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Roy S, Batra L. Protein Phosphatase 2A: Role in T Cells and Diseases. J Immunol Res 2023; 2023:4522053. [PMID: 37234102 PMCID: PMC10208765 DOI: 10.1155/2023/4522053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a serine-threonine phosphatase that plays an important role in the regulation of cell proliferation and signal transduction. The catalytic activity of PP2A is integral in the maintenance of physiological functions which gets severely impaired in its absence. PP2A plays an essential role in the activation, differentiation, and functions of T cells. PP2A suppresses Th1 cell differentiation while promoting Th2 cell differentiation. PP2A fosters Th17 cell differentiation which contributes to the pathogenesis of systemic lupus erythematosus (SLE) by enhancing the transactivation of the Il17 gene. Genetic deletion of PP2A in Tregs disrupts Foxp3 expression due to hyperactivation of mTORC1 signaling which impairs the development and immunosuppressive functions of Tregs. PP2A is important in the induction of Th9 cells and promotes their antitumor functions. PP2A activation has shown to reduce neuroinflammation in a mouse model of experimental autoimmune encephalomyelitis (EAE) and is now used to treat multiple sclerosis (MS) clinically. In this review, we will discuss the structure and functions of PP2A in T cell differentiation and diseases and therapeutic applications of PP2A-mediated immunotherapy.
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Affiliation(s)
- Suyasha Roy
- Immuno-Biology Laboratory, Translational Health Science and Technology Institute, Faridabad, India
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lalit Batra
- Regional Biocontainment Laboratory, Center for Predictive Medicine, University of Louisville, Louisville, KY, USA
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2
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Chen B, Hu H, Chen X. From Basic Science to Clinical Practice: The Role of Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A)/p90 in Cancer. Front Genet 2023; 14:1110656. [PMID: 36911405 PMCID: PMC9998691 DOI: 10.3389/fgene.2023.1110656] [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: 11/29/2022] [Accepted: 02/03/2023] [Indexed: 03/14/2023] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A), initially reported as a tumor-associated antigen (known as p90), is highly expressed in most solid and hematological tumors. The interaction of CIP2A/p90, protein phosphatase 2A (PP2A), and c-Myc can hinder the function of PP2A toward c-Myc S62 induction, thus stabilizing c-Myc protein, which represents a potential role of CIP2A/p90 in tumorigeneses such as cell proliferation, invasion, and migration, as well as cancer drug resistance. The signaling pathways and regulation networks of CIP2A/p90 are complex and not yet fully understood. Many previous studies have also demonstrated that CIP2A/p90 can be used as a potential therapeutic cancer target. In addition, the autoantibody against CIP2A/p90 in sera may be used as a promising biomarker in the diagnosis of certain types of cancer. In this Review, we focus on recent advances relating to CIP2A/p90 and their implications for future research.
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Affiliation(s)
- Beibei Chen
- Department of Medical Oncology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan, China.,Zhengzhou Key Laboratory for Precision Therapy of Gastrointestinal Cancer, Zhengzhou, Henan, China
| | - Huihui Hu
- Department of Medical Oncology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan, China.,Zhengzhou Key Laboratory for Precision Therapy of Gastrointestinal Cancer, Zhengzhou, Henan, China
| | - Xiaobing Chen
- Department of Medical Oncology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan, China.,Zhengzhou Key Laboratory for Precision Therapy of Gastrointestinal Cancer, Zhengzhou, Henan, China
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3
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Kashani E, Vassella E. Pleiotropy of PP2A Phosphatases in Cancer with a Focus on Glioblastoma IDH Wildtype. Cancers (Basel) 2022; 14:5227. [PMID: 36358647 PMCID: PMC9654311 DOI: 10.3390/cancers14215227] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/13/2022] [Accepted: 10/20/2022] [Indexed: 07/29/2023] Open
Abstract
Serine/Threonine protein phosphatase 2A (PP2A) is a heterotrimeric (or occasionally, heterodimeric) phosphatase with pleiotropic functions and ubiquitous expression. Despite the fact that they all contribute to protein dephosphorylation, multiple PP2A complexes exist which differ considerably by their subcellular localization and their substrate specificity, suggesting diverse PP2A functions. PP2A complex formation is tightly regulated by means of gene expression regulation by transcription factors, microRNAs, and post-translational modifications. Furthermore, a constant competition between PP2A regulatory subunits is taking place dynamically and depending on the spatiotemporal circumstance; many of the integral subunits can outcompete the rest, subjecting them to proteolysis. PP2A modulation is especially important in the context of brain tumors due to its ability to modulate distinct glioma-promoting signal transduction pathways, such as PI3K/Akt, Wnt, Ras, NF-κb, etc. Furthermore, PP2A is also implicated in DNA repair and survival pathways that are activated upon treatment of glioma cells with chemo-radiation. Depending on the cancer cell type, preclinical studies have shown some promise in utilising PP2A activator or PP2A inhibitors to overcome therapy resistance. This review has a special focus on "glioblastoma, IDH wild-type" (GBM) tumors, for which the therapy options have limited efficacy, and tumor relapse is inevitable.
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Affiliation(s)
- Elham Kashani
- Institute of Pathology, University of Bern, 3008 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Erik Vassella
- Institute of Pathology, University of Bern, 3008 Bern, Switzerland
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4
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Hasanin R, Mossallam G, Elfishawi S, Rabea A, Hamdy N. Overexpression of cancerous inhibitor of PP2A ( CIP2A) in acute myeloid leukemia. Expert Rev Hematol 2022; 15:465-471. [PMID: 35502616 DOI: 10.1080/17474086.2022.2072825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy. Protein phosphatase 2A Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase and tumor suppressor that negatively regulates numerous signal transduction pathways. Cancerous inhibitor of PP2A (CIP2A) is an endogenous inhibitor of PP2A. CIP2A overexpression was shown to be a recurrent event in cytogenetic normal AML patients. The aim of the study is to evaluate the prognostic significance of CIP2A overexpression in patients with AML. RESEARCH DESIGN AND METHODS The study included 174 newly diagnosed cytogenetic normal AML patients. Detection of CIP2A expression was performed using quantitative real-time PCR. RESULTS CIP2A was overexpressed in 125/174 (71.8%) of patients. Correlation of CIP2A overexpression with other prognostic factors showed significant association with CD34 expression (p=0.04). CIP2A overexpression was significantly associated with a lower rate of (complete remission) CR (p=0.019) and shorter disease free survival (DFS) and overall survival (OS) (p<0.001 and <0.001, respectively). In multivariate analysis, CIP2A overexpression was an independent adverse prognostic factor that negatively affected DFS and OS (p<0.001, HR:2.8,95%CI:1.7-4.7 and p=0.002, HR:1.8; 95%CI:1.2-2.65, respectively). CONCLUSION CIP2A overexpression is a useful prognostic marker in AML.
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Affiliation(s)
- Reem Hasanin
- Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Ghada Mossallam
- Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Sally Elfishawi
- Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Ahmed Rabea
- Department of Medical Oncology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Nayera Hamdy
- Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
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Shafik RE, Ibrahim AM, Said F, Hassan NM, Shafik HE, Shokralla HA. Prognostic value of CIP2A gene expression in adult Egyptian acute myeloid leukemia patients. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2020. [DOI: 10.1186/s43042-020-00075-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Abstract
Background
Protein phosphatase 2A (PP2A) functions as a tumor suppressor in many cancers. Cancerous inhibitor of protein phosphatase 2A (CIP2A) inhibits PP2A proteolytic degradation of c-Myc and enhances cell growth and tumor formation in several tissues. CIP2A expression in acute myeloid leukemia (AML) and its effect on outcome of treatment were not reported in Egyptian patients.
Results
No significant difference was detected in CIP2A expression between AML and control groups (P = 0.48). However, in AML patients, those with low CIP2A expression had a longer median overall survival than those with high expression (P = 0.059). CIP2A expression was not related to the clinical and laboratory variables and did not affect response to treatment.
Conclusion
High-CIP2A expression was associated with a trend of shorter overall survival in adult Egyptian AML patients. It might serve as a useful marker to predict poor prognosis. CIP2A may represent a potential target for cancer therapy.
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Ji J, Zhen W, Si Y, Ma W, Zheng L, Li C, Zhang Y, Qin S, Zhang T, Liu P, Zheng X, Liu Y. Increase in CIP2A expression is associated with cisplatin chemoresistance in gastric cancer. Cancer Biomark 2018; 21:307-316. [PMID: 29103022 DOI: 10.3233/cbm-170416] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein which involves in the progression of several human malignancies. Development of cisplatin (DDP) resistance is the obstacle to an effective control of gastric cancer (GC) clinically. OBJECTIVE We thus assessed whether CIP2A expression is associated with sensitivity of GC to DDP. METHODS Real-time quantitative PCR, immunohistochemical analysis, or western blotting was performed to detect CIP2A expression in GC patients' tissues. SGC7901/DDP cells were transfected with CIP2A siRNA. MTT assay was used to determine the DDP-sensitivity of cells. Flow cytometry was used to measure cell apoptosis. RESULTS CIP2A has higher expression in DDP-resistant GC patients. DDP-resistant GC patients with high CIP2A expression presented with poorer overall survival rates than those with low CIP2A expression. CIP2A knockdown in DDP-resistant GC cells resulted in attenuated proliferative abilities and increased apoptosis level. CIP2A depletion sensitizes DDP-resistant cells to DDP and CIP2A overexpression antagonizes DDP-sensitive cells to DDP. CIP2A influences the expression of multidrug resistance-related proteins in GC cells. CONCLUSIONS Our results suggested that CIP2A oncoprotein plays an important role in DDP resistance of GC and could serve as a novel therapeutic target for the treatment of GC patients with DDP resistance.
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Affiliation(s)
- Juanli Ji
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China.,School of Biomedical Engineering, Hubei University of Medicine, Shiyan, Hubei 442000, China.,Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Weiguo Zhen
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China.,Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Yuan Si
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Wenjing Ma
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China.,School of Biomedical Engineering, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Lanlan Zheng
- Laboratory of Medicinal Plant, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Chen Li
- Laboratory of Medicinal Plant, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Yonghong Zhang
- Laboratory of Medicinal Plant, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Shanshan Qin
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Te Zhang
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Pengfei Liu
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China.,School of Biomedical Engineering, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Xin Zheng
- Department of Gastrointestinal Surgery, Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Ying Liu
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, China
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7
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The role of CIP2A in cancer: A review and update. Biomed Pharmacother 2017; 96:626-633. [DOI: 10.1016/j.biopha.2017.08.146] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/01/2017] [Accepted: 08/13/2017] [Indexed: 12/11/2022] Open
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Baldacchino S, Wastall LM, Saliba C, Hughes TA, Scerri C, Berwick A, Speirs V, Hanby AM, Grech G. CIP2A expression predicts recurrences of tamoxifen-treated breast cancer. Tumour Biol 2017; 39:1010428317722064. [PMID: 29034804 DOI: 10.1177/1010428317722064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
CIP2A is emerging as an oncoprotein overexpressed commonly across many tumours and generally correlated with higher tumour grade and therapeutic resistance. CIP2A drives an oncogenic potential through inhibiting protein phosphatase 2A, stabilizing MYC, and promoting epithelial-to-mesenchymal transition, although further biological mechanisms for CIP2A are yet to be defined. CIP2A protein expression was studied by immunohistochemistry in oestrogen receptor-positive primary breast cancers (n = 250) obtained from the Leeds Tissue Bank. In total, 51 cases presented with a relapse or metastasis during adjuvant treatment with tamoxifen and were regarded as tamoxifen resistant. CIP2A expression was scored separately for cytoplasmic, nuclear, or membranous staining, and scores were tested for statistically significant relationships with clinicopathological features. Membranous CIP2A was preferentially expressed in cases who experienced a recurrence during tamoxifen treatment thus predicting a worse overall survival (log rank = 8.357, p = 0.004) and disease-free survival (log rank = 21.766, p < 0.001). Cox multivariate analysis indicates that it is an independent prognostic indicator for overall survival (hazard ratio = 4.310, p = 0.013) and disease-free survival (hazard ratio = 5.449, p = 0.002). In this study, we propose the assessment of membranous CIP2A expression as a potential novel prognostic and predictive indicator for tamoxifen resistance and recurrence within oestrogen receptor-positive breast cancer.
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Affiliation(s)
- Shawn Baldacchino
- 1 Laboratory of Molecular Pathology, Department of Pathology, Faculty of Medicine & Surgery, University of Malta, Msida, Malta
| | - Laura M Wastall
- 2 School of Medicine, University of Leeds, Leeds, UK.,3 Department of Cellular Pathology, St James's University Hospital, Leeds, UK
| | - Christian Saliba
- 4 Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | | | - Christian Scerri
- 5 Department of Physiology & Biochemistry, Faculty of Medicine & Surgery, University of Malta, Msida, Malta
| | - Angelene Berwick
- 6 Leeds Institute of Cancer & Pathology, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Valerie Speirs
- 6 Leeds Institute of Cancer & Pathology, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Andrew M Hanby
- 3 Department of Cellular Pathology, St James's University Hospital, Leeds, UK.,6 Leeds Institute of Cancer & Pathology, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Godfrey Grech
- 1 Laboratory of Molecular Pathology, Department of Pathology, Faculty of Medicine & Surgery, University of Malta, Msida, Malta
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Liu X, Cao W, Qin S, Zhang T, Zheng J, Dong Y, Ming P, Cheng Q, Lu Z, Guo Y, Zhang B, Liu Y. Overexpression of CIP2A is associated with poor prognosis in multiple myeloma. Signal Transduct Target Ther 2017; 2:17013. [PMID: 29263916 PMCID: PMC5661621 DOI: 10.1038/sigtrans.2017.13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/04/2017] [Accepted: 03/02/2017] [Indexed: 11/09/2022] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A), an endogenous protein phosphatase 2A (PP2A) inhibitor, has been identified as an oncoprotein in promoting cancer initiation and progression of several types of cancer. However, the expression and the role played by CIP2A in the pathogenesis of multiple myeloma (MM) remain unclear. In this study, we showed that CIP2A was overexpressed in human MM cell lines and MM patients' bone marrow tissues. Clinicopathologic analysis showed that CIP2A expression was significantly correlated with clinical stage and percent of plasma cells in bone marrow. Kaplan-Meier analysis revealed that patients with high CIP2A expression presented with poorer overall survival rates than those with low CIP2A expression. Moreover, CIP2A knockdown in MM cells resulted in attenuated proliferative abilities. In addition, CIP2A depletion sensitizes dexamethasone (Dex)-resistant cells to Dex. The effect of CIP2A on proliferation and Dex therapy was mediated by the inhibition of PP2A, which in turn activated Akt. In vivo studies confirmed that CIP2A regulated MM tumorigenesis and the phosphorylation of Akt. Taken together, our results suggest that CIP2A oncoprotein plays an important role in MM progression and could serve as a prognosis marker and a novel therapeutic target for the treatment of patients with MM.
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Affiliation(s)
- Xuewen Liu
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences; Hubei University of Medicine, Shiyan, China
| | - Wei Cao
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Shanshan Qin
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences; Hubei University of Medicine, Shiyan, China
| | - Te Zhang
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences; Hubei University of Medicine, Shiyan, China
| | - Junnian Zheng
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Ying Dong
- Department of Oncology, The Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Pinghong Ming
- Department of Pathology, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Qian Cheng
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Zheng Lu
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Yang Guo
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences; Hubei University of Medicine, Shiyan, China
| | - Baofu Zhang
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Ying Liu
- Laboratory of Molecular Target Therapy of Cancer, Institute of Basic Medical Sciences; Hubei University of Medicine, Shiyan, China
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Liu CY, Hsieh FS, Chu PY, Tsai WC, Huang CT, Yu YB, Huang TT, Ko PS, Hung MH, Wang WL, Shiau CW, Chen KF. Carfilzomib induces leukaemia cell apoptosis via inhibiting ELK1/KIAA1524 (Elk-1/CIP2A) and activating PP2A not related to proteasome inhibition. Br J Haematol 2017; 177:726-740. [PMID: 28340282 DOI: 10.1111/bjh.14620] [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] [Received: 10/02/2016] [Accepted: 12/22/2016] [Indexed: 01/23/2023]
Abstract
Enhancing the tumour suppressive activity of protein phosphatase 2A (PP2A) has been suggested to be an anti-leukaemic strategy. KIAA1524 (also termed CIP2A), an oncoprotein inhibiting PP2A, is associated with disease progression in chronic myeloid leukaemia and may be prognostic in cytogenetically normal acute myeloid leukaemia. Here we demonstrated that the selective proteasome inhibitor, carfilzomib, induced apoptosis in sensitive primary leukaemia cells and in sensitive leukaemia cell lines, associated with KIAA1524 protein downregulation, increased PP2A activity and decreased p-Akt, but not with the proteasome inhibition effect of carfilzomib. Ectopic expression of KIAA1524, or pretreatment with the PP2A inhibitor, okadaic acid, suppressed carfilzomib-induced apoptosis and KIAA1524 downregulation in sensitive cells, whereas co-treatment with the PP2A agonist, forskolin, enhanced carfilzomib-induced apoptosis in resistant cells. Mechanistically, carfilzomib affected KIAA1524 transcription through disturbing ELK1 (Elk-1) binding to the KIAA1524 promoter. Moreover, the drug sensitivity and mechanism of carfilzomib in xenograft mouse models correlated well with the effects of carfilzomib on KIAA1524 and p-Akt expression, as well as PP2A activity. Our data disclosed a novel drug mechanism of carfilzomib in leukaemia cells and suggests the potential therapeutic implication of KIAA1524 in leukaemia treatment.
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Affiliation(s)
- Chun-Yu Liu
- Comprehensive Breast Health Centre, Taipei Veterans General Hospital, Taipei, Taiwan.,Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Haematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Feng-Shu Hsieh
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Pei-Yi Chu
- Department of Pathology, Show Chwan Memorial Hospital, Changhua, Taiwan.,School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Wen-Chun Tsai
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chun-Teng Huang
- School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Haematology and Oncology, Department of Medicine, Yang-Ming Branch of Taipei City Hospital, Taipei, Taiwan
| | - Yuan-Bin Yu
- School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Haematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Tzu-Ting Huang
- Comprehensive Breast Health Centre, Taipei Veterans General Hospital, Taipei, Taiwan.,Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Po-Shen Ko
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Haematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Man-Hsin Hung
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Haematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wan-Lun Wang
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chung-Wai Shiau
- Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Kuen-Feng Chen
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan.,National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan
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11
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Li S, Feng TT, Guo Y, Yu X, Huang Q, Zhang L, Tang W, Liu Y. Expression of cancerous inhibitor of protein phosphatase 2A in human triple negative breast cancer correlates with tumor survival, invasion and autophagy. Oncol Lett 2016; 12:5370-5376. [PMID: 28101248 DOI: 10.3892/ol.2016.5374] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently characterized oncoprotein which is involved in the progression of several human malignancies. The present study aimed to investigate its biological function in human triple negative breast cancer (TNBC). The expression of CIP2A in TNBC cells was examined and it was observed that CIP2A was elevated in the TNBC cell line compared with poorly invasive breast cancer cells. CIP2A depletion in TNBC cell lines inhibited proliferation, and induced apoptosis and autophagy. In addition, CIP2A depletion inhibited invasion and migration of TNBC cells. Furthermore, CIP2A depletion downregulated Akt/mTOR/P70S6K phosphorylation. These results validate the role of CIP2A as a invasion-associated oncoprotein and established CIP2A as a promising therapeutic target of TNBC.
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Affiliation(s)
- Shan Li
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Ting-Ting Feng
- School of Basic Medical Sciences, Anhui Medical University, Heifei, Anhui 230032, P.R. China
| | - Yang Guo
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Xianjun Yu
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Qiuyue Huang
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Liang Zhang
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Wei Tang
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Ying Liu
- Department of Biochemistry, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
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12
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Grech G, Baldacchino S, Saliba C, Grixti MP, Gauci R, Petroni V, Fenech AG, Scerri C. Deregulation of the protein phosphatase 2A, PP2A in cancer: complexity and therapeutic options. Tumour Biol 2016; 37:11691-11700. [PMID: 27444275 DOI: 10.1007/s13277-016-5145-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/11/2016] [Indexed: 01/26/2023] Open
Abstract
The complexity of the phosphatase, PP2A, is being unravelled and current research is increasingly providing information on the association of deregulated PP2A function with cancer initiation and progression. It has been reported that decreased activity of PP2A is a recurrent observation in many types of cancer, including colorectal and breast cancer (Baldacchino et al. EPMA J. 5:3, 2014; Cristobal et al. Mol Cancer Ther. 13:938-947, 2014). Since deregulation of PP2A and its regulatory subunits is a common event in cancer, PP2A is a potential target for therapy (Baldacchino et al. EPMA J. 5:3, 2014). In this review, the structural components of the PP2A complex are described, giving an in depth overview of the diversity of regulatory subunits. Regulation of the active PP2A trimeric complex, through phosphorylation and methylation, can be targeted using known compounds, to reactivate the complex. The endogenous inhibitors of the PP2A complex are highly deregulated in cancer, representing cases that are eligible to PP2A-activating drugs. Pharmacological opportunities to target low PP2A activity are available and preclinical data support the efficacy of these drugs, but clinical trials are lacking. We highlight the importance of PP2A deregulation in cancer and the current trends in targeting the phosphatase.
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Affiliation(s)
- Godfrey Grech
- Department of Pathology, Faculty of Medicine & Surgery, Medical School, University of Malta, Msida, MSD2090, Malta.
| | - Shawn Baldacchino
- Department of Pathology, Faculty of Medicine & Surgery, Medical School, University of Malta, Msida, MSD2090, Malta
| | - Christian Saliba
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Maria Pia Grixti
- Department of Pathology, Faculty of Medicine & Surgery, Medical School, University of Malta, Msida, MSD2090, Malta
| | - Robert Gauci
- Department of Pathology, Faculty of Medicine & Surgery, Medical School, University of Malta, Msida, MSD2090, Malta
| | - Vanessa Petroni
- Department of Anatomy, Faculty of Medicine & Surgery, University of Malta, Msida, Malta
| | - Anthony G Fenech
- Department of Clinical Pharmacology & Therapeutics, Faculty of Medicine & Surgery, University of Malta, Msida, Malta
| | - Christian Scerri
- Department of Physiology and Biochemistry, Faculty of Medicine & Surgery, University of Malta, Msida, Malta.,Molecular Genetics Clinic, Mater Dei Hospital, Msida, Malta
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13
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Côme C, Cvrljevic A, Khan MM, Treise I, Adler T, Aguilar-Pimentel JA, Au-Yeung B, Sittig E, Laajala TD, Chen Y, Oeder S, Calzada-Wack J, Horsch M, Aittokallio T, Busch DH, Ollert MW, Neff F, Beckers J, Gailus-Durner V, Fuchs H, de Angelis MH, Chen Z, Lahesmaa R, Westermarck J. CIP2A Promotes T-Cell Activation and Immune Response to Listeria monocytogenes Infection. PLoS One 2016; 11:e0152996. [PMID: 27100879 PMCID: PMC4839633 DOI: 10.1371/journal.pone.0152996] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 03/22/2016] [Indexed: 11/18/2022] Open
Abstract
The oncoprotein Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) is overexpressed in most malignancies and is an obvious candidate target protein for future cancer therapies. However, the physiological importance of CIP2A-mediated PP2A inhibition is largely unknown. As PP2A regulates immune responses, we investigated the role of CIP2A in normal immune system development and during immune response in vivo. We show that CIP2A-deficient mice (CIP2AHOZ) present a normal immune system development and function in unchallenged conditions. However when challenged with Listeria monocytogenes, CIP2AHOZ mice display an impaired adaptive immune response that is combined with decreased frequency of both CD4+ T-cells and CD8+ effector T-cells. Importantly, the cell autonomous effect of CIP2A deficiency for T-cell activation was confirmed. Induction of CIP2A expression during T-cell activation was dependent on Zap70 activity. Thus, we reveal CIP2A as a hitherto unrecognized mediator of T-cell activation during adaptive immune response. These results also reveal CIP2AHOZ as a possible novel mouse model for studying the role of PP2A activity in immune regulation. On the other hand, the results also indicate that CIP2A targeting cancer therapies would not cause serious immunological side-effects.
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Affiliation(s)
- Christophe Côme
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- * E-mail:
| | - Anna Cvrljevic
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Mohd Moin Khan
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Turku Doctoral Programme of Molecular Medicine (TuDMM), Medical Faculty, University of Turku, Turku, Finland
| | - Irina Treise
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Thure Adler
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
| | - Juan Antonio Aguilar-Pimentel
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Department of Dermatology and Allergy, Biederstein, Klinikum rechts der Isar, Technische Universität München (TUM), Munich, Germany
| | - Byron Au-Yeung
- Howard Hughes Medical Institute, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Eleonora Sittig
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Teemu Daniel Laajala
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Mathematics and Statistics, University of Turku, Turku, Finland
| | - Yiling Chen
- Howard Hughes Medical Institute, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Sebastian Oeder
- Center of Allergy and Environment Munich (ZAUM), Technische Universität München (TUM), and Institute for Allergy Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich/Neuherberg, Germany
- Kühne Foundation, Christine Kühne Center for Allergy Research and Education (CK-CARE), Munich, Germany
| | - Julia Calzada-Wack
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Marion Horsch
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Dirk H. Busch
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
| | - Markus W. Ollert
- Clinical Research Group Molecular Allergology, Center of Allergy and Environment Munich (ZAUM), Technische Universität München (TUM), and Institute for Allergy Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich/Neuherberg, Germany
| | - Frauke Neff
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Johannes Beckers
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Chair of Experimental Genetics, Center for Life and Food Sciences Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Zhi Chen
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Riitta Lahesmaa
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Jukka Westermarck
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Pathology, University of Turku, Turku, Finland
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14
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Xiao X, He Z, Cao W, Cai F, Zhang L, Huang Q, Fan C, Duan C, Wang X, Wang J, Liu Y. Oridonin inhibits gefitinib-resistant lung cancer cells by suppressing EGFR/ERK/MMP-12 and CIP2A/Akt signaling pathways. Int J Oncol 2016; 48:2608-18. [PMID: 27082429 DOI: 10.3892/ijo.2016.3488] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/24/2016] [Indexed: 11/06/2022] Open
Abstract
Oridonin (Ori), a diterpenoid compound extracted from traditional medicinal herbs, elicits antitumor effects on many cancer types. However, whether Ori can be used in gefitinib-resistant non-small cell lung cancer (NSCLC) cells remains unclear. This study investigated the antitumor activity and underlying mechanisms of Ori. Results demonstrated that this compound dose-dependently inhibited the proliferation, invasion, and migration of the gefitinib-resistant NSCLC cells in vitro. Ori also significantly downregulated the phosphorylation of EGFR, ERK, Akt, expression levels of matrix metalloproteinase-12 (MMP-12), and the cancerous inhibitor of protein phosphatase 2A (CIP2A). In addition, Ori upregulated protein phosphatase 2A (PP2A) activity of gefitinib-resistant NSCLC cells. Ori combined with docetaxel synergistically inhibited these cells. Ori also inhibited tumor growth in murine models. Immunohistochemistry results further revealed that Ori downregulated phospho-EGFR, MMP-12, and CIP2A in vivo. These findings indicated that Ori can inhibit the proliferation, invasion, and migration of gefitinib-resistant NSCLC cells by suppressing EGFR/ERK/MMP-12 and CIP2A/PP2A/Akt signaling pathways. Thus, Ori may be a novel effective candidate to treat gefitinib-resistant NSCLC.
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Affiliation(s)
- Xiangling Xiao
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Zhongwei He
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Wei Cao
- School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China
| | - Fen Cai
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Liang Zhang
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Qiuyue Huang
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Chunsheng Fan
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Chao Duan
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Xiaobo Wang
- Translational Medical Center, Suizhou Central Hospital, Hubei University of Medicine, Suizhou, Hubei 441300, P.R. China
| | - Jiu Wang
- School of Pharmaceutical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Ying Liu
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
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15
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Arriazu E, Pippa R, Odero MD. Protein Phosphatase 2A as a Therapeutic Target in Acute Myeloid Leukemia. Front Oncol 2016; 6:78. [PMID: 27092295 PMCID: PMC4822158 DOI: 10.3389/fonc.2016.00078] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/21/2016] [Indexed: 12/31/2022] Open
Abstract
Acute myeloid leukemia (AML) is a heterogeneous malignant disorder of hematopoietic progenitor cells in which several genetic and epigenetic aberrations have been described. Despite progressive advances in our understanding of the molecular biology of this disease, the outcome for most patients is poor. It is, therefore, necessary to develop more effective treatment strategies. Genetic aberrations affecting kinases have been widely studied in AML; however, the role of phosphatases remains underexplored. Inactivation of the tumor-suppressor protein phosphatase 2A (PP2A) is frequent in AML patients, making it a promising target for therapy. There are several PP2A inactivating mechanisms reported in this disease. Deregulation or specific post-translational modifications of PP2A subunits have been identified as a cause of PP2A malfunction, which lead to deregulation of proliferation or apoptosis pathways, depending on the subunit affected. Likewise, overexpression of either SET or cancerous inhibitor of protein phosphatase 2A, endogenous inhibitors of PP2A, is a recurrent event in AML that impairs PP2A activity, contributing to leukemogenesis progression. Interestingly, the anticancer activity of several PP2A-activating drugs (PADs) depends on interaction/sequestration of SET. Preclinical studies show that pharmacological restoration of PP2A activity by PADs effectively antagonizes leukemogenesis, and that these drugs have synergistic cytotoxic effects with conventional chemotherapy and kinase inhibitors, opening new possibilities for personalized treatment in AML patients, especially in cases with SET-dependent inactivation of PP2A. Here, we review the role of PP2A as a druggable tumor suppressor in AML.
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Affiliation(s)
- Elena Arriazu
- Hematology/Oncology Program, Center for Applied Medical Research (CIMA), University of Navarra , Pamplona , Spain
| | - Raffaella Pippa
- Centre for Gene Regulation and Expression, University of Dundee , Dundee , UK
| | - María D Odero
- Hematology/Oncology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain; Department of Biochemistry and Genetics, University of Navarra, Pamplona, Spain; Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
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16
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CIP2A is associated with multidrug resistance in cervical adenocarcinoma by a P-glycoprotein pathway. Tumour Biol 2015; 37:2673-82. [PMID: 26404133 DOI: 10.1007/s13277-015-4032-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/01/2015] [Indexed: 12/13/2022] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein. Here, we investigated its role in the formation of multidrug resistance (MDR) of cervical adenocarcinoma in vitro and in vivo. MTT assay showed that knockdown of CIP2A expression increased the drug sensitivity of HeLa and Dox-resistant HeLa cells (HeLa-Dox) to doxorubicin, cisplatin, and paclitaxel significantly, while overexpression of CIP2A decreased the sensitivity of HeLa cells to chemo-drugs dramatically. When treated with different chemotherapeutics, CIP2A and P-glycoprotein (P-gp) protein levels were increased in HeLa cells simultaneously. In accordance with it, knockdown or overexpression of CIP2A expression inhibited or increased the P-gp expression in the transcription level separately. The effects of CIP2A on P-gp expression was achieved partly through its regulation on the transcription factor E2F1. Moreover, the interference of CIP2A could decrease the P-gp protein activity elucidated by Rhodamine 123 (Rh123) efflux assay in HeLa and HeLa/Dox cells. In the in vivo level, confocal microscopy data demonstrated the strong co-localization of CIP2A and P-gp protein in HeLa cells, and CIP2A protein expression was significantly associated with that of P-gp in cervical adenocarcinoma tissues. Thus, CIP2A is involved in regulating multidrug resistance of cervical adenocarcinoma upon chemotherapy by enhancing P-gp expression through E2F1. CIP2A may be an attractive target in anticancer strategies to improve the effect of chemotherapy in cervical adenocarcinoma.
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17
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Lucas CM, Harris RJ, Holcroft AK, Scott LJ, Carmell N, McDonald E, Polydoros F, Clark RE. Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients. Leukemia 2015; 29:1514-23. [PMID: 25765543 DOI: 10.1038/leu.2015.71] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 12/24/2022]
Abstract
High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.
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MESH Headings
- Adult
- Aged
- Autoantigens/genetics
- Autoantigens/metabolism
- Blotting, Western
- Cell Proliferation/drug effects
- Disease Progression
- Drug Resistance, Neoplasm/drug effects
- E2F1 Transcription Factor/antagonists & inhibitors
- E2F1 Transcription Factor/genetics
- E2F1 Transcription Factor/metabolism
- Female
- Flow Cytometry
- Follow-Up Studies
- Fusion Proteins, bcr-abl/metabolism
- Humans
- Intracellular Signaling Peptides and Proteins
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/mortality
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Male
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Middle Aged
- Neoplasm Staging
- Prognosis
- Protein Kinase Inhibitors/therapeutic use
- Proto-Oncogene Proteins c-myc/metabolism
- RNA, Small Interfering/genetics
- Survival Rate
- Young Adult
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Affiliation(s)
- C M Lucas
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - R J Harris
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - A K Holcroft
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - L J Scott
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - N Carmell
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - E McDonald
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - F Polydoros
- CR-UK Liverpool Cancer Trials Unit, University of Liverpool, Liverpool, UK
| | - R E Clark
- Section of Haematology, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
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18
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Chen KF, Yen CC, Lin JK, Chen WS, Yang SH, Jiang JK, Lan YT, Lin CC, Yu HC, Hsu HM, Lin WL, Teng HW. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an independent prognostic marker in wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy. BMC Cancer 2015; 15:301. [PMID: 25896895 PMCID: PMC4404594 DOI: 10.1186/s12885-015-1300-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 03/31/2015] [Indexed: 01/07/2023] Open
Abstract
Background The impact of KRAS signaling on cancerous inhibitor of protein phosphatase 2A (CIP2A) expression has not yet been explored. We investigated the impact of KRAS on CIP2A expression in colorectal cancer patients after colorectal liver metastasectomy. Methods We examined CIP2A expression by immunohistochemistry (IHC) and used direct sequencing to identify the mutational status of KRAS exon 2 (codon 12 and 13). The association between CIP2A expression, KRAS genotype, clinicopathological parameters and survival were examined by the Kaplan–Meier method and the Cox proportional hazards model. A combination of immunoblotting and proliferation assays were employed to elucidate the role of CIP2A in signal transduction pathways in wild-type KRAS Caco-2 cells. Results A total of 220 colorectal cancer patients who had undergone colorectal liver metastasectomy were included in the study. The mutant KRAS genotype was associated with CIP2A overexpression. CIP2A expression was an independent prognostic marker in patients with wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy (relative risk = 1.873, P = 0.019). Targeted silencing of CIP2A in Caco-2 cells (wild-type KRAS) led to decreased expression of pERK/ERK and decreased cell proliferation. Overexpression of mutant KRAS G12D in Caco-2 cells led to an increase in CIP2A expression and cell proliferation. In Caco-2 cells with the KRAS G12D, KRAS overexpression preserved the regulation effect of CIP2A in KRAS and abrogated the impact of CIP2A regulation on pERK/ERK and cell proliferation. CIP2A inhibition also increased the efficacy of cetuximab in Caco-2 cells. Conclusions CIP2A is an independent prognostic marker in patients with wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy.
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Affiliation(s)
- Kuen-Feng Chen
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan. .,National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan.
| | - Chueh-Chuan Yen
- Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Jen-Kou Lin
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Wei-Shone Chen
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Shung-Haur Yang
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Jeng-Kai Jiang
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Yuan-Tzu Lan
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Chun-Chi Lin
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Hui-Chuan Yu
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan. .,National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan.
| | - Hui-Mei Hsu
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Wen-Ling Lin
- Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
| | - Hao-Wei Teng
- Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan. .,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan. .,National Yang-Ming University School of Medicine, Taipei, Taiwan.
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Zhao Y, Zhang X, Zhao Y, Kong D, Qin F, Sun J, Dong Y. Identification of potential therapeutic target genes, key miRNAs and mechanisms in acute myeloid leukemia based on bioinformatics analysis. Med Oncol 2015; 32:152. [PMID: 25832863 DOI: 10.1007/s12032-015-0572-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/13/2015] [Indexed: 11/28/2022]
Abstract
The study was aimed to explore the underlying mechanisms and identify the potential target genes and key miRNAs for acute myeloid leukemia (AML) treatment by bioinformatics analysis. The microarray data of GSE9476 were downloaded from Gene Expression Omnibus database. A total of 64 samples, including 26 AML and 38 normal samples, were used to identify differentially expressed genes (DEGs) between AML and normal samples. The functional enrichment analysis was performed, and protein-protein interaction (PPI) network of the DEGs was constructed by Cytoscape software. Besides, the target miRNAs for DEGs were identified. Totally, 323 DEGs were identified, including 87 up-regulated and 236 down-regulated genes. Not only up-regulated genes but also down-regulated genes were related to hematopoietic-related functions. Besides, down-regulated genes were also enriched in primary immunodeficiency pathway. Tumor necrosis factor (TNF), interleukin 7 receptor (IL7R), lymphocyte-specific protein tyrosine kinase (LCK), CD79a molecule and immunoglobulin-associated alpha (CD79A) were identified in these functions. TNF and LCK were hub nodes in PPI networks. miR-124 and miR-181 were important miRNAs in this study. The hematopoietic-related functions and primary immunodeficiency pathway may be associated with AML development. Genes, such as TNF, IL7R, LCK and CD79A, may be potential therapeutic target genes for AML, and miR-124 and miR-181 may be key miRNAs in AML development.
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Affiliation(s)
- Yanhong Zhao
- Department of Hematology, The First Affiliated Hospital of Harbin Medical University, No. 23, Youzheng Street, Nangang District, Harbin, 150001, China,
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Ciccone M, Calin GA, Perrotti D. From the Biology of PP2A to the PADs for Therapy of Hematologic Malignancies. Front Oncol 2015; 5:21. [PMID: 25763353 PMCID: PMC4329809 DOI: 10.3389/fonc.2015.00021] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 01/16/2015] [Indexed: 11/13/2022] Open
Abstract
Over the past decades, an emerging role of phosphatases in the pathogenesis of hematologic malignancies and solid tumors has been established. The tumor-suppressor protein phosphatase 2A (PP2A) belongs to the serine-threonine phosphatases family and accounts for the majority of serine-threonine phosphatase activity in eukaryotic cells. Numerous studies have shown that inhibition of PP2A expression and/or function may contribute to leukemogenesis in several hematological malignancies. Likewise, overexpression or aberrant expression of physiologic PP2A inhibitory molecules (e.g., SET and its associated SETBP1 and CIP2A) may turn off PP2A function and participate to leukemic progression. The discovery of PP2A as tumor suppressor has prompted the evaluation of the safety and the efficacy of new compounds, which can restore PP2A activity in leukemic cells. Although further studies are needed to better understand how PP2A acts in the intricate phosphatases/kinases cancer network, the results reviewed herein strongly support the development on new PP2A-activating drugs and the immediate introduction of those available into clinical protocols for leukemia patients refractory or resistant to current available therapies.
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Affiliation(s)
- Maria Ciccone
- Department of Experimental Therapeutics, MD Anderson Cancer Center, The University of Texas , Houston, TX , USA
| | - George A Calin
- Department of Experimental Therapeutics, MD Anderson Cancer Center, The University of Texas , Houston, TX , USA
| | - Danilo Perrotti
- Department of Medicine, The Greenebaum Cancer Center, University of Maryland School of Medicine , Baltimore, MD , USA
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Barragán E, Chillón MC, Castelló-Cros R, Marcotegui N, Prieto MI, Hoyos M, Pippa R, Llop M, Etxabe A, Cervera J, Rodríguez G, Buño I, Rifón J, Sierra J, González M, Calasanz MJ, Sanz MA, Odero MD. CIP2A high expression is a poor prognostic factor in normal karyotype acute myeloid leukemia. Haematologica 2015; 100:e183-5. [PMID: 25637054 DOI: 10.3324/haematol.2014.118117] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Eva Barragán
- Clinical Laboratory and Department of Hematology, University Hospital La Fe, Valencia, Spain
| | - María Carmen Chillón
- Department of Hematology, University Hospital of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Spain
| | | | - Nerea Marcotegui
- Program of Hematology-Oncology, CIMA, University of Navarra, Pamplona, Spain
| | - María Isabel Prieto
- Department of Hematology, University Hospital of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Spain
| | - Montserrat Hoyos
- Department of Hematology, Hospital Santa Creu i Sant Pau, Barcelona, Spain
| | - Raffaella Pippa
- Program of Hematology-Oncology, CIMA, University of Navarra, Pamplona, Spain
| | - Marta Llop
- Clinical Laboratory and Department of Hematology, University Hospital La Fe, Valencia, Spain
| | - Amaia Etxabe
- Program of Hematology-Oncology, CIMA, University of Navarra, Pamplona, Spain
| | - José Cervera
- Clinical Laboratory and Department of Hematology, University Hospital La Fe, Valencia, Spain
| | - Gabriela Rodríguez
- Department of Hematology, Gregorio Marañón Institute for Health Research, Madrid, Spain
| | - Ismael Buño
- Department of Hematology, Gregorio Marañón Institute for Health Research, Madrid, Spain
| | - José Rifón
- Department of Hematology, Clinical University of Navarra, Pamplona, Spain
| | - Jorge Sierra
- Department of Hematology, Hospital Santa Creu i Sant Pau, Barcelona, Spain
| | - Marcos González
- Department of Hematology, University Hospital of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Spain
| | - María J Calasanz
- Department of Biochemistry and Genetics, University of Navarra, Pamplona, Spain
| | - Miguel A Sanz
- Clinical Laboratory and Department of Hematology, University Hospital La Fe, Valencia, Spain
| | - María D Odero
- Program of Hematology-Oncology, CIMA, University of Navarra, Pamplona, Spain Department of Biochemistry and Genetics, University of Navarra, Pamplona, Spain
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22
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Progress in RNAi-mediated Molecular Therapy of Acute and Chronic Myeloid Leukemia. MOLECULAR THERAPY. NUCLEIC ACIDS 2015; 4:e240. [DOI: 10.1038/mtna.2015.13] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/26/2015] [Indexed: 02/08/2023]
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Haesen D, Sents W, Lemaire K, Hoorne Y, Janssens V. The Basic Biology of PP2A in Hematologic Cells and Malignancies. Front Oncol 2014; 4:347. [PMID: 25566494 PMCID: PMC4263090 DOI: 10.3389/fonc.2014.00347] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 11/20/2014] [Indexed: 12/30/2022] Open
Abstract
Reversible protein phosphorylation plays a crucial role in regulating cell signaling. In normal cells, phosphoregulation is tightly controlled by a network of protein kinases counterbalanced by several protein phosphatases. Deregulation of this delicate balance is widely recognized as a central mechanism by which cells escape external and internal self-limiting signals, eventually resulting in malignant transformation. A large fraction of hematologic malignancies is characterized by constitutive or unrestrained activation of oncogenic kinases. This is in part achieved by activating mutations, chromosomal rearrangements, or constitutive activation of upstream kinase regulators, in part by inactivation of their anti-oncogenic phosphatase counterparts. Protein phosphatase 2A (PP2A) represents a large family of cellular serine/threonine phosphatases with suspected tumor suppressive functions. In this review, we highlight our current knowledge about the complex structure and biology of these phosphatases in hematologic cells, thereby providing the rationale behind their diverse signaling functions. Eventually, this basic knowledge is a key to truly understand the tumor suppressive role of PP2A in leukemogenesis and to allow further rational development of therapeutic strategies targeting PP2A.
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Affiliation(s)
- Dorien Haesen
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Ward Sents
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Katleen Lemaire
- Gene Expression Unit, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Yana Hoorne
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation and Proteomics, Department Cellular and Molecular Medicine, University of Leuven , Leuven , Belgium
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Xia B, Tian C, Guo S, Zhang L, Zhao D, Qu F, Zhao W, Wang Y, Wu X, Da W, Wei S, Zhang Y. c-Myc plays part in drug resistance mediated by bone marrow stromal cells in acute myeloid leukemia. Leuk Res 2014; 39:92-9. [PMID: 25443862 DOI: 10.1016/j.leukres.2014.11.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/26/2014] [Accepted: 11/09/2014] [Indexed: 12/18/2022]
Abstract
Acute myeloid leukemia (AML) is a malignant and aggressive disease not sensitive to chemotherapy. The dynamic interaction between AML cells and bone marrow (BM) microenvironment plays a critical role in response of this disease to chemotherapy. It is reported that mesenchymal stromal cells (MSC) are essential component of bone marrow microenvironment which affects the survival of AML cells. The aim of our research is to elucidate the mechanism of drug resistance of AML cells associated with MSC. We found that adhesion of AML cell lines U937, KG1a and primary AML cells to MSC inhibited cytotoxic drug-induced apoptosis. Western blot showed that c-Myc of AML cells cocultured with stroma was up-regulated. Treatment with 10058-F4, a small molecule inhibitor of MYC-MAX heterodimerization, or c-Myc siRNA significantly induced apoptosis. Western blot analysis further showed that inhibition of c-Myc induced expression of caspases-3, cleavage of PARP and reduced expression of Bcl-2, Bcl-xL and vascular endothelial growth factor (VEGF). Thus, we conclude that MSCs protected leukemia cells from apoptosis, at least in part, through c-Myc dependent mechanisms, and that c-Myc contributed to microenvironment-mediated drug resistance in AML. In summary, we declared that c-Myc is a potential therapeutic target for overcoming drug resistance in AML.
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Affiliation(s)
- Bing Xia
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Chen Tian
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Shanqi Guo
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Le Zhang
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Dandan Zhao
- Department of Hematology, First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing, China
| | - Fulian Qu
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Weipeng Zhao
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Yafei Wang
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China
| | - Xiaoxiong Wu
- Department of Hematology, First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing, China
| | - Wanming Da
- Department of Hematology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Sheng Wei
- Department of Immunology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA
| | - Yizhuo Zhang
- Department of Hematology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.
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Tamoxifen induces apoptosis through cancerous inhibitor of protein phosphatase 2A-dependent phospho-Akt inactivation in estrogen receptor-negative human breast cancer cells. Breast Cancer Res 2014; 16:431. [PMID: 25228280 PMCID: PMC4303112 DOI: 10.1186/s13058-014-0431-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 08/21/2014] [Indexed: 11/11/2022] Open
Abstract
Introduction Tamoxifen, a selective estrogen receptor (ER) modulator, may affect cancer cell survival through mechanisms other than ER antagonism. In the present study, we tested the efficacy of tamoxifen in a panel of ER-negative breast cancer cell lines and examined the drug mechanism. Methods In total, five ER-negative breast cancer cell lines (HCC-1937, MDA-MB-231, MDA-MB-468, MDA-MB-453 and SK-BR-3) were used for in vitro studies. Cellular apoptosis was examined by flow cytometry and Western blot analysis. Signal transduction pathways in cells were assessed by Western blot analysis. The in vivo efficacy of tamoxifen was tested in xenograft nude mice. Results Tamoxifen induced significant apoptosis in MDA-MB-231, MDA-MB-468, MDA-MB-453 and SK-BR-3 cells, but not in HCC-1937 cells. Tamoxifen-induced apoptosis was associated with inhibition of cancerous inhibitor of protein phosphatase 2A (CIP2A) and phospho-Akt (p-Akt) in a dose-dependent manner. Ectopic expression of either CIP2A or Akt protected MDA-MB-231 cells from tamoxifen-induced apoptosis. In addition, tamoxifen increased protein phosphatase 2A (PP2A) activity, and tamoxifen-induced apoptosis was attenuated by the PP2A antagonist okadaic acid in the sensitive cell lines, but not in resistant HCC-1937 cells. Moreover, silencing CIP2A by small interfering RNA sensitized HCC-1937 cells to tamoxifen-induced apoptosis. Furthermore, tamoxifen regulated CIP2A protein expression by downregulating CIP2A mRNA. Importantly, tamoxifen inhibited the in vivo growth of MDA-MB-468 xenograft tumors in association with CIP2A downregulation, whereas tamoxifen had no significant effect on CIP2A expression and anti-tumor growth in HCC-1937 tumors. Conclusions Inhibition of CIP2A determines the effects of tamoxifen-induced apoptosis in ER-negative breast cancer cells. Our data suggest a novel “off-target“ mechanism of tamoxifen and suggest that CIP2A/PP2A/p-Akt signaling may be a feasible anti-cancer pathway. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0431-9) contains supplementary material, which is available to authorized users.
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CIP2A is overexpressed and involved in the pathogenesis of chronic myelocytic leukemia by interacting with breakpoint cluster region-Abelson leukemia virus. Med Oncol 2014; 31:112. [DOI: 10.1007/s12032-014-0112-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/30/2014] [Indexed: 01/26/2023]
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De P, Carlson J, Leyland-Jones B, Dey N. Oncogenic nexus of cancerous inhibitor of protein phosphatase 2A (CIP2A): an oncoprotein with many hands. Oncotarget 2014; 5:4581-602. [PMID: 25015035 PMCID: PMC4148086 DOI: 10.18632/oncotarget.2127] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/20/2014] [Indexed: 12/23/2022] Open
Abstract
Oncoprotein CIP2A a Cancerous Inhibitor of PP2A forms an "oncogenic nexus" by virtue of its control on PP2A and MYC stabilization in cancer cells. The expression and prognostic function of CIP2A in different solid tumors including colorectal carcinoma, head and neck cancers, gastric cancers, lung carcinoma, cholangiocarcinoma, esophageal cancers, pancreatic carcinoma, brain cancers, breast carcinoma, bladder cancers, ovarian carcinoma, renal cell carcinomas, tongue cancers, cervical carcinoma, prostate cancers, and oral carcinoma as well as a number of hematological malignancies are just beginning to emerge. Herein, we reviewed the recent progress in our understanding of (1) how an "oncogenic nexus" of CIP2A participates in the tumorigenic transformation of cells and (2) how we can prospect/view the clinical relevance of CIP2A in the context of cancer therapy. The review will try to understand the role of CIP2A (a) as a biomarker in cancers and evaluate the prognostic value of CIP2A in different cancers (b) as a therapeutic target in cancers and (c) in drug response and developing chemo-resistance in cancers.
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Affiliation(s)
- Pradip De
- Department of Molecular & Experimental Medicine, Avera Research Institute, Sioux Falls, SD
- Department of Internal Medicine, SSOM, University of South Dakota, Sioux Falls, SD
| | - Jennifer Carlson
- Department of Molecular & Experimental Medicine, Avera Research Institute, Sioux Falls, SD
| | - Brian Leyland-Jones
- Department of Molecular & Experimental Medicine, Avera Research Institute, Sioux Falls, SD
- Department of Internal Medicine, SSOM, University of South Dakota, Sioux Falls, SD
| | - Nandini Dey
- Department of Molecular & Experimental Medicine, Avera Research Institute, Sioux Falls, SD
- Department of Internal Medicine, SSOM, University of South Dakota, Sioux Falls, SD
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28
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Targeting c-MYC by antagonizing PP2A inhibitors in breast cancer. Proc Natl Acad Sci U S A 2014; 111:9157-62. [PMID: 24927563 DOI: 10.1073/pnas.1317630111] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transcription factor c-MYC is stabilized and activated by phosphorylation at serine 62 (S62) in breast cancer. Protein phosphatase 2A (PP2A) is a critical negative regulator of c-MYC through its ability to dephosphorylate S62. By inactivating c-MYC and other key signaling pathways, PP2A plays an important tumor suppressor function. Two endogenous inhibitors of PP2A, I2PP2A, Inhibitor-2 of PP2A (SET oncoprotein) and cancerous inhibitor of PP2A (CIP2A), inactivate PP2A and are overexpressed in several tumor types. Here we show that SET is overexpressed in about 50-60% and CIP2A in about 90% of breast cancers. Knockdown of SET or CIP2A reduces the tumorigenic potential of breast cancer cell lines both in vitro and in vivo. Treatment of breast cancer cells in vitro or in vivo with OP449, a novel SET antagonist, also decreases the tumorigenic potential of breast cancer cells and induces apoptosis. We show that this is, at least in part, due to decreased S62 phosphorylation of c-MYC and reduced c-MYC activity and target gene expression. Because of the ubiquitous expression and tumor suppressor activity of PP2A in cells, as well as the critical role of c-MYC in human cancer, we propose that activation of PP2A (here accomplished through antagonizing endogenous inhibitors) could be a novel antitumor strategy to posttranslationally target c-MYC in breast cancer.
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29
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Choi YA, Koo JS, Park JS, Park MY, Jeong AL, Oh KS, Yang Y. Estradiol enhances CIP2A expression by the activation of p70 S6 kinase. Endocr Relat Cancer 2014; 21:189-202. [PMID: 24280132 DOI: 10.1530/erc-13-0453] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cancerous inhibitor of PP2A (CIP2A) stimulates the proliferation of various cancer cells, and 17β-estradiol (E₂) enhances the proliferation of breast cancer cells. E₂ activates epidermal growth factor receptor (EGFR), stimulating the MEK1/2 and PI3K pathways, and CIP2A expression is increased by the MEK1/2-induced transcription factor ETS1. It is possible for E₂ to increase CIP2A expression. This study examined whether E₂ could increase CIP2A expression and whether CIP2A is highly expressed in estrogen receptor (ER)-positive breast cancer tissues. E₂ increased CIP2A expression at the translational level in a c-MYC-independent manner in MCF-7 cells. E₂-enhanced proliferation was impaired without CIP2A expression. E₂-stimulated EGFR activated the MAPK and PI3K pathways, which converged to activate p70 S6 kinase (S6K). Phosphorylation at all the three phosphorylation sites (S424/T421, T229, and T389) on S6K was required for the phosphorylation of eukaryotic initiation factor 4B (eIF4B), which was responsible for the increase in CIP2A translation. Furthermore, CIP2A expression was higher in ER-positive tissues than in ER-negative tissues. This is the first study, to our knowledge, to demonstrate that CIP2A is a key factor in E₂-enhanced proliferation and that estrogen regulates CIP2A expression by non-genomic action through EGFR.
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Affiliation(s)
- Yeon A Choi
- Department of Life Science, Research Center for Women's Disease, Sookmyung Women's University, Seoul 140-742, Republic of Korea Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea
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Baldacchino S, Saliba C, Petroni V, Fenech AG, Borg N, Grech G. Deregulation of the phosphatase, PP2A is a common event in breast cancer, predicting sensitivity to FTY720. EPMA J 2014; 5:3. [PMID: 24460909 PMCID: PMC3913630 DOI: 10.1186/1878-5085-5-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 01/09/2014] [Indexed: 01/01/2023]
Abstract
Background The most commonly used biomarkers to predict the response of breast cancer patients to therapy are the oestrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2). Patients positive for these biomarkers are eligible for specific therapies such as endocrine treatment in the event of ER and PgR positivity, and the monoclonal antibody, trastuzumab, in the case of HER2-positive patients. Patients who are negative for these three biomarkers, the so-called triple negatives, however, derive little benefit from such therapies and are associated with a worse prognosis. Deregulation of the protein serine/threonine phosphatase type 2A (PP2A) and its regulatory subunits is a common event in breast cancer, providing a possible target for therapy. Methods The data portal, cBioPortal for Cancer Genomics was used to investigate the incidence of conditions that are associated with low phosphatase activity. Four (4) adherent human breast cancer cell lines, MDA-MB-468, MDA-MB-436, Hs578T and BT-20 were cultured to assess their viability when exposed to various dosages of rapamycin or FTY720. In addition, RNA was extracted and cDNA was synthesised to amplify the coding sequence of PPP2CA. Amplification was followed by high-resolution melting to identify variations. Results and conclusion The sequence of PPP2CA was found to be conserved across a diverse panel of solid tumour and haematological cell lines, suggesting that low expression of PPP2CA and differential binding of inhibitory PPP2CA regulators are the main mechanisms of PP2A deregulation. Interestingly, the cBioPortal for Cancer Genomics shows that PP2A is deregulated in 59.6% of basal breast tumours. Viability assays performed to determine the sensitivity of a panel of breast cancer cell lines to FTY720, a PP2A activator, indicated that cell lines associated with ER loss are sensitive to lower doses of FTY720. The subset of patients with suppressed PP2A activity is potentially eligible for treatment using therapies which target the PI3K/AKT/mTOR pathway, such as phosphatase activators.
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Affiliation(s)
- Shawn Baldacchino
- Department of Pathology, Medical School, University of Malta, Msida MSD2090, Malta
| | - Christian Saliba
- Department of Pathology, Medical School, University of Malta, Msida MSD2090, Malta
| | - Vanessa Petroni
- Department of Clinical Pharmacology and Therapeutics, University of Malta, Msida MSD2090, Malta
| | - Anthony G Fenech
- Department of Clinical Pharmacology and Therapeutics, University of Malta, Msida MSD2090, Malta
| | - Nigel Borg
- Department of Pathology, Medical School, University of Malta, Msida MSD2090, Malta
| | - Godfrey Grech
- Department of Pathology, Medical School, University of Malta, Msida MSD2090, Malta
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Liu X, Chai Y, Li J, Ren P, Liu M, Dai L, Qian W, Li W, Zhang JY. Autoantibody response to a novel tumor-associated antigen p90/CIP2A in breast cancer immunodiagnosis. Tumour Biol 2014; 35:2661-7. [PMID: 24399648 DOI: 10.1007/s13277-013-1350-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 10/22/2013] [Indexed: 12/19/2022] Open
Abstract
There is an urgent need to identify relevant tumor markers showing high sensitivity and specificity for early immunodiagnosis of breast cancer. Autoantibodies directed against tumor-associated antigens (TAAs) have been shown to be relevant tumor markers. The purpose of this study was to evaluate whether autoantibodies to a tumor-associated antigen p90/CIP2A can be used as diagnostic markers in breast cancer. In this study, autoantibody responses to p90/CIP2A were evaluated by enzyme-linked immunosorbent assay (ELISA), western blotting, and indirect immunofluorescence assay in sera from patients with breast cancer and normal human individuals. The results have demonstrated that p90/CIP2A can induce a relatively higher frequency of autoantibody response in breast cancer (19.1%) compared to the sera of normal individuals (2.3%). The frequency of p90/CIP2A expression in breast cancer tissues was significantly higher than that in adjacent normal tissues (P < 0.01). Our preliminary results suggest that autoantibodies against p90/CIP2A may be a useful serum biomarker for early stage breast cancer screening and diagnosis.
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Affiliation(s)
- Xinxin Liu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, China
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Shi F, Ding Y, Ju S, Wu X, Cao S. Expression and prognostic significance of CIP2A in cutaneous malignant melanoma. Biomarkers 2013; 19:70-6. [PMID: 24369732 DOI: 10.3109/1354750x.2013.871752] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE We investigated the expression and clinical significance of Cancerous inhibitor of protein phosphatase 2A (CIP2A) in Cutaneous malignant melanoma (CMM). METHODS CIP2A expression was analyzed by immunohistochemistry and western blot. We tested the invasion and migration capability of A375 cells with Matrigel invasion assay, Scratch migration assay and Matrigel migration assay after down-regulating CIP2A expression using siRNA. RESULTS CIP2A immunostaining level was correlated with Breslow thickness, Clark's Level and lymphovascular invasion. High-CIP2A expression implied poor survival for patients. Downregulation of CIP2A attenuated metastasis of CMM cells. CONCLUSIONS CIP2A may serve as a novel marker to predict the prognosis for CMM patients.
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Affiliation(s)
- Feng Shi
- Department of Dermatology and Venereology, Nantong University , Nantong, Jiangsu , China
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Jeong AL, Lee S, Park JS, Han S, Jang CY, Lim JS, Lee MS, Yang Y. Cancerous inhibitor of protein phosphatase 2A (CIP2A) protein is involved in centrosome separation through the regulation of NIMA (never in mitosis gene A)-related kinase 2 (NEK2) protein activity. J Biol Chem 2013; 289:28-40. [PMID: 24214971 DOI: 10.1074/jbc.m113.507954] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is overexpressed in most human cancers and has been described as being involved in the progression of several human malignancies via the inhibition of protein phosphatase 2A (PP2A) activity toward c-Myc. However, with the exception of this role, the cellular function of CIP2A remains poorly understood. On the basis of yeast two-hybrid and coimmunoprecipitation assays, we demonstrate here that NIMA (never in mitosis gene A)-related kinase 2 (NEK2) is a binding partner for CIP2A. CIP2A exhibited dynamic changes in distribution, including the cytoplasm and centrosome, depending on the cell cycle stage. When CIP2A was depleted, centrosome separation and the mitotic spindle dynamics were impaired, resulting in the activation of spindle assembly checkpoint signaling and, ultimately, extension of the cell division time. Our data imply that CIP2A strongly interacts with NEK2 during G2/M phase, thereby enhancing NEK2 kinase activity to facilitate centrosome separation in a PP1- and PP2A-independent manner. In conclusion, CIP2A is involved in cell cycle progression through centrosome separation and mitotic spindle dynamics.
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Affiliation(s)
- Ae Lee Jeong
- From the Research Center for Women's Disease, Department of Life Systems and
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Abstract
PP2A is a family of mammalian serine/threonine phosphatases that is involved in the control of many cellular functions including protein synthesis, cellular signaling, cell cycle determination, apoptosis, metabolism, and stress responses through the negative regulation of signaling pathways initiated by protein kinases. Rapid progress is being made in the understanding of PP2A complex and its functions. Emerging studies have correlated changes in PP2A with human diseases, especially cancer. PP2A is comprised of 3 subunits: a catalytic subunit, a scaffolding subunit, and a regulatory subunit. The alternations of the subunits have been shown to be in association with many human malignancies. Therapeutic agents targeting PP2A inhibitors or activating PP2A directly have shed light on the therapy of cancers. This review focuses on PP2A structure, cancer-associated mutations, and the targeting of PP2A-related molecules to restore or reactivate PP2A in anticancer therapy, especially in digestive system cancer therapy.
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Khanna A, Pimanda JE, Westermarck J. Cancerous Inhibitor of Protein Phosphatase 2A, an Emerging Human Oncoprotein and a Potential Cancer Therapy Target. Cancer Res 2013; 73:6548-53. [DOI: 10.1158/0008-5472.can-13-1994] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Protein phosphatase 2A (PP2A), one of the main serine-threonine phosphatases in mammalian cells, maintains cell homoeostasis by counteracting most of the kinase-driven intracellular signalling pathways. Unrestrained activation of oncogenic kinases together with inhibition of tumour suppressors is often required for development of cancer. PP2A has been shown to be genetically altered or functionally inactivated in many solid cancers and leukaemias, and is therefore a tumour suppressor. For example, the phosphatase activity of PP2A is suppressed in chronic myeloid leukaemia and other malignancies characterised by aberrant activity of oncogenic kinases. Preclinical studies show that pharmacological restoration of PP2A tumour-suppressor activity by PP2A-activating drugs (eg, FTY720) effectively antagonises cancer development and progression. Here, we discuss PP2A as a druggable tumour suppressor in view of the possible introduction of PP2A-activating drugs into anticancer therapeutic protocols.
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Affiliation(s)
- Danilo Perrotti
- Human Cancer Genetics Program, Department of Molecular Virology, Immunology, and Medical Genetics, and Comprehensive Cancer Center, Ohio State University, Columbus, OH 43210-2207, USA.
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Cancerous inhibitor of protein phosphatase 2A mediates bortezomib-induced autophagy in hepatocellular carcinoma independent of proteasome. PLoS One 2013; 8:e55705. [PMID: 23383345 PMCID: PMC3562236 DOI: 10.1371/journal.pone.0055705] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 12/28/2012] [Indexed: 12/25/2022] Open
Abstract
Previously, we reported that cancerous inhibitor of protein phosphatase 2A (CIP2A) mediates the apoptotic effect of bortezomib in hepatocellular carcinoma (HCC). Here, we report a proteasome-independent mechanism by which bortezomib induces autophagy in HCC. Our data indicate that bortezomib activated autophagy in a dose- and time- dependent manner in HCC cell lines including Huh-7, Sk-Hep1, and Hep3B. Bortezomib downregulated CIP2A, phospho-Akt (P-Akt) and phospho-4EBP1 (P-4EBP1) in a dose- and time-dependent manner in all tested HCC cells. Ectopic expression of CIP2A abolished the effect of bortezomib on autophagy. Co-treatment of bortezomib and calyculin A, a PP2A inhibitor, reduced the effect of bortezomib on P-Akt, P-4EBP1, and autophagy. Increased phosphorylation of either Akt or 4EBP1 by ectopic overexpression protected cells from bortezomib-induced autophagy. Furthermore, we examined the effect of ΔBtz, a bortezomib derivative that closely resembles bortezomib structurally but has no proteasome activity, in HCC. Interestingly, ΔBtz demonstrated similar effects to bortezomib on autophagy, CIP2A, P-Akt and P-4EBP1, suggesting that the effect of bortezomib on autophagy is independent of proteasome inhibition. Moreover, our in vivo data showed that both bortezomib and ΔBtz inhibited tumor growth, downregulated CIP2A, P-Akt and induced autophagy in Huh-7 tumors. In conclusion, bortezomib induces autophagy in HCC through a CIP2A-PP2A-Akt-4EBP1 pathway.
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Xue Y, Wu G, Wang X, Zou X, Zhang G, Xiao R, Yuan Y, Long D, Yang J, Wu Y, Xu H, Liu F, Liu M. CIP2A is a predictor of survival and a novel therapeutic target in bladder urothelial cell carcinoma. Med Oncol 2012; 30:406. [PMID: 23275123 DOI: 10.1007/s12032-012-0406-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 10/05/2012] [Indexed: 11/28/2022]
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified human oncoprotein that stabilizes the c-MYC protein. Herein, we aimed to investigate its expression pattern, clinical significance, and biological function in urothelial cell carcinoma (UCC) of the bladder. CIP2A expression was examined in 20 fresh bladder UCC tissues and paired adjacent normal bladder tissues by RT-PCR and Western blot. Immunohistochemistry for CIP2A was performed on additional 117 bladder UCC tissues. The clinical significance of CIP2A expression was analyzed. CIP2A downregulation was performed in bladder UCC cell line T24 with high abundance of CIP2A, and the effects of CIP2A silencing on cell proliferation, migration, invasion in vitro, and tumor growth in vivo were evaluated. We found that CIP2A expression was upregulated in bladder UCC tissues relative to adjacent normal bladder tissues. Clinicopathological analysis showed that CIP2A expression was significantly associated with tumor stage (P = 0.004), histological grade (P = 0.007), and lymph node status (P = 0.001). The Kaplan-Meier survival curves revealed that CIP2A expression was associated with poor prognosis in bladder UCC patients (log-rank value = 14.704, P < 0.001). CIP2A expression was an independent prognostic marker of overall patient survival in a multivariate analysis (P = 0.015). Knockdown of the CIP2A expression reduced cell proliferation, anchorage-independent growth, migration, invasion, and tumor growth in xenograft model mice. Our findings suggest that CIP2A is an independent predictor of poor prognosis of bladder UCC patients, and inhibition of its expression might be of therapeutic significance.
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Affiliation(s)
- Yijun Xue
- Department of Urology, First Affiliated Hospital of Gannan Medical University, No. 23, Qing Nian Road, Ganzhou 341000, China
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Abstract
Erlotinib is a small-molecular inhibitor of epidermal growth factor receptor (EGFR). Here, we identify that cancerous inhibitor of protein phosphatase 2A (CIP2A) is a major determinant mediating erlotinib-induced apoptosis in hepatocellular carcinoma (HCC). Erlotinib showed differential effects on apoptosis in 4 human HCC cell lines. Erlotinib induced significant apoptosis in Hep3B and PLC5 cell lines; however, Huh-7 and HA59T cell lines showed resistance to erlotinib-induced apoptosis at all tested doses. Down-regulation of CIP2A, a cellular inhibitor of protein phosphatase 2A (PP2A), mediated the apoptotic effect of erlotinib in HCC. Erlotinib inhibited CIP2A in a dose- and time-dependent manner in all sensitive HCC cells whereas no alterations in CIP2A were found in resistant cells. Overexpression of CIP2A upregulated phospho-Akt and protected Hep3B cells from erlotinib-induced apoptosis. In addition, silencing CIP2A by siRNA restored the effects of erlotinib in Huh-7 cells. Moreover, adding okadaic acid, a PP2A inhibitor, abolished the effects of erlotinib on apoptosis in Hep3B cells; and forskolin, a PP2A agonist enhanced the effect of erlotinib in resistant HA59T cells. Combining Akt inhibitor MK-2206 with erlotinib restored the sensitivity of HA59T cells to erlotinib. Furthermore, in vivo xenograft data showed that erlotinib inhibited the growth of PLC5 tumor but had no effect on Huh-7 tumor. Erlotinib downregulated CIP2A and upregulated PP2A activity in PLC5 tumors, but not in Huh-7 tumors. In conclusion, inhibition of CIP2A determines the effects of erlotinib on apoptosis in HCC. CIP2A may be useful as a therapeutic biomarker for predicting clinical response to erlotinib in HCC treatment.
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Pallai R, Bhaskar A, Sodi V, Rice LM. Ets1 and Elk1 transcription factors regulate cancerous inhibitor of protein phosphatase 2A expression in cervical and endometrial carcinoma cells. Transcription 2012; 3:323-35. [PMID: 23117818 DOI: 10.4161/trns.22518] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) has been identified as a proto-oncogene that is overexpressed in various types of human cancers. CIP2A acts by inhibiting protein phosphatase 2A-dependent destabilization of c-Myc, resulting in increased cell proliferation. Here, we have characterized the proximal promoter region of the human CIP2A gene in cervical, endometrial and liver carcinoma cells. The 5' flanking minimal proximal promoter of the CIP2A gene consists of putative binding sites for Ets1 and Elk1 in forward and reverse orientations. Here, we show that Ets1 and Elk1 binding is essential for CIP2A basal expression in several urogenital cancer cell lines. Interestingly, both Ets1 and Elk1 are required together for CIP2A expression, as siRNA knockdown of Ets1 and Elk1 together decreased CIP2A gene transcription, whereas knockdown of Ets1 or Elk1 alone had no effect. Moreover, ectopic expression of Ets1 and Elk1 together increased CIP2A expression. To gain physiological significance of the Ets1 and Elk1 regulation we observed, a panel of matched human cervical carcinoma samples was analyzed for the expression of CIP2A and Ets1 and/or Elk1. We found a direct correlation between the levels of CIP2A and the levels of Ets1 and Elk1. Our results suggest that the binding of Ets1 and Elk1 together to the proximal CIP2A promoter is absolutely required for CIP2A expression in cervical, endometrial and liver carcinoma cell lines. Thus, different factors regulate CIP2A expression in a cell-type specific manner. As previous work has shown a requirement for only Ets1 in prostate and gastric carcinomas, our results now indicate that CIP2A regulation is more complex than previously determined.
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Affiliation(s)
- Rajash Pallai
- Department of Cancer Signaling and Cell Cycle, Venenum Biodesign, L.L.C, Hamilton, NJ, USA
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Liu CY, Shiau CW, Kuo HY, Huang HP, Chen MH, Tzeng CH, Chen KF. Cancerous inhibitor of protein phosphatase 2A determines bortezomib-induced apoptosis in leukemia cells. Haematologica 2012; 98:729-38. [PMID: 22983581 DOI: 10.3324/haematol.2011.050187] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The multiple cellular targets affected by proteasome inhibition implicate a potential role for bortezomib, a first-in-class proteasome inhibitor, in enhancing antitumor activities in hematologic malignancies. Here, we examined the antitumor activity and drug targets of bortezomib in leukemia cells. Human leukemia cell lines were used for in vitro studies. Drug efficacy was evaluated by apoptosis assays and associated molecular events assessed by Western Blot. Gene silencing was performed by small interference RNA. Drug was tested in vivo in xenograft models of human leukemia cell lines and in primary leukemia cells. Clinical samples were assessed by immunohistochemical staining. Bortezomib differentially induced apoptosis in leukemia cells that was independent of its proteasome inhibition. Cancerous inhibitor of protein phosphatase 2A, a cellular inhibitor of protein phosphatase 2A, mediated the apoptotic effect of bortezomib. Bortezomib increased protein phosphatase 2A activity in sensitive leukemia cells (HL-60 and KG-1), but not in resistant cells (MOLT-3 and K562). Bortezomib's downregulation of cancerous inhibitor of protein phosphatase 2A and phospho-Akt correlated with its drug sensitivity. Furthermore, cancerous inhibitor of protein phosphatase 2A negatively regulated protein phosphatase 2A activity. Ectopic expression of CIP2A up-regulated phospho-Akt and protected HL-60 cells from bortezomib-induced apoptosis, whereas silencing CIP2A overcame the resistance to bortezomib-induced apoptosis in MOLT3 and K562 cells. Importantly, bortezomib exerted in vivo antitumor activity in HL-60 xenografted tumors and induced cell death in some primary leukemic cells. Cancerous inhibitor of protein phosphatase 2A was expressed in leukemic blasts from bone marrow samples. Cancerous inhibitor of protein phosphatase 2A plays a major role in mediating bortezomib-induced apoptosis in leukemia cells.
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Affiliation(s)
- Chun-Yu Liu
- Institute of Biopharmaceutical Sciences, National Yang-Ming Universit, Taipei, Taiwan
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Chen KF, Pao KC, Su JC, Chou YC, Liu CY, Chen HJ, Huang JW, Kim I, Shiau CW. Development of erlotinib derivatives as CIP2A-ablating agents independent of EGFR activity. Bioorg Med Chem 2012; 20:6144-53. [PMID: 22980218 DOI: 10.1016/j.bmc.2012.08.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/08/2012] [Accepted: 08/09/2012] [Indexed: 10/28/2022]
Abstract
Cancerous inhibitor of PP2A (CIP2A) is a novel human oncoprotein that inhibits PP2A, contributing to tumor aggressiveness in various cancers. Several studies have shown that downregulation of CIP2A by small molecules reduces PP2A-dependent phosphorylation of Akt and induces cell death. Here, a series of mono- and di-substituted quinazoline and pyrimidine derivatives based on the skeleton of erlotinib (an EGFR inhibitor) were synthesized and their bioactivities against hepatocellular carcinoma were evaluated. The di-substituted quinazoline and pyrimidine derivatives were more potent inhibitors of cancer-cell proliferation than the mono-substituted derivatives. In particular, compound 1 with chloride at position 2 of quinazoline was as potent as erlotinib in inducing cell death but no inhibition for EGFR activity. Further assays confirmed a correlation between cell death, and CIP2A and Akt inhibition by these derivatives. Among all the derivatives, compounds 19 and 22 showed the most potent antiproliferative activities and the strongest inhibition of CIP2A and p-Akt expression.
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Affiliation(s)
- Kuen-Feng Chen
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan, ROC
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Lin YC, Chen KC, Chen CC, Cheng AL, Chen KF. CIP2A-mediated Akt activation plays a role in bortezomib-induced apoptosis in head and neck squamous cell carcinoma cells. Oral Oncol 2012; 48:585-93. [DOI: 10.1016/j.oraloncology.2012.01.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 01/22/2012] [Accepted: 01/25/2012] [Indexed: 12/27/2022]
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Huang P, Qiu J, You J, Hong J, Li B, Zhou K, Chen G, Yuan Y, Zou R. Expression and prognostic significance of CIP2A mRNA in hepatocellular carcinoma and nontumoral liver tissues. Biomarkers 2012; 17:422-9. [PMID: 22537152 DOI: 10.3109/1354750x.2012.680608] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE This study was undertaken to determine the role of cancerous inhibitor of protein phosphatase 2A (CIP2A) in predicting prognosis of hepatocellular carcinoma (HCC). METHODS CIP2A mRNA level of 136 pairs of tumor and nontumoral liver tissues of HCC patients after hepatectomy were investigated by quantitative real-time reverse transcription polymerase chain reaction. RESULTS Intratumoral CIP2A mRNA was not associated with patients' prognosis. However, nontumoral CIP2A mRNA, which was correlated with lack of tumor encapsulation, poor tumor differentiation, intrahepatic metastasis, and high tumor-node-metastasis stage was an independent risk factor for overall survival and recurrence-free survival. CONCLUSIONS Nontumoral CIP2A mRNA expression might serve as a novel biomarker for HCC patients undergoing resection.
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Affiliation(s)
- Pinzhu Huang
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
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Tseng LM, Liu CY, Chang KC, Chu PY, Shiau CW, Chen KF. CIP2A is a target of bortezomib in human triple negative breast cancer cells. Breast Cancer Res 2012; 14:R68. [PMID: 22537901 PMCID: PMC3446403 DOI: 10.1186/bcr3175] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 04/16/2012] [Accepted: 04/26/2012] [Indexed: 11/10/2022] Open
Abstract
Introduction Triple negative breast cancer (TNBC) is very aggressive and currently has no specific therapeutic targets, such as hormone receptors or human epidermal growth factor receptor type 2 (HER2); therefore, prognosis is poor. Bortezomib, a proteasome inhibitor, may exert efficacy in TNBC through its multiple cellular effects. Here, we tested the efficacy of bortezomib and examined the drug mechanism in breast cancer cells. Methods Five breast cancer cell lines: TNBC HCC-1937, MDA-MB-231, and MDA-MB-468; HER2-overexpressing MDA-MB-453; and estrogen receptor positive MCF-7 were used for in vitro studies. Apoptosis was examined by both flow cytometry and Western Blot. Signal transduction pathways in cells were assessed by Western Blot. Gene silencing was done by small interfering RNA (siRNA). In vivo efficacy of bortezomib was tested in nude mice with breast cancer xenografts. Immunohistochemical study was performed on tumor tissues from patients with TNBC. Results Bortezomib induced significant apoptosis, which was independent of its proteasome inhibition, in the three TNBC cell lines, but not in MDA-MB-453 or MCF-7 cells. Furthermore, cancerous inhibitor of protein phosphatase 2A (CIP2A), a cellular inhibitor of protein phosphatase 2A (PP2A), mediated the apoptotic effect of bortezomib. We showed that bortezomib inhibited CIP2A in association with p-Akt downregulation in a dose- and time-dependent manner in all sensitive TNBC cells, whereas no alterations in CIP2A expression and p-Akt were noted in bortezomib-resistant cells. Overexpression of CIP2A upregulated p-Akt and protected MDA-MB-231 and MDA-MB-468 cells from bortezomib-induced apoptosis, whereas silencing CIP2A by siRNA overcame the resistance to bortezomib-induced apoptosis in MCF-7 cells. In addition, bortezomib downregulated CIP2A mRNA but did not affect the degradation of CIP2A protein. Furthermore, bortezomib exerted in vivo antitumor activity in HCC-1937 xenografted tumors, but not in MCF-7 tumors. Bortezomib downregulated CIP2A expression in the HCC-1937 tumors but not in the MCF-7 tumors. Importantly, CIP2A expression is readily detectable in tumor samples from TNBC patients. Conclusions CIP2A is a major determinant mediating bortezomib-induced apoptosis in TNBC cells. CIP2A may thus be a potential therapeutic target in TNBC.
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Affiliation(s)
- Ling-Ming Tseng
- Department of Surgery, Taipei Veterans General Hospital, No. 201 Sec. 2 Shih-Pai Road, Taipei 112, Taiwan
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Ventelä S, Côme C, Mäkelä JA, Hobbs RM, Mannermaa L, Kallajoki M, Chan EK, Pandolfi PP, Toppari J, Westermarck J. CIP2A promotes proliferation of spermatogonial progenitor cells and spermatogenesis in mice. PLoS One 2012; 7:e33209. [PMID: 22461891 PMCID: PMC3312892 DOI: 10.1371/journal.pone.0033209] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 02/13/2012] [Indexed: 01/05/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a critical regulator of protein serine/threonine phosphorylation. However, the physiological and developmental roles of different PP2A complexes are very poorly understood. Here, we show that a newly characterized PP2A inhibitory protein CIP2A is co-expressed with ki-67 and with self-renewal protein PLZF in the spermatogonial progenitor cell (SPC) population in the testis. CIP2A and PLZF expression was shown also to correlate Ki-67 expression in human testicular spermatogonia. Functionally, CIP2A mutant mouse testes exhibited smaller number of PLZF-positive SPCs and reduced sperm counts. Moreover, seminiferous tubuli cells isolated from CIP2A mutant mice showed reduced expression of Plzf and other renewal genes Oct-4 and Nanog at mRNA level. However, PLZF-deficient testes did not show altered CIP2A expression. Importantly, spermatogonia-specific restoration of CIP2A expression rescued PLZF expression and sperm production defects observed in CIP2A mutant mice. Taken together, these results reveal first physiological function for an emerging human oncoprotein CIP2A, and provide insights into maintenance of PLZF-positive progenitors. Moreover, demonstration that CIP2A expression can be systematically inhibited without severe consequences to normal mouse development and viability may have clinical relevance regarding targeting of oncogenic CIP2A for future cancer therapies.
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Affiliation(s)
- Sami Ventelä
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Physiology, University of Turku, Turku, Finland
- Department of Otorhinolaryngology, Turku University Hospital, Turku, Finland
| | - Christophe Côme
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Juho-Antti Mäkelä
- Department of Physiology, University of Turku, Turku, Finland
- Turku Graduate School of Biomedical Sciences, University of Turku, Turku, Finland
| | - Robin M. Hobbs
- Cancer Genetics Program, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Leni Mannermaa
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | | | - Edward K. Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
| | - Pier Paolo Pandolfi
- Cancer Genetics Program, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jorma Toppari
- Department of Physiology, University of Turku, Turku, Finland
- Department of Pediatrics, Turku University Hospital, Turku, Finland
| | - Jukka Westermarck
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Pathology, University of Turku, Turku, Finland
- * E-mail:
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Böckelman C, Koskensalo S, Hagström J, Lundin M, Ristimäki A, Haglund C. CIP2A overexpression is associated with c-Myc expression in colorectal cancer. Cancer Biol Ther 2012; 13:289-95. [PMID: 22310977 DOI: 10.4161/cbt.18922] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND To improve the prognostic evaluation of colorectal cancer requires new molecular markers. Cancerous inhibitor of protein phosphatase 2A (CIP2A) serves as an oncoprotein by targeting PP 2A-mediated inhibition of c-Myc. A prognostic role for CIP2A has been demonstrated in gastric, lung and tongue cancers. RESULTS CIP2A was overexpressed in 661 (87.9%) specimens. CIP2A overexpression was associated with tumor differentiation grade (p = 0.014), p53 immunopositivity (p = 0.042), EGFR immunopositivity (p = 0.007) and c-Myc nuclear immunopositivity (p = 0.018). In survival analysis, CIP2A failed to show any prognostic significance (p = 0.270, log-rank test). METHODS 863 consecutive colorectal cancer patients treated at Helsinki University Central Hospital in 1983–2001 were collected with 752 scored successfully for CIP2A immunohistochemical expression from tumor tissue microarrays. Associations with clinicopathologic variables and molecular markers were explored by the chi-square test, and the Kaplan-Meier method served for survival analysis. CONCLUSIONS Overexpression of CIP2A in colorectal cancer patients may be an important step in colorectal carcinogenesis. Based on our findings, CIP2A shows no association with patient prognosis in colorectal cancer, but is associated with nuclear c-Myc.
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Affiliation(s)
- Camilla Böckelman
- Genome-Scale Biology Research Program, Biomedicum Helsinki, Helsinki, Finland
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Expression of CIP2A in renal cell carcinomas correlates with tumour invasion, metastasis and patients' survival. Br J Cancer 2011; 105:1905-11. [PMID: 22075943 PMCID: PMC3251889 DOI: 10.1038/bjc.2011.492] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Background: Cancerous inhibitor of protein phosphatase 2A (CIP2A) drives cellular transformation. The objective of this study was to detect the potential effects of CIP2A in renal cell carcinomas (RCCs). Methods: A total of 107 RCC patients were involved in the study. Cancerous inhibitor of protein phosphatase 2A expression was investigated by real-time PCR and immunohistochemistry. In vitro, we examined the expression of CIP2A and c-Myc and tested the migration and invasion capability of A498 and KRC/Y cells with scratch migration assay and Matrigel invasion assay after down-regulating CIP2A expression using siRNA. Results: Cancerous inhibitor of protein phosphatase 2A was over-expressed in RCC tissues. Clear cell RCC showed an even higher-CIP2A expression level than papillary or chromophobe RCC did. The CIP2A immunostaining level was positively correlated with primary tumour stage, lymph node metastasis, distant metastasis, TNM stage and histological grade (all P<0.05). High-CIP2A expression implied poor survival for patients (P<0.05). Cancerous inhibitor of protein phosphatase 2A depletion by siRNA down-regulated c-Myc expression and attenuated the migration and invasion of RCC cells. Conclusion: Higher-CIP2A expression positively correlates with the aggressive phenotype of RCCs, and predicts poor prognosis for patients. Cancerous inhibitor of protein phosphatase 2A may be a novel target for prevention and treatment of RCC metastasis and recurrence.
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Overexpression and small molecule-triggered downregulation of CIP2A in lung cancer. PLoS One 2011; 6:e20159. [PMID: 21655278 PMCID: PMC3105001 DOI: 10.1371/journal.pone.0020159] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 04/12/2011] [Indexed: 11/19/2022] Open
Abstract
Background Lung cancer is the leading cause of cancer deaths worldwide, with a five-year overall survival rate of only 15%. Cancerous inhibitor of PP2A (CIP2A) is a human oncoprotein inhibiting PP2A in many human malignancies. However, whether CIP2A can be a new drug target for lung cancer is largely unclear. Methodology/Principal Findings Normal and malignant lung tissues were derived from 60 lung cancer patients from southern China. RT-PCR, Western blotting and immunohistochemistry were used to evaluate the expression of CIP2A. We found that among the 60 patients, CIP2A was undetectable or very low in paratumor normal tissues, but was dramatically elevated in tumor samples in 38 (63.3%) patients. CIP2A overexpression was associated with cigarette smoking. Silencing CIP2A by siRNA inhibited the proliferation and clonogenic activity of lung cancer cells. Intriguingly, we found a natural compound, rabdocoetsin B which is extracted from a Traditional Chinese Medicinal herb Rabdosia coetsa, could induce down-regulation of CIP2A and inactivation of Akt pathway, and inhibit proliferation and induce apoptosis in a variety of lung cancer cells. Conclusions/Significance Our findings strongly indicate that CIP2A could be an effective target for lung cancer drug development, and the therapeutic potentials of CIP2A-targeting agents warrant further investigation.
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Cancerous inhibitor of PP2A (CIP2A) at diagnosis of chronic myeloid leukemia is a critical determinant of disease progression. Blood 2011; 117:6660-8. [PMID: 21490338 DOI: 10.1182/blood-2010-08-304477] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Prospective identification of patients whose chronic myeloid leukemia (CML) will progress to blast crisis is currently not possible. PP2A is a phosphatase and tumor suppressor that regulates cell proliferation, differentiation, and survival. Cancerous inhibitor of PP2A (CIP2A) is a recently described inhibitor of PP2A in breast and gastric cancer. The aim of this study was to investigate whether CIP2A played a role in CML and whether PP2A or its inhibitor proteins CIP2A or SET could predict clinical outcome. At the time of diagnosis of CML, patients who will later progress to blast crisis have significantly higher levels of CIP2A protein (P < .0001) than patients who do not progress, suggesting that PP2A is functionally inactive. We show that the potential mechanism for disease progression is via altered phosphorylation of the oncogene c-Myc. Knockdown of CIP2A results in increased PP2A activity, decreased c-Myc levels, and a decrease in BCR-ABL1 tyrosine kinase activity. We demonstrate that CIP2A levels at diagnosis can consistently predict patients who will progress to blast crisis. The data show that CIP2A is biologically and clinically important in CML and may be a novel therapeutic target.
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