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Tinsley SL, Shelley RA, Mall GK, Chianis ERD, Dhiman A, Baral G, Kothandaraman H, Thoma MC, Daniel CJ, Lanman NA, Pasca di Magliano M, Narla G, Solorio L, Dykhuizen EC, Sears RC, Allen-Petersen BL. KRAS-mediated upregulation of CIP2A promotes suppression of PP2A-B56α to initiate pancreatic cancer development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.01.547283. [PMID: 38826439 PMCID: PMC11142131 DOI: 10.1101/2023.07.01.547283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Oncogenic mutations in KRAS are present in approximately 95% of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) and are considered the initiating event of pancreatic intraepithelial neoplasia (PanIN) precursor lesions. While it is well established that KRAS mutations drive the activation of oncogenic kinase cascades during pancreatic oncogenesis, the effects of oncogenic KRAS signaling on regulation of phosphatases during this process is not fully appreciated. Protein Phosphatase 2A (PP2A) has been implicated in suppressing KRAS-driven cellular transformation. However, low PP2A activity is observed in PDAC cells compared to non-transformed cells, suggesting that suppression of PP2A activity is an important step in the overall development of PDAC. In the current study, we demonstrate that KRAS G12D induces the expression of both an endogenous inhibitor of PP2A activity, Cancerous Inhibitor of PP2A (CIP2A), and the PP2A substrate, c-MYC. Consistent with these findings, KRAS G12D sequestered the specific PP2A subunit responsible for c-MYC degradation, B56α, away from the active PP2A holoenzyme in a CIP2A-dependent manner. During PDAC initiation in vivo , knockout of B56α promoted KRAS G12D tumorigenesis by accelerating acinar-to-ductal metaplasia (ADM) and the formation of PanIN lesions. The process of ADM was attenuated ex vivo in response to pharmacological re-activation of PP2A utilizing direct small molecule activators of PP2A (SMAPs). Together, our results suggest that suppression of PP2A-B56α through KRAS signaling can promote the MYC-driven initiation of pancreatic tumorigenesis.
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Rasool RU, O'Connor CM, Das CK, Alhusayan M, Verma BK, Islam S, Frohner IE, Deng Q, Mitchell-Velasquez E, Sangodkar J, Ahmed A, Linauer S, Mudrak I, Rainey J, Zawacki KP, Suhan TK, Callahan CG, Rebernick R, Natesan R, Siddiqui J, Sauter G, Thomas D, Wang S, Taylor DJ, Simon R, Cieslik M, Chinnaiyan AM, Busino L, Ogris E, Narla G, Asangani IA. Loss of LCMT1 and biased protein phosphatase 2A heterotrimerization drive prostate cancer progression and therapy resistance. Nat Commun 2023; 14:5253. [PMID: 37644036 PMCID: PMC10465527 DOI: 10.1038/s41467-023-40760-6] [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: 01/03/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023] Open
Abstract
Loss of the tumor suppressive activity of the protein phosphatase 2A (PP2A) is associated with cancer, but the underlying molecular mechanisms are unclear. PP2A holoenzyme comprises a heterodimeric core, a scaffolding A subunit and a catalytic C subunit, and one of over 20 distinct substrate-directing regulatory B subunits. Methylation of the C subunit regulates PP2A heterotrimerization, affecting B subunit binding and substrate specificity. Here, we report that the leucine carboxy methyltransferase (LCMT1), which methylates the L309 residue of the C subunit, acts as a suppressor of androgen receptor (AR) addicted prostate cancer (PCa). Decreased methyl-PP2A-C levels in prostate tumors is associated with biochemical recurrence and metastasis. Silencing LCMT1 increases AR activity and promotes castration-resistant prostate cancer growth. LCMT1-dependent methyl-sensitive AB56αCme heterotrimers target AR and its critical coactivator MED1 for dephosphorylation, resulting in the eviction of the AR-MED1 complex from chromatin and loss of target gene expression. Mechanistically, LCMT1 is regulated by S6K1-mediated phosphorylation-induced degradation requiring the β-TRCP, leading to acquired resistance to anti-androgens. Finally, feedforward stabilization of LCMT1 by small molecule activator of phosphatase (SMAP) results in attenuation of AR-signaling and tumor growth inhibition in anti-androgen refractory PCa. These findings highlight methyl-PP2A-C as a prognostic marker and that the loss of LCMT1 is a major determinant in AR-addicted PCa, suggesting therapeutic potential for AR degraders or PP2A modulators in prostate cancer treatment.
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Affiliation(s)
- Reyaz Ur Rasool
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Caitlin M O'Connor
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Chandan Kanta Das
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Mohammed Alhusayan
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Brijesh Kumar Verma
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Sehbanul Islam
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Ingrid E Frohner
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna, 1030, Austria
| | - Qu Deng
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Erick Mitchell-Velasquez
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Jaya Sangodkar
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Aqila Ahmed
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Sarah Linauer
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna, 1030, Austria
| | - Ingrid Mudrak
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna, 1030, Austria
| | - Jessica Rainey
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Kaitlin P Zawacki
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Tahra K Suhan
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Catherine G Callahan
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ryan Rebernick
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Ramakrishnan Natesan
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Javed Siddiqui
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Guido Sauter
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Dafydd Thomas
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Shaomeng Wang
- Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Derek J Taylor
- Department of Biochemistry Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Ronald Simon
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Marcin Cieslik
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Arul M Chinnaiyan
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Luca Busino
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA
| | - Egon Ogris
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna, 1030, Austria.
| | - Goutham Narla
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, USA.
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Irfan A Asangani
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA, 19104, USA.
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 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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Aakula A, Sharma M, Tabaro F, Nätkin R, Kamila J, Honkanen H, Schapira M, Arrowsmith C, Nykter M, Westermarck J. RAS and PP2A activities converge on epigenetic gene regulation. Life Sci Alliance 2023; 6:e202301928. [PMID: 36858798 PMCID: PMC9979842 DOI: 10.26508/lsa.202301928] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 03/03/2023] Open
Abstract
RAS-mediated human cell transformation requires inhibition of the tumor suppressor protein phosphatase 2A (PP2A). However, the phosphoprotein targets and cellular processes in which RAS and PP2A activities converge in human cancers have not been systematically analyzed. Here, we discover that phosphosites co-regulated by RAS and PP2A are enriched on proteins involved in epigenetic gene regulation. As examples, RAS and PP2A co-regulate the same phosphorylation sites on HDAC1/2, KDM1A, MTA1/2, RNF168, and TP53BP1. We validate RAS- and PP2A-elicited regulation of HDAC1/2 chromatin recruitment, of RNF168-TP53BP1 interaction, and of gene expression. Consistent with their known synergistic effects in cancer, RAS activation and PP2A inhibition resulted in epigenetic reporter derepression and activation of oncogenic transcription. Transcriptional derepression by PP2A inhibition was associated with an increase in euchromatin and a decrease in global DNA methylation. Collectively, the results indicate that epigenetic protein complexes constitute a significant point of convergence for RAS hyperactivity and PP2A inhibition in cancer. Furthermore, the work provides an important resource for future studies focusing on phosphoregulation of epigenetic gene regulation in cancer and in other RAS/PP2A-regulated cellular processes.
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Affiliation(s)
- Anna Aakula
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Mukund Sharma
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Francesco Tabaro
- Laboratory of Computational Biology, Faculty of Medicine and Health Technology, Tampere University and Tays Cancer Centre, Tampere, Finland
| | - Reetta Nätkin
- Laboratory of Computational Biology, Faculty of Medicine and Health Technology, Tampere University and Tays Cancer Centre, Tampere, Finland
| | - Jesse Kamila
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Henrik Honkanen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Matthieu Schapira
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
| | - Cheryl Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Matti Nykter
- Laboratory of Computational Biology, Faculty of Medicine and Health Technology, Tampere University and Tays Cancer Centre, Tampere, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, Finland
| | - Jukka Westermarck
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
- Institute of Biomedicine, University of Turku, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland
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5
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Randhawa PK, Rajakumar A, Futuro de Lima IB, Gupta MK. Eugenol attenuates ischemia-mediated oxidative stress in cardiomyocytes via acetylation of histone at H3K27. Free Radic Biol Med 2023; 194:326-336. [PMID: 36526244 PMCID: PMC10074330 DOI: 10.1016/j.freeradbiomed.2022.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022]
Abstract
Despite clinical advances, ischemia-induced cardiac diseases remain an underlying cause of death worldwide. Epigenetic modifications, especially alterations in the acetylation of histone proteins play a pivotal role in counteracting stressful conditions, including ischemia. In our study, we found that histone active mark H3K27ac was significantly reduced and histone repressive mark H3K27me3 was significantly upregulated in the cardiomyocytes exposed to the ischemic condition. Then, we performed a high throughput drug screening assay using rat ventricular cardiomyocytes during the ischemic condition and screened an antioxidant compound library comprising of 84 drugs for H3K27ac by fluorescence microscopy. Our data revealed that most of the phenolic compounds like eugenol, apigenin, resveratrol, bis-demethoxy curcumin, D-gamma-tocopherol, ambroxol, and non-phenolic compounds like l-Ergothioneine, ciclopirox ethanolamine, and Tanshinone IIA have a crucial role in maintaining the cellular H3K27ac histone marks during the ischemic condition. Further, we tested the role of eugenol on cellular protection during ischemia. Our study shows that ischemia significantly reduces cellular viability and increases total reactive oxygen species (ROS), and mitochondrial ROS in the cells. Interestingly, eugenol treatment significantly restores the cellular acetylation at H3K27, decreases cellular ROS, and improves cellular viability. To explore the mechanism of eugenol-medicated inhibition of deacetylation, we performed a RNAseq experiment. Analysis of transcriptome data using IPA indicated that eugenol regulates several cellular functions associated with cardiovascular diseases, and metabolic processes. Further, we found that eugenol regulates the expression of HMGN1, CD151 and Ppp2ca genes during ischemia. Furthermore, we found that eugenol might protect the cells from ischemia through modulation of HMGN1 protein expression, which plays an active role in regulation of histone acetylation and cellular protection during stress. Thus, our study indicated that eugenol can be exploited as an agent to protect the ischemic cells and also could be used to develop a novel drug for treating cardiac disease.
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Affiliation(s)
- Puneet Kaur Randhawa
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA
| | - Aishwarya Rajakumar
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA
| | - Isabela Beatriz Futuro de Lima
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA
| | - Manish K Gupta
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA.
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Nussinov R, Tsai CJ, Jang H. A New View of Activating Mutations in Cancer. Cancer Res 2022; 82:4114-4123. [PMID: 36069825 PMCID: PMC9664134 DOI: 10.1158/0008-5472.can-22-2125] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/16/2022] [Accepted: 09/01/2022] [Indexed: 12/14/2022]
Abstract
A vast effort has been invested in the identification of driver mutations of cancer. However, recent studies and observations call into question whether the activating mutations or the signal strength are the major determinant of tumor development. The data argue that signal strength determines cell fate, not the mutation that initiated it. In addition to activating mutations, factors that can impact signaling strength include (i) homeostatic mechanisms that can block or enhance the signal, (ii) the types and locations of additional mutations, and (iii) the expression levels of specific isoforms of genes and regulators of proteins in the pathway. Because signal levels are largely decided by chromatin structure, they vary across cell types, states, and time windows. A strong activating mutation can be restricted by low expression, whereas a weaker mutation can be strengthened by high expression. Strong signals can be associated with cell proliferation, but too strong a signal may result in oncogene-induced senescence. Beyond cancer, moderate signal strength in embryonic neural cells may be associated with neurodevelopmental disorders, and moderate signals in aging may be associated with neurodegenerative diseases, like Alzheimer's disease. The challenge for improving patient outcomes therefore lies in determining signaling thresholds and predicting signal strength.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation Laboratory, NCI, Frederick, Maryland
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation Laboratory, NCI, Frederick, Maryland
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation Laboratory, NCI, Frederick, Maryland
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7
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Novel epigenetic therapeutic strategies and targets in cancer. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166552. [PMID: 36126898 DOI: 10.1016/j.bbadis.2022.166552] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022]
Abstract
The critical role of dysregulated epigenetic pathways in cancer genesis, development, and therapy has typically been established as a result of scientific and technical innovations in next generation sequencing. RNA interference, histone modification, DNA methylation and chromatin remodelling are epigenetic processes that control gene expression without causing mutations in the DNA. Although epigenetic abnormalities are thought to be a symptom of cell tumorigenesis and malignant events that impact tumor growth and drug resistance, physicians believe that related processes might be a key therapeutic target for cancer treatment and prevention due to the reversible nature of these processes. A plethora of novel strategies for addressing epigenetics in cancer therapy for immuno-oncological complications are currently available - ranging from basic treatment to epigenetic editing. - and they will be the subject of this comprehensive review. In this review, we cover most of the advancements made in the field of targeting epigenetics with special emphasis on microbiology, plasma science, biophysics, pharmacology, molecular biology, phytochemistry, and nanoscience.
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8
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Poudel G, Tolland MG, Hughes TP, Pagani IS. Mechanisms of Resistance and Implications for Treatment Strategies in Chronic Myeloid Leukaemia. Cancers (Basel) 2022; 14:cancers14143300. [PMID: 35884363 PMCID: PMC9317051 DOI: 10.3390/cancers14143300] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/28/2022] [Accepted: 07/04/2022] [Indexed: 12/01/2022] Open
Abstract
Simple Summary Chronic myeloid leukaemia (CML) is a type of blood cancer that is currently well-managed with drugs that target cancer-causing proteins. However, a significant proportion of CML patients do not respond to those drug treatments or relapse when they stop those drugs because the cancer cells in those patients stop relying on that protein and instead develop a new way to survive. Therefore, new treatment strategies may be necessary for those patients. In this review, we discuss those additional survival pathways and outline combination treatment strategies to increase responses and clinical outcomes, improving the lives of CML patients. Abstract Tyrosine kinase inhibitors (TKIs) have revolutionised the management of chronic myeloid leukaemia (CML), with the disease now having a five-year survival rate over 80%. The primary focus in the treatment of CML has been on improving the specificity and potency of TKIs to inhibit the activation of the BCR::ABL1 kinase and/or overcoming resistance driven by mutations in the BCR::ABL1 oncogene. However, this approach may be limited in a significant proportion of patients who develop TKI resistance despite the effective inhibition of BCR::ABL1. These patients may require novel therapeutic strategies that target both BCR::ABL1-dependent and BCR::ABL1-independent mechanisms of resistance. The combination treatment strategies that target alternative survival signalling, which may contribute towards BCR::ABL1-independent resistance, could be a successful strategy for eradicating residual leukaemic cells and consequently increasing the response rate in CML patients.
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Affiliation(s)
- Govinda Poudel
- Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia; (G.P.); (M.G.T.); (T.P.H.)
- School of Medicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia
- Australasian Leukaemia and Lymphoma Group, Richmond, VIC 3121, Australia
| | - Molly G. Tolland
- Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia; (G.P.); (M.G.T.); (T.P.H.)
- School of Medicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia
| | - Timothy P. Hughes
- Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia; (G.P.); (M.G.T.); (T.P.H.)
- School of Medicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia
- Australasian Leukaemia and Lymphoma Group, Richmond, VIC 3121, Australia
- Department of Haematology and Bone Marrow Transplantation, Royal Adelaide Hospital and SA Pathology, Adelaide, SA 5000, Australia
| | - Ilaria S. Pagani
- Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia; (G.P.); (M.G.T.); (T.P.H.)
- School of Medicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia
- Australasian Leukaemia and Lymphoma Group, Richmond, VIC 3121, Australia
- Correspondence:
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9
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Do HA, Baek KH. Protein phosphatase 2A regulated by USP7 is polyubiquitinated and polyneddylated. Oncol Rep 2022; 48:124. [PMID: 35593311 DOI: 10.3892/or.2022.8335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/14/2022] [Indexed: 11/05/2022] Open
Abstract
Ubiquitin‑specific protease 7 (USP7) participates in the ubiquitin‑proteasome system (UPS), and is considered an essential regulator of substrate stability in cancers. In a previous study, the substrates that bind to USP7 were separated through two‑dimensional electrophoresis (2‑DE), which resulted in the identification of protein phosphatase 2A (PP2A) through matrix‑assisted laser desorption‑ionization time‑of‑flight mass spectrometry (MALDI‑TOF/MS) analysis. In the present study, GST pull‑down assay was performed to determine whether USP7 and PP2A directly bind to each other. Immunocytochemistry assay confirmed that USP7 co‑localizes with PP2A in the cytoplasm and nucleus of HeLa cells. Moreover, western blotting and immunoprecipitation were performed to determine whether polyubiquitination and polyneddylation of PP2A were formed. The results of the present study demonstrated that USP7 was a deubiquitinating enzyme of PP2A, and regulated the ubiquitination and stability of PP2A through the K48‑linked polyubiquitin chains. Consequently, the knockdown of USP7 reduced the expression of PP2A. The data of the present study revealed the cellular association between USP7 and PP2A, a new substrate of USP7.
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Affiliation(s)
- Hyeon-Ah Do
- Department of Biomedical Science, CHA University, Seongnam‑si, Gyeonggi‑do 13488, Republic of Korea
| | - Kwang-Hyun Baek
- Department of Biomedical Science, CHA University, Seongnam‑si, Gyeonggi‑do 13488, Republic of Korea
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Affiliation(s)
- Danzhou Yang
- Purdue University, College of Pharmacy, Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave., West Lafayette, IN 47907, USA,Purdue University Center for Cancer Research, 201 S University St, West Lafayette, IN 47906, USA,Purdue University, Department of Chemistry, West Lafayette, IN, USA,Purdue Institute for Drug Discovery, West Lafayette, IN, USA
| | - Jonathan Dickerhoff
- Purdue University, College of Pharmacy, Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave., West Lafayette, IN 47907, USA
| | - William S Dynan
- Emory University School of Medicine, Department of Radiation Oncology, Department of Biochemistry, and Winship Cancer Institute, 1510 Clifton Rd NE, Atlanta GA 30322, USA
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