1
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Edtmayer S, Witalisz-Siepracka A, Zdársky B, Heindl K, Weiss S, Eder T, Dutta S, Graichen U, Klee S, Sharif O, Wieser R, Győrffy B, Poli V, Casanova E, Sill H, Grebien F, Stoiber D. A novel function of STAT3β in suppressing interferon response improves outcome in acute myeloid leukemia. Cell Death Dis 2024; 15:369. [PMID: 38806478 PMCID: PMC11133483 DOI: 10.1038/s41419-024-06749-9] [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: 12/14/2023] [Revised: 05/08/2024] [Accepted: 05/15/2024] [Indexed: 05/30/2024]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is frequently overexpressed in patients with acute myeloid leukemia (AML). STAT3 exists in two distinct alternatively spliced isoforms, the full-length isoform STAT3α and the C-terminally truncated isoform STAT3β. While STAT3α is predominantly described as an oncogenic driver, STAT3β has been suggested to act as a tumor suppressor. To elucidate the role of STAT3β in AML, we established a mouse model of STAT3β-deficient, MLL-AF9-driven AML. STAT3β deficiency significantly shortened survival of leukemic mice confirming its role as a tumor suppressor. Furthermore, RNA sequencing revealed enhanced STAT1 expression and interferon (IFN) signaling upon loss of STAT3β. Accordingly, STAT3β-deficient leukemia cells displayed enhanced sensitivity to blockade of IFN signaling through both an IFNAR1 blocking antibody and the JAK1/2 inhibitor Ruxolitinib. Analysis of human AML patient samples confirmed that elevated expression of IFN-inducible genes correlated with poor overall survival and low STAT3β expression. Together, our data corroborate the tumor suppressive role of STAT3β in a mouse model in vivo. Moreover, they provide evidence that its tumor suppressive function is linked to repression of the STAT1-mediated IFN response. These findings suggest that the STAT3β/α mRNA ratio is a significant prognostic marker in AML and holds crucial information for targeted treatment approaches. Patients displaying a low STAT3β/α mRNA ratio and unfavorable prognosis could benefit from therapeutic interventions directed at STAT1/IFN signaling.
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MESH Headings
- Animals
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/pathology
- Leukemia, Myeloid, Acute/metabolism
- Humans
- STAT3 Transcription Factor/metabolism
- Mice
- Signal Transduction
- Interferons/metabolism
- STAT1 Transcription Factor/metabolism
- STAT1 Transcription Factor/genetics
- Mice, Inbred C57BL
- Receptor, Interferon alpha-beta/metabolism
- Receptor, Interferon alpha-beta/genetics
- Cell Line, Tumor
- Nitriles
- Pyrazoles
- Pyrimidines
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Affiliation(s)
- Sophie Edtmayer
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Agnieszka Witalisz-Siepracka
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Bernhard Zdársky
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Kerstin Heindl
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Stefanie Weiss
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Thomas Eder
- Institute for Medical Biochemistry, University of Veterinary Medicine Vienna, Vienna, Austria
| | | | - Uwe Graichen
- Division Biostatistics and Data Science, Department of General Health Studies, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Sascha Klee
- Division Biostatistics and Data Science, Department of General Health Studies, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Omar Sharif
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Immunometabolism and Systems Biology of Obesity-Related Diseases (InSpiReD), Vienna, Austria
| | - Rotraud Wieser
- Division of Oncology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, Vienna, Austria
| | - Balázs Győrffy
- Department of Bioinformatics, Semmelweis University, Budapest, Hungary
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
- Cancer Biomarker Research Group, Institute of Molecular Life Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - Valeria Poli
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Emilio Casanova
- Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, Vienna, Austria
- Department of Pharmacology, Center of Physiology and Pharmacology & Comprehensive Cancer Center (CCC), Medical University of Vienna, Vienna, Austria
| | - Heinz Sill
- Division of Hematology, Medical University of Graz, Graz, Austria
| | - Florian Grebien
- Institute for Medical Biochemistry, University of Veterinary Medicine Vienna, Vienna, Austria
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Dagmar Stoiber
- Division Pharmacology, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, Krems, Austria.
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Marié IJ, Lahiri T, Önder Ö, Elenitoba-Johnson KS, Levy DE. Structural determinants of mitochondrial STAT3 targeting and function. MITOCHONDRIAL COMMUNICATIONS 2024; 2:1-13. [PMID: 38500969 PMCID: PMC10947224 DOI: 10.1016/j.mitoco.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Signal transducer and activator of transcription (STAT) 3 has been found within mitochondria in addition to its canonical role of shuttling between cytoplasm and nucleus during cytokine signaling. Mitochondrial STAT3 has been implicated in modulation of cellular metabolism, largely through effects on the respiratory electron transport chain. However, the structural requirements underlying mitochondrial targeting and function have remained unclear. Here, we show that mitochondrial STAT3 partitions between mitochondrial compartments defined by differential detergent solubility, suggesting that mitochondrial STAT3 is membrane associated. The majority of STAT3 was found in an SDS soluble fraction copurifying with respiratory chain proteins, including numerous components of the complex I NADH dehydrogenase, while a minor component was found with proteins of the mitochondrial translation machinery. Mitochondrial targeting of STAT3 required the amino-terminal domain, and an internal linker domain motif also directed mitochondrial translocation. However, neither the phosphorylation of serine 727 nor the presence of mitochondrial DNA was required for the mitochondrial localization of STAT3. Two cysteine residues in the STAT3 SH2 domain, which have been previously suggested to be targets for protein palmitoylation, were also not required for mitochondrial translocation, but were required for its function as an enhancer of complex I activity. These structural determinants of STAT3 mitochondrial targeting and function provide potential therapeutic targets for disrupting the activity of mitochondrial STAT3 in diseases such as cancer.
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Affiliation(s)
- Isabelle J. Marié
- Department of Pathology and Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, NY, 10128, USA
| | - Tanaya Lahiri
- Department of Pathology and Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, NY, 10128, USA
| | - Özlem Önder
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kojo S.J. Elenitoba-Johnson
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David E. Levy
- Department of Pathology and Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, NY, 10128, USA
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3
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Wu K, Sun Q, Liu D, Lu J, Wen D, Zang X, Gao L. Alternative Splicing Landscape of Head and Neck Squamous Cell Carcinoma. Technol Cancer Res Treat 2024; 23:15330338241272051. [PMID: 39113534 PMCID: PMC11307358 DOI: 10.1177/15330338241272051] [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: 11/17/2023] [Revised: 06/16/2024] [Accepted: 06/24/2024] [Indexed: 08/10/2024] Open
Abstract
Head and neck malignancies are a significant global health concern, with head and neck squamous cell carcinoma (HNSCC) being the sixth most common cancer worldwide accounting for > 90% of cases. In recent years, there has been growing recognition of the potential role of alternative splicing (AS) in the etiology of cancer. Increasing evidence suggests that AS is associated with various aspects of cancer progression, including tumor occurrence, invasion, metastasis, and drug resistance. Additionally, AS is involved in shaping the tumor microenvironment, which plays a crucial role in tumor development and response to therapy. AS can influence the expression of factors involved in angiogenesis, immune response, and extracellular matrix remodeling, all of which contribute to the formation of a supportive microenvironment for tumor growth. Exploring the mechanism of AS events in HNSCC could provide insights into the development and progression of this cancer, as well as its interaction with the tumor microenvironment. Understanding how AS contributes to the molecular changes in HNSCC cells and influences the tumor microenvironment could lead to the identification of new therapeutic targets. Targeted chemotherapy and immunotherapy strategies tailored to the specific AS patterns in HNSCC could potentially improve treatment outcomes and reduce side effects. This review explores the concept, types, processes, and technological advancements of AS, focusing on its role in the initiation, progression, treatment, and prognosis of HNSCC.
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Affiliation(s)
- Kehan Wu
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Qianhui Sun
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Dongxu Liu
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Jiayi Lu
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Deyu Wen
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Xiyan Zang
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
| | - Li Gao
- Department of Oral and Maxillofacial Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, PR China
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Arun S, Patel PK, Lakshmanan K, Rajangopal K, Swaminathan G, Byran G. Targeting STAT3 Enzyme for Cancer Treatment. Mini Rev Med Chem 2024; 24:1252-1261. [PMID: 38299278 DOI: 10.2174/0113895575254012231024062619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/03/2023] [Accepted: 09/14/2023] [Indexed: 02/02/2024]
Abstract
A category of cytoplasmic transcription factors called STATs mediates intracellular signaling, which is frequently generated at receptors on cell surfaces and subsequently sent to the nucleus. STAT3 is a member of a responsible for a variety of human tumor forms, including lymphomas, hematological malignancies, leukemias, multiple myeloma and several solid tumor types. Numerous investigations have demonstrated constitutive STAT3 activation lead to cancer development such as breast, head and neck, lung, colorectal, ovarian, gastric, hepatocellular, and prostate cancers. It's possible to get a hold of the book here. Tumor cells undergo apoptosis when STAT3 activation is suppressed. This review highlights the STAT3 activation and inhibition which can be used for further studies.
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Affiliation(s)
- Sowmiya Arun
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, 643001, Tamil Nadu, India
| | - Praveen Kumar Patel
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, 643001, Tamil Nadu, India
| | - Kaviarasan Lakshmanan
- Department of Pharmaceutical Chemistry, School of Pharmacy, Satyabhama Institute of Science and Technology, Chennai, India
| | - Kalirajan Rajangopal
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, 643001, Tamil Nadu, India
| | - Gomathi Swaminathan
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, 643001, Tamil Nadu, India
| | - Gowramma Byran
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, 643001, Tamil Nadu, India
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Wiedner HJ, Blue RE, Sadovsky M, Mills CA, Wehrens XH, Herring LE, Giudice J. RBFOX2 regulated EYA3 isoforms partner with SIX4 or ZBTB1 to control transcription during myogenesis. iScience 2023; 26:108258. [PMID: 38026174 PMCID: PMC10665822 DOI: 10.1016/j.isci.2023.108258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 08/14/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Alternative splicing is a prevalent gene-regulatory mechanism, with over 95% of multi-exon human genes estimated to be alternatively spliced. Here, we describe a tissue-specific, developmentally regulated, highly conserved, and disease-associated alternative splicing event in exon 7 of the eyes absent homolog 3 (Eya3) gene. We discovered that EYA3 expression is vital to the proliferation and differentiation of myoblasts. Genome-wide transcriptomic analysis and mass spectrometry-based proteomic studies identified SIX homeobox 4 (SIX4) and zinc finger and BTB-domain containing 1 (ZBTB1), as major transcription factors that interact with EYA3 to dictate gene expression. EYA3 isoforms differentially regulate transcription, indicating that splicing aids in temporal control of gene expression during muscle cell differentiation. Finally, we identified RNA-binding fox-1 homolog 2 (RBFOX2) as the main regulator of EYA3 splicing. Together, our findings illustrate the interplay between alternative splicing and transcription during myogenesis.
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Affiliation(s)
- Hannah J. Wiedner
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - R. Eric Blue
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matheus Sadovsky
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C. Allie Mills
- UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Xander H.T. Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Laura E. Herring
- UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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6
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Shamir I, Tsarfaty I, Paret G, Nevo-Caspi Y. Differential silencing of STAT3 isoforms leads to changes in STAT3 activation. Oncotarget 2023; 14:366-376. [PMID: 37097001 DOI: 10.18632/oncotarget.28412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor involved in multiple fundamental biological processes and a key player in cancer development and progression. STAT3 is activated upon tyrosine phosphorylation and is constitutively active in various malignancies; therefore, the expression of pSTAT3 has been recognized as a predictor of poor survival. STAT3 encodes two alternatively-spliced STAT3 isoforms: the full-length STAT3α isoform and the truncated STAT3β isoform. These isoforms have been suggested as the reason for the occasionally observed opposing roles of STAT3 in cancer: an oncogene, on one hand, and a tumor suppressor on the other. To investigate their roles in aggressive breast cancer, we separately silenced each isoform and found that they affect each other's activation, impacting cell viability, cytokine expression, and migration. Silencing specific isoforms can lead to a more favorable balance of activated STAT3 proteins in the cell. Distinguishing between the two isoforms and their active forms is crucial for STAT3-related cancer diagnosis and therapy.
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Affiliation(s)
- Inbal Shamir
- Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center, Ramat-Gan, Israel
| | - Ilan Tsarfaty
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gidi Paret
- Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center, Ramat-Gan, Israel
| | - Yael Nevo-Caspi
- Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center, Ramat-Gan, Israel
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Wang J, Sun Q, Wu J, Tian W, Wang H, Liu H. Identification of four STAT3 isoforms and functional investigation of IL-6/JAK2/STAT3 pathway in blunt snout bream (Megalobrama amblycephala). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 135:104484. [PMID: 35764161 DOI: 10.1016/j.dci.2022.104484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/17/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is a major regulator of immune response and chronic inflammatory, which can be activated by interleukin-6 (IL-6). In mammals, STAT3 has multiple isoforms, and its function has been well studied. In teleost, a single stat3 has been cloned and identified in several species, but studies on its function are limited. In the present study, four stat3 isoforms including mastat3α1, mastat3α2, mastat3β1 and mastat3β2 were identified from blunt snout bream (Megalobrama amblycephala). The results of quantitative PCR (qPCR) showed that four mastat3 transcripts were ubiquitously expressed in all 10 tissues examined. After Aeromonas hydrophila challenge, the expression patterns of mastat3a1, mastat3a2 and mastat3β2 were similar, but significantly different from that of mastat3β1. In addition, western blot showed that rmaIL-6+rmasIL-6R (IL-6 trans-signaling) significantly up-regulated phosphorylation levels of the four maSTAT3 isoforms and mRNA levels of the il-10, il-11, tnf-a, socs3a and socs3b genes, while rmaIL-6 (IL-6 classical signaling) only significantly up-regulated phosphorylation levels of the two maSTAT3α isoforms and mRNA levels of the il-10, socs3a and socs3b genes. Meanwhile, overexpression or inhibition of JAK2 could significantly change the STAT3 phosphorylation. Finally, JAK2 and STAT3 inhibitors could significantly inhibit the up-regulation of il-10, il-11, tnf-a, socs3a and socs3b induced by rmaIL-6+rmasIL-6R or rmaIL-6. To sum up, this study reveals the functional distinctions and overlaps among the four maSTAT3 isoforms in blunt snout bream and reveals the differential regulation of IL-6 classical signaling and trans-signaling on downstream immune genes via the JAK2/STAT3 pathway, enriching our knowledge of fish's defense mechanisms against pathogens.
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Affiliation(s)
- Jixiu Wang
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Qianhui Sun
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Jiaqi Wu
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Wanping Tian
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Huanling Wang
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Hong Liu
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affair/Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China.
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Abousaad S, Ahmed F, Abouzeid A, Ongeri EM. Meprin β expression modulates the interleukin-6 mediated JAK2-STAT3 signaling pathway in ischemia/reperfusion-induced kidney injury. Physiol Rep 2022; 10:e15468. [PMID: 36117389 PMCID: PMC9483619 DOI: 10.14814/phy2.15468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023] Open
Abstract
Meprin metalloproteinases have been implicated in the pathophysiology of ischemia/reperfusion (IR)-induced kidney injury. Previous in vitro data showed that meprin β proteolytically processes interleukin-6 (IL-6) resulting in its inactivation. Recently, meprin-β was also shown to cleave the IL-6 receptor. The goal of this study was to determine how meprin β expression impacts IL-6 and downstream modulators of the JAK2-STAT3-mediated signaling pathway in IR-induced kidney injury. IR was induced in 12-week-old male wild-type (WT) and meprin β knockout (βKO) mice and kidneys obtained at 24 h post-IR. Real-time PCR, western blot, and immunostaining/microscopy approaches were used to quantify mRNA and protein levels respectively, and immunofluorescence counterstaining with proximal tubule (PT) markers to determine protein localization. The mRNA levels for IL-6, CASP3 and BCL-2 increased significantly in both genotypes. Interestingly, western blot data showed increases in protein levels for IL-6, CASP3, and BCL-2 in the βKO but not in WT kidneys. However, immunohistochemical data showed increases in IL-6, CASP3, and BCL-2 proteins in select kidney tubules in both genotypes, shown to be PTs by immunofluorescence counterstaining. IR-induced increases in p-STAT-3 and p-JAK-2 in βKO at a global level but immunoflourescence counterstaining demonstrated p-JAK2 and p-STAT3 increases in select PT for both genotypes. BCL-2 increased only in the renal corpuscle of WT kidneys, suggesting a role for meprins expressed in leukocytes. Immunohistochemical analysis confirmed higher levels of leukocyte infiltration in WT kidneys when compared to βKO kidneys. The present data demonstrate that meprin β modulates IR-induced kidney injury in part via IL-6/JAK2/STAT3-mediated signaling.
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Affiliation(s)
- Shaymaa Abousaad
- Department of KinesiologyCollege of Health and Human Sciences, North Carolina A&T State UniversityGreensboroNorth CarolinaUSA
| | - Faihaa Ahmed
- Department of KinesiologyCollege of Health and Human Sciences, North Carolina A&T State UniversityGreensboroNorth CarolinaUSA
| | - Ayman Abouzeid
- Department of KinesiologyCollege of Health and Human Sciences, North Carolina A&T State UniversityGreensboroNorth CarolinaUSA
| | - Elimelda Moige Ongeri
- Department of KinesiologyCollege of Health and Human Sciences, North Carolina A&T State UniversityGreensboroNorth CarolinaUSA
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Carretero-González A, Hergueta-Redondo M, Sánchez-Redondo S, Ximénez-Embún P, Manso Sánchez L, Gil EC, Castellano D, de Velasco G, Peinado H. Characterization of plasma circulating small extracellular vesicles in patients with metastatic solid tumors and newly diagnosed brain metastasis. Oncoimmunology 2022; 11:2067944. [PMID: 35481283 PMCID: PMC9037466 DOI: 10.1080/2162402x.2022.2067944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nearly 40% of the advanced cancer patients will present brain metastases during the course of their disease, with a 2-year life expectancy of less than 10%. Immune system impairment, including the modulation of both STAT3 and PD-L1, is one of the hallmarks of brain metastases. Liquid biopsy could offer several advantages in brain metastases management, such as the possibility of noninvasive dynamic monitoring. Extracellular vesicles (EVs) have been recently proposed as novel biomarkers especially useful in liquid biopsy due to their secretion in biofluids and their role in cell communication during tumor progression. The main aim of this work was to characterize the size and protein cargo of plasma circulating EVs in patients with solid tumors and their correlation with newly diagnosed brain metastases, in addition to their association with other relevant clinical variables. We analyzed circulating EVs in the plasma of 123 patients: 42 patients with brain metastases, 50 without brain metastases and 31 healthy controls. Patients with newly diagnosed brain metastases had a lower number of circulating EVs in the plasma and a higher protein concentration in small EVs (sEVs) compared to patients without brain metastases and healthy controls. Interestingly, melanoma patients with brain metastases presented decreased STAT3 activation and increased PD-L1 levels in circulating sEVs compared to patients without central nervous system metastases. Decreased STAT3 activation and increased PD-L1 in plasma circulating sEVs identify melanoma patients with brain metastasis.
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Affiliation(s)
- Alberto Carretero-González
- Medical Oncology Department, University Hospital 12 de Octubre, Madrid, Spain
- Microenvironment and Metastasis Laboratory, Molecular Oncology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Marta Hergueta-Redondo
- Microenvironment and Metastasis Laboratory, Molecular Oncology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Sara Sánchez-Redondo
- Microenvironment and Metastasis Laboratory, Molecular Oncology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Pilar Ximénez-Embún
- Proteomics Unit Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Luis Manso Sánchez
- Medical Oncology Department, University Hospital 12 de Octubre, Madrid, Spain
| | - Eva Ciruelos Gil
- Medical Oncology Department, University Hospital 12 de Octubre, Madrid, Spain
| | - Daniel Castellano
- Medical Oncology Department, University Hospital 12 de Octubre, Madrid, Spain
| | | | - Héctor Peinado
- Microenvironment and Metastasis Laboratory, Molecular Oncology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain
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10
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Liu H, Du T, Li C, Yang G. STAT3 phosphorylation in central leptin resistance. Nutr Metab (Lond) 2021; 18:39. [PMID: 33849593 PMCID: PMC8045279 DOI: 10.1186/s12986-021-00569-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/03/2021] [Indexed: 12/20/2022] Open
Abstract
Mechanism exploitation of energy homeostasis is urgently required because of the worldwide prevailing of obesity-related metabolic disorders in human being. Although it is well known that leptin plays a central role in regulating energy balance by suppressing food intake and promoting energy expenditure, the existence of leptin resistance in majority of obese individuals hampers the utilization of leptin therapy against these disorders. However, the mechanism of leptin resistance is largely unknown in spite of the globally enormous endeavors. Current theories to interpret leptin resistance include the impairment of leptin transport, attenuation of leptin signaling, chronic inflammation, ER tress, deficiency of autophagy, as well as leptin itself. Leptin-activated leptin receptor (LepRb) signals in hypothalamus via several pathways, in which JAK2-STAT3 pathway, the most extensively investigated one, is considered to mediate the major action of leptin in energy regulation. Upon leptin stimulation the phosphorylation of STAT3 is one of the key events in JAK2-STAT3 pathway, followed by the dimerization and nuclear translocation of this molecule. Phosphorylated STAT3 (p-STAT3), as a transcription factor, binds to and regulates its target gene such as POMC gene, playing the physiological function of leptin. Regarding POMC gene in hypothalamus however little is known about the detail of its interaction with STAT3. Moreover the status of p-STAT3 and its significance in hypothalamus of DIO mice needs to be well elucidated. This review comprehends literatures on leptin and leptin resistance and especially discusses what STAT3 phosphorylation would contribute to central leptin resistance.
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Affiliation(s)
- Huimin Liu
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Tianxin Du
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Chen Li
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Guoqing Yang
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China.
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11
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Zheng ZY, Yang PL, Luo W, Yu SX, Xu HY, Huang Y, Li RY, Chen Y, Xu XE, Liao LD, Wang SH, Huang HC, Li EM, Xu LY. STAT3β Enhances Sensitivity to Concurrent Chemoradiotherapy by Inducing Cellular Necroptosis in Esophageal Squamous Cell Carcinoma. Cancers (Basel) 2021; 13:cancers13040901. [PMID: 33670049 PMCID: PMC7926856 DOI: 10.3390/cancers13040901] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 02/05/2023] Open
Abstract
Concurrent chemoradiotherapy (CCRT), especially platinum plus radiotherapy, is considered to be one of the most promising treatment modalities for patients with advanced esophageal cancer. STAT3β regulates specific target genes and inhibits the process of tumorigenesis and development. It is also a good prognostic marker and a potential marker for response to adjuvant chemoradiotherapy (ACRT). We aimed to investigate the relationship between STAT3β and CCRT. We examined the expression of STAT3α and STAT3β in pretreatment tumor biopsies of 105 ESCC patients who received CCRT by immunohistochemistry. The data showed that ESCC patients who demonstrate both high STAT3α expression and high STAT3β expression in the cytoplasm have a significantly better survival rate, and STAT3β expression is an independent protective factor (HR = 0.424, p = 0.003). Meanwhile, ESCC patients with high STAT3β expression demonstrated a complete response to CCRT in 65 patients who received platinum plus radiation therapy (p = 0.014). In ESCC cells, high STAT3β expression significantly inhibits the ability of colony formation and cell proliferation, suggesting that STAT3β enhances sensitivity to CCRT (platinum plus radiation therapy). Mechanistically, through RNA-seq analysis, we found that the TNF signaling pathway and necrotic cell death pathway were significantly upregulated in highly expressed STAT3β cells after CCRT treatment. Overall, our study highlights that STAT3β could potentially be used to predict the response to platinum plus radiation therapy, which may provide an important insight into the treatment of ESCC.
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Affiliation(s)
- Zhen-Yuan Zheng
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
| | - Ping-Lian Yang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Wei Luo
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Shuai-Xia Yu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Hong-Yao Xu
- Departments of Radiation Oncology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China; (H.-Y.X.); (H.-C.H.)
| | - Ying Huang
- Departments of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China; (Y.H.); (S.-H.W.)
| | - Rong-Yao Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
| | - Yang Chen
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Xiu-E Xu
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Lian-Di Liao
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
| | - Shao-Hong Wang
- Departments of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China; (Y.H.); (S.-H.W.)
| | - He-Cheng Huang
- Departments of Radiation Oncology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China; (H.-Y.X.); (H.-C.H.)
| | - En-Min Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
- Correspondence: (E.-M.L.); (L.-Y.X.)
| | - Li-Yan Xu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, China; (Z.-Y.Z.); (P.-L.Y.); (W.L.); (S.-X.Y.); (R.-Y.L.); (Y.C.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China; (X.-E.X.); (L.-D.L.)
- Correspondence: (E.-M.L.); (L.-Y.X.)
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Mirzaei S, Gholami MH, Mahabady MK, Nabavi N, Zabolian A, Banihashemi SM, Haddadi A, Entezari M, Hushmandi K, Makvandi P, Samarghandian S, Zarrabi A, Ashrafizadeh M, Khan H. Pre-clinical investigation of STAT3 pathway in bladder cancer: Paving the way for clinical translation. Biomed Pharmacother 2020; 133:111077. [PMID: 33378975 DOI: 10.1016/j.biopha.2020.111077] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 02/07/2023] Open
Abstract
Effective cancer therapy requires identification of signaling networks and investigating their potential role in proliferation and invasion of cancer cells. Among molecular pathways, signal transducer and activator of transcription 3 (STAT3) has been of importance due to its involvement in promoting proliferation, and invasion of cancer cells, and mediating chemoresistance. In the present review, our aim is to reveal role of STAT3 pathway in bladder cancer (BC), as one of the leading causes of death worldwide. In respect to its tumor-promoting role, STAT3 is able to enhance the growth of BC cells via inhibiting apoptosis and cell cycle arrest. STAT3 also contributes to metastasis of BC cells via upregulating of MMP-2 and MMP-9 as well as genes in the EMT pathway. BC cells obtain chemoresistance via STAT3 overexpression and its inhibition paves the way for increasing efficacy of chemotherapy. Different molecular pathways such as KMT1A, EZH2, DAB2IP and non-coding RNAs including microRNAs and long non-coding RNAs can function as upstream mediators of STAT3 that are discussed in this review article.
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Affiliation(s)
- Sepideh Mirzaei
- Department of Biology, Faculty of Science, Islamic Azad University, Science and Research Branch, Tehran, Iran
| | | | - Mahmood Khaksary Mahabady
- Anatomical Sciences Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Noushin Nabavi
- Research Services, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Amirhossein Zabolian
- Young Researchers and Elite Club, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | | | - Amirabbas Haddadi
- Young Researchers and Elite Club, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Maliheh Entezari
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Kiavash Hushmandi
- Department of Food Hygiene and Quality Control, Division of Epidemiology & Zoonoses, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Pooyan Makvandi
- IstitutoItaliano di Tecnologia, Centre for Micro-BioRobotics, viale Rinaldo Piaggio 34, 56025, Pontedera, Pisa, Italy
| | - Saeed Samarghandian
- Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran
| | - Ali Zarrabi
- Sabanci University Nanotechnology Research and Application Center (SUNUM), Tuzla, 34956, Istanbul, Turkey.
| | - Milad Ashrafizadeh
- Sabanci University Nanotechnology Research and Application Center (SUNUM), Tuzla, 34956, Istanbul, Turkey; Faculty of Engineering and Natural Sciences, Sabanci University, OrtaMahalle, ÜniversiteCaddesi No. 27, Orhanlı, Tuzla, 34956, Istanbul, Turkey.
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan.
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Yang PL, Liu LX, Li EM, Xu LY. STAT3, the Challenge for Chemotherapeutic and Radiotherapeutic Efficacy. Cancers (Basel) 2020; 12:cancers12092459. [PMID: 32872659 PMCID: PMC7564975 DOI: 10.3390/cancers12092459] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 02/05/2023] Open
Abstract
Chemoradiotherapy is one of the most effective and extensively used strategies for cancer treatment. Signal transducer and activator of transcription 3 (STAT3) regulates vital biological processes, such as cell proliferation and cell growth. It is constitutively activated in various cancers and limits the application of chemoradiotherapy. Accumulating evidence suggests that STAT3 regulates resistance to chemotherapy and radiotherapy and thereby impairs therapeutic efficacy by mediating its feedback loop and several target genes. The alternative splicing product STAT3β is often identified as a dominant-negative regulator, but it enhances sensitivity to chemotherapy and offers a new and challenging approach to reverse therapeutic resistance. We focus here on exploring the role of STAT3 in resistance to receptor tyrosine kinase (RTK) inhibitors and radiotherapy, outlining the potential of targeting STAT3 to overcome chemo(radio)resistance for improving clinical outcomes, and evaluating the importance of STAT3β as a potential therapeutic approach to overcomes chemo(radio)resistance. In this review, we discuss some new insights into the effect of STAT3 and its subtype STAT3β on chemoradiotherapy sensitivity, and we explore how these insights influence clinical treatment and drug development for cancer.
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Affiliation(s)
- Ping-Lian Yang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, China; (P.-L.Y.); (L.-X.L.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - Lu-Xin Liu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, China; (P.-L.Y.); (L.-X.L.)
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - En-Min Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, China; (P.-L.Y.); (L.-X.L.)
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, China
- Correspondence: (E.-M.L.); (L.-Y.X.); Tel.: +86-754-88900460 (L.-Y.X.); Fax: +86-754-88900847 (L.-Y.X.)
| | - Li-Yan Xu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, China; (P.-L.Y.); (L.-X.L.)
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, Guangdong, China
- Correspondence: (E.-M.L.); (L.-Y.X.); Tel.: +86-754-88900460 (L.-Y.X.); Fax: +86-754-88900847 (L.-Y.X.)
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14
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STAT3β is a tumor suppressor in acute myeloid leukemia. Blood Adv 2020; 3:1989-2002. [PMID: 31270081 DOI: 10.1182/bloodadvances.2018026385] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 05/04/2019] [Indexed: 12/17/2022] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) exists in 2 alternatively spliced isoforms, STAT3α and STAT3β. Although truncated STAT3β was originally postulated to act as a dominant-negative form of STAT3α, it has been shown to have various STAT3α-independent regulatory functions. Recently, STAT3β gained attention as a powerful antitumorigenic molecule in cancer. Deregulated STAT3 signaling is often found in acute myeloid leukemia (AML); however, the role of STAT3β in AML remains elusive. Therefore, we analyzed the STAT3β/α messenger RNA (mRNA) expression ratio in AML patients, where we observed that a higher STAT3β/α mRNA ratio correlated with a favorable prognosis and increased overall survival. To gain better understanding of the function of STAT3β in AML, we engineered a transgenic mouse allowing for balanced Stat3β expression. Transgenic Stat3β expression resulted in decelerated disease progression and extended survival in PTEN- and MLL-AF9-dependent AML mouse models. Our findings further suggest that the antitumorigenic function of STAT3β depends on the tumor-intrinsic regulation of a small set of significantly up- and downregulated genes, identified via RNA sequencing. In conclusion, we demonstrate that STAT3β plays an essential tumor-suppressive role in AML.
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Mechanistic Study of Triazole Based Aminodiol Derivatives in Leukemic Cells-Crosstalk between Mitochondrial Stress-Involved Apoptosis and Autophagy. Int J Mol Sci 2020; 21:ijms21072470. [PMID: 32252439 PMCID: PMC7177546 DOI: 10.3390/ijms21072470] [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: 02/05/2020] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 11/17/2022] Open
Abstract
Various derivatives that mimic ceramide structures by introducing a triazole to connect the aminodiol moiety and long alkyl chain have been synthesized and screened for their anti-leukemia activity. SPS8 stood out among the derivatives, showing cytotoxic selectivity between leukemic cell lines and human peripheral blood mononuclear cells (about ten times). DAPI nuclear staining and H&E staining revealed DNA fragmentation under the action of SPS8. SPS8 induced an increase in intracellular Ca2+ levels and mitochondrial stress in HL-60 cells identified by the loss of mitochondrial membrane potential, transmission electron microscopy (TEM) examination, and altered expressions of Bcl-2 family proteins. SPS8 also induced autophagy through the detection of Atg5, beclin-1, and LC3 II protein expression, as well as TEM examination. Chloroquine, an autophagy inhibitor, promoted SPS8-induced apoptosis, suggesting the cytoprotective role of autophagy in hindering SPS8 from apoptosis. Furthermore, SPS8 was shown to alter the expressions of a variety of genes using a microarray analysis and volcano plot filtering. A further cellular signaling pathways analysis suggested that SPS8 induced several cellular processes in HL-60, including the sterol biosynthesis process and cholesterol biosynthesis process, and inhibited some cellular pathways, in which STAT3 was the most critical nuclear factor. Further identification revealed that SPS8 inhibited the phosphorylation of STAT3, representing the loss of cytoprotective activity. In conclusion, the data suggest that SPS8 induces both apoptosis and autophagy in leukemic cells, in which autophagy plays a cytoprotective role in impeding apoptosis. Moreover, the inhibition of STAT3 phosphorylation may support SPS8-induced anti-leukemic activity.
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Belluti S, Rigillo G, Imbriano C. Transcription Factors in Cancer: When Alternative Splicing Determines Opposite Cell Fates. Cells 2020; 9:E760. [PMID: 32244895 PMCID: PMC7140685 DOI: 10.3390/cells9030760] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/05/2020] [Accepted: 03/17/2020] [Indexed: 02/08/2023] Open
Abstract
Alternative splicing (AS) is a finely regulated mechanism for transcriptome and proteome diversification in eukaryotic cells. Correct balance between AS isoforms takes part in molecular mechanisms that properly define spatiotemporal and tissue specific transcriptional programs in physiological conditions. However, several diseases are associated to or even caused by AS alterations. In particular, multiple AS changes occur in cancer cells and sustain the oncogenic transcriptional program. Transcription factors (TFs) represent a key class of proteins that control gene expression by direct binding to DNA regulatory elements. AS events can generate cancer-associated TF isoforms with altered activity, leading to sustained proliferative signaling, differentiation block and apoptosis resistance, all well-known hallmarks of cancer. In this review, we focus on how AS can produce TFs isoforms with opposite transcriptional activities or antagonistic functions that severely impact on cancer biology. This summary points the attention to the relevance of the analysis of TFs splice variants in cancer, which can allow patients stratification despite the presence of interindividual genetic heterogeneity. Recurrent TFs variants that give advantage to specific cancer types not only open the opportunity to use AS transcripts as clinical biomarkers but also guide the development of new anti-cancer strategies in personalized medicine.
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Affiliation(s)
| | | | - Carol Imbriano
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 213/D, 41125 Modena, Italy; (S.B.); (G.R.)
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Binder S, Zipfel I, Friedrich M, Riedel D, Ende S, Kämpf C, Wiedemann K, Buschmann T, Puppel SH, Reiche K, Stadler PF, Horn F. Master and servant: LINC00152 - a STAT3-induced long noncoding RNA regulates STAT3 in a positive feedback in human multiple myeloma. BMC Med Genomics 2020; 13:22. [PMID: 32041604 PMCID: PMC7011539 DOI: 10.1186/s12920-020-0692-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 01/31/2020] [Indexed: 12/16/2022] Open
Abstract
Background The survival of INA-6 human multiple myeloma cells is strictly dependent upon the Interleukin-6-activated transcription factor STAT3. Although transcriptional analyses have revealed many genes regulated by STAT3, to date no protein-coding STAT3 target gene is known to mediate survival in INA-6 cells. Therefore, the aim here was to identify and analyze non-protein-coding STAT3 target genes. In addition to the oncogenic microRNA-21, we previously described five long noncoding RNAs (lncRNAs) induced by STAT3, named STAiRs. Here, we focus on STAT3-induced RNA 18 (STAiR18), an mRNA-like, long ncRNA that is duplicated in the human lineage. One STAiR18 locus is annotated as the already well described LINC00152/CYTOR, however, the other harbors the MIR4435-2HG gene and is, up to now, barely described. Methods CAPTURE-RNA-sequencing was used to analyze STAiR18 transcript architecture. To identify the STAiR18 and STAT3 phenotype, siRNA-based knockdowns were performed and microarrays were applied to identify their target genes. RNA-binding partners of STAiR18 were determined by Chromatin-Isolation-by-RNA-Purification (ChIRP) and subsequent sequencing. STAT3 expression in dependence of STAiR18 was investigated by immunoblots, chromatin- and RNA-immunoprecipitations. Results As identified by CAPTURE-RNA sequencing, a complex splice pattern originates from both STAiR18 loci, generating different transcripts. Knockdown of the most abundant STAiR18 isoforms dramatically decreased INA-6 cell vitality, suggesting a functional role in myeloma cells. Additionally, STAiR18 and STAT3 knockdowns yielded overlapping changes of transcription patterns in INA-6 cells, suggesting a close functional interplay between the two factors. Moreover, Chromatin isolation by RNA purification (ChIRP), followed by genome-wide RNA sequencing showed that STAiR18 associates specifically with the STAT3 primary transcript. Furthermore, the knockdown of STAiR18 reduced STAT3 levels on both the RNA and protein levels, suggesting a positive feedback between both molecules. Furthermore, STAiR18 knockdown changes the histone methylation status of the STAT3 locus, which explains the positive feedback and indicates that STAiR18 is an epigenetic modulator. Conclusion Hence, STAiR18 is an important regulator of myeloma cell survival and is strongly associated with the oncogenic function of STAT3. The close functional interplay between STAT3 and STAiR18 suggests a novel principle of regulatory interactions between long ncRNAs and signaling pathways.
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Affiliation(s)
- Stefanie Binder
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany. .,Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany.
| | - Ivonne Zipfel
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Maik Friedrich
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Diana Riedel
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Stefanie Ende
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Christoph Kämpf
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Karolin Wiedemann
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Tilo Buschmann
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Sven-Holger Puppel
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Kristin Reiche
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany.,German Centre for Integrative Biodiversity Research - iDiv, Halle-Jena-Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Department of Theoretical Chemistry, University of Vienna, Wien, Austria.,Center for RNA in Technology and Health, University of Copenhagen, København, Denmark.,Santa Fe Institute, Santa Fe, USA
| | - Friedemann Horn
- Institute of Clinical Immunology, Faculty of Medicine, University of Leipzig, Leipzig, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Department of Diagnostics, Leipzig, Germany
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Verhoeven Y, Tilborghs S, Jacobs J, De Waele J, Quatannens D, Deben C, Prenen H, Pauwels P, Trinh XB, Wouters A, Smits EL, Lardon F, van Dam PA. The potential and controversy of targeting STAT family members in cancer. Semin Cancer Biol 2020; 60:41-56. [DOI: 10.1016/j.semcancer.2019.10.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/30/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022]
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Hu YS, Han X, Liu XH. STAT3: A Potential Drug Target for Tumor and Inflammation. Curr Top Med Chem 2019; 19:1305-1317. [PMID: 31218960 DOI: 10.2174/1568026619666190620145052] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/25/2019] [Accepted: 05/09/2019] [Indexed: 12/12/2022]
Abstract
STAT (Signal Transducers and Activators of Transcription) is a cellular signal transcription factor involved in the regulation of many cellular activities, such as cell differentiation, proliferation, angiogenesis in normal cells. During the study of the STAT family, STAT3 was found to be involved in many diseases, such as high expression and sustained activation of STAT3 in tumor cells, promoting tumor growth and proliferation. In the study of inflammation, it was found that it plays an important role in the anti-inflammatory and repairing of damage tissues. Because of the important role of STAT3, a large number of studies have been obtained. At the same time, after more than 20 years of development, STAT3 has also been used as a target for drug therapy. And the discovery of small molecule inhibitors also promoted the study of STAT3. Since STAT3 has been extensively studied in inflammation and tumor regulation, this review presents the current state of research on STAT3.
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Affiliation(s)
- Yang Sheng Hu
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, 230032, China
| | - Xu Han
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, 230032, China
| | - Xin Hua Liu
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, 230032, China
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STAT3 isoforms: Alternative fates in cancer? Cytokine 2019; 118:27-34. [DOI: 10.1016/j.cyto.2018.07.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 02/04/2023]
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Wang X, Guo J, Che X, Jia R. PCBP1 inhibits the expression of oncogenic STAT3 isoform by targeting alternative splicing of STAT3 exon 23. Int J Biol Sci 2019; 15:1177-1186. [PMID: 31223278 PMCID: PMC6567812 DOI: 10.7150/ijbs.33103] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 03/28/2019] [Indexed: 01/27/2023] Open
Abstract
STAT3 plays very important roles in the initiation and development of tumors. Despite of extensive studies in repressing its activation and function via multiple ways, so far, there are few effective therapeutic methods to inhibit STAT3 in the clinic. STAT3 has two isoforms generated by alternative splicing of exon 23. STAT3α is the longer isoform and encodes the full-length oncogenic STAT3α protein. STAT3β is shorter and encodes the truncated and tumor-suppressive STAT3β protein. It remains unknown how the alternative splicing of STAT3 exon 23 is regulated. Here, we discovered that there is an exonic splicing suppressor (ESS) in exon 23. Importantly, splicing factor PCBP1 binds to this ESS. Overexpression of PCBP1 significantly reduced the proportion of STAT3α /STAT3β isoforms and the expression of STAT3α protein. Moreover, increased PCBP1 inhibited the growth of oral squamous cell carcinoma and breast cancer cells, and the expression of STAT3 target genes. Our results demonstrated that PCBP1 is the key splicing factor that promotes the switch from oncogenic isoform STAT3α to tumor-suppressive isoform STAT3β. Our results pave the way for finding new anti-STAT3 methods for cancer treatment.
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Affiliation(s)
- Xiaole Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Jihua Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.,Department of Endodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Xiaoxuan Che
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
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22
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Zhang HX, Yang PL, Li EM, Xu LY. STAT3beta, a distinct isoform from STAT3. Int J Biochem Cell Biol 2019; 110:130-139. [PMID: 30822557 DOI: 10.1016/j.biocel.2019.02.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 02/08/2019] [Accepted: 02/20/2019] [Indexed: 02/05/2023]
Abstract
STAT3β is an isoform of STAT3 (signal transducer and activator of transcription 3) that differs from the STAT3α isoform by the replacement of the C-terminal 55 amino acid residues with 7 specific residues. The constitutive activation of STAT3α plays a pivotal role in the activation of oncogenic pathways, such as cell proliferation, maturation and survival, while STAT3β is often referred to as a dominant-negative regulator of cancer. STAT3β reveals a "spongy cushion" effect through its cooperation with STAT3α or forms a ternary complex with other co-activators. Especially in tumour cells, relatively high levels of STAT3β lead to some favourable changes. However, there are still many mechanisms that have not been clearly explained in contrast to STAT3α, such as STAT3β nuclear retention, more stable heterodimers and the prolonged Y705 phosphorylation. In addition to its transcriptional activities, STAT3β may also function in the cytosol with respect to the mitochondria, cytoskeleton rearrangements and metastasis of cancer cells. In this review, we summarize the mechanisms that underlie the unique roles of STAT3β combined with total STAT3 to enlighten and draw the attention of researchers studying STAT3 and discuss some interesting questions that warrant answers.
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Affiliation(s)
- Hui-Xiang Zhang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncological Pathology, Shantou University Medical College, Shantou, Guangdong, PR China
| | - Ping-Lian Yang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncological Pathology, Shantou University Medical College, Shantou, Guangdong, PR China
| | - En-Min Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China.
| | - Li-Yan Xu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncological Pathology, Shantou University Medical College, Shantou, Guangdong, PR China.
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Arora L, Kumar AP, Arfuso F, Chng WJ, Sethi G. The Role of Signal Transducer and Activator of Transcription 3 (STAT3) and Its Targeted Inhibition in Hematological Malignancies. Cancers (Basel) 2018; 10:cancers10090327. [PMID: 30217007 PMCID: PMC6162647 DOI: 10.3390/cancers10090327] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/10/2018] [Accepted: 09/11/2018] [Indexed: 12/22/2022] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3), a member of the STAT protein family, can be phosphorylated by receptor-associated Janus kinases (JAKs) in response to stimulation by cytokines and growth factors. It forms homo- or heterodimers that can translocate to the cell nucleus where they act as transcription activators. Constitutive activation of STAT3 has been found to be associated with initiation and progression of various cancers. It can exert proliferative as well as anti-apoptotic effects. This review focuses on the role of STAT3 in pathogenesis i.e., proliferation, differentiation, migration, and apoptosis of hematological malignancies viz. leukemia, lymphoma and myeloma, and briefly highlights the potential therapeutic approaches developed against STAT3 activation pathway.
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Affiliation(s)
- Loukik Arora
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore.
| | - Alan Prem Kumar
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore.
- Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, #11-01M, Singapore 117599, Singapore.
- Medical Science Cluster, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore.
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia.
- National University Cancer Institute, National University Health System, Singapore 119074, Singapore.
| | - Frank Arfuso
- Stem Cell and Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia.
| | - Wee Joo Chng
- Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, #11-01M, Singapore 117599, Singapore.
- Department of Hematology-Oncology, National University Cancer Institute, National University Health System, Singapore 119074, Singapore.
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore.
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6009, Australia.
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Wang X, Du L, Wei H, Zhang A, Yang K, Zhou H. Identification of two Stat3 variants lacking a transactivation domain in grass carp: New insights into alternative splicing in the modification of teleost Stat3 signaling. FISH & SHELLFISH IMMUNOLOGY 2018; 77:13-21. [PMID: 29555584 DOI: 10.1016/j.fsi.2018.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT family in response to cytokines and growth factors. In mammals, alternative splicing of STAT3 generates STAT3α and STAT3β, which have distinct and overlapping functions. In the previous study, we have identified two spliceforms of Stat3α (Stat3α1 and Stat3α2) possessing all functional domains of Stat3 in grass carp (Ctenopharyngodon idella). In the present study, two Stat3β variants (Stat3β1 and Stat3β2) without C-terminal transactivation domain were isolated from this species, and their transcripts were ubiquitously expressed in all examined tissues with the highest levels in liver. Further studies showed that Stat3β1/2 had the ability to translocate into the nucleus upon activation, indicating their roles in transcriptional regulation. In support of this notion, grass carp Stat3β1 and Stat3β2 displayed the abilities to inhibit Interleukin-10 (Il-10) signaling and competitively impaired the transcriptional activities of Stat3α1/2. In particular, similar to their mammalian counterparts, grass carp Stat3β1 and Stat3β2 could enhance Stat3α1/2 phosphorylation upon cytokine stimulation. Interestingly, stat3β1 and stat3β2 transcripts were also found in zebrafish (Danio rerio) and goldfish (Carassius auratus), and each variant in these teleosts is generated through similar alternative splicing events, including exon skipping and intron retention. This highlights a conserved splicing event of stat3 gene during vertebrate evolution and indicates a potential physiological significance of generating unique Stat3 variants in fish. These results, along with the findings regarding Stat3α1/2, demonstrate the existence of Stat3 isoforms with functional diversity and redundancy in teleosts. It leads to the hypothesis that teleost-specific spliceforms of Stat3 gene may contribute to the complexity of Stat3 signaling in fishes, thereby benefiting them to adapt to evolution and environmental changes.
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Affiliation(s)
- Xinyan Wang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Linyong Du
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - He Wei
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Anying Zhang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Kun Yang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Hong Zhou
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China.
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25
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Abstract
Signal transducer and activator of transcription (STAT) 3 is a key signalling protein engaged by a multitude of growth factors and cytokines to elicit diverse biological outcomes including cellular growth, differentiation, and survival. The complete loss of STAT3 is not compatible with life and even partial loss of function mutations lead to debilitating pathologies like hyper IgE syndrome. Conversely, augmented STAT3 activity has been reported in as many as 50% of all human tumours. The dogma of STAT3 activity posits that it is a tyrosine phosphorylated transcription factor which modulates the expression of hundreds of genes. However, the regulation and biological consequences of STAT3 activation are far more complex. In addition to tyrosine phosphorylation, STAT3 is decorated with a plethora of post-translational modifications which regulate STAT3's nuclear function in addition to its non-genomic activities. In addition to these emerging complexities in the biochemical regulation of STAT3 activity, recent studies reveal that STAT3 is either oncogenic or a tumour suppressor. This review will explore these complexities.
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Affiliation(s)
- Aleks C Guanizo
- a Centre for Cancer Research , Hudson Institute of Medical Research , Clayton , VIC , Australia
- b Department of Molecular and Translational Science , Monash University , Clayton , VIC , Australia
| | - Chamira Dilanka Fernando
- a Centre for Cancer Research , Hudson Institute of Medical Research , Clayton , VIC , Australia
- b Department of Molecular and Translational Science , Monash University , Clayton , VIC , Australia
| | - Daniel J Garama
- a Centre for Cancer Research , Hudson Institute of Medical Research , Clayton , VIC , Australia
- b Department of Molecular and Translational Science , Monash University , Clayton , VIC , Australia
| | - Daniel J Gough
- a Centre for Cancer Research , Hudson Institute of Medical Research , Clayton , VIC , Australia
- b Department of Molecular and Translational Science , Monash University , Clayton , VIC , Australia
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26
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A preliminary immunohistochemical study of signal transducer and activator of transcription (STAT) proteins in primary oral malignant melanoma. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 125:164-171. [DOI: 10.1016/j.oooo.2017.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 10/14/2017] [Accepted: 10/23/2017] [Indexed: 02/03/2023]
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Goldberg L, Abutbul-Amitai M, Paret G, Nevo-Caspi Y. Alternative Splicing of STAT3 Is Affected by RNA Editing. DNA Cell Biol 2017; 36:367-376. [PMID: 28278381 DOI: 10.1089/dna.2016.3575] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A-to-I RNA editing, carried out by adenosine deaminase acting on RNA (ADAR) enzymes, is an epigenetic phenomenon of posttranscriptional modifications on pre-mRNA. RNA editing in intronic sequences may influence alternative splicing of flanking exons. We have previously shown that conditions that induce editing result in elevated expression of signal transducer and activator of transcription 3 (STAT3), preferentially the alternatively-spliced STAT3β isoform. Mechanisms regulating alternative splicing of STAT3 have not been elucidated. STAT3 undergoes A-to-I RNA editing in an intron residing in proximity to the alternatively spliced exon. We hypothesized that RNA editing plays a role in regulating alternative splicing toward STAT3β. In this study we extend our observation connecting RNA editing to the preferential induction of STAT3β expression. We study the involvement of ADAR1 in STAT3 editing and reveal the connection between editing and alternative splicing of STAT3. Deferoaxamine treatment caused the induction in STAT3 RNA editing and STAT3β expression. Silencing ADAR1 caused a decrease in STAT3 editing and expression with a preferential decrease in STAT3β. Cells transfected with a mutated minigene showed preferential splicing toward the STAT3β transcript. Editing in the STAT3 intron is performed by ADAR1 and affects STAT3 alternative splicing. These results suggest that RNA editing is one of the molecular mechanisms regulating the expression of STAT3β.
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Affiliation(s)
- Lior Goldberg
- 1 Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center , Tel Hashomer, Israel .,2 Sackler Medical School, Tel-Aviv University , Tel-Aviv, Israel
| | - Mor Abutbul-Amitai
- 1 Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center , Tel Hashomer, Israel .,2 Sackler Medical School, Tel-Aviv University , Tel-Aviv, Israel
| | - Gideon Paret
- 1 Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center , Tel Hashomer, Israel .,2 Sackler Medical School, Tel-Aviv University , Tel-Aviv, Israel
| | - Yael Nevo-Caspi
- 1 Department of Pediatric Critical Care Medicine, Safra Children's Hospital, Sheba Medical Center , Tel Hashomer, Israel
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28
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Lee H, Lee JW, Yoo KD, Yoo JY, Lee JP, Kim DK, Chin HJ, Kim YS, Yang SH. Cln 3-requiring 9 is a negative regulator of Th17 pathway-driven inflammation in anti-glomerular basement membrane glomerulonephritis. Am J Physiol Renal Physiol 2016; 311:F505-19. [DOI: 10.1152/ajprenal.00533.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/13/2016] [Indexed: 01/17/2023] Open
Abstract
T helper 17 (Th17) lymphocytes promote renal inflammation in anti-glomerular basement membrane glomerulonephritis (anti-GBM GN), and signal transducer and activator of transcription 3 (STAT3) mediates activation of Th17 lymphocytes by IL-6 and transforming growth factor-β (TGF-β). Cln 3-requiring 9 (Ctr9), a subunit of RNA polymerase-associated factor complex (PAFc), regulates the transcription of IL-6/STAT3-dependent genes. Here, we investigated the role of Ctr9 in regulating Th17-driven inflammation in anti-GBM GN. In mice, STAT3β or IL-17 knockout ameliorated anti-GBM autoantibody-induced renal injury. This phenomenon was associated with decreases in retinoic acid receptor-related orphan receptor γt (RORγt), IL-17, phosphorylated STAT3, and proinflammatory cytokines. Compared with wild-type mice, Ctr9 increased in both STAT3β−/− and IL-17−/− mice injected with anti-GBM IgG, showing a negative correlation with Th17-related transcripts. Small interfering RNA (siRNA)-mediated knockdown of Ctr9 in intrarenal lymphocytes further upregulated Th17-related transcripts, consistent with repression of Th17 differentiation by Ctr9. Interestingly, Ctr9 was also expressed in human and mouse mesangial cells and downregulated in response to anti-GBM IgG or to TGF-β plus IL-17. Ctr9 in mesangial cells was even more repressed in the presence of both anti-GBM IgG and Th17-activating cytokines. Consistent with these findings, renal biopsies obtained from patients with anti-GBM GN showed consistent downregulation of Ctr9 and upregulation of phosphorylated STAT3 and IL-17 in the glomerulus. We conclude that Ctr9 is a negative regulator of Th17 differentiation in anti-GBM GN and repressed by anti-GBM IgG and IL-17 in mesangial cells.
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Affiliation(s)
- Hajeong Lee
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jae Wook Lee
- Nephrology Clinic, National Cancer Center Hospital, Seoul, Republic of Korea
| | - Kyung Don Yoo
- Department of Medical Science, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Internal Medicine, Dongguk University Medical Center, Gyeongju, Republic of Korea
| | - Joo-Yeon Yoo
- Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jung Pyo Lee
- Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Dong Ki Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
- Kidney Research Institute, Seoul National University, Seoul, Republic of Korea; and
| | - Ho Jun Chin
- Nephrology Clinic, National Cancer Center Hospital, Seoul, Republic of Korea
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul, Republic of Korea
| | - Yon Su Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Medical Science, Seoul National University College of Medicine, Seoul, Republic of Korea
- Kidney Research Institute, Seoul National University, Seoul, Republic of Korea; and
| | - Seung Hee Yang
- Kidney Research Institute, Seoul National University, Seoul, Republic of Korea; and
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29
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Malemud CJ, Meszaros EC, Wylie MA, Dahoud W, Skomorovska-Prokvolit Y, Mesiano S. Matrix Metalloproteinase-9 Production by Immortalized Human Chondrocyte Lines. ACTA ACUST UNITED AC 2016; 7. [PMID: 27398263 PMCID: PMC4937998 DOI: 10.4172/2155-9899.1000422] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
We reported at the Keynote Forum of Immunology Summit-2015 that recombinant human (rh) TNF-α or rhIL-6 stimulated production of matrix metalloproteinase-9 (MMP-9) in the T/C28a2 and C-28/I2 human immortalized chondrocyte cell lines. Furthermore, we reported that tocilizumab (TCZ), a fully humanized monoclonal antibody which neutralizes IL-6-mediated signaling, inhibited the rhIL-6-mediated increase in the production of MMP-9. IL-6 is also a known activator of the JAK/STAT signaling pathway. In that regard, we evaluated the effect of rhIL-6 on total and phosphorylated Signal Transducer and Activator of Transcription by these chondrocyte lines which showed that whereas STAT3 was constitutively phosphorylated in T/C28a2 chondrocytes, rhIL-6 activated STAT3 in C-28/I2 chondrocytes. The finding that rhIL-6 increased the production of MMP-9 by human immortalized chondrocyte cell lines may have important implications with respect to the destruction of articular cartilage in rheumatoid arthritis and osteoarthritis. Thus, the markedly elevated level of IL-6 in rheumatoid arthritis and osteoarthritis sera and synovial fluid would be expected to generate significant MMP-9 to cause the degradation of articular cartilage extracellular matrix proteins. The finding that TCZ suppressed rhIL-6-mediated MMP-9 production suggests that TCZ, currently employed in the medical therapy of rheumatoid arthritis, could be considered as a drug for osteoarthritis.
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Affiliation(s)
- Charles J Malemud
- Department of Medicine, Division of Rheumatic Diseases, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA
| | - Evan C Meszaros
- Department of Medicine, Division of Rheumatic Diseases, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA
| | - Meredith A Wylie
- Department of Medicine, Division of Rheumatic Diseases, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA
| | - Wissam Dahoud
- Department of Reproductive Biology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA; Department of Pathology, Institute of Pathology, Case Western Reserve University, School of Medicine, University Hospitals Case Medical Center, Cleveland, Ohio 44106, USA
| | | | - Sam Mesiano
- Department of Reproductive Biology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA
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30
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Quantifying the dynamics of the oligomeric transcription factor STAT3 by pair correlation of molecular brightness. Nat Commun 2016; 7:11047. [PMID: 27009358 PMCID: PMC4820838 DOI: 10.1038/ncomms11047] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 02/16/2016] [Indexed: 12/21/2022] Open
Abstract
Oligomerization of transcription factors controls their translocation into the nucleus and DNA-binding activity. Here we present a fluorescence microscopy analysis termed pCOMB (pair correlation of molecular brightness) that tracks the mobility of different oligomeric species within live cell nuclear architecture. pCOMB amplifies the signal from the brightest species present and filters the dynamics of the extracted oligomeric population based on arrival time between two locations. We use this method to demonstrate a dependence of signal transducer and activator of transcription 3 (STAT3) mobility on oligomeric state. We find that on entering the nucleus STAT3 dimers must first bind DNA to form STAT3 tetramers, which are also DNA-bound but exhibit a different mobility signature. Examining the dimer-to-tetramer transition by a cross-pair correlation analysis (cpCOMB) reveals that chromatin accessibility modulates STAT3 tetramer formation. Thus, the pCOMB approach is suitable for mapping the impact oligomerization on transcription factor dynamics.
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31
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Zhang HF, Chen Y, Wu C, Wu ZY, Tweardy DJ, Alshareef A, Liao LD, Xue YJ, Wu JY, Chen B, Xu XE, Gopal K, Gupta N, Li EM, Xu LY, Lai R. The Opposing Function of STAT3 as an Oncoprotein and Tumor Suppressor Is Dictated by the Expression Status of STAT3β in Esophageal Squamous Cell Carcinoma. Clin Cancer Res 2016; 22:691-703. [PMID: 26405196 DOI: 10.1158/1078-0432.ccr-15-1253] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/22/2015] [Indexed: 02/05/2023]
Abstract
PURPOSE STAT3 is known to have both oncogenic and tumor suppressive effects, but the regulation of these opposing effects is elusive. We hypothesized that STAT3β, one of the two STAT3 isoforms, is the key determinant in this context. EXPERIMENTAL DESIGN The prognostic significance of STAT3β and phospho-STAT3α(Y705) (pSTAT3α(Y705)) was evaluated in 286 cases of patients with esophageal squamous cell carcinoma (ESCC). STAT3β-induced changes in the chemosensitivity to cisplatin and 5-fluorouracil were assessed both in vitro and in vivo. STAT3β-induced changes in the frequency of cancer stem cells were evaluated using Hoechst and CD44 staining. How STAT3β regulates STAT3α was determined using immunoprecipitation, confocal microscopy, DNA-binding, and chromatin immunoprecipitation-PCR. RESULTS STAT3β expression is an independent protective prognostic marker in patients with ESCC, which strongly correlated with longer overall survival (P = 0.0009) and recurrence-free survival (P = 0.0001). STAT3β significantly decreased the cancer stem cell population, and sensitized ESCC cells to cisplatin and 5-fluorouracil in tumor xenografts. Mechanistically, STAT3β markedly attenuated the transcription activity of STAT3α via inducing STAT3α:STAT3β heterodimers. However, the heterodimer formation decreased the binding between STAT3α and PTPN9 (better known as PTP-MEG2), a protein tyrosine phosphatase, thereby promoting the phosphorylation of STAT3α(Y705) and enhancing its nuclear translocation and DNA binding. Correlating with this, high STAT3β expression converts the prognostic value of pSTAT3α(Y705) from unfavorable to favorable in patients with ESCC. CONCLUSIONS STAT3β suppresses chemoresistance and cancer stemness by blocking the transcriptional activity of STAT3α. The paradoxical increase in pSTAT3α(Y705) induced by STAT3β carries important implications as to how the biologic and prognostic significance of STAT3 in cancers should be interpreted.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Carcinoma, Squamous Cell/diagnosis
- Carcinoma, Squamous Cell/drug therapy
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/mortality
- Cell Line, Tumor
- Disease Models, Animal
- Drug Resistance, Neoplasm/genetics
- Esophageal Neoplasms/diagnosis
- Esophageal Neoplasms/drug therapy
- Esophageal Neoplasms/genetics
- Esophageal Neoplasms/metabolism
- Esophageal Neoplasms/mortality
- Esophageal Squamous Cell Carcinoma
- Gene Expression Regulation, Neoplastic
- Humans
- Immunohistochemistry
- Models, Biological
- Neoplastic Stem Cells/metabolism
- Oncogene Proteins
- Phosphorylation
- Prognosis
- Protein Multimerization
- Protein Tyrosine Phosphatases/metabolism
- STAT3 Transcription Factor/chemistry
- STAT3 Transcription Factor/genetics
- STAT3 Transcription Factor/metabolism
- Transcriptional Activation
- Tumor Suppressor Proteins
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Hai-Feng Zhang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, China. Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Ye Chen
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China
| | - Chengsheng Wu
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Zhi-Yong Wu
- Department of Tumor Surgery, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou, Guangdong, China
| | - David J Tweardy
- Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Abdulraheem Alshareef
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Lian-Di Liao
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China
| | - Yu-Jie Xue
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China
| | - Jian-Yi Wu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, China
| | - Bo Chen
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China
| | - Xiu-E Xu
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China
| | - Keshav Gopal
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Nidhi Gupta
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - En-Min Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, China.
| | - Li-Yan Xu
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, China.
| | - Raymond Lai
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada. Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada. DynaLIFEDX Medical Laboratories, Edmonton, Alberta, Canada.
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32
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Abstract
The STAT3 is often dysregulated in genitourinary tumors. In prostate cancer, STAT3 activation correlates with Gleason score and pathological stage and modulates cancer stem cells and epithelial-mesenchymal transition. In addition, STAT3 promotes the progression from carcinoma in situ to invasive bladder cancer and modulates renal cell carcinoma angiogenesis by increasing the expression of HIF1α and VEGF. STAT3 is also involved in the response to tyrosine kinase inhibitors sunitinib and axitinib, in patients with metastatic renal cell carcinoma, and to second-generation androgen receptor inhibitor enzalutamide in patients with advanced prostate cancer. In this review, we describe the role of STAT3 in genitourinary tumors, thus describing its potential for future therapeutic strategies.
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Lewis KM, Bharadwaj U, Eckols TK, Kolosov M, Kasembeli MM, Fridley C, Siller R, Tweardy DJ. Small-molecule targeting of signal transducer and activator of transcription (STAT) 3 to treat non-small cell lung cancer. Lung Cancer 2015; 90:182-90. [PMID: 26410177 PMCID: PMC4619129 DOI: 10.1016/j.lungcan.2015.09.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/14/2015] [Accepted: 09/14/2015] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Lung cancer is the leading cause of cancer death in both men and women. Non-small cell lung cancer (NSCLC) has an overall 5-year survival rate of 15%. While aberrant STAT3 activation has previously been observed in NSCLC, the scope of its contribution is uncertain and agents that target STAT3 for treatment are not available clinically. METHODS We determined levels of activated STAT3 (STAT3 phosphorylated on Y705, pSTAT3) and the two major isoforms of STAT3 (α and β) in protein extracts of 8 NSCLC cell lines, as well as the effects of targeting STAT3 in vitro and in vivo in NSCLC cells using short hairpin (sh) RNA and two novel small-molecule STAT3 inhibitors, C188-9 and piperlongumine (PL). RESULTS Levels of pSTAT3, STAT3α, and STATβ were increased in 7 of 8 NSCLC cell lines. Of note, levels of pSTAT3 were tightly correlated with levels of STAT3β, but not STAT3α. Targeting of STAT3 in A549 cells using shRNA decreased tSTAT3 by 75%; this was accompanied by a 47-78% reduction in anchorage-dependent and anchorage-independent growth and a 28-45% reduction in mRNA levels for anti-apoptotic STAT3 gene targets. C188-9 and PL (@30 μM) each reduced pSTAT3 levels in all NSCLC cell lines tested by ≥50%, reduced anti-apoptotic protein mRNA levels by 25-60%, and reduced both anchorage-dependent and anchorage-independent growth of NSCLC cell lines with IC50 values ranging from 3.06 to 52.44 μM and 0.86 to 11.66 μM, respectively. Treatment of nude mice bearing A549 tumor xenografts with C188-9 or PL blocked tumor growth and reduced levels of pSTAT3 and mRNA encoding anti-apoptotic proteins. CONCLUSION STAT3 is essential for growth of NSCLC cell lines and tumors and its targeting using C188-9 or PL may be a useful strategy for treatment.
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Affiliation(s)
- Katherine M Lewis
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Uddalak Bharadwaj
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - T Kris Eckols
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Mikhail Kolosov
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Moses M Kasembeli
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Colleen Fridley
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Ricardo Siller
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - David J Tweardy
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
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Kramer AH, Kadye R, Houseman PS, Prinsloo E. Mitochondrial STAT3 and reactive oxygen species: A fulcrum of adipogenesis? JAKSTAT 2015; 4:e1084084. [PMID: 27127727 DOI: 10.1080/21623996.2015.1084084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/07/2015] [Accepted: 08/11/2015] [Indexed: 02/08/2023] Open
Abstract
The balance between cellular lineages can be controlled by reactive oxygen species (ROS). Cellular differentiation into adipocytes is highly dependent on the production of ROS to initiate the process through activation of multiple interlinked factors that stimulate mitotic clonal expansion and cellular maturation. The signal transducer and activator of transcription family of signaling proteins have accepted roles in adipogenesis and associated lipogenesis. Non-canonical mitochondrial localization of STAT3 and other members of the STAT family however opens up new avenues for investigation of its role in the aforementioned processes. Following recent observations of differences in mitochondrially localized serine 727 phosphorylated STAT3 (mtSTAT3-pS727) in preadipocytes and adipocytes, here, we hypothesize and speculate further on the role of mitochondrial STAT3 in adipogenesis.
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Affiliation(s)
- Adam H Kramer
- Biotechnology Innovation Center; Rhodes University ; Grahamstown, South Africa
| | - Rose Kadye
- Biotechnology Innovation Center; Rhodes University ; Grahamstown, South Africa
| | | | - Earl Prinsloo
- Biotechnology Innovation Center; Rhodes University ; Grahamstown, South Africa
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Sgrignani J, Olsson S, Ekonomiuk D, Genini D, Krause R, Catapano CV, Cavalli A. Molecular Determinants for Unphosphorylated STAT3 Dimerization Determined by Integrative Modeling. Biochemistry 2015; 54:5489-501. [DOI: 10.1021/bi501529x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Jacopo Sgrignani
- Institute of Research in Biomedicine (IRB) and Universitá della Svizzera italiana (USI), Via Vincenzo
Vela 6, CH-6500 Bellinzona, Switzerland
| | - Simon Olsson
- Institute of Research in Biomedicine (IRB) and Universitá della Svizzera italiana (USI), Via Vincenzo
Vela 6, CH-6500 Bellinzona, Switzerland
- Laboratorium
für Physikalische Chemie, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Dariusz Ekonomiuk
- Institute of Research in Biomedicine (IRB) and Universitá della Svizzera italiana (USI), Via Vincenzo
Vela 6, CH-6500 Bellinzona, Switzerland
| | - Davide Genini
- IOR Institute of Oncology Research, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland
| | - Rolf Krause
- Institute
of Computational Science, Faculty of Informatics, Universitá della Svizzera Italiana (USI), Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland
| | - Carlo V. Catapano
- IOR Institute of Oncology Research, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland
| | - Andrea Cavalli
- Institute of Research in Biomedicine (IRB) and Universitá della Svizzera italiana (USI), Via Vincenzo
Vela 6, CH-6500 Bellinzona, Switzerland
- Department
of Chemistry, University of Cambridge, Lansfield Road, Cambridge CB2 1EW, U.K
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Vogel TP, Milner JD, Cooper MA. The Ying and Yang of STAT3 in Human Disease. J Clin Immunol 2015; 35:615-23. [PMID: 26280891 DOI: 10.1007/s10875-015-0187-8] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 07/29/2015] [Indexed: 01/06/2023]
Abstract
The transcription factor signal transducer and activator of transcription 3 (STAT3) is a critical regulator of multiple, diverse cellular processes. Heterozgyous, germline, loss-of-function mutations in STAT3 lead to the primary immune deficiency Hyper-IgE syndrome. Heterozygous, somatic, gain-of-function mutations in STAT3 have been reported in malignancy. Recently, germline, heterozygous mutations in STAT3 that confer a gain-of-function have been discovered and result in early-onset, multi-organ autoimmunity. This review summarizes what is known about the role of STAT3 in human disease.
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Affiliation(s)
- Tiphanie P Vogel
- Department of Pediatrics, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Department of Internal Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Joshua D Milner
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Megan A Cooper
- Department of Pediatrics, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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Turton KB, Annis DS, Rui L, Esnault S, Mosher DF. Ratios of Four STAT3 Splice Variants in Human Eosinophils and Diffuse Large B Cell Lymphoma Cells. PLoS One 2015; 10:e0127243. [PMID: 25984943 PMCID: PMC4436176 DOI: 10.1371/journal.pone.0127243] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/13/2015] [Indexed: 01/09/2023] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) is a key mediator of leukocyte differentiation and proliferation. The 3' end of STAT3 transcripts is subject to two alternative splicing events. One results in either full-length STAT3α or in STAT3β, which lacks part of the C-terminal transactivation domain. The other is at a tandem donor (5') splice site and results in the codon for Ser-701 being included (S) or excluded (ΔS). Despite the proximity of Ser-701 to the site of activating phosphorylation at Tyr-705, ΔS/S splicing has barely been studied. Sequencing of cDNA from purified eosinophils revealed the presence of four transcripts (S-α, ΔS-α, S-β, and ΔS-β) rather than the three reported in publically available databases from which ΔS-β is missing. To gain insight into regulation of the two alternative splicing events, we developed a quantitative(q) PCR protocol to compare transcript ratios in eosinophils in which STAT3 is upregulated by cytokines, activated B cell diffuse large B cell Lymphoma (DLBCL) cells in which STAT3 is dysregulated, and in germinal center B cell-like DLBCL cells in which it is not. With the exception of one line of activated B cell DLCBL cells, the four variants were found in roughly the same ratios despite differences in total levels of STAT3 transcripts. S-α was the most abundant, followed by S-β. ΔS-α and ΔS-β together comprised 15.6±4.0 % (mean±SD, n=21) of the total. The percentage of STAT3β variants that were ΔS was 1.5-fold greater than of STAT3α variants that were ΔS. Inspection of Illumina’s “BodyMap” RNA-Seq database revealed that the ΔS variant accounts for 10-26 % of STAT3 transcripts across 16 human tissues, with less variation than three other genes with the identical tandem donor splice site sequence. Thus, it seems likely that all cells contain the S-α, ΔS-α, S-β, and ΔS-β variants of STAT3.
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Affiliation(s)
- Keren B. Turton
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Douglas S. Annis
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Lixin Rui
- Department of Medicine at University of Wisconsin-Madison, Madison, WI, United States of America
| | - Stephane Esnault
- Department of Medicine at University of Wisconsin-Madison, Madison, WI, United States of America
| | - Deane F. Mosher
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Medicine at University of Wisconsin-Madison, Madison, WI, United States of America
- * E-mail:
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Kramer AH, Edkins AL, Hoppe HC, Prinsloo E. Dynamic Mitochondrial Localisation of STAT3 in the Cellular Adipogenesis Model 3T3-L1. J Cell Biochem 2015; 116:1232-40. [DOI: 10.1002/jcb.25076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/19/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Adam H. Kramer
- Biomedical Biotechnology Research Unit; Biotechnology Innovation Centre; Rhodes University; PO Box 94 Grahamstown 6140 South Africa
| | - Adrienne L. Edkins
- Department of Biochemistry and Microbiology; Biomedical Biotechnology Research Unit; Rhodes University; PO Box 94 Grahamstown 6140 South Africa
| | - Heinrich C. Hoppe
- Department of Biochemistry and Microbiology; Rhodes University; PO Box 94 Grahamstown 6140 South Africa
| | - Earl Prinsloo
- Biomedical Biotechnology Research Unit; Biotechnology Innovation Centre; Rhodes University; PO Box 94 Grahamstown 6140 South Africa
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Dicay MS, Hirota CL, Ronaghan NJ, Peplowski MA, Zaheer RS, Carati CA, MacNaughton WK. Interferon-γ suppresses intestinal epithelial aquaporin-1 expression via Janus kinase and STAT3 activation. PLoS One 2015; 10:e0118713. [PMID: 25793528 PMCID: PMC4405000 DOI: 10.1371/journal.pone.0118713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/09/2015] [Indexed: 12/29/2022] Open
Abstract
Inflammatory bowel diseases are associated with dysregulated electrolyte and water transport and resultant diarrhea. Aquaporins are transmembrane proteins that function as water channels in intestinal epithelial cells. We investigated the effect of the inflammatory cytokine, interferon-γ, which is a major player in inflammatory bowel diseases, on aquaporin-1 expression in a mouse colonic epithelial cell line, CMT93. CMT93 monolayers were exposed to 10 ng/mL interferon-γ and aquaporin-1 mRNA and protein expressions were measured by real-time PCR and western blot, respectively. In other experiments, CMT93 cells were pretreated with inhibitors or were transfected with siRNA to block the effects of Janus kinases, STATs 1 and 3, or interferon regulatory factor 2, prior to treatment with interferon-γ. Interferon-γ decreased aquaporin-1 expression in mouse intestinal epithelial cells in a manner that did not depend on the classical STAT1/JAK2/IRF-1 pathway, but rather, on an alternate Janus kinase (likely JAK1) as well as on STAT3. The pro-inflammatory cytokine, interferon-γ may contribute to diarrhea associated with intestinal inflammation in part through regulation of the epithelial aquaporin-1 water channel via a non-classical JAK/STAT receptor signalling pathway.
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Affiliation(s)
- Michael S Dicay
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
| | - Christina L Hirota
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
| | - Natalie J Ronaghan
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
| | - Michael A Peplowski
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
| | - Raza S Zaheer
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
| | - Colin A Carati
- Department of Anatomy and Histology, Flinders University, Bedford Park, Australia
| | - Wallace K MacNaughton
- Inflammation Research Network and Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
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Santoni M, Massari F, Del Re M, Ciccarese C, Piva F, Principato G, Montironi R, Santini D, Danesi R, Tortora G, Cascinu S. Investigational therapies targeting signal transducer and activator of transcription 3 for the treatment of cancer. Expert Opin Investig Drugs 2015; 24:809-24. [PMID: 25746129 DOI: 10.1517/13543784.2015.1020370] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Signal transducer and activator of transcription 3 (STAT3) mediates the expression of a variety of genes in response to cell stimuli and thus plays a key role in several cellular processes such as cell growth and apoptosis. Deregulation of the STAT3 activity has been shown in many malignancies, including breast, head and neck, prostate, pancreas, ovarian and brain cancers and melanoma. Thus, STAT3 may represent an ideal target for cancer therapy. AREAS COVERED The authors review recent data on the role of STAT3 in tumor initiation and progression, as well as the ongoing clinical trials in cancer patients. The content includes information derived from trial databases, regulatory authorities and scientific literature. EXPERT OPINION Targeting STAT3 activation leads to the inhibition of tumor growth and metastasis both in vitro and in vivo without affecting normal cells; this suggests that STAT3 could be a valid molecular target for cancer therapy. Extensive clinical research is trying to find anti-STAT3 agents with high single-agent activity. The identification and development of novel drugs that can target deregulated STAT3 activation effectively is both a scientific and clinical challenge that needs to be addressed in the near future.
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Affiliation(s)
- Matteo Santoni
- Polytechnic University of the Marche Region, Medical Oncology, AOU Ospedali Riuniti , via Conca 71, 60126 Ancona , Italy +39 0715964263 ; +39 0715964269 ;
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Bharadwaj U, Kasembeli MM, Eckols TK, Kolosov M, Lang P, Christensen K, Edwards DP, Tweardy DJ. Monoclonal Antibodies Specific for STAT3β Reveal Its Contribution to Constitutive STAT3 Phosphorylation in Breast Cancer. Cancers (Basel) 2014; 6:2012-34. [PMID: 25268166 PMCID: PMC4276954 DOI: 10.3390/cancers6042012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/15/2014] [Accepted: 09/17/2014] [Indexed: 12/04/2022] Open
Abstract
Since its discovery in mice and humans 19 years ago, the contribution of alternatively spliced Stat3, Stat3β, to the overall functions of Stat3 has been controversial. Tyrosine-phosphorylated (p) Stat3β homodimers are more stable, bind DNA more avidly, are less susceptible to dephosphorylation, and exhibit distinct intracellular dynamics, most notably markedly prolonged nuclear retention, compared to pStat3α homodimers. Overexpression of one or the other isoform in cell lines demonstrated that Stat3β acted as a dominant-negative of Stat3α in transformation assays; however, studies with mouse strains deficient in one or the other isoform indicated distinct contributions of Stat3 isoforms to inflammation. Current immunological reagents cannot differentiate Stat3β proteins derived from alternative splicing vs. proteolytic cleavage of Stat3α. We developed monoclonal antibodies that recognize the 7 C-terminal amino acids unique to Stat3β (CT7) and do not cross-react with Stat3α. Immunoblotting studies revealed that levels of Stat3β protein, but not Stat3α, in breast cancer cell lines positively correlated with overall pStat3 levels, suggesting that Stat3β may contribute to constitutive Stat3 activation in this tumor system. The ability to unambiguously discriminate splice alternative Stat3β from proteolytic Stat3β and Stat3α will provide new insights into the contribution of Stat3β vs. Stat3α to oncogenesis, as well as other biological and pathological processes.
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Affiliation(s)
- Uddalak Bharadwaj
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Moses M Kasembeli
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
| | - T Kris Eckols
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Mikhail Kolosov
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Paul Lang
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Kurt Christensen
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Dean P Edwards
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - David J Tweardy
- Section of Infectious Disease, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
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Marino F, Orecchia V, Regis G, Musteanu M, Tassone B, Jon C, Forni M, Calautti E, Chiarle R, Eferl R, Poli V. STAT3β controls inflammatory responses and early tumor onset in skin and colon experimental cancer models. Am J Cancer Res 2014; 4:484-494. [PMID: 25232490 PMCID: PMC4163613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/17/2014] [Indexed: 06/03/2023] Open
Abstract
Chronic inflammation is a well-recognized pathogenic factor in tumor initiation and progression. Mice lacking the pro-oncogenic transcription factor STAT3 were shown to be protected from both colitis-associated and epidermal cancers induced by the AOM/DSS and DMBA/TPA protocols, respectively. However, these murine models did not distinguish between the two STAT3 isoforms, the full-length STAT3α, believed to exert most pro-oncogenic functions attributed to STAT3, and the shorter STAT3β, often referred to as a dominant-negative, but possessing specific transcriptional activities. Here we assessed the contribution of STAT3β to inflammation-driven tumorigenesis making use of mice lacking this isoform, but still expressing STAT3α (STAT3(Δβ/Δβ)). We show that the lack of STAT3β leads to exacerbated acute responses to both TPA and DSS, thus confirming its anti-inflammatory role. Enhanced inflammation correlates with earlier tumor onset in both the epidermis and the intestine in STAT3(Δβ/Δβ) mice. In contrast, overall tumor development and final tumor burden were unaffected. These results suggest that STAT3β, by limiting inflammation during the initial phases of tumorigenesis, contributes to tissue homeostasis and counteracts malignant transformation and initial tumor growth. Accordingly, the balance between the two STAT3 isoforms, likely determined by the complex signaling networks shaping the tumor microenvironment and driving tumor transformation and progression, is apparently crucial to determine the initial tumor transformation rates in inflammation-associated cancers.
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Affiliation(s)
- Francesca Marino
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Valeria Orecchia
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Gabriella Regis
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Monica Musteanu
- Spanish National Cancer Research Centre (CNIO)28029 Madrid, Spain
| | - Beatrice Tassone
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Cristina Jon
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Marco Forni
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Enzo Calautti
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
| | - Roberto Chiarle
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
- Departmen of Pathology, Children’s Hospital Boston and Harvard Medical School02115 Boston, USA.
| | - Robert Eferl
- Medical University Vienna & Comprehensive Cancer Center (CCC), Institute for Cancer ResearchA-1090 Vienna, Austria
| | - Valeria Poli
- Department of Molecular Biotechnology and Health Sciences, University of TurinTurin, 10126, Italy
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STAT3 in Cancer-Friend or Foe? Cancers (Basel) 2014; 6:1408-40. [PMID: 24995504 PMCID: PMC4190548 DOI: 10.3390/cancers6031408] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 12/25/2022] Open
Abstract
The roles and significance of STAT3 in cancer biology have been extensively studied for more than a decade. Mounting evidence has shown that constitutive activation of STAT3 is a frequent biochemical aberrancy in cancer cells, and this abnormality directly contributes to tumorigenesis and shapes many malignant phenotypes in cancer cells. Nevertheless, results from more recent experimental and clinicopathologic studies have suggested that STAT3 also can exert tumor suppressor effects under specific conditions. Importantly, some of these studies have demonstrated that STAT3 can function either as an oncoprotein or a tumor suppressor in the same cell type, depending on the specific genetic background or presence/absence of specific coexisting biochemical defects. Thus, in the context of cancer biology, STAT3 can be a friend or foe. In the first half of this review, we will highlight the “evil” features of STAT3 by summarizing its oncogenic functions and mechanisms. The differences between the canonical and non-canonical pathway will be highlighted. In the second half, we will summarize the evidence supporting that STAT3 can function as a tumor suppressor. To explain how STAT3 may mediate its tumor suppressor effects, we will discuss several possible mechanisms, one of which is linked to the role of STAT3β, one of the two STAT3 splicing isoforms. Taken together, it is clear that the roles of STAT3 in cancer are multi-faceted and far more complicated than one appreciated previously. The new knowledge has provided us with new approaches and strategies when we evaluate STAT3 as a prognostic biomarker or therapeutic target.
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Ng IHW, Bogoyevitch MA, Jans DA. Cytokine-induced slowing of STAT3 nuclear import; faster basal trafficking of the STAT3β isoform. Traffic 2014; 15:946-60. [PMID: 24903907 DOI: 10.1111/tra.12181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 01/01/2023]
Abstract
The STAT3 signal transducer and activator of transcription is a key mediator of gene transcription in response to cytokines such as oncostatin M (OSM). We performed direct live cell imaging of GFP-tagged STAT3 proteins for the first time, showing transient relocalization of STAT3α to the nucleus following OSM exposure, in contrast to sustained nuclear relocalization of the shorter STAT3β spliceform. To explore this further, we applied fluorescence recovery after photobleaching (FRAP) to determine the nuclear import kinetics of STAT3α and β, as well as of a C-terminal truncation derivative STAT3ΔC comprising only the sequence shared by the spliceforms, in the absence or presence of OSM. The rates of basal nuclear import for STAT3β and STAT3ΔC were significantly faster than those for STAT3α. Strikingly, OSM slowed the import rates of all the three STAT3 proteins, whereas the import rates of GFP alone or a classical importin-mediated cargo were unaffected, with analysis of Y705F mutant derivatives for all the three STAT3 constructs, or of a S727A mutant within the unique C-terminus of STAT3α, reinforcing the contribution of specific phosphorylation to the cytokine-stimulated changes. The results introduce a new paradigm where cytokine treatment prolongs nuclear retention simultaneous with decreasing rather than increasing the rate of nuclear import.
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Affiliation(s)
- Ivan H W Ng
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, 3010, Australia
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Qi QR, Yang ZM. Regulation and function of signal transducer and activator of transcription 3. World J Biol Chem 2014; 5:231-239. [PMID: 24921012 PMCID: PMC4050116 DOI: 10.4331/wjbc.v5.i2.231] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 01/07/2014] [Accepted: 01/20/2014] [Indexed: 02/05/2023] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3), a member of the STAT family, is a key regulator of many physiological and pathological processes. Significant progress has been made in understanding the transcriptional control, posttranslational modification, cellular localization and functional regulation of STAT3. STAT3 can translocate into the nucleus and bind to specific promoter sequences, thereby exerting transcriptional regulation. Recent studies have shown that STAT3 can also translocate into mitochondria, participating in aerobic respiration and apoptosis. In addition, STAT3 plays an important role in inflammation and tumorigenesis by regulating cell proliferation, differentiation and metabolism. Conditional knockout mouse models make it possible to study the physiological function of STAT3 in specific tissues and organs. This review summarizes the latest advances in the understanding of the expression, regulation and function of STAT3 in physiological and tumorigenic processes.
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Ng IHW, Yeap YYC, Ong LSR, Jans DA, Bogoyevitch MA. Oxidative stress impairs multiple regulatory events to drive persistent cytokine-stimulated STAT3 phosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:483-94. [PMID: 24286865 DOI: 10.1016/j.bbamcr.2013.11.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/31/2013] [Accepted: 11/19/2013] [Indexed: 12/30/2022]
Abstract
Although cytokine-driven STAT3 phosphorylation and activation are often transient, persistent activation of STAT3 is a hallmark of a range of pathologies and underpins altered transcriptional responses. As triggers in disease frequently include combined increases in inflammatory cytokine and reactive oxygen species levels, we report here how oxidative stress impacts on cytokine-driven STAT3 signal transduction events. In the model system of murine embryonic fibroblasts (MEFs), combined treatment with the interleukin-6 family cytokine Leukemia Inhibitory Factor (LIF) and hydrogen peroxide (H2O2) drove persistent STAT3 phosphorylation whereas STAT3 phosphorylation increased only transiently in response to LIF alone and was not increased by H2O2 alone. Surprisingly, increases in transcript levels of the direct STAT3 gene target SOCS3 were delayed during the combined LIF + H2O2 treatment, leading us to probe the impact of oxidative stress on STAT3 regulatory events. Indeed, LIF + H2O2 prolonged JAK activation, delayed STAT3 nuclear localisation, and caused relocalisation of nuclear STAT3 phosphatase TC-PTP (TC45) to the cytoplasm. In exploring the nuclear import/ export pathways, we observed disruption of nuclear/cytoplasmic distributions of Ran and importin-alpha3 in cells exposed to H2O2 and the resultant reduced nuclear trafficking of Classical importin-alpha/3-dependent protein cargoes. CRM1-mediated nuclear export persisted despite the oxidative stress insult, with sustained STAT3 Y705 phosphorylation enhancing STAT3 nuclear residency. Our studies thus reveal for the first time the striking impact of oxidative stress to sustain STAT3 phosphorylation and nuclear retention following disruption of multiple regulatory events, with significant implications for STAT3 function.
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Ng IHW, Jans DA, Bogoyevitch MA. Hyperosmotic stress sustains cytokine-stimulated phosphorylation of STAT3, but slows its nuclear trafficking and impairs STAT3-dependent transcription. Cell Signal 2014; 26:815-24. [PMID: 24394455 DOI: 10.1016/j.cellsig.2013.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Accepted: 12/22/2013] [Indexed: 11/16/2022]
Abstract
Persistent STAT3 phosphorylation and nuclear retention are hallmarks of a range of pathologies suggesting the importance of STAT3 transcriptional responses in disease progression. Since hyperosmotic stress (HOS) is a hallmark of diseases such as diabetes and asthma, we analysed the impact of HOS on cytokine-stimulated STAT3 signalling. In contrast to transient STAT3 Y705 and S727 phosphorylation in murine embryonic fibroblasts (MEFs) stimulated by the interleukin-6 family cytokine, leukemia inhibitory factor (LIF), under non-stress conditions, HOS induced by sorbitol treatment increased STAT3 S727 but not Y705 phosphorylation. Strikingly, combined LIF+HOS treatment stimulated persistent STAT3 Y705 and S727 phosphorylation and nuclear localisation, but STAT3 nuclear accumulation was slowed during HOS, likely reflecting the mislocalisation of Ran and importin-α3 during HOS that also reduced the nuclear localisation of classical importin-α/β-recognised nuclear import cargoes. Strikingly, combined LIF+HOS exposure, even though stimulating STAT3 phosphorylation and nuclear accumulation did not elicit a transcriptional output, as demonstrated by qPCR analyses of its target genes SOCS3 and c-Fos. Our analysis thus shows for the first time that HOS can disconnect nuclear, phosphorylated STAT3 from transcriptional outcomes, and emphasizes the importance of assessing STAT3 target gene changes in addition to STAT3 phosphorylation status and localisation.
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Affiliation(s)
- Ivan H W Ng
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia; Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - David A Jans
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia.
| | - Marie A Bogoyevitch
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia.
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Zouein FA, Kurdi M, Booz GW. Dancing rhinos in stilettos: The amazing saga of the genomic and nongenomic actions of STAT3 in the heart. JAKSTAT 2013; 2:e24352. [PMID: 24069556 PMCID: PMC3772108 DOI: 10.4161/jkst.24352] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/18/2013] [Accepted: 03/18/2013] [Indexed: 01/15/2023] Open
Abstract
A substantial body of evidence has shown that signal transducer and activator of transcription 3 (STAT3) has an important role in the heart in protecting the myocardium from ischemia and oxidative stress. These actions are attributed to STAT3 functioning as a transcription factor in upregulating cardioprotective genes. Loss of STAT3 has been implicated as well in the pathogenesis of heart failure and, in that context and in addition to the loss of a cardioprotective gene program, nuclear STAT3 has been identified as a transcriptional repressor important for the normal functioning of the ubiquitin-proteasome system for protein degradation. The later finding establishes a genomic role for STAT3 in controlling cellular homeostasis in cardiac myocytes independent of stress. Surprisingly, although a well-studied area, very few downstream gene targets of STAT3 in the heart have been definitively identified. In addition, STAT3 is now known to induce gene expression by noncanonical means that are not well characterized in the heart. On the other hand, recent evidence has shown that STAT3 has important nongenomic actions in cardiac myocytes that affect microtubule stability, mitochondrial respiration, and autophagy. These extranuclear actions of STAT3 involve protein–protein interactions that are incompletely understood, as is their regulation in both the healthy and injured heart. Moreover, how the diverse genomic and nongenomic actions of STAT3 crosstalk with each other is unchartered territory. Here we present an overview of what is and is not known about both the genomic and nongenomic actions of STAT3 in the heart from a structure-function perspective that focuses on the impact of posttranslational modifications and oxidative stress in regulating the actions and interactions of STAT3. Even though we have learnt a great deal about the role played by STAT3 in the heart, much more awaits to be discovered.
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Affiliation(s)
- Fouad A Zouein
- Department of Pharmacology and Toxicology; School of Medicine; and The Jackson Center for Heart Research at UMMC; The Cardiovascular-Renal Research Center; The University of Mississippi Medical Center; Jackson, MS USA
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