1
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Kim SJ, Cho NC, Hahn YI, Kim SH, Fang X, Surh YJ. STAT3 as a Potential Target for Tumor Suppressive Effects of 15-Deoxy-Δ 12,14-prostaglandin J 2 in Triple Negative Breast Cancer. J Cancer Prev 2021; 26:207-217. [PMID: 34703823 PMCID: PMC8511581 DOI: 10.15430/jcp.2021.26.3.207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 12/24/2022] Open
Abstract
STAT3 plays a prominent role in proliferation and survival of tumor cells. Thus, STAT3 has been considered to be a prime target for development of anti-cancer therapeutics. The electrophilic cyclopentenone prostaglandin,15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has been well recognized for its capability to modulate intracellular signaling pathways involved in cancer cell growth and progression. We previously reported that 15d-PGJ2 had potent cytotoxicity against harvey-ras transformed human mammary epithelial cells through direct interaction with STAT3. In this study, we have attempted to verify the inhibitory effects of 15d-PGJ2 on STAT3 signaling in human breast tumor cells. The triple negative breast cancer cell lines, MDA-MB-231 and MDA-MB-468 displaying constitutive phosphorylation of STAT3 on the tyrosine 705 (Tyr705) residue, underwent apoptosis upon inhibition of STAT3 by 15d-PGJ2. In contrast, estrogen receptor positive MCF-7 breast cancer cells that do not exhibit elevated STAT3 phosphorylation were much less susceptible to 15d-PGJ2-induced apoptosis as assessed by PARP cleavage. Furthermore, 15d-PGJ2 inhibited interleukin-6-induced tyrosine phosphorylation of STAT3 in LNCaP cells. According to molecular docking studies, 15d-PGJ2 may preferentially bind to the cysteine 259 residue (Cys259) present in the coiled-coil domain of STAT3. Site-directed mutagenesis of STAT3 identified Cys259 to be the critical amino acid for the 15d-PGJ2-induced apoptosis as well as epithelial-to-mesenchymal transition. Taken together, these findings suggest STAT3 inactivation through direct chemical modification of its Cys259 as a potential therapeutic approach for treatment of triple negative breast cancer treatment.
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Affiliation(s)
- Su-Jung Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Nam-Chul Cho
- Korea Chemical Bank, Korea Research Institute of Chemical Technology, Daejeon, Korea
| | - Young-Il Hahn
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science, Seoul National University, Seoul, Korea
| | - Seong Hoon Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Xizhu Fang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Young-Joon Surh
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science, Seoul National University, Seoul, Korea.,Cancer Research Institute, Seoul National University, Seoul, Korea
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2
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Liu Y, Liao S, Bennett S, Tang H, Song D, Wood D, Zhan X, Xu J. STAT3 and its targeting inhibitors in osteosarcoma. Cell Prolif 2020; 54:e12974. [PMID: 33382511 PMCID: PMC7848963 DOI: 10.1111/cpr.12974] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/21/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) is one of seven STAT family members involved with the regulation of cellular growth, differentiation and survival. STAT proteins are conserved among eukaryotes and are important for biological functions of embryogenesis, immunity, haematopoiesis and cell migration. STAT3 is widely expressed and located in the cytoplasm in an inactive form. STAT3 is rapidly and transiently activated by tyrosine phosphorylation by a range of signalling pathways, including cytokines from the IL‐6 family and growth factors, such as EGF and PDGF. STAT3 activation and subsequent dimer formation initiates nuclear translocation of STAT3 for the regulation of target gene transcription. Four STAT3 isoforms have been identified, which have distinct biological functions. STAT3 is considered a proto‐oncogene and constitutive activation of STAT3 is implicated in the development of various cancers, including multiple myeloma, leukaemia and lymphomas. In this review, we focus on recent progress on STAT3 and osteosarcoma (OS). Notably, STAT3 is overexpressed and associated with the poor prognosis of OS. Constitutive activation of STAT3 in OS appears to upregulate the expression of target oncogenes, leading to OS cell transformation, proliferation, tumour formation, invasion, metastasis, immune evasion and drug resistance. Taken together, STAT3 is a target for cancer therapy, and STAT3 inhibitors represent potential therapeutic candidates for the treatment of OS.
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Affiliation(s)
- Yun Liu
- Department of Spine and Osteopathic Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia.,Research Centre for Regenerative Medicine, Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Shijie Liao
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia.,Research Centre for Regenerative Medicine, Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China.,Department of Trauma Orthopedic and Hand Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Samuel Bennett
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Haijun Tang
- Department of Orthopedic, Guangxi hospital for nationalities, Nanning, Guangxi, China
| | - Dezhi Song
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia.,Research Centre for Regenerative Medicine, Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - David Wood
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Xinli Zhan
- Department of Spine and Osteopathic Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia.,Research Centre for Regenerative Medicine, Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Jiake Xu
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
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3
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La Sala G, Michiels C, Kükenshöner T, Brandstoetter T, Maurer B, Koide A, Lau K, Pojer F, Koide S, Sexl V, Dumoutier L, Hantschel O. Selective inhibition of STAT3 signaling using monobodies targeting the coiled-coil and N-terminal domains. Nat Commun 2020; 11:4115. [PMID: 32807795 PMCID: PMC7431413 DOI: 10.1038/s41467-020-17920-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 07/27/2020] [Indexed: 12/23/2022] Open
Abstract
The transcription factor STAT3 is frequently activated in human solid and hematological malignancies and remains a challenging therapeutic target with no approved drugs to date. Here, we develop synthetic antibody mimetics, termed monobodies, to interfere with STAT3 signaling. These monobodies are highly selective for STAT3 and bind with nanomolar affinity to the N-terminal and coiled-coil domains. Interactome analysis detects no significant binding to other STATs or additional off-target proteins, confirming their exquisite specificity. Intracellular expression of monobodies fused to VHL, an E3 ubiquitin ligase substrate receptor, results in degradation of endogenous STAT3. The crystal structure of STAT3 in complex with monobody MS3-6 reveals bending of the coiled-coil domain, resulting in diminished DNA binding and nuclear translocation. MS3-6 expression strongly inhibits STAT3-dependent transcriptional activation and disrupts STAT3 interaction with the IL-22 receptor. Therefore, our study establishes innovative tools to interfere with STAT3 signaling by different molecular mechanisms. STAT3 is an attractive therapeutic target but its homology with other STAT proteins complicates the development of selective inhibitors. Here, the authors develop monobodies with high affinity and selectivity for STAT3 and show that they can interfere with cellular STAT3 activity.
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Affiliation(s)
- Grégory La Sala
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École polytechnique fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland
| | - Camille Michiels
- Experimental Medicine Unit, De Duve Institute, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Tim Kükenshöner
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École polytechnique fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland
| | - Tania Brandstoetter
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Austria
| | - Barbara Maurer
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Austria
| | - Akiko Koide
- Department of Medicine, New York University School of Medicine, 522 1st Avenue, New York, 10016, NY, USA.,Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, 522 1st Avenue, New York, 10016, NY, USA
| | - Kelvin Lau
- Protein Crystallography Core Facility, School of Life Sciences, École polytechnique fédérale de Lausanne, Station 19, 1015, Lausanne, Switzerland
| | - Florence Pojer
- Protein Crystallography Core Facility, School of Life Sciences, École polytechnique fédérale de Lausanne, Station 19, 1015, Lausanne, Switzerland
| | - Shohei Koide
- Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, 522 1st Avenue, New York, 10016, NY, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 522 1st Avenue, New York, 10016, NY, USA
| | - Veronika Sexl
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Austria
| | - Laure Dumoutier
- Experimental Medicine Unit, De Duve Institute, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Oliver Hantschel
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École polytechnique fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland. .,Faculty of Medicine, Institute of Physiological Chemistry, Philipps-University of Marburg, Karl-von-Frisch-Straße 1, 35032, Marburg, Germany.
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4
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Shan Q, Li S, Cao Q, Yue C, Niu M, Chen X, Shi L, Li H, Gao S, Liang J, Yu R, Liu X. Inhibition of chromosomal region maintenance 1 suppresses the migration and invasion of glioma cells via inactivation of the STAT3/MMP2 signaling pathway. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:193-201. [PMID: 32392910 PMCID: PMC7193913 DOI: 10.4196/kjpp.2020.24.3.193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 01/07/2023]
Abstract
Chromosomal region maintenance 1 (CRM1) is associated with an adverse prognosis in glioma. We previously reported that CRM1 inhibition suppressed glioma cell proliferation both in vitro and in vivo. In this study, we investigated the role of CRM1 in the migration and invasion of glioma cells. S109, a novel reversible selective inhibitor of CRM1, was used to treat Human glioma U87 and U251 cells. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. The results showed that S109 significantly inhibited the migration and invasion of U87 and U251 cells. However, mutation of Cys528 in CRM1 abolished the inhibitory activity of S109 in glioma cells. Furthermore, we found that S109 treatment decreased the expression level and activity of MMP2 and reduced the level of phosphorylated STAT3 but not total STAT3. Therefore, the inhibition of migration and invasion induced by S109 may be associated with the downregulation of MMP2 activity and expression, and inactivation of the STAT3 signaling pathway. These results support our previous conclusion that inhibition of CRM1 is an attractive strategy for the treatment of glioma.
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Affiliation(s)
- Qianqian Shan
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Shengsheng Li
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Qiyu Cao
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Chenglong Yue
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Mingshan Niu
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
- Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Xiangyu Chen
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Lin Shi
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Huan Li
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Shangfeng Gao
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Jun Liang
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Rutong Yu
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
| | - Xuejiao Liu
- Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, China
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5
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de Araujo Junior RF, Eich C, Jorquera C, Schomann T, Baldazzi F, Chan AB, Cruz LJ. Ceramide and palmitic acid inhibit macrophage-mediated epithelial-mesenchymal transition in colorectal cancer. Mol Cell Biochem 2020; 468:153-168. [PMID: 32222879 PMCID: PMC7145792 DOI: 10.1007/s11010-020-03719-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 03/13/2020] [Indexed: 02/06/2023]
Abstract
Accumulating evidence indicates that ceramide (Cer) and palmitic acid (PA) possess the ability to modulate switching of macrophage phenotypes and possess anti-tumorigenic effects; however, the underlying molecular mechanisms are largely unknown. The aim of the present study was to investigate whether Cer and PA could induce switching of macrophage polarization from the tumorigenic M2- towards the pro-inflammatory M1-phenotype, and whether this consequently altered the potential of colorectal cancer cells to undergo epithelial–mesenchymal transition (EMT), a hallmark of tumor progression. Our study showed that Cer- and PA-treated macrophages increased expression of the macrophage 1 (M1)-marker CD68 and secretion of IL-12 and attenuated expression of the macrophage 2 (M2)-marker CD163 and IL-10 secretion. Moreover, Cer and PA abolished M2 macrophage-induced EMT and migration of colorectal cancer cells. At the molecular level, this coincided with inhibition of SNAI1 and vimentin expression and upregulation of E-cadherin. Furthermore, Cer and PA attenuated expression levels of IL-10 in colorectal cancer cells co-cultured with M2 macrophages and downregulated STAT3 and NF-κB expression. For the first time, our findings suggest the presence of an IL-10-STAT3-NF-κB signaling axis in colorectal cancer cells co-cultured with M2 macrophages, mimicking the tumor microenvironment. Importantly, PA and Cer were powerful inhibitors of this signaling axis and, consequently, EMT of colorectal cancer cells. These results contribute to our understanding of the immunological mechanisms that underlie the anti-tumorigenic effects of lipids for future combination with drugs in the therapy of colorectal carcinoma.
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Affiliation(s)
- Raimundo Fernandes de Araujo Junior
- Department of Morphology, Federal University of Rio Grande do Norte, Natal, RN, 59072-970, Brazil. .,Post-Graduation Programme in Structural and Functional Biology, Federal University of Rio Grande do Norte, Natal, RN, 59072-970, Brazil. .,Post-Graduation Programme in Health Science, Federal University of Rio Grande do Norte, Natal, RN, 59072-970, Brazil. .,Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands.
| | - Christina Eich
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Carla Jorquera
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Timo Schomann
- Percuros B.V., 2333 CL, Leiden, The Netherlands.,Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Fabio Baldazzi
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Alan B Chan
- Percuros B.V., 2333 CL, Leiden, The Netherlands.,Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Luis J Cruz
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
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6
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Yang J, Kunimoto H, Katayama B, Zhao H, Shiromizu T, Wang L, Ozawa T, Tomonaga T, Tsuruta D, Nakajima K. Phospho-Ser727 triggers a multistep inactivation of STAT3 by rapid dissociation of pY705-SH2 through C-terminal tail modulation. Int Immunol 2020; 32:73-88. [PMID: 31555812 PMCID: PMC10689346 DOI: 10.1093/intimm/dxz061] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 09/18/2019] [Indexed: 12/21/2022] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) is involved in many biological processes, including immunity and cancer. STAT3 becomes phosphorylated at Tyr705 and Ser727 on IL-6 stimulation. Phospho-Tyr705 (pY705) stabilizes the STAT3 dimer with reciprocal interactions between pY705 and the SH2 of the other molecule and phospho-Ser727 (pS727) accelerates pY705 dephosphorylation. We study how pS727 regulates STAT3 in both structural and biological perspectives. Using STAT3 reconstituted in HepG2-stat3-knockout cells, we show that pS727, together with a handshake N-terminal domain (NTD) interaction, causes rapid inactivation of STAT3 for pY705 dephosphorylation and a chromosome region maintenance 1 (CRM1)-independent nuclear export, which is critical for faithful STAT3 response to the cellular signals. The various N-terminal tags, GFP-related Ruby and FLAG, rendered the export CRM1-dependent and especially FLAG-tag caused nuclear accumulation of STAT3, indicating the presence of conformational changes in inactivation. Impaired reactivation of STAT3 by S727A or FLAG-tag delayed or inhibited the IL-6-induced saa1 mRNA expression, respectively. The detailed analysis of the pY705-SH2 structure identified the C-terminal tail (CTT) from L706 to P715 as a key regulator of the CTT-CTT intermolecular and the CTT-SH2 intramolecular interactions that support pY705-SH2 association. The functional studies using multiple STAT3 mutants indicated that the degree of the two interactions determines the stability of pY705-SH2 interaction. Importantly, Pro715 was critical for the pS727's destabilizing activity and the known phosphorylation and acetylation at the CTT structurally inhibited the pY705-SH2 interaction. Thus, pS727 triggers pY705-SH2 dissociation by weakening the supportive interactions likely through CTT modulation, inducing rapid cycles of STAT3 activation-inactivation for proper function of STAT3.
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Affiliation(s)
- Junhao Yang
- Department of Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Hiroyuki Kunimoto
- Department of Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Bumpei Katayama
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Hong Zhao
- Department of Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takashi Shiromizu
- Laboratory of Proteome Research, National Institute of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan
| | - Lingyu Wang
- Department of Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Toshiyuki Ozawa
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takeshi Tomonaga
- Laboratory of Proteome Research, National Institute of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan
| | - Daisuke Tsuruta
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Koichi Nakajima
- Department of Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
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7
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Sheng Z, Xu Y, Wang S, Yuan Y, Huang T, Lu P. XPO1-mediated nuclear export of RNF146 protects from angiotensin II-induced endothelial cellular injury. Biochem Biophys Res Commun 2018; 503:1544-1549. [PMID: 30029878 DOI: 10.1016/j.bbrc.2018.07.077] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 01/03/2023]
Abstract
Endothelial cells death induced by angiotensin II (Ang II) plays a role in vascular injury. RNF146 is identified as a E3 ubiquitin ligase, which promotes cell survival under many types of stresses. However, the role of RNF146 in endothelial cellular injury is unknown. In human umbilical vein endothelial cells (HUVECs), Ang II treatment led to cell death by oxidative stress and promoted RNF146 to accumulate in nucleus in time dependent manner. Nuclear export signal was found in the RNF146's sequence. The interaction between RNF146 and XPO1 was further confirmed by co-immunoprecipitation. Inhibition of XPO1 with KPT-185 increased the level of RNF146 in nucleus. The expression of XPO1 was suppressed responding to Ang II treatment. Overexpression of XPO1 facilitated the nuclear shuttling of RNF146, which protected from Ang II-induced cell death. Moreover, overexpression of RNF146 in HUVECs reduced the cell death induced by Ang II, whereas inhibition of XPO1 abolished the protective effect of RNF146. Therefore, our data demonstrated that RNF146 was a protective factor against cell death induced by AngII in human endothelial cells, which was dependent on XPO1-mediated nuclear export.
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Affiliation(s)
- Zhiyong Sheng
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Yun Xu
- Department of Emergency, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Shu Wang
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Ying Yuan
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Tieqiu Huang
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Peng Lu
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China.
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8
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Garg M, Kanojia D, Mayakonda A, Ganesan TS, Sadhanandhan B, Suresh S, S S, Nagare RP, Said JW, Doan NB, Ding LW, Baloglu E, Shacham S, Kauffman M, Koeffler HP. Selinexor (KPT-330) has antitumor activity against anaplastic thyroid carcinoma in vitro and in vivo and enhances sensitivity to doxorubicin. Sci Rep 2017; 7:9749. [PMID: 28852098 PMCID: PMC5575339 DOI: 10.1038/s41598-017-10325-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/07/2017] [Indexed: 12/21/2022] Open
Abstract
Anaplastic thyroid carcinoma (ATC) is one of the most lethal malignancies having no effective treatment. Exportin-1 (XPO1) is the key mediator of nuclear export of many tumor suppressor proteins and is overexpressed in human cancers. In this study, we examined the therapeutic potential of selinexor (XPO1 inhibitor) against human ATC cells both in vitro and in vivo. Here, we showed that XPO1 is robustly expressed in primary ATC samples and human ATC cell lines. Silencing of XPO1 by either shRNA or selinexor significantly reduced cellular growth and induced cell cycle arrest, apoptosis of ATC cells by altering the protein expression of cancer-related genes. Moreover, selinexor significantly inhibited tumor growth of ATC xenografts. Microarray analysis showed enrichment of DNA replication, cell cycle, cell cycle checkpoint and TNF pathways in selinexor treated ATC cells. Importantly, selinexor decreased AXL and GAS6 levels in CAL62 and HTH83 cells and suppressed the phosphorylation of downstream targets of AXL signaling such as AKT and P70S6K. Finally, a combination of selinexor with doxorubicin demonstrated a synergistic decrease in the cellular proliferation of several ATC cells. These results provide a rationale for investigating the efficacy of combining selinexor and doxorubicin therapy to improve the outcome of ATC patients.
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Affiliation(s)
- Manoj Garg
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore, Singapore.
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India.
| | - Deepika Kanojia
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore, Singapore
| | - Anand Mayakonda
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore, Singapore
| | - Trivadi S Ganesan
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India
| | - Bindhya Sadhanandhan
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India
| | - Sidhanth Suresh
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India
| | - Sneha S
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India
| | - Rohit P Nagare
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar, Chennai, India
| | - Jonathan W Said
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Ngan B Doan
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Ling-Wen Ding
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore, Singapore
| | | | | | | | - H Phillip Koeffler
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore, Singapore
- Division of Hematology/Oncology, Cedars-Sinai Medical Center, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
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9
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Garg M, Kanojia D, Mayakonda A, Said JW, Doan NB, Chien W, Ganesan TS, Huey LSC, Venkatachalam N, Baloglu E, Shacham S, Kauffman M, Koeffler HP. Molecular mechanism and therapeutic implications of selinexor (KPT-330) in liposarcoma. Oncotarget 2017; 8:7521-7532. [PMID: 27893412 PMCID: PMC5352339 DOI: 10.18632/oncotarget.13485] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/09/2016] [Indexed: 02/07/2023] Open
Abstract
Exportin-1 mediates nuclear export of multiple tumor suppressor and growth regulatory proteins. Aberrant expression of exportin-1 is noted in human malignancies, resulting in cytoplasmic mislocalization of its target proteins. We investigated the efficacy of selinexor against liposarcoma cells both in vitro and in vivo. Exportin-1 was highly expressed in liposarcoma samples and cell lines as determined by immunohistochemistry, western blot, and immunofluorescence assay. Knockdown of endogenous exportin-1 inhibited proliferation of liposarcoma cells. Selinexor also significantly decreased cell proliferation as well as induced cell cycle arrest and apoptosis of liposarcoma cells. The drug also significantly decreased tumor volumes and weights of liposarcoma xenografts. Importantly, selinexor inhibited insulin-like growth factor 1 (IGF1) activation of IGF-1R/AKT pathway through upregulation of insulin-like growth factor binding protein 5 (IGFBP5). Further, overexpression and knockdown experiments showed that IGFBP5 acts as a tumor suppressor and its expression was restored upon selinexor treatment of liposarcoma cells. Selinexor decreased aurora kinase A and B levels in these cells and inhibitors of these kinases suppressed the growth of the liposarcoma cells. Overall, our study showed that selinexor treatment restored tumor suppressive function of IGFBP5 and inhibited aurora kinase A and B in liposarcoma cells supporting the usefulness of selinexor as a potential therapeutic strategy for the treatment of this cancer.
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Affiliation(s)
- Manoj Garg
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar Chennai, India
| | - Deepika Kanojia
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore
| | - Anand Mayakonda
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore
| | - Jonathan W Said
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Ngan B Doan
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Wenwen Chien
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore
| | - Trivadi S Ganesan
- Department of Medical Oncology and Clinical Research, Cancer Institute (WIA), Adyar Chennai, India
| | | | | | | | | | | | - H. Phillip Koeffler
- Cancer Science Institute (CSI) of Singapore, National University of Singapore, Singapore
- Division of Hematology/Oncology, Cedars-Sinai Medical Center, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
- National University Cancer Institute, National University Hospital, Singapore, Singapore
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10
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Abstract
Signal transducers and activators of transcription 5 (STAT5a and STAT5b) are highly homologous proteins that are encoded by 2 separate genes and are activated by Janus-activated kinases (JAK) downstream of cytokine receptors. STAT5 proteins are activated by a wide variety of hematopoietic and nonhematopoietic cytokines and growth factors, all of which use the JAK-STAT signalling pathway as their main mode of signal transduction. STAT5 proteins critically regulate vital cellular functions such as proliferation, differentiation, and survival. The physiological importance of STAT5 proteins is underscored by the plethora of primary human tumors that have aberrant constitutive activation of these proteins, which significantly contributes to tumor cell survival and malignant progression of disease. STAT5 plays an important role in the maintenance of normal immune function and homeostasis, both of which are regulated by specific members of IL-2 family of cytokines, which share a common gamma chain (γ(c)) in their receptor complex. STAT5 critically mediates the biological actions of members of the γ(c) family of cytokines in the immune system. Essentially, STAT5 plays a critical role in the function and development of Tregs, and consistently activated STAT5 is associated with a suppression in antitumor immunity and an increase in proliferation, invasion, and survival of tumor cells. Thus, therapeutic targeting of STAT5 is promising in cancer.
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Affiliation(s)
- Aradhana Rani
- Department of Biomedical Sciences, University of Westminster , London, United Kingdom
| | - John J Murphy
- Department of Biomedical Sciences, University of Westminster , London, United Kingdom
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11
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Zouein FA, Altara R, Chen Q, Lesnefsky EJ, Kurdi M, Booz GW. Pivotal Importance of STAT3 in Protecting the Heart from Acute and Chronic Stress: New Advancement and Unresolved Issues. Front Cardiovasc Med 2015; 2:36. [PMID: 26664907 PMCID: PMC4671345 DOI: 10.3389/fcvm.2015.00036] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/12/2015] [Indexed: 12/25/2022] Open
Abstract
The transcription factor, signal transducer and activator of transcription 3 (STAT3), has been implicated in protecting the heart from acute ischemic injury under both basal conditions and as a crucial component of pre- and post-conditioning protocols. A number of anti-oxidant and antiapoptotic genes are upregulated by STAT3 via canonical means involving phosphorylation on Y705 and S727, although other incompletely defined posttranslational modifications are involved. In addition, STAT3 is now known to be present in cardiac mitochondria and to exert actions that regulate the electron transport chain, reactive oxygen species production, and mitochondrial permeability transition pore opening. These non-canonical actions of STAT3 are enhanced by S727 phosphorylation. The molecular basis for the mitochondrial actions of STAT3 is poorly understood, but STAT3 is known to interact with a critical subunit of complex I and to regulate complex I function. Dysfunctional complex I has been implicated in ischemic injury, heart failure, and the aging process. Evidence also indicates that STAT3 is protective to the heart under chronic stress conditions, including hypertension, pregnancy, and advanced age. Paradoxically, the accumulation of unphosphorylated STAT3 (U-STAT3) in the nucleus has been suggested to drive pathological cardiac hypertrophy and inflammation via non-canonical gene expression, perhaps involving a distinct acetylation profile. U-STAT3 may also regulate chromatin stability. Our understanding of how the non-canonical genomic and mitochondrial actions of STAT3 in the heart are regulated and coordinated with the canonical actions of STAT3 is rudimentary. Here, we present an overview of what is currently known about the pleotropic actions of STAT3 in the heart in order to highlight controversies and unresolved issues.
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Affiliation(s)
- Fouad A Zouein
- American University of Beirut Faculty of Medicine , Beirut , Lebanon
| | - Raffaele Altara
- Department of Pharmacology and Toxicology, School of Medicine, The University of Mississippi Medical Center , Jackson, MS , USA
| | - Qun Chen
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University , Richmond, VA , USA
| | - Edward J Lesnefsky
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University , Richmond, VA , USA ; Department of Biochemistry and Molecular Biology, Virginia Commonwealth University , Richmond, VA , USA ; McGuire Department of Veterans Affairs Medical Center , Richmond, VA , USA
| | - Mazen Kurdi
- Department of Pharmacology and Toxicology, School of Medicine, The University of Mississippi Medical Center , Jackson, MS , USA ; Department of Chemistry and Biochemistry, Faculty of Sciences, Lebanese University , Hadath , Lebanon
| | - George W Booz
- Department of Pharmacology and Toxicology, School of Medicine, The University of Mississippi Medical Center , Jackson, MS , USA
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12
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Cheng Y, Holloway MP, Nguyen K, McCauley D, Landesman Y, Kauffman MG, Shacham S, Altura RA. XPO1 (CRM1) inhibition represses STAT3 activation to drive a survivin-dependent oncogenic switch in triple-negative breast cancer. Mol Cancer Ther 2014; 13:675-86. [PMID: 24431073 PMCID: PMC3954411 DOI: 10.1158/1535-7163.mct-13-0416] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Inhibition of XPO1 (CRM1)-mediated nuclear export of multiple tumor suppressor proteins has been proposed as a novel cancer therapeutic strategy to turn off oncogenic signals and enhance tumor suppression. Survivin is a multifunctional protein with oncogenic properties when expressed in the cytoplasm that requires the XPO1-RanGTP complex for its nuclear export. We investigated the antitumor mechanisms of the drug-like selective inhibitors of nuclear export (SINE) XPO1 antagonists KPT-185, KPT-251 KPT-276, and KPT-330 in estrogen receptor-positive and triple-negative breast cancer (TNBC) cell lines and xenograft models of human breast tumors. KPT compounds significantly inhibited breast cancer cell growth and induced tumor cell death, both in vitro and in vivo. These drugs initially promoted survivin accumulation within tumor cell nuclei. However, their major in vitro effect was to decrease survivin cytoplasmic protein levels, correlating with the onset of apoptosis. XPO1 inhibition repressed Survivin transcription by inhibiting CREB-binding protein-mediated STAT3 acetylation, and blocking STAT3 binding to the Survivin promoter. In addition, caspase-3 was activated to cleave survivin, rendering it unavailable to bind X-linked inhibitor of apoptosis protein and block the caspase cascade. Collectively, these data demonstrate that XPO1 inhibition by SINE compounds represses STAT3 transactivation to block the selective oncogenic properties of survivin and supports their clinical use in TNBC.
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Affiliation(s)
- Yan Cheng
- Corresponding Author: Rachel A. Altura, Department of Pediatrics, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903.
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13
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A novel missense (M206K) STAT3 mutation in diffuse large B cell lymphoma deregulates STAT3 signaling. PLoS One 2013; 8:e67851. [PMID: 23861822 PMCID: PMC3701620 DOI: 10.1371/journal.pone.0067851] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/22/2013] [Indexed: 01/17/2023] Open
Abstract
Persistent STAT3 activation has been found in activated B-cell like diffuse large B cell tumors (DLBCL). To investigate whether genetic mutations play a role in aberrant STAT3 signaling in DLBCL, we bi-directionally sequenced all 24 exons of the STAT3 gene in DLBCL tumors (n = 40). We identified 2 novel point mutations in 2 separate (2/40; 5%) patients at exon 7 and 24. Point mutation 2552G>A was a silent mutation in the stop codon. Another heterozygous mutation 857T>A encoded a methionine substitution by lysine at codon 206 (M206K) in the coiled-coil domain of STAT3. We performed site directed mutagenesis to mutate wild type (WT) STAT3α and STAT3β at codon 206 and constructed stable cell lines by lentiviral transfection of STAT3αWT, STAT3αM206K, STAT3βWT and STAT3βM206K plasmids. The mutation was found to increase STAT3 phosphorylation in STAT3α mutant cell lines with no effect on the STAT3β mutant cell line. Transcriptional activation was also increased in the STAT3α mutant cells compared with STAT3α WT cells as detected by a luciferase reporter assay. Moreover, STAT3αM206K mutant cells were resistant to JAK2 pathway inhibition compared to STAT3α WT cells. These results indicate that missense mutations in STAT3 increase signaling through the JAK/STAT pathway. JAK2 inhibitors may be useful in the patient with this STAT3 mutation as well as those with pathway activation by other mechanisms.
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14
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Subramaniam A, Shanmugam MK, Perumal E, Li F, Nachiyappan A, Dai X, Swamy SN, Ahn KS, Kumar AP, Tan BKH, Hui KM, Sethi G. Potential role of signal transducer and activator of transcription (STAT)3 signaling pathway in inflammation, survival, proliferation and invasion of hepatocellular carcinoma. Biochim Biophys Acta Rev Cancer 2012; 1835:46-60. [PMID: 23103770 DOI: 10.1016/j.bbcan.2012.10.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/18/2012] [Accepted: 10/21/2012] [Indexed: 12/14/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most lethal malignancies, and is also the fourth most common cancer worldwide with around 700,000 new cases each year. Currently, first line chemotherapeutic drugs used for HCC include fluorouracil, cisplatin, doxorubicin, paclitaxel and mitomycin, but most of these are non-selective cytotoxic molecules with significant side effects. Sorafenib is the only approved targeted therapy by the U.S. Food and Drug Administration for HCC treatment, but patients suffer from various kinds of adverse effects, including hypertension. The signal-transducer-and-activator-of-transcription 3 (STAT3) protein, one of the members of STATs transcription factor family, has been implicated in signal transduction by different cytokines, growth factors and oncogenes. In normal cells, STAT3 activation is tightly controlled to prevent dysregulated gene transcription, whereas constitutively activated STAT3 plays an important role in tumorigenesis through the upregulation of genes involved in anti-apoptosis, proliferation and angiogenesis. Thus, pharmacologically safe and effective agents that can block STAT3 activation have the potential both for the prevention and treatment of HCC. In the present review, we discuss the possible role of STAT3 signaling cascade and its interacting partners in the initiation of HCC and also analyze the role of various STAT3 regulated genes in HCC progression, inflammation, survival, invasion and angiogenesis.
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Affiliation(s)
- Aruljothi Subramaniam
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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15
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Fillatre J, Delacour D, Van Hove L, Bagarre T, Houssin N, Soulika M, Veitia RA, Moreau J. Dynamics of the subcellular localization of RalBP1/RLIP through the cell cycle: the role of targeting signals and of protein-protein interactions. FASEB J 2012; 26:2164-74. [PMID: 22319010 DOI: 10.1096/fj.11-196451] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The small G protein Ras regulates many cell processes, such as gene expression, proliferation, apoptosis, and cell differentiation. Its mutations are associated with one-third of all cancers. Ras functions are mediated, at least in part, by Ral proteins and their downstream effector the Ral-binding protein 1 (RalBP1). RalBP1 is involved in endocytosis and in regulating the dynamics of the actin cytoskeleton. It also regulates early development since it is required for the completion of gastrulation in Xenopus laevis. RalBP1 has also been reported to be the main transporter of glutathione electrophiles, and it is involved in multidrug resistance. Such a variety of functions could be explained by a differential regulation of RalBP1 localization. In this study, we have detected endogenous RalBP1 in the nucleus of interphasic cells. This nuclear targeting is mediated by nuclear localization sequences that map to the N-terminal third of the protein. Moreover, in X. laevis embryos, a C-terminal coiled-coil sequence mediates RalBP1 retention in the nucleus. We have also observed RalBP1 at the level of the actin cytoskeleton, a localization that depends on interaction of the protein with active Ral. During mitosis RalBP1 also associates with the mitotic spindle and the centrosome, a localization that could be negatively regulated by active Ral. Finally, we demonstrate the presence of post-transcriptional and post-translational isoforms of RalBP1 lacking the Ral-binding domain, which opens new possibilities for the existence of Ral-independent functions.
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Affiliation(s)
- Jonathan Fillatre
- Mécanismes Moléculaires du Développement, Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité. 15, rue Hélène Brion. 75205 Paris, France
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16
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Abstract
After axotomy of embryonic hippocampal neurons in vitro, some of the axotomized axons lose their identity, and new axons arise and grow. This axotomy-induced axonogenesis requires importin, suggesting that some injury-induced signals are transported via axons to elicit axonogenesis after axotomy. In this study, we show that STAT3 is activated in response to axotomy. Because STAT3 was co-immunoprecipitated with importin β in the axotomized neurons, we suggest that STAT3 is retrogradely transported as molecular cargo of importin α/β heterodimers. Indeed, inhibition of importin α binding with STAT3 resulted in the attenuation of axonogenesis. Silencing STAT3 blocked the axonogenesis, demonstrating that STAT3 is necessary for axotomy-induced axonogenesis. Furthermore, the overexpression of STAT3 enhanced axotomy-induced axonogenesis. Taken together, these results demonstrate that activation and retrograde transport of STAT3 in injured axons have key roles in the axotomy-induced axonogenesis of hippocampal neurons.
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17
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Vogt M, Domoszlai T, Kleshchanok D, Lehmann S, Schmitt A, Poli V, Richtering W, Müller-Newen G. The role of the N-terminal domain in dimerization and nucleocytoplasmic shuttling of latent STAT3. J Cell Sci 2011; 124:900-9. [PMID: 21325026 DOI: 10.1242/jcs.072520] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
STAT3 is an important transcription factor involved in immunity and cancer. In response to cytokine stimulation, STAT3 becomes phosphorylated on a single tyrosine residue. Tyrosine-phosphorylated STAT3 accumulates in the nucleus, binds to specific DNA response elements and induces gene expression. Unphosphorylated, latent STAT3 shuttles constitutively between cytoplasm and nucleus. We analysed the importance of previously identified putative nuclear localization sequences (NLS) and nuclear export sequences (NES) for nucleocytoplasmic shuttling of latent STAT3 using STAT3-deficient cells reconstituted with fluorescently labelled STAT3 mutants. Mutation of a putative NLS or NES sequence did not impair nucleocytoplasmic shuttling of latent STAT3. We were also interested in the structural requirements for dimerization of unphosphorylated STAT3 and its relevance for nucleocytoplasmic shuttling. By native gel electrophoresis and dual-focus fluorescence correlation spectroscopy (2f-FCS) we identified the N-terminal domain (amino acids 1-125) to be essential for formation of unphosphorylated STAT3 dimers but not for assembly of tyrosine-phosphorylated STAT3 dimers. In resting cells, the monomeric N-terminal deletion mutant (STAT3-ΔNT) shuttles faster between the cytoplasm and nucleus than the wild-type STAT3, indicating that dimer formation is not required for nucleocytoplasmic shuttling of latent STAT3. STAT3-ΔNT becomes phosphorylated and dimerizes in response to interleukin-6 stimulation but, surprisingly, does not accumulate in the nucleus. These results highlight the importance of the N-terminal domain in the formation of unphosphorylated STAT3 dimers and nuclear accumulation of STAT3 upon phosphorylation.
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Affiliation(s)
- Michael Vogt
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Pauwelsstrasse 30, Aachen 52074, Germany
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18
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Wagner T, Kraeussling M, Fedorov L, Reiss C, Kneitz B, Schartl M. STAT3 and SMAD1 Signaling in Medaka Embryonic Stem-Like Cells and Blastula Embryos. Stem Cells Dev 2009; 18:151-60. [DOI: 10.1089/scd.2007.0262] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- T.U. Wagner
- University of Wurzburg, Physiological Chemistry I, Wurzburg, Germany
| | - M. Kraeussling
- University of Wurzburg, Physiological Chemistry I, Wurzburg, Germany
| | - L.M. Fedorov
- University of Wurzburg, Physiological Chemistry I, Wurzburg, Germany
| | - C. Reiss
- University of Wurzburg, Physiological Chemistry I, Wurzburg, Germany
| | - B. Kneitz
- Department of Urology and Paediatric Urology, Bavarian Julius Maximilians University Medical School, Wurzburg, Germany
| | - M. Schartl
- University of Wurzburg, Physiological Chemistry I, Wurzburg, Germany
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19
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Huang Y, Qiu J, Dong S, Redell MS, Poli V, Mancini MA, Tweardy DJ. Stat3 isoforms, alpha and beta, demonstrate distinct intracellular dynamics with prolonged nuclear retention of Stat3beta mapping to its unique C-terminal end. J Biol Chem 2007; 282:34958-67. [PMID: 17855361 DOI: 10.1074/jbc.m704548200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Two isoforms of Stat3 (signal transducer and activator of transcription 3) are expressed in cells, alpha (p92) and beta (p83), both derived from a single gene by alternative mRNA splicing. The 55-residue C-terminal transactivation domain of Stat3alpha is deleted in Stat3beta and replaced by seven unique C-terminal residues (CT7) whose function remains uncertain. We subcloned the open reading frames of Stat3alpha and Stat3beta into the C terminus of green fluorescent protein (GFP). Fluorescent microscopic analysis of HEK293T cells transiently transfected with GFP-Stat3alpha or GFP-Stat3beta revealed similar kinetics and cytokine concentration dependence of nuclear accumulation; these findings were confirmed by high throughput microscope analysis of murine embryonic fibroblasts that lacked endogenous Stat3 but stably expressed either GFP-Stat3alpha or GFP-Stat3beta. However, although time to half-maximal cytoplasmic reaccumulation after cytokine withdrawal was 15 min for GFP-Stat3alpha, it was >180 min for GFP-Stat3beta. Furthermore, although the intranuclear mobility of GFP-Stat3alpha was rapid and increased with cytokine stimulation, the intranuclear mobility of GFP-Stat3beta in unstimulated cells was slower than that of GFP-Stat3alpha in unstimulated cells and was slowed further following cytokine stimulation. Deletion of the unique CT7 domain from Stat3beta eliminated prolonged nuclear retention but did not alter its intranuclear mobility. Thus, Stat3alpha and Stat3beta have distinct intracellular dynamics, with Stat3beta exhibiting prolonged nuclear retention and reduced intranuclear mobility especially following ligand stimulation. Prolonged nuclear retention, but not reduced intranuclear mobility, mapped to the CT7 domain of Stat3beta.
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Affiliation(s)
- Ying Huang
- Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, Texas 77030, USA
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20
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Chen W, Khurana Hershey GK. Signal transducer and activator of transcription signals in allergic disease. J Allergy Clin Immunol 2007; 119:529-41; quiz 542-3. [PMID: 17336608 DOI: 10.1016/j.jaci.2007.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 01/03/2007] [Accepted: 01/05/2007] [Indexed: 01/05/2023]
Abstract
Signal transducer and activator of transcription (STAT) proteins are a group of transcription factors that transmit signals from the extracellular milieu of cells to the nucleus. They are crucial for the signaling of many cytokines that are mediators of allergic inflammation and impact various cell types critical to allergy including epithelial cells, mast cells, lymphocytes, dendritic cells, and eosinophils. Dysregulation of STAT signaling has been implicated in allergic disease, highlighting the importance of these ubiquitous molecules in allergic inflammation and the potential of these pathways as a target for therapeutic intervention. This review will summarize the current understanding of the roles of STAT signaling in allergic disease and the potential of targeting STATs for the treatment of allergic disorders, emphasizing recent observations.
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Affiliation(s)
- Weiguo Chen
- Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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