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Tian Z, Zhu L, Xie Y, Hu H, Ren Q, Liu J, Wang Q. The mechanism of high mobility group box-1 protein and its bidirectional regulation in tumors. BIOMOLECULES & BIOMEDICINE 2024; 24:477-485. [PMID: 37897664 PMCID: PMC11088895 DOI: 10.17305/bb.2023.9760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/01/2023] [Accepted: 10/26/2023] [Indexed: 10/30/2023]
Abstract
High-mobility group box-1 protein (HMGB1) is a nonhistone chromatin-related protein widely found in eukaryotic cells. It is involved in the transcription, replication, and repair of DNA to maintain nuclear homeostasis. It participates in cell growth, differentiation, and signal transduction. Recent studies showed that HMGB1 has a bidirectional regulatory effect on tumors by regulating TLR4/MYD88/NF-κB and RAGE/AMPK/mTOR signaling pathways. On the one hand, it is highly expressed in a variety of tumors, promoting tumor proliferation and invasion, while on the other hand, it induces autophagy and apoptosis of tumor cells and stimulates tumor-infiltrating lymphocytes to produce an anti-tumor immune response. At present, HMGB1 could be used as a target to regulate the drug resistance and prognostication in cancer. Clinical applications of HMGB1 in cancer need further in-depth studies.
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Affiliation(s)
- Zhongjia Tian
- The Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, China
| | - Lin Zhu
- The Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, China
| | - Yutong Xie
- The Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, China
| | - Huan Hu
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, China
| | - Qunli Ren
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, China
| | - Jianguo Liu
- The Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, China
| | - Qian Wang
- The Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, China
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2
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Ma G, Sun Y, Cai F, Zhang M, Liang H, Deng J, Zhang R, Zhang L. DEPTOR as a novel prognostic marker inhibits the proliferation via deactivating mTOR signaling pathway in gastric cancer cells. Exp Cell Res 2023; 427:113598. [PMID: 37054772 DOI: 10.1016/j.yexcr.2023.113598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 02/15/2023] [Accepted: 04/09/2023] [Indexed: 04/15/2023]
Abstract
Aberrantly activated mTOR signaling pathway is commonly found in malignancies including gastric cancer (GC). DEPTOR, as a naturally occurred inhibitor of mTOR, functions in the pro- or anti-tumor manner depending on distinct tumor contexts. However, the roles of DEPTOR in GC remain largely unknown. In this study, DEPTOR expression was identified to be significantly decreased in GC tissues compared with matched normal gastric tissues, and reduced DEPTOR level was indicative of poor prognosis in patients. Restored DEPTOR expression inhibited the propagation in AGS and NCI-N87 cells, whose DEPTOR levels are low, via deactivating mTOR signaling pathway. Likewise, cabergoline (CAB) attenuated the proliferation in AGS and NCI-N87 cells via partially rescuing DEPTOR protein level. Targeted metabolomics analysis showed that several key metabolites, such as l-serine, significantly changed in AGS cells with DEPTOR restoration. These results revealed the anti-proliferation function of DEPTOR in GC cells, suggesting that restored DEPTOR expression using CAB may be a potential therapeutic approach for patients with GC.
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Affiliation(s)
- Gang Ma
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Yi Sun
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Fenglin Cai
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Mengmeng Zhang
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Han Liang
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Jingyu Deng
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Rupeng Zhang
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Li Zhang
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.
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3
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Gandhi M, Bakhai V, Trivedi J, Mishra A, De Andrés F, LLerena A, Sharma R, Nair S. Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction. Transl Oncol 2022; 25:101532. [PMID: 36103755 PMCID: PMC9478452 DOI: 10.1016/j.tranon.2022.101532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/15/2022] Open
Abstract
This review discusses the emerging single cell technologies and applications in Multiple myeloma (MM), population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction. The role(s) of epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of MM are also discussed. It is understood that ethnic component acts as a driver of variable response to chemotherapy in different sub-populations globally. This review augments our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, myeloma microenvironment at the molecular and cellular level, and developing precision medicine strategies to combat this malignancy. The emerging single cell technologies hold great promise for enhancing our understanding of MM tumor heterogeneity and clonal diversity.
Multiple myeloma (MM) is an aggressive cancer characterised by malignancy of the plasma cells and a rising global incidence. The gold standard for optimum response is aggressive chemotherapy followed by autologous stem cell transplantation (ASCT). However, majority of the patients are above 60 years and this presents the clinician with complications such as ineligibility for ASCT, frailty, drug-induced toxicity and differential/partial response to treatment. The latter is partly driven by heterogenous genotypes of the disease in different subpopulations. In this review, we discuss emerging single cell technologies and applications in MM, population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction, as well as the role(s) played by epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of the disease. Taken together, our discussions further our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, augment our understanding of the myeloma microenvironment at the molecular and cellular level and provide a basis for developing precision medicine strategies to combat this malignancy.
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Affiliation(s)
- Manav Gandhi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 6900 Lake Nona Blvd., Orlando, FL 32827, USA
| | - Viral Bakhai
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS University, V. L. Mehta Road, Vile Parle (West), Mumbai 400056, India
| | - Jash Trivedi
- University of Mumbai, Santa Cruz, Mumbai 400055, India
| | - Adarsh Mishra
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS University, V. L. Mehta Road, Vile Parle (West), Mumbai 400056, India
| | - Fernando De Andrés
- INUBE Extremadura Biosanitary Research Institute, Badajoz, Spain; Faculty of Medicine, University of Extremadura, Badajoz, Spain; CICAB Clinical Research Center, Pharmacogenetics and Personalized Medicine Unit, Badajoz University Hospital, Extremadura Health Service, Badajoz, Spain
| | - Adrián LLerena
- INUBE Extremadura Biosanitary Research Institute, Badajoz, Spain; Faculty of Medicine, University of Extremadura, Badajoz, Spain; CICAB Clinical Research Center, Pharmacogenetics and Personalized Medicine Unit, Badajoz University Hospital, Extremadura Health Service, Badajoz, Spain
| | - Rohit Sharma
- Department of Rasa Shastra and Bhaishajya Kalpana, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India.
| | - Sujit Nair
- University of Mumbai, Santa Cruz, Mumbai 400055, India.
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4
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Vega M, Chen Y, Shi Y, Gera J, Lichtenstein A. Turnover of the mTOR inhibitor, DEPTOR, and downstream AKT phosphorylation in multiple myeloma cells, is dependent on ERK1-mediated phosphorylation. J Biol Chem 2022; 298:101750. [PMID: 35216969 PMCID: PMC8933699 DOI: 10.1016/j.jbc.2022.101750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/27/2022] Open
Abstract
DEPTOR is a 48 kDa protein upregulated in multiple myeloma (MM) cells. DEPTOR inhibits mTOR and, by repressing a negative feedback loop, promotes AKT activation. We previously identified a compound that binds to DEPTOR in MM cells and induces its proteasomal degradation. To identify the mechanism of degradation, here, we screened for drug-induced posttranslational modifications and identified reduced phosphorylation of DEPTOR on serine 235 (S235). We show that an S235 phosphomimetic DEPTOR mutant was resistant to degradation, confirming the importance of this posttranslational modification. In addition, a DEPTOR mutant with a serine-to-alanine substitution at S235 could only be expressed upon concurrent proteasome inhibition. Thus, S235 phosphorylation regulates DEPTOR stability. Screening the DEPTOR interactome identified that the association of USP-7 deubiquitinase with DEPTOR was dependent upon S235 phosphorylation. Inhibition of USP-7 activity resulted in DEPTOR polyubiquitination and degradation. A scansite search suggested that ERK1 may be responsible for S235 phosphorylation, which was confirmed through the use of inhibitors, ERK1 knockdown, and an in vitro kinase assay. Inhibition of ERK1 also downregulated AKT phosphorylation. To test if DEPTOR phosphorylation mediated this crosstalk, MM cells were transfected with WT or phosphomimetic DEPTOR and exposed to ERK inhibitors. Although WT DEPTOR had no effect on the inhibition of AKT phosphorylation, the phosphomimetic DEPTOR prevented inhibition. These results indicate that ERK1 maintains AKT activity in MM cells via phosphorylation of DEPTOR. We propose that DEPTOR-dependent crosstalk provides MM cells with a viability-promoting signal (through AKT) when proliferation is stimulated (through ERK).
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Affiliation(s)
- Mario Vega
- Hematology-Oncology, Greater Los Angeles VA-UCLA Healthcare Center, UCLA and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California
| | - Yu Chen
- Molecular Instrumentation Center, UCLA and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California
| | - Yijiang Shi
- Hematology-Oncology, Greater Los Angeles VA-UCLA Healthcare Center, UCLA and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California
| | - Joseph Gera
- Hematology-Oncology, Greater Los Angeles VA-UCLA Healthcare Center, UCLA and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California
| | - Alan Lichtenstein
- Hematology-Oncology, Greater Los Angeles VA-UCLA Healthcare Center, UCLA and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California.
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5
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Hou Y, Kuang W, Min W, Liu Z, Zhang F, Yuan K, Wang X, Sun C, Cheng H, Wang L, Xiao Y, Pu S, Xin GZ, Yang P. Design, Synthesis, and Biological Evaluation of Icaritin Derivatives as Novel Putative DEPTOR Inhibitors for Multiple Myeloma Treatment. J Med Chem 2021; 64:14942-14954. [PMID: 34644502 DOI: 10.1021/acs.jmedchem.1c00087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Icaritin is an active ingredient in Epimedium, which has a variety of pharmacological activities. However, the low activity of Icaritin and the unclear target greatly limit its application. Therefore, based on the structure of Icaritin, we adopted the strategy of replacing toxic groups and introducing active groups to design and synthesize a series of new analogues. The top compound C3 exhibited better antimultiple myeloma activity with an IC50 of 1.09 μM for RPMI 8226 cells, induced RPMI 8226 apoptosis, and blocked the cell cycle in the S phase. Importantly, transcriptome analysis, cellular thermal shift assay, and microscale thermophoresis assay confirmed that DEPTOR was the target of C3. Moreover, we explored its binding mode with C3. Especially, C3 displayed satisfactory inhibition of tumor growth in RPMI 8226 xenografts without obvious side effects. In summary, C3 was discovered as a novel putative inhibitor of DEPTOR for the treatment of multiple myeloma.
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Affiliation(s)
- Yi Hou
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,State Key Laboratory of Natural Medicines, Department of Chinese Medicines Analysis, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China.,Department of Chinese Medicine Resources, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Wenbin Kuang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Wenjian Min
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Ziwen Liu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
| | - Fang Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Kai Yuan
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xiao Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Chengliang Sun
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Hao Cheng
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Liping Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Yibei Xiao
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
| | - Sheban Pu
- Department of Chinese Medicine Resources, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Gui-Zhong Xin
- State Key Laboratory of Natural Medicines, Department of Chinese Medicines Analysis, China Pharmaceutical University, Nanjing 210009, China.,Department of Chinese Medicine Resources, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Peng Yang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
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6
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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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7
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Bi Y, Chen X, Wei B, Wang L, Gong L, Li H, Xiong X, Zhao Y. DEPTOR stabilizes ErbB2 to promote the proliferation and survival of ErbB2-positive breast cancer cells. Am J Cancer Res 2021; 11:6355-6369. [PMID: 33995662 PMCID: PMC8120212 DOI: 10.7150/thno.51286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 03/30/2021] [Indexed: 12/13/2022] Open
Abstract
Rationale: Dysregulation of the PI3K/AKT/mTOR pathway occurs frequently in cancers, providing an attractive therapeutic target for anticancer treatments. DEPTOR plays essential roles in regulation of cell proliferation and survival by directly modulating mTOR activity. However, whether DEPTOR regulates the growth of ErbB2-positive breast cancer cells remains unknown. Methods: DEPTOR expression was determined by TCGA data analysis and immunohistochemistry of human breast tissue microarrays. The membrane localization of DEPTOR was demonstrated by immunofluorescence and subcellular fractionation. The interaction of DEPTOR with ErbB2 was determined by immunoprecipitation. Furthermore, the biological significance of this interaction was assessed by ATPlite cell growth, clonogenic survival, and flow cytometry-based apoptosis assays. Results: DEPTOR promoted the proliferation and survival of ErbB2-positive breast cancer cells by directly interacting with and stabilizing ErbB2. Specifically, DEPTOR translocates to cell membrane and interacts with ErbB2 to disrupt ErbB2 polyubiquitination and degradation promoted by β-TrCP, an E3 ubiquitin ligase. DEPTOR knockdown destabilizes ErbB2 by shortening its protein half-life to inactivate ErbB2-PI3K-AKT-mTOR signaling, leading to the suppression of cell proliferation and survival by inducing apoptosis. Ectopic expression of a constitutively active ErbB2 mutant completely rescued the reduction in cell proliferation and survival by DEPTOR knockdown. Importantly, DEPTOR expression is increased in human breast cancer tissues and its overexpression correlates with poor patient survival. Moreover, DEPTOR is located on the cell membrane in ErbB2-positive breast cancer tissues, but not in tumor-adjacent normal tissues, indicating that DEPTOR may contribute to the oncogenic characteristics of ErbB2. Conclusions: Our study reveals a novel mechanism by which DEPTOR promotes breast cancer cell proliferation and survival by stabilizing ErbB2.
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8
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Morales-Martinez M, Lichtenstein A, Vega MI. Function of Deptor and its roles in hematological malignancies. Aging (Albany NY) 2021; 13:1528-1564. [PMID: 33412518 PMCID: PMC7834987 DOI: 10.18632/aging.202462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/10/2020] [Indexed: 12/12/2022]
Abstract
Deptor is a protein that interacts with mTOR and that belongs to the mTORC1 and mTORC2 complexes. Deptor is capable of inhibiting the kinase activity of mTOR. It is well known that the mTOR pathway is involved in various signaling pathways that are involved with various biological processes such as cell growth, apoptosis, autophagy, and the ER stress response. Therefore, Deptor, being a natural inhibitor of mTOR, has become very important in its study. Because of this, it is important to research its role regarding the development and progression of human malignancies, especially in hematologic malignancies. Due to its variation in expression in cancer, it has been suggested that Deptor can act as an oncogene or tumor suppressor depending on the cellular or tissue context. This review discusses recent advances in its transcriptional and post-transcriptional regulation of Deptor. As well as the advances regarding the activities of Deptor in hematological malignancies, its possible role as a biomarker, and its possible clinical relevance in these malignancies.
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Affiliation(s)
- Mario Morales-Martinez
- Molecular Signal Pathway in Cancer Laboratory, UIMEO, Oncology Hospital, Siglo XXI National Medical Center, IMSS, México City, México
| | - Alan Lichtenstein
- Department of Medicine, Hematology-Oncology Division, Greater Los Angeles VA Healthcare Center, UCLA Medical Center, Jonsson Comprehensive Cancer Center, Los Angeles, CA 90024, USA
| | - Mario I Vega
- Molecular Signal Pathway in Cancer Laboratory, UIMEO, Oncology Hospital, Siglo XXI National Medical Center, IMSS, México City, México.,Department of Medicine, Hematology-Oncology Division, Greater Los Angeles VA Healthcare Center, UCLA Medical Center, Jonsson Comprehensive Cancer Center, Los Angeles, CA 90024, USA
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9
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Vega MI, Shi Y, Frost P, Huerta-Yepez S, Antonio-Andres G, Hernandez-Pando R, Lee J, Jung ME, Gera JF, Lichtenstein A. A Novel Therapeutic Induces DEPTOR Degradation in Multiple Myeloma Cells with Resulting Tumor Cytotoxicity. Mol Cancer Ther 2019; 18:1822-1831. [PMID: 31395691 DOI: 10.1158/1535-7163.mct-19-0115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/19/2019] [Accepted: 07/30/2019] [Indexed: 11/16/2022]
Abstract
Prior work indicates DEPTOR expression in multiple myeloma cells could be a therapeutic target. DEPTOR binds to mTOR via its PDZ domain and inhibits mTOR kinase activity. We previously identified a drug, which prevented mTOR-DEPTOR binding (NSC126405) and induced multiple myeloma cytotoxicity. We now report on a related therapeutic, drug 3g, which induces proteasomal degradation of DEPTOR. DEPTOR degradation followed drug 3g binding to its PDZ domain and was not due to caspase activation or enhanced mTOR phosphorylation of DEPTOR. Drug 3g enhanced mTOR activity, and engaged the IRS-1/PI3K/AKT feedback loop with reduced phosphorylation of AKT on T308. Activation of TORC1, in part, mediated multiple myeloma cytotoxicity. Drug 3g was more effective than NSC126405 in preventing binding of recombinant DEPTOR to mTOR, preventing binding of DEPTOR to mTOR inside multiple myeloma cells, in activating mTOR and inducing apoptosis in multiple myeloma cells. In vivo, drug 3g injected daily abrogated DEPTOR expression in xenograft tumors and induced an antitumor effect although modest weight loss was seen. Every-other-day treatment, however, was equally effective without weight loss. Drug 3g also reduced DEPTOR expression in normal tissues. Although no potential toxicity was identified in hematopoietic or hepatic function, moderate cardiac enlargement and glomerular mesangial hypertrophy was seen. DEPTOR protected multiple myeloma cells against bortezomib suggesting anti-DEPTOR drugs could synergize with proteasome inhibitors (PI). Indeed, combinations of drug NSC126405 + bortezomib were synergistic. In contrast, drug 3g was not and was even antagonistic. This antagonism was probably due to prevention of proteasomal DEPTOR degradation.
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Affiliation(s)
- Mario I Vega
- Hematology-Oncology, VA West LA-UCLA Medical Center, Los Angeles, California
| | - Yijiang Shi
- Hematology-Oncology, VA West LA-UCLA Medical Center, Los Angeles, California
| | - Patrick Frost
- Hematology-Oncology, VA West LA-UCLA Medical Center, Los Angeles, California
| | - Sara Huerta-Yepez
- Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico.,Pathology & Laboratory Medicine, UCLA Medical School, Los Angeles, California
| | - Gabriela Antonio-Andres
- Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico.,Pathology & Laboratory Medicine, UCLA Medical School, Los Angeles, California
| | | | | | - Michael E Jung
- Department of Chemistry & Biochemistry, University of California, Los Angeles, California.,Jonsson Cancer Center, University of California, Los Angeles, California
| | - Joseph F Gera
- Hematology-Oncology, VA West LA-UCLA Medical Center, Los Angeles, California.,Jonsson Cancer Center, University of California, Los Angeles, California
| | - Alan Lichtenstein
- Hematology-Oncology, VA West LA-UCLA Medical Center, Los Angeles, California. .,Jonsson Cancer Center, University of California, Los Angeles, California
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10
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Chen J, Zhu H, Liu Q, Ning D, Zhang Z, Zhang L, Mo J, Du P, Liu X, Song S, Fan Y, Liang H, Liu J, Zhang B, Chen X. DEPTOR induces a partial epithelial-to-mesenchymal transition and metastasis via autocrine TGFβ1 signaling and is associated with poor prognosis in hepatocellular carcinoma. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:273. [PMID: 31228948 PMCID: PMC6588925 DOI: 10.1186/s13046-019-1220-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/08/2019] [Indexed: 12/19/2022]
Abstract
Background DEPTOR is an endogenous inhibitor of mTORC1 and mTORC2 that plays a vital role in the progression of human malignances. However, the biological function of DEPTOR in HCC metastasis and the underlying molecular mechanisms are still unclear. Methods Western blot analysis and immunohistochemistry(IHC) were employed to examine DEPTOR expression in HCC cell lines and tissues. A series of in vivo and in vitro assays were performed to determine the function of DEPTOR and the possible mechanisms underlying its role in HCC metastasis. Results We found that DEPTOR was frequently overexpressed in HCC tissues, and its high expression was associated with high serum AFP levels, increased tumor size, vascular invasion and more advanced TMN and BCLC stage, as well as an overall poor prognosis. Functional experiments demonstrated that DEPTOR silencing inhibited the proliferation and mobility of HCC cells in vitro and suppressed tumor growth and metastasis of HCC cells in vivo. Accordingly, DEPTOR overexpression promoted the invasion and metastasis of HCC cells in vitro and in vivo, but had no effect on cell proliferation in vitro. Overexpression of DEPTOR induced EMT by snail induction. Conversely, knockdown of snail expression impaired the DEPTOR-induced migration, invasion and EMT of HCC cells. Furthermore, we found that the increase of snail expression by DEPTOR overexpression was due to an activation of TGF-β1-smad3/smad4 signaling possibly through feedback inhibition of mTOR. Conclusion DEPTOR promotes the EMT and metastasis of HCC cells by activating the TGF-β1-smad3/smad4-snail pathway via mTOR inhibition. Therefore, targeting DEPTOR may be an ideal treatment strategy for inhibiting the growth and metastasis of HCC. Electronic supplementary material The online version of this article (10.1186/s13046-019-1220-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jin Chen
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Haidan Zhu
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, People's Republic of China
| | - Qiumeng Liu
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Deng Ning
- Department of Biliary and Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Zhaoqi Zhang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Long Zhang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Jie Mo
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Pengcheng Du
- Department of Biliary and Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Xu Liu
- Hepato-pancreato-biliary Surgery Department, Peking University Shenzhen Hospital, Shenzhen, Guangdong, People's Republic of China
| | - Shasha Song
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Yawei Fan
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Huifang Liang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China
| | - Jikui Liu
- Hepato-pancreato-biliary Surgery Department, Peking University Shenzhen Hospital, Shenzhen, Guangdong, People's Republic of China.
| | - Bixiang Zhang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China.
| | - Xiaoping Chen
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology; Clinical Medicine Research Center for Hepatic Surgery of Hubei Province; Key Laboratory of Organ Transplantation, Ministry of Education and Ministry of Public Health, Wuhan, Hubei, 430030, People's Republic of China.
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11
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Ma Y, Jin Z, Yu K, Liu Q. NVP-BEZ235-induced autophagy as a potential therapeutic approach for multiple myeloma. Am J Transl Res 2019; 11:87-105. [PMID: 30787971 PMCID: PMC6357299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The PI3K/Akt/mTOR pathway is constitutively activated in human multiple myeloma (MM) cell lines and in freshly isolated plasmocytes from patients with MM. The mTOR signaling pathway has been designated an attractive anti-tumor target in multiple myeloma. NVP-BEZ235, a novel, dual class I PI3K/mTOR inhibitor, is an imidazoquinoline derivative. NVP-BEZ235 binds to the ATP-binding clefts of PI3K and mTOR kinase, thereby inhibiting their activities. Increasing evidence shows that NVP-BEZ235 is able to effectively and specifically reverse the hyperactivation of the PI3K/mTOR pathway, resulting not only in potent antiproliferative and antitumor activities in a broad range of cancer cell lines and experimental tumors but also in autophagy. METHOD The antitumor, apoptosis, and autophagy effects of NVP-BEZ235 were measured in three MM cell lines, two leukemia cell lines, and primary CD138+ myeloma cells from MM patients and nude mouse MM models. In addition, the relationships between autophagy, cell death and apoptosis induced by NVP-BEZ235 were analyzed in MM cells. Furthermore, we explored the mechanism of autophagy induced by NVP-BEZ235 in MM cells. RESULTS NVP-BEZ235 inhibited proliferation and induced apoptosis and autophagy in MM cells and in primary MM cells from patients and nude mouse MM models. Autophagy played an important role in the cell death and apoptosis of MM cell lines induced by NVP-BEZ235, and the mechanism involved the mTOR2-Akt-FOXO3a-BNIP3 pathway. CONCLUSIONS In this study, NVP-BEZ235 showed the strongest antitumor and autophagy induction activity. Moreover, the mechanism involved the mTOR2-Akt-FOXO3a-BNIP3 pathway. Our study lays a theoretical foundation for NVP-BEZ235 clinical application.
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Affiliation(s)
- Yongyong Ma
- Department of Hematology, The First Affiliated Hospital of Wenzhou Medical University2 Nanbai Xiang, Wenzhou 325000, China
- Department of Hematology, Nanfang Hospital, Southern Medical UniversityGuangzhou 510010, China
| | - Zhouxiang Jin
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University109#, Xueyuan Western Road, Wenzhou 325027, China
| | - Kang Yu
- Department of Hematology, The First Affiliated Hospital of Wenzhou Medical University2 Nanbai Xiang, Wenzhou 325000, China
| | - Qifa Liu
- Department of Hematology, Nanfang Hospital, Southern Medical UniversityGuangzhou 510010, China
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12
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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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Guo X, He D, Zhang E, Chen J, Chen Q, Li Y, Yang L, Yang Y, Zhao Y, Wang G, He J, Cai Z. HMGB1 knockdown increases MM cell vulnerability by regulating autophagy and DNA damage repair. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2018; 37:205. [PMID: 30157958 PMCID: PMC6114506 DOI: 10.1186/s13046-018-0883-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 08/16/2018] [Indexed: 02/06/2023]
Abstract
Background With the development of novel therapeutic agents, the survival of multiple myeloma (MM) patients has much improved. However, the disease is incurable due to drug resistance. Previous studies have found that high-mobility group box 1 (HMGB1) is involved in inflammation, angiogenesis, DNA damage repair, and cancer invasion, progression, metastasis and drug resistance and that high HMGB1 expression is associated with poor MM prognosis, yet the role and mechanism of HMGB1 in MM remains unclear. Methods Through gene expression and Oncomine database analyses, we found that HMGB1 is associated with a poor prognosis in MM patients. RNA interference together with gene array analysis, cell proliferation and apoptosis assays, autophagy detection assays, western blotting, and in vivo xenograft models were employed to evaluate the effect of HMGB1 and the mechanism involved in MM drug resistance. Results MM cell lines and primary MM samples were found to express high levels of HMGB1, which was negatively associated with the 3-year survival of MM patients. HMGB1 knockdown in MM cells enhanced the inhibitory effect of chemotherapy with dexamethasone (Dex) via apoptosis induction. Furthermore, downregulation of HMGB1 activated the mTOR pathway, inhibited autophagy and increased DNA damage induced by Dex by modulating expression of related genes. In vivo, xenograft models showed that after Dex treatment, the tumor burden of HMGB1-knockdown mice was decreased compared with that of control mice. Conclusions Our research shows that HMGB1 participates in autophagy and DNA damage repair and that downregulation of HMGB1 enhances the sensitivity of MM cells to Dex, suggesting that HMGB1 may serve as a target for MM treatment.
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Affiliation(s)
- Xing Guo
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Donghua He
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Enfan Zhang
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Jing Chen
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Qingxiao Chen
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Yi Li
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Li Yang
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Yang Yang
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Yi Zhao
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Gang Wang
- Quzhou People's Hospital, Quzhou, 324000, Zhejiang, China
| | - Jingsong He
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Zhen Cai
- Bone Marrow Transplantation Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, Zhejiang, China.
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14
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Targeting signaling pathways in multiple myeloma: Pathogenesis and implication for treatments. Cancer Lett 2018; 414:214-221. [DOI: 10.1016/j.canlet.2017.11.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 12/15/2022]
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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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Lee J, Shi Y, Vega M, Yang Y, Gera J, Jung ME, Lichtenstein A. Structure-activity relationship study of small molecule inhibitors of the DEPTOR-mTOR interaction. Bioorg Med Chem Lett 2017; 27:4714-4724. [PMID: 28916338 DOI: 10.1016/j.bmcl.2017.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 09/01/2017] [Accepted: 09/01/2017] [Indexed: 11/30/2022]
Abstract
DEPTOR is a 48kDa protein that binds to mTOR and inhibits this kinase within mTORC1 and mTORC2 complexes. Over-expression of DEPTOR specifically occurs in the multiple myeloma (MM) tumor model and DEPTOR knockdown is cytotoxic to MM cells, suggesting it is a potential therapeutic target. Since mTORC1 paralysis protects MM cells against DEPTOR knockdown, it indicates that the protein-protein interaction between DEPTOR and mTOR is key to MM viability vs death. In a previous study, we used a yeast two-hybrid screen of a small inhibitor library to identify a compound that inhibited DEPTOR/mTOR binding in yeast. This therapeutic (compound B) also prevented DEPTOR/mTOR binding in MM cells and was selectively cytotoxic to MM cells. We now present a structure-activity relationship (SAR) study around this compound as a follow-up report of this previous work. This study has led to the discovery of five new leads - namely compounds 3g, 3k, 4d, 4e and 4g - all of which have anti-myeloma cytotoxic properties superior to compound B. Due to their targeting of DEPTOR, these compounds activate mTORC1 and selectively induce MM cell apoptosis and cell cycle arrest.
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Affiliation(s)
- Jihye Lee
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Yijiang Shi
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Mario Vega
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Yonghui Yang
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Joseph Gera
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Research and Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA 91343, USA
| | - Michael E Jung
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Alan Lichtenstein
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Research and Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA 91343, USA.
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WITHDRAWN: Structure-activity relationship study of small molecule inhibitors of the DEPTOR-mTOR interaction. Bioorg Med Chem 2017. [DOI: 10.1016/j.bmc.2017.08.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Benavides-Serrato A, Lee J, Holmes B, Landon KA, Bashir T, Jung ME, Lichtenstein A, Gera J. Specific blockade of Rictor-mTOR association inhibits mTORC2 activity and is cytotoxic in glioblastoma. PLoS One 2017; 12:e0176599. [PMID: 28453552 PMCID: PMC5409528 DOI: 10.1371/journal.pone.0176599] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/13/2017] [Indexed: 12/19/2022] Open
Abstract
A small molecule which specifically blocks the interaction of Rictor and mTOR was identified utilizing a high-throughput yeast two-hybrid screen and evaluated as a potential inhibitor of mTORC2 activity in glioblastoma multiforme (GBM). In vitro, CID613034 inhibited mTORC2 kinase activity at submicromolar concentrations and in cellular assays specifically inhibited phosphorylation of mTORC2 substrates, including AKT (Ser-473), NDRG1 (Thr-346) and PKCα (Ser-657), while having no appreciable effects on the phosphorylation status of the mTORC1 substrate S6K (Thr-389) or mTORC1-dependent negative feedback loops. CID613034 demonstrated significant inhibitory effects on cell growth, motility and invasiveness in GBM cell lines and sensitivity correlated with relative Rictor or SIN1 expression. Structure-activity relationship analyses afforded an inhibitor, JR-AB2-011, with improved anti-GBM properties and blocked mTORC2 signaling and Rictor association with mTOR at lower effective concentrations. In GBM xenograft studies, JR-AB2-011 demonstrated significant anti-tumor properties. These data support mTORC2 as a viable therapeutic target in GBM and suggest that targeting protein-protein interactions critical for mTORC2 function is an effective strategy to achieve therapeutic responses.
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Affiliation(s)
- Angelica Benavides-Serrato
- Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California, United States of America
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
| | - Jihye Lee
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, United States of America
| | - Brent Holmes
- Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California, United States of America
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
| | - Kenna A. Landon
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
| | - Tariq Bashir
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
| | - Michael E. Jung
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, United States of America
- Jonnson Comprehensive Cancer Center, University of California-Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California, United States of America
| | - Alan Lichtenstein
- Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California, United States of America
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
- Jonnson Comprehensive Cancer Center, University of California-Los Angeles, Los Angeles, California, United States of America
| | - Joseph Gera
- Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California, United States of America
- Department of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States of America
- Jonnson Comprehensive Cancer Center, University of California-Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California, United States of America
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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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