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Yin Q, Hu Y, Dong Z, Lu J, Wang H. Cellular, Structural Basis, and Recent Progress for Targeting Murine Double Minute X (MDMX) in Tumors. J Med Chem 2024; 67:14723-14741. [PMID: 39185935 DOI: 10.1021/acs.jmedchem.4c00913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Murine double minute X (MDMX) is an oncoprotein that mainly has a negative regulatory effect on the tumor suppressor p53 to induce tumorigenesis. As MDMX is highly expressed in various types of tumor cells, targeting and inhibiting MDMX are becoming a promising strategy for treating cancers. However, the high degree of structural homology between MDMX and its homologous protein murine double minute 2 (MDM2) is a great challenge for the development of MDMX-targeted therapies. This review introduces the structure, distribution, and regulation of the MDMX, summarizes the structural features and structure-activity relationships (SARs) of MDMX ligands, and focuses on the differences between MDMX and MDM2 in these aspects. Our purpose of this work is to propose potential strategies to achieve the specific targeting of MDMX.
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Affiliation(s)
- Qikun Yin
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Yuemiao Hu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Zhiwen Dong
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Jing Lu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Hongbo Wang
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
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Ni Y, Chen H, Cheng X, Sun B, Wu Z, Zhan Q, Zhuang Z. Hdm2 disrupts HdmX-mediated nuclear export of p53 by sequestering it in nucleus. Exp Cell Res 2024; 441:114185. [PMID: 39069150 DOI: 10.1016/j.yexcr.2024.114185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 07/24/2024] [Accepted: 07/25/2024] [Indexed: 07/30/2024]
Abstract
Dysfunction of the tumor suppressor p53 occurs in most human cancers, Hdm2 and HdmX play critical roles in p53 inactivation and degradation. Under unstressed conditions, HdmX binds to p53 like Hdm2, but HdmX cannot directly induce p53 degradation. Moreover, HdmX has been reported to stimulate Hdm2-mediated ubiquitination and degradation of p53. Here we reported that HdmX promoted the nuclear export of p53 independent of Hdm2 in living cells using FRET technology. Whereas, Hdm2 impeded HdmX-mediated nuclear export of p53 by sequestering it in nucleus. Interestingly, the C-terminal RING domain mutant Hdm2C464A formed heterooligomers with p53 in nucleus, which was inhibited by HdmX. The heterooligomers were located near PML-NBs. This study indicate that the nuclear Hdm2-HdmX interaction aborts the HdmX-mediated nuclear export of p53.
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Affiliation(s)
- Yue Ni
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China; Centre for Optical and Electromagnetic Research, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510631, China
| | - Hongce Chen
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China.
| | - Xuecheng Cheng
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China
| | - Beini Sun
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China
| | - Zhirui Wu
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China
| | - Qiuqiang Zhan
- Centre for Optical and Electromagnetic Research, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510631, China
| | - Zhengfei Zhuang
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China.
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Chen B, Zhang Y, Song G, Wei X. RNF135 Promotes Human Osteosarcoma Cell Growth and Inhibits Apoptosis by Upregulating the PI3K/AKT Pathway. Cancer Rep (Hoboken) 2024; 7:e2159. [PMID: 39118262 PMCID: PMC11310095 DOI: 10.1002/cnr2.2159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 06/24/2024] [Accepted: 07/16/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Ring finger protein 135 (RNF135) is an E3 ubiquitin ligase that has been implicated in the tumorigenesis of multiple human malignancies. However, whether RNF135 plays a role in the development of human osteosarcoma (OS) remains unknown. METHODS RNF135 expression in 20 human OS and 20 human osteochondroma specimens were evaluated by means of immunohistochemistry staining. The effects of shRNA-mediated RNF135 knockdown on human OS cell growth and apoptosis were evaluated through a panel of in vitro studies on cell proliferation, colony formation, exposure of phosphatidylserine on the cell surface, and caspase 3/7 activation. The protein levels of PI3K, AKT, and p-AKT were determined by western blot analysis. RESULTS We detected significantly higher RNF135 levels in human OS tissues than human osteochondroma tissues. In in vitro studies, shRNA-mediated RNF135 knockdown in human OS cells inhibited proliferation and induced apoptosis. In addition, RNF135 knockdown reduced PI3K and p-AKT protein levels and activated caspase 3 and 7. CONCLUSIONS These results supported that RNF135 contributes to human OS development through PI3K/AKT-dependent mechanisms. Targeting RNF135 may provide a new therapeutic approach for treating this human malignancy.
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Affiliation(s)
- Bingyao Chen
- Second Department of OrthopedicsBeijing Daxing District People's HospitalBeijingChina
- Department of OrthopedicsAerospace Central HospitalBeijingChina
- Senior Department of OrthopedicsThe Fourth Medical Center of PLA General HospitalBeijingChina
| | - Yinglong Zhang
- Senior Department of OrthopedicsThe Fourth Medical Center of PLA General HospitalBeijingChina
| | - Guangze Song
- Department of OrthopedicsAerospace Central HospitalBeijingChina
- Senior Department of OrthopedicsThe Fourth Medical Center of PLA General HospitalBeijingChina
| | - Xing Wei
- Department of OrthopedicsAerospace Central HospitalBeijingChina
- Senior Department of OrthopedicsThe Fourth Medical Center of PLA General HospitalBeijingChina
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Mao P, Feng Z, Liu Y, Zhang K, Zhao G, Lei Z, Di T, Zhang H. The Role of Ubiquitination in Osteosarcoma Development and Therapies. Biomolecules 2024; 14:791. [PMID: 39062505 PMCID: PMC11274928 DOI: 10.3390/biom14070791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/20/2024] [Accepted: 06/28/2024] [Indexed: 07/28/2024] Open
Abstract
The ubiquitin-proteasome system (UPS) maintains intracellular protein homeostasis and cellular function by regulating various biological processes. Ubiquitination, a common post-translational modification, plays a crucial role in the regulation of protein degradation, signal transduction, and other physiological and pathological processes, and is involved in the pathogenesis of various cancers, including osteosarcoma. Osteosarcoma, the most common primary malignant bone tumor, is characterized by high metastatic potential and poor prognosis. It is a refractory bone disease, and the main treatment modalities are surgery combined with chemotherapy. Increasing evidence suggests a close association between UPS abnormalities and the progression of osteosarcoma. Due to the complexity and pleiotropy of the ubiquitination system, each step in the ubiquitination process can be targeted by drugs. In recent years, research and development of inhibitors targeting the ubiquitin system have increased gradually, showing great potential for clinical application. This article reviews the role of the ubiquitination system in the development and treatment of osteosarcoma, as well as research progress, with the hope of improving the therapeutic effects and prognosis of osteosarcoma patients by targeting effective molecules in the ubiquitination system.
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Affiliation(s)
- Peng Mao
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
| | - Zuxi Feng
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Yong Liu
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
| | - Kai Zhang
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
| | - Guanghai Zhao
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
| | - Zeyuan Lei
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
| | - Tianning Di
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
| | - Haihong Zhang
- Department of Orthopedics, Lanzhou University Second Hospital, Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Orthopaedics of Gansu Province, Lanzhou University, Lanzhou 730030, China
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Ali M, Mishra D, Singh RP. Cancer Pathways Targeted by Berberine: Role of microRNAs. Curr Med Chem 2024; 31:5178-5198. [PMID: 38303534 DOI: 10.2174/0109298673275121231228124031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/26/2023] [Accepted: 12/06/2023] [Indexed: 02/03/2024]
Abstract
Cancer is a complex and heterogeneous malignant disease. Due to its multifactorial nature, including progressive changes in genetic, epigenetic, transcript, and protein levels, conventional therapeutics fail to save cancer patients. Evidence indicates that dysregulation of microRNA (miRNA) expression plays a crucial role in tumorigenesis, metastasis, cell proliferation, differentiation, metabolism, and signaling pathways. Moreover, miRNAs can be used as diagnostic and prognostic markers and therapeutic targets in cancer. Berberine, a naturally occurring plant alkaloid, has a wide spectrum of biological activities in different types of cancers. Inhibition of cell proliferation, metastasis, migration, invasion, and angiogenesis, as well as induction of cell cycle arrest and apoptosis in cancer cells, is reported by berberine. Recent studies suggested that berberine regulates many oncogenic and tumor suppressor miRNAs implicated in different phases of cancer. This review discussed how berberine inhibits cancer growth and propagation and regulates miRNAs in cancer cells. And how berberine-mediated miRNA regulation changes the landscape of transcripts and proteins that promote or suppress cancer progression. Overall, the underlying molecular pathways altered by berberine and miRNA influencing the tumor pathophysiology will enhance our understanding to combat the malignancy.
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Affiliation(s)
- Mansoor Ali
- Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Deepali Mishra
- Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rana Pratap Singh
- Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
- Special Centre for Systems Medicine, Jawaharlal Nehru University, New Delhi, India
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO, USA
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Song J, Yuan X, Piao L, Wang J, Wang P, Zhuang M, Liu J, Liu Z. Cellular functions and molecular mechanisms of ubiquitination in osteosarcoma. Front Oncol 2022; 12:1072701. [DOI: 10.3389/fonc.2022.1072701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
Although some advances have been made in the treatment of osteosarcoma in recent years, surgical resection remains the mainstream treatment. Initial and early diagnosis of osteosarcoma could be very difficult to achieve due to the insufficient sensitivity for the means of examination. The distal metastasis of osteosarcoma also predicts the poor prognosis of osteosarcoma. In order to solve this series of problems, people begin to discover a new method of diagnosing and treating osteosarcoma. Ubiquitination, as an emerging posttranslational modification, has been shown to be closely related to osteosarcoma in studies over the past decades. In general, this review describes the cellular functions and molecular mechanisms of ubiquitination during the development of osteosarcoma.
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The roles of mouse double minute 2 (MDM2) oncoprotein in ocular diseases: A review. Exp Eye Res 2022; 217:108910. [PMID: 34998788 DOI: 10.1016/j.exer.2021.108910] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/03/2021] [Accepted: 12/21/2021] [Indexed: 12/19/2022]
Abstract
Mouse double minute 2 (MDM2), an E3 ubiquitin ligase and the primary negative regulator of the tumor suppressor p53, cooperates with its structural homolog MDM4/MDMX to control intracellular p53 level. In turn, overexpression of p53 upregulates and forms an autoregulatory feedback loop with MDM2. The MDM2-p53 axis plays a pivotal role in modulating cell cycle control and apoptosis. MDM2 itself is regulated by the PI3K-AKT and RB-E2F-ARF pathways. While amplification of the MDM2 gene or overexpression of MDM2 (due to MDM2 SNP T309G, for instance) is associated with various malignancies, numerous studies have shown that MDM2/p53 alterations may also play a part in the pathogenetic process of certain ocular disorders (Fig. 1). These include cancers (retinoblastoma, uveal melanoma), fibrocellular proliferative diseases (proliferative vitreoretinopathy, pterygium), neovascular diseases, degenerative diseases (cataract, primary open-angle glaucoma, age-related macular degeneration) and infectious/inflammatory diseases (trachoma, uveitis). In addition, MDM2 is implicated in retinogenesis and regeneration after optic nerve injury. Anti-MDM2 therapy has shown potential as a novel approach to treating these diseases. Despite major safety concerns, there are high expectations for the clinical value of reformative MDM2 inhibitors. This review summarizes important findings about the role of MDM2 in ocular pathologies and provides an overview of recent advances in treating these diseases with anti-MDM2 therapies.
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Ren Z, Yang Q, Guo J, Huang H, Li B, Yang Z, Tian X. Circular RNA hsa_circ_0000073 Enhances Osteosarcoma Cells Malignant Behavior by Sponging miR-1252-5p and Modulating CCNE2 and MDM2. Front Cell Dev Biol 2021; 9:714601. [PMID: 34568326 PMCID: PMC8459753 DOI: 10.3389/fcell.2021.714601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/13/2021] [Indexed: 12/29/2022] Open
Abstract
Objective: An increasing number of studies have demonstrated that circular RNAs (circRNAs) are involved in tumor progression. However, the role of hsa_circ_0000073 in osteosarcoma (OS) is still not fully elucidated. Methods: Quantitative reverse transcription-polymerase chain reaction or Western blot was used to detect the gene expression. GeneChip analysis, bioinformatics, luciferase reporter, and RNA immunoprecipitation assays were adopted to predict and verify the relationships between genes. Counting Kit-8 Assay, clone formation assay, wound-healing assay, transwell assays, cell cycle assays, and in vivo tumorigenesis were used to evaluate cell function. Results: hsa_circ_0000073 was highly expressed in OS cell lines and could promote OS progression, including proliferation, migration, invasion, and cell cycle in vitro as well as tumorigenesis in vivo. Mechanically, hsa_circ_0000073 could readily downregulate the expression of CCNE2 and MDM2 through miR-1252-5p. Rescue experiments validated miR-1252-5p mimics, or CCNE2/MDM2 short hairpin RNA could reverse the hsa_circ_0000073 overexpressing-induced impairment of malignant tumor behavior. Conclusion: hsa_circ_0000073 functions as a tumor promoter in OS to increase malignant tumor behavior through sponging miR-1252-5p and regulating CCNE2 and MDM2 expression, which could be a novel target for OS therapy.
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Affiliation(s)
- Zhijing Ren
- Medical College of Guizhou University, Guiyang, China.,Department of Clinical Laboratory, Guizhou Provincial People's Hospital, Guiyang, China
| | - Qinqin Yang
- Medical College of Guizhou University, Guiyang, China
| | - Jiajia Guo
- Medical College of Guizhou University, Guiyang, China
| | - Haifeng Huang
- Department of Orthopedics, Guizhou Provincial People's Hospital, Guiyang, China
| | - Bo Li
- Department of Orthopedics, Guizhou Provincial People's Hospital, Guiyang, China
| | - Zhen Yang
- Medical College of Guizhou University, Guiyang, China.,Department of Orthopedics, Guizhou Provincial People's Hospital, Guiyang, China
| | - Xiaobin Tian
- Medical College of Guizhou University, Guiyang, China.,Department of Orthopedics, Affiliated Hospital of Guizhou Medical University, Guiyang, China
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Huang Z, Wang S, Wei H, Chen H, Shen R, Lin R, Wang X, Lan W, Lin R, Lin J. Inhibition of BUB1 suppresses tumorigenesis of osteosarcoma via blocking of PI3K/Akt and ERK pathways. J Cell Mol Med 2021; 25:8442-8453. [PMID: 34337852 PMCID: PMC8419163 DOI: 10.1111/jcmm.16805] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 06/24/2021] [Accepted: 07/08/2021] [Indexed: 12/31/2022] Open
Abstract
Osteosarcoma (OS) is a primary malignant bone tumour that mainly affects teenagers, with patients displaying poor prognosis. Budding uninhibited by benzimidazoles 1 (BUB1), a type of serine/threonine kinase that is linked to pro-tumorigenic phenomena, has not been well studied in OS. Hence, this study aimed to explore the role of BUB1 in OS. The expression of BUB1 in OS specimens and cell lines was assessed using immunohistochemistry and Western blot analysis. Univariate and multivariate analyses were applied to evaluate the impact of BUB1 on patient survival. Cell counting kit-8, wound-healing and Transwell assays, as well as flow cytometry, were used to investigate the influence of BUB1 inhibition on OS in vitro. Moreover, a tumour xenograft model was established to investigate the in vivo effect of BUB1 inhibition on OS tumour growth. Results showed that BUB1 was overexpressed in OS specimens and cell lines. Furthermore, BUB1 overexpression was closely associated with the poor clinical outcomes of patients with OS. Inhibition of BUB1 markedly suppressed cell proliferation and tumour growth, cell migration, invasion and induced cell apoptosis of OS by blocking the PI3K/Akt and ERK signalling pathways. Thus, our study suggested that overexpression of BUB1 protein contributed to poor survival of OS patients and that inhibition of BUB1 resulted in considerable anti-tumour activity associated with proliferation, migration, invasion and apoptosis of OS.
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Affiliation(s)
- Zhen Huang
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Orthopedics Research Institution, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Shenglin Wang
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Hongxiang Wei
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Hui Chen
- Department of Nephrology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Rongkai Shen
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Renqin Lin
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xinwen Wang
- Department of Orthopedics, The people's Hospital of Jiangmen City, Southern Medical University, Jiangmen, China
| | - Wenbin Lan
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Rongjin Lin
- Department of Nursing, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Jianhua Lin
- Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Fujian Orthopedics Research Institution, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
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Li F, Yu S, Huang X, Dong C, Ren J. Studying Homo-oligomerization and Hetero-oligomerization of MDMX and MDM2 Proteins in Single Living Cells by Using In Situ Fluorescence Correlation Spectroscopy. Biochemistry 2021; 60:1498-1505. [PMID: 33870698 DOI: 10.1021/acs.biochem.1c00153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Protein oligomerization plays a very important role in many physiological processes. p53 acts as a key tumor suppressor by regulating cell cycle arrest, DNA repair, and apoptosis, and its antitumor activity is regulated by the hetero- and homo-oligomerization of MDMX and MDM2 proteins. So far, some traditional methods have been utilized to study the oligomerization of MDMX and MDM2 in vitro, but they have not clarified some controversial issues or whether the extracellular results can represent the intracellular results. Here, we put forward an in situ method for studying protein homo- and hetero-oligomerization in single living cells by using fluorescence correlation spectroscopy. In this study, MDMX and MDM2 were labeled with fluorescent proteins using lentiviral transfection. Autocorrelation spectroscopy and cross-correlation spectroscopy methods were used to study the oligomerization of MDMX and MDM2 in situ and the effect of regulation of MDMX oligomerization on p53-MDMX interactions in single living cells. We observed the homo- and hetero-oligomerization of MDMX and MDM2 in living cells. Meanwhile, the levels of the homo-oligomers of MDMX and MDM2 were increased due to the lack of hetero-oligomerization. Finally, the binding affinity of MDMX for p53 was improved with an increase in the level of MDMX hetero-oligomerization.
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Affiliation(s)
- Fucai Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Shengrong Yu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xiangyi Huang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Chaoqing Dong
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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Zeng M, Chen Y, Jia X, Liu Y. The Anti-Apoptotic Role of EBV-LMP1 in Lymphoma Cells. Cancer Manag Res 2020; 12:8801-8811. [PMID: 33061576 PMCID: PMC7519810 DOI: 10.2147/cmar.s260583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/18/2020] [Indexed: 12/26/2022] Open
Abstract
Background Epstein-Barr virus (EBV) has been indicated in the development of some tumors, including lymphoma. However, the potential role of latent membrane protein 1 (LMP1) encoded by EBV in the tumorigenesis of lymphoma remains debated. Herein, we examined the function of LMP1 in lymphoma. Methods The expression of LMP1 was downregulated or upregulated in EBV negative cell line SNT-8 and positive cell line KHYG-1, respectively. Subsequently, the cell viability, apoptosis, as well as the expression patterns of p53, mouse double minute 2 (MDM2), B-cell CLL/lymphoma 2 (Bcl-2) and NF-κB were evaluated. Next, the binding relationship between MDM2 and p53 along with p53 ubiquitination in cells was tested by Western blot and co-immunoprecipitation. Finally, the effects of LMP1 on lymphoma cell growth through p53, Bcl-2 and NF-κB pathways were verified by functional rescue experiments. Results Overexpression of LMP1 promoted KHYG-1 cell growth and inhibited cell apoptosis. Moreover, LMP1 upregulation significantly enhanced the activation of NF-κB pathway, thus increasing MDM2 binding to p53, leading to p53 ubiquitination and degradation as well as Bcl-2 expression enhancement. Further inhibition of the NF-κB pathway or Bcl-2 expression significantly weakened the promotive role of LMP1 in the growth of KHYG-1 cells. Conclusion EBV-LMP1 promoted the p53 ubiquitination and degradation by activating NF-κB signaling pathway and the following binding of MDM2 and p53 in cells to enhance Bcl-2 expression, thus promoting the growth of lymphoma cells and inhibiting cell apoptosis.
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Affiliation(s)
- Mei Zeng
- Pathology Teaching and Research Section, Xiangyang Polytechnic, Xiangyang 441021, Hubei, People's Republic of China
| | - Yuhua Chen
- Department of Pathology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang 441021, Hubei, People's Republic of China
| | - Xintao Jia
- Department of Pathology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang 441021, Hubei, People's Republic of China
| | - Yan Liu
- Department of Pathology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang 441021, Hubei, People's Republic of China
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