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Hassan M, Yasir M, Shahzadi S, Chun W, Kloczkowski A. Molecular Role of Protein Phosphatases in Alzheimer's and Other Neurodegenerative Diseases. Biomedicines 2024; 12:1097. [PMID: 38791058 PMCID: PMC11117500 DOI: 10.3390/biomedicines12051097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/02/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Alzheimer's disease (AD) is distinguished by the gradual loss of cognitive function, which is associated with neuronal loss and death. Accumulating evidence supports that protein phosphatases (PPs; PP1, PP2A, PP2B, PP4, PP5, PP6, and PP7) are directly linked with amyloid beta (Aβ) as well as the formation of the neurofibrillary tangles (NFTs) causing AD. Published data reported lower PP1 and PP2A activity in both gray and white matters in AD brains than in the controls, which clearly shows that dysfunctional phosphatases play a significant role in AD. Moreover, PP2A is also a major causing factor of AD through the deregulation of the tau protein. Here, we review recent advances on the role of protein phosphatases in the pathology of AD and other neurodegenerative diseases. A better understanding of this problem may lead to the development of phosphatase-targeted therapies for neurodegenerative disorders in the near future.
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Affiliation(s)
- Mubashir Hassan
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA;
| | - Muhammad Yasir
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea; (M.Y.); (W.C.)
| | - Saba Shahzadi
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA;
| | - Wanjoo Chun
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea; (M.Y.); (W.C.)
| | - Andrzej Kloczkowski
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA;
- Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH 43210, USA
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Zhao T, Ding T, Sun Z, Shao X, Li S, Lu H, Yuan JH, Guo Z. SPHK1/S1P/S1PR pathway promotes the progression of peritoneal fibrosis by mesothelial-mesenchymal transition. FASEB J 2024; 38:e23417. [PMID: 38226856 DOI: 10.1096/fj.202301323r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/23/2023] [Accepted: 12/27/2023] [Indexed: 01/17/2024]
Abstract
Long-term exposure to non-physiologically compatible dialysate inevitably leads to peritoneal fibrosis (PF) in patients undergoing peritoneal dialysis (PD), and there is no effective prevention or treatment for PF. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid produced after catalysis by sphingosine kinase (SPHK) 1/2 and activates signals through the S1P receptor (S1PR) via autocrine or paracrine. However, the role of SPHK1/S1P/S1PR signaling has never been elucidated in PF. In our research, we investigated S1P levels in peritoneal effluents and demonstrated the role of SPHK1/S1P/S1PR pathway in peritoneal fibrosis. It was found that S1P levels in peritoneal effluents were positively correlated with D/P Cr (r = 0.724, p < .001) and negatively correlated with 4 h ultrafiltration volume (r = -0.457, p < .001). S1PR1 and S1PR3 on peritoneal cells were increased after high glucose exposure in vivo and in vitro. Fingolimod was applied to suppress S1P/S1PR pathway. Fingolimod restored mouse peritoneal function by reducing interstitial hyperplasia, maintaining ultrafiltration volume, reducing peritoneal transport solute rate, and mitigating the protein expression changes of fibronectin, vimentin, α-SMA, and E-cadherin induced by PD and S1P. Fingolimod preserved the morphology of the human peritoneal mesothelial cells, MeT-5A, and moderated the mesothelial-mesenchymal transition (MMT) process. We further delineated that SPHK1 was elevated in peritoneal cells after high glucose exposure and suppression of SPHK1 in MeT-5A cells reduced S1P release. Overexpression of SPHK1 in MeT-5A cells increased S1P levels in the supernatant and fostered the MMT process. PF-543 treatment, targeting SPHK1, alleviated deterioration of mouse peritoneal function. In conclusion, S1P levels in peritoneal effluent were correlated with the deterioration of peritoneal function. SPHK1/S1P/S1PR pathway played an important role in PF.
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Affiliation(s)
- Tingting Zhao
- Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Tao Ding
- Department of Endocrinology, Xizang Military General Hospital, Lhasa City, China
| | - Zhengyu Sun
- Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China
| | - Xin Shao
- Department of Cardiovascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shuangxi Li
- Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China
| | - Hongtao Lu
- Department of Nutrition, Naval Medical University, Shanghai, China
| | - Ji-Hang Yuan
- Department of Medical Genetics, Naval Medical University, Shanghai, China
| | - Zhiyong Guo
- Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China
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Dow LF, Case AM, Paustian MP, Pinkerton BR, Simeon P, Trippier PC. The evolution of small molecule enzyme activators. RSC Med Chem 2023; 14:2206-2230. [PMID: 37974956 PMCID: PMC10650962 DOI: 10.1039/d3md00399j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/20/2023] [Indexed: 11/19/2023] Open
Abstract
There is a myriad of enzymes within the body responsible for maintaining homeostasis by providing the means to convert substrates to products as and when required. Physiological enzymes are tightly controlled by many signaling pathways and their products subsequently control other pathways. Traditionally, most drug discovery efforts focus on identifying enzyme inhibitors, due to upregulation being prevalent in many diseases and the existence of endogenous substrates that can be modified to afford inhibitor compounds. As enzyme downregulation and reduction of endogenous activators are observed in multiple diseases, the identification of small molecules with the ability to activate enzymes has recently entered the medicinal chemistry toolbox to afford chemical probes and potential therapeutics as an alternative means to intervene in diseases. In this review we highlight the progress made in the identification and advancement of non-kinase enzyme activators and their potential in treating various disease states.
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Affiliation(s)
- Louise F Dow
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
| | - Alfie M Case
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
| | - Megan P Paustian
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
| | - Braeden R Pinkerton
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
| | - Princess Simeon
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
| | - Paul C Trippier
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha NE 68106 USA
- Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center Omaha NE 68106 USA
- UNMC Center for Drug Discovery, University of Nebraska Medical Center Omaha NE 68106 USA
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van Pelt J, Meeusen B, Derua R, Guffens L, Van Cutsem E, Janssens V, Verslype C. Human pancreatic cancer patients with Epithelial-to-Mesenchymal Transition and an aggressive phenotype show a disturbed balance in Protein Phosphatase Type 2A expression and functionality. J Transl Med 2023; 21:317. [PMID: 37170215 PMCID: PMC10176933 DOI: 10.1186/s12967-023-04145-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 04/20/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) has a low survival, its incidence is rising and little therapeutic improvements are expected in the near future. It has been observed that Epithelial-to-Mesenchymal transition (EMT) contributes (including in PDAC) to a more aggressive cancer phenotype. Additionally, largely unexplored, studies indicate a mechanistic interplay between Protein Phosphatase Type 2A (PP2A) enzymes and EMT that could offer treatment opportunities. The aim was to investigate the relation of a PP2A expression signature (encompassing all PP2A subunits, endogenous inhibitors and activators) with EMT and aggressive pancreatic cancer, and to discuss possible implications. METHODS We retrieved different PDAC expression datasets from NCBI to capture the variation in patients, and analyzed these using datamining, survival analysis, differential gene and protein expression. We determined genes highly associated with aggressive PDAC. For in vitro evaluation, Panc-1 cells were treated with the pharmacologic PP2A inhibitor Okadaic Acid (OA). Additionally, two OA-resistant Panc-1 clones were developed and characterized. RESULTS In patients, there is a strong correlation between EMT and aggressive PDAC, and between aggressive PDAC and PP2A, with a significant upregulation of PP2A inhibitor genes. Several PP2A genes significantly correlated with decreased survival. In vitro, short-term exposure to OA induced EMT in Panc-1 cells. This shift towards EMT was further pronounced in the OA-resistant Panc-1 clones, morphologically and by pathway analysis. Proteomic analysis and gene sequencing showed that the advanced OA-resistant model most resembles the clinical PDAC presentation (with EMT signature, and with several specific PP2A genes upregulated, and others downregulated). CONCLUSIONS We demonstrated a strong association between EMT, altered PP2A expression and aggressive PDAC in patients. Also, in vitro, PP2A inhibition induces EMT. Overall, statistics suggests the mechanistic importance of PP2A dysregulation for PDAC progression. Translationally, our observations indicate that pharmacologic restoration of PP2A activity could be an attractive therapeutic strategy to block or reverse progression.
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Affiliation(s)
- Jos van Pelt
- Laboratory of Digestive Oncology, Department of Oncology, KU Leuven & University Hospitals Leuven, Geb. Onderwijs & Navorsing 4, Room 07.465, Herestraat 49, Bus 603, B3000, Leuven, Belgium.
- KU Leuven Cancer Institute (LKI), Herestraat 49, B3000, Leuven, Belgium.
| | - Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, O&N1, University of Leuven (KU Leuven), Herestraat 49, Bus 901, B3000, Leuven, Belgium
| | - Rita Derua
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, O&N1, University of Leuven (KU Leuven), Herestraat 49, Bus 901, B3000, Leuven, Belgium
- SyBioMa (KU Leuven), Herestraat 49, B3000, Leuven, Belgium
| | - Liesbeth Guffens
- KU Leuven Cancer Institute (LKI), Herestraat 49, B3000, Leuven, Belgium
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, O&N1, University of Leuven (KU Leuven), Herestraat 49, Bus 901, B3000, Leuven, Belgium
| | - Eric Van Cutsem
- Laboratory of Digestive Oncology, Department of Oncology, KU Leuven & University Hospitals Leuven, Geb. Onderwijs & Navorsing 4, Room 07.465, Herestraat 49, Bus 603, B3000, Leuven, Belgium
- KU Leuven Cancer Institute (LKI), Herestraat 49, B3000, Leuven, Belgium
| | - Veerle Janssens
- KU Leuven Cancer Institute (LKI), Herestraat 49, B3000, Leuven, Belgium.
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, O&N1, University of Leuven (KU Leuven), Herestraat 49, Bus 901, B3000, Leuven, Belgium.
| | - Chris Verslype
- Laboratory of Digestive Oncology, Department of Oncology, KU Leuven & University Hospitals Leuven, Geb. Onderwijs & Navorsing 4, Room 07.465, Herestraat 49, Bus 603, B3000, Leuven, Belgium
- KU Leuven Cancer Institute (LKI), Herestraat 49, B3000, Leuven, Belgium
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Kim SB, Lee T, Oh YS, Park E, Baek DJ. Synthesis and biological investigation of protein phosphatase
2A
‐activating compounds with dimeric tail as non‐small cell lung cancer cell death agents. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Su Bin Kim
- College of Pharmacy Mokpo National University Jeonnam Korea
| | - Taeho Lee
- College of Pharmacy, Research Institute of Pharmaceutical Sciences Kyungpook National University Daegu Korea
| | - Yoon Sin Oh
- Department of Food and Nutrition Eulji University Seongnam Korea
| | - Eun‐Young Park
- College of Pharmacy Mokpo National University Jeonnam Korea
| | - Dong Jae Baek
- College of Pharmacy Mokpo National University Jeonnam Korea
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Luque M, Cristóbal I, Sanz-Álvarez M, Santos A, Zazo S, Eroles P, Arpí O, Rovira A, Albanell J, Madoz-Gúrpide J, García-Foncillas J, Rojo F. CIP2A as a Key Regulator for AKT Phosphorylation Has Partial Impact Determining Clinical Outcome in Breast Cancer. J Clin Med 2022; 11:jcm11061610. [PMID: 35329936 PMCID: PMC8955826 DOI: 10.3390/jcm11061610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/03/2022] [Accepted: 03/12/2022] [Indexed: 12/07/2022] Open
Abstract
Together with its reported ability to modulate AKT phosphorylation (p-AKT) status in several tumor types, the oncoprotein CIP2A has been described to induce breast cancer progression and drug resistance. However, the clinical and therapeutic relevance of the CIP2A/AKT interplay in breast cancer remains to be fully clarified. Here, we found high p-AKT levels in 80 out of 220 cases (36.4%), which were associated with negative estrogen receptor expression (p = 0.049) and CIP2A overexpression (p < 0.001). Interestingly, p-AKT determined substantially shorter overall (p = 0.002) and progression-free survival (p = 0.003), and multivariate analyses showed its CIP2A-independent prognostic value. Moreover, its clinical relevance was further confirmed in the triple negative and HER2-positive subgroups after stratifying our series by molecular subtype. Functionally, we confirmed in vitro the role of CIP2A as a regulator of p-AKT levels in breast cancer cell lines, and the importance of the CIP2A/AKT axis was also validated in vivo. Finally, p-AKT also showed a higher predictive value of response to doxorubicin than CIP2A in ex vivo analyses. In conclusion, our findings suggest that CIP2A overexpression is a key contributing event to AKT phosphorylation and highlights the CIP2A/AKT axis as a promising therapeutic target in breast cancer. However, our observations highlight the existence of alternative mechanisms that regulate AKT signaling in a subgroup of breast tumors without altered CIP2A expression that determines its independent value as a marker of poor outcome in this disease.
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Affiliation(s)
- Melani Luque
- Pathology Department, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain; (M.L.); (M.S.-Á.); (S.Z.); (J.M.-G.)
| | - Ion Cristóbal
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, ISS-FJD-UAM, 28040 Madrid, Spain;
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain;
- Correspondence: (I.C.); (F.R.); Tel.: +34-915-504-800 (I.C. & F.R.)
| | - Marta Sanz-Álvarez
- Pathology Department, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain; (M.L.); (M.S.-Á.); (S.Z.); (J.M.-G.)
| | - Andrea Santos
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, ISS-FJD-UAM, 28040 Madrid, Spain;
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain;
| | - Sandra Zazo
- Pathology Department, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain; (M.L.); (M.S.-Á.); (S.Z.); (J.M.-G.)
| | - Pilar Eroles
- Institute of Health Research INCLIVA, 46010 Valencia, Spain;
| | - Oriol Arpí
- Medical Oncology Department, Hospital del Mar, 08003 Barcelona, Spain; (O.A.); (A.R.); (J.A.)
| | - Ana Rovira
- Medical Oncology Department, Hospital del Mar, 08003 Barcelona, Spain; (O.A.); (A.R.); (J.A.)
| | - Joan Albanell
- Medical Oncology Department, Hospital del Mar, 08003 Barcelona, Spain; (O.A.); (A.R.); (J.A.)
| | - Juan Madoz-Gúrpide
- Pathology Department, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain; (M.L.); (M.S.-Á.); (S.Z.); (J.M.-G.)
| | - Jesús García-Foncillas
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain;
| | - Federico Rojo
- Pathology Department, IIS-Fundación Jiménez Diaz-UAM, 28040 Madrid, Spain; (M.L.); (M.S.-Á.); (S.Z.); (J.M.-G.)
- Correspondence: (I.C.); (F.R.); Tel.: +34-915-504-800 (I.C. & F.R.)
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Yang JY, Huo YM, Yang MW, Shen Y, Liu DJ, Fu XL, Tao LY, He RZ, Zhang JF, Hua R, Jiang SH, Sun YW, Liu W. SF3B1 mutation in pancreatic cancer contributes to aerobic glycolysis and tumor growth through a PP2A-c-Myc axis. Mol Oncol 2021; 15:3076-3090. [PMID: 33932092 PMCID: PMC8564647 DOI: 10.1002/1878-0261.12970] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/17/2021] [Accepted: 04/16/2021] [Indexed: 12/13/2022] Open
Abstract
Hot spot gene mutations in splicing factor 3b subunit 1 (SF3B1) are observed in many types of cancer and create abundant aberrant mRNA splicing, which is profoundly implicated in tumorigenesis. Here, we identified that the SF3B1 K700E (SF3B1K700E) mutation is strongly associated with tumor growth in pancreatic ductal adenocarcinoma (PDAC). Knockdown of SF3B1 significantly retarded cell proliferation and tumor growth in a cell line (Panc05.04) with the SF3B1K700E mutation. However, SF3B1 knockdown had no notable effect on cell proliferation in two cell lines (BxPC3 and AsPC1) carrying wild‐type SF3B1. Ectopic expression of SF3B1K700E but not SF3B1WT in SF3B1‐knockout Panc05.04 cells largely restored the inhibitory role induced by SF3B1 knockdown. Introduction of the SF3B1K700E mutation in BxPC3 and AsPC1 cells also boosted cell proliferation. Gene set enrichment analysis demonstrated a close correlation between SF3B1 mutation and aerobic glycolysis. Functional analyses showed that the SF3B1K700E mutation promoted tumor glycolysis, as evidenced by glucose consumption, lactate release, and extracellular acidification rate. Mechanistically, the SF3B1 mutation promoted the aberrant splicing of PPP2R5A and led to the activation of the glycolytic regulator c‐Myc via post‐translational regulation. Pharmacological activation of PP2A with FTY‐720 markedly compromised the growth advantage induced by the SF3B1K700E mutation in vitro and in vivo. Taken together, our data suggest a novel function for SF3B1 mutation in the Warburg effect, and this finding may offer a potential therapeutic strategy against PDAC with the SF3B1K700E mutation.
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Affiliation(s)
- Jian-Yu Yang
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yan-Miao Huo
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Min-Wei Yang
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yang Shen
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - De-Jun Liu
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xue-Liang Fu
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ling-Ye Tao
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Rui-Zhe He
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jun-Feng Zhang
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Rong Hua
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shu-Heng Jiang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, China
| | - Yong-Wei Sun
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Liu
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Gupta P, Taiyab A, Hussain A, Alajmi MF, Islam A, Hassan MI. Targeting the Sphingosine Kinase/Sphingosine-1-Phosphate Signaling Axis in Drug Discovery for Cancer Therapy. Cancers (Basel) 2021; 13:1898. [PMID: 33920887 PMCID: PMC8071327 DOI: 10.3390/cancers13081898] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/11/2021] [Accepted: 04/03/2021] [Indexed: 02/07/2023] Open
Abstract
Sphingolipid metabolites have emerged as critical players in the regulation of various physiological processes. Ceramide and sphingosine induce cell growth arrest and apoptosis, whereas sphingosine-1-phosphate (S1P) promotes cell proliferation and survival. Here, we present an overview of sphingolipid metabolism and the compartmentalization of various sphingolipid metabolites. In addition, the sphingolipid rheostat, a fine metabolic balance between ceramide and S1P, is discussed. Sphingosine kinase (SphK) catalyzes the synthesis of S1P from sphingosine and modulates several cellular processes and is found to be essentially involved in various pathophysiological conditions. The regulation and biological functions of SphK isoforms are discussed. The functions of S1P, along with its receptors, are further highlighted. The up-regulation of SphK is observed in various cancer types and is also linked to radio- and chemoresistance and poor prognosis in cancer patients. Implications of the SphK/S1P signaling axis in human pathologies and its inhibition are discussed in detail. Overall, this review highlights current findings on the SphK/S1P signaling axis from multiple angles, including their functional role, mechanism of activation, involvement in various human malignancies, and inhibitor molecules that may be used in cancer therapy.
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Affiliation(s)
- Preeti Gupta
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (P.G.); (A.T.); (A.I.)
| | - Aaliya Taiyab
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (P.G.); (A.T.); (A.I.)
| | - Afzal Hussain
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; (A.H.); (M.F.A.)
| | - Mohamed F. Alajmi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; (A.H.); (M.F.A.)
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (P.G.); (A.T.); (A.I.)
| | - Md. Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (P.G.); (A.T.); (A.I.)
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9
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Expression of Phosphorylated BRD4 Is Markedly Associated with the Activation Status of the PP2A Pathway and Shows a Strong Prognostic Value in Triple Negative Breast Cancer Patients. Cancers (Basel) 2021; 13:cancers13061246. [PMID: 33809005 PMCID: PMC7999847 DOI: 10.3390/cancers13061246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 12/31/2022] Open
Abstract
Simple Summary The use of BRD4 inhibitors has emerged as a novel therapeutic approach in a wide variety of tumors including the triple negative breast cancer. Moreover, PP2A has been proposed as the phosphatase involved in regulating BRD4 phosphorylation and stabilization. Our aim was to evaluate for the first time the clinical impact of BRD4 phosphorylation in triple negative breast cancer patients and as well as its potential linking with the PP2A activation status in this disease. Our findings are special relevant since they suggest the prognostic value of BRD4 phosphorylation levels, and the potential clinical usefulness of PP2A inhibition markers to anticipate response to BRD4 inhibitors. Abstract The bromodomain-containing protein 4 (BRD4), a member of the bromodomain and extra-terminal domain (BET) protein family, has emerged in the last years as a promising molecular target in many tumors including breast cancer. The triple negative breast cancer (TNBC) represents the molecular subtype with the worst prognosis and a current therapeutic challenge, and TNBC cells have been reported to show a preferential sensitivity to BET inhibitors. Interestingly, BRD4 phosphorylation (pBRD4) was found as an alteration that confers resistance to BET inhibition and PP2A proposed as the phosphatase responsible to regulate pBRD4 levels. However, the potential clinical significance of pBRD4, as well as its potential correlation with the PP2A pathway in TNBC, remains to be investigated. Here, we evaluated the expression levels of pBRD4 in a series of 132 TNBC patients. We found high pBRD4 levels in 34.1% of cases (45/132), and this alteration was found to be associated with the development of patient recurrences (p = 0.007). Interestingly, BRD4 hyperphosphorylation predicted significantly shorter overall (p < 0.001) and event-free survival (p < 0.001). Moreover, multivariate analyses were performed to confirm its independent prognostic impact in our cohort. In conclusion, our findings show that BRD4 hyperphosphorylation is an alteration associated with PP2A inhibition that defines a subgroup of TNBC patients with unfavorable prognosis, suggesting the potential clinical and therapeutic usefulness of the PP2A/BRD4 axis as a novel molecular target to overcome resistance to treatments based on BRD4 inhibition.
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10
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Subbiah S, Nam A, Garg N, Behal A, Kulkarni P, Salgia R. Small Cell Lung Cancer from Traditional to Innovative Therapeutics: Building a Comprehensive Network to Optimize Clinical and Translational Research. J Clin Med 2020; 9:jcm9082433. [PMID: 32751469 PMCID: PMC7464169 DOI: 10.3390/jcm9082433] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/23/2022] Open
Abstract
Small cell lung cancer (SCLC) is an aggressive, complex disease with a distinct biology that contributes to its poor prognosis. Management of SCLC is still widely limited to chemotherapy and radiation therapy, and research recruitment still poses a considerable challenge. Here, we review the current standard of care for SCLC and advances made in utilizing immunotherapy. We also highlight research in the development of targeted therapies and emphasize the importance of a team-based approach to make clinical advances. Building an integrative network between an academic site and community practice sites optimizes biomarker and drug target discovery for managing and treating a difficult disease like SCLC.
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Cristóbal I, Rubio J, Santos A, Torrejón B, Caramés C, Imedio L, Mariblanca S, Luque M, Sanz-Alvarez M, Zazo S, Madoz-Gúrpide J, Rojo F, García-Foncillas J. MicroRNA-199b Downregulation Confers Resistance to 5-Fluorouracil Treatment and Predicts Poor Outcome and Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Patients. Cancers (Basel) 2020; 12:cancers12061655. [PMID: 32580513 PMCID: PMC7352382 DOI: 10.3390/cancers12061655] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/18/2020] [Accepted: 06/18/2020] [Indexed: 12/17/2022] Open
Abstract
Neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy followed by mesorectal excision is the current standard treatment in locally advanced rectal cancer (LARC) and the lack of complete response represents a major problem that compromises long-term patient survival. However, there is a lack of robust established markers predictive of response to this preoperative treatment available in the clinical routine. The tumor suppressor microRNA (miR)-199b directly targets the PP2A inhibitor SET, which has been involved in 5-FU resistance, and its downregulation has been found to correlate with poor outcome in metastatic colorectal cancer. Here, we studied the functional effects of miR-199b on 5-FU sensitivity after its ectopic modulation, and its expression was quantified by real-time-PCR in a cohort of 110 LARC patients to evaluate its potential clinical significance. Interestingly, our findings demonstrate that miR-199b enhances the sensitivity of colorectal cancer cells to 5-FU in a SET-dependent manner, and that both miR-199b overexpression and SET inhibition are able to overcome resistance to this drug using an acquired 5-FU-resistant model. MiR-199b was found downregulated in 26.4% of cases and was associated with positive lymph node levels after chemoradiotherapy (CRT, p = 0.007) and high pathological stage (p = 0.029). Moreover, miR-199b downregulation determined shorter overall (p = 0.003) and event-free survival (p = 0.005), and was an independent predictor of poor response to preoperative CRT (p = 0.004). In conclusion, our findings highlight the clinical impact of miR-199b downregulation predicting poor outcome and pathological response in LARC, and suggest the miR-199b/SET signaling axis as a novel molecular target to prevent the development of resistance to 5-FU treatment.
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Affiliation(s)
- Ion Cristóbal
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
- Correspondence: (I.C.); (J.G.-F.); Tel.: +34-915504800 (I.C. & J.G.-F.)
| | - Jaime Rubio
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Medical Oncology Department, University Hospital “Fundación Jiménez Díaz”, UAM, E-28040 Madrid, Spain
| | - Andrea Santos
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
| | - Blanca Torrejón
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
| | - Cristina Caramés
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Medical Oncology Department, University Hospital “Fundación Jiménez Díaz”, UAM, E-28040 Madrid, Spain
| | - Laura Imedio
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
| | - Sofía Mariblanca
- Cancer Unit for Research on Novel Therapeutic Targets, Oncohealth Institute, IIS- Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (J.R.); (A.S.); (B.T.); (C.C.); (L.I.); (S.M.)
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
| | - Melani Luque
- Pathology Department, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (M.L.); (M.S.-A.); (S.Z.); (J.M.-G.); (F.R.)
| | - Marta Sanz-Alvarez
- Pathology Department, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (M.L.); (M.S.-A.); (S.Z.); (J.M.-G.); (F.R.)
| | - Sandra Zazo
- Pathology Department, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (M.L.); (M.S.-A.); (S.Z.); (J.M.-G.); (F.R.)
| | - Juan Madoz-Gúrpide
- Pathology Department, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (M.L.); (M.S.-A.); (S.Z.); (J.M.-G.); (F.R.)
| | - Federico Rojo
- Pathology Department, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain; (M.L.); (M.S.-A.); (S.Z.); (J.M.-G.); (F.R.)
| | - Jesús García-Foncillas
- Translational Oncology Division, Oncohealth Institute, IIS-Fundación Jiménez Díaz-UAM, E-28040 Madrid, Spain
- Medical Oncology Department, University Hospital “Fundación Jiménez Díaz”, UAM, E-28040 Madrid, Spain
- Correspondence: (I.C.); (J.G.-F.); Tel.: +34-915504800 (I.C. & J.G.-F.)
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Reduced Expression of the PP2A Methylesterase, PME-1, or the PP2A Methyltransferase, LCMT-1, Alters Sensitivity to Beta-Amyloid-Induced Cognitive and Electrophysiological Impairments in Mice. J Neurosci 2020; 40:4596-4608. [PMID: 32341098 DOI: 10.1523/jneurosci.2983-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/27/2020] [Accepted: 04/17/2020] [Indexed: 12/16/2022] Open
Abstract
Beta-amyloid (Aβ) is thought to play a critical role in Alzheimer's disease (AD), and application of soluble oligomeric forms of Aβ produces AD-like impairments in cognition and synaptic plasticity in experimental systems. We found previously that transgenic overexpression of the PP2A methylesterase, PME-1, or the PP2A methyltransferase, LCMT-1, altered the sensitivity of mice to Aβ-induced impairments, suggesting that PME-1 inhibition may be an effective approach for preventing or treating these impairments. To explore this possibility, we examined the behavioral and electrophysiological effects of acutely applied synthetic Aβ oligomers in male and female mice heterozygous for either a PME-1 KO or an LCMT-1 gene-trap mutation. We found that heterozygous PME-1 KO mice were resistant to Aβ-induced impairments in cognition and synaptic plasticity, whereas LCMT-1 gene-trap mice showed increased sensitivity to Aβ-induced impairments. The heterozygous PME-1 KO mice produced normal levels of endogenous Aβ and exhibited normal electrophysiological responses to picomolar concentrations of Aβ, suggesting that reduced PME-1 expression in these animals protects against Aβ-induced impairments without impacting normal physiological Aβ functions. Together, these data provide additional support for roles for PME-1 and LCMT-1 in regulating sensitivity to Aβ-induced impairments, and suggest that inhibition of PME-1 may constitute a viable therapeutic approach for selectively protecting against the pathologic actions of Aβ in AD.SIGNIFICANCE STATEMENT Elevated levels of β-amyloid (Aβ) in the brain are thought to contribute to the cognitive impairments observed in Alzheimer's disease patients. Here we show that genetically reducing endogenous levels of the PP2A methylesterase, PME-1, prevents the cognitive and electrophysiological impairments caused by acute exposure to pathologic concentrations of Aβ without impairing normal physiological Aβ function or endogenous Aβ production. Conversely, reducing endogenous levels of the PP2A methyltransferase, LCMT-1, increases sensitivity to Aβ-induced impairments. These data offer additional insights into the molecular factors that control sensitivity to Aβ-induced impairments, and suggest that inhibiting PME-1 may constitute a viable therapeutic avenue for preventing Aβ-related impairments in Alzheimer's disease.
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Abstract
MYC is a master transcriptional regulator that controls almost all cellular processes. Over the last several decades, researchers have strived to define the context-dependent transcriptional gene programs that are controlled by MYC, as well as the mechanisms that regulate MYC function, in an effort to better understand the contribution of this oncoprotein to cancer progression. There are a wealth of data indicating that deregulation of MYC activity occurs in a large number of cancers and significantly contributes to disease progression, metastatic potential, and therapeutic resistance. Although the therapeutic targeting of MYC in cancer is highly desirable, there remain substantial structural and functional challenges that have impeded direct MYC-targeted drug development and efficacy. While efforts to drug the ‘undruggable’ may seem futile given these challenges and considering the broad reach of MYC, significant strides have been made to identify points of regulation that can be exploited for therapeutic purposes. These include targeting the deregulation of MYC transcription in cancer through small-molecule inhibitors that induce epigenetic silencing or that regulate the G-quadruplex structures within the MYC promoter. Alternatively, compounds that disrupt the DNA-binding activities of MYC have been the long-standing focus of many research groups, since this method would prevent downstream MYC oncogenic activities regardless of upstream alterations. Finally, proteins involved in the post-translational regulation of MYC have been identified as important surrogate targets to reduce MYC activity downstream of aberrant cell stimulatory signals. Given the complex regulation of the MYC signaling pathway, a combination of these approaches may provide the most durable response, but this has yet to be shown. Here, we provide a comprehensive overview of the different therapeutic strategies being employed to target oncogenic MYC function, with a focus on post-translational mechanisms.
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Camp SM, Marciniak A, Chiang ET, Garcia AN, Bittman R, Polt R, Perez RG, Dudek SM, Garcia JGN. Sphingosine-1-phosphate receptor-independent lung endothelial cell barrier disruption induced by FTY720 regioisomers. Pulm Circ 2020; 10:10.1177_2045894020905521. [PMID: 32095229 PMCID: PMC7011338 DOI: 10.1177/2045894020905521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/16/2020] [Indexed: 12/27/2022] Open
Abstract
RATIONALE Vascular permeability is a hallmark of acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury pathobiology; however, the mechanisms underlying this vascular dysregulation remain unclear, thereby impairing the development of desperately needed effective therapeutics. We have shown that sphingosine-1-phosphate (S1P) and 2-amino-2-(2-[4-octylphenyl]ethyl)-1,3-propanediol (FTY720) analogues are useful tools for exploring vascular barrier regulation mechanisms. OBJECTIVE To experimentally define the effects of FTY720 regioisomers on lung endothelial cell barrier regulation. METHODS Specific barrier-regulatory receptor and kinase inhibitors were utilized to probe signaling mechanisms involved in FTY720 regioisomer-mediated human lung endothelial cell barrier responses (trans-endothelial electrical resistance, TER). Docking simulations with the S1P1 receptor were performed to further evaluate FTY720 regioisomer signaling. RESULTS FTY720 regioisomers produced potent endothelial cell barrier disruption reflected by declines in TER alterations. Pharmacologic inhibition of Gi-coupled S1P receptors (S1P1, S1P2, S1P3) failed to alter FTY720 regioisomer-mediated barrier disruption; findings that were corroborated by docking simulations demonstrating FTY720 regiosomers were repelled from S1P1 docking, in contrast to strong S1P1 binding elicited by S1P. Inhibition of either the barrier-disrupting PAR-1 receptor, the VEGF receptor, Rho-kinase, MAPK, NFkB, or PI3K failed to alter FTY720 regioisomer-induced endothelial cell barrier disruption. While FTY720 regioisomers significantly increased protein phosphatase 2 (PP2A) activity, PP2A inhibitors failed to alter FTY720 regioisomer-induced endothelial cell barrier disruption. CONCLUSIONS Together, these results imply a vexing model of pulmonary vascular barrier dysregulation in response to FTY720-related compounds and highlight the need for further insights into mechanisms of vascular integrity required to promote the development of novel therapeutic tools to prevent or reverse the pulmonary vascular leak central to ARDS outcomes.
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Affiliation(s)
- Sara M. Camp
- Department of Medicine, The University of Arizona, Tucson, AZ, USA
| | - Alexander Marciniak
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, USA
| | - Eddie T. Chiang
- Department of Medicine, The University of Arizona, Tucson, AZ, USA
| | - Alexander N. Garcia
- Department of Radiation Oncology, The University of Arizona, Tucson, AZ, USA
| | - Robert Bittman
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, Flushing, NY, USA
| | - Robin Polt
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, USA
| | - Ruth G. Perez
- Department of Molecular and Translational Medicine, Graduate School of Biomedical Sciences, Center of Emphasis in Neuroscience, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Steven M. Dudek
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Joe G. N. Garcia
- Department of Medicine, The University of Arizona, Tucson, AZ, USA
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15
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Synthesis and Biological Evaluation of BODIPY-PF-543. Molecules 2019; 24:molecules24234408. [PMID: 31810327 PMCID: PMC6930633 DOI: 10.3390/molecules24234408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/29/2019] [Accepted: 11/30/2019] [Indexed: 01/22/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) regulates the proliferation of various cells and promotes the growth of cancer cells. Sphingosine kinase (SK), which transforms sphingosine into S1P, has two isotypes: SK1 and SK2. To date, both isotypes are known to be involved in the proliferation of cancer cells. PF-543, an SK1 inhibitor developed by Pfizer, strongly inhibits SK1. However, despite its strong SK1 inhibitory effect, PF-543 shows low anticancer activity in vitro. Therefore, additional biological evidence on the anticancer activity of SK1 inhibitor is required. The present study aimed to investigate the intracellular localization of PF-543 and identify its association with anticancer activity by introducing a fluoroprobe into PF-543. Boron–dipyrromethene (BODIPY)-introduced PF-543 has a similar SK1 inhibitory effect as PF-543. These results indicate that the introduction of BODIPY does not significantly affect the inhibitory effect of SK1. In confocal microscopy after BODIPY-PF-543 treatment, the compound was mainly located in the cytosol of the cells. This study demonstrated the possibility of introducing fluorescent material into an SK inhibitor and designing a synthesized compound that is permeable to cells while maintaining the SK inhibitory effect.
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Yao S, Li L, Sun X, Hua J, Zhang K, Hao L, Liu L, Shi D, Zhou H. FTY720 Inhibits MPP +-Induced Microglial Activation by Affecting NLRP3 Inflammasome Activation. J Neuroimmune Pharmacol 2019; 14:478-492. [PMID: 31069623 DOI: 10.1007/s11481-019-09843-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/25/2019] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons and excessive microglial activation in the substantia nigra pars compacta (SNpc). In the present study, we aimed to demonstrate the therapeutic effectiveness of the potent sphingosine-1-phosphate receptor antagonist fingolimod (FTY720) in an animal model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and to identify the potential mechanisms underlying these therapeutic effects. C57BL/6J mice were orally administered FTY720 before subcutaneous injection of MPTP. Open-field and rotarod tests were performed to determine the therapeutic effect of FTY720. The damage to dopaminergic neurons and the production of monoamine neurotransmitters were assessed using immunohistochemistry, high-performance liquid chromatography, and flow cytometry. Immunofluorescence (CD68- positive) and enzyme-linked immunosorbent assay were used to analyze the activation of microglia, and the levels of activated signaling molecules were measured using Western blotting. Our findings indicated that FTY720 significantly attenuated MPTP-induced behavioral deficits, reduced the loss of dopaminergic neurons, and increased dopamine release. FTY720 directly inhibited MPTP-induced microglial activation in the SNpc, suppressed the production of interleukin (IL)-6, IL-1β, and tumor necrosis factor-α in BV-2 microglial cells treated with 1-methyl-4-phenylpyridinium (MPP+), and subsequently decreased apoptosis in SH-SY5Y neuroblastoma cells. Moreover, in MPP+-treated BV-2 cells and primary microglia, FTY720 treatment significantly attenuated the increases in the phosphorylation of PI3K/AKT/GSK-3β, reduced ROS generation and p65 activation, and also inhibited the activation of NLRP3 inflammasome and caspase-1. In conclusion, FTY720 may reduce PD progression by inhibiting NLRP3 inflammasome activation via its effects on ROS generation and p65 activation in microglia. These findings provide novel insights into the mechanisms underlying the therapeutic effects of FTY720, suggesting its potential as a novel therapeutic strategy against PD. Graphical Abstract FTY720 may reduce ROS production by inhibiting the PI3K/AKT/GSK-3β signaling pathway, while at the same time reducing p65 phosphorylation, thus decreasing NLRP3 inflammasome activation through these two pathways, ultimately reducing microglia activation-induced neuronal damage.
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Affiliation(s)
- Shu Yao
- Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, JS, China
| | - Longjun Li
- Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, JS, China
| | - Xin Sun
- Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, JS, China
| | - Jun Hua
- Department of Clinical Pharmacy, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, No. 1, Fuhua Road, Futian District, Shenzhen, 518033, Guangdong, China
| | - Keqi Zhang
- Institute of Microscope Science and Technology, Ningbo Yongxin Optics Co. Ltd., 385 Mingzhu Road, Hi-tech Industry Park, Ningbo, 315040, China
| | - Li Hao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK, S7N 5E5, Canada
| | - Lixin Liu
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK, S7N 5E5, Canada
| | - Dongyan Shi
- Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, JS, China.
| | - Hong Zhou
- Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, JS, China.
- Department of Biotherapy, Second Affiliated Hospital, Nanjing Medical University, Nanjing, 210011, Jiangsu, China.
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Clark AR, Ohlmeyer M. Protein phosphatase 2A as a therapeutic target in inflammation and neurodegeneration. Pharmacol Ther 2019; 201:181-201. [PMID: 31158394 PMCID: PMC6700395 DOI: 10.1016/j.pharmthera.2019.05.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/11/2022]
Abstract
Protein phosphatase 2A (PP2A) is a highly complex heterotrimeric enzyme that catalyzes the selective removal of phosphate groups from protein serine and threonine residues. Emerging evidence suggests that it functions as a tumor suppressor by constraining phosphorylation-dependent signalling pathways that regulate cellular transformation and metastasis. Therefore, PP2A-activating drugs (PADs) are being actively sought and investigated as potential novel anti-cancer treatments. Here we explore the concept that PP2A also constrains inflammatory responses through its inhibitory effects on various signalling pathways, suggesting that PADs may be effective in the treatment of inflammation-mediated pathologies.
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Affiliation(s)
- Andrew R Clark
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
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Deregulation of SET is Associated with Tumor Progression and Predicts Adverse Outcome in Patients with Early-Stage Colorectal Cancer. J Clin Med 2019; 8:jcm8030346. [PMID: 30871013 PMCID: PMC6463201 DOI: 10.3390/jcm8030346] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 12/26/2022] Open
Abstract
SET nuclear proto-oncogene (SET) deregulation is a novel molecular target in metastatic colorectal cancer (CRC). However, its role in CRC progression and its potential clinical impact in early-stage CRC patients remain unknown. Here, we studied the biological effects of SET on migration using wound-healing and transwell assays, and anchorage-independent cell growth using soft agar colony formation assays after ectopic SET modulation. SET was analyzed by immuno-staining in 231 early-stage CRC patients, and miR-199b expression was quantified by real-time PCR in a set of CRC patients. Interestingly, SET enhances cell migration, markedly affects the colony-forming ability, promotes epithelial to mesenchymal transition, and induces the expression of the MYC proto-oncogene (c-MYC) in CRC cells. SET overexpression was detected in 15.4% of cases and was associated with worse Eastern Cooperative Oncology Group (ECOG) status (p = 0.021) and relapse in stage-II CRC patients (p = 0.008). Moreover, SET overexpression predicted shorter overall survival (p < 0.001) and time to metastasis (p < 0.001), and its prognostic value was particularly evident in elderly patients. MiR-199b downregulation was identified as a molecular mechanism to deregulate SET in patients with localized disease. In conclusion, SET overexpression is a common alteration in early-stage CRC, playing an oncogenic role associated with progression and aggressiveness, and portends a poor outcome. Thus, SET emerges as a novel potential molecular target with clinical impact in early-stage in CRC.
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Targeting SET to restore PP2A activity disrupts an oncogenic CIP2A-feedforward loop and impairs triple negative breast cancer progression. EBioMedicine 2019; 40:263-275. [PMID: 30651219 PMCID: PMC6412013 DOI: 10.1016/j.ebiom.2018.12.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/13/2018] [Accepted: 12/17/2018] [Indexed: 12/29/2022] Open
Abstract
Background Triple-negative breast cancer (TNBC) remains difficult to be targeted. SET and cancerous inhibitor of protein phosphatase 2A (CIP2A) are intrinsic protein-interacting inhibitors of protein phosphatase 2A (PP2A) and frequently overexpressed in cancers, whereas reactivating PP2A activity has been postulated as an anti-cancer strategy. Here we explored this strategy in TNBC. Methods Data from The Cancer Genome Atlas (TCGA) database was analyzed. TNBC cell lines were used for in vitro studies. Cell viability was examined by MTT assay. The apoptotic cells were examined by flow cytometry and Western blot. A SET-PP2A protein-protein interaction antagonist TD19 was used to disrupt signal transduction. In vivo efficacy of TD19 was tested in MDA-MB-468-xenografted animal model. Findings TCGA data revealed upregulation of SET and CIP2A and positive correlation of these two gene expressions in TNBC tumors. Ectopic SET or CIP2A increased cell viability, migration, and invasion of TNBC cells. Notably ERK inhibition increased PP2A activity. ERK activation is known crucial for Elk-1 activity, a transcriptional factor regulating CIP2A expression, we hypothesized an oncogenic feedforward loop consisting of pERK/pElk-1/CIP2A/PP2A. This loop was validated by knockdown of PP2A and ectopic expression of Elk-1, showing reciprocal changes in loop members. In addition, ectopic expression of SET increased pAkt, pERK, pElk-1 and CIP2A expressions, suggesting a positive linkage between SET and CIP2A signaling. Moreover, TD19 disrupted this CIP2A-feedforward loop by restoring PP2A activity, demonstrating in vitro and in vivo anti-cancer activity. Mechanistically, TD19 downregulated CIP2A mRNA via inhibiting pERK-mediated Elk-1 nuclear translocation thereby decreased Elk-1 binding to the CIP2A promoter. Interpretation These findings suggested that a novel oncogenic CIP2A-feedforward loop contributes to TNBC progression and targeting SET to disrupt this oncogenic CIP2A loop showed therapeutic potential in TNBC.
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Protein phosphatase 2A activation mechanism contributes to JS-K induced caspase-dependent apoptosis in human hepatocellular carcinoma cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2018; 37:142. [PMID: 29986744 PMCID: PMC6038275 DOI: 10.1186/s13046-018-0823-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 07/03/2018] [Indexed: 12/11/2022]
Abstract
Background JS-K is a nitric oxide (NO) donor and could generate intracellularly high levels of NO. The study explores PP2A as a tumor suppressor is a major determinant mediating JS-K-caused apoptosis in human hepatocellular carcinoma (HCC) cells. Methods The human HCC cell lines (PLC5, Huh-7, Bel-7402, SMMC-7721 and HepG2) were used to assess effects of JS-K on cell viability, apoptosis induction and PP2A activation. Effects of JS-K on cell morphology, mitochondrial membrane potential, apoptosis and NO levels were determined in HCC cells expressing PP2A. Simultaneously, the expression of PP2A family including PP2A-A(α/β), PP2A-B55, PP2A-C(α/β) and the substrates of PP2A, such as β-catenin, c-Myc and p-Bcl-2 (Ser70) were detected in sensitive HCC cells. Furthermore, the role of NO in mediating the expression of PP2A was further validated with Z-VAD-FMK (a caspase inhibitor), Carboxy-PTIO (a NO scavenger), okadaic acid (OA, a PP2A inhibitor) and FTY720 (a PP2A agonist) in JS-K treated cells. In addition, the genetic manuplation of PP2A including overexpression and knockdown have been also performed in JS-K treated cells. Moreover, the rat model of primary hepatic carcinoma was established with diethylnitrosamine for 16 weeks to verify the anti-tumor effects of JS-K in vivo. Immunohistochemical and Western blot analysis were used to determine the expression of proteins in rat primary hepatic carcinoma tissues. Results JS-K significantly inhibited cell proliferation, increased apoptosis rate and activated PP2A activity in five HCC cells viability, especially SMMC7721 and HepG2 cells. It was characterized by loss of mitochondrial membrane potential, significant externalization of phosphatidylserine, nuclear morphological changes. Moreover, JS-K enhanced Bax-to-Bcl-2 ratio, released cytochrome c (Cyt c) from mitochondria, activated cleaved-caspase-9/3 and the cleavage of PARP, and decreased the expression of X-linked inhibitor of apoptosis protein (XIAP). Both Z-VAD-FMK and Carboxy-PTIO suppressed the activation of cleaved-caspase-9/3 and of cleaved-PARP in JS-K-treated sensitive HCC cells. Simultaneously, JS-K treatment could lead to the activation of protein phosphatase 2A-C (PP2A-C) but not PP2A-A and PP2A-B55, which subsequently inactivated and dephosphorylated the PP2A substrates including β-catenin, c-Myc, and p-Bcl-2 (Ser70). However, silencing PP2A-C could abolish both the activation of PP2A-C and down-regulation of β-catenin, c-Myc and p-Bcl-2 (Ser70) in sensitive HCC cells. Conversely, PP2A overexpression could enhance the effects of JS-K on activation of PP2A and down-regulation of β-catenin, c-Myc and p-Bcl-2 (Ser70). In addition, adding okadaic acid (OA), a PP2A inhibitor, abolished the effects of JS-K on apoptosis induction, PP2A activation and the substrates of PP2A dephosphorylation; FTY720, a PP2A agonist, enhanced the effects of JS-K including apoptosis induction, PP2A activation and the substrates of PP2A dephosphorylation. The mice exhibited a lower number and smaller tumor nodules in response to JS-K-treated group. A marked increase in the number of hepatocytes with PCNA-positive nuclei (proliferating cells) was evident in DEN group and tended to decrease with JS-K treatment. Furthermore, JS-K treatment could induce PP2A activation and the substrates of PP2A inactivation such as β-catenin, c-Myc and p-Bcl-2(Ser70) in DEN-induced hepatocarcinogenesis. Conclusions High levels of NO released from JS-K induces a caspase-dependent apoptosis through PP2A activation.
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Huwiler A, Zangemeister-Wittke U. The sphingosine 1-phosphate receptor modulator fingolimod as a therapeutic agent: Recent findings and new perspectives. Pharmacol Ther 2018; 185:34-49. [DOI: 10.1016/j.pharmthera.2017.11.001] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
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Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
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Overexpression of phosphoprotein phosphatase 2A predicts worse prognosis in patients with breast cancer: a 15-year follow-up. Hum Pathol 2017; 66:93-100. [PMID: 28603063 DOI: 10.1016/j.humpath.2017.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/26/2017] [Accepted: 06/01/2017] [Indexed: 12/15/2022]
Abstract
Breast cancer subtypes can be stratified by IHC expression of estrogen receptor, progesterone receptor, and human epidermal growth factor 2 (HER2). The signaling pathways mediated by these receptors are the dominant drivers of cell proliferation and survival in most human breast cancers. One of the most frequently overactivated pathways in breast cancer is the AKT signaling cascade. Protein phosphatase 2A (PP2A) acts as a switch to turn off signal transduction in the AKT pathway; however, it is frequently inactivated in many cancers by phosphorylation of Tyr-307 to form phosphoprotein phosphatase 2A (p-PP2A). This study aimed to investigate the clinical significance of p-PP2A and phospho-AKT (p-AKT) expression in 672 patients with breast cancer during a 15-year follow-up. The breast tissue microarray was evaluated for p-PP2A and p-AKT expression using IHC staining and scores. Analysis of IHC staining results revealed that p-PP2A expression was positively correlated with HER2, Ki-67, and p-AKT overexpression (P<.001, P=.003, and P=.001, respectively). At the time of diagnosis, breast cancer patients with higher p-PP2A expression had significantly shorter 15-year OS than patients with lower p-PP2A expression did (P=.017). Multivariate Cox regression analysis revealed that high p-PP2A expression was an independent prognostic factor for shorter OS (hazard ratio, 1.741; P=.012). Our data revealed that high p-PP2A expression is positively associated with HER2, Ki-67, and p-AKT expression. High p-PP2A expression correlates with poor clinical outcomes in breast cancer, especially in patients with TNBC.
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McHugh WM, Russell WW, Fleszar AJ, Rodenhouse PE, Rietberg SP, Sun L, Shanley TP, Cornell TT. Protein phosphatase 2A activation attenuates inflammation in murine models of acute lung injury. Am J Physiol Lung Cell Mol Physiol 2016; 311:L903-L912. [PMID: 27638902 DOI: 10.1152/ajplung.00007.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 09/11/2016] [Indexed: 12/27/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) remains a leading cause of morbidity and mortality in both adult and pediatric intensive care units. A key event in the development of ARDS is neutrophil recruitment into the lungs leading to tissue damage and destruction. Interleukin-8 (IL-8) is the major human chemokine responsible for neutrophil recruitment into the lungs. Protein phosphatase 2A (PP2A) has been shown to be a key regulator of the mitogen-activated protein kinase (MAPK) cascades, which control the production of IL-8. Previously, our laboratory employed an in vitro model to show that inhibition of PP2A results in an increase in IL-8 production in human alveolar epithelial cells. The objective of this study was to determine whether PP2A regulated this response in vivo by investigating the impact of pharmacologic activation of PP2A on chemokine production and activation of the MAPK cascade and lung injury using endotoxin- and bacterial-challenge models of ARDS in mice. N6-cyclopentyladenosine (N6-CPA) increased PP2A activity and inhibited endotoxin-induced cytokine production in a murine alveolar macrophage cell line. N6-CPA pretreatment in mice challenged with intratracheal endotoxin decreased chemokine production, reduced neutrophil infiltration, and attenuated lung injury. Following initiation of lung injury with live Pseudomonas aeruginosa, mice that received N6-CPA 4 h following bacterial challenge showed attenuated chemokine production and reduced neutrophil infiltration compared with control mice. Pharmacologic PP2A activation both limited and prevented inflammation and tissue injury in two direct injury models of ARDS. These results suggest modulation of PP2A activity as a therapeutic target in ARDS.
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Affiliation(s)
- Walker M McHugh
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - William W Russell
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Andrew J Fleszar
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Paul E Rodenhouse
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Skyler P Rietberg
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Lei Sun
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Thomas P Shanley
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
| | - Timothy T Cornell
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, and C. S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan
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The broken "Off" switch in cancer signaling: PP2A as a regulator of tumorigenesis, drug resistance, and immune surveillance. BBA CLINICAL 2016; 6:87-99. [PMID: 27556014 PMCID: PMC4986044 DOI: 10.1016/j.bbacli.2016.08.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 12/31/2022]
Abstract
Aberrant activation of signal transduction pathways can transform a normal cell to a malignant one and can impart survival properties that render cancer cells resistant to therapy. A diverse set of cascades have been implicated in various cancers including those mediated by serine/threonine kinases such RAS, PI3K/AKT, and PKC. Signal transduction is a dynamic process involving both "On" and "Off" switches. Activating mutations of RAS or PI3K can be viewed as the switch being stuck in the "On" position resulting in continued signaling by a survival and/or proliferation pathway. On the other hand, inactivation of protein phosphatases such as the PP2A family can be seen as the defective "Off" switch that similarly can activate these pathways. A problem for therapeutic targeting of PP2A is that the enzyme is a hetero-trimer and thus drug targeting involves complex structures. More importantly, since PP2A isoforms generally act as tumor suppressors one would want to activate these enzymes rather than suppress them. The elucidation of the role of cellular inhibitors like SET and CIP2A in cancer suggests that targeting these proteins can have therapeutic efficacy by mechanisms involving PP2A activation. Furthermore, drugs such as FTY-720 can activate PP2A isoforms directly. This review will cover the current state of knowledge of PP2A role as a tumor suppressor in cancer cells and as a mediator of processes that can impact drug resistance and immune surveillance.
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