/2022] Open
Abstract
Purpose Lung cancer is strongly associated to tobacco smoking. However, global statistics estimate that in females the proportion of lung cancer cases that is unrelated to tobacco smoking reaches fifty percent, making questionable the etiology of the disease. Materials and Methods A never-smoker female with primary EGFR/KRAS/ALK-negative squamous cell carcinoma of the lung and their normal sibswere subjected to a novel integrative “omic” approach using a pedigree-based model for discovering genetic factors leading to cancer in the absence of well-known environmental trigger. A first-stepwhole-exome sequencing on tumor and normal tissue did not identify mutations in known driver genes. Building on the idea of a germline oligogenic origin of lung cancer, we performed whole-exome sequencing of DNA from patients’ peripheral blood and their unaffected sibs. Finally, RNA-sequencing analysis in tumoral and matched non-tumoral tissues was carried out in order to investigate the clonal profile and the pathogenic role of the identified variants. Results Filtering for rare variants with Combined Annotation Dependent Depletion (CADD) > 25 and potentially damaging effect, we identified rare/private germline deleterious variants in 11 cancer-associated genes, none ofwhich, except one, sharedwith the healthy sib, pinpointing to a “private” oligogenic germline signature. Noteworthy, among these, two mutated genes, namely ACACA and DEPTOR, turned to be potential targets for therapy because related to known drivers, such as BRCA1 and EGFR. Conclusion In the era of precision medicine, this report emphasizes the importance of an “omic” approach to uncover oligogenic germline signature underlying cancer development and to identify suitable therapeutic targets as well.
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Affiliation(s)
- Margherita Baldassarri
- Medical Genetics Unit, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | | | | | - Marco Ghisalberti
- Thoracic Surgery Unit, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Cristiana Bellan
- Section of Pathology, Department of Medical Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Simone Furini
- Department of Medical Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Ottavia Spiga
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Sergio Crispino
- Medical Oncology Unit, Azienda Usl Toscana Sudest, Siena, Italy
| | - Giuseppe Gotti
- Thoracic Surgery Unit, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Ariani
- Medical Genetics Unit, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Piero Paladini
- Thoracic Surgery Unit, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Alessandra Renieri
- Medical Genetics Unit, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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18
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Argininosuccinate Synthase 1-Deficiency Enhances the Cell Sensitivity to Arginine through Decreased DEPTOR Expression in Endometrial Cancer. Sci Rep 2017; 7:45504. [PMID: 28358054 PMCID: PMC5371991 DOI: 10.1038/srep45504] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/27/2017] [Indexed: 02/07/2023] Open
Abstract
Argininosuccinate synthetase 1 (ASS1) is a rate-limiting enzyme in arginine biosynthesis. Although ASS1 expression levels are often reduced in several tumors and low ASS1 expression can be a poor prognostic factor, the underlying mechanism has not been elucidated. In this study, we reveal a novel association between ASS1 and migration/invasion of endometrial tumors via regulation of mechanistic target of rapamycin complex (mTORC) 1 signaling. ASS1-knockout cells showed enhanced migration and invasion in response to arginine following arginine starvation. In ASS1-knockout cells, DEPTOR, an inhibitor of mTORC1 signal, was downregulated and mTORC1 signaling was more activated in response to arginine. ASS1 epigenetically enhanced DEPTOR expression by altering the histone methylation. Consistent with these findings, tumor cells at the invasive front of endometrioid carcinoma cases showed lower ASS1 and DEPTOR expression. Our findings suggest that ASS1 levels in each tumor cell are associated with invasion capability in response to arginine within the tumor microenvironment through mTORC1 signal regulation.
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19
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Dong X, Wang L, Han Z, Zhou L, Shan L, Ding Y, Xu W, Li J, Su Y, Cai R, Xiong G, Diao D, Dai M, Jia C, Zheng H. Different functions of DEPTOR in modulating sensitivity to chemotherapy for esophageal squamous cell carcinoma. Exp Cell Res 2017; 353:35-45. [PMID: 28267437 DOI: 10.1016/j.yexcr.2017.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 12/26/2022]
Abstract
There have been paradoxical findings regarding the expression of DEP domain-containing mTOR-interacting protein (DEPTOR) and its role in predicting prognosis in esophageal squamous cell carcinoma (ESCC). Here we show that DEPTOR expression was significantly increased in tumor tissues and predicted good survival in early stage ESCC patients but not in advanced stage patients. In vitro,our studies showed that ESCC cell lines could be classified into relatively high and low DEPTOR-expressing subgroups according to esophageal squamous epithelial cell line Het-1A.In our study, different levels of DEPTOR expression absolutely determined the response to chemotherapy. In relatively low-expressing cell lines, DEPTOR increased chemotherapy sensitivity via deactivation of the AKT pathway. In relatively high-expressing cell lines, DEPTOR increased cell survival and chemoresistance by strong feedback activation of the IRS1-PI3K-AKT-survivin pathway that occurred after downregulation of ribosomal protein S6 kinase (S6K). Collectively, our findings highlight the dichotomous nature of DEPTOR functions in modulating chemotherapy sensitivity in different ESCC cells.
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Affiliation(s)
- Xiaoying Dong
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Linlin Wang
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Zelong Han
- Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Ling Zhou
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Lanlan Shan
- Department of Health Management, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yan Ding
- Department of Health Management, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Wanfu Xu
- Department of Gastroenterology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Junmeng Li
- Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Yongchun Su
- Department of Bioinformatics, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Ruijun Cai
- Department of Thoracic surgery, Nanfang Hospital, Southern Medical University, Guangzhou510515, Guangdong, China
| | - Gang Xiong
- Department of Thoracic surgery, Nanfang Hospital, Southern Medical University, Guangzhou510515, Guangdong, China
| | - Dingwei Diao
- Department of Thoracic surgery, Nanfang Hospital, Southern Medical University, Guangzhou510515, Guangdong, China
| | - Meng Dai
- Department of Health Management, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Chunhong Jia
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.
| | - Hang Zheng
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China.
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20
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Catena V, Fanciulli M. Deptor: not only a mTOR inhibitor. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2017; 36:12. [PMID: 28086984 PMCID: PMC5237168 DOI: 10.1186/s13046-016-0484-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 12/23/2016] [Indexed: 01/09/2023]
Abstract
Deptor is an important protein that belongs to the mTORC1 and mTORC2 complexes, able to interact with mTOR and to inhibit its kinase activity. As a natural mTOR inhibitor, Deptor is involved in several molecular pathways, such as cell growth, apoptosis, autophagy and ER stress response. For this reason, Deptor seems to play an important role in controlling cellular homeostasis. Despite several recent insights characterizing Deptor functions and regulation, its complete role within cells has not yet been completely clarified. Indeed, quite recently, Deptor has been associated with chromatin, and it has been demonstrated having a role in transcriptional regulation, controlling in such way endoplasmatic reticulum activity. From all these observations it is not surprising that Deptor can behave either as an oncogene or oncosuppressor, depending on the cell- or tissue-contexts. This review highlights recent progresses made in our understanding of the many activities of Deptor, describing its transcriptional and post-transcriptional regulation in different cancer cell types. Moreover, here we discuss the possibility of using compounds able to inhibit Deptor or to disrupt its interaction with mTOR as novel approaches for cancer therapy.
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Affiliation(s)
- Valeria Catena
- SAFU, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research Area, Regina Elena National Cancer Institute, 00144, Rome, Italy.
| | - Maurizio Fanciulli
- SAFU, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research Area, Regina Elena National Cancer Institute, 00144, Rome, Italy.
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Tan M, Xu J, Siddiqui J, Feng F, Sun Y. Depletion of SAG/RBX2 E3 ubiquitin ligase suppresses prostate tumorigenesis via inactivation of the PI3K/AKT/mTOR axis. Mol Cancer 2016; 15:81. [PMID: 27955654 PMCID: PMC5153812 DOI: 10.1186/s12943-016-0567-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/06/2016] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND SAG (Sensitive to Apoptosis Gene), also known as RBX2, ROC2 or RNF7, is a RING component of CRL (Cullin-RING ligase), required for its activity. Our recent study showed that SAG/RBX2 co-operated with Kras to promote lung tumorigenesis, but antagonized Kras to inhibit skin tumorigenesis, suggesting a tissue/context dependent function of Sag. However, it is totally unknown whether and how Sag would play in prostate tumorigenesis, triggered by Pten loss. METHODS Sag and Pten double conditional knockout mice were generated and prostate specific deletion of Sag and Pten was achieved by PB4-Cre, and their effect on prostate tumorigenesis was evaluated by H&E staining. The methods of immunohistochemistry (IHC) staining and Western blotting were utilized to examine expression of various proteins in prostate cancer tissues or cell lines. The effect of SAG knockdown in proliferation, survival and migration was evaluated in two prostate cancer cell lines. The poly-ubiquitylation of PHLPP1 and DEPTOR was evaluated by both in vivo and in vitro ubiquitylation assays. RESULTS SAG is overexpressed progressively from early-to-late stage of human prostate cancer with the highest expression seen in metastatic lesion. Sag deletion inhibits prostate tumorigenesis triggered by Pten loss in a mouse model as a result of suppressed proliferation. SAG knockdown in human prostate cancer cells inhibits a) proliferation in monolayer and soft agar, b) clonogenic survival, and c) migration. SAG is an E3 ligase that promotes ubiquitylation and degradation of PHLPP1 and DEPTOR, leading to activation of the PI3K/AKT/mTOR axis, whereas SAG knockdown caused their accumulation. Importantly, growth suppression triggered by SAG knockdown was partially rescued by simultaneous knockdown of PHLPP1 or DEPTOR, suggesting their causal role. Accumulation of Phlpp1 and Deptor with corresponding inactivation of Akt/mTOR was also detected in Sag-null prostate cancer tissues. CONCLUSIONS Sag is an oncogenic cooperator of Pten-loss for prostate tumorigenesis. Targeting SAG E3 ligase may, therefore, have therapeutic value for the treatment of prostate cancer associated with Pten loss.
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Affiliation(s)
- Mingjia Tan
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, 4424B MS-1, 1301 Catherine Street, Ann Arbor, 48109, MI, USA
| | - Jie Xu
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, 4424B MS-1, 1301 Catherine Street, Ann Arbor, 48109, MI, USA
| | - Javed Siddiqui
- Department of Pathology, University of Michigan, 4424B MS-1, 1301 Catherine Street, Ann Arbor, 48109, MI, USA
| | - Felix Feng
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, 4424B MS-1, 1301 Catherine Street, Ann Arbor, 48109, MI, USA.,Department of Radiation Oncology, University of San Francisco, San Francisco, CA, USA
| | - Yi Sun
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, 4424B MS-1, 1301 Catherine Street, Ann Arbor, 48109, MI, USA. .,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China. .,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, People's Republic of China.
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Kanno Y, Zhao S, Yamashita N, Yanai K, Nemoto K, Inouye Y. Androgen receptor functions as a negative transcriptional regulator of DEPTOR, mTOR inhibitor. J Toxicol Sci 2016; 40:753-8. [PMID: 26558456 DOI: 10.2131/jts.40.753] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It has been noticed that crosstalk between androgen receptor (AR) and mammalian target of rapamycin (mTOR) signaling pathways plays a crucial role in the proliferation of prostate cancer cells. To clarify this mechanism, we focused on DEPTOR, a naturally occurring inhibitor of mTOR. The treatment of a human AR-positive prostate cancer cell line, LNCaP, with the AR-agonist dihydrotestosterone (DHT) repressed DEPTOR mRNA expression in a time-dependent manner. This repression was abrogated by treatment with the AR-antagonist bicalutamide. Knockdown of DEPTOR mRNA by siRNA resulted in the increased phosphorylation of 70 kDa ribosomal protein S6 kinase 1 (S6K), a substrate of mTORC1, accompanied by the elevated expression of cyclin D1, a positive regulator of cell proliferation. Furthermore, the ChIP assay demonstrated that AR could bind to AR-responsible element-like region within the 4th intron of the DEPTOR gene. The amount of acetylated histone H3 (Lys9, Lys14) was reduced by the DHT treatment in this region. Taken together, these results propose that AR-dependent prostate cancer cell proliferation requires decreased DEPTOR transcription directly controlled by AR.
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Affiliation(s)
- Yuichiro Kanno
- Department of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Toho University
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Soliman GA, Steenson SM, Etekpo AH. Effects of Metformin and a Mammalian Target of Rapamycin (mTOR) ATP-Competitive Inhibitor on Targeted Metabolomics in Pancreatic Cancer Cell Line. ACTA ACUST UNITED AC 2016; 6. [PMID: 28217402 DOI: 10.4172/2153-0769.1000183] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pancreatic Cancer (PC) is a devastating lethal disease. Therefore, there is an urgent need to develop new intervention strategies. The mammalian Target of Rapamycin (mTOR) is a conserved kinase and master regulator of metabolism and cell growth. mTOR is dysregulated in chronic diseases including diabetes and pancreatic cancer. Recent reports indicate that 50% of Pancreatic Ductal Adenocarcinoma (PDAC) patients are diabetic at the time of diagnosis. Furthermore, the anti-diabetic drug, metformin, which indirectly inhibits mTOR, has emerged as a potential therapeutic target for PC. The objective of this study is to determine the targeted-metabolomics profile in PDAC cell line (HPAF-II) with mTOR inhibition and the interaction between mTOR ATP-competitive inhibitor (Torin 2) and metformin as potential combined therapy in PC. HPAF-II cell lines were cultured in the presence of either Torin 2, metformin, both, or control vehicle. We utilized targeted LC/MS/MS to characterize the alterations in glycolytic and tricarboxylic acid cycle metabolomics, and employed Western Blot analysis for cell signaling activation by phosphorylation. Comparisons between groups were analyzed using one-way Analysis of Variance followed by secondary post-hoc analysis. After 1 h incubation with metformin, AMP concentration was significantly increased compared to other groups (p<0.03). After 24 h, Torin-2 significantly decreased glycolysis intermediates (fructose 1,6-bisphosphate (FBP), and 2-phosphoglycerate/3-phosphoglycerate), TCA intermediate metabolites (citrate/isocitrate, and malate), as well as Nicotinamide Adenine Dinucleotide (NAD+) and Flavin Adenine Dinucleotide (FAD), and ATP levels. When HPAF-II cells were incubated with both Torin-2 and metformin, there was a significant reduction in NAD+ and FAD, suggesting decreased levels of the energy equivalents that are available to the electron transport chain. Targeted metabolomics data indicate that mTOR complexes inhibition by Torin 2 reduced glycolytic intermediates and TCA metabolites in HPAF- II and may synergize with metformin to decrease the electron acceptors NAD+ and FAD which may lead to reduced energy production.
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Affiliation(s)
- Ghada A Soliman
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
| | - Sharalyn M Steenson
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
| | - Asserewou H Etekpo
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
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Zhou X, Guo J, Ji Y, Pan G, Liu T, Zhu H, Zhao J. Reciprocal Negative Regulation between EGFR and DEPTOR Plays an Important Role in the Progression of Lung Adenocarcinoma. Mol Cancer Res 2016; 14:448-57. [PMID: 26896556 DOI: 10.1158/1541-7786.mcr-15-0480] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/10/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Xuefeng Zhou
- Department of Thoracic and Cardiovascular Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China
| | - Jialong Guo
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, P.R. China
| | - Yanmei Ji
- Department of Intensive Care Unit, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, P.R. China
| | - Gaofeng Pan
- Department of Thoracic and Cardiovascular Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China
| | - Tao Liu
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, P.R. China
| | - Hua Zhu
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio.
| | - Jinping Zhao
- Department of Thoracic and Cardiovascular Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China.
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Chen L, Liu T, Tu Y, Rong D, Cao Y. Cul1 promotes melanoma cell proliferation by promoting DEPTOR degradation and enhancing cap-dependent translation. Oncol Rep 2015; 35:1049-56. [PMID: 26717892 DOI: 10.3892/or.2015.4442] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 09/15/2015] [Indexed: 11/06/2022] Open
Abstract
Cullin1 (Cul1) serves as a rigid scaffold in the SCF (Skp1/Cullin/Rbx1/F-box protein) E3 ubiquitin ligase complex and has been found to be overexpressed in melanoma and to enhance melanoma cell proliferation by promoting G1-S phase transition. However, the underlying mechanisms involved in the regulation of melanoma cell proliferation by Cul1 remain poorly understood. In the present study, we found that Cul1 promoted mTORC1 activity and cap-dependent translation by enhancing the ubiquitination and degradation of DEPTOR. We further showed that suppression of the eIF4F complex assembly profoundly inhibited the promoting effect of Cul1 on melanoma cell proliferation, while enhancement of the eIF4F complex activity reversed the inhibitory effect of Cul1 depletion on melanoma cell proliferation, indicating that Cul1 contributes to melanoma cell proliferation by activating cap‑dependent translation. These data elucidate the role of Cul1 in cap-dependent translation and improves our understanding of the underlying mechanisms involved in the regulation of melanoma cell proliferation by Cul1.
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Affiliation(s)
- Lan Chen
- Department of Dermatology, The Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Tianyu Liu
- Department of Dermatology, The Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yunhua Tu
- Department of Dermatology, The Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Dongyun Rong
- Department of Dermatology, The Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yu Cao
- Department of Dermatology, The Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou 550004, P.R. China
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Liu NB, Zhang JH, Liu YF, Li J, Zhang ZZ, Li JW, Liu WY, Huang C, Shen T, Gu CW, Gao DY, Wu X, Wu X. High DEPTOR expression correlates with poor prognosis in patients with esophageal squamous cell carcinoma. Onco Targets Ther 2015; 8:3449-55. [PMID: 26640385 PMCID: PMC4657798 DOI: 10.2147/ott.s92862] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE The disheveled, Egl-10, and pleckstrin (DEP) domain containing mammalian target of rapamycin (mTOR)-interacting protein (DEPTOR) is a binding protein containing mTOR complex 1 (mTORC1), mTOR complex 2 (mTORC2), and an endogenous mTOR inhibitor. DEPTOR shows abnormal expressions in numerous types of solid tumors. However, how DEP-TOR is expressed in esophageal squamous cell carcinoma (ESCC) remains elusive. METHODS The expression of DEPTOR in 220 cases of ESCC and non-cancerous adjacent tissues was detected by immunohistochemistry. DEPTOR levels in ESCC and paired normal tissue were quantified using reverse transcription-polymerase chain reaction and Western blot analysis to verify the immunohistochemical results. The relationship between DEPTOR expression and the clinicopathological features of ESCC was analyzed based on the results of immunohistochemistry. Finally, we analyzed the relationship between DEPTOR expression and the prognosis of patients with ESCC. RESULTS Immunohistochemical staining showed that the expression rate of DEPTOR in ESCC tissues was significantly increased. DEPTOR mRNA and protein expression was significantly higher in ESCC tissues than in normal adjacent esophageal squamous tissues. High DEPTOR expression was significantly correlated with regional lymph node status in the TNM stage of patients with ESCC. Kaplan-Meier survival curves showed that the rate of overall survival was significantly lower in patients with high DEPTOR expression than in those with low DEPTOR expression. Additionally, high DEPTOR expression was an independent prognostic predictor for ESCC patients. CONCLUSION High DEPTOR expression is an independent prognostic biomarker indicating a worse prognosis for patients with ESCC.
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Affiliation(s)
- Nan-Bo Liu
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
| | - Jun-Hua Zhang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Yu-Fan Liu
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
| | - Jun Li
- Department of Thoracic Surgery, The Third Affiliated Hospital of Southern Medical University, Guangzhou, People's Republic of China
| | - Zhen-Zhong Zhang
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
| | - Ji-Wei Li
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
| | - Wen-Yue Liu
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
| | - Chen Huang
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China ; Department of Thoracic Surgery, Fujian Provincial Hospital, Fuzhou, People's Republic of China
| | - Tao Shen
- Department of Thoracic Surgery, Jiangmen Central Hospital, Jiangmen, People's Republic of China
| | - Cheng-Wei Gu
- Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Dong-Yun Gao
- Department of Oncology, Dongtai People's Hospital, Dongtai, People's Republic of China
| | - Xia Wu
- Department of Breast Cancer, Affiliated Hospital, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Xu Wu
- Department of Thoracic Surgery, Southern Medical University, Guangzhou, People's Republic of China
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