1
|
Zou Q, Liu M, Liu K, Zhang Y, North BJ, Wang B. E3 ubiquitin ligases in cancer stem cells: key regulators of cancer hallmarks and novel therapeutic opportunities. Cell Oncol (Dordr) 2023; 46:545-570. [PMID: 36745329 PMCID: PMC10910623 DOI: 10.1007/s13402-023-00777-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2023] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Human malignancies are composed of heterogeneous subpopulations of cancer cells with phenotypic and functional diversity. Among them, a unique subset of cancer stem cells (CSCs) has both the capacity for self-renewal and the potential to differentiate and contribute to multiple tumor properties. As such, CSCs are promising cellular targets for effective cancer therapy. At the molecular level, hyper-activation of multiple stemness regulatory signaling pathways and downstream transcription factors play critical roles in controlling CSCs establishment and maintenance. To regulate CSC properties, these stemness pathways are controlled by post-translational modifications including, but not limited to phosphorylation, acetylation, methylation, and ubiquitination. CONCLUSION In this review, we focus on E3 ubiquitin ligases and their roles and mechanisms in regulating essential hallmarks of CSCs, such as self-renewal, invasion and metastasis, metabolic reprogramming, immune evasion, and therapeutic resistance. Moreover, we discuss emerging therapeutic approaches to eliminate CSCs through targeting E3 ubiquitin ligases by chemical inhibitors and proteolysis-targeting chimera (PROTACs) which are currently under development at the discovery, preclinical, and clinical stages. Several outstanding issues such as roles for E3 ubiquitin ligases in heterogeneity and phenotypical/functional evolution of CSCs remain to be studied under pathologically and clinically relevant conditions. With the rapid application of functional genomic and proteomic approaches at single cell, spatiotemporal, and even single molecule levels, we anticipate that more specific and precise functions of E3 ubiquitin ligases will be delineated in dictating CSC properties. Rational design and proper translation of these mechanistic understandings may lead to novel therapeutic modalities for cancer procession medicine.
Collapse
Affiliation(s)
- Qiang Zou
- Department of Hepatobiliary Pancreatic Tumor Center, Chongqing University Cancer Hospital, Chongqing University Medical School, Chongqing, 400030, People's Republic of China
- Department of Gastroenterology & Chongqing Key Laboratory of Digestive Malignancies, Daping Hospital, Army Medical University (Third Military Medical University), 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, People's Republic of China
| | - Meng Liu
- Department of Gastroenterology & Chongqing Key Laboratory of Digestive Malignancies, Daping Hospital, Army Medical University (Third Military Medical University), 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, People's Republic of China
- Department of Gastroenterology, Chongqing University Cancer Hospital, Chongqing University Medical School, Chongqing, 400030, People's Republic of China
| | - Kewei Liu
- Department of Gastroenterology & Chongqing Key Laboratory of Digestive Malignancies, Daping Hospital, Army Medical University (Third Military Medical University), 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, People's Republic of China
| | - Yi Zhang
- Department of Hepatobiliary Pancreatic Tumor Center, Chongqing University Cancer Hospital, Chongqing University Medical School, Chongqing, 400030, People's Republic of China.
| | - Brian J North
- Biomedical Sciences Department, Creighton University School of Medicine, Omaha, NE, 68178, USA.
| | - Bin Wang
- Department of Gastroenterology & Chongqing Key Laboratory of Digestive Malignancies, Daping Hospital, Army Medical University (Third Military Medical University), 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, People's Republic of China.
- Institute of Pathology and Southwest Cancer Center, and Key Laboratory of Tumor Immunopathology of Ministry of Education of China, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, People's Republic of China.
- Jinfeng Laboratory, Chongqing, 401329, People's Republic of China.
| |
Collapse
|
2
|
Zhao Z, Wang H, Kang N, Wang Z, Hou X, Hu L, Qie S, Guo J, Wei S, Ruan X, Zheng X. Aurora kinase a promotes the progression of papillary thyroid carcinoma by activating the mTORC2-AKT signalling pathway. Cell Biosci 2022; 12:195. [PMID: 36471438 PMCID: PMC9721059 DOI: 10.1186/s13578-022-00934-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Treatment failure is the main cause of death from papillary thyroid carcinoma (PTC). It is urgent to look for new intervention targets and to develop new therapies for treating PTC. Aurora-A kinase (AURKA) functionally regulates cell mitosis and is closely related to the occurrence and development of a variety of tumours. However, the expression and potential functions of AURKA in PTC remain largely elusive. RESULTS Clinicopathologically, AURKA is highly expressed in PTC tissues compared to normal tissues and is correlated with lymph node metastasis, TNM stage and patient prognosis. Biologically, AURKA functions as an oncoprotein to promote the proliferation and migration of PTC cells. Mechanistically, AURKA directly binds to SIN1 and compromises CUL4B-based E3 ligase-mediated ubiquitination and subsequent degradation of SIN1, leading to hyperactivation of the mTORC2-AKT pathway in PTC cells. CONCLUSIONS We found that AURKA plays critical roles in regulating the progression of PTC by activating the mTORC2-AKT pathway, highlighting the potential of targeting AURKA to treat PTC.
Collapse
Affiliation(s)
- Zewei Zhao
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Huijuan Wang
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Ning Kang
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Zhongyu Wang
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Xiukun Hou
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Linfei Hu
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Shuo Qie
- grid.411918.40000 0004 1798 6427Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Jianping Guo
- grid.412615.50000 0004 1803 6239Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510275 Guangdong China
| | - Songfeng Wei
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Xianhui Ruan
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| | - Xiangqian Zheng
- grid.411918.40000 0004 1798 6427Department of Thyroid and Neck Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060 China
| |
Collapse
|
3
|
Zhang L, Zhao Y, Guan H, Zhang D. HnRNPU-AS1 inhibits the proliferation, migration and invasion of HCC cells and induces autophagy through miR-556-3p/ miR-580-3p/SOCS6 axis. Cancer Biomark 2022; 34:443-457. [PMID: 35275521 DOI: 10.3233/cbm-210261] [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] [Indexed: 11/15/2022]
Abstract
BACKGROUND Long non-coding RNAs have drawn increasing research interest in cancer biology. This study aims to investigate the function roles and the underlying mechanism of HnRNPU-AS1 in Hepatocellular carcinoma (HCC). METHODS qRT-PCR was performed to detect the expression levels of HnRNPU-AS1, miR-556-3p, miR-580-3p in HCC tissues and cell lines. Western blot was used to determine protein levels of LC3-II, LC3-I, Beclin-1, P62, and SOCS6. Functional assays including CCK8 assay, colony formation assay, wound healing assay, Transwell assay were performed to evaluate the role of HnRNPU-AS1 in regulating the malignant phenotype of HCC cells. Dual luciferase reporter assay and RNA pull-down experiment were used to examined the RNA-RNA interaction. RESULTS HnRNPU-AS1 expression was decreased in HCC tissues and cell lines, which was associated with poor prognosis in HCC patients. Overexpression of HnRNPU-AS1 could inhibit the proliferation, migration, invasion but promote autophagy in HCC cells. Two miRNAs (miR-556-3p and miR-580-3p) were identified as potential targets of HnRNPU-AS1 in lncBASE database, which were significantly upregulated in HCC tissues and cell lines. Cell experiments demonstrated the effects of HnRNPU-AS1 overexpression could be attenuated by miR-556-3p or miR-580-3p overexpression. We further revealed that SOX6 was the downstream target of HnRNPU-AS1/miR-556-3p or miR-580-3p axis. Xenograft mouse model validated the tumor-suppressor role of HnRNPU-AS1 overexpression in vivo. CONCLUSIONS This study demonstrated the tumor suppressor function of HnRNPU-AS1 in HCC and identified the downstream molecules underlying its tumor suppressor function. Our results suggest that HnRNPU-AS1 suppresses HCC by targeting miR-556-3p and miR-580-3p/SOXS6 axis.
Collapse
|
4
|
Zhi Y, Huang S, Lina Z. Suppressor of Cytokine Signaling 6 in cancer development and therapy: deciphering its emerging and suppressive roles. Cytokine Growth Factor Rev 2022; 64:21-32. [DOI: 10.1016/j.cytogfr.2022.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/07/2022] [Indexed: 12/16/2022]
|
5
|
Liu L, Dai X, Yin S, Liu P, Hill EG, Wei W, Gan W. DNA-PK promotes activation of the survival kinase AKT in response to DNA damage through an mTORC2-ECT2 pathway. Sci Signal 2022; 15:eabh2290. [PMID: 34982576 DOI: 10.1126/scisignal.abh2290] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Liu Liu
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Xiaoming Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Shasha Yin
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Pengda Liu
- Lineberger Comprehensive Cancer Center and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Elizabeth G Hill
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Wenjian Gan
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| |
Collapse
|
6
|
Gong L, Wang K, Wang M, Hu R, Li H, Gao D, Lin M. CUL5-ASB6 Complex Promotes p62/SQSTM1 Ubiquitination and Degradation to Regulate Cell Proliferation and Autophagy. Front Cell Dev Biol 2021; 9:684885. [PMID: 34164402 PMCID: PMC8215545 DOI: 10.3389/fcell.2021.684885] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/06/2021] [Indexed: 12/30/2022] Open
Abstract
p62/SQSTM1 (sequestosome-1) is a key protein involved in multiple cellular bioprocesses including autophagy, nutrient sensing, cell growth, cell death, and survival. Therefore, it is implicated in human diseases such as obesity and cancer. Here, we show that the CUL5–ASB6 complex is a ubiquitin E3 ligase complex mediating p62 ubiquitination and degradation. Depletion of CUL5 or ASB6 induced p62 accumulation, and overexpression of ASB6 promoted ubiquitination and degradation of p62. Functionally, ASB6 overexpression can inhibit the proliferation of MEF and hepatocellular carcinoma cells by reducing p62 protein level, and impair the occurrence of autophagy. Overall, our study identified a new molecular mechanism regulating p62 stability, which may provide additional insights for understanding the delicate control of p62 and cell proliferation–autophagy control in physiological and pathological settings.
Collapse
Affiliation(s)
- Liyan Gong
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Department of General Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China
| | - Kaihua Wang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mengcheng Wang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ronggui Hu
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Huaguang Li
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China
| | - Daming Gao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Moubin Lin
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Department of General Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China
| |
Collapse
|
7
|
Sun X, Sun Y, Li J, Zhao X, Shi X, Gong T, Pan S, Zheng Z, Zhang X. SOCS6 promotes radiosensitivity and decreases cancer cell stemness in esophageal squamous cell carcinoma by regulating c-Kit ubiquitylation. Cancer Cell Int 2021; 21:165. [PMID: 33712005 PMCID: PMC7953756 DOI: 10.1186/s12935-021-01859-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/01/2021] [Indexed: 02/07/2023] Open
Abstract
Background Radiotherapy is a major treatment for esophageal squamous cell carcinoma (ESCC). However, HPV infection related radioresistance caused poor prognosis of ESCC. The function of SOCS6, which has been shown to be a tumor suppressor in several cancers, has not been fully investigated up till now. In this manuscript, we aim to further investigate the role of SOCS6 in regulating ESCC radioresistance. Methods Fifty-seven ESCC patients were enrolled for survival analysis. SOCS6 was stably overexpressed in HPV+ ESCC and ESCC cells, and cells were treated with radiation and then subjected to colony formation assays. Expression of DNA damage repair regulating proteins were examined by Western blotting. Cell growth, cell migration and cisplatin sensitivity were then analyzed. Sphere formation assays and flow cytometry were used to investigate changes in cancer stem cell (CSC) properties. Immunofluorescent staining and confocal microscopy were used to locate SOCS6 and c-Kit. Ubiquitylation level of c-Kit were analyzed after immunoprecipitation. Then, coimmunoprecipitation (CoIP) of SOCS6 and c-Kit were performed. In vivo, xenograft animal models were treated with radiation to examine the radiosensitivity. Results SOCS6 is correlated with better prognosis in ESCC patients. Radioresistance is impaired by SOCS6 upregulation, which inhibited cell growth, migration and increased sensitivity to cisplatin. SOCS6 significantly decreased the population of CSCs expressing the surface biomarker CD271 or CD24low/CD44high and their ability of sphere formation. SOCS6 and c-Kit were collocated in the cytoplasm. Blotting of ubiquitin and CoIP experiments indicated that the mechanism was related to ubiquitylation and degradation of the receptor c-Kit. Xenograft tumor mouse model showed that SOCS6 inhibited tumor growth and promoted radiosensitivity in vivo. Conclusions Our findings suggest that SOCS6 can promote the radiosensitivity of HPV+ ESCC and ESCC cells and reduce their stemness via ubiquitylation and degradation of c-Kit. Thus, SOCS6 is a potential target for overcoming radioresistance of ESCC. Supplementary Information The online version contains supplementary material available at 10.1186/s12935-021-01859-2.
Collapse
Affiliation(s)
- Xuanzi Sun
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Yuchen Sun
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Jing Li
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Xu Zhao
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Xiaobo Shi
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Tuotuo Gong
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Shupei Pan
- Department of Radiation Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zhongqiang Zheng
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Xiaozhi Zhang
- Department of Radiation Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an, 710061, Shaanxi, China.
| |
Collapse
|
8
|
Yin S, Liu L, Gan W. The Roles of Post-Translational Modifications on mTOR Signaling. Int J Mol Sci 2021; 22:ijms22041784. [PMID: 33670113 PMCID: PMC7916890 DOI: 10.3390/ijms22041784] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth, proliferation, and metabolism by integrating various environmental inputs including growth factors, nutrients, and energy, among others. mTOR signaling has been demonstrated to control almost all fundamental cellular processes, such as nucleotide, protein and lipid synthesis, autophagy, and apoptosis. Over the past fifteen years, mapping the network of the mTOR pathway has dramatically advanced our understanding of its upstream and downstream signaling. Dysregulation of the mTOR pathway is frequently associated with a variety of human diseases, such as cancers, metabolic diseases, and cardiovascular and neurodegenerative disorders. Besides genetic alterations, aberrancies in post-translational modifications (PTMs) of the mTOR components are the major causes of the aberrant mTOR signaling in a number of pathologies. In this review, we summarize current understanding of PTMs-mediated regulation of mTOR signaling, and also update the progress on targeting the mTOR pathway and PTM-related enzymes for treatment of human diseases.
Collapse
|
9
|
Zhao Y, Xiong X, Sun Y. Cullin-RING Ligase 5: Functional characterization and its role in human cancers. Semin Cancer Biol 2020; 67:61-79. [PMID: 32334051 DOI: 10.1016/j.semcancer.2020.04.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/06/2020] [Accepted: 04/12/2020] [Indexed: 12/12/2022]
Abstract
Cullin-RING ligase 5 (CRL5) is a multi-protein complex and consists of a scaffold protien cullin 5, a RING protein RBX2 (also known as ROC2 or SAG), adaptor proteins Elongin B/C, and a substrate receptor protein SOCS. Through targeting a variety of substrates for proteasomal degradation or modulating various protein-protein interactions, CRL5 is involved in regulation of many biological processes, such as cytokine signal transduction, inflammation, viral infection, and oncogenesis. As many substrates of CRL5 are well-known oncoproteins or tumor suppressors, abnormal regulation of CRL5 is commonly found in human cancers. In this review, we first briefly introduce each of CRL5 components, and then discuss the biological processes regulated by four members of SOCS-box-containing substrate receptor family through substrate degradation. We next describe how CRL5 is hijacked by a variety of viral proteins to degrade host anti-viral proteins, which facilitates virus infection. We further discuss the regulation of CUL5 and its various roles in human cancers, acting as either a tumor suppressor or an oncoprotein in a context-dependent manner. Finally, we propose novel insights for future perspectives on the validation of cullin5 and other CRL5 components as potential targets, and possible targeting strategies to discover CRL5 inhibitors for anti-cancer and anti-virus therapies.
Collapse
Affiliation(s)
- Yongchao Zhao
- Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China.
| | - Xiufang Xiong
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China; Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Sun
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China; Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|