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Epigenetic Regulation Mediated by Sphingolipids in Cancer. Int J Mol Sci 2023; 24:ijms24065294. [PMID: 36982369 PMCID: PMC10048860 DOI: 10.3390/ijms24065294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Epigenetic changes are heritable modifications that do not directly affect the DNA sequence. In cancer cells, the maintenance of a stable epigenetic profile can be crucial to support survival and proliferation, and said profile can differ significantly from that of healthy cells. The epigenetic profile of a cancer cell can be modulated by several factors, including metabolites. Recently, sphingolipids have emerged as novel modulators of epigenetic changes. Ceramide and sphingosine 1-phosphate have become well known in cancer due to activating anti-tumour and pro-tumour signalling pathways, respectively, and they have recently been shown to also induce several epigenetic modifications connected to cancer growth. Additionally, acellular factors in the tumour microenvironment, such as hypoxia and acidosis, are now recognised as crucial in promoting aggressiveness through several mechanisms, including epigenetic modifications. Here, we review the existing literature on sphingolipids, cancer, and epigenetic changes, with a focus on the interaction between these elements and components of the chemical tumour microenvironment.
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Bownes LV, Marayati R, Quinn CH, Beierle AM, Hutchins SC, Julson JR, Erwin MH, Stewart JE, Mroczek-Musulman E, Ohlmeyer M, Aye JM, Yoon KJ, Beierle EA. Pre-Clinical Study Evaluating Novel Protein Phosphatase 2A Activators as Therapeutics for Neuroblastoma. Cancers (Basel) 2022; 14:1952. [PMID: 35454859 PMCID: PMC9026148 DOI: 10.3390/cancers14081952] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Protein phosphatase 2A (PP2A) functions as an inhibitor of cancer cell proliferation, and its tumor suppressor function is attenuated in many cancers. Previous studies utilized FTY720, an immunomodulating compound known to activate PP2A, and demonstrated a decrease in the malignant phenotype in neuroblastoma. We wished to investigate the effects of two novel PP2A activators, ATUX-792 (792) and DBK-1154 (1154). METHODS Long-term passage neuroblastoma cell lines and human neuroblastoma patient-derived xenograft (PDX) cells were used. Cells were treated with 792 or 1154, and viability, proliferation, and motility were examined. The effect on tumor growth was investigated using a murine flank tumor model. RESULTS Treatment with 792 or 1154 resulted in PP2A activation, decreased cell survival, proliferation, and motility in neuroblastoma cells. Immunoblotting revealed a decrease in MYCN protein expression with increasing concentrations of 792 and 1154. Treatment with 792 led to tumor necrosis and decreased tumor growth in vivo. CONCLUSIONS PP2A activation with 792 or 1154 decreased survival, proliferation, and motility of neuroblastoma in vitro and tumor growth in vivo. Both compounds resulted in decreased expression of the oncogenic protein MYCN. These findings indicate a potential therapeutic role for these novel PP2A activators in neuroblastoma.
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Affiliation(s)
- Laura V. Bownes
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Raoud Marayati
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Colin H. Quinn
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Andee M. Beierle
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Sara C. Hutchins
- Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (S.C.H.); (J.M.A.)
| | - Janet R. Julson
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Michael H. Erwin
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | - Jerry E. Stewart
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
| | | | | | - Jamie M. Aye
- Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (S.C.H.); (J.M.A.)
| | - Karina J. Yoon
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Elizabeth A. Beierle
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (L.V.B.); (R.M.); (C.H.Q.); (A.M.B.); (J.R.J.); (M.H.E.); (J.E.S.)
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Hao J, Ci X, Wang Y, Choi SYC, Sullivan SE, Xue H, Wu R, Dong X, Haegert AM, Collins CC, Lin D, Wang Y. GRB10 sustains AR activity by interacting with PP2A in prostate cancer cells. Int J Cancer 2020; 148:469-480. [PMID: 33038264 DOI: 10.1002/ijc.33335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/06/2020] [Accepted: 09/30/2020] [Indexed: 01/22/2023]
Abstract
Prostate cancer (PCa) progression is driven by androgen receptor (AR) signaling. Unfortunately, androgen-deprivation therapy and the use of even more potent AR pathway inhibitors (ARPIs) cannot bring about a cure. ARPI resistance (ie, castration-resistant PCa, CRPC) will inevitably develop. Previously, we demonstrated that GRB10 is an AR transcriptionally repressed gene that functionally contributes to CRPC development and ARPI resistance. GRB10 expression is elevated prior to CRPC development in our patient-derived xenograft models and is significantly upregulated in clinical CRPC samples. Here, we analyzed transcriptomic data from GRB10 knockdown in PCa cells and found that AR signaling is downregulated. While the mRNA expression of AR target genes decreased upon GRB10 knockdown, AR expression was not affected at the mRNA or protein level. We further found that phosphorylation of AR serine 81 (S81), which is critical for AR transcriptional activity, is decreased by GRB10 knockdown and increased by its overexpression. Luciferase assay using GRB10-knockdown cells also indicate reduced AR activity. Immunoprecipitation coupled with mass spectrometry revealed an interaction between GRB10 and the PP2A complex, which is a known phosphatase of AR. Further validations and analyses showed that GRB10 binds to the PP2Ac catalytic subunit with its PH domain. Mechanistically, GRB10 knockdown increased PP2Ac protein stability, which in turn decreased AR S81 phosphorylation and reduced AR activity. Our findings indicate a reciprocal feedback between GRB10 and AR signaling, implying the importance of GRB10 in PCa progression.
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Affiliation(s)
- Jun Hao
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Xinpei Ci
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Yong Wang
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Urology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Stephen Yiu Chuen Choi
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Sarah E Sullivan
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Kinesiology and Physical Education, McGill University, Quebec, Canada
| | - Hui Xue
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Rebecca Wu
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Xin Dong
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Anne M Haegert
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin C Collins
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dong Lin
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Yuzhuo Wang
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
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Zhu J, Shi L, Du G, Li L, Liu M. Upregulated SET Promotes Cell Survival Through Activating Akt/NF-κB Signal in Colorectal Carcinoma. Cancer Manag Res 2020; 12:4735-4745. [PMID: 32606964 PMCID: PMC7310974 DOI: 10.2147/cmar.s255930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
Purpose SET has been proven to be an oncogene, which promotes the initiation and progression in several kinds of malignant carcinomas. However, the expression and its functional roles in colorectal carcinoma (CRC) remained unknown. Materials and Methods CRC tissues samples, CRC cell lines and xenograft mouse tumors were used in this study. The mRNA and protein expressions were detected by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), and Western blot (WB), respectively. siRNAs were used to silence the gene expression. Cell viability, cell proliferation, colony formation, and apoptosis were measured by MTS assay, EdU incorporation assay, plated colony formation assay, and flow cytometry, respectively. Western blot was applied to evaluate the levels of Akt, p-Akt, c-Myc and cyclin D1. Xenograft mouse model was performed to observe the role of SET in vivo. Results Our results revealed that SET was up-regulated in CRC, and the expression of SET was increased with the development of CRC. SET knockdown in vitro attenuated cell proliferation activity, and increased cell apoptosis in CRC cells. Moreover, the knockdown of SET reduces tumorigenic potential in nude mice. For the mechanism, knockdown of SET promoted the dephosphorylation of Akt, followed by suppressing the translocation of NF-κB to nucleus. In addition, SET knockdown-mediated dephosphorylation of Akt downregulated the expression of c-Myc and Cyclin D1, which inhibited the cell survival in CRC. Conclusion Our results indicated that SET promoted cell survival via activating Akt/NF-κB signaling pathway in CRC, which strongly suggested that SET might be a potential therapeutic target in the colorectal carcinoma treatment.
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Affiliation(s)
- Jianjun Zhu
- Department of Medical Cellular Biology and Genetics, Shanxi Medical University, Taiyuan 030001, People's Republic of China
| | - Lihong Shi
- Department of Human Anatomy, School of Basic Medicine, Shanxi Medical University, Taiyuan 030001, People's Republic of China
| | - Genlai Du
- Department of Medical Cellular Biology and Genetics, Shanxi Medical University, Taiyuan 030001, People's Republic of China
| | - Li Li
- Department of Medical Cellular Biology and Genetics, Shanxi Medical University, Taiyuan 030001, People's Republic of China
| | - Ming Liu
- Department of Medical Cellular Biology and Genetics, Shanxi Medical University, Taiyuan 030001, People's Republic of China
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SET protein accumulation prevents cell death in head and neck squamous cell carcinoma through regulation of redox state and autophagy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:623-637. [DOI: 10.1016/j.bbamcr.2019.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 01/06/2019] [Accepted: 01/08/2019] [Indexed: 12/29/2022]
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De Palma RM, Parnham SR, Li Y, Oaks JJ, Peterson YK, Szulc ZM, Roth BM, Xing Y, Ogretmen B. The NMR-based characterization of the FTY720-SET complex reveals an alternative mechanism for the attenuation of the inhibitory SET-PP2A interaction. FASEB J 2019; 33:7647-7666. [PMID: 30917007 DOI: 10.1096/fj.201802264r] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The su(var)3-9, enhancer of zeste, trithorax (SET)/inhibitor 2 of protein phosphatase 2A (PP2A) oncoprotein binds and inhibits PP2A, composed of various isoforms of scaffolding, regulatory, and catalytic subunits. Targeting SET with a sphingolipid analog drug fingolimod (FTY720) or ceramide leads to the reactivation of tumor suppressor PP2A. However, molecular details of the SET-FTY720 or SET-ceramide, and mechanism of FTY720-dependent PP2A activation, remain unknown. Here, we report the first in solution examination of the SET-FTY720 or SET-ceramide complexes by NMR spectroscopy. FTY720-ceramide binding resulted in chemical shifts of residues residing at the N terminus of SET, preventing its dimerization or oligomerization. This then released SET from PP2ACα, resulting in PP2A activation, while monomeric SET remained associated with the B56γ. Our data also suggest that the PP2A holoenzyme, composed of PP2A-Aβ, PP2A-B56γ, and PP2ACα subunits, is selectively activated in response to the formation of the SET-FTY720 complex in A549 cells. Various PP2A-associated downstream effector proteins in the presence or absence of FTY720 were then identified by stable isotope labeling with amino cells in cell culture, including tumor suppressor nonmuscle myosin IIA. Attenuation of FTY720-SET association by point mutations of residues that are involved in FTY720 binding or dephosphorylation of SET at Serine 171, enhanced SET oligomerization and the formation of the SET-PP2A inhibitory complex, leading to resistance to FTY720-dependent PP2A activation.-De Palma, R. M., Parnham, S. R., Li, Y., Oaks, J. J., Peterson, Y. K., Szulc, Z. M., Roth, B. M., Xing, Y., Ogretmen, B. The NMR-based characterization of the FTY720-SET complex reveals an alternative mechanism for the attenuation of the inhibitory SET-PP2A interaction.
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Affiliation(s)
- Ryan M De Palma
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Stuart R Parnham
- Department of Biochemistry and Biophysics, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yitong Li
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Zdzislaw M Szulc
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Braden M Roth
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yongna Xing
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
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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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Wang W, Toran PT, Sabol R, Brown TJ, Barth BM. Epigenetics and Sphingolipid Metabolism in Health and Disease. ACTA ACUST UNITED AC 2019; 1. [PMID: 30637412 DOI: 10.31021/ijbs.20181105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Sphingolipids represent one of the major classes of bioactive lipids. Studies of sphingolipids have intensified in the past several years, revealing their roles in nearly all cell biological processes. In addition, epigenetic regulation has gained substantial interest due to its role in controlling gene expression and activity without changing the genetic code. In this review, we first introduce a brief background on sphingolipid biology, highlighting its role in pathophysiology. We then illustrate the concept of epigenetic regulation, focusing on how it affects the metabolism of sphingolipids. We further discuss the roles of bioactive sphingolipids as epigenetic regulators themselves. Overall, a better understanding of the relationship between epigenetics and sphingolipid metabolism may help to improve the development of sphingolipid-targeted therapeutics.
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Affiliation(s)
- Weiyuan Wang
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
| | - Paul T Toran
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
| | - Rachel Sabol
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
| | - Timothy J Brown
- Department of Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Brian M Barth
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
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Dunn J, Ferluga S, Sharma V, Futschik M, Hilton DA, Adams CL, Lasonder E, Hanemann CO. Proteomic analysis discovers the differential expression of novel proteins and phosphoproteins in meningioma including NEK9, HK2 and SET and deregulation of RNA metabolism. EBioMedicine 2018; 40:77-91. [PMID: 30594554 PMCID: PMC6412084 DOI: 10.1016/j.ebiom.2018.12.048] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 12/26/2022] Open
Abstract
Background Meningioma is the most frequent primary intracranial tumour. Surgical resection remains the main therapeutic option as pharmacological intervention is hampered by poor knowledge of their proteomic signature. There is an urgent need to identify new therapeutic targets and biomarkers of meningioma. Methods We performed proteomic profiling of grade I, II and III frozen meningioma specimens and three normal healthy human meninges using LC-MS/MS to analyse global proteins, enriched phosphoproteins and phosphopeptides. Differential expression and functional annotation of proteins was completed using Perseus, IPA® and DAVID. We validated differential expression of proteins and phosphoproteins by Western blot on a meningioma validation set and by immunohistochemistry. Findings We quantified 3888 proteins and 3074 phosphoproteins across all meningioma grades and normal meninges. Bioinformatics analysis revealed commonly upregulated proteins and phosphoproteins to be enriched in Gene Ontology terms associated with RNA metabolism. Validation studies confirmed significant overexpression of proteins such as EGFR and CKAP4 across all grades, as well as the aberrant activation of the downstream PI3K/AKT pathway, which seems differential between grades. Further, we validated upregulation of the total and activated phosphorylated form of the NIMA-related kinase, NEK9, involved in mitotic progression. Novel proteins identified and validated in meningioma included the nuclear proto-oncogene SET, the splicing factor SF2/ASF and the higher-grade specific protein, HK2, involved in cellular metabolism. Interpretation Overall, we generated a proteomic thesaurus of meningiomas for the identification of potential biomarkers and therapeutic targets. Fund This study was supported by Brain Tumour Research.
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Affiliation(s)
- Jemma Dunn
- Institute of Translational and Stratified Medicine, Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth Science Park, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - Sara Ferluga
- Institute of Translational and Stratified Medicine, Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth Science Park, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - Vikram Sharma
- School of Biomedical Science, Faculty of Medicine and Dentistry, University of Plymouth, Derriford Research Facility, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - Matthias Futschik
- School of Biomedical Science, Faculty of Medicine and Dentistry, University of Plymouth, Derriford Research Facility, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - David A Hilton
- Cellular and Anatomical Pathology, Plymouth Hospitals NHS Trust, Derriford Road, Plymouth PL6 8DH, UK
| | - Claire L Adams
- Institute of Translational and Stratified Medicine, Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth Science Park, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - Edwin Lasonder
- School of Biomedical Science, Faculty of Medicine and Dentistry, University of Plymouth, Derriford Research Facility, Research Way, Derriford, Plymouth PL6 8BU, UK
| | - C Oliver Hanemann
- Institute of Translational and Stratified Medicine, Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth Science Park, Research Way, Derriford, Plymouth PL6 8BU, UK.
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Williams AP, Garner EF, Waters AM, Stafman LL, Aye JM, Markert H, Stewart JE, Beierle EA. Investigation of PP2A and Its Endogenous Inhibitors in Neuroblastoma Cell Survival and Tumor Growth. Transl Oncol 2018; 12:84-95. [PMID: 30286326 PMCID: PMC6169101 DOI: 10.1016/j.tranon.2018.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 12/22/2022] Open
Abstract
High-risk neuroblastoma continues to carry a poor prognosis. Nearly 50% of these tumors relapse following extensive treatment regimens. Protein phosphatase 2A (PP2A), a tumor suppressor, has been shown to be downregulated in many human cancers via multiple mechanisms including upregulation of its endogenous inhibitors, I2PP2A or CIP2A. We hypothesized that inhibition of the endogenous PP2A inhibitors or activation of PP2A would decrease tumorigenicity in human neuroblastoma cells. Four human neuroblastoma cell lines were utilized. Expression of PP2A and its endogenous inhibitors I2PP2A and CIP2A was confirmed by immunoblotting. PP2A activation was measured via phosphatase activation assay. Multiple parallel methods including siRNA inhibition of the endogenous PP2A inhibitors and pharmacologic activation of PP2A were utilized. Cell viability, proliferation, migration, and invasion assays were performed. In vivo studies were utilized to determine the effects of PP2A activation on neuroblastoma tumor growth. Inhibition of the endogenous inhibitors of PP2A or pharmacologic activation of PP2A with the PP2A activator FTY720 led to decreased neuroblastoma cell viability, proliferation, migration, and invasion. Treatment of mice bearing SK-N-AS or SK-N-BE(2) neuroblastoma tumors with FTY720 resulted in a significant decrease in tumor growth compared to vehicle-treated animals. In conclusion, activation of PP2A may provide a novel therapeutic target for neuroblastoma.
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Affiliation(s)
- Adele P Williams
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Evan F Garner
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Alicia M Waters
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Laura L Stafman
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Jamie M Aye
- Division of Hematology and Oncology Department of Pediatrics, University of Alabama, Birmingham, Birmingham, AL
| | - Hooper Markert
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Jerry E Stewart
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL
| | - Elizabeth A Beierle
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL.
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11
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Lu W, Chen Z, Ren X, Liu W, Deng R, Yuan J, Huang X, Zhu W, Liu J. SET promotes H2Ak9 acetylation by suppressing HDAC1 in trichloroethylene-induced hepatic cytotoxicity. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 59:125-131. [PMID: 29579541 DOI: 10.1016/j.etap.2018.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Trichloroethylene (TCE) was widely used as an industrial solvent which could cause severe liver damage. The histone chaperone SET have been identified as an important mediator of TCE-induced hepatic cytotoxicity in our previous study; however, the underlying regulatory mechanisms remain poorly understood. In this study, we found a total of 136 histone acetylation sites involved in TCE-induced hepatic cytotoxicity with the technique of Triton-acid-urea polyacrylamide gel electrophoresis (TAU-PAGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Importantly, 17 histone acetylation sites were revealed to be mediated by SET in TCE-induced cytotoxicity. The acetylation of histone H2AK9 (H2AK9ac) was further validated by Western-blot analysis. The data showed that TCE treatment increased the acetylation of H2AK9 in hepatic L-02 cell and decreased the one in SET-knockdown L-02 cells. Besides, levels of the histone deacetylases (HDACs, including HDAC1, HDAC2, and HDAC3) was also analyzed. Interestingly, the level of HDAC1 was aberrantly suppressed in TCE-treated L-02 cells while enhanced in SET-knockdown L-02 cells. To further explore the potential role of HDAC1 in SET-mediated hepatic cytotoxicity of TCE, we employed RNA interference (RNAi) to knockdown HDAC1 in both wide type L-02 and SET-knockdown cells. The results showed that the siRNA inhibition of HDAC1 increased the acetylation of H2AK9. Taken together, our data suggested that SET promoted the acetylation of H2AK9 via suppressing the level of HDAC1, which was involved in SET-mediated hepatic cytotoxicity of TCE.
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Affiliation(s)
- Weixue Lu
- School of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China; Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Zhihong Chen
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China; School of Public Health, Southern Medical University, Tonghe District, Guangzhou, 510515, China
| | - Xiaohu Ren
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Wei Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Rongxia Deng
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Jianhui Yuan
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Xinfeng Huang
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Weiguo Zhu
- School of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China; School of Materials Science and Engineering, Jiangsu Collaboration Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Wujin District, Changzhou 213164, China.
| | - Jianjun Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China.
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12
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Mukhopadhyay A, Hanold LE, Thayele Purayil H, Gisemba SA, Senadheera SN, Aldrich JV. Macrocyclic peptides decrease c-Myc protein levels and reduce prostate cancer cell growth. Cancer Biol Ther 2017; 18:571-583. [PMID: 28692379 PMCID: PMC5652972 DOI: 10.1080/15384047.2017.1345384] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 04/26/2017] [Accepted: 06/17/2017] [Indexed: 10/19/2022] Open
Abstract
The oncoprotein c-Myc is often overexpressed in cancer cells, and the stability of this protein has major significance in deciding the fate of a cell. Thus, targeting c-Myc levels is an attractive approach for developing therapeutic agents for cancer treatment. In this study, we report the anti-cancer activity of the macrocyclic peptides [D-Trp]CJ-15,208 (cyclo[Phe-D-Pro-Phe-D-Trp]) and the natural product CJ-15,208 (cyclo[Phe-D-Pro-Phe-Trp]). [D-Trp]CJ-15,208 reduced c-Myc protein levels in prostate cancer cells and decreased cell proliferation with IC50 values ranging from 2.0 to 16 µM in multiple PC cell lines. [D-Trp]CJ-15,208 induced early and late apoptosis in PC-3 cells following 48 hours treatment, and growth arrest in the G2 cell cycle phase following both 24 and 48 hours treatment. Down regulation of c-Myc in PC-3 cells resulted in loss of sensitivity to [D-Trp]CJ-15,208 treatment, while overexpression of c-Myc in HEK-293 cells imparted sensitivity of these cells to [D-Trp]CJ-15,208 treatment. This macrocyclic tetrapeptide also regulated PP2A by reducing the levels of its phosphorylated form which regulates the stability of cellular c-Myc protein. Thus [D-Trp]CJ-15,208 represents a new lead compound for the potential development of an effective treatment of prostate cancer.
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Affiliation(s)
- Archana Mukhopadhyay
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas, USA
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida, USA
| | - Laura E. Hanold
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida, USA
| | - Hamsa Thayele Purayil
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, Florida, USA
| | - Solomon A. Gisemba
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas, USA
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida, USA
| | | | - Jane V. Aldrich
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas, USA
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida, USA
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13
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He K, Shi L, Jiang T, Li Q, Chen Y, Meng C. Association between SET expression and glioblastoma cell apoptosis and proliferation. Oncol Lett 2016; 12:2435-2444. [PMID: 27698810 PMCID: PMC5038217 DOI: 10.3892/ol.2016.4951] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/01/2016] [Indexed: 02/05/2023] Open
Abstract
Glioblastoma multiforme (GBM) was one of the first cancer types systematically studied at a genomic and transcriptomic level due to its high incidence and aggressivity; however, the detailed mechanism remains unclear, even though it is known that numerous cytokines are involved in the occurrence and development of GBM. The present study aimed to determine whether the SET gene has a role in human glioblastoma carcinogenesis. A total of 32 samples, including 18 cases of glioma, 2 cases of meningioma and 12 normal brain tissue samples, were detected using the streptavidin-peroxidase method through immunohistochemistry. To reduce SET gene expression in U251 and U87MG cell lines, the RNA interference technique was used and transfection with small interfering (si)RNA of the SET gene was performed. Cell apoptosis was detected by flow cytometry, cell migration was examined by Transwell migration assay and cell proliferation was determined by Cell Counting Kit-8. SET, Bcl-2, Bax and caspase-3 mRNA and protein expression levels were detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Positive protein expression of SET was observed in the cell nucleus, with the expression level of SET significantly higher in glioma tissues compared with normal brain tissue (P=0.001). Elevated expression of SET was significantly associated with gender (P=0.002), tumors classified as World Health Organization grade II (P=0.031), III (P=0.003) or IV (P=0.001), and moderately (P=0.031) or poorly differentiated (P=0.001) tumors. Compared with the negative and non-treatment (blank) control cells, SET gene expression was significantly inhibited (P=0.006 and P<0.001), cell apoptosis was significantly increased (P=0.001 and P<0.001), cell proliferation was significantly inhibited (P=0.002 and P=0.015), and cell migration was significantly decreased (P=0.001 and P=0.001) in siRNA-transfected U87MG−SET and U251−SET cells, respectively. In addition, mRNA and protein expression levels of Bcl-2 were significantly inhibited in U87MG−SET and U251−SET cells, while mRNA and protein expression levels of Bax and caspase-3 were significantly increased, compared with the two control groups. Thus, the current data suggests that SET may regulate the proliferation and apoptosis of glioblastoma cells by upregulating Bcl-2, and downregulating Bax and caspase-3.
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Affiliation(s)
- Kunyan He
- Department of Anatomy, Basic Medical and Forensic Medical Institute, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lihong Shi
- Department of Anatomy, Basic Medical and Forensic Medical Institute, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Tingting Jiang
- Department of Anatomy, Basic Medical and Forensic Medical Institute, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Qiang Li
- Department of Neurosurgery, The Third People's Hospital of Chengdu, Chengdu, Sichuan 610041, P.R. China
| | - Yao Chen
- Department of Anatomy, Basic Medical and Forensic Medical Institute, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Chuan Meng
- Department of Neurosurgery, The Third People's Hospital of Chengdu, Chengdu, Sichuan 610041, P.R. China
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Cristóbal I, Madoz-Gúrpide J, Manso R, González-Alonso P, Rojo F, García-Foncillas J. Potential anti-tumor effects of FTY720 associated with PP2A activation: a brief review. Curr Med Res Opin 2016; 32:1137-41. [PMID: 26950691 DOI: 10.1185/03007995.2016.1162774] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
FTY720 (Fingolimod, Gilenya (†) ) is an FDA-approved immunosuppressant currently used in the treatment of multiple sclerosis. However, a large number of studies over the last few years have shown that FTY720 shows potent antitumor properties that suggest its potential usefulness as a novel anticancer agent. Interestingly, the restoration of protein phosphatase 2A (PP2A) activity mediated by FTY720 could play a key role in its antitumor effects. Taking into account that PP2A inactivation is a common event that determines poor outcome in several tumor types, FTY720 could serve as an alternative therapeutic strategy for cancer patients with such alterations.
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Affiliation(s)
- Ion Cristóbal
- a Translational Oncology Division , Oncohealth Institute, IIS-Fundacion Jimenez Diaz-UAM, University Hospital 'Fundacion Jimenez Diaz' , Madrid , Spain
| | | | - Rebeca Manso
- b Pathology Department , IIS 'Fundacion Jimenez Diaz' , Madrid , Spain
| | | | - Federico Rojo
- b Pathology Department , IIS 'Fundacion Jimenez Diaz' , Madrid , Spain
| | - Jesús García-Foncillas
- a Translational Oncology Division , Oncohealth Institute, IIS-Fundacion Jimenez Diaz-UAM, University Hospital 'Fundacion Jimenez Diaz' , Madrid , Spain
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15
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Schrecengost RS, Keller SN, Schiewer MJ, Knudsen KE, Smith CD. Downregulation of Critical Oncogenes by the Selective SK2 Inhibitor ABC294640 Hinders Prostate Cancer Progression. Mol Cancer Res 2015; 13:1591-601. [PMID: 26271487 DOI: 10.1158/1541-7786.mcr-14-0626] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 07/30/2015] [Indexed: 12/12/2022]
Abstract
UNLABELLED The bioactive sphingolipid sphingosine-1-phosphate (S1P) drives several hallmark processes of cancer, making the enzymes that synthesize S1P, that is, sphingosine kinase 1 and 2 (SK1 and SK2), important molecular targets for cancer drug development. ABC294640 is a first-in-class SK2 small-molecule inhibitor that effectively inhibits cancer cell growth in vitro and in vivo. Given that AR and Myc are two of the most widely implicated oncogenes in prostate cancer, and that sphingolipids affect signaling by both proteins, the therapeutic potential for using ABC294640 in the treatment of prostate cancer was evaluated. This study demonstrates that ABC294640 abrogates signaling pathways requisite for prostate cancer growth and proliferation. Key findings validate that ABC294640 treatment of early-stage and advanced prostate cancer models downregulate Myc and AR expression and activity. This corresponds with significant inhibition of growth, proliferation, and cell-cycle progression. Finally, oral administration of ABC294640 was found to dramatically impede xenograft tumor growth. Together, these pre-clinical findings support the hypotheses that SK2 activity is required for prostate cancer function and that ABC294640 represents a new pharmacological agent for treatment of early stage and aggressive prostate cancer. IMPLICATIONS Sphingosine kinase inhibition disrupts multiple oncogenic signaling pathways that are deregulated in prostate cancer.
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Affiliation(s)
| | - Staci N Keller
- Apogee Biotechnology Corporation, Hummelstown, Pennsylvania
| | - Matthew J Schiewer
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Karen E Knudsen
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania. Department of Urology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania. Department of Radiation Oncology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Charles D Smith
- Apogee Biotechnology Corporation, Hummelstown, Pennsylvania.
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16
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González-Alonso P, Cristóbal I, Manso R, Madoz-Gúrpide J, García-Foncillas J, Rojo F. PP2A inhibition as a novel therapeutic target in castration-resistant prostate cancer. Tumour Biol 2015; 36:5753-5. [DOI: 10.1007/s13277-015-3849-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 07/24/2015] [Indexed: 12/18/2022] Open
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Dany M, Ogretmen B. Ceramide induced mitophagy and tumor suppression. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2834-45. [PMID: 25634657 DOI: 10.1016/j.bbamcr.2014.12.039] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/09/2014] [Accepted: 12/25/2014] [Indexed: 12/11/2022]
Abstract
Sphingolipids are bioactive lipid effectors, which are involved in the regulation of various cellular signaling pathways. Sphingolipids play essential roles in controlling cell inflammation, proliferation, death, migration, senescence, metastasis and autophagy. Alterations in sphingolipid metabolism have been also implicated in many human cancers. Macroautophagy (referred to here as autophagy) is a form of nonselective sequestering of cytosolic materials by double membrane structures, autophagosomes, which can be either protective or lethal for cells. Ceramide, a central molecule of sphingolipid metabolism is involved in the regulation of autophagy at various levels, including the induction of lethal mitophagy, a selective autophagy process to target and eliminate damaged mitochondria. In this review, we focused on recent studies with regard to the regulation of autophagy, in particular lethal mitophagy, by ceramide, and aimed at providing discussion points for various context-dependent roles and mechanisms of action of ceramide in controlling mitophagy.
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Affiliation(s)
- Mohammed Dany
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas Street, Charleston, SC 29425, USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas Street, Charleston, SC 29425, USA.
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Oaks J, Ogretmen B. Regulation of PP2A by Sphingolipid Metabolism and Signaling. Front Oncol 2015; 4:388. [PMID: 25642418 PMCID: PMC4295541 DOI: 10.3389/fonc.2014.00388] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 12/27/2014] [Indexed: 12/21/2022] Open
Abstract
Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase that is a primary regulator of cellular proliferation through targeting of proliferative kinases, cell cycle regulators, and apoptosis inhibitors. It is through the regulation of these regulatory elements that gives PP2A tumor suppressor functions. In addition to mutations on the regulatory subunits, the phosphatase/tumor suppressing activity of PP2A is also inhibited in several cancer types due to overexpression or modification of the endogenous PP2A inhibitors such as SET/I2PP2A. This review focuses on the current literature regarding the interactions between the lipid signaling molecules, selectively sphingolipids, and the PP2A inhibitor SET for the regulation of PP2A, and the therapeutic potential of sphingolipids as PP2A activators for tumor suppression via targeting SET oncoprotein.
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Affiliation(s)
- Joshua Oaks
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina , Charleston, SC , USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina , Charleston, SC , USA
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Cristóbal I, Rincón R, Manso R, Caramés C, Zazo S, Madoz-Gúrpide J, Rojo F, García-Foncillas J. Deregulation of the PP2A inhibitor SET shows promising therapeutic implications and determines poor clinical outcome in patients with metastatic colorectal cancer. Clin Cancer Res 2014; 21:347-56. [PMID: 25388166 DOI: 10.1158/1078-0432.ccr-14-0724] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE SET is an endogenous PP2A inhibitor that might represent a novel molecular target for antitumor therapy. The aim of this study was to evaluate the molecular effects of SET deregulation and its potential clinical significance in metastatic colorectal cancer (mCRC). EXPERIMENTAL DESIGN We studied the biologic effects of SET on cell growth, colonosphere formation, caspase activity, PP2A activation status, and sensitivity to oxaliplatin and FTY720 treatments. Moreover, we analyzed SET expression by immunostaining in 242 patients with mCRC. RESULTS SET deregulation promotes cell growth and colonosphere formation and inhibits PP2A, thereby impairing its antitumor effects. Moreover, SET reduces sensitivity to oxaliplatin in colorectal cancer cell lines, which is restored after FTY720 treatment. SET overexpression was detected in 24.8% (60 of 242) of patients with mCRC and determined significantly shorter overall (8.6 vs. 27 months; P < 0.001) and progression-free survival (7.1 vs. 13.7 months; P < 0.001), and poor response to oxaliplatin-based chemotherapy (P = 0.004). Interestingly, its prognostic value was particularly evident in patients younger than 70 years and in those harboring KRAS mutations. CONCLUSIONS SET overexpression is a frequent event in mCRC that plays a potential oncogenic role associated with worse outcome and resistance to oxaliplatin. Moreover, this alteration defines a subgroup of patients who could benefit from therapies containing PP2A activators such as FTY720.
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Affiliation(s)
- Ion Cristóbal
- Translational Oncology Division, Oncohealth institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz," Madrid, Spain
| | - Raúl Rincón
- Translational Oncology Division, Oncohealth institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz," Madrid, Spain
| | - Rebeca Manso
- Pathology Department, IIS "Fundación Jiménez Diaz," UAM, Madrid, Spain
| | - Cristina Caramés
- Translational Oncology Division, Oncohealth institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz," Madrid, Spain
| | - Sandra Zazo
- Pathology Department, IIS "Fundación Jiménez Diaz," UAM, Madrid, Spain
| | | | - Federico Rojo
- Pathology Department, IIS "Fundación Jiménez Diaz," UAM, Madrid, Spain.
| | - Jesús García-Foncillas
- Translational Oncology Division, Oncohealth institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz," Madrid, Spain.
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20
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Liu H, Gu Y, Yin J, Zheng G, Wang C, Zhang Z, Deng M, Liu J, Jia X, He Z. SET-mediated NDRG1 inhibition is involved in acquisition of epithelial-to-mesenchymal transition phenotype and cisplatin resistance in human lung cancer cell. Cell Signal 2014; 26:2710-20. [PMID: 25152373 DOI: 10.1016/j.cellsig.2014.08.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/15/2014] [Indexed: 12/22/2022]
Abstract
Development of resistance to therapy continues to be a serious clinical problem in lung cancer management. Cancer cells undergoing epithelial-to-mesenchymal transition (EMT) have been shown to play roles in resistance to chemotherapy. Here, we utilized a proteomics-based method and identified a significant downregulation of the metastasis suppressor NDRG1 in drug resistant lung cancer cells. We showed that downregulation of DNRG1 constitutes a mechanism for acquisition of EMT phenotype and endows lung cancer cells with an increased resistance to cisplatin. We also identified a signal cascade, namely, SET--| PP2A--| c-myc--| NDRG1, in which upregulation of SET is critical for inhibition of NDRG1. We also found that blockade of SET (or reactivation of PP2A) by FTY720 reverted EMT, restored drug sensitivity, and inhibited invasiveness and growth of lung tumor xenografts. Together, our results indicated a functional link between SET-mediated NDRG1 regulation and acquisition of EMT phenotype and drug resistance, and provided an evidence that blockade of SET-driven EMT can overcome drug resistance and inhibit tumor progression.
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Affiliation(s)
- Hao Liu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Yixue Gu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Jiang Yin
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Guopei Zheng
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Chenkun Wang
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Zhijie Zhang
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Min Deng
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Jifang Liu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Xiaoting Jia
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Zhimin He
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, China.
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Abstract
The nomenclature for the serine/threonine protein phosphatases was established by Professor Sir Philip Cohen over 30 years ago. (1) At that time protein phosphatase 1 was known to have two small inhibitory proteins (I-1 and I-2) and be regulated by sub-cellular location whereas no protein inhibitor had yet been discovered for the related multi-subunit phosphatase PP2A. That paradigm subsequently changed, and several PP2A protein inhibitors have been discovered. (2) The protein I2PP2A (SET) is considered to be oncogenic, i.e., PP2A is a tumor suppressor, and is overexpressed in many tumor cell types (ref. 3, and refs. therein). I2PP2A also has other targets besides PP2A, e.g., DNA exonucleases and modification of histone acetylation. (4) PP2A activity is known to be regulated by the bioactive lipid ceramide, and this occurs through both I2PP2A inhibition and PP2A de-repression and through ceramide actions on subunits of the PP2A enzyme complex. (5)(,) (6) In the present manuscript the authors examined the expression of I2PP2A in prostate cancer and prostate epithelial cells. They determined whether ceramide could decrease accumulation of the oncogene c-Myc through inhibition of I2PP2A and activation of PP2A. As I2PP2A is also an inhibitor of histone acetylation they determined whether ceramide could block the epigenetic action of I2PP2A.
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Affiliation(s)
- Paul Dent
- Department of Neurosurgery; Massey Cancer Center; Virginia Commonwealth University; Richmond, VA USA
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