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Zhuang M, Li F, Liang H, Su Y, Cheng L, Lin B, Zhou J, Deng R, Chen L, Lyu P, Lu Z. Targeting RCC1 to block the human soft-tissue sarcoma by disrupting nucleo-cytoplasmic trafficking of Skp2. Cell Death Dis 2024; 15:241. [PMID: 38561375 PMCID: PMC10985091 DOI: 10.1038/s41419-024-06629-2] [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: 10/11/2023] [Revised: 03/16/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024]
Abstract
Soft-tissue sarcomas (STS) emerges as formidable challenges in clinics due to the complex genetic heterogeneity, high rates of local recurrence and metastasis. Exploring specific targets and biomarkers would benefit the prognosis and treatment of STS. Here, we identified RCC1, a guanine-nucleotide exchange factor for Ran, as an oncogene and a potential intervention target in STS. Bioinformatics analysis indicated that RCC1 is highly expressed and correlated with poor prognosis in STS. Functional studies showed that RCC1 knockdown significantly inhibited the cell cycle transition, proliferation and migration of STS cells in vitro, and the growth of STS xenografts in mice. Mechanistically, we identified Skp2 as a downstream target of RCC1 in STS. Loss of RCC1 substantially diminished Skp2 abundance by compromising its protein stability, resulting in the upregulation of p27Kip1 and G1/S transition arrest. Specifically, RCC1 might facilitate the nucleo-cytoplasmic trafficking of Skp2 via direct interaction. As a result, the cytoplasmic retention of Skp2 would further protect it from ubiquitination and degradation. Notably, recovery of Skp2 expression largely reversed the phenotypes induced by RCC1 knockdown in STS cells. Collectively, this study unveils a novel RCC1-Skp2-p27Kip1 axis in STS oncogenesis, which holds promise for improving prognosis and treatment of this formidable malignancy.
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Affiliation(s)
- Mingzhi Zhuang
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Fengyue Li
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Hong Liang
- College of Geography and Oceanography, Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, Fujian, 350108, P. R. China
| | - Yongfu Su
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Lei Cheng
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Bingkai Lin
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Jun Zhou
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Runzhi Deng
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Linying Chen
- Department of Pathology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, 350005, P. R. China
| | - Peng Lyu
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
| | - Zhonglei Lu
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
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2
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TRIM58 Interacts with ZEB1 to Suppress NSCLC Tumor Malignancy by Promoting ZEB1 Protein Degradation via UPP. DISEASE MARKERS 2023; 2023:5899662. [PMID: 36644609 PMCID: PMC9836804 DOI: 10.1155/2023/5899662] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/05/2022] [Accepted: 12/19/2022] [Indexed: 01/07/2023]
Abstract
Background Currently, how to successfully control refractory and metastatic diseases remains a fundamental goal for clinicians to improve therapeutic effects for patients with non-small cell lung cancer (NSCLC). Several studies have discovered that TRIM58, a member of tripartite motif protein family, shows antitumor effect in multiple types of cancer. In this study, we aimed to further clarify the molecular regulatory network of TRIM58 and corresponding targets for NSCLC patients. Methods TRIM58 expression in clinical tumor tissue samples and cancer cell lines was examined. Functional experiments including cellular invasion, cell metastasis, chemoresistance assay, and ubiquitination evaluation experiments were conducted to investigate the interaction between TRIM58 and ZEB1, which is a prime element of transcription factor network that controls epithelial-to-mesenchymal transition. Results TRIM58 expression was characteristically decreased in NSCLC tumor tissues and cancer cell lines. Functional experiments demonstrated that TRIM58 suppression enhanced malignant biological behaviors including cellular survivability, migration, and invasion, as well as stem-like cellular phenotype of tumor cells. TRIM58 silencing also significantly enhanced the chemoresistance of NSCLC cells to chemoagents. TRIM58-ZEB1 interaction accelerated degradation of ZEB1 protein, thus further leading to the augment of tumor behaviors. Further detailed molecular experiments revealed that the interaction between TRIM58 and ZEB1 was mediated via ubiquitin-proteasome pathway (UPP). Conclusion TRIM58 suppressed NSCLC through interacting with ZEB1 and promoting ZEB1 protein degradation via UPP. The present research sheds light on the interaction between TRIM58 and ZEB1, and TRIM58/ZEB1 axis might be the potential therapeutic targets of NSCLC.
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Jing J, Rui L, Junyuan S, Jinfeng Y, Zhihao H, Weiguo L, Zhenyu J. Small-molecule compounds inhibiting S-phase kinase-associated protein 2: A review. Front Pharmacol 2023; 14:1122008. [PMID: 37089937 PMCID: PMC10113621 DOI: 10.3389/fphar.2023.1122008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/20/2023] [Indexed: 04/25/2023] Open
Abstract
S-phase kinase-associated protein 2 (Skp2) is a substrate-specific adaptor in Skp1-CUL1-ROC1-F-box E3 ubiquitin ligases and widely regarded as an oncogene. Therefore, Skp2 has remained as an active anticancer research topic since its discovery. Accordingly, the structure of Skp2 has been solved and numerous Skp2 inhibiting compounds have been identified. In this review, we would describe the structural features of Skp2, introduce the ubiquitination function of SCFSkp2, and summarize the diverse natural and synthetic Skp2 inhibiting compounds reported to date. The IC50 data of the Skp2 inhibitors or inhibiting compounds in various kinds of tumors at cellular levels implied that the cancer type, stage and pathological mechanisms should be taken into consideration when selecting Skp2-inhibiting compound for cancer treatment.
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Affiliation(s)
- Jia Jing
- Schools of Laboratory Medicine and Bioengineering, Hangzhou Medical College, Hangzhou, Zhejiang Province, China
| | - Li Rui
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Sun Junyuan
- Schools of Laboratory Medicine and Bioengineering, Hangzhou Medical College, Hangzhou, Zhejiang Province, China
| | - Yang Jinfeng
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang Province, China
| | - Hong Zhihao
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang Province, China
| | - Lu Weiguo
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Women′s Reproductive Health Research of Zhejiang Province, Hangzhou, Zhejiang Province, China
- *Correspondence: Lu Weiguo, ; Jia Zhenyu,
| | - Jia Zhenyu
- Institute of Occupation Diseases, Hangzhou Medical College, Hangzhou, Zhejiang Province, China
- *Correspondence: Lu Weiguo, ; Jia Zhenyu,
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APC-Cdh1 Inhibits the Proliferation and Activation of Oligodendrocyte Precursor Cells after Mechanical Stretch Injury. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9524561. [PMID: 31139661 PMCID: PMC6500630 DOI: 10.1155/2019/9524561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/25/2019] [Indexed: 12/21/2022]
Abstract
The incidence of spinal cord injury (SCI) continues to increase; however, the involved mechanisms remain unclear. Anaphase promoting complex (APC) and its regulatory subunit Cdh1 play important roles in the growth, development, and repair of the central nervous system (CNS). Cdh1 is involved in the pathophysiological processes of neuronal apoptosis and astrocyte-reactive proliferation after ischemic brain injury, whereas the role played by APC-Cdh1 in the proliferation and activation of oligodendrocyte precursor cells (OPCs) after SCI remains unresolved. Using primary cultures of spinal oligodendrocyte precursor cells, we successfully established an in vitro mechanical stretch injury model to simulate SCI. Cell viability and proliferation were determined by MTT assay and flow cytometric analysis of the cell cycle. Real-time fluorescent quantitative PCR and Western blot analysis determined the mRNA and protein expression levels of Cdh1 and its downstream substrates Skp2 and Id2. Mechanical stretch injury decreased the proliferative activity of OPCs and enhanced cellular Cdh1 expression. Dampened expression of Cdh1 in primary OPCs significantly promoted proliferation and activation of OPCs after SCI. In addition, the expression of the downstream substrates of Cdh1, Skp2, and Id2 was decreased following mechanical injury, whereas adenovirus-mediated Cdh1 RNA interference increased postinjury expression of Skp2 and Id2. These findings suggest that APC-Cdh1 might be involved in regulating the proliferation and activation of OPCs after mechanical SCI. Moreover, degraded ubiquitination of the downstream substrates Skp2 and Id2 might play an important role, at least in part, in the beneficial effects of OPCs activity following SCI.
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Davey NE, Morgan DO. Building a Regulatory Network with Short Linear Sequence Motifs: Lessons from the Degrons of the Anaphase-Promoting Complex. Mol Cell 2017; 64:12-23. [PMID: 27716480 DOI: 10.1016/j.molcel.2016.09.006] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The anaphase-promoting complex or cyclosome (APC/C) is a ubiquitin ligase that polyubiquitinates specific substrates at precise times in the cell cycle, thereby triggering the events of late mitosis in a strict order. The robust substrate specificity of the APC/C prevents the potentially deleterious degradation of non-APC/C substrates and also averts the cell-cycle errors and genomic instability that could result from mistimed degradation of APC/C targets. The APC/C recognizes short linear sequence motifs, or degrons, on its substrates. The specific and timely modification and degradation of APC/C substrates is likely to be modulated by variations in degron sequence and context. We discuss the extensive affinity, specificity, and selectivity determinants encoded in APC/C degrons, and we describe some of the extrinsic mechanisms that control APC/C-substrate recognition. As an archetype for protein motif-driven regulation of cell function, the APC/C-substrate interaction provides insights into the general properties of post-translational regulatory systems.
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Affiliation(s)
- Norman E Davey
- Conway Institute of Biomolecular and Biomedical Sciences, University College Dublin, Dublin 4, Ireland.
| | - David O Morgan
- Departments of Physiology and Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA.
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Pavlides SC, Lecanda J, Daubriac J, Pandya UM, Gama P, Blank S, Mittal K, Shukla P, Gold LI. TGF-β activates APC through Cdh1 binding for Cks1 and Skp2 proteasomal destruction stabilizing p27kip1 for normal endometrial growth. Cell Cycle 2017; 15:931-47. [PMID: 26963853 DOI: 10.1080/15384101.2016.1150393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We previously reported that aberrant TGF-β/Smad2/3 signaling in endometrial cancer (ECA) leads to continuous ubiquitylation of p27(kip1)(p27) by the E3 ligase SCF-Skp2/Cks1 causing its degradation, as a putative mechanism involved in the pathogenesis of this cancer. In contrast, normal intact TGF-β signaling prevents degradation of nuclear p27 by SCF-Skp2/Cks1 thereby accumulating p27 to block Cdk2 for growth arrest. Here we show that in ECA cell lines and normal primary endometrial epithelial cells, TGF-β increases Cdh1 and its binding to APC/C to form the E3 ligase complex that ubiquitylates Cks1 and Skp2 prompting their proteasomal degradation and thus, leaving p27 intact. Knocking-down Cdh1 in ECA cell lines increased Skp2/Cks1 E3 ligase activity, completely diminished nuclear and cytoplasmic p27, and obviated TGF-β-mediated inhibition of proliferation. Protein synthesis was not required for TGF-β-induced increase in nuclear p27 and decrease in Cks1 and Skp2. Moreover, half-lives of Cks1 and Skp2 were extended in the Cdh1-depleted cells. These results suggest that the levels of p27, Skp2 and Cks1 are strongly or solely regulated by proteasomal degradation. Finally, an inverse relationship of low p27 and high Cks1 in the nucleus was shown in patients in normal proliferative endometrium and grade I-III ECAs whereas differentiated secretory endometrium showed the reverse. These studies implicate Cdh1 as the master regulator of TGF-β-induced preservation of p27 tumor suppressor activity. Thus, Cdh1 is a potential therapeutic target for ECA and other human cancers showing an inverse relationship between Cks1/Skp2 and p27 and/or dysregulated TGF-β signaling.
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Affiliation(s)
- Savvas C Pavlides
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,b Divisions of Translational Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Jon Lecanda
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,b Divisions of Translational Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Julien Daubriac
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,b Divisions of Translational Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Unnati M Pandya
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,b Divisions of Translational Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Patricia Gama
- c Department of Cell and Developmental Biology , Institute of Biomedical Sciences, University of Sao Paolo , Brazil
| | - Stephanie Blank
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,d Gynecologic Oncology, New York University School of Medicine Langone Medical Center , New York , NY , USA.,e Perlmutter Cancer Center at NYU, New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Khushbakhat Mittal
- d Gynecologic Oncology, New York University School of Medicine Langone Medical Center , New York , NY , USA.,e Perlmutter Cancer Center at NYU, New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Pratibha Shukla
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,d Gynecologic Oncology, New York University School of Medicine Langone Medical Center , New York , NY , USA.,e Perlmutter Cancer Center at NYU, New York University School of Medicine Langone Medical Center , New York , NY , USA
| | - Leslie I Gold
- a Department of Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,b Divisions of Translational Medicine , New York University School of Medicine Langone Medical Center , New York , NY , USA.,e Perlmutter Cancer Center at NYU, New York University School of Medicine Langone Medical Center , New York , NY , USA.,f Department of Pathology , New York University School of Medicine Langone Medical Center , New York , NY , USA
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7
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Liu W, Chen H, Wong N, Haynes W, Baker CM, Wang X. Pseudohypoxia induced by miR-126 deactivation promotes migration and therapeutic resistance in renal cell carcinoma. Cancer Lett 2017; 394:65-75. [PMID: 28257806 DOI: 10.1016/j.canlet.2017.02.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 12/19/2022]
Abstract
Pseudohypoxia plays a central role in the progression and therapeutic resistance of clear cell renal cell carcinoma (ccRCC); however, the underlying mechanisms are poorly understood. MicroRNA miR-126 has decreased expression in metastatic or relapsed ccRCC as compared to primary tumors, but the mechanisms by which miR-126 is implicated in RCC remain unknown. Through RNA-seq profiling to evaluate the impact of overexpression or CRISPR knockout of miR-126, we have identified SERPINE1 as a miR-126-5p target regulating cell motility, and SLC7A5 as a miR-126-3p target regulating the mTOR/HIF pathway. Specifically, miR-126 inhibits HIFα protein expression independent of von Hippel-Lindau tumor suppressor (VHL). On the other hand, deactivation of miR-126 induces a pseudohypoxia state due to increased HIFα expression, which further enhances therapeutic resistance and cell motility mediated by SLC7A5 and SERPINE1, respectively. Finally, the clinical relevance of miR-126 modulated gene regulation in ccRCC has been confirmed with profiling data from The Cancer Genome Atlas.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- CRISPR-Cas Systems
- Carcinoma, Renal Cell/metabolism
- Carcinoma, Renal Cell/pathology
- Carcinoma, Renal Cell/therapy
- Cell Movement/drug effects
- Cell Movement/radiation effects
- Cisplatin/pharmacology
- Computational Biology
- Databases, Genetic
- Dose-Response Relationship, Drug
- Dose-Response Relationship, Radiation
- Drug Resistance, Neoplasm
- Gene Expression Regulation, Neoplastic
- Gene Knockdown Techniques
- HEK293 Cells
- HeLa Cells
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Kidney Neoplasms/genetics
- Kidney Neoplasms/metabolism
- Kidney Neoplasms/pathology
- Kidney Neoplasms/therapy
- Large Neutral Amino Acid-Transporter 1/genetics
- Large Neutral Amino Acid-Transporter 1/metabolism
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Neoplasm Invasiveness
- Plasminogen Activator Inhibitor 1/genetics
- Plasminogen Activator Inhibitor 1/metabolism
- RNA Interference
- Radiation Tolerance
- Signal Transduction/drug effects
- Signal Transduction/radiation effects
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Transfection
- Tumor Hypoxia
- Von Hippel-Lindau Tumor Suppressor Protein/genetics
- Von Hippel-Lindau Tumor Suppressor Protein/metabolism
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Affiliation(s)
- Weijun Liu
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hanxiang Chen
- Institute of Pathogenic Biology, Shandong University School of Medicine, Jinan, Shandong, China; Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Nathan Wong
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Wesley Haynes
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Callie M Baker
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Xiaowei Wang
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA.
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8
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Qi M, Liu D, Zhang S, Hu P, Sang T. Inhibition of S-phase kinase-associated protein 2-mediated p27 degradation suppresses tumorigenesis and the progression of hepatocellular carcinoma. Mol Med Rep 2015; 11:3934-40. [PMID: 25572801 DOI: 10.3892/mmr.2015.3156] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 10/01/2014] [Indexed: 11/06/2022] Open
Abstract
In order to determine the protein expression of S‑phase kinase‑associated protein 2 (Skp2) and p27kip1, and to evaluate their possible prognostic values in malignant liver cancer, tissue samples from 50 patients and 40 controls were assessed and analyzed by immunohistochemistry and western blot analysis. Positive expression of Skp2 was observed in 35 (70.0%) of the hepatocellular carcinoma samples; however, the positive expression of p27kip1 was observed in 6 (15.0%) of the hepatocellular carcinoma samples. The expression of Skp2 was significantly negatively correlated with the expression of p27 (P<0.01). The results from Annexin V‑propidium iodide staining and MTT assays indicated that interference of Skp2 significantly induced apoptosis and inhibited the proliferation of SSMC‑7721 cells. In addition, the levels of endogenous p27 increased in the HepG2 and SSMC‑7721 cells following transfection with siRNA specific to Skp2, suggesting that the Skp2‑mediated degradation of p27kip1 was important in the proliferation of tumor cells. The present study, therefore, provided a molecular reference for the treatment of liver cancer.
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Affiliation(s)
- Ming Qi
- Department of Digestive System, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
| | - Dongmei Liu
- Department of Transfusion Center, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
| | - Shuhong Zhang
- Department of Digestive System, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
| | - Peixin Hu
- Department of Digestive System, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
| | - Tan Sang
- Department of Hematology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
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9
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Arnold L, Höckner S, Seufert W. Insights into the cellular mechanism of the yeast ubiquitin ligase APC/C-Cdh1 from the analysis of in vivo degrons. Mol Biol Cell 2014; 26:843-58. [PMID: 25540434 PMCID: PMC4342022 DOI: 10.1091/mbc.e14-09-1342] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) controls a variety of cellular processes through its ability to target numerous protein substrates for timely degradation. Substrate selection by this ubiquitin ligase depends on related activator proteins, Cdc20 and Cdh1, which bind and activate the APC/C at distinct cell cycle stages. Biochemical and structural studies revealed that Cdc20 and Cdh1 carry conserved receptor domains to recognize specific sequence motifs in substrates, such as D and KEN boxes. The mechanisms for ordered degradation of APC/C substrates, however, remain incompletely understood. Here we describe minimal degradation sequences (degrons) sufficient for rapid APC/C-Cdh1-specific in vivo degradation. The polo kinase Cdc5-derived degron contained an essential KEN motif, whereas a single RxxL-type D box was the relevant signal in the Cdc20-derived degradation domain, indicating that either motif may support specific recognition by Cdh1. In both degrons, the APC/C recognition motif was flanked by a nuclear localization sequence. Forced localization of the degron constructs revealed that proteolysis mediated by APC/C-Cdh1 is restricted to the nucleus and maximally active in the nucleoplasm. Levels of Iqg1, a cytoplasmic Cdh1 substrate, decreased detectably later than the nucleus-localized Cdh1 substrate Ase1, indicating that confinement to the nucleus may allow for temporal control of APC/C-Cdh1-mediated proteolysis.
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Affiliation(s)
- Lea Arnold
- Department of Genetics, University of Regensburg, D-93040 Regensburg, Germany
| | - Sebastian Höckner
- Department of Genetics, University of Regensburg, D-93040 Regensburg, Germany
| | - Wolfgang Seufert
- Department of Genetics, University of Regensburg, D-93040 Regensburg, Germany
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10
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Xu F, Zhu X, Han T, You X, Liu F, Ye L, Zhang X, Wang X, Yao Y. The oncoprotein hepatitis B X-interacting protein promotes the migration of ovarian cancer cells through the upregulation of S-phase kinase-associated protein 2 by Sp1. Int J Oncol 2014; 45:255-63. [PMID: 24788380 DOI: 10.3892/ijo.2014.2411] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 11/18/2013] [Indexed: 11/05/2022] Open
Abstract
Hepatitis B X-interacting protein (HBXIP) is a novel oncoprotein. We have previously reported that HBXIP promotes the proliferation and migration of breast cancer cells. S-phase kinase-associated protein 2 (Skp2) is another oncoprotein which is important for migration. In this study, we investigated whether Skp2 is involved in the migration enhanced by HBXIP in ovarian cancer. The expression of HBXIP and Skp2 in ovarian cancer tissues was examined by immunohistochemistry using tissue microarrays. The role of HBXIP and Skp2 in the migration of ovarian cancer cells was investigated by wound-healing assay and Transwell migration assay. The effect of HBXIP on Skp2 was assessed by reverse transcription polymerase chain reaction (RT-PCR), western blot analysis, luciferase reporter gene assays and chromatin immunoprecipitation in ovarian cancer cells (SKOV3 and CAOV3). We found that both HBXIP and Skp2 were highly expressed in ovarian cancer tissues. We observed that the overexpression of HBXIP enhanced the migration of ovarian cancer cells, while Skp2 siRNAs decreased the cell migration enhanced by HBXIP. The HBXIP siRNAs inhibited ovarian cancer cell migration and Skp2 rescued the migration inhibition induced by HBXIP siRNA. HBXIP could upregulate Skp2 at the levels of mRNA and protein in ovarian cancer cells. Moreover, HBXIP increased the activity of Skp2 promoter via binding to the transcription factor Sp1. HBXIP is highly expressed in ovarian cancer tissues. HBXIP enhances the migration of ovarian cancer cells. HBXIP was able to stimulate the activity of Skp2 promoter via transcription factor Sp1 thus promoting the migration of ovarian cancer cells.
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Affiliation(s)
- Fuqiang Xu
- Department of Gynecology and Obstetrics, General Hospital Chinese PLA, Beijing 100853, P.R. China
| | - Xiaoming Zhu
- Department of Gynecology and Obstetrics, General Hospital Chinese PLA, Beijing 100853, P.R. China
| | - Tao Han
- Department of Orthopedics, Hainan Branch of PLA General Hospital, Sanya, Hainan 572013, P.R. China
| | - Xiaona You
- Department of Cancer Research, Key Laboratory of Molecular Microbiology and Technology of Ministry of Education, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, P.R. China
| | - Fabao Liu
- Department of Biochemistry, State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, P.R. China
| | - Lihong Ye
- Department of Biochemistry, State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, P.R. China
| | - Xiaodong Zhang
- Department of Cancer Research, Key Laboratory of Molecular Microbiology and Technology of Ministry of Education, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, P.R. China
| | - Xiaohong Wang
- Department of Obstetrics and Gynecology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Yuanqing Yao
- Department of Gynecology and Obstetrics, General Hospital Chinese PLA, Beijing 100853, P.R. China
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11
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Al-Salihi MA, Herhaus L, Sapkota GP. Regulation of the transforming growth factor β pathway by reversible ubiquitylation. Open Biol 2013; 2:120082. [PMID: 22724073 PMCID: PMC3376735 DOI: 10.1098/rsob.120082] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 04/25/2012] [Indexed: 12/20/2022] Open
Abstract
The transforming growth factor β (TGFβ) signalling pathway plays a central role during embryonic development and in adult tissue homeostasis. It regulates gene transcription through a signalling cascade from cell surface receptors to intracellular SMAD transcription factors and their nuclear cofactors. The extent, duration and potency of signalling in response to TGFβ cytokines are intricately regulated by complex biochemical processes. The corruption of these regulatory processes results in aberrant TGFβ signalling and leads to numerous human diseases, including cancer. Reversible ubiquitylation of pathway components is a key regulatory process that plays a critical role in ensuring a balanced response to TGFβ signals. Many studies have investigated the mechanisms by which various E3 ubiquitin ligases regulate the turnover and activity of TGFβ pathway components by ubiquitylation. Moreover, recent studies have shed new light into their regulation by deubiquitylating enzymes. In this report, we provide an overview of current understanding of the regulation of TGFβ signalling by E3 ubiquitin ligases and deubiquitylases.
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Affiliation(s)
- Mazin A Al-Salihi
- Medical Research Council-Protein Phosphorylation Unit, Sir James Black Centre, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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12
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Suzuki S, Ohashi N, Kitagawa M. Roles of the Skp2/p27 axis in the progression of chronic nephropathy. Cell Mol Life Sci 2012; 70:3277-87. [PMID: 23255047 PMCID: PMC3753466 DOI: 10.1007/s00018-012-1232-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 11/14/2012] [Accepted: 12/03/2012] [Indexed: 12/20/2022]
Abstract
S-phase kinase-associated protein 2 (Skp2) is an F-box protein component of the Skp/Cullin/F-box-type E3 ubiquitin ligase that targets several cell cycle regulatory proteins for degradation through the ubiquitin-dependent pathway. Skp2-mediated degradation of p27, a cyclin-dependent kinase inhibitor, is involved in cell cycle regulation. Tubular epithelial cell proliferation is a characteristic feature of renal damage that is apparent in the early stages of nephropathy. The p27 level is associated with the progression of renal injury, and increased Skp2 expression in progressive nephropathy is implicated in decreases of p27 expression. In Skp2−/− mice, renal damage caused by unilateral ureteral obstruction (UUO) was ameliorated by p27 accumulation, mainly in tubular epithelial cells. However, the amelioration of UUO-induced renal injury in Skp2−/− mice was prevented by p27 deficiency in Skp2−/−/p27−/− mice. These results suggest that the Skp2-mediated reduction in p27 is a pathogenic activity that occurs during the progression of nephropathy. Here, we discuss the roles of the Skp2/p27 axis and/or related signaling pathways/components in the progression of chronic nephropathy.
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Affiliation(s)
- Sayuri Suzuki
- Department of Molecular Biology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan
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13
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Chen L, Tweddle DA. p53, SKP2, and DKK3 as MYCN Target Genes and Their Potential Therapeutic Significance. Front Oncol 2012; 2:173. [PMID: 23226679 PMCID: PMC3508619 DOI: 10.3389/fonc.2012.00173] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 11/01/2012] [Indexed: 12/15/2022] Open
Abstract
Neuroblastoma is the most common extra-cranial solid tumor of childhood. Despite significant advances, it currently still remains one of the most difficult childhood cancers to cure, with less than 40% of patients with high-risk disease being long-term survivors. MYCN is a proto-oncogene implicated to be directly involved in neuroblastoma development. Amplification of MYCN is associated with rapid tumor progression and poor prognosis. Novel therapeutic strategies which can improve the survival rates whilst reducing the toxicity in these patients are therefore required. Here we discuss genes regulated by MYCN in neuroblastoma, with particular reference to p53, SKP2, and DKK3 and strategies that may be employed to target them.
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Affiliation(s)
- Lindi Chen
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Newcastle University Newcastle, UK
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14
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Yan L, Yun N, Xiu-Min D, Xu-Qi X. Oncogenic role of Skp2 and p27Kip1 in intraductal proliferative lesions of the breast. ACTA ACUST UNITED AC 2012; 27:161-6. [PMID: 23062638 DOI: 10.1016/s1001-9294(14)60049-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate whether the connection of p27(Kip1) to S-phase kinase-associated protein 2 (Skp2) plays an oncogenic role in intraductal proliferative lesions of the breast. METHODS Here we investigated the mechanism involved in association of Skp2’s degradation of p27(Kip1) with the breast carcinogenesis by immunohistochemical method through detection of Skp2 and p27(Kip1) protein levels in 120 paraffin-embedded tissues of intraductal proliferative lesions including usual ductal hyperplasia (UDH, n=30), atypical ductal hyperplasia (n=30), flat epithelial atypia (FEA, n=30), and ductal carcinoma in situ (DCIS, n=30). Moreover, the expression status of Skp2 and p27(Kip1) in 30 cases of the normal breast paraffin-embedded tissues were explored. RESULTS The DCIS group was with the highest Skp2 level and the lowest p27(Kip1) level, and the UDH group was with the lowest Skp2 level and the highest p27(Kip1) level.Both Skp2 and p27(Kip1) levels in the DCIS group were significantly different from those in the UDH group (all P<0.01).The levels of Skp2 and p27(Kip1) in the FEA group were significantly different from both the DCIS and UDH groups (all P<0.05).p27(Kip1) was negatively correlated with Skp2 in both the UDH group (r=-0.629, P=0.026) and DCIS group (r=-0.893, P=0.000). CONCLUSION Overexpression of Skp2 might be the mechanism underlying p27(Kip1) over degradation.
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Affiliation(s)
- Lv Yan
- Department of Acupuncture and Moxibustion, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.
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15
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Voutsadakis IA. The ubiquitin-proteasome system and signal transduction pathways regulating Epithelial Mesenchymal transition of cancer. J Biomed Sci 2012; 19:67. [PMID: 22827778 PMCID: PMC3418218 DOI: 10.1186/1423-0127-19-67] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 07/09/2012] [Indexed: 02/08/2023] Open
Abstract
Epithelial to Mesenchymal transition (EMT) in cancer, a process permitting cancer cells to become mobile and metastatic, has a signaling hardwire forged from development. Multiple signaling pathways that regulate carcinogenesis enabling characteristics in neoplastic cells such as proliferation, resistance to apoptosis and angiogenesis are also the main players in EMT. These pathways, as almost all cellular processes, are in their turn regulated by ubiquitination and the Ubiquitin-Proteasome System (UPS). Ubiquitination is the covalent link of target proteins with the small protein ubiquitin and serves as a signal to target protein degradation by the proteasome or to other outcomes such as endocytosis, degradation by the lysosome or specification of cellular localization. This paper reviews signal transduction pathways regulating EMT and being regulated by ubiquitination.
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Affiliation(s)
- Ioannis A Voutsadakis
- Centre Pluridisciplinaire d'Oncologie, BH06, Centre Hospitalier Universitaire Vaudois, Bugnon 46, Lausanne, 1011, Switzerland.
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16
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Bargagna-Mohan P, Paranthan RR, Hamza A, Zhan CG, Lee DM, Kim KB, Lau DL, Srinivasan C, Nakayama K, Nakayama KI, Herrmann H, Mohan R. Corneal antifibrotic switch identified in genetic and pharmacological deficiency of vimentin. J Biol Chem 2011; 287:989-1006. [PMID: 22117063 DOI: 10.1074/jbc.m111.297150] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The type III intermediate filaments (IFs) are essential cytoskeletal elements of mechanosignal transduction and serve critical roles in tissue repair. Mice genetically deficient for the IF protein vimentin (Vim(-/-)) have impaired wound healing from deficits in myofibroblast development. We report a surprising finding made in Vim(-/-) mice that corneas are protected from fibrosis and instead promote regenerative healing after traumatic alkali injury. This reparative phenotype in Vim(-/-) corneas is strikingly recapitulated by the pharmacological agent withaferin A (WFA), a small molecule that binds to vimentin and down-regulates its injury-induced expression. Attenuation of corneal fibrosis by WFA is mediated by down-regulation of ubiquitin-conjugating E3 ligase Skp2 and up-regulation of cyclin-dependent kinase inhibitors p27(Kip1) and p21(Cip1). In cell culture models, WFA exerts G(2)/M cell cycle arrest in a p27(Kip1)- and Skp2-dependent manner. Finally, by developing a highly sensitive imaging method to measure corneal opacity, we identify a novel role for desmin overexpression in corneal haze. We demonstrate that desmin down-regulation by WFA via targeting the conserved WFA-ligand binding site shared among type III IFs promotes further improvement of corneal transparency without affecting cyclin-dependent kinase inhibitor levels in Vim(-/-) mice. This dissociates a direct role for desmin in corneal cell proliferation. Taken together, our findings illuminate a previously unappreciated pathogenic role for type III IF overexpression in corneal fibrotic conditions and also validate WFA as a powerful drug lead toward anti-fibrosis therapeutic development.
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Affiliation(s)
- Paola Bargagna-Mohan
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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The emerging role of APC/CCdh1 in development. Semin Cell Dev Biol 2011; 22:579-85. [PMID: 21497201 DOI: 10.1016/j.semcdb.2011.03.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/24/2011] [Accepted: 03/30/2011] [Indexed: 01/10/2023]
Abstract
The function of APC/C (anaphase-promoting complex/cyclosome) was initially implicated with the onset of anaphase during mitosis, where its association with Cdc20 targets securin for destruction, thereby allowing the separation of two duplicated daughter genomes. When combined with Cdh1, APC regulates G1/S transition and DNA replication during cell cycle. Beyond cell cycle control, results from recent biochemical and mouse genetic studies have attracted our attention to the unexpected impact of APC/C(Cdh1) in cellular differentiation, genomic integrity and pathogenesis of various diseases. This review will aim to summarize current understanding of APC/C(Cdh1) in regulating crucial events during development.
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