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Tao Y, Dai L, Liang W, Li X, Lyu Y, Li J, Li Z, Shi Z, Liang X, Zhou S, Fu X, Hu W, Wang X. Advancements and perspectives of RBX2 as a molecular hallmark in cancer. Gene 2024; 892:147864. [PMID: 37820940 DOI: 10.1016/j.gene.2023.147864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 09/18/2023] [Accepted: 09/29/2023] [Indexed: 10/13/2023]
Abstract
Cancer is a challenging issue for human health. One of the key methods to address this issue is by comprehending the molecular causes of tumors and creating medications that target those causes. RBX2 (RING box protein 2), also known as ROC2 (Regulator of Cullins 2), RNF7 (RING Finger Protein 7), or SAG (Sensitive to Apoptosis Gene) is a key component of the Cullin-RING-type E3 ubiquitin ligases (CRLs) and overexpressed in various human cancers. RBX2 is a potential drug target, the expression of which correlates with tumor staging, grading, and prognosis analysis. Through a synergistically biological interaction with Kras mutation in preclinical models, RBX2 accelerated the progression of skin cancer, pancreatic cancer, and lung cancer. In accordance, the aberrant expression of RBX2 will lead to dysregulation of many signaling pathways, which is crucial for tumor initiation and growth. However, the impact of RBX2 on tumors also intriguingly demonstrates a spatial reliance manner. In this review, we summarized the current understanding of RBX2 in multiple cancer types and suggested a significant potential of RBX2 as a therapeutic target.
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Affiliation(s)
- Yiran Tao
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Lirui Dai
- Department of Neurosurgery, Pituitary Adenoma Multidisciplinary Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Wulong Liang
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Xiang Li
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Yuan Lyu
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China; Medical Research Center, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, PR China; Institute of Neuroscience, Zhengzhou University, Zhengzhou, Henan 450052, PR China
| | - Junqi Li
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China; Medical Research Center, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, PR China; Institute of Neuroscience, Zhengzhou University, Zhengzhou, Henan 450052, PR China
| | - Zian Li
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Zimin Shi
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Xianyin Liang
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Shaolong Zhou
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Xudong Fu
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Weihua Hu
- Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China
| | - Xinjun Wang
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China; Henan International Joint Laboratory of Glioma Metabolism and Microenvironment Research, Zhengzhou, Henan, PR China.
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Itokawa M, Miyashita M, Arai M, Dan T, Takahashi K, Tokunaga T, Ishimoto K, Toriumi K, Ichikawa T, Horiuchi Y, Kobori A, Usami S, Yoshikawa T, Amano N, Washizuka S, Okazaki Y, Miyata T. Pyridoxamine: A novel treatment for schizophrenia with enhanced carbonyl stress. Psychiatry Clin Neurosci 2018; 72:35-44. [PMID: 29064136 DOI: 10.1111/pcn.12613] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 09/07/2017] [Accepted: 10/18/2017] [Indexed: 12/16/2022]
Abstract
AIM The aim of this clinical trial was to obtain proof of concept for high-dose pyridoxamine as a novel treatment for schizophrenia with enhanced carbonyl stress. METHODS Ten Japanese schizophrenia patients with high plasma pentosidine, which is a representative biomarker of enhanced carbonyl stress, were recruited in a 24-week, open trial in which high-dose pyridoxamine (ranging from 1200 to 2400 mg/day) was administered using a conventional antipsychotic regimen. Main outcomes were the total change in Positive and Negative Syndrome Scale score and the Brief Psychiatric Rating Scale score from baseline to end of treatment at week 24 (or at withdrawal). RESULTS Decreased plasma pentosidine levels were observed in eight patients. Two patients showed marked improvement in their psychological symptoms. A patient who harbors a frameshift mutation in the Glyoxalase 1 gene also showed considerable reduction in psychosis accompanied with a moderate decrease in plasma pentosidine levels. A reduction of greater than 20% in the assessment scale of drug-induced Parkinsonism occurred in four patients. Although there was no severe suicide-related ideation or behavior, Wernicke's encephalopathy-like adverse drug reactions occurred in two patients and were completely suppressed by thiamine supplementation. CONCLUSION High-dose pyridoxamine add-on treatment was, in part, effective for a subpopulation of schizophrenia patients with enhanced carbonyl stress. Further randomized, placebo-controlled trials with careful monitoring will be required to validate the efficacy of high-dose pyridoxamine for these patients.
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Affiliation(s)
- Masanari Itokawa
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Department of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan.,Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Japan
| | - Mitsuhiro Miyashita
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Department of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan.,Department of Psychiatry, Shinshu University School of Medicine, Matsumoto, Japan
| | - Makoto Arai
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takashi Dan
- Division of Molecular Medicine and Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | | - Taro Tokunaga
- Department of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan
| | - Kayo Ishimoto
- Department of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan
| | - Kazuya Toriumi
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Tomoe Ichikawa
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yasue Horiuchi
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Akiko Kobori
- Project for Schizophrenia Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Satoshi Usami
- Graduate School of Education, University of Tokyo, Tokyo, Japan
| | - Takeo Yoshikawa
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Japan
| | - Naoji Amano
- Department of Psychiatry, Shinshu University School of Medicine, Matsumoto, Japan
| | - Shinsuke Washizuka
- Department of Psychiatry, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yuji Okazaki
- Department of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan
| | - Toshio Miyata
- Division of Molecular Medicine and Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan
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Yoo DY, Yoo KY, Park JH, Kwon HJ, Jung HY, Kim JW, Choi GM, Moon SM, Kim DW, Yoon YS, Won MH, Hwang IK. Time- and cell-type specific changes in iron, ferritin, and transferrin in the gerbil hippocampal CA1 region after transient forebrain ischemia. Neural Regen Res 2016; 11:924-30. [PMID: 27482220 PMCID: PMC4962589 DOI: 10.4103/1673-5374.184490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In the present study, we used immunohistochemistry and western blot analysis to examine changes in the levels and cellular localization of iron, heavy chain ferritin (ferritin-H), and transferrin in the gerbil hippocampal CA1 region from 30 minutes to 7 days following transient forebrain ischemia. Relative to sham controls, iron reactivity increased significantly in the stratum pyramidale and stratum oriens at 12 hours following ischemic insult, transiently decreased at 1-2 days and then increased once again within the CA1 region at 4-7 days after ischemia. One day after ischemia, ferritin-H immunoreactivity increased significantly in the stratum pyramidale and decreased at 2 days. At 4-7 days after ischemia, ferritin-H immunoreactivity in the glial components in the CA1 region was significantly increased. Transferrin immunoreactivity was increased significantly in the stratum pyramidale at 12 hours, peaked at 1 day, and then decreased significantly at 2 days after ischemia. Seven days after ischemia, Transferrin immunoreactivity in the glial cells of the stratum oriens and radiatum was significantly increased. Western blot analyses supported these results, demonstrating that compared to sham controls, ferritin H and transferrin protein levels in hippocampal homogenates significantly increased at 1 day after ischemia, peaked at 4 days and then decreased. These results suggest that iron overload-induced oxidative stress is most prominent at 12 hours after ischemia in the stratum pyramidale, suggesting that this time window may be the optimal period for therapeutic intervention to protect neurons from ischemia-induced death.
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Affiliation(s)
- Dae Young Yoo
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Ki-Yeon Yoo
- Department of Oral Anatomy, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, South Korea
| | - Joon Ha Park
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Hyun Jung Kwon
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, South Korea
| | - Hyo Young Jung
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Jong Whi Kim
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Goang-Min Choi
- Department of Thoracic and Cardiovascular Surgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Seung Myung Moon
- Department of Neurosurgery, Dongtan Sacred Heart Hospital, College of Medicine, Hallym University, Hwaseong, South Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, South Korea
| | - Yeo Sung Yoon
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
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Yan BC, Park JH, Chen BH, Cho JH, Kim IH, Ahn JH, Lee JC, Hwang IK, Cho JH, Lee YL, Kang IJ, Won MH. Long-term administration of scopolamine interferes with nerve cell proliferation, differentiation and migration in adult mouse hippocampal dentate gyrus, but it does not induce cell death. Neural Regen Res 2014; 9:1731-9. [PMID: 25422633 PMCID: PMC4238160 DOI: 10.4103/1673-5374.143415] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2014] [Indexed: 11/04/2022] Open
Abstract
Long-term administration of scopolamine, a muscarinic receptor antagonist, can inhibit the survival of newly generated cells, but its effect on the proliferation, differentiation and migration of nerve cells in the adult mouse hippocampal dentate gyrus remain poorly understood. In this study, we used immunohistochemistry and western blot methods to weekly detect the biological behaviors of nerve cells in the hippocampal dentate gyrus of adult mice that received intraperitoneal administration of scopolamine for 4 weeks. Expression of neuronal nuclear antigen (NeuN; a neuronal marker) and Fluoro-Jade B (a marker for the localization of neuronal degeneration) was also detected. After scopolamine treatment, mouse hippocampal neurons did not die, and Ki-67 (a marker for proliferating cells)-immunoreactive cells were reduced in number and reached the lowest level at 4 weeks. Doublecortin (DCX; a marker for newly generated neurons)-immunoreactive cells were gradually shortened in length and reduced in number with time. After scopolamine treatment for 4 weeks, nearly all of the 5-bromo-2'-deoxyuridine (BrdU)-labeled newly generated cells were located in the subgranular zone of the dentate gyrus, but they did not migrate into the granule cell layer. Few mature BrdU/NeuN double-labeled cells were seen in the subgranular zone of the dentate gyrus. These findings suggest that long-term administration of scopolamine interferes with the proliferation, differentiation and migration of nerve cells in the adult mouse hippocampal dentate gyrus, but it does not induce cell death.
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Affiliation(s)
- Bing Chun Yan
- Department of Integrative Traditional & Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu Province, China
| | - Joon Ha Park
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Bai Hui Chen
- Department of Physiology, College of Medicine, Institute of Neurodegeneration and Neuroregeneration, Hallym University, Chuncheon, South Korea
| | - Jeong-Hwi Cho
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - In Hye Kim
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Ji Hyeon Ahn
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Jae-Chul Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Jun Hwi Cho
- Department of Emergency Medicine, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Yun Lyul Lee
- Department of Physiology, College of Medicine, Institute of Neurodegeneration and Neuroregeneration, Hallym University, Chuncheon, South Korea
| | - Il-Jun Kang
- Department of Food Science and Nutrition, Hallym University, Chuncheon, South Korea
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, South Korea
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Sohn EJ, Shin MJ, Kim DW, Ahn EH, Jo HS, Kim DS, Cho SW, Han KH, Park J, Eum WS, Hwang HS, Choi SY. Tat-fused recombinant human SAG prevents dopaminergic neurodegeneration in a MPTP-induced Parkinson's disease model. Mol Cells 2014; 37:226-33. [PMID: 24625574 PMCID: PMC3969043 DOI: 10.14348/molcells.2014.2314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/18/2014] [Accepted: 01/27/2014] [Indexed: 02/03/2023] Open
Abstract
Excessive reactive oxygen species (ROS) generated from abnormal cellular process lead to various human diseases such as inflammation, ischemia, and Parkinson's disease (PD). Sensitive to apoptosis gene (SAG), a RING-FINGER protein, has anti-apoptotic activity and anti-oxidant activity. In this study, we investigate whether Tat-SAG, fused with a Tat domain, could protect SH-SY5Y neuroblastoma cells against 1-methyl-4-phenylpyridinium (MPP(+)) and dopaminergic (DA) neurons in the substantia nigra (SN) against 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine (MPTP) toxicity. Western blot and immunohistochemical analysis showed that, unlike SAG, Tat-SAG transduced efficiently into SH-SY5Y cells and into the brain, respectively. Tat-SAG remarkably suppressed ROS generation, DNA damage, and the progression of apoptosis, caused by MPP(+) in SH-SY5Y cells. Also, immunohistochemical data using a tyrosine hydroxylase antibody and cresyl violet staining demonstrated that Tat-SAG obviously protected DA neurons in the SN against MPTP toxicity in a PD mouse model. Tat-SAG-treated mice showed significant enhanced motor activities, compared to SAG- or Tat-treated mice. Therefore, our results suggest that Tat-SAG has potential as a therapeutic agent against ROS-related diseases such as PD.
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Affiliation(s)
- Eun Jeong Sohn
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Min Jea Shin
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Kangnung-Wonju National University, Gangneung 210-702,
Korea
| | - Eun Hee Ahn
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Hyo Sang Jo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Duk-Soo Kim
- Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan 330-090,
Korea
| | - Sung-Woo Cho
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736,
Korea
| | - Kyu Hyung Han
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Jinseu Park
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Won Sik Eum
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Hyun Sook Hwang
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
| | - Soo Young Choi
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702,
Korea
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Chen BH, Yan BC, Park JH, Ahn JH, Lee DH, Kim IH, Cho JH, Lee JC, Kim SK, Lee B, Cho JH, Won MH, Lee YL. Aripiprazole, an atypical antipsychotic drug, improves maturation and complexity of neuroblast dendrites in the mouse dentate gyrus via increasing superoxide dismutases. Neurochem Res 2013; 38:1980-8. [PMID: 23836293 DOI: 10.1007/s11064-013-1104-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 01/02/2023]
Abstract
Apripiprazole (APZ) is well known as an atypical antipsychotic and antidepressant. In the present study, we investigated effects of APZ on cell proliferation and neuronal differentiation in the dentate gyrus (DG) of the adolescent mouse using BruU, Ki-67 and doublecortin (DCX) immunohistochemistry. BruU, Ki-67 and DCX-positive (+) cells were easily detected in the subgranular zone of the DG in the vehicle- and APZ-treated group. We found that in the 8 mg/kg APZ-treated group numbers of Ki-67(+), DCX(+) and BrdU(+)/DCX(+) cells were significantly increased compared with those in the vehicle-treated group. We also found that maturation and complexity of DCX(+) dendrites in the 8 mg/kg APZ-treated group was well improved compared with those in the vehicle-treated group. In addition, markedly decreased lipid peroxidation and increased superoxide dismutase 2 (SOD2) level were observed in the DG of the 8 mg/kg APZ-treated group. Our present findings indicate that APZ can enhance cell proliferation and neuroblast differentiation, particularly maturation and complexity of neuroblast dendrites, in the DG via decreasing lipid peroxidation and increasing SOD2 level.
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Affiliation(s)
- Bai Hui Chen
- Department of Physiology, Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon, 200-702, South Korea
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Sun Y, Li H. Functional characterization of SAG/RBX2/ROC2/RNF7, an antioxidant protein and an E3 ubiquitin ligase. Protein Cell 2012; 4:103-16. [PMID: 23136067 DOI: 10.1007/s13238-012-2105-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 10/09/2012] [Indexed: 01/28/2023] Open
Abstract
SAG (Sensitive to Apoptosis Gene), also known as RBX2 (RING box protein 2), ROC2 (Regulator of Cullins 2), or RNF7 (RING Finger Protein 7), was originally cloned in our laboratory as a redox inducible antioxidant protein and later characterized as the second member of the RBX/ROC RING component of the SCF (SKP1-CUL-F-box Proteins) E3 ubiquitin ligase. When acting alone, SAG scavenges oxygen radicals by forming inter- and intra-molecular disulfide bonds, whereas by forming a complex with other components of the SCF E3 ligase, SAG promotes ubiquitination and degradation of a number of protein substrates, including c-JUN, DEPTOR, HIF-1α, IκBα, NF1, NOXA, p27, and procaspase-3, thus regulating various signaling pathways and biological processes. Specifically, SAG protects cells from apoptosis, confers radioresistance, and plays an essential and non-redundant role in mouse embryogenesis and vasculogenesis. Furthermore, stress-inducible SAG is overexpressed in a number of human cancers and SAG overexpression correlates with poor patient prognosis. Finally, SAG transgenic expression in epidermis causes an early stage inhibition, but later stage promotion, of skin tumorigenesis triggered by DMBA/TPA. Given its major role in promoting targeted degradation of tumor suppressive proteins, leading to apoptosis suppression and accelerated tumorigenesis, SAG E3 ligase appears to be an attractive anticancer target.
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Affiliation(s)
- Yi Sun
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, 4424B Medical Science-I, 1301 Catherine Street, Ann Arbor, MI 48109, USA.
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