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Biswas H, Makinwa Y, Zou Y. Novel Cellular Functions of ATR for Therapeutic Targeting: Embryogenesis to Tumorigenesis. Int J Mol Sci 2023; 24:11684. [PMID: 37511442 PMCID: PMC10380702 DOI: 10.3390/ijms241411684] [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: 07/07/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The DNA damage response (DDR) is recognized as having an important role in cancer growth and treatment. ATR (ataxia telangiectasia mutated and Rad3-related) kinase, a major regulator of DDR, has shown significant therapeutic potential in cancer treatment. ATR inhibitors have shown anti-tumor effectiveness, not just as monotherapies but also in enhancing the effects of standard chemotherapy, radiation, and immunotherapy. The biological basis of ATR is examined in this review, as well as its functional significance in the development and therapy of cancer, and the justification for inhibiting this target as a therapeutic approach, including an assessment of the progress and status of previous decades' development of effective and selective ATR inhibitors. The current applications of these inhibitors in preclinical and clinical investigations as single medicines or in combination with chemotherapy, radiation, and immunotherapy are also fully reviewed. This review concludes with some insights into the many concerns highlighted or identified with ATR inhibitors in both the preclinical and clinical contexts, as well as potential remedies proposed.
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Affiliation(s)
| | | | - Yue Zou
- Department of Cell and Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43614, USA; (H.B.); (Y.M.)
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Hu W, Liuyang Z, Tian Y, Liang J, Zhang X, Zhang H, Wang G, Huo Y, Shentu Y, Wang J, Wang X, Lu Y, Westermarck J, Man H, Liu R. CIP2A deficiency promotes depression-like behaviors in mice through inhibition of dendritic arborization. EMBO Rep 2022; 23:e54911. [PMID: 36305233 PMCID: PMC9724669 DOI: 10.15252/embr.202254911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 08/25/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022] Open
Abstract
Major depressive disorder (MDD) is a severe mental illness. Decreased brain plasticity and dendritic fields have been consistently found in MDD patients and animal models; however, the underlying molecular mechanisms remain to be clarified. Here, we demonstrate that the deletion of cancerous inhibitor of PP2A (CIP2A), an endogenous inhibitor of protein phosphatase 2A (PP2A), leads to depression-like behaviors in mice. Hippocampal RNA sequencing analysis of CIP2A knockout mice shows alterations in the PI3K-AKT pathway and central nervous system development. In primary neurons, CIP2A stimulates AKT activity and promotes dendritic development. Further analysis reveals that the effect of CIP2A in promoting dendritic development is dependent on PP2A-AKT signaling. In vivo, CIP2A deficiency-induced depression-like behaviors and impaired dendritic arborization are rescued by AKT activation. Decreased CIP2A expression and impaired dendrite branching are observed in a mouse model of chronic unpredictable mild stress (CUMS). Indicative of clinical relevance to humans, CIP2A expression is found decreased in transcriptomes from MDD patients. In conclusion, we discover a novel mechanism that CIP2A deficiency promotes depression through the regulation of PP2A-AKT signaling and dendritic arborization.
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Affiliation(s)
- Wen‐Ting Hu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- Department of PathologyPeking University Shenzhen HospitalShenzhenChina
| | - Zhen‐Yu Liuyang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- Department of General Surgery, Sir Run Run Shaw Hospital, School of MedicineZhejiang UniversityHangzhouChina
| | - Yuan Tian
- Department of BiologyBoston UniversityBostonUSA
| | - Jia‐Wei Liang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xiao‐Lin Zhang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Hui‐Liang Zhang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Guan Wang
- Department of BiologyBoston UniversityBostonUSA
| | - Yuda Huo
- Department of BiologyBoston UniversityBostonUSA
| | - Yang‐Ping Shentu
- Department of NephrologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouChina
| | - Jian‐Zhi Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xiao‐Chuan Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - You‐ming Lu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- The Institute of Brain Research, Collaborative Innovation Center for Brain ScienceHuazhong University of Science and TechnologyWuhanChina
| | - Jukka Westermarck
- Turku Bioscience CentreUniversity of TurkuTurkuFinland
- Åbo Akademi UniversityTurkuFinland
- Institute of BiomedicineUniversity of TurkuTurkuFinland
| | - Heng‐Ye Man
- Department of BiologyBoston UniversityBostonUSA
| | - Rong Liu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- The Institute of Brain Research, Collaborative Innovation Center for Brain ScienceHuazhong University of Science and TechnologyWuhanChina
- Department of Pediatrics, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
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Glucose and Cell Context-Dependent Impact of BMI-1 Inhibitor PTC-209 on AKT Pathway in Endometrial Cancer Cells. Cancers (Basel) 2022; 14:cancers14235947. [PMID: 36497428 PMCID: PMC9739103 DOI: 10.3390/cancers14235947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 12/04/2022] Open
Abstract
PURPOSE In our study, the glucose and cell context-dependent impact of the BMI-1 inhibitor PTC-209 on the AKT pathway in endometrial cancer cells was determined. METHODS The expression of BMI-1 was inhibited by PTC-209 in endometrial cancer cells HEC-1A and Ishikawa stimulated with insulin and grown in different glucose concentrations. The migration, invasion, viability, and proliferative potential after PTC-209 treatment was assessed using wound-healing, Transwell assay, Matrigel-coated inserts, and MTT tests. Chromatin immunoprecipitation was used to determine the localization of BMI-1 protein at promoter sites of the genes tested. RESULTS BMI-1 inhibition caused an increase in PHLPP1/2 expression and a decrease in phospho-AKT level in both cell lines. The glucose concentration and insulin stimulation differentially impact the AKT pathway through BMI-1 in cells differing in PTEN statuses. The expression of BMI-1 is dependent on the glucose concentration and insulin stimulation mostly in PTEN positive HEC-1A cells. In high glucose concentrations, BMI-1 affects AKT activity through PHLPPs and in hypoglycemia mostly through PTEN. BMI-1 inhibition impacts on genes involved in SNAIL, SLUG, and CDH1 and reduces endometrial cancer cells' migratory and invasive potential. CONCLUSIONS Our results indicate that the relationship between BMI-1 and phosphatases involved in AKT regulation depends on the glucose concentration and insulin stimulation.
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Steckelings UM, Widdop RE, Sturrock ED, Lubbe L, Hussain T, Kaschina E, Unger T, Hallberg A, Carey RM, Sumners C. The Angiotensin AT 2 Receptor: From a Binding Site to a Novel Therapeutic Target. Pharmacol Rev 2022; 74:1051-1135. [PMID: 36180112 PMCID: PMC9553111 DOI: 10.1124/pharmrev.120.000281] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/22/2022] Open
Abstract
Discovered more than 30 years ago, the angiotensin AT2 receptor (AT2R) has evolved from a binding site with unknown function to a firmly established major effector within the protective arm of the renin-angiotensin system (RAS) and a target for new drugs in development. The AT2R represents an endogenous protective mechanism that can be manipulated in the majority of preclinical models to alleviate lung, renal, cardiovascular, metabolic, cutaneous, and neural diseases as well as cancer. This article is a comprehensive review summarizing our current knowledge of the AT2R, from its discovery to its position within the RAS and its overall functions. This is followed by an in-depth look at the characteristics of the AT2R, including its structure, intracellular signaling, homo- and heterodimerization, and expression. AT2R-selective ligands, from endogenous peptides to synthetic peptides and nonpeptide molecules that are used as research tools, are discussed. Finally, we summarize the known physiological roles of the AT2R and its abundant protective effects in multiple experimental disease models and expound on AT2R ligands that are undergoing development for clinical use. The present review highlights the controversial aspects and gaps in our knowledge of this receptor and illuminates future perspectives for AT2R research. SIGNIFICANCE STATEMENT: The angiotensin AT2 receptor (AT2R) is now regarded as a fully functional and important component of the renin-angiotensin system, with the potential of exerting protective actions in a variety of diseases. This review provides an in-depth view of the AT2R, which has progressed from being an enigma to becoming a therapeutic target.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert E Widdop
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Edward D Sturrock
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Lizelle Lubbe
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Tahir Hussain
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Elena Kaschina
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Thomas Unger
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Anders Hallberg
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert M Carey
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Colin Sumners
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
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Antonyan L, Ernst C. Putative Roles of SETBP1 Dosage on the SET Oncogene to Affect Brain Development. Front Neurosci 2022; 16:813430. [PMID: 35685777 PMCID: PMC9173722 DOI: 10.3389/fnins.2022.813430] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 04/19/2022] [Indexed: 12/24/2022] Open
Abstract
Mutations in SET BINDING PROTEIN 1 (SETBP1) cause two different clinically distinguishable diseases called Schinzel–Giedion syndrome (SGS) or SETBP1 deficiency syndrome (SDD). Both disorders are disorders of protein dosage, where SGS is caused by decreased rate of protein breakdown due to mutations in a proteosome targeting domain, and SDD is caused by heterozygous loss-of-function mutations leading to haploinsufficiency. While phenotypes of affected individuals support a role for SETBP1 in brain development, little is known about the mechanisms that might underlie this. The binding partner which gave SETBP1 its name is SET and there is extensive literature on this important oncogene in non-neural tissues. Here we describe different molecular complexes in which SET is involved as well as the role of these complexes in brain development. Based on this information, we postulate how SETBP1 protein dosage might influence these SET-containing molecular pathways and affect brain development. We examine the roles of SET and SETBP1 in acetylation inhibition, phosphatase activity, DNA repair, and cell cycle control. This work provides testable hypotheses for how altered SETBP1 protein dosage affects brain development.
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Gillani SQ, Reshi I, Nabi N, Un Nisa M, Sarwar Z, Bhat S, Roberts TM, Higgins JMG, Andrabi S. PCTAIRE1 promotes mitotic progression and resistance against antimitotic and apoptotic signals. J Cell Sci 2022; 135:jcs258831. [PMID: 35044463 PMCID: PMC8918779 DOI: 10.1242/jcs.258831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 12/29/2021] [Indexed: 10/24/2022] Open
Abstract
PCTAIRE1 (also known as CDK16) is a serine-threonine kinase implicated in physiological processes like neuronal development, vesicle trafficking, spermatogenesis and cell proliferation. However, its exact role in cell division remains unclear. In this study, using a library screening approach, we identified PCTAIRE1 among several candidates that resisted mitotic arrest and mitotic cell death induced by polyomavirus small T (PolST) expression in mammalian cells. Our study showed that PCTAIRE1 is a mitotic kinase that localizes at centrosomes during G2 and at spindle poles as the cells enter mitosis, and then at the midbody during cytokinesis. We also report that PCTAIRE1 protein levels fluctuate through the cell cycle and reach their peak at mitosis, during which there is an increase in PCTAIRE1 phosphorylation as well. Interestingly, knockdown of PCTAIRE1 resulted in aberrant mitosis by interfering with spindle assembly and chromosome segregation. Further, we found that PCTAIRE1 promotes resistance of cancer cells to antimitotic drugs, and this underscores the significance of PCTAIRE1 as a potential drug target for overcoming chemotherapeutic resistance. Taken together, these studies establish PCTAIRE1 as a critical mediator of mitotic progression and highlight its role in chemotherapeutic resistance. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - Irfana Reshi
- Department of Biotechnology, University of Kashmir, Srinagar 190006, India
| | - Nusrat Nabi
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Misbah Un Nisa
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Zarka Sarwar
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Sameer Bhat
- Department of Biotechnology, University of Kashmir, Srinagar 190006, India
| | - Thomas M. Roberts
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan M. G. Higgins
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University,Newcastle upon Tyne NE2 4HH, UK
| | - Shaida Andrabi
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
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Yi YW, You KS, Park JS, Lee SG, Seong YS. Ribosomal Protein S6: A Potential Therapeutic Target against Cancer? Int J Mol Sci 2021; 23:ijms23010048. [PMID: 35008473 PMCID: PMC8744729 DOI: 10.3390/ijms23010048] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/19/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022] Open
Abstract
Ribosomal protein S6 (RPS6) is a component of the 40S small ribosomal subunit and participates in the control of mRNA translation. Additionally, phospho (p)-RPS6 has been recognized as a surrogate marker for the activated PI3K/AKT/mTORC1 pathway, which occurs in many cancer types. However, downstream mechanisms regulated by RPS6 or p-RPS remains elusive, and the therapeutic implication of RPS6 is underappreciated despite an approximately half a century history of research on this protein. In addition, substantial evidence from RPS6 knockdown experiments suggests the potential role of RPS6 in maintaining cancer cell proliferation. This motivates us to investigate the current knowledge of RPS6 functions in cancer. In this review article, we reviewed the current information about the transcriptional regulation, upstream regulators, and extra-ribosomal roles of RPS6, with a focus on its involvement in cancer. We also discussed the therapeutic potential of RPS6 in cancer.
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Affiliation(s)
- Yong Weon Yi
- Department of Biochemistry, College of Medicine, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea; (Y.W.Y.); (K.S.Y.); (J.-S.P.)
- Department of Nanobiomedical Science, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea
| | - Kyu Sic You
- Department of Biochemistry, College of Medicine, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea; (Y.W.Y.); (K.S.Y.); (J.-S.P.)
- Graduate School of Convergence Medical Science, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea
| | - Jeong-Soo Park
- Department of Biochemistry, College of Medicine, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea; (Y.W.Y.); (K.S.Y.); (J.-S.P.)
| | - Seok-Geun Lee
- Graduate School, Kyung Hee University, Seoul 02447, Korea
- Correspondence: (S.-G.L.); (Y.-S.S.); Tel.: +82-2-961-2355 (S.-G.L.); +82-41-550-3875 (Y.-S.S.); Fax: +82-2-961-9623 (S.-G.L.)
| | - Yeon-Sun Seong
- Department of Biochemistry, College of Medicine, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea; (Y.W.Y.); (K.S.Y.); (J.-S.P.)
- Graduate School of Convergence Medical Science, Dankook University, Cheonan 31116, Chungcheongnam-do, Korea
- Correspondence: (S.-G.L.); (Y.-S.S.); Tel.: +82-2-961-2355 (S.-G.L.); +82-41-550-3875 (Y.-S.S.); Fax: +82-2-961-9623 (S.-G.L.)
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Sarwar Z, Nabi N, Bhat SA, Gillani SQ, Reshi I, Un Nisa M, Adelmant G, Marto J, Andrabi S. Interaction of DBC1 with polyoma small T antigen promotes its degradation and negatively regulates tumorigenesis. J Biol Chem 2021; 298:101496. [PMID: 34921839 PMCID: PMC8784333 DOI: 10.1016/j.jbc.2021.101496] [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: 05/15/2021] [Revised: 11/09/2021] [Accepted: 12/10/2021] [Indexed: 12/05/2022] Open
Abstract
Deleted in Breast Cancer 1 (DBC1) is an important metabolic sensor. Previous studies have implicated DBC1 in various cellular functions, notably cell proliferation, apoptosis, histone modification, and adipogenesis. However, current reports about the role of DBC1 in tumorigenesis are controversial and designate DBC1 alternatively as a tumor suppressor or a tumor promoter. In the present study, we report that polyoma small T antigen (PyST) associates with DBC1 in mammalian cells, and this interaction leads to the posttranslational downregulation of DBC1 protein levels. When coexpressed, DBC1 overcomes PyST-induced mitotic arrest and promotes the exit of cells from mitosis. Using both transient and stable modes of PyST expression, we also show that cellular DBC1 is subjected to degradation by LKB1, a tumor suppressor and cellular energy sensor kinase, in an AMP kinase-independent manner. Moreover, LKB1 negatively regulates the phosphorylation as well as activity of the prosurvival kinase AKT1 through DBC1 and its downstream pseudokinase substrate, Tribbles 3 (TRB3). Using both transient transfection and stable cell line approaches as well as soft agar assay, we demonstrate that DBC1 has oncogenic potential. In conclusion, our study provides insight into a novel signaling axis that connects LKB1, DBC1, TRB3, and AKT1. We propose that the LKB1–DBC1–AKT1 signaling paradigm may have an important role in the regulation of cell cycle and apoptosis and consequently tumorigenesis.
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Affiliation(s)
- Zarka Sarwar
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006
| | - Nusrat Nabi
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006
| | - Sameer Ahmed Bhat
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006
| | | | - Irfana Reshi
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006
| | - Misbah Un Nisa
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006
| | - Guillaume Adelmant
- Blais Proteomics Centre, Dana Farber Cancer Institute, Harvard University, Boston, USA
| | - Jarrod Marto
- Blais Proteomics Centre, Dana Farber Cancer Institute, Harvard University, Boston, USA
| | - Shaida Andrabi
- Department of Biochemistry, University of Kashmir, Srinagar, India, 190006.
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9
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PI3K/AKT/mTOR Signaling Pathway Is Required for JCPyV Infection in Primary Astrocytes. Cells 2021; 10:cells10113218. [PMID: 34831441 PMCID: PMC8624856 DOI: 10.3390/cells10113218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/05/2021] [Accepted: 11/12/2021] [Indexed: 12/13/2022] Open
Abstract
Astrocytes are a main target of JC polyomavirus (JCPyV) in the central nervous system (CNS), where the destruction of these cells, along with oligodendrocytes, leads to the fatal disease progressive multifocal leukoencephalopathy (PML). There is no cure currently available for PML, so it is essential to discover antivirals for this aggressive disease. Additionally, the lack of a tractable in vivo models for studying JCPyV infection makes primary cells an accurate alternative for elucidating mechanisms of viral infection in the CNS. This research to better understand the signaling pathways activated in response to JCPyV infection reveals and establishes the importance of the PI3K/AKT/mTOR signaling pathway in JCPyV infection in primary human astrocytes compared to transformed cell lines. Using RNA sequencing and chemical inhibitors to target PI3K, AKT, and mTOR, we have demonstrated the importance of this signaling pathway in JCPyV infection of primary astrocytes not observed in transformed cells. Collectively, these findings illuminate the potential for repurposing drugs that are involved with inhibition of the PI3K/AKT/mTOR signaling pathway and cancer treatment as potential therapeutics for PML, caused by this neuroinvasive virus.
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10
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Jiang Y, Li J, Li G, Liu S, Lin X, He Y, Lu J, Zhang Y, Wu J, Yang Z, Jiang Y, Wang H, Kong S, Shi G. Osteoprotegerin interacts with syndecan-1 to promote human endometrial stromal decidualization by decreasing Akt phosphorylation. Hum Reprod 2021; 35:2439-2453. [PMID: 33047116 DOI: 10.1093/humrep/deaa233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/25/2020] [Indexed: 11/12/2022] Open
Abstract
STUDY QUESTION Does osteoprotegerin (OPG) promote human endometrial stromal decidualization? SUMMARY ANSWER OPG is essential for human endometrial stromal decidualization through its interaction with syndecan-1 to decrease Akt phosphorylation. WHAT IS KNOWN ALREADY OPG (a cytokine receptor) levels are significantly increased in the circulation of pregnant women. However, the role and mechanism of OPG in human endometrial stromal cell (ESC) decidualization remain elusive. STUDY DESIGN, SIZE, DURATION We analyzed the endometrial expression of OPG in endometrial tissue samples collected from women with regular menstrual cycles (ranging from 25 to 35 days), and decidual tissue samples collected from woman with normal early pregnancy or recurrent pregnancy loss (RPL) who visited the Department of Gynecology and Obstetrics at a tertiary care center from January to October 2018. None of the subjects had hormonal treatment for at least 3 months prior to the procedure. In total, 16 women with normal early pregnancy and 15 with RPL were selected as subjects for this study. The function of OPG in decidualization was explored in a human endometrial stromal cell (HESC) line and primary cultures of HESCs. PARTICIPANTS/MATERIALS, SETTING, METHODS We collected endometrial tissues (by biopsy) from the subjects during their menstrual cycle and decidual tissues from subjects with a normal early pregnancy and those with RPL at the time of dilation and curettage. The control group comprised randomly selected women who underwent termination of an apparently normal early pregnancy. The endometrial OPG expression was analyzed using immunohistochemical staining and quantitative RT-PCR (qRT-PCR). Immunofluorescence staining and western blot, and qRT-PCR were used to explore the mRNA and protein expression, respectively, of OPG in an immortalized HESC line and in primary cultures of HESC during proliferation and decidualization. siRNA-mediated knockdown experiments were performed to examine the function of OPG in HESC proliferation and decidualization. Flow cytometry and the cell proliferation MTS assay were performed to further examine the role of OPG in HESC proliferation. We also analyzed decidual marker gene expression by qRT-PCR to assess the consequences of OPG loss for HESC decidualization. A co-immunoprecipitation (IP) assay was used to determine the potential interaction between the OPG and Syndecan-1. Western blot analysis of the rescue experiments performed using the phosphatidylinositol 3-kinase (PI3K) signaling-specific inhibitor LY294002 was used to investigate the downstream signaling pathways through which OPG could mediate HESC decidualization. MAIN RESULTS AND THE ROLE OF CHANCE OPG was expressed in both the human endometrium and in vitro decidualized ESCs. Knockdown experiments revealed that OPG loss impaired the expression of IGF-binding protein-1 (IGFBP-1) (P < 0.05) and prolactin (PRL) (P < 0.05), two specific markers of decidualization, in HESC undergoing decidualization. We also uncovered that OPG knockdown induced the aberrant activation of Akt (protein kinase B) during HESC decidualization (P < 0.05). The inhibition of Akt activation could rescue the impaired expression of the decidual markers PRL (P < 0.05) and IGFBP-1 (P < 0.05) in response to OPG knockdown. Syndecan-1 was considered a potential receptor candidate, as it was expressed in both the endometrium and in vitro cultured stromal cells. Subsequent co-IP experiments demonstrated the interaction between OPG and Syndecan-1 during decidualization. In addition, Syndecan-1 knockdown not only clearly attenuated the decidualization markers PRL (P < 0.05) and IGFBP-1 (P < 0.05) but also induced the aberrant enhancement of Akt phosphorylation in decidualized cells, consistent with the phenotype of OPG knockdown cells. Finally, we revealed that the transcript and protein expression of both OPG and Syndecan-1 was significantly lower in the decidual samples of women with RPL than in those of women with normal pregnancy (P < 0.05). LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION In this study, based on a number of approaches, it was demonstrated that OPG mediated the repression of Akt that occurs during human stromal cell decidualization, however, the molecular link between OPG and Akt signaling was not determined, and still requires further exploration. WIDER IMPLICATIONS OF THE FINDINGS OPG is required for decidualization, and a decrease in OPG levels is associated with RPL. These findings provide a new candidate molecule for the diagnosis and potential treatment of RPL. STUDY FUNDING/COMPETING INTEREST(S) This work was supported in part by the National Natural Science Foundation of China U1605223 (to G.S.), 81701457 (to Y.J.) and 81601349 (to Y.J.). The authors have no conflicts of interest to disclose.
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Affiliation(s)
- Yufei Jiang
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.,Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China.,Xiamen Key Laboratory of Reproduction and Genetics, Reproductive Medical Center, Maternal and Child Health Hospital of Xiamen, Xiamen, Fujian, China
| | - Jianing Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Gaizhen Li
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Songting Liu
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Xinjie Lin
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yan He
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Jinhua Lu
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Ying Zhang
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Jinxiang Wu
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Zhiping Yang
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yaling Jiang
- Department of Obstetrics and Gynecology, Reproductive Medical Center, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Haibin Wang
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China.,Department of Obstetrics and Gynecology, Reproductive Medical Center, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Shuangbo Kong
- Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China.,Department of Obstetrics and Gynecology, Reproductive Medical Center, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Guixiu Shi
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
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11
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Peters DK, Erickson KD, Garcea RL. Live Cell Microscopy of Murine Polyomavirus Subnuclear Replication Centers. Viruses 2020; 12:v12101123. [PMID: 33023278 PMCID: PMC7650712 DOI: 10.3390/v12101123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 09/22/2020] [Accepted: 09/30/2020] [Indexed: 01/24/2023] Open
Abstract
During polyomavirus (PyV) infection, host proteins localize to subnuclear domains, termed viral replication centers (VRCs), to mediate viral genome replication. Although the protein composition and spatial organization of VRCs have been described using high-resolution immunofluorescence microscopy, little is known about the temporal dynamics of VRC formation over the course of infection. We used live cell fluorescence microscopy to analyze VRC formation during murine PyV (MuPyV) infection of a mouse fibroblast cell line that constitutively expresses a GFP-tagged replication protein A complex subunit (GFP-RPA32). The RPA complex forms a heterotrimer (RPA70/32/14) that regulates cellular DNA replication and repair and is a known VRC component. We validated previous observations that GFP-RPA32 relocalized to sites of cellular DNA damage in uninfected cells and to VRCs in MuPyV-infected cells. We then used GFP-RPA32 as a marker of VRC formation and expansion during live cell microscopy of infected cells. VRC formation occurred at variable times post-infection, but the rate of VRC expansion was similar between cells. Additionally, we found that the early viral protein, small TAg (ST), was required for VRC expansion but not VRC formation, consistent with the role of ST in promoting efficient vDNA replication. These results demonstrate the dynamic nature of VRCs over the course of infection and establish an approach for analyzing viral replication in live cells.
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Affiliation(s)
- Douglas K. Peters
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309, USA; (D.K.P.); (K.D.E.)
| | - Kimberly D. Erickson
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309, USA; (D.K.P.); (K.D.E.)
| | - Robert L. Garcea
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309, USA; (D.K.P.); (K.D.E.)
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309, USA
- Correspondence:
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12
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Makinwa Y, Cartwright BM, Musich PR, Li Z, Biswas H, Zou Y. PP2A Regulates Phosphorylation-Dependent Isomerization of Cytoplasmic and Mitochondrial-Associated ATR by Pin1 in DNA Damage Responses. Front Cell Dev Biol 2020; 8:813. [PMID: 32984322 PMCID: PMC7484947 DOI: 10.3389/fcell.2020.00813] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/31/2020] [Indexed: 11/13/2022] Open
Abstract
Ataxia telangiectasia and Rad3-related protein (ATR) is a serine/threonine-protein kinase of the PI3K family and is well known for its key role in regulating DNA damage responses in the nucleus. In addition to its nuclear functions, ATR also was found to be a substrate of the prolyl isomerase Pin1 in the cytoplasm where Pin1 isomerizes cis ATR at the Ser428-Pro429 motif, leading to formation of trans ATR. Cis ATR is an antiapoptotic protein at mitochondria upon UV damage. Here we report that Pin1’s activity on cis ATR requires the phosphorylation of the S428 residue of ATR and describe the molecular mechanism by which Pin1-mediated ATR isomerization in the cytoplasm is regulated. We identified protein phosphatase 2A (PP2A) as the phosphatase that dephosphorylates Ser428 following DNA damage. The dephosphorylation led to an increased level of the antiapoptotic cis ATR (ATR-H) in the cytoplasm and, thus, its accumulation at mitochondria via binding with tBid. Inhibition or depletion of PP2A promoted the isomerization by Pin1, resulting in a reduction of cis ATR with an increased level of trans ATR. We conclude that PP2A plays an important role in regulating ATR’s anti-apoptotic activity at mitochondria in response to DNA damage. Our results also imply a potential strategy in enhancing cancer therapies via selective moderation of cis ATR levels.
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Affiliation(s)
- Yetunde Makinwa
- Department of Cancer Biology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Brian M Cartwright
- Department of Biomedical Sciences, JH Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Phillip R Musich
- Department of Biomedical Sciences, JH Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Zhengke Li
- Department of Biomedical Sciences, JH Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Himadri Biswas
- Department of Cancer Biology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Yue Zou
- Department of Cancer Biology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States.,Department of Biomedical Sciences, JH Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
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13
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PRMT1-dependent methylation of BRCA1 contributes to the epigenetic defense of breast cancer cells against ionizing radiation. Sci Rep 2020; 10:13275. [PMID: 32764667 PMCID: PMC7413540 DOI: 10.1038/s41598-020-70289-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022] Open
Abstract
The therapeutic effect of irradiation is thought to come from DNA damage that affects rapidly proliferating cancer cells; however, resistant cells rapidly initiate mechanisms to repair such damage. While DNA repair mechanisms responsible for cancer cell survival following DNA damage are understood, less is known about the epigenetic mechanisms resulting in resistance to radiotherapy. Although changes in DNA methylation are related to mechanisms of long-term resistance, it is more likely that the methylation state of a series of proteins could be responsible for the first-line of defense of cancer cells against irradiation. In this study, we observed that irradiation of breast cancer cells was accompanied by an overproduction in S-adenosylmethionine, which increases the activity of cellular methylases. We found that by activating PRMT1, irradiation triggers a BRCA1-dependent program that results in efficient DNA repair and inhibition of apoptosis. Depletion of PRMT1 in irradiated cells resulted in a switch of BRCA1 functions from repair and survival in the nucleus to activation of cell death signals in the cytoplasm. We conclude that by modulating the cellular localization of BRCA1, PRMT1 is an important regulator of the oncogenic functions of BRCA1, contributing to the epigenetic defense of breast cancer cells against ionizing radiation.
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14
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Schramm K, Iskar M, Statz B, Jäger N, Haag D, Słabicki M, Pfister SM, Zapatka M, Gronych J, Jones DTW, Lichter P. DECIPHER pooled shRNA library screen identifies PP2A and FGFR signaling as potential therapeutic targets for diffuse intrinsic pontine gliomas. Neuro Oncol 2020; 21:867-877. [PMID: 30943283 DOI: 10.1093/neuonc/noz057] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Diffuse intrinsic pontine gliomas (DIPGs) are highly aggressive pediatric brain tumors that are characterized by a recurrent mutation (K27M) within the histone H3 encoding genes H3F3A and HIST1H3A/B/C. These mutations have been shown to induce a global reduction in the repressive histone modification H3K27me3, which together with widespread changes in DNA methylation patterns results in an extensive transcriptional reprogramming hampering the identification of single therapeutic targets based on a molecular rationale. METHODS We applied a large-scale gene knockdown approach using a pooled short hairpin (sh)RNA library in combination with next-generation sequencing in order to identify DIPG-specific vulnerabilities. The therapeutic potential of specific inhibitors of candidate targets was validated in a secondary drug screen. RESULTS We identified fibroblast growth factor receptor (FGFR) signaling and the serine/threonine protein phosphatase 2A (PP2A) as top depleted hits in patient-derived DIPG cell cultures and validated their lethal potential by FGF ligand depletion and genetic knockdown of the PP2A structural subunit PPP2R1A. Further, pharmacological inhibition of FGFR and PP2A signaling through ponatinib and LB-100 treatment, respectively, exhibited strong tumor-specific anti-proliferative and apoptotic activity in cultured DIPG cells. CONCLUSIONS Our findings suggest FGFR and PP2A signaling as potential new therapeutic targets for the treatment of DIPGs.
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Affiliation(s)
- Kathrin Schramm
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Murat Iskar
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Britta Statz
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Natalie Jäger
- Division of Pediatric Neurooncology, DKFZ, and Hopp Children's Cancer Center Heidelberg, Heidelberg, Germany
| | - Daniel Haag
- Division of Pediatric Neurooncology, DKFZ, and Hopp Children's Cancer Center Heidelberg, Heidelberg, Germany
| | - Mikołaj Słabicki
- Molecular Therapy in Hematology and Oncology, Department of Translational Oncology, National Center for Tumor Diseases and DKFZ, Heidelberg, Germany
| | - Stefan M Pfister
- Division of Pediatric Neurooncology, DKFZ, and Hopp Children's Cancer Center Heidelberg, Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Marc Zapatka
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jan Gronych
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - David T W Jones
- Pediatric Glioma Research Group, Hopp Children's Cancer Center Heidelberg and DKFZ, Heidelberg, Germany
| | - Peter Lichter
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany
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15
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Polyomavirus Small T Antigen Induces Apoptosis in Mammalian Cells through the UNC5B Pathway in a PP2A-Dependent Manner. J Virol 2020; 94:JVI.02187-19. [PMID: 32404521 DOI: 10.1128/jvi.02187-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/02/2020] [Indexed: 11/20/2022] Open
Abstract
UNC5B is a dependence receptor that promotes survival in the presence of its ligand, netrin-1, while inducing cell death in its absence. The receptor has an important role in the development of the nervous and vascular systems. It is also involved in the normal turnover of intestinal epithelium. Netrin-1 and UNC5B are deregulated in multiple cancers, including colorectal, neuroblastoma, and breast tumors. However, the detailed mechanism of UNC5B function is not fully understood. We have utilized the murine polyomavirus small T antigen (PyST) as a tool to study UNC5B-mediated apoptosis. PyST is known to induce mitotic arrest followed by extensive cell death in mammalian cells. Our results show that the expression of PyST increases mRNA levels of UNC5B by approximately 3-fold in osteosarcoma cells (U2OS) and also stabilizes UNC5B at the posttranslational level. Furthermore, UNC5B is upregulated predominantly in those cells that undergo mitotic arrest upon PyST expression. Interestingly, although its expression was previously reported to be regulated by p53, our data show that the increase in UNC5B levels by PyST is p53 independent. The posttranslational stabilization of UNC5B by PyST is regulated by the interaction of PyST with PP2A. We also show that netrin-1 expression, which is known to inhibit UNC5B apoptotic activity, promotes survival of PyST-expressing cells. Our results thus suggest an important role of UNC5B in small-T antigen-induced mitotic catastrophe that also requires PP2A.IMPORTANCE UNC5B, PP2A, and netrin-1 are deregulated in a variety of cancers. UNC5B and PP2A are regarded as tumor suppressors, as they promote apoptosis and are deleted or mutated in many cancers. In contrast, netrin-1 promotes survival by inhibiting dependence receptors, including UNC5B, and is upregulated in many cancers. Here, we show that UNC5B-mediated apoptosis can occur independently of p53 but in a PP2A-dependent manner. A substantial percentage of cancers arise due to p53 mutations and are insensitive to chemotherapeutic treatments that activate p53. Unexpectedly, treatment of cancers having functional p53 with many conventional drugs leads to the upregulation of netrin-1 through activated p53, which is counterintuitive. Therefore, understanding the p53-independent mechanisms of the netrin-UNC5B axis, such as those involving PP2A, assumes greater clinical significance. Anticancer strategies utilizing anti-netrin-1 antibody treatment are already in clinical trials.
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16
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Peters DK, Garcea RL. Murine polyomavirus DNA transitions through spatially distinct nuclear replication subdomains during infection. PLoS Pathog 2020; 16:e1008403. [PMID: 32203554 PMCID: PMC7117779 DOI: 10.1371/journal.ppat.1008403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/02/2020] [Accepted: 02/13/2020] [Indexed: 12/16/2022] Open
Abstract
The replication of small DNA viruses requires both host DNA replication and repair factors that are often recruited to subnuclear domains termed viral replication centers (VRCs). Aside from serving as a spatial focus for viral replication, little is known about these dynamic areas in the nucleus. We investigated the organization and function of VRCs during murine polyomavirus (MuPyV) infection using 3D structured illumination microscopy (3D-SIM). We localized MuPyV replication center components, such as the viral large T-antigen (LT) and the cellular replication protein A (RPA), to spatially distinct subdomains within VRCs. We found that viral DNA (vDNA) trafficked sequentially through these subdomains post-synthesis, suggesting their distinct functional roles in vDNA processing. Additionally, we observed disruption of VRC organization and vDNA trafficking during mutant MuPyV infections or inhibition of DNA synthesis. These results reveal a dynamic organization of VRC components that coordinates virus replication.
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Affiliation(s)
- Douglas K. Peters
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Robert L. Garcea
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, United States of America
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, United States of America
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17
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Horníková L, Bruštíková K, Forstová J. Microtubules in Polyomavirus Infection. Viruses 2020; 12:E121. [PMID: 31963741 PMCID: PMC7019765 DOI: 10.3390/v12010121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/12/2022] Open
Abstract
Microtubules, part of the cytoskeleton, are indispensable for intracellular movement, cell division, and maintaining cell shape and polarity. In addition, microtubules play an important role in viral infection. In this review, we summarize the role of the microtubules' network during polyomavirus infection. Polyomaviruses usurp microtubules and their motors to travel via early and late acidic endosomes to the endoplasmic reticulum. As shown for SV40, kinesin-1 and microtubules are engaged in the release of partially disassembled virus from the endoplasmic reticulum to the cytosol, and dynein apparently assists in the further disassembly of virions prior to their translocation to the cell nucleus-the place of their replication. Polyomavirus gene products affect the regulation of microtubule dynamics. Early T antigens destabilize microtubules and cause aberrant mitosis. The role of these activities in tumorigenesis has been documented. However, its importance for productive infection remains elusive. On the other hand, in the late phase of infection, the major capsid protein, VP1, of the mouse polyomavirus, counteracts T-antigen-induced destabilization. It physically binds microtubules and stabilizes them. The interaction results in the G2/M block of the cell cycle and prolonged S phase, which is apparently required for successful completion of the viral replication cycle.
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Affiliation(s)
| | | | - Jitka Forstová
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 25250 Vestec, Czech Republic; (L.H.); (K.B.)
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18
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Guo B, Wu S, Zhu X, Zhang L, Deng J, Li F, Wang Y, Zhang S, Wu R, Lu J, Zhou Y. Micropeptide CIP2A-BP encoded by LINC00665 inhibits triple-negative breast cancer progression. EMBO J 2020; 39:e102190. [PMID: 31755573 PMCID: PMC6939193 DOI: 10.15252/embj.2019102190] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 10/10/2019] [Accepted: 10/15/2019] [Indexed: 01/22/2023] Open
Abstract
TGF-β signaling pathway plays a key role in breast cancer metastasis. Recent studies suggest that TGF-β regulates tumor progression and invasion not only via transcriptional regulation, but also via translational regulation. Using both bioinformatics and experimental tools, we identified a micropeptide CIP2A-BP encoded by LINC00665, whose translation was downregulated by TGF-β in breast cancer cell lines. Using TNBC cell lines, we showed that TGF-β-activated Smad signaling pathway induced the expression of translation inhibitory protein 4E-BP1, which inhibited eukaryote translation initiation factor elF4E, leading to reduced translation of CIP2A-BP from LINC00665. CIP2A-BP directly binds tumor oncogene CIP2A to replace PP2A's B56γ subunit, thus releasing PP2A activity, which inhibits PI3K/AKT/NFκB pathway, resulting in decreased expression levels of MMP-2, MMP-9, and Snail. Downregulation of CIP2A-BP in TNBC patients was significantly associated with metastasis and poor overall survival. In the MMTV-PyMT model, either introducing CIP2A-BP gene or direct injection of CIP2A-BP micropeptide significantly reduced lung metastases and improved overall survival. In conclusion, we provide evidence that CIP2A-BP is both a prognostic marker and a novel therapeutic target for TNBC.
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Affiliation(s)
- Binbin Guo
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Siqi Wu
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Xun Zhu
- Department of General SurgeryThe Second Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Liyuan Zhang
- Department of Radiotherapy & OncologyThe Second Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Jieqiong Deng
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Fang Li
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Yirong Wang
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Shenghua Zhang
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Rui Wu
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
| | - Jiachun Lu
- The State Key Lab of Respiratory DiseaseThe First Affiliated HospitalThe School of Public HealthGuangzhou Medical UniversityGuangzhouChina
| | - Yifeng Zhou
- Department of GeneticsMedical College of Soochow UniversitySuzhouChina
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19
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Kauko O, O'Connor CM, Kulesskiy E, Sangodkar J, Aakula A, Izadmehr S, Yetukuri L, Yadav B, Padzik A, Laajala TD, Haapaniemi P, Momeny M, Varila T, Ohlmeyer M, Aittokallio T, Wennerberg K, Narla G, Westermarck J. PP2A inhibition is a druggable MEK inhibitor resistance mechanism in KRAS-mutant lung cancer cells. Sci Transl Med 2019; 10:10/450/eaaq1093. [PMID: 30021885 DOI: 10.1126/scitranslmed.aaq1093] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 04/21/2018] [Accepted: 06/08/2018] [Indexed: 12/15/2022]
Abstract
Kinase inhibitor resistance constitutes a major unresolved clinical challenge in cancer. Furthermore, the role of serine/threonine phosphatase deregulation as a potential cause for resistance to kinase inhibitors has not been thoroughly addressed. We characterize protein phosphatase 2A (PP2A) activity as a global determinant of KRAS-mutant lung cancer cell resistance across a library of >200 kinase inhibitors. The results show that PP2A activity modulation alters cancer cell sensitivities to a large number of kinase inhibitors. Specifically, PP2A inhibition ablated mitogen-activated protein kinase kinase (MEK) inhibitor response through the collateral activation of AKT/mammalian target of rapamycin (mTOR) signaling. Combination of mTOR and MEK inhibitors induced cytotoxicity in PP2A-inhibited cells, but even this drug combination could not abrogate MYC up-regulation in PP2A-inhibited cells. Treatment with an orally bioavailable small-molecule activator of PP2A DT-061, in combination with the MEK inhibitor AZD6244, resulted in suppression of both p-AKT and MYC, as well as tumor regression in two KRAS-driven lung cancer mouse models. DT-061 therapy also abrogated MYC-driven tumorigenesis. These data demonstrate that PP2A deregulation drives MEK inhibitor resistance in KRAS-mutant cells. These results emphasize the need for better understanding of phosphatases as key modulators of cancer therapy responses.
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Affiliation(s)
- Otto Kauko
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Institute of Biomedicine, University of Turku, 20520 Turku, Finland.,TuBS and TuDMM Doctoral Programmes, University of Turku, 20520 Turku, Finland
| | - Caitlin M O'Connor
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106-7285, USA
| | - Evgeny Kulesskiy
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Jaya Sangodkar
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Anna Aakula
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Sudeh Izadmehr
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Laxman Yetukuri
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Bhagwan Yadav
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Artur Padzik
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Teemu Daniel Laajala
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland.,Department of Mathematics and Statistics, University of Turku, 20520 Turku, Finland
| | - Pekka Haapaniemi
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Majid Momeny
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Taru Varila
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Michael Ohlmeyer
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland.,Department of Mathematics and Statistics, University of Turku, 20520 Turku, Finland
| | - Krister Wennerberg
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Goutham Narla
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106-7285, USA
| | - Jukka Westermarck
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland. .,Institute of Biomedicine, University of Turku, 20520 Turku, Finland
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20
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Stafman LL, Williams AP, Marayati R, Aye JM, Stewart JE, Mroczek-Musulman E, Beierle EA. PP2A activation alone and in combination with cisplatin decreases cell growth and tumor formation in human HuH6 hepatoblastoma cells. PLoS One 2019; 14:e0214469. [PMID: 30969990 PMCID: PMC6457532 DOI: 10.1371/journal.pone.0214469] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/13/2019] [Indexed: 12/18/2022] Open
Abstract
Despite an increase in incidence, treatments for hepatoblastoma remain virtually unchanged for the past 20 years, emphasizing the need for novel therapeutics. FTY720 (fingolimod) is an immunomodulator approved for use in multiple sclerosis in children that has been demonstrated to have anti-cancer properties in multiple cancer types. We have demonstrated that FTY720 activates PP2A in hepatoblastoma, but does not do so via inhibition of the endogenous inhibitors, CIP2A and I2PP2A, as previously observed in other cancers. PP2A activation in hepatoblastoma decreased cell viability, proliferation, and motility and induced apoptosis. In a subcutaneous xenograft model, FTY720 decreased tumor growth. FTY720 in combination with the standard chemotherapeutic, cisplatin, decreased proliferation in a synergistic manner. Finally, animals bearing subcutaneous hepatoblastoma xenografts treated with FTY720 and cisplatin in combination had significantly decreased tumor growth compared to those treated with either drug alone. These findings show that targeting PP2A with FTY70 shows promise in the treatment of hepatoblastoma and that combining FTY720 with cisplatin may be a novel and effective strategy to better treat this devastating pediatric liver tumor.
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Affiliation(s)
- Laura L. Stafman
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL, United States of America
| | - Adele P. Williams
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL, United States of America
| | - Raoud Marayati
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL, United States of America
| | - Jamie M. Aye
- Division of Pediatric Hematology Oncology, Department of Pediatrics, University of Alabama, Birmingham, Birmingham, AL, United States of America
| | - Jerry E. Stewart
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL, United States of America
| | | | - Elizabeth A. Beierle
- Division of Pediatric Surgery, Department of Surgery, University of Alabama, Birmingham, Birmingham, AL, United States of America
- * E-mail:
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21
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Tohmé R, Izadmehr S, Gandhe S, Tabaro G, Vallabhaneni S, Thomas A, Vasireddi N, Dhawan NS, Ma’ayan A, Sharma N, Galsky MD, Ohlmeyer M, Sangodkar J, Narla G. Direct activation of PP2A for the treatment of tyrosine kinase inhibitor-resistant lung adenocarcinoma. JCI Insight 2019; 4:125693. [PMID: 30830869 PMCID: PMC6478418 DOI: 10.1172/jci.insight.125693] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/11/2019] [Indexed: 12/17/2022] Open
Abstract
Although tyrosine kinase inhibitors (TKIs) have demonstrated significant efficacy in advanced lung adenocarcinoma (LUAD) patients with pathogenic alterations in EGFR, most patients develop acquired resistance to these agents via mechanisms enabling the sustained activation of the PI3K and MAPK oncogenic pathways downstream of EGFR. The tumor suppressor protein phosphatase 2A (PP2A) acts as a negative regulator of these pathways. We hypothesize that activation of PP2A simultaneously inhibits the PI3K and MAPK pathways and represents a promising therapeutic strategy for the treatment of TKI-resistant LUAD. After establishing the efficacy of small molecule activators of PP2A (SMAPs) in a transgenic EGFRL858R model and TKI-sensitive cell lines, we evaluated their therapeutic potential in vitro and in vivo in TKI-resistant models. PP2A activation resulted in apoptosis, significant tumor growth inhibition, and downregulation of PI3K and MAPK pathways. Combination of SMAPs and TKI afatinib resulted in an enhanced effect on the downregulation of the PI3K pathway via degradation of the PP2A endogenous inhibitor CIP2A. An improved effect on tumor growth inhibition was observed in a TKI-resistant xenograft mouse model treated with a combination of both agents. These collective data support the development of PP2A activators for the treatment of TKI-resistant LUAD.
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Affiliation(s)
- Rita Tohmé
- Department of Molecular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sudeh Izadmehr
- Division of Hematology and Medical Oncology, Tisch Cancer Institute
| | - Sai Gandhe
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Giancarlo Tabaro
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sanjay Vallabhaneni
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ava Thomas
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Neal Vasireddi
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Avi Ma’ayan
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Neelesh Sharma
- University Hospitals Seidman Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Michael Ohlmeyer
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Jaya Sangodkar
- Division of Genetic Medicine, Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Goutham Narla
- Division of Genetic Medicine, Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
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22
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Contribution of p62/SQSTM1 to PDGF-BB-induced myofibroblast-like phenotypic transition in vascular smooth muscle cells lacking Smpd1 gene. Cell Death Dis 2018; 9:1145. [PMID: 30451833 PMCID: PMC6242941 DOI: 10.1038/s41419-018-1197-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 12/17/2022]
Abstract
Accumulating evidence indicates a critical role of autophagy in regulating vascular smooth muscle cell (SMC) homeostasis in atherogenesis. However, little is known about the modulatory role of autophagy in PDGF-BB-induced SMC transition towards the synthetic phenotype and extracellular matrix remodeling. We recently demonstrated that acid sphingomyelinase (ASM, encoded by Smpd1 gene) controls autophagy maturation in coronary arterial SMCs. Here, we demonstrate that PDGF-BB stimulation causes a myofibroblast-like non-canonical synthetic phenotype transition in Smpd1−/− SMCs. These non-canonical phenotypic changes induced by PDGF-BB in Smpd1−/− SMCs were characterized by increased expression of fibroblast-specific protein (FSP-1), massive deposition of collagen type I, decreased cell size, elevated inflammatory status with enhanced cytokine release and adhesion molecule expression. Mechanistically, PDGF-BB induces prolonged Akt activation that causes decreased autophagosome biogenesis and thereby exaggerates p62/SQSTM1 accumulation in Smpd1−/− SMCs. More importantly, Akt inhibition or p62/SQSTM1 gene silencing attenuates PDGF-BB-induced phenotypic changes in Smpd1−/− SMCs. This first demonstration of a p62/SQSTM1-dependent myofibroblast-like phenotypic transition in Smpd1−/− SMCs suggests that ASM-mediated autophagy pathway contributes to maintaining the arterial smooth muscle homeostasis in situation of vascular remodeling during atherosclerosis.
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23
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PpV, acting via the JNK pathway, represses apoptosis during normal development of Drosophila wing. Apoptosis 2018; 23:554-562. [DOI: 10.1007/s10495-018-1479-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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24
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Wang D, Uhrin P, Mocan A, Waltenberger B, Breuss JM, Tewari D, Mihaly-Bison J, Huminiecki Ł, Starzyński RR, Tzvetkov NT, Horbańczuk J, Atanasov AG. Vascular smooth muscle cell proliferation as a therapeutic target. Part 1: molecular targets and pathways. Biotechnol Adv 2018; 36:1586-1607. [PMID: 29684502 DOI: 10.1016/j.biotechadv.2018.04.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/15/2018] [Accepted: 04/18/2018] [Indexed: 12/16/2022]
Abstract
Cardiovascular diseases are a major cause of human death worldwide. Excessive proliferation of vascular smooth muscle cells contributes to the etiology of such diseases, including atherosclerosis, restenosis, and pulmonary hypertension. The control of vascular cell proliferation is complex and encompasses interactions of many regulatory molecules and signaling pathways. Herein, we recapitulated the importance of signaling cascades relevant for the regulation of vascular cell proliferation. Detailed understanding of the mechanism underlying this process is essential for the identification of new lead compounds (e.g., natural products) for vascular therapies.
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Affiliation(s)
- Dongdong Wang
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, ul. Postepu 36A, Jastrzębiec, 05-552 Magdalenka, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria; Institute of Clinical Chemistry, University Hospital Zurich, Wagistrasse 14, 8952 Schlieren, Switzerland
| | - Pavel Uhrin
- Center for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria.
| | - Andrei Mocan
- Department of Pharmaceutical Botany, "Iuliu Hațieganu" University of Medicine and Pharmacy, Strada Gheorghe Marinescu 23, 400337 Cluj-Napoca, Romania; Institute for Life Sciences, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăştur 3-5, 400372 Cluj-Napoca, Romania
| | - Birgit Waltenberger
- Institute of Pharmacy/Pharmacognosy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Johannes M Breuss
- Center for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Devesh Tewari
- Department of Pharmaceutical Sciences, Faculty of Technology, Kumaun University, Bhimtal, 263136 Nainital, Uttarakhand, India
| | - Judit Mihaly-Bison
- Center for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Łukasz Huminiecki
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, ul. Postepu 36A, Jastrzębiec, 05-552 Magdalenka, Poland
| | - Rafał R Starzyński
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, ul. Postepu 36A, Jastrzębiec, 05-552 Magdalenka, Poland
| | - Nikolay T Tzvetkov
- Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany; NTZ Lab Ltd., Krasno Selo 198, 1618 Sofia, Bulgaria
| | - Jarosław Horbańczuk
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, ul. Postepu 36A, Jastrzębiec, 05-552 Magdalenka, Poland
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, ul. Postepu 36A, Jastrzębiec, 05-552 Magdalenka, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
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25
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Airo AM, Urbanowski MD, Lopez-Orozco J, You JH, Skene-Arnold TD, Holmes C, Yamshchikov V, Malik-Soni N, Frappier L, Hobman TC. Expression of flavivirus capsids enhance the cellular environment for viral replication by activating Akt-signalling pathways. Virology 2018; 516:147-157. [PMID: 29358114 DOI: 10.1016/j.virol.2018.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/04/2018] [Accepted: 01/09/2018] [Indexed: 01/23/2023]
Abstract
Flaviviruses depend on multiple host pathways during their life cycles and have evolved strategies to avoid the innate immune response. Previously, we showed that the West Nile virus capsid protein plays a role in this process by blocking apoptosis. In this study, we examined how expression of capsid proteins from several flaviviruses affects apoptosis and other host processes that impact virus replication. All of the tested capsid proteins protected cells from Fas-dependent apoptosis through a mechanism that requires activated Akt. Capsid expression upregulated other Akt-dependent cellular processes including expression of glucose transporter 1 and mitochondrial metabolism. Protein phosphatase 1, which is known to inactivate Akt, was identified as a DENV capsid interacting protein. This suggests that DENV capsid expression activates Akt by sequestering phosphatases that downregulate phospho-Akt. Capsid-dependent upregulation of Akt would enhance downstream signalling pathways that affect cell survival and metabolism, thus providing a favourable environment for virus replication.
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Affiliation(s)
- Adriana M Airo
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | | | | | - Jae Hwan You
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | | | - Charles Holmes
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | | | - Natasha Malik-Soni
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Tom C Hobman
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada; Department of Cell Biology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Canada; Women & Children's Health Research Institute, University of Alberta, Canada.
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26
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The role of CIP2A in cancer: A review and update. Biomed Pharmacother 2017; 96:626-633. [DOI: 10.1016/j.biopha.2017.08.146] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/01/2017] [Accepted: 08/13/2017] [Indexed: 12/11/2022] Open
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27
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Han X, Li B, Ye X, Mulatibieke T, Wu J, Dai J, Wu D, Ni J, Zhang R, Xue J, Wan R, Wang X, Hu G. Dopamine D 2 receptor signalling controls inflammation in acute pancreatitis via a PP2A-dependent Akt/NF-κB signalling pathway. Br J Pharmacol 2017; 174:4751-4770. [PMID: 28963856 PMCID: PMC5727253 DOI: 10.1111/bph.14057] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Dopamine has multiple anti-inflammatory effects, but its role and molecular mechanism in acute pancreatitis (AP) are unclear. We investigated the role of dopamine signalling in the inflammatory response in AP. EXPERIMENTAL APPROACH Changes in pancreatic dopaminergic system and effects of dopamine, antagonists and agonists of D1 and D2 dopamine receptors were analysed in wild-type and pancreas-specific Drd2-/- mice with AP (induced by caerulein and LPS or L-arginine) and pancreatic acinar cells with or without cholecystokinin (CCK) stimulation. The severity of pancreatitis was assessed by measuring serum amylase and lipase and histological assessments. The NF-κB signalling pathway was evaluated, and macrophage and neutrophil migration assessed by Transwell assay. KEY RESULTS Pancreatic dopamine synthetase and metabolic enzyme levels were increased, whereas D1 and D2 receptors were decreased in AP. Dopamine reduced inflammation in CCK-stimulated pancreatic acinar cells by inhibiting the NF-κB pathway. Moreover, the protective effects of dopamine were blocked by a D2 antagonist, but not a D1 antagonist. A D2 agonist reduced pancreatic damage and levels of p-IκBα, p-NF-κBp65, TNFα, IL-1β and IL-6 in AP. Pancreas-specific Drd2-/- aggravated AP. Also, the D2 agonist activated PP2A and inhibited the phosphorylation of Akt, IKK, IκBα and NF-κB and production of inflammatory cytokines and chemokines. Furthermore, it inhibited the migration of macrophages and neutrophils by reducing the expression of CCL2 and CXCL2. A PP2A inhibitor attenuated these protective effects of the D2 agonist. CONCLUSIONS AND IMPLICATIONS D2 receptors control pancreatic inflammation in AP by inhibiting NF-κB activation via a PP2A-dependent Akt signalling pathway.
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Affiliation(s)
- Xiao Han
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Bin Li
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xin Ye
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Tunike Mulatibieke
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Jianghong Wu
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Juanjuan Dai
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Deqing Wu
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Jianbo Ni
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Ruling Zhang
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Jing Xue
- State Key Laboratory of Oncogenes and Related Genes, Stem Cell Research Centre, Ren Ji HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Rong Wan
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xingpeng Wang
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Guoyong Hu
- Department of Gastroenterology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic DiseaseShanghai Jiao Tong University School of MedicineShanghaiChina
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28
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Reshi I, Sarwar Z, Bhat SA, Gillani SQ, Shah M, Fazili KM, Andrabi S. Polyoma small T upregulates the expression of cytoskeletal proteins in mammalian cells during mitosis. Int J Biol Macromol 2017; 107:2279-2284. [PMID: 29104053 DOI: 10.1016/j.ijbiomac.2017.10.110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/16/2017] [Indexed: 12/01/2022]
Abstract
Mammalian cells expressing murine polyoma small T antigen are known to undergo prolonged mitotic arrest followed by extensive cell death. However, the detailed mechanism of this process is not fully understood. While studying the mechanism related to small T induced mitotic arrest in mammalian cells, we observed that the expression of various cytoskeletal proteins was unusually altered in polyoma small T expressing cell line. Since most of the cytoskeletal proteins are reoriented during mitosis and are involved in spindle formation, so it was pertinent to investigate the expression of these genes in PyST expressing cell line. In this study, we evaluated the expression of tubulin, vinculin and actin. We report that polyoma small T antigen leads to upregulation of tubulin and vinculin in a time dependent manner with tubulin expression being most significantly affected. Intriguingly, we demonstrate that dividing cells normally change the expression of these proteins during mitotic progression. The alteration in cytoskeletal elements specifically occurs during mitosis as cells arrested in replicative phase did not show any change. Together these results reveal that the protein levels of tubulin and vinculin do not remain constant throughout cell cycle but change during mitosis and in polyoma small T expressing cells.
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Affiliation(s)
- Irfana Reshi
- Department of Biotechnology, University of Kashmir, India
| | - Zarka Sarwar
- Department of Biochemistry, University of Kashmir, India
| | | | | | - Misbah Shah
- Department of Biochemistry, University of Kashmir, India
| | | | - Shaida Andrabi
- Department of Biochemistry, University of Kashmir, India.
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Lehmann S, Bass JJ, Barratt TF, Ali MZ, Szewczyk NJ. Functional phosphatome requirement for protein homeostasis, networked mitochondria, and sarcomere structure in C. elegans muscle. J Cachexia Sarcopenia Muscle 2017; 8:660-672. [PMID: 28508547 PMCID: PMC5566650 DOI: 10.1002/jcsm.12196] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 12/08/2016] [Accepted: 01/26/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Skeletal muscle is central to locomotion and metabolic homeostasis. The laboratory worm Caenorhabditis elegans has been developed into a genomic model for assessing the genes and signals that regulate muscle development and protein degradation. Past work has identified a receptor tyrosine kinase signalling network that combinatorially controls autophagy, nerve signal to muscle to oppose proteasome-based degradation, and extracellular matrix-based signals that control calpain and caspase activation. The last two discoveries were enabled by following up results from a functional genomic screen of known regulators of muscle. Recently, a screen of the kinome requirement for muscle homeostasis identified roughly 40% of kinases as required for C. elegans muscle health; 80 have identified human orthologues and 53 are known to be expressed in skeletal muscle. To complement this kinome screen, here, we screen most of the phosphatases in C. elegans. METHODS RNA interference was used to knockdown phosphatase-encoding genes. Knockdown was first conducted during development with positive results also knocked down only in fully developed adult muscle. Protein homeostasis, mitochondrial structure, and sarcomere structure were assessed using transgenic reporter proteins. Genes identified as being required to prevent protein degradation were also knocked down in conditions that blocked proteasome or autophagic degradation. Genes identified as being required to prevent autophagic degradation were also assessed for autophagic vesicle accumulation using another transgenic reporter. Lastly, bioinformatics were used to look for overlap between kinases and phosphatases required for muscle homeostasis, and the prediction that one phosphatase was required to prevent mitogen-activated protein kinase activation was assessed by western blot. RESULTS A little over half of all phosphatases are each required to prevent abnormal development or maintenance of muscle. Eighty-six of these phosphatases have known human orthologues, 57 of which are known to be expressed in human skeletal muscle. Of the phosphatases required to prevent abnormal muscle protein degradation, roughly half are required to prevent increased autophagy. CONCLUSIONS A significant portion of both the kinome and phosphatome are required for establishing and maintaining C. elegans muscle health. Autophagy appears to be the most commonly triggered form of protein degradation in response to disruption of phosphorylation-based signalling. The results from these screens provide measurable phenotypes for analysing the combined contribution of kinases and phosphatases in a multi-cellular organism and suggest new potential regulators of human skeletal muscle for further analysis.
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Affiliation(s)
- Susann Lehmann
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, Medical School, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Joseph J Bass
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, Medical School, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Thomas F Barratt
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, Medical School, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Mohammed Z Ali
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, Medical School, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Nathaniel J Szewczyk
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, Medical School, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
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Szymiczek A, Pastorino S, Larson D, Tanji M, Pellegrini L, Xue J, Li S, Giorgi C, Pinton P, Takinishi Y, Pass HI, Furuya H, Gaudino G, Napolitano A, Carbone M, Yang H. FTY720 inhibits mesothelioma growth in vitro and in a syngeneic mouse model. J Transl Med 2017; 15:58. [PMID: 28298211 PMCID: PMC5353897 DOI: 10.1186/s12967-017-1158-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/06/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Malignant mesothelioma (MM) is a very aggressive type of cancer, with a dismal prognosis and inherent resistance to chemotherapeutics. Development and evaluation of new therapeutic approaches is highly needed. Immunosuppressant FTY720, approved for multiple sclerosis treatment, has recently raised attention for its anti-tumor activity in a variety of cancers. However, its therapeutic potential in MM has not been evaluated yet. METHODS Cell viability and anchorage-independent growth were evaluated in a panel of MM cell lines and human mesothelial cells (HM) upon FTY720 treatment to assess in vitro anti-tumor efficacy. The mechanism of action of FTY720 in MM was assessed by measuring the activity of phosphatase protein 2A (PP2A)-a major target of FTY720. The binding of the endogenous inhibitor SET to PP2A in presence of FTY720 was evaluated by immunoblotting and immunoprecipitation. Signaling and activation of programmed cell death were evaluated by immunoblotting and flow cytometry. A syngeneic mouse model was used to evaluate anti-tumor efficacy and toxicity profile of FTY720 in vivo. RESULTS We show that FTY720 significantly suppressed MM cell viability and anchorage-independent growth without affecting normal HM cells. FTY720 inhibited the phosphatase activity of PP2A by displacement of SET protein, which appeared overexpressed in MM, as compared to HM cells. FTY720 promoted AKT dephosphorylation and Bcl-2 degradation, leading to induction of programmed cell death, as demonstrated by caspase-3 and PARP activation, as well as by cytochrome c and AIF intracellular translocation. Moreover, FTY720 administration in vivo effectively reduced tumor burden in mice without apparent toxicity. CONCLUSIONS Our preclinical data indicate that FTY720 is a potentially promising therapeutic agent for MM treatment.
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Affiliation(s)
- Agata Szymiczek
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Sandra Pastorino
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA.
| | - David Larson
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Mika Tanji
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Laura Pellegrini
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Jiaming Xue
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Shuangjing Li
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Carlotta Giorgi
- Department of Morphology-Surgery-Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Morphology-Surgery-Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Yasutaka Takinishi
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Harvey I Pass
- Department of Cardiothoracic Surgery, New York University Langone Medical Center, New York, NY, 10065, USA
| | - Hideki Furuya
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Giovanni Gaudino
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Andrea Napolitano
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA
| | - Michele Carbone
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA.
| | - Haining Yang
- Thoracic Oncology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, 96813, USA.
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Lee SY, Lee YY, Choi JS, Yoon MS, Han JS. Phosphatidic acid induces decidualization by stimulating Akt-PP2A binding in human endometrial stromal cells. FEBS J 2016; 283:4163-4175. [PMID: 27696687 DOI: 10.1111/febs.13914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 09/29/2016] [Indexed: 12/19/2022]
Abstract
Decidualization of human endometrial stromal cells (hESCs) is crucial for successful uterine implantation and maintaining pregnancy. We previously reported that phospholipase D1 (PLD1) is required for cAMP-induced decidualization of hESCs. However, the mechanism by which phosphatidic acid (PA), the product of PLD1 action, might regulate decidualization is not known. We confirmed that PA induced decidualization of hESCs by observing morphological changes and measuring increased levels of decidualization markers such as IGFBP1 and prolactin transcripts (P < 0.05). Treatment with PA reduced phosphorylation of Akt and consequently that of FoxO1, which led to the increased IGFBP1 and prolactin mRNA levels (P < 0.05). Conversely, PLD1 knockdown rescued Akt phosphorylation. Binding of PP2A and Akt increased in response to cAMP or PA, suggesting that their binding is directly responsible for the inactivation of Akt during decidualization. Consistent with this observation, treatment with okadaic acid, a PP2A inhibitor, also inhibited cAMP-induced decidualization by blocking Akt dephosphorylation.
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Affiliation(s)
- So Young Lee
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea
| | - Yun Young Lee
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea
| | - Joong Sub Choi
- Department of Obstetrics and Gynecology, College of Medicine, Hanyang University, Seoul, Korea
| | - Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, Korea
| | - Joong-Soo Han
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.,Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul, Korea
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Heiser K, Nicholas C, Garcea RL. Activation of DNA damage repair pathways by murine polyomavirus. Virology 2016; 497:346-356. [PMID: 27529739 DOI: 10.1016/j.virol.2016.07.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/08/2016] [Accepted: 07/26/2016] [Indexed: 11/27/2022]
Abstract
Nuclear replication of DNA viruses activates DNA damage repair (DDR) pathways, which are thought to detect and inhibit viral replication. However, many DNA viruses also depend on these pathways in order to optimally replicate their genomes. We investigated the relationship between murine polyomavirus (MuPyV) and components of DDR signaling pathways including CHK1, CHK2, H2AX, ATR, and DNAPK. We found that recruitment and retention of DDR proteins at viral replication centers was independent of H2AX, as well as the viral small and middle T-antigens. Additionally, infectious virus production required ATR kinase activity, but was independent of CHK1, CHK2, or DNAPK signaling. ATR inhibition did not reduce the total amount of viral DNA accumulated, but affected the amount of virus produced, indicating a defect in virus assembly. These results suggest that MuPyV may utilize a subset of DDR proteins or non-canonical DDR signaling pathways in order to efficiently replicate and assemble.
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Affiliation(s)
- Katie Heiser
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado at Boulder, Jennie Smoly Caruthers Biotechnology Building, 3415 Colorado Avenue, Boulder, CO 80303, USA
| | - Catherine Nicholas
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado at Boulder, Jennie Smoly Caruthers Biotechnology Building, 3415 Colorado Avenue, Boulder, CO 80303, USA
| | - Robert L Garcea
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado at Boulder, Jennie Smoly Caruthers Biotechnology Building, 3415 Colorado Avenue, Boulder, CO 80303, USA.
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Cancerous Inhibitor of PP2A Silencing Inhibits Proliferation and Promotes Apoptosis in Human Multiple Myeloma Cells. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6864135. [PMID: 27144172 PMCID: PMC4837246 DOI: 10.1155/2016/6864135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/13/2016] [Accepted: 03/20/2016] [Indexed: 12/11/2022]
Abstract
Multiple myeloma is the second most prevalent type of blood cancer, representing approximately 1% of all cancers and 2% of all cancer deaths. There is therefore a strong need to identify critical targets in multiple myeloma neoplasia and progression. Cancerous inhibitor of PP2A (CIP2A) is a human oncoprotein that regulates cancer cell viability and anchorage-independent growth and induces apoptosis. The present study investigated CIP2A function in the human multiple myeloma cell lines RPMI-8226 and NCI-H929 to determine whether it can serve as a potential therapeutic target. CIP2A was silenced in the cells by transfection of short interfering RNA and cell proliferation and apoptosis were evaluated by a tetrazolium salt-based assay and flow cytometry, respectively. CIP2A knockdown inhibited proliferation and induced apoptosis in RPMI-8226 and NCI-H929 cells and decreased the phosphorylation of phosphoinositide 3-kinase (PI3K) p85, AKT1, and mammalian target of rapamycin (mTOR) without affecting total protein levels. Treatment of CIP2A-depletion cells with insulin-like growth factor 1 decreased the effects of CIP2A inhibition on cell viability and apoptosis. These results indicate that CIP2A modulates myeloma cell proliferation and apoptosis via PI3K/AKT/mTOR signaling and suggest that it can potentially serve as a drug target for the treatment of multiple myeloma.
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Pusey M, Bail S, Xu Y, Buiakova O, Nestor M, Yang JJ, Rice LM. Inhibition of protein methylesterase 1 decreased cancerous phenotypes in endometrial adenocarcinoma cell lines and xenograft tumor models. Tumour Biol 2016; 37:11835-11842. [PMID: 27048286 DOI: 10.1007/s13277-016-5036-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/28/2016] [Indexed: 12/15/2022] Open
Abstract
Protein methylesterase 1 (PME-1) promotes cancerous phenotypes through the demethylation and inactivation of protein phosphatase 2A. We previously demonstrated that PME-1 overexpression promotes Akt, ERK, and may promote Wnt signaling and increases tumor burden in a xenograft model of endometrial cancer. Here, we show that covalent PME-1 inhibitors decrease cell proliferation and invasive growth in vitro but have no effect in vivo at the concentrations tested; however, depletion of PME-1 with shRNA in an endometrial cancer xenograft model significantly reduced tumor growth. Thus, discovery of more potent PME-1 inhibitors may be beneficial for the treatment of endometrial cancer.
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Affiliation(s)
- Michelle Pusey
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA
| | - Sophie Bail
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA
| | - Yan Xu
- Invivotek, LLC, 16 Black Forest Road, Hamilton, NJ, 08691, USA
| | - Olesia Buiakova
- Invivotek, LLC, 16 Black Forest Road, Hamilton, NJ, 08691, USA
| | - Mariya Nestor
- Pathology Department, Members of Genesis Biotechnology Group, LLC, Medical Diagnostic Laboratories LLC, 2439 Kuser Road, Hamilton, NJ, 08690, USA
| | - Jing-Jing Yang
- Pathology Department, Members of Genesis Biotechnology Group, LLC, Medical Diagnostic Laboratories LLC, 2439 Kuser Road, Hamilton, NJ, 08690, USA
| | - Lyndi M Rice
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA.
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Vera J, Lartigue L, Vigneron S, Gadea G, Gire V, Del Rio M, Soubeyran I, Chibon F, Lorca T, Castro A. Greatwall promotes cell transformation by hyperactivating AKT in human malignancies. eLife 2015; 4. [PMID: 26613407 PMCID: PMC4733044 DOI: 10.7554/elife.10115] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/26/2015] [Indexed: 12/25/2022] Open
Abstract
The PP2A phosphatase is often inactivated in cancer and is considered as a tumour suppressor. A new pathway controlling PP2A activity in mitosis has been recently described. This pathway includes the Greatwall (GWL) kinase and its substrates endosulfines. At mitotic entry, GWL is activated and phosphorylates endosulfines that then bind and inhibit PP2A. We analysed whether GWL overexpression could participate in cancer development. We show that GWL overexpression promotes cell transformation and increases invasive capacities of cells through hyperphosphorylation of the oncogenic kinase AKT. Interestingly, AKT hyperphosphorylation induced by GWL is independent of endosulfines. Rather, GWL induces GSK3 kinase dephosphorylation in its inhibitory sites and subsequent SCF-dependent degradation of the PHLPP phosphatase responsible for AKT dephosphorylation. In line with its oncogenic activity, we find that GWL is often overexpressed in human colorectal tumoral tissues. Thus, GWL is a human oncoprotein that promotes the hyperactivation of AKT via the degradation of its phosphatase, PHLPP, in human malignancies.
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Affiliation(s)
- Jorge Vera
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
| | - Lydia Lartigue
- Department of Medical Oncology, Institut Bergonié, Institut National de la Santé et de la Recherche Medicale, Université Bordeaux Segalen, Bordeux, France
| | - Suzanne Vigneron
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
| | - Gilles Gadea
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
| | - Veronique Gire
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
| | - Maguy Del Rio
- Institut de Recherche en Cancérologie de Montpellier, Université de Montpellier, Montpellier, France
| | - Isabelle Soubeyran
- Department of Medical Oncology, Institut Bergonié, Institut National de la Santé et de la Recherche Medicale, Université Bordeaux Segalen, Bordeux, France
| | - Frederic Chibon
- Department of Medical Oncology, Institut Bergonié, Institut National de la Santé et de la Recherche Medicale, Université Bordeaux Segalen, Bordeux, France
| | - Thierry Lorca
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
| | - Anna Castro
- Centre de Recherche de Biochimie Macromoléculaire, Université de Montpellier, Montpellier, France
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Park B, Je YT, Chun KH. Akt is translocated to the mitochondria during etoposide-induced apoptosis of HeLa cells. Mol Med Rep 2015; 12:7577-81. [PMID: 26458825 DOI: 10.3892/mmr.2015.4378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 09/03/2015] [Indexed: 11/05/2022] Open
Abstract
Akt, or protein kinase B, is a key serine-threonine kinase, which exerts anti-apoptotic effects and promotes cell proliferation in response to various stimuli. Recently, however, it was demonstrated that Akt exhibits a proapoptotic role in certain contexts. During etoposide‑induced apoptosis of HeLa cells, Akt enhances the interaction of second mitochondria‑derived activator of caspases/direct IAP binding protein with low pI (Smac/DIABLO) and X‑linked inhibitor of apoptosis protein by phosphorylating Smac at serine 67, and thus promotes apoptosis. However, the detailed mechanisms underlying Akt regulation in etoposide‑mediated apoptosis remain to be determined. The present study investigated whether etoposide triggers the translocation of Akt into the mitochondria. It was found that Akt activity was increased and sustained during apoptosis triggered by etoposide in HeLa cells. During apoptosis, Akt was translocated from the cytoplasm into the mitochondria in a phosphoinositide 3‑kinase-dependent manner at the early and late stages of apoptosis. Concomitantly, the depletion of Akt in the nuclear fraction was observed after etoposide treatment from analysis of confocal microscopy. The results suggest that etoposide‑stimulated Akt is translocated into the mitochondria, thereby possibly enhancing its interaction with Smac and promoting apoptosis in HeLa cells. These results indicate that Akt may be a promising candidate for a pro-apoptotic approach in cancer treatment.
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Affiliation(s)
- Byoungduck Park
- College of Pharmacy, Keimyung University, Daegu 42601, Republic of Korea
| | - Young-Tae Je
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kwang-Hoon Chun
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea
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Nguyen LK, Matallanas DG, Romano D, Kholodenko BN, Kolch W. Competing to coordinate cell fate decisions: the MST2-Raf-1 signaling device. Cell Cycle 2015; 14:189-99. [PMID: 25607644 PMCID: PMC4353221 DOI: 10.4161/15384101.2014.973743] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
How do biochemical signaling pathways generate biological specificity? This question is fundamental to modern biology, and its enigma has been accentuated by the discovery that most proteins in signaling networks serve multifunctional roles. An answer to this question may lie in analyzing network properties rather than individual traits of proteins in order to elucidate design principles of biochemical networks that enable biological decision-making. We discuss how this is achieved in the MST2/Hippo-Raf-1 signaling network with the help of mathematical modeling and model-based analysis, which showed that competing protein interactions with affinities controlled by dynamic protein modifications can function as Boolean computing devices that determine cell fate decisions. In addition, we discuss areas of interest for future research and highlight how systems approaches would be of benefit.
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Affiliation(s)
- Lan K Nguyen
- a Systems Biology Ireland ; University College Dublin ; Belfield , Dublin , Ireland
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38
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Kauko O, Laajala TD, Jumppanen M, Hintsanen P, Suni V, Haapaniemi P, Corthals G, Aittokallio T, Westermarck J, Imanishi SY. Label-free quantitative phosphoproteomics with novel pairwise abundance normalization reveals synergistic RAS and CIP2A signaling. Sci Rep 2015; 5:13099. [PMID: 26278961 PMCID: PMC4642524 DOI: 10.1038/srep13099] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 07/06/2015] [Indexed: 11/11/2022] Open
Abstract
Hyperactivated RAS drives progression of many human malignancies. However, oncogenic activity of RAS is dependent on simultaneous inactivation of protein phosphatase 2A (PP2A) activity. Although PP2A is known to regulate some of the RAS effector pathways, it has not been systematically assessed how these proteins functionally interact. Here we have analyzed phosphoproteomes regulated by either RAS or PP2A, by phosphopeptide enrichment followed by mass-spectrometry-based label-free quantification. To allow data normalization in situations where depletion of RAS or PP2A inhibitor CIP2A causes a large uni-directional change in the phosphopeptide abundance, we developed a novel normalization strategy, named pairwise normalization. This normalization is based on adjusting phosphopeptide abundances measured before and after the enrichment. The superior performance of the pairwise normalization was verified by various independent methods. Additionally, we demonstrate how the selected normalization method influences the downstream analyses and interpretation of pathway activities. Consequently, bioinformatics analysis of RAS and CIP2A regulated phosphoproteomes revealed a significant overlap in their functional pathways. This is most likely biologically meaningful as we observed a synergistic survival effect between CIP2A and RAS expression as well as KRAS activating mutations in TCGA pan-cancer data set, and synergistic relationship between CIP2A and KRAS depletion in colony growth assays.
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Affiliation(s)
- Otto Kauko
- 1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland [2] Department of Pathology, University of Turku, FI-20520 Turku, Finland [3] Turku Doctoral Program of Biomedical Sciences (TuBS), Turku, Finland
| | - Teemu Daniel Laajala
- 1] Department of Mathematics and Statistics, University of Turku, FI-20014 Turku, Finland [2] Drug Research Doctoral Programme (DRDP), Turku, Finland
| | - Mikael Jumppanen
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland
| | - Petteri Hintsanen
- Institute for Molecular Medicine Finland, Tukholmankatu 8, FI-00290 Helsinki, Finland
| | - Veronika Suni
- 1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland [2] Turku Centre for Computer Science, FI-20520 Turku, Finland
| | - Pekka Haapaniemi
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland
| | - Garry Corthals
- 1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland [2] Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland, Tukholmankatu 8, FI-00290 Helsinki, Finland
| | - Jukka Westermarck
- 1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland [2] Department of Pathology, University of Turku, FI-20520 Turku, Finland
| | - Susumu Y Imanishi
- 1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistokatu 6, FI-20520 Turku, Finland [2] Faculty of Pharmacy, Meijo University, Yagotoyama 150, Tempaku, Nagoya 468-8503, Japan
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Lv P, Wang Y, Ma J, Wang Z, Li JL, Hong CS, Zhuang Z, Zeng YX. Inhibition of protein phosphatase 2A with a small molecule LB100 radiosensitizes nasopharyngeal carcinoma xenografts by inducing mitotic catastrophe and blocking DNA damage repair. Oncotarget 2015; 5:7512-24. [PMID: 25245035 PMCID: PMC4202140 DOI: 10.18632/oncotarget.2258] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nasopharyngeal carcinoma (NPC), while uncommon worldwide, is a major health problem in China. Although local radiation and surgery provide good control of NPC, better treatments that permit reductions in radiation dosing are needed. Inhibition of protein phosphatase 2A (PP2A), a ubiquitous multifunctional enzyme with critical roles in cell cycle regulation and DNA-damage response, reportedly sensitizes cancer cells to radiation and chemotherapy. We studied PP2A inhibition with LB100, a small molecule currently in a Phase I clinical trial, on radiosensitization of two human nasopharyngeal cell lines: CNE1, which is reportedly radioresistant, and CNE2. In both cell lines, LB100 exposure increased intracellular p-Plk1, TCTP, and Cdk1 and decreased p53, changes associated with cell cycle arrest, mitotic catastrophe and radio-inhibition of cell proliferation. Mice bearing subcutaneous xenografts of either cell line were administered 1.5 mg/kg LB100 daily for three days and a single dose of 20 Gy radiation (day 3), which produced marked and prolonged tumor mass regression (dose enhancement factors of 2.98 and 2.27 for CNE1 and CNE2 xenografts, respectively). Treatment with either LB100 or radiation alone only transiently inhibited xenograft growth. Our results support further exploration of PP2A inhibition as part of radiotherapy regimens for NPC and potentially other solid tumors.
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Affiliation(s)
- Peng Lv
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences (CAMS) ,Beijing , People's Republic of China. Beijing Neurosurgical Institute, Capital Medical University, Beijing, People's Republic of China
| | - Yue Wang
- Institute for Medical Device Standardization Administration, National Institutes for Food and Drug Control, Beijing , People's Republic of China
| | - Jie Ma
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences (CAMS) ,Beijing , People's Republic of China
| | - Zheng Wang
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences (CAMS) ,Beijing , People's Republic of China
| | - Jing-Li Li
- Institute for Medical Device Standardization Administration, National Institutes for Food and Drug Control, Beijing , People's Republic of China
| | - Christopher S Hong
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD ,USA
| | - Zhengping Zhuang
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD ,USA
| | - Yi-Xin Zeng
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences (CAMS) ,Beijing , People's Republic of China. Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong , People's Republic of China. State Key Laboratory of Oncology in Southern China, Guangzhou, Guangdong , People's Republic of China
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40
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Kiely M, Kiely PA. PP2A: The Wolf in Sheep's Clothing? Cancers (Basel) 2015; 7:648-69. [PMID: 25867001 PMCID: PMC4491676 DOI: 10.3390/cancers7020648] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/16/2015] [Accepted: 03/23/2015] [Indexed: 12/21/2022] Open
Abstract
Protein Phosphatase 2A (PP2A) is a major serine/threonine phosphatase in cells. It consists of a catalytic subunit (C), a structural subunit (A), and a regulatory/variable B-type subunit. PP2A has a critical role to play in homeostasis where its predominant function is as a phosphatase that regulates the major cell signaling pathways in cells. Changes in the assembly, activity and substrate specificity of the PP2A holoenzyme have a direct role in disease and are a major contributor to the maintenance of the transformed phenotype in cancer. We have learned a lot about how PP2A functions from specific mutations that disrupt the core assembly of PP2A and from viral proteins that target PP2A and inhibit its effect as a phosphatase. This prompted various studies revealing that restoration of PP2A activity benefits some cancer patients. However, our understanding of the mechanism of action of this is limited because of the complex nature of PP2A holoenzyme assembly and because it acts through a wide variety of signaling pathways. Information on PP2A is also conflicting as there are situations whereby inactivation of PP2A induces apoptosis in many cancer cells. In this review we discuss this relationship and we also address many of the pertinent and topical questions that relate to novel therapeutic strategies aimed at altering PP2A activity.
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Affiliation(s)
- Maeve Kiely
- Department of Life Sciences, and Materials and Surface Science Institute, University of Limerick, Limerick 78666, Ireland.
| | - Patrick A Kiely
- Department of Life Sciences, and Materials and Surface Science Institute, University of Limerick, Limerick 78666, Ireland.
- Stokes Institute, University of Limerick 78666, Limerick, Ireland.
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Ciccone M, Calin GA, Perrotti D. From the Biology of PP2A to the PADs for Therapy of Hematologic Malignancies. Front Oncol 2015; 5:21. [PMID: 25763353 PMCID: PMC4329809 DOI: 10.3389/fonc.2015.00021] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 01/16/2015] [Indexed: 11/13/2022] Open
Abstract
Over the past decades, an emerging role of phosphatases in the pathogenesis of hematologic malignancies and solid tumors has been established. The tumor-suppressor protein phosphatase 2A (PP2A) belongs to the serine-threonine phosphatases family and accounts for the majority of serine-threonine phosphatase activity in eukaryotic cells. Numerous studies have shown that inhibition of PP2A expression and/or function may contribute to leukemogenesis in several hematological malignancies. Likewise, overexpression or aberrant expression of physiologic PP2A inhibitory molecules (e.g., SET and its associated SETBP1 and CIP2A) may turn off PP2A function and participate to leukemic progression. The discovery of PP2A as tumor suppressor has prompted the evaluation of the safety and the efficacy of new compounds, which can restore PP2A activity in leukemic cells. Although further studies are needed to better understand how PP2A acts in the intricate phosphatases/kinases cancer network, the results reviewed herein strongly support the development on new PP2A-activating drugs and the immediate introduction of those available into clinical protocols for leukemia patients refractory or resistant to current available therapies.
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Affiliation(s)
- Maria Ciccone
- Department of Experimental Therapeutics, MD Anderson Cancer Center, The University of Texas , Houston, TX , USA
| | - George A Calin
- Department of Experimental Therapeutics, MD Anderson Cancer Center, The University of Texas , Houston, TX , USA
| | - Danilo Perrotti
- Department of Medicine, The Greenebaum Cancer Center, University of Maryland School of Medicine , Baltimore, MD , USA
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42
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Flørenes VA, Emilsen E, Dong HP, Førsund M, Holm R, Slipicevic A. Cellular localization of CIP2A determines its prognostic impact in superficial spreading and nodular melanoma. Cancer Med 2015; 4:903-13. [PMID: 25663244 PMCID: PMC4472213 DOI: 10.1002/cam4.425] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 12/15/2014] [Accepted: 12/23/2014] [Indexed: 01/31/2023] Open
Abstract
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an important oncogene contributing to cancer progression partially by regulating cMYC and AKT. We examined CIP2A expression in cutaneous melanomas, its association with clinicopathological parameters and mapped molecular mechanisms regulated by CIP2A in vitro. CIP2A expression was analyzed by immunohistochemistry in 17 nevi, 132 primary melanomas and 49 metastases. Effects of siRNA-mediated down-regulation on proliferation, apoptosis and signaling pathways were assessed in melanoma cell lines. In superficial spreading melanomas (SSM), high nuclear CIP2A expression was associated with poor overall survival (OS) (P = 0.0018). Surprisingly, high cytoplasmic expression was related to improved relapse-free (P = 0.031) and OS (P = 0.014) in nodular melanomas (NM). In vitro experiments revealed that CIP2A can regulate proliferation and/or apoptosis partially through the PI3K/AKT pathway but also independently. In summary, CIP2A could represent a potential therapeutic target in SSM. However, in NM cytoplasmic CIP2A is associated with improved prognosis indicating that CIP2A has distinct, complex functions dependent on the molecular context and histological subtype. As seen in other cancer types, CIP2A can influence cMYC and AKT, but our data also suggest that in melanoma it has additional targets which need to be identified.
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Affiliation(s)
- Vivi Ann Flørenes
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
| | - Elisabeth Emilsen
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
| | - Hiep Phuc Dong
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
| | - Mette Førsund
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
| | - Ruth Holm
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
| | - Ana Slipicevic
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, N-0310, Oslo, Norway
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43
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Zhu DW, Yuan YX, Qiao JK, Yu C, Yang X, Wang LZ, Zhang ZY, Zhong LP. Enhanced anticancer activity of a protein phosphatase 2A inhibitor on chemotherapy and radiation in head and neck squamous cell carcinoma. Cancer Lett 2014; 356:773-80. [PMID: 25449438 DOI: 10.1016/j.canlet.2014.10.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 10/23/2014] [Accepted: 10/23/2014] [Indexed: 11/18/2022]
Abstract
The aim of this study is to eliminate more cancer cells by promoting them from quiescence into cell cycle or by changing their molecular events, leading them to be sensitive to radiation or chemotherapy. Protein phosphatase 2A plays an important role in many cellular functions and regulates various biological processes. It is unclear that LB1, which is an inhibitor of protein phosphatase 2A, has enhanced anticancer activity on chemotherapy (cisplatin and 5-fluorourcil) and radiation in head and neck squamous cell carcinoma (HNSCC). Herein, we performed both in vitro and in vivo studies to determine the anticancer activity of LB1 on chemotherapy and radiation in HNSCC, with detection of p53 expression, AKT and MDM2 phosphorylation. In vitro studies indicated that, LB1 could significantly enhance the cytotoxicity of cisplatin, 5-fluorourcil, and radiation; LB1 could also significantly enhance the treatment effect of cisplatin in nude mice. The anticancer activity of LB1 was mediated by increased AKT phosphorylation and decreased p53 expression with increased MDM2 phosphorylation, especially when combined with cisplatin. Our data suggest a strategy of improving treatment effect through the enhanced anticancer activity of LB1 on cisplatin-based chemotherapy and radiation in HNSCC.
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Affiliation(s)
- Dong-wang Zhu
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yong-xiang Yuan
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin-ke Qiao
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cong Yu
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi Yang
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li-zhen Wang
- Department of Oral Pathology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhi-yuan Zhang
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lai-ping Zhong
- Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Li T, Wang G. Computer-aided targeting of the PI3K/Akt/mTOR pathway: toxicity reduction and therapeutic opportunities. Int J Mol Sci 2014; 15:18856-91. [PMID: 25334061 PMCID: PMC4227251 DOI: 10.3390/ijms151018856] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/21/2014] [Accepted: 10/08/2014] [Indexed: 12/14/2022] Open
Abstract
The PI3K/Akt/mTOR pathway plays an essential role in a wide range of biological functions, including metabolism, macromolecular synthesis, cell growth, proliferation and survival. Its versatility, however, makes it a conspicuous target of many pathogens; and the consequential deregulations of this pathway often lead to complications, such as tumorigenesis, type 2 diabetes and cardiovascular diseases. Molecular targeted therapy, aimed at modulating the deregulated pathway, holds great promise for controlling these diseases, though side effects may be inevitable, given the ubiquity of the pathway in cell functions. Here, we review a variety of factors found to modulate the PI3K/Akt/mTOR pathway, including gene mutations, certain metabolites, inflammatory factors, chemical toxicants, drugs found to rectify the pathway, as well as viruses that hijack the pathway for their own synthetic purposes. Furthermore, this evidence of PI3K/Akt/mTOR pathway alteration and related pathogenesis has inspired the exploration of computer-aided targeting of this pathway to optimize therapeutic strategies. Herein, we discuss several possible options, using computer-aided targeting, to reduce the toxicity of molecularly-targeted therapy, including mathematical modeling, to reveal system-level control mechanisms and to confer a low-dosage combination therapy, the potential of PP2A as a therapeutic target, the formulation of parameters to identify patients who would most benefit from specific targeted therapies and molecular dynamics simulations and docking studies to discover drugs that are isoform specific or mutation selective so as to avoid undesired broad inhibitions. We hope this review will stimulate novel ideas for pharmaceutical discovery and deepen our understanding of curability and toxicity by targeting the PI3K/Akt/mTOR pathway.
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Affiliation(s)
- Tan Li
- Department of Biology, South University of Science and Technology of China, 1088 Xueyuan Rd., Shenzhen 518055, China.
| | - Guanyu Wang
- Department of Biology, South University of Science and Technology of China, 1088 Xueyuan Rd., Shenzhen 518055, China.
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45
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Polyomavirus small T antigen interacts with yes-associated protein to regulate cell survival and differentiation. J Virol 2014; 88:12055-64. [PMID: 25122798 DOI: 10.1128/jvi.01399-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Murine polyomavirus small t antigen (PyST) regulates cell cycle, cell survival, apoptosis, and differentiation and cooperates with middle T antigen (MT) to transform primary cells in vitro and in vivo. Like all polyomavirus T antigens, PyST functions largely via its interactions with host cell proteins. Here, we show that PyST binds both Yes-associated protein 1 (YAP1) and YAP2, integral parts of the Hippo signaling pathway, which is a subject of increasing interest in human cancer. The transcription factor TEAD, which is a known target of YAP, is also found in PyST complexes. PyST enhanced YAP association with protein phosphatase 2A (PP2A), leading to decreased YAP phosphorylation. PyST increased YAP levels by decreasing its degradation. This effect was mediated by a reduction in YAP association with β-transducin repeat protein (βTRCP), which is known to regulate YAP turnover in a phosphorylation-dependent manner. Genetic analysis has identified PyST mutants defective in YAP binding. These mutants demonstrated that YAP binding is important for PyST to block myoblast differentiation and to synergize with the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) to promote cell death in 3T3-L1 preadipocytes placed under differentiation conditions. In addition to YAP binding, both of these phenotypes require PyST binding to PP2A. Importance: The Hippo/YAP pathway is a highly conserved cascade important for tissue development and homeostasis. Defects in this pathway are increasingly being associated with cancer. Polyomavirus small t antigen is a viral oncogene that cooperates with middle T antigen in transformation. On its own, small t antigen controls cell survival and differentiation. By binding YAP, small t antigen brings it together with protein phosphatase 2A. This work shows how this association of small t antigen with YAP is important for its effects on cell phenotype. It also suggests that PyST can be used to characterize cellular processes that are regulated by YAP.
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46
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Pores Fernando AT, Andrabi S, Cizmecioglu O, Zhu C, Livingston DM, Higgins JMG, Schaffhausen BS, Roberts TM. Polyoma small T antigen triggers cell death via mitotic catastrophe. Oncogene 2014; 34:2483-92. [PMID: 24998850 PMCID: PMC4286542 DOI: 10.1038/onc.2014.192] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 05/16/2014] [Accepted: 05/28/2014] [Indexed: 12/25/2022]
Abstract
Polyoma small T antigen (PyST), an early gene product of the polyoma virus, has been shown to cause cell death in a number of mammalian cells in a protein phosphatase 2A (PP2A)-dependent manner. In the current study, using a cell line featuring regulated expression of PyST, we found that PyST arrests cells in mitosis. Live-cell and immunofluorescence studies showed that the majority of the PyST expressing cells were arrested in prometaphase with almost no cells progressing beyond metaphase. These cells exhibited defects in chromosomal congression, sister chromatid cohesion and spindle positioning, thereby resulting in the activation of the spindle assembly checkpoint. Prolonged mitotic arrest then led to cell death via mitotic catastrophe. Cell cycle inhibitors that block cells in G1/S prevented PyST-induced death. PyST-induced cell death that occurs during M is not dependent on p53 status. These data suggested, and our results confirmed, that PP2A inhibition could be used to preferentially kill cancer cells with p53 mutations that proliferate normally in the presence of cell cycle inhibitors.
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Affiliation(s)
- A T Pores Fernando
- 1] Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA [2] Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - S Andrabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - O Cizmecioglu
- 1] Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA [2] Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - C Zhu
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA
| | - D M Livingston
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - J M G Higgins
- 1] Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA [2] Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, UK
| | - B S Schaffhausen
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, USA
| | - T M Roberts
- 1] Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA [2] Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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47
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Suppression of antifolate resistance by targeting the myosin Va trafficking pathway in melanoma. Neoplasia 2014; 15:826-39. [PMID: 23814494 DOI: 10.1593/neo.13320] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 04/10/2013] [Accepted: 04/11/2013] [Indexed: 01/01/2023] Open
Abstract
Human melanoma is a significant clinical problem. As most melanoma patients relapse with lethal drug-resistant disease, understanding and preventing mechanism(s) of resistance is one of the highest priorities to improve melanoma therapy. Melanosomal sequestration and the cellular exportation of cytotoxic drugs have been proposed to be important melanoma-specific mechanisms that contribute to multidrug resistance in melanoma. Concretely, we found that treatment of melanoma with methotrexate (MTX) altered melanogenesis and accelerated the exportation of melanosomes; however, the cellular and molecular processes by which MTX is trapped into melanosomes and exported out of cells have not been elucidated. In this study, we identified myosin Va (MyoVa) as a possible mediator of these cellular processes. The results demonstrated that melanoma treatment with MTX leads to Akt2-dependent MyoVa phosphorylation, which enhances its ability to interact with melanosomes and accelerates their exportation. To understand the mechanism(s) by which MTX activates Akt2, we examined the effects of this drug on the activity of protein phosphatase 2A, an Akt inhibitor activated by the methylation of its catalytic subunit. Taken together, this study identified a novel trafficking pathway in melanoma that promotes tumor resistance through Akt2/MyoVa activation. Because of these findings, we explored several MTX combination therapies to increase the susceptibility of melanoma to this drug. By avoiding MTX exportation, we observed that the E2F1 apoptotic pathway is functional in melanoma, and its induction activates p73 and apoptosis protease-activating factor 1 following a p53-autonomous proapoptotic signaling event.
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48
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Khanna A, Pimanda JE, Westermarck J. Cancerous Inhibitor of Protein Phosphatase 2A, an Emerging Human Oncoprotein and a Potential Cancer Therapy Target. Cancer Res 2013; 73:6548-53. [DOI: 10.1158/0008-5472.can-13-1994] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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49
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Fan YL, Chen L, Wang J, Yao Q, Wan JQ. Over expression of PPP2R2C inhibits human glioma cells growth through the suppression of mTOR pathway. FEBS Lett 2013; 587:3892-7. [PMID: 24126060 DOI: 10.1016/j.febslet.2013.09.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/28/2013] [Accepted: 09/17/2013] [Indexed: 11/29/2022]
Abstract
PPP2R2C encodes a gamma isoform of the subunit B55 subfamily, which is a regulatory subunit of Protein phosphatase type 2A (PP2A). Our study shows that PPP2R2C is downregulated in glioma cells and human brain cancer patient samples. Overexpression of PPP2R2C inhibited cancer cell proliferation both in vitro and in vivo through the suppression of the activity of S6K in the mTOR pathway. Moreover, exogenous expression of PPP2R2C promoted the formation of a complex with the PP2A-C subunit to further enhance the binding of PP2A-C with S6K. Our results suggest that PPP2R2C is a potential tumor suppressor gene in human brain cancers. This study will provide novel insight into the development of therapeutic strategies in the treatment of human brain tumors.
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Affiliation(s)
- Yi-Ling Fan
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
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50
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Simon BR, Parlee SD, Learman BS, Mori H, Scheller EL, Cawthorn WP, Ning X, Gallagher K, Tyrberg B, Assadi-Porter FM, Evans CR, MacDougald OA. Artificial sweeteners stimulate adipogenesis and suppress lipolysis independently of sweet taste receptors. J Biol Chem 2013; 288:32475-32489. [PMID: 24068707 DOI: 10.1074/jbc.m113.514034] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
G protein-coupled receptors mediate responses to a myriad of ligands, some of which regulate adipocyte differentiation and metabolism. The sweet taste receptors T1R2 and T1R3 are G protein-coupled receptors that function as carbohydrate sensors in taste buds, gut, and pancreas. Here we report that sweet taste receptors T1R2 and T1R3 are expressed throughout adipogenesis and in adipose tissues. Treatment of mouse and human precursor cells with artificial sweeteners, saccharin and acesulfame potassium, enhanced adipogenesis. Saccharin treatment of 3T3-L1 cells and primary mesenchymal stem cells rapidly stimulated phosphorylation of Akt and downstream targets with functions in adipogenesis such as cAMP-response element-binding protein and FOXO1; however, increased expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α was not observed until relatively late in differentiation. Saccharin-stimulated Akt phosphorylation at Thr-308 occurred within 5 min, was phosphatidylinositol 3-kinase-dependent, and occurred in the presence of high concentrations of insulin and dexamethasone; phosphorylation of Ser-473 occurred more gradually. Surprisingly, neither saccharin-stimulated adipogenesis nor Thr-308 phosphorylation was dependent on expression of T1R2 and/or T1R3, although Ser-473 phosphorylation was impaired in T1R2/T1R3 double knock-out precursors. In mature adipocytes, artificial sweetener treatment suppressed lipolysis even in the presence of forskolin, and lipolytic responses were correlated with phosphorylation of hormone-sensitive lipase. Suppression of lipolysis by saccharin in adipocytes was also independent of T1R2 and T1R3. These results suggest that some artificial sweeteners have previously uncharacterized metabolic effects on adipocyte differentiation and metabolism and that effects of artificial sweeteners on adipose tissue biology may be largely independent of the classical sweet taste receptors, T1R2 and T1R3.
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Affiliation(s)
| | | | | | | | | | - William P Cawthorn
- Departments of Molecular and Integrative Physiology,; Musculoskeletal Research, Lilly Research Laboratories, Indianapolis, Indiana 46285
| | - Xiaomin Ning
- Departments of Molecular and Integrative Physiology
| | | | - Björn Tyrberg
- Cardiovascular and Metabolic Disease, MedImmune LLC, Gaithersburg Headquarters, Gaithersburg, Maryland 20878,; Metabolic Signaling and Disease, Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, Florida 32827
| | | | | | - Ormond A MacDougald
- From the Program in Cellular and Molecular Biology; Departments of Molecular and Integrative Physiology,; Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105,.
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