1
|
Liang D, Wang Q, Zhang W, Tang H, Song C, Yan Z, Liang Y, Wang H. JAK/STAT in leukemia: a clinical update. Mol Cancer 2024; 23:25. [PMID: 38273387 PMCID: PMC10811937 DOI: 10.1186/s12943-023-01929-1] [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: 11/01/2023] [Accepted: 12/28/2023] [Indexed: 01/27/2024] Open
Abstract
Over the past three decades, considerable efforts have been expended on understanding the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway in leukemia, following the identification of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs). The aim of this review is to summarize the latest progress in our understanding of the involvement of the JAK/STAT signaling pathway in the development of leukemia. We also attempt to provide insights into the current use of JAK/STAT inhibitors in leukemia therapy and explore pertinent clinical trials in this field.
Collapse
Affiliation(s)
- Dong Liang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Qiaoli Wang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Wenbiao Zhang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Hailin Tang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Cailu Song
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Zhimin Yan
- Department of Hematology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China.
| | - Yang Liang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China.
| | - Hua Wang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, China.
| |
Collapse
|
2
|
Xue C, Yao Q, Gu X, Shi Q, Yuan X, Chu Q, Bao Z, Lu J, Li L. Evolving cognition of the JAK-STAT signaling pathway: autoimmune disorders and cancer. Signal Transduct Target Ther 2023; 8:204. [PMID: 37208335 DOI: 10.1038/s41392-023-01468-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/22/2023] [Indexed: 05/21/2023] Open
Abstract
The Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathway is an evolutionarily conserved mechanism of transmembrane signal transduction that enables cells to communicate with the exterior environment. Various cytokines, interferons, growth factors, and other specific molecules activate JAK-STAT signaling to drive a series of physiological and pathological processes, including proliferation, metabolism, immune response, inflammation, and malignancy. Dysregulated JAK-STAT signaling and related genetic mutations are strongly associated with immune activation and cancer progression. Insights into the structures and functions of the JAK-STAT pathway have led to the development and approval of diverse drugs for the clinical treatment of diseases. Currently, drugs have been developed to mainly target the JAK-STAT pathway and are commonly divided into three subtypes: cytokine or receptor antibodies, JAK inhibitors, and STAT inhibitors. And novel agents also continue to be developed and tested in preclinical and clinical studies. The effectiveness and safety of each kind of drug also warrant further scientific trials before put into being clinical applications. Here, we review the current understanding of the fundamental composition and function of the JAK-STAT signaling pathway. We also discuss advancements in the understanding of JAK-STAT-related pathogenic mechanisms; targeted JAK-STAT therapies for various diseases, especially immune disorders, and cancers; newly developed JAK inhibitors; and current challenges and directions in the field.
Collapse
Affiliation(s)
- Chen Xue
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qinfan Yao
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xinyu Gu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qingmiao Shi
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xin Yuan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qingfei Chu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhengyi Bao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Juan Lu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| |
Collapse
|
3
|
Zhu M, Li S, Cao X, Rashid K, Liu T. The STAT family: Key transcription factors mediating crosstalk between cancer stem cells and tumor immune microenvironment. Semin Cancer Biol 2023; 88:18-31. [PMID: 36410636 DOI: 10.1016/j.semcancer.2022.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022]
Abstract
Signal transducer and activator of transcription (STAT) proteins compose a family of transcription factors critical for cancer stem cells (CSCs), and they are involved in maintaining stemness properties, enhancing cell proliferation, and promoting metastasis. Recent studies suggest that STAT proteins engage in reciprocal communication between CSCs and infiltrate immune cell populations in the tumor microenvironment (TME). Emerging evidence has substantiated the influence of immune cells, including macrophages, myeloid-derived suppressor cells, and T cells, on CSC survival through the regulation of STAT signaling. Conversely, dysregulation of STATs in CSCs or immune cells contributes to the establishment of an immunosuppressive TME. Thus, STAT proteins are promising therapeutic targets for cancer treatment, especially when used in combination with immunotherapy. From this perspective, we discuss the complex roles of STATs in CSCs and highlight their functions in the crosstalk between CSCs and the immune microenvironment. Finally, cutting-edge clinical trial progress with STAT signaling inhibitors is summarized.
Collapse
Affiliation(s)
- Mengxuan Zhu
- Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, China; Center of Evidence-based Medicine, Fudan University, Shanghai, China
| | - Suyao Li
- Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, China; Center of Evidence-based Medicine, Fudan University, Shanghai, China
| | - Xin Cao
- Institute of Clinical Science, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Khalid Rashid
- Department of Cancer Biology, Faculty of Medicine, University of Cincinnati, OH, USA.
| | - Tianshu Liu
- Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, China; Center of Evidence-based Medicine, Fudan University, Shanghai, China.
| |
Collapse
|
4
|
Zhou H, Zhao C, Wang P, Yang W, Zhu H, Zhang S. Regulators involved in trophoblast syncytialization in the placenta of intrauterine growth restriction. Front Endocrinol (Lausanne) 2023; 14:1107182. [PMID: 36798658 PMCID: PMC9927020 DOI: 10.3389/fendo.2023.1107182] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
Placental dysfunction refers to the insufficiency of placental perfusion and chronic hypoxia during early pregnancy, which impairs placental function and causes inadequate supply of oxygen and nutrients to the fetus, affecting fetal development and health. Fetal intrauterine growth restriction, one of the most common outcomes of pregnancy-induced hypertensions, can be caused by placental dysfunction, resulting from deficient trophoblast syncytialization, inadequate trophoblast invasion and impaired vascular remodeling. During placental development, cytotrophoblasts fuse to form a multinucleated syncytia barrier, which supplies oxygen and nutrients to meet the metabolic demands for fetal growth. A reduction in the cell fusion index and the number of nuclei in the syncytiotrophoblast are found in the placentas of pregnancies complicated by IUGR, suggesting that the occurrence of IUGR may be related to inadequate trophoblast syncytialization. During the multiple processes of trophoblasts syncytialization, specific proteins and several signaling pathways are involved in coordinating these events and regulating placental function. In addition, epigenetic modifications, cell metabolism, senescence, and autophagy are also involved. Study findings have indicated several abnormally expressed syncytialization-related proteins and signaling pathways in the placentas of pregnancies complicated by IUGR, suggesting that these elements may play a crucial role in the occurrence of IUGR. In this review, we discuss the regulators of trophoblast syncytialization and their abnormal expression in the placentas of pregnancies complicated by IUGR.
Collapse
Affiliation(s)
- Hanjing Zhou
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Chenqiong Zhao
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Peixin Wang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Weijie Yang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Haiyan Zhu
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
- *Correspondence: Songying Zhang, ; Haiyan Zhu,
| | - Songying Zhang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
- *Correspondence: Songying Zhang, ; Haiyan Zhu,
| |
Collapse
|
5
|
STAT signaling as a target for intervention: from cancer inflammation and angiogenesis to non-coding RNAs modulation. Mol Biol Rep 2022; 49:8987-8999. [PMID: 35474053 DOI: 10.1007/s11033-022-07399-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/10/2022] [Accepted: 03/16/2022] [Indexed: 12/21/2022]
Abstract
As a landmark, scientific investigation in cytokine signaling and interferon-related anti-viral activity, signal transducer and activator of transcription (STAT) family of proteins was first discovered in the 1990s. Today, we know that the STAT family consists of several transcription factors which regulate various molecular and cellular processes, including proliferation, angiogenesis, and differentiation in human carcinoma. STAT family members play an active role in transducing signals from cell membrane to nucleus through intracellular signaling and thus activating gene transcription. Additionally, they are also associated with the development and progression of human cancer by facilitating inflammation, cell survival, and resistance to therapeutic responses. Accumulating evidence suggests that not all STAT proteins are associated with the progression of human malignancy; however, STAT3/5 are constitutively activated in various cancers, including multiple myeloma, lymphoma, breast cancer, prostate hepatocellular carcinoma, and non-small cell lung cancer. The present review highlights how STAT-associated events are implicated in cancer inflammation, angiogenesis and non-coding RNA (ncRNA) modulation to highlight potential intervention into carcinogenesis-related cellular processes.
Collapse
|
6
|
Nguyen HT, Najih M, Martin LJ. The AP-1 family of transcription factors are important regulators of gene expression within Leydig cells. Endocrine 2021; 74:498-507. [PMID: 34599696 DOI: 10.1007/s12020-021-02888-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Members of the AP-1 family of transcription factors are immediate early genes being modulated by different extracellular signals. The aim of this review is to highlight the important roles of AP-1 members in transcriptional regulation of genes important for testicular Leydig cell function and male testosterone production. METHODS A search of the relevant literature was performed in Google Scholar and NCBI Pubmed for AP-1 members and Leydig cells. Additional information was accessed from references of relevant articles. Only primary data from original peer-reviewed articles was considered for this review. RESULTS Different signaling pathways important for Leydig cells' functions are involved in the regulation of the activity of AP-1 members. These transcription factors participate in the regulation of genes related to different biological processes important for Leydig cells. CONCLUSIONS We conclude that members of the AP-1 family of transcription factors play critical roles in the regulation of Leydig cell proliferation, steroidogenesis, and cell-to-cell communication.
Collapse
Affiliation(s)
- Ha Tuyen Nguyen
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Mustapha Najih
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Luc J Martin
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada.
| |
Collapse
|
7
|
Butturini E, Carcereri de Prati A, Mariotto S. Redox Regulation of STAT1 and STAT3 Signaling. Int J Mol Sci 2020; 21:ijms21197034. [PMID: 32987855 PMCID: PMC7582491 DOI: 10.3390/ijms21197034] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 01/07/2023] Open
Abstract
STAT1 and STAT3 are nuclear transcription factors that regulate genes involved in cell cycle, cell survival and immune response. The cross-talk between these signaling pathways determines how cells integrate the environmental signals received ultimately translating them in transcriptional regulation of specific sets of genes. Despite being activated downstream of common cytokine and growth factors, STAT1 and STAT3 play essentially antagonistic roles and the disruption of their balance directs cells from survival to apoptotic cell death or from inflammatory to anti-inflammatory responses. Different mechanisms are proposed to explain this yin-yang relationship. Considering the redox aspect of STATs proteins, this review attempts to summarize the current knowledge of redox regulation of STAT1 and STAT3 signaling focusing the attention on the post-translational modifications that affect their activity.
Collapse
|
8
|
Azrakhsh NA, Mensah-Glanowska P, Sand K, Kittang AO. Targeting Immune Signaling Pathways in Clonal Hematopoiesis. Curr Med Chem 2019; 26:5262-5277. [PMID: 30907306 DOI: 10.2174/0929867326666190325100636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/05/2019] [Accepted: 03/12/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND Myeloid neoplasms are a diverse group of malignant diseases with different entities and numerous patho-clinical features. They arise from mutated clones of hematopoietic stem- and progenitor cells which expand by outperforming their normal counterparts. The intracellular signaling profile of cancer cells is the sum of genetic, epigenetic and microenvironmental influences, and the multiple interconnections between different signaling pathways make pharmacological targeting complicated. OBJECTIVE To present an overview of known somatic mutations in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) and the inflammatory signaling pathways affected by them, as well as current efforts to therapeutically modulate this aberrant inflammatory signaling. METHODS In this review, we extensively reviewed and compiled salient information with ClinicalTrials.gov as our source on ongoing studies, and PubMed as our authentic bibliographic source, using a focused review question. RESULTS Mutations affecting immune signal transduction are present to varying extents in clonal myeloid diseases. While MPN are dominated by a few common mutations, a multitude of different genes can be mutated in MDS and AML. Mutations can also occur in asymptomatic persons, a finding called clonal hematopoiesis of indeterminate potential (CHIP). Mutations in FLT3, JAK, STAT, CBL and RAS can lead to aberrant immune signaling. Protein kinase inhibitors are entering the clinic and are extensively investigated in clinical trials in MPN, MDS and AML. CONCLUSION In summary, this article summarizes recent research on aberrant inflammatory signaling in clonal myeloid diseases and the clinical therapeutic potential of modulation of signal transduction and effector proteins in the affected pathways.
Collapse
Affiliation(s)
| | - Patrycja Mensah-Glanowska
- Department of Hematology, Jagiellonian University Medical College / University Hospital, Krakow, Poland
| | - Kristoffer Sand
- Clinic of Medicine and Rehabilitation, More and Romsdal Hospital Trust, Alesund, Norway
| | - Astrid Olsnes Kittang
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Medicine, Section for Hematology, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
9
|
Travis B, Shaw PLR, Liu B, Ravindra K, Iliff H, Al-Hashimi HM, Schumacher MA. The RRM of the kRNA-editing protein TbRGG2 uses multiple surfaces to bind and remodel RNA. Nucleic Acids Res 2019; 47:2130-2142. [PMID: 30544166 PMCID: PMC6393287 DOI: 10.1093/nar/gky1259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/29/2018] [Accepted: 12/11/2018] [Indexed: 12/12/2022] Open
Abstract
Kinetoplastid RNA (kRNA) editing takes place in the mitochondria of kinetoplastid protists and creates translatable mRNAs by uridine insertion/deletion. Extensively edited (pan-edited) transcripts contain quadruplex forming guanine stretches, which must be remodeled to promote uridine insertion/deletion. Here we show that the RRM domain of the essential kRNA-editing factor TbRGG2 binds poly(G) and poly(U) RNA and can unfold both. A region C-terminal to the RRM mediates TbRGG2 dimerization, enhancing RNA binding. A RRM-U4 RNA structure reveals a unique RNA-binding mechanism in which the two RRMs of the dimer employ aromatic residues outside the canonical RRM RNA-binding motifs to encase and wrench open the RNA, while backbone atoms specify the uridine bases. Notably, poly(G) RNA is bound via a different binding surface. Thus, these data indicate that TbRGG2 RRM can bind and remodel several RNA substrates suggesting how it might play multiple roles in the kRNA editing process.
Collapse
Affiliation(s)
- Brady Travis
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Porsha L R Shaw
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Bei Liu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Krishna Ravindra
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hadley Iliff
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Chemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| |
Collapse
|
10
|
Fujiki R, Hijikata A, Shirai T, Okada S, Kobayashi M, Ohara O. Molecular mechanism and structural basis of gain-of-function of STAT1 caused by pathogenic R274Q mutation. J Biol Chem 2017; 292:6240-6254. [PMID: 28258222 DOI: 10.1074/jbc.m116.753848] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 02/13/2017] [Indexed: 11/06/2022] Open
Abstract
Gain-of-function (GOF) mutations in the STAT1 gene are critical for the onset of chronic mucocutaneous candidiasis (CMC) disease. However, the molecular basis for the gain of STAT1 function remains largely unclear. Here, we investigated the structural features of STAT1 GOF residues to better understand the impact of these pathogenic mutations. We constructed STAT1 alanine mutants of the α3 helix residues of the coiled-coil domain, which are frequently found in CMC pathogenic mutations, and measured their transcriptional activities. Most of the identified GOF residues were located inside the coiled-coil domain stem structure or at the protein surface of the anti-parallel dimer interface. Unlike those, Arg-274 was adjacent to the DNA-binding domain. In addition, Arg-274 was found to functionally interact with Gln-441 in the DNA-binding domain. Because Gln-441 is located at the anti-parallel dimer contact site, Gln-441 reorientation by Arg-274 mutation probably impedes formation of the dimer. Further, the statistical analysis of RNA-seq data with STAT1-deficient epithelial cells and primary T cells from a CMC patient revealed that the R274Q mutation affected gene expression levels of 66 and 76 non-overlapping RefSeq genes, respectively. Because their transcription levels were only slightly modulated by wild-type STAT1, we concluded that the R274Q mutation increased transcriptional activity but did not change dramatically the repertoire of STAT1 targets. Hence, we provide a novel mechanism of STAT1 GOF triggered by a CMC pathogenic mutation.
Collapse
Affiliation(s)
- Ryoji Fujiki
- From the Department of Technology Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu-Shi, Chiba-Ken, 292-0818,
| | - Atsushi Hijikata
- the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama-Shi, Shiga-Ken 526-0829, and
| | - Tsuyoshi Shirai
- the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama-Shi, Shiga-Ken 526-0829, and
| | - Satoshi Okada
- the Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3, Kasumi, Minami-Ku, Hiroshima-Shi, Hiroshima-Ken 734-8551, Japan
| | - Masao Kobayashi
- the Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3, Kasumi, Minami-Ku, Hiroshima-Shi, Hiroshima-Ken 734-8551, Japan
| | - Osamu Ohara
- From the Department of Technology Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu-Shi, Chiba-Ken, 292-0818
| |
Collapse
|
11
|
Siavash H, Nikitakis N, Sauk J. Signal Transducers and Activators of Transcription: Insights into the Molecular Basis of Oral Cancer. ACTA ACUST UNITED AC 2016; 15:298-307. [DOI: 10.1177/154411130401500505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent efforts on developing more direct and effective targets for cancer therapy have revolved around a family of transcription factors known as STATs (signal transducers and activators of transcription). STAT proteins are latent cytoplasmic transcription factors that become activated in response to extracellular signaling proteins. STAT proteins have been convincingly reported to possess oncogenic properties in a plethora of human cancers, including oral and oropharyngeal cancer. Signal transduction pathways mediated by these oncogenic transcription factors and their regulation in oral cancer are the focus of this review.
Collapse
Affiliation(s)
- H. Siavash
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| | - N.G. Nikitakis
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| | - J.J. Sauk
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| |
Collapse
|
12
|
Borg AJ, Yong HEJ, Lappas M, Degrelle SA, Keogh RJ, Da Silva-Costa F, Fournier T, Abumaree M, Keelan JA, Kalionis B, Murthi P. Decreased STAT3 in human idiopathic fetal growth restriction contributes to trophoblast dysfunction. Reproduction 2015; 149:523-32. [PMID: 25713425 DOI: 10.1530/rep-14-0622] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Abnormal trophoblast function is associated with fetal growth restriction (FGR). The JAK-STAT pathway is one of the principal signalling mechanisms by which cytokines and growth factors modulate cell proliferation, differentiation, cell migration and apoptosis. The expression of placental JAK-STAT genes in human idiopathic FGR is unknown. In this study, we propose the hypothesis that JAK-STAT pathway genes are differentially expressed in idiopathic FGR-affected pregnancies and contribute to abnormal feto-placental growth by modulating the expression of the amino acid transporter SNAT2, differentiation marker CGB/human chorionic gonadotrophin beta-subunit (β-hCG) and apoptosis markers caspases 3 and 8, and TP53. Expression profiling of FGR-affected placentae revealed that mRNA levels of STAT3, STAT2 and STAT5B decreased by 69, 52 and 50%, respectively, compared with gestational-age-matched controls. Further validation by real-time PCR and immunoblotting confirmed significantly lower STAT3 mRNA and STAT3 protein (total and phosphorylated) levels in FGR placentae. STAT3 protein was localised to the syncytiotrophoblast (ST) in both FGR and control placentae. ST differentiation was modelled by in vitro differentiation of primary villous trophoblast cells from first-trimester and term placentae, and by treating choriocarcinoma-derived BeWo cells with forskolin in cell culture. Differentiation in these models was associated with increased STAT3 mRNA and protein levels. In BeWo cells treated with siRNA targeting STAT3, the mRNA and protein levels of CGB/β-hCG, caspases 3 and 8, and TP53 were significantly increased, while that of SNAT2 was significantly decreased compared with the negative control siRNA. In conclusion, we report that decreased STAT3 expression in placentae may contribute to abnormal trophoblast function in idiopathic FGR-affected pregnancies.
Collapse
Affiliation(s)
- A J Borg
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - H E J Yong
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - M Lappas
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - S A Degrelle
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesP
| | - R J Keogh
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - F Da Silva-Costa
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - T Fournier
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - M Abumaree
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - J A Keelan
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - B Kalionis
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| | - P Murthi
- Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia Department of Perinatal MedicinePregnancy Research Centre, The Royal Women's Hospital, Parkville, Victoria, AustraliaDepartment of Obstetrics and GynaecologyUniversity of Melbourne, Melbourne, Victoria, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital for Women, Heidelberg, Victoria, AustraliaINSERM-U767Faculté des Sciences Pharmaceutiques et Biologiques, Paris F-75006, FranceUniversite Paris DescartesParis F-75006, FrancePremUp FoundationParis F-75006, FranceCollege of Science and Health ProfessionsKing Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi ArabiaSchool of Women's and Infants' HealthKing Edward Memorial Hospital, University of Western Australia, Subiaco, Western Australia, Australia
| |
Collapse
|
13
|
Dokduang H, Techasen A, Namwat N, Khuntikeo N, Pairojkul C, Murakami Y, Loilome W, Yongvanit P. STATs profiling reveals predominantly-activated STAT3 in cholangiocarcinoma genesis and progression. JOURNAL OF HEPATO-BILIARY-PANCREATIC SCIENCES 2014; 21:767-76. [PMID: 25044480 DOI: 10.1002/jhbp.131] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND We investigated the aberrant expression of the STAT family in humans and liver fluke (Opisthorchis viverrini, Ov)-induced hamster cholangiocarcinoma (CCA) tissues. METHODS The expression and phosphorylation of STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b and STAT6 in human hamster CCA tissues were immunohistochemistry-profiled. Localizations of STAT5 in macrophages and lipopolysaccharide (LPS)-induced macrophage-conditioned media mediated STAT3 activation in CCA cells were demonstrated. RESULTS The expressions of STAT 1-4 and 6 were detected in the cytoplasm of hyperplastic bile ducts and tumor cells, whereas STAT5a and STAT5b were observed in macrophages and connective tissues surrounding tumor, respectively. The expressions of STAT3 and STAT5b were significantly observed in tumors with a poorer histological differentiation. STAT3 expression was significantly associated with shorter survival of CCA patients and was predominately activated in CCA cell lines. In the CCA-hamsters, STATs expression was gradually increased along the carcinogenesis, especially at 30 days post-infection in which the inflammatory response was markedly observed, showing the correlation between the inflammation and STATs activation. Moreover, LPS-induced macrophage-conditioned media could mediate STAT3 activation in CCA cells. CONCLUSIONS STAT3 is the major STAT, which plays roles in the inflammation that contributes to CCA carcinogenesis and progression and may serve as a marker for a poor prognosis of CCA.
Collapse
Affiliation(s)
- Hasaya Dokduang
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Liver injury is a complicated pathological process caused by multiple biological and chemical factors. The repair mechanism after liver injury is the focus of liver research, involving numerous signaling pathways, cytokines and transcription factors. Signal transducer and activator of transcription 3 (STAT3) is a cytoplasmic signal transcription factor which belongs to the signal transducers and activators of transcription family and plays a critical role in the process of liver injury repair. STAT3 activation boosts the process of liver repair by promoting hepatocyte proliferation, maintains homeostasis by regulating metabolism of carbohydrates and lipids, and prevents the liver from bacterial infection and acute liver injury induced by toxic chemicals and drugs by increasing the expression of beneficial acute phase proteins. This review focuses on the composition of STAT3 signaling pathway and its role in liver injury repair.
Collapse
|
15
|
Samsonov A, Zenser N, Zhang F, Zhang H, Fetter J, Malkov D. Tagging of genomic STAT3 and STAT1 with fluorescent proteins and insertion of a luciferase reporter in the cyclin D1 gene provides a modified A549 cell line to screen for selective STAT3 inhibitors. PLoS One 2013; 8:e68391. [PMID: 23950841 PMCID: PMC3732202 DOI: 10.1371/journal.pone.0068391] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/29/2013] [Indexed: 01/05/2023] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) is an oncogenic protein that is constitutively activated in numerous cancer cell lines and human cancers. Another STAT family member, STAT1, possesses cancer-inhibitory properties and can promote apoptosis in tumor cells upon activation. To better characterize these important cancer related genes, we tagged STAT3 and STAT1 loci with fluorescent protein (FP) sequences (RFP and GFP respectively) by targeted integration via zinc finger nuclease (ZFN)--mediated homologous recombination in A549 cells that express aberrantly activated STAT3. We inserted the FP transgenes at the N-terminus of the STAT3 locus and at the C-terminus of the STAT1 locus. The integration resulted in endogenous expression of fluorescent STAT3 and STAT1 chimeric fusion proteins. When stimulated with IL-6 or IFN-γ, the cells showed robust nuclear translocation of RFP-STAT3 or STAT1-GFP, respectively. Pre-incubation of cells with a known specific STAT3 inhibitor showed that IFN-γ-induced translocation of STAT1-GFP was not impaired. STAT3 activates multiple downstream targets such as genes involved in cell cycle progression - e.g. cyclin D1. To detect changes in expression of endogenous cyclin D1, we used ZFN technology to insert a secreted luciferase reporter behind the cyclin D1 promoter and separated the luciferase and cyclin D1 coding regions by a 2A sequence to induce a translational skip. The luciferase insertion was made in the RFP-STAT3/STAT1-GFP cell line to have all three reporters in a single cell line. Addition of a STAT3 inhibitor led to suppression of cyclin D1 promoter activity and cell growth arrest. The triple-modified cell line provides a simple and convenient method for high-content screening and pre-clinical testing of potential STAT3 inhibitors in live cells while ensuring that the STAT1 pathway is not affected. This approach of reporting endogenous gene activities using ZFN technology could be applied to other cancer targets.
Collapse
Affiliation(s)
- Andrey Samsonov
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| | - Nathan Zenser
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| | - Fan Zhang
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| | - Hongyi Zhang
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| | - John Fetter
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| | - Dmitry Malkov
- Cell-Based Assays/Reporter Cell Lines, Sigma-Aldrich, St. Louis, Missouri, United States of America
| |
Collapse
|
16
|
Bonham AJ, Wenta N, Osslund LM, Prussin AJ, Vinkemeier U, Reich NO. STAT1:DNA sequence-dependent binding modulation by phosphorylation, protein:protein interactions and small-molecule inhibition. Nucleic Acids Res 2012. [PMID: 23180800 PMCID: PMC3553987 DOI: 10.1093/nar/gks1085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The DNA-binding specificity and affinity of the dimeric human transcription factor (TF) STAT1, were assessed by total internal reflectance fluorescence protein-binding microarrays (TIRF-PBM) to evaluate the effects of protein phosphorylation, higher-order polymerization and small-molecule inhibition. Active, phosphorylated STAT1 showed binding preferences consistent with prior characterization, whereas unphosphorylated STAT1 showed a weak-binding preference for one-half of the GAS consensus site, consistent with recent models of STAT1 structure and function in response to phosphorylation. This altered-binding preference was further tested by use of the inhibitor LLL3, which we show to disrupt STAT1 binding in a sequence-dependent fashion. To determine if this sequence-dependence is specific to STAT1 and not a general feature of human TF biology, the TF Myc/Max was analysed and tested with the inhibitor Mycro3. Myc/Max inhibition by Mycro3 is sequence independent, suggesting that the sequence-dependent inhibition of STAT1 may be specific to this system and a useful target for future inhibitor design.
Collapse
Affiliation(s)
- Andrew J Bonham
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | | | | | | | | | | |
Collapse
|
17
|
Kaucher AV, Oatley MJ, Oatley JM. NEUROG3 is a critical downstream effector for STAT3-regulated differentiation of mammalian stem and progenitor spermatogonia. Biol Reprod 2012; 86:164, 1-11. [PMID: 22378757 DOI: 10.1095/biolreprod.111.097386] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Spermatogenesis relies on coordinated differentiation of stem and progenitor spermatogonia, and the transcription factor STAT3 is essential for this process in mammals. Here we studied the THY1+ spermatogonial population in mouse testes, which contains spermatogonial stem cells (SSC) and non-stem cell progenitor spermatogonia, to further define the downstream mechanism regulating differentiation. Transcript abundance for the bHLH transcription factor Neurog3 was found to be significantly reduced upon transient inhibition of STAT3 signaling in these cells and exposure to GDNF, a key growth factor regulating self-renewal of SSCs, suppressed activation of STAT3 and in accordance Neurog3 gene expression. Moreover, STAT3 was found to bind the distal Neurog3 promoter/enhancer region in THY1+ spermatogonia and regulate transcription. Transient inhibition of Neurog3 expression in cultures of proliferating THY1+ spermatogonia increased stem cell content after several self-renewal cycles without effecting overall proliferation of the cells, indicating impaired differentiation of SSCs to produce progenitor spermatogonia. Furthermore, cultured THY1+ spermatogonia with induced deficiency of Neurog3 were found to be incapable of differentiation in vivo following transplantation into testes of recipient mice. Collectively, these results establish a mechanism by which activation of STAT3 regulates the expression of NEUROG3 to subsequently drive differentiation of SSC and progenitor spermatogonia in the mammalian germline.
Collapse
Affiliation(s)
- Amy V Kaucher
- Center for Reproductive Biology, School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | | | | |
Collapse
|
18
|
Das S, Shetty P, Valapala M, Dasgupta S, Gryczynski Z, Vishwanatha JK. Signal transducer and activator of transcription 6 (STAT6) is a novel interactor of annexin A2 in prostate cancer cells. Biochemistry 2010; 49:2216-26. [PMID: 20121258 DOI: 10.1021/bi9013038] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Annexin A2 (AnxA2) is a multifunctional Ca(2+)-dependent phospholipid-binding protein, and its overexpression is implicated in malignant transformation of several cancers. In prostate cancer, however, the expression of AnxA2 is lost in prostate intraepithelial neoplasia and reappears in the high-grade tumors, suggesting a complex regulation of AnxA2 in the prostate microenvironment. Since a majority of the biological functions of AnxA2 are mediated by its interaction with other proteins, we performed a yeast two-hybrid assay to search for novel interactors of AnxA2. Our studies revealed that signal transducer and activator of transcription 6 (STAT6), a member of the STAT family of transcription factors, is a binding partner of AnxA2. We confirmed AnxA2-STAT6 interaction by in vitro co-immunoprecipitation and fluorescence resonance energy transfer (FRET) studies and demonstrated that AnxA2 interacts with phosphorylated STAT6. Furthermore, chromatin immunoprecipitation (ChIP) assay revealed that AnxA2 is associated with the STAT6 DNA-binding complex, and luciferase reporter assays demonstrated that AnxA2 upregulates the activity of STAT6. Upon interleukin-4 treatment, AnxA2 stabilizes the cytosolic levels of phosphorylated STAT6 and promotes its nuclear entry. These findings suggest that AnxA2-STAT6 interactions could have potential implications in prostate cancer progression. This report is the first to demonstrate the interaction of AnxA2 with STAT6 and suggests a possible mechanism by which AnxA2 contributes to the metastatic processes of prostate cancer.
Collapse
Affiliation(s)
- Susobhan Das
- Department of Molecular Biology and Immunology and Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA
| | | | | | | | | | | |
Collapse
|
19
|
Watanabe Y, Ikegawa M, Naruse Y, Tanaka M. A novel splicing variant form suppresses the activity of full-length signal transducer and activator of transcription 5A. FEBS J 2009; 276:6312-23. [PMID: 19788420 DOI: 10.1111/j.1742-4658.2009.07339.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Signal transducers and activators of transcription (STATs) regulate a variety of cellular functions, including differentiation and proliferation. STAT3 and STAT5 are known to play important roles in brain processes, such as energy homeostasis and neuronal development. We isolated a novel splicing variant of STAT5A from a cDNA library of the mouse brainstem. This variant, STAT5A_DeltaE18, lacked exon 18 and caused a frameshift in the C-terminus, resulting in deletion of a tyrosine phosphorylation site and a transactivation domain. Although the frameshift region had no characteristic motifs, it was highly serine/threonine-rich and contained a short proline-rich sequence. Expression of STAT5A_DeltaE18 was detected in the mouse brainstem, lung and thymus, but not in the mouse cerebrum or cerebellum. We developed a specific antibody against STAT5A_DeltaE18 and investigated the intracellular localization of this variant. STAT5A_DeltaE18 showed dot-like structures in the cytoplasm and could not translocate into the nucleus after prolactin treatment. STAT5A_DeltaE18 showed a strong tendency to aggregate, which led to coaggregation with STAT5A_full-length. This coaggregation inhibited the nuclear transport of STAT5A and suppressed prolactin-induced activation of STAT5A.
Collapse
Affiliation(s)
- Yoshihisa Watanabe
- Department of Cell Biology, Research Institute for Neurological Diseases and Geriatrics, Kyoto Prefectural University of Medicine, Japan
| | | | | | | |
Collapse
|
20
|
Clarke D, Damera G, Sukkar MB, Tliba O. Transcriptional regulation of cytokine function in airway smooth muscle cells. Pulm Pharmacol Ther 2009; 22:436-45. [PMID: 19393330 DOI: 10.1016/j.pupt.2009.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 01/28/2009] [Accepted: 04/14/2009] [Indexed: 01/01/2023]
Abstract
The immuno-modulatory properties of airway smooth muscle have become of increasing importance in our understanding of the mechanisms underlying chronic inflammation and structural remodeling of the airway wall in asthma and chronic obstructive pulmonary disease (COPD). ASM cells respond to many cytokines, growth factors and lipid mediators to produce a wide array of immuno-modulatory molecules which may in turn orchestrate and perpetuate the disease process in asthma and COPD. Despite numerous studies of the cellular effects of cytokines on cultured ASM, few have identified intracellular signaling pathways by which cytokines modulate or induce these cellular responses. In this review we provide an overview of the transcriptional mechanisms as well as intracellular signaling pathways regulating cytokine functions in ASM cells. The recent discovery of toll-like receptors in ASM cells represents a significant development in our understanding of the immuno-modulatory capabilities of ASM cells. Thus, we also review emerging evidence of the inflammatory response to toll-like receptor activation in ASM cells.
Collapse
Affiliation(s)
- Deborah Clarke
- Respiratory Pharmacology, National Heart & Lung Institute, Imperial College London, London, UK
| | | | | | | |
Collapse
|
21
|
Poritz LS, Zhang WJ, Thompson J, Boyer M, Clark C, Koltun WA. Impaired IL-4 phosphorylation of STAT6 in EBV transformed B-cells. J Surg Res 2009; 162:290-8. [PMID: 19540524 DOI: 10.1016/j.jss.2009.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 12/16/2008] [Accepted: 01/06/2009] [Indexed: 10/21/2022]
Abstract
BACKGROUND The Interleukin-4 signal transducer and activator of transcription 6 (IL-4-STAT6) signaling pathway plays a pivotal role in regulation of gene transcription. We have previously identified a defective STAT6 activational phenotype in response to IL-4 in patients from our familial Inflammatory Bowel Disease registry. This has been termed Stat6(null) and Stat6(high) is the normal phenotype. The purpose of this study was to investigate the defect in Stat6 activation in Stat6(null) cells. METHODS Stat6(null) and Stat6(high) Epstein Barr virus transformed cell lines were stimulated with 10 ng/mL of IL-4 for 0, 10, 30, or 60 min and cytoplasmic and nuclear proteins harvested. Western blot for STAT6, phosphorylated STAT6 (pSTAT6), Janus Kinase (Jak)1 and Jak3 was performed. Cells were also cultured for 48 h and interferon gamma (IFNgamma) measured in the supernatant. Additional cells were cultured with 20 ng/mL of IFNgamma for 90 min or 5 ug of antibody to IFNgamma for 48 h, and then stimulated with IL-4. RESULTS There were no differences in cytoplasmic STAT6 in Stat6(null)versus Stat6(high) cells. In Stat6(high) cells, STAT6 was rapidly phosphorylated and translocated to the nucleus. In Stat6(null) cells there was minimal phosphorylation and translocation of pSTAT6 to the nucleus. Spontaneous secretion of IFNgamma by Stat6(null) cells was significantly higher than Stat6(null) cells. Addition of IFNgamma decreased pSTAT6 in Stat6(high) cells to Stat6(null) levels while blocking IFNgamma increased baseline pSTAT6 in Stat6(null) cells to levels similar to Stat6(high) cells. CONCLUSION This suggests that the spontaneously produced IFNgamma in the Stat6(null) cell lines suppresses STAT6 function and creates the Stat6(null) phenotype.
Collapse
Affiliation(s)
- Lisa S Poritz
- Department of Surgery, The Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, Pennsylvania 17033, USA.
| | | | | | | | | | | |
Collapse
|
22
|
Grattan DR, Steyn FJ, Kokay IC, Anderson GM, Bunn SJ. Pregnancy-induced adaptation in the neuroendocrine control of prolactin secretion. J Neuroendocrinol 2008; 20:497-507. [PMID: 18266946 DOI: 10.1111/j.1365-2826.2008.01661.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During pregnancy, neuroendocrine control of prolactin secretion is markedly altered to allow a state of hyperprolactinaemia to develop. Prolactin secretion is normally tightly regulated by a short-loop negative-feedback mechanism, whereby prolactin stimulates activity of tuberoinfundibular dopamine (TIDA) neurones to increase dopamine secretion into the pituitary portal blood. Dopamine inhibits prolactin secretion, thus reducing prolactin concentrations in the circulation back to the normal low level. Activation of this feedback secretion by placental lactogen during pregnancy maintains relatively low levels of prolactin secretion during early and mid-pregnancy. Despite the continued presence of placental lactogen, however, dopamine secretion from TIDA neurones is reduced during late pregnancy. Moreover, the neurones become completely unresponsive to endogenous or exogenous prolactin at this time, allowing a large nocturnal surge of prolactin to occur from the maternal pituitary gland during the night before parturition. In this review, we describe the changing patterns of prolactin secretion during pregnancy in the rat, and discuss the neuroendocrine mechanisms controlling these changes. The loss of response to prolactin is an important maternal adaptation to pregnancy, allowing the prolonged period of hyperprolactinaemia required for mammary gland development and function and for maternal behaviour immediately after parturition, and possibly also contributing to a range of other adaptive responses in the mother.
Collapse
Affiliation(s)
- David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
| | | | | | | | | |
Collapse
|
23
|
Airway smooth muscle cell as an inflammatory cell: lessons learned from interferon signaling pathways. Ann Am Thorac Soc 2008; 5:106-12. [PMID: 18094092 DOI: 10.1513/pats.200705-060vs] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The present article will describe the potential role of airway smooth muscle (ASM) in mediating both deleterious/beneficial effects of interferons (IFNs) in asthma. First described as beneficial in treating the main features of asthma, the interplay between IFNs and ASM could explain their deleterious actions recently described in a number of different studies. Through multiple mechanisms, including the suppression of steroid action, the synergistic pro-inflammatory actions when combined with other cytokines, and the modulation of calcium metabolism, IFNs are now seen as critical mediators in the pathogenesis of asthma.
Collapse
|
24
|
Marchi B, Burlando B, Panfoli I, Dondero F, Viarengo A, Gallo G. Heavy metal interference with growth hormone signalling in trout hepatoma cells RTH-149. Biometals 2005; 18:179-90. [PMID: 15954744 DOI: 10.1007/s10534-004-6254-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have studied the effects of heavy metals (Hg2+, Cu2+, Cd2+) on growth hormone (GH) activation of tyrosine kinase and Ca2+ signaling in the trout (Oncorhynchus mykiss) hepatoma cell line RTH-149. Molecular cloning techniques using primer designed on Oncorhynchus spp. growth hormone receptor (GHR) genes allowed to isolate a highly homologous cDNA fragment from RTH-149 mRNA. Thereafter, cells were analysed by Western blotting or, alternatively, with Ca2+ imaging using fura-2/AM. Exposure of cells to ovine GH alone produced a stimulation of the JAK2/STAT5 pathway and intracellular free Ca2+ variations similar to what has been observed in mammalian models. Cell pre-exposure to Cu2+, Hg2+ or Cd2+ affected cell response to GH by enhancing (Cu2+) or inhibiting (Cd2+) the phosphorylation of JAK2 and STAT5. Heavy metals induced the activation of the MAP kinase p38, and pre-exposure to Hg2+ or Cu2+ followed by GH enhanced the effect of metal alone. Image analysis of fura2-loaded cells indicated that pre-treatment with Hg2+ prior to GH produced a considerable increase of the [Ca2+]i variation produced by either element, while using Cu2+ or Cd2+ the result was similar but much weaker. Data suggest that heavy metals interfere with GH as follows: Hg2+ is nearly ineffective on JAK/STAT and strongly synergistic on Ca2+ signaling; Cu2+ is activatory on JAK/STAT and slightly activatory on Ca2+; Cd2+ is strongly inhibitory on JAK/STAT and slightly activatory on Ca2+; heavy metals could partially activate STAT via p38 independently from GH interaction.
Collapse
Affiliation(s)
- Barbara Marchi
- Dipartimento di Biologia, Università di Genova, Viale Benedetto XV 5, 16132, Genova, Italy.
| | | | | | | | | | | |
Collapse
|
25
|
Caraglia M, Marra M, Pelaia G, Maselli R, Caputi M, Marsico SA, Abbruzzese A. Alpha-interferon and its effects on signal transduction pathways. J Cell Physiol 2005; 202:323-35. [PMID: 15389589 DOI: 10.1002/jcp.20137] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Interferon-alpha (IFNalpha) is a recombinant protein widely used in the therapy of several neoplasms such as myeloma, renal cell carcinoma, epidermoid cervical and head and neck tumors, and melanoma. IFNalpha, the first cytokine to be produced by recombinant DNA technology, has emerged as an important regulator of cancer cell growth and differentiation, affecting cellular communication and signal transduction pathways. However, the way by which tumor cell growth is directly suppressed by IFNalpha is not well known. Wide evidence exists on the possibility that cancer cells undergo apoptosis after the exposure to the cytokine. Here we will review the consolidate signal transducer and activator of transcription (STAT)-dependent mechanism of action of IFNalpha. We will discuss data obtained by us and others on the triggering of the stress-dependent kinase pathway induced by IFNalpha and its correlations with the apoptotic process. The regulation of the expression of proteins involved in apoptosis occurrence will be also described. In this regard, IFNalpha is emerging as a post-translational controller of the intracellular levels of the apoptosis-related protein tissue transglutaminase (tTG). This new way of regulation of tTG occurs through the modulation of their proteasome-dependent degradation induced by the cytokine. Until today, inconsistent data have been obtained regarding the clinical effectiveness of IFNalpha in the therapy of solid tumors. In fact, the benefit of IFNalpha treatment is limited to some neoplasms while others are completely or partially resistant. The mechanisms of tumor resistance to IFNalpha have been studied in vitro. The alteration of JAK-STAT components of the IFNalpha-induced signaling, can be indeed a mechanism of resistance to IFN. However, we have recently described a reactive mechanism of protection of tumor cells from the apoptosis induced by IFNalpha dependent on the epidermal growth factor (EGF)-mediated Ras/extracellular signal regulated kinase (Erk) signaling. The involvement of the Ras-->Erk pathway in the protection of tumor cells from the apoptosis induced by IFNalpha is further demonstrated by both Ras inactivation by RASN17 transfection and mitogen extracellular signal regulated kinase 1 (Mek-1) inhibition by exposure to PD098059. These data strongly suggest that the specific disruption of the latter could be a useful approach to potentiate the antitumour activity of IFNalpha against human tumors based on the new mechanistic insights achieved in the last years.
Collapse
Affiliation(s)
- Michele Caraglia
- Department of Biochemistry and Biophysics, Second University of Naples, Via Costantinopoli, Naples, Italy.
| | | | | | | | | | | | | |
Collapse
|
26
|
Gallagher KL, Paquette AJ, Nakajima K, Benfey PN. Mechanisms regulating SHORT-ROOT intercellular movement. Curr Biol 2005; 14:1847-51. [PMID: 15498493 DOI: 10.1016/j.cub.2004.09.081] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2004] [Revised: 08/25/2004] [Accepted: 08/25/2004] [Indexed: 11/26/2022]
Abstract
Signaling centers within developing organs regulate morphogenesis in both plants and animals. The putative transcription factor SHORT-ROOT (SHR) is an organizing signal regulating the division of specific stem cells in the Arabidopsis root. Comparison of gene transcription with protein localization indicates that SHR moves in a highly specific manner from the cells of the stele in which it is synthesized outward. Here, we provide evidence that SHR intercellular trafficking is both regulated and targeted. First, we show that subcellular localization of SHR in the stele is intrinsic to the SHR protein. Next, we show that SHR must be present in the cytoplasm to move, providing evidence that SHR movement is regulated. Finally, we describe an informative new shr allele, in which the protein is present in the cytoplasm yet does not move. Thus, in contrast to proteins that move by a process resembling diffusion, a cytoplasmic pool of SHR is not sufficient for movement.
Collapse
|
27
|
Liu T, Jin H, Ullenbruch M, Hu B, Hashimoto N, Moore B, McKenzie A, Lukacs NW, Phan SH. Regulation of found in inflammatory zone 1 expression in bleomycin-induced lung fibrosis: role of IL-4/IL-13 and mediation via STAT-6. THE JOURNAL OF IMMUNOLOGY 2004; 173:3425-31. [PMID: 15322207 DOI: 10.4049/jimmunol.173.5.3425] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Found in inflammatory zone (FIZZ)1, also known as resistin-like molecule alpha, belongs to a novel class of cysteine-rich secreted protein family, named FIZZ/resistin-like molecule, with unique tissue expression patterns. FIZZ1 is induced in alveolar type II epithelial cells (AECs) in bleomycin (BLM)-induced lung fibrosis, and found to induce myofibroblast differentiation in vitro. The objective of this study was to elucidate the regulation of AEC FIZZ1 expression in pulmonary fibrosis. AECs were isolated from rat lungs and the effects of a number of cytokines on FIZZ1 expression were evaluated by RT-PCR. Of all cytokines examined, only IL-4 and IL-13 were effective in stimulating FIZZ1 expression in AECs. Stimulation by IL-4/IL-13 was accompanied by increases in phosphorylated STAT6 and JAK1. FIZZ1 expression was also stimulated by transfection with a STAT6 expression plasmid, but was inhibited by antisense oligonucleotides directed against STAT6. In vivo studies showed that compared with wild-type controls, both IL-4- and IL-13-deficient mice showed reduced BLM-induced lung FIZZ1 expression and fibrosis, which were essentially abolished in IL-4 and IL-13 doubly deficient mice. Furthermore, STAT6-deficient mice showed marked reduction in BLM-induced lung FIZZ1 expression. Thus, IL-4 and IL-13 are potent inducers of AEC FIZZ1 expression via STAT6 and play key roles in BLM-induced lung FIZZ1 expression and fibrosis. This represents a potential mechanism by which IL-4/IL-13 could play a role in the pathogenesis of lung fibrosis.
Collapse
Affiliation(s)
- Tianju Liu
- Department of Pathology, University of Michigan Medical School, Ann Arbor 48109, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Howarth PH, Knox AJ, Amrani Y, Tliba O, Panettieri RA, Johnson M. Synthetic responses in airway smooth muscle. J Allergy Clin Immunol 2004; 114:S32-50. [PMID: 15309017 DOI: 10.1016/j.jaci.2004.04.041] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Human airway smooth muscle (ASM) has several properties and functions that contribute to asthma pathogenesis, and increasing attention is being paid to its synthetic capabilities. ASM can promote the formation of the interstitial extracellular matrix, and in this respect, ASM from asthmatic subjects compared with normal subjects responds differently, both qualitatively and quantitatively. Thus, ASM cells are important regulating cells that potentially contribute to the known alterations within the extracellular matrix in asthma. In addition, through integrin-directed signaling, extracellular matrix components can alter the proliferative, survival, and cytoskeletal synthetic function of ASM cells. ASM also functions as a rich source of biologically active chemokines and cytokines that are capable of perpetuating airway inflammation in asthma and chronic obstructive pulmonary disease by promoting recruitment, activation, and trafficking of inflammatory cells in the airway milieu. Emerging evidence shows that airway remodeling may also be a result of the autocrine action of secreted inflammatory mediators, including T(H)2 cytokines, growth factors, and COX-2-dependent prostanoids. Finally, ASM cells contain both beta(2)-adrenergic receptors and glucocorticoid receptors and may represent a key target for beta(2)-adrenergic receptor agonist/corticosteroid interactions. Combinations of long-acting beta(2)-agonists and corticosteroids appear to have additive and/or synergistic effects in inhibiting inflammatory mediator release and the migration and proliferation of ASM cells.
Collapse
Affiliation(s)
- Peter H Howarth
- Respiratory Cell and Molecular Biology, Southampton General Hospital, Southampton, United Kingdom.
| | | | | | | | | | | |
Collapse
|
29
|
Chen W, Daines MO, Hershey GKK. Methylation of STAT6 modulates STAT6 phosphorylation, nuclear translocation, and DNA-binding activity. THE JOURNAL OF IMMUNOLOGY 2004; 172:6744-50. [PMID: 15153491 DOI: 10.4049/jimmunol.172.11.6744] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Signal transducer and activator of transcription 6 is a transcription factor important for the development of Th2 cells and regulation of gene expression by IL-4 and IL-13. It has been reported that STAT1 activity is regulated by methylation of a conserved arginine residue in the N-terminal domain. Methylation of STAT6 has not yet been explored. We observed methylation of STAT6 in cells transfected with wild-type STAT6, but not in cells transfected with Arg(27)Ala mutant, confirming that STAT6 is methylated on Arg(27). Transfectants expressing mutant Arg(27)Ala STAT6 displayed markedly diminished IL-4-dependent STAT6 phosphorylation and nuclear translocation, and no STAT6 DNA-binding activity compared with wild-type STAT6 transfectants. To confirm this, the experiments were repeated using inhibitors of methylation. In the presence of methylation inhibitors, STAT6 methylation was diminished, as was phosphorylation of STAT6 and STAT6 DNA-binding activity. Thus, methylation is a critical regulator of STAT6 activity, necessary for optimal STAT6 phosphorylation, nuclear translocation, and DNA-binding activity. Furthermore, methylation of STAT6 has distinct effects from those reported with STAT1.
Collapse
Affiliation(s)
- Weiguo Chen
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital, Medical Center, Cincinnati, OH 45229, USA
| | | | | |
Collapse
|
30
|
Razeto A, Ramakrishnan V, Litterst CM, Giller K, Griesinger C, Carlomagno T, Lakomek N, Heimburg T, Lodrini M, Pfitzner E, Becker S. Structure of the NCoA-1/SRC-1 PAS-B domain bound to the LXXLL motif of the STAT6 transactivation domain. J Mol Biol 2004; 336:319-29. [PMID: 14757047 DOI: 10.1016/j.jmb.2003.12.057] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Signal transducer and activator of transcription 6 (STAT6) regulates transcriptional activation in response to interleukin-4 (IL-4) by direct interaction with coactivators. The CREB-binding protein (p300/CBP) and the nuclear coactivator 1 (NCoA-1), a member of the p160/steroid receptor coactivator family, bind independently to specific regions of the STAT6 transactivation domain and act as coactivators. The interaction between STAT6 and NCoA-1 is mediated by an LXXLL motif in the transactivation domain of STAT6. To define the mechanism of coactivator recognition, we determined the crystal structure of the NCoA-1 PAS-B domain in complex with the STAT6 LXXLL motif. The amphipathic, alpha-helical STAT6 LXXLL motif binds mostly through specific hydrophobic interactions to NCoA-1. A single amino acid of the NCoA-1 PAS-B domain establishes hydrophilic interactions with the STAT6 peptide. STAT6 interacts only with the PAS-B domain of NCoA-1 but not with the homologous regions of NCoA-2 and NCoA-3. The residues involved in binding the STAT6 peptide are strongly conserved between the different NCoA family members. Therefore surface complementarity between the hydrophobic faces of the STAT6 fragment and of the NCoA-1 PAS-B domain almost exclusively defines the binding specificity between the two proteins.
Collapse
Affiliation(s)
- Adelia Razeto
- Department for NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Davoodi-Semiromi A, Laloraya M, Kumar GP, Purohit S, Jha RK, She JX. A mutant Stat5b with weaker DNA binding affinity defines a key defective pathway in nonobese diabetic mice. J Biol Chem 2003; 279:11553-61. [PMID: 14701862 DOI: 10.1074/jbc.m312110200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A number of cytokines that finely regulate immune response have been implicated in the pathogenesis or protection of type 1 diabetes and other autoimmune diseases. It is, therefore, of pivotal importance to examine a family of proteins that serve as signal transducers and activators of transcription (STATs), which regulate the transcription of a variety of cytokines. We report here a defective gene (Stat5b) located on chromosome 11 within a previously mapped T1D susceptibility interval (Idd4) in the nonobese diabetic (NOD) mice. Our sequencing analysis revealed a unique mutation C1462A that results in a leucine to methionine (L327M) in Stat5b of NOD mice. Leu(327), the first residue in the DNA binding domain of STAT proteins, is conserved in all identified mammalian STAT proteins. Homology modeling predicted that the mutant Stat5b has a weaker DNA binding, which was confirmed by DNA-protein binding assays. The inapt transcriptional regulation ability of the mutated Stat5b is proved by decreased levels of RNA of Stat5b-regulated genes (IL-2Rbeta and Pim1). Consequently, IL-2Rbeta and Pim1 proteins were shown by Western blotting to have lower levels in NOD compared with normal B6 mice. These proteins have been implicated in immune regulation, apoptosis, activation-induced cell death, and control of autoimmunity. Therefore, the Stat5b pathway is a key molecular defect in NOD mice.
Collapse
Affiliation(s)
- Abdoreza Davoodi-Semiromi
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | | | | | | | | | | |
Collapse
|
32
|
Halayko AJ, Amrani Y. Mechanisms of inflammation-mediated airway smooth muscle plasticity and airways remodeling in asthma. Respir Physiol Neurobiol 2003; 137:209-22. [PMID: 14516727 DOI: 10.1016/s1569-9048(03)00148-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent evidence points to progressive structural change in the airway wall, driven by chronic local inflammation, as a fundamental component for development of irreversible airway hyperresponsiveness. Acute and chronic inflammation is orchestrated by cytokines from recruited inflammatory cells, airway myofibroblasts and myocytes. Airway myocytes exhibit functional plasticity in their capacity for contraction, proliferation, and synthesis of matrix protein and cytokines. This confers a principal role in driving different components of the airway remodeling process, and mediating constrictor hyperresponsiveness. Functional plasticity of airway smooth muscle (ASM) is regulated by an array of environmental cues, including cytokines, which mediate their effects through receptors and a number of intracellular signaling pathways. Despite numerous studies of the cellular effects of cytokines on cultured airway myocytes, few have identified how intracellular signaling pathways modulate or induce these cellular responses. This review summarizes current understanding of these concepts and presents a model for the effects of inflammatory mediators on functional plasticity of ASM in asthma.
Collapse
Affiliation(s)
- Andrew J Halayko
- Departments of Physiology, Internal Medicine, and Pediatrics and Child Health, University of Manitoba, Manitoba, Canada.
| | | |
Collapse
|
33
|
Daines MO, Andrews RP, Chen W, El-Zayaty SA, Hershey GKK. DNA binding activity of cytoplasmic phosphorylated Stat6 is masked by an interaction with a detergent-sensitive factor. J Biol Chem 2003; 278:30971-4. [PMID: 12777374 DOI: 10.1074/jbc.m301094200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription (Stat) 6 is vital to interleukin (IL)-4 and IL-13 responses and the generation of Th2 immunity. We investigated the cellular location of phosphorylated Stat6 and Stat6 DNA binding activity in A201.1 murine B cells and primary splenocytes. Phosphorylated Stat6 was present in cytoplasmic and nuclear extracts from IL-4-treated cells. Confocal microscopy confirmed the presence of phosphorylated Stat6 in the cytoplasm of IL-4-treated cells. In contrast, Stat6 DNA binding activity was present in nuclear extracts, but not in cytoplasmic extracts. Thus, cytoplasmic extracts from IL-4-stimulated cells were devoid of Stat6 DNA binding activity despite the presence of phosphorylated Stat6. Addition of cytoplasmic extracts to nuclear extracts did not inhibit Stat6 DNA binding present in the nuclear extracts. Detergent treatment restored Stat6 DNA binding activity in cytoplasmic extracts of IL-4-stimulated cells. Thus, DNA binding activity of cytoplasmic phosphorylated Stat6 is masked by a factor dissociable by detergent treatment.
Collapse
Affiliation(s)
- Michael O Daines
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
| | | | | | | | | |
Collapse
|
34
|
Benekli M, Baer MR, Baumann H, Wetzler M. Signal transducer and activator of transcription proteins in leukemias. Blood 2003; 101:2940-54. [PMID: 12480704 DOI: 10.1182/blood-2002-04-1204] [Citation(s) in RCA: 247] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins are a 7-member family of cytoplasmic transcription factors that contribute to signal transduction by cytokines, hormones, and growth factors. STAT proteins control fundamental cellular processes, including survival, proliferation, and differentiation. Given the critical roles of STAT proteins, it was hypothesized that inappropriate or aberrant activation of STATs might contribute to cellular transformation and, in particular, leukemogenesis. Constitutive activation of mutated STAT3 has in fact been demonstrated to result in transformation. STAT activation has been extensively studied in leukemias, and mechanisms of STAT activation and the potential role of STAT signaling in leukemogenesis are the focus of this review. A better understanding of mechanisms of dysregulation of STAT signaling pathways may serve as a basis for designing novel therapeutic strategies that target these pathways in leukemia cells.
Collapse
Affiliation(s)
- Mustafa Benekli
- Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | |
Collapse
|
35
|
Stütz AM, Pickart LA, Trifilieff A, Baumruker T, Prieschl-Strassmayr E, Woisetschläger M. The Th2 cell cytokines IL-4 and IL-13 regulate found in inflammatory zone 1/resistin-like molecule alpha gene expression by a STAT6 and CCAAT/enhancer-binding protein-dependent mechanism. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1789-96. [PMID: 12574343 DOI: 10.4049/jimmunol.170.4.1789] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The onset of allergic inflammation in the lung is driven by a complex genetic program. This study shows that found in inflammatory zone (FIZZ)1 and FIZZ2, but not FIZZ3, gene expression was up-regulated 6 h after Ag challenge in a mouse model of acute pulmonary inflammation. Induction of both genes was abolished in allergen-challenged STAT6-deficient mice. FIZZ1, but not FIZZ2, mRNA was up-regulated upon incubation of the myeloid cell line BMnot with IL-4. The promoter region of FIZZ1 contains functional binding sites for STAT6 and C/EBP. FIZZ1 promoter reporter gene constructs responded to IL-4 and IL-13 stimulation in transiently transfected cells. Point mutations in the STAT6 or the C/EBP site led to loss of cytokine responsiveness indicating that IL-4-mediated induction of murine FIZZ1 is orchestrated by the coordinate action of STAT6 and C/EBP. It is concluded that the expression of the genes encoding FIZZ1 and FIZZ2, but not FIZZ3, is induced in allergen-challenged lungs in a STAT6-dependent fashion. STAT6 directly regulates IL-4- and IL-13-triggered induction of FIZZ1 expression at the transcriptional level by cooperation with C/EBP. Induction of FIZZ2 gene expression most likely occurs independent of a direct effect by these cytokines and may be due to indirect STAT6-driven mechanisms.
Collapse
Affiliation(s)
- Adrian M Stütz
- Department of Allergic Diseases, Novartis Research Institute, Brunnerstrasse 59, A-1630 Vienna, Austria
| | | | | | | | | | | |
Collapse
|
36
|
Vidarsson H, Mikaelsdottir EK, Rafnar T, Bertwistle D, Ashworth A, Eyfjord JE, Valgeirsdottir S. BRCA1 and BRCA2 bind Stat5a and suppress its transcriptional activity. FEBS Lett 2002; 532:247-52. [PMID: 12459499 DOI: 10.1016/s0014-5793(02)03684-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Germline mutations in the breast cancer susceptibility genes, BRCA1 and BRCA2, are thought to account for a large portion of familial breast cancer. The increased risk of breast cancer in women carrying such mutations suggests that these proteins play a critical role in the growth regulation of mammary epithelial cells. Another protein, Stat5a, is known to be essential for growth and terminal differentiation of breast epithelial cells. Here we show that Stat5a forms a complex with both BRCA1 and BRCA2 in breast epithelial cells upon stimulation with prolactin. In addition, we show that the activity of Stat5a on the beta-casein promoter is modulated by both BRCA1 and BRCA2. This interaction may be important during the expansion and terminal differentiation of breast epithelial cells, as happens during pregnancy and lactation.
Collapse
Affiliation(s)
- H Vidarsson
- Molecular and Cell Biology Research Laboratory, Icelandic Cancer Society, Reykjavik, Iceland
| | | | | | | | | | | | | |
Collapse
|
37
|
Andrews RP, Ericksen MB, Cunningham CM, Daines MO, Hershey GKK. Analysis of the life cycle of stat6. Continuous cycling of STAT6 is required for IL-4 signaling. J Biol Chem 2002; 277:36563-9. [PMID: 12121972 DOI: 10.1074/jbc.m200986200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription (Stat)6 is a transcription factor important for the development of Th2 cells and regulation of gene expression by IL-4 and IL-13. It is known that Stat6 is rapidly activated in response to IL-4; however, the fate of activated Stat6 is less clear. We examined the fate of activated Stat6 and found that during continuous exposure to IL-4, Stat6 activity was sustained for 72 h and that the maintenance of a constant level of activated Stat6 did not require new protein synthesis. In contrast, when cells were pulsed with IL-4 and then incubated in the absence of IL-4, the half-life of Stat6 phosphorylation and DNA binding activity was less than 1 h. Stat6 did not accumulate in the nucleus, and protein degradation did not play a major role in the disappearance of activated Stat6. Inhibition of kinase activity by staurosporine or the JAK inhibitor, AG490, revealed that maintenance of Stat6 activation in the continuous presence of IL-4 required ongoing phosphorylation of latent cytoplasmic Stat6 molecules. Cells treated with an inhibitor of nuclear export, leptomycin B, were unable to maintain Stat6 activation. Thus, the maintenance of Stat6 activation requires a constant cycle of activation, deactivation, nuclear export, and reactivation.
Collapse
Affiliation(s)
- Ryan P Andrews
- Division of Allergy and Immunology, Department of Pediatrics, Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
| | | | | | | | | |
Collapse
|
38
|
Hörtner M, Nielsch U, Mayr LM, Johnston JA, Heinrich PC, Haan S. Suppressor of cytokine signaling-3 is recruited to the activated granulocyte-colony stimulating factor receptor and modulates its signal transduction. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:1219-27. [PMID: 12133942 DOI: 10.4049/jimmunol.169.3.1219] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
G-CSF is a polypeptide growth factor used in treatment following chemotherapy. G-CSF regulates granulopoiesis and acts on its target cells by inducing homodimerization of the G-CSFR, thereby activating intracellular signaling cascades. The G-CSFR encompasses four tyrosine motifs on its cytoplasmic tail that have been shown to recruit a number of regulatory proteins. Suppressor of cytokine signaling 3 (SOCS-3), also referred to as cytokine-inducible Src homolgy 2-containing protein 3, is a member of a recently discovered family of feedback inhibitors that have been shown to inhibit the Janus kinase/STAT pathway. In this study, we demonstrate that human SOCS-3 is rapidly induced by G-CSF in polymorphonuclear neutrophils as well as in the myeloid precursor cell line U937 and that SOCS-3 negatively regulates G-CSFR-mediated STAT activation. Most importantly, we show that SOCS-3 is recruited to the G-CSFR in a phosphorylation-dependent manner and we identify phosphotyrosine (pY)729 as the major recruitment site for SOCS-3. Furthermore, we demonstrate that SOCS-3 directly binds to this pY motif. Surface plasmon resonance analysis reveals a dissociation constant (K(D)) for this interaction of around 2.8 microM. These findings strongly suggest that the recruitment of SOCS-3 to pY729 is important for the modulation of G-CSFR-mediated signal transduction by SOCS-3.
Collapse
|
39
|
Vassilev AO, Lorenz DR, Tibbles HE, Uckun FM. Role of the leukemia-associated transcription factor STAT3 in platelet physiology. Leuk Lymphoma 2002; 43:1461-7. [PMID: 12389630 DOI: 10.1080/1042819022386716] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Actinomycin D, a transcriptional inhibitor, was found to inhibit platelet potentiation by thrombopoietin (TPO), suggesting that TPO stimulation of platelets involves mitochondrial transcription. We sought to determine a possible role for leukemia-associated signal transducers and activators of transcription (STAT) proteins as mitochondrial transcription factors, focusing specifically on STAT3 in human platelets. We found TPO stimulation of platelets activated STAT3 in vitro, that STAT3 was present in platelet mitochondrial-rich fractions as determined by Western Blot analysis and was capable of binding to the regulatory D-loop region of human mitochondrial DNA upon activation. These results suggest that platelet signaling pathways activated by TPO may affect mitochondrial transcription via activation of STAT3.
Collapse
Affiliation(s)
- Alexei O Vassilev
- Department of Biochemistry, Parker Hughes Cancer Center, Parker Hughes Institute, St. Paul, MN 55113, USA
| | | | | | | |
Collapse
|
40
|
Carsol JL, Gingras S, Simard J. Synergistic action of prolactin (PRL) and androgen on PRL-inducible protein gene expression in human breast cancer cells: a unique model for functional cooperation between signal transducer and activator of transcription-5 and androgen receptor. Mol Endocrinol 2002; 16:1696-710. [PMID: 12089361 DOI: 10.1210/mend.16.7.0875] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The signal transducer and activator of transcription 5 (Stat5) has been shown to cooperate with some nuclear receptors. However, an interaction has never been demonstrated with the androgen receptor (AR). Given that the PRL-inducible protein/gross cystic disease fluid-15 (PIP/GCDFP-15) is both a PRL-controlled and an androgen-controlled protein, we used its promoter region to investigate the potential interaction between Stat5 and androgen receptor. Dihydrotestosterone or PRL alone slightly modulated or did not modulate the luciferase activity of all reporter gene constructs. In contrast, a maximal increase was observed using the -1477+42 reporter gene construct after exposure to both dihydrotestosterone and PRL. The requirement of half-site androgen-responsive elements and two consensus Stat5-binding elements, Stat5#1 and Stat5#2, was determined by site-directed mutagenesis. Activated Stat5B binds with a higher affinity to Stat5#2 than to Stat5#1. Stat5ADelta749 and Stat5BDelta754 mutants demonstrated that the Stat5 trans-activation domain is involved in the hormonal cooperation. The cooperation depends on the PRL-induced phosphorylation on Tyr(694) in Stat5A and Tyr(699) in Stat5B, as demonstrated using the Stat5AY694F and Stat5BY699F proteins. The use of AR Q798E, C619Y, and C784Y mutants showed that trans-activation, DNA-binding, and ligand-binding domains of AR are essential. Our study thus suggests a functional cooperation between AR and Stat5.
Collapse
Affiliation(s)
- Jean-Louis Carsol
- Canada Research Chair in Oncogenetics, Oncology and Molecular Endocrinology Research Center, Laval University Medical Center and Laval University, Québec, Canada G1V 4G2
| | | | | |
Collapse
|
41
|
Foley HA, Ofori-Acquah SF, Yoshimura A, Critz S, Baliga BS, Pace BS. Stat3 beta inhibits gamma-globin gene expression in erythroid cells. J Biol Chem 2002; 277:16211-9. [PMID: 11856732 DOI: 10.1074/jbc.m106556200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We demonstrated previously gamma-globin gene inhibition in K562 cells and primary erythroid progenitors treated with interleukin-6. Although several cis-acting elements have been identified in the globin promoters, the precise mechanism for cytokine-mediated globin gene regulation remains to be elucidated. In this report we demonstrate inhibitors of Stat3 phosphorylation abrogate interleukin-6-mediated gamma gene silencing in erythroid cells. DNA-protein binding studies established Stat3 interaction in the 5'-untranslated gamma-globin promoter region. Furthermore, co-transfection experiments with Stat3 beta demonstrate gamma promoter inhibition in a concentration-dependent manner, which was significantly reversed when the cognate Stat3-binding site in the 5'-untranslated region was mutated. These studies establish a novel mechanism for gamma gene silencing through the STAT signal transduction pathway.
Collapse
Affiliation(s)
- Heather A Foley
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama 36688, USA
| | | | | | | | | | | |
Collapse
|
42
|
Abstract
Activated T lymphocytes play an important role in autoimmune disease. The process of T-cell activation is therefore of significant importance in understanding the pathogenesis of many rheumatic diseases. This process can be observed from outside the lymphocyte, but we have also gained increased understanding of many of the intracellular events of T-cell activation. This review tries to draw out the most important receptors, pathways, and transcription factors involved in the process.
Collapse
Affiliation(s)
- M Aringer
- Division of Rheumatology, Department of Internal Medicine III, University of Vienna.
| |
Collapse
|
43
|
Waris G, Siddiqui A. Interaction between STAT-3 and HNF-3 leads to the activation of liver-specific hepatitis B virus enhancer 1 function. J Virol 2002; 76:2721-9. [PMID: 11861839 PMCID: PMC135980 DOI: 10.1128/jvi.76.6.2721-2729.2002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The signal transducer and activator of transcription 3 (STAT-3), a member of the STAT family of proteins, binds to a large number of transcriptional control elements and regulates gene expression in response to cytokines. While it binds to its cognate nucleotide sequences, it has been recently shown to directly interact with other transcriptional factors in the absence of DNA. We report here one such novel interaction between STAT-3 and hepatocyte nuclear factor 3 (HNF-3) in the absence of DNA. We have identified a STAT-3 binding site within the core domain of hepatitis B virus (HBV) enhancer 1. The HBV enhancer 1 DNA-STAT-3 protein interaction is shown to be stimulated by interleukin-6 (IL-6) and epidermal growth factor, which leads to an overall stimulation of HBV enhancer 1 function and viral gene expression. Using mobility shift assays and transient transfection schemes, we demonstrate a cooperative interaction between HNF-3 and STAT-3 in mediating the cytokine-mediated HBV enhancer function. Cytokine stimulation of HBV gene expression represents an important regulatory scheme of direct relevance to liver disease pathogenesis associated with HBV infection.
Collapse
Affiliation(s)
- Gulam Waris
- Department of Microbiology and Program in Molecular Biology, University of Colorado Health Sciences Center, Denver, Colorado 80262
| | | |
Collapse
|
44
|
Litterst CM, Pfitzner E. Transcriptional activation by STAT6 requires the direct interaction with NCoA-1. J Biol Chem 2001; 276:45713-21. [PMID: 11574547 DOI: 10.1074/jbc.m108132200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription 6 (STAT6) is a transcription factor that is activated by interleukin-4 (IL-4)-induced tyrosine phosphorylation and mediates most of the IL-4-induced gene expression. Transcriptional activation by STAT6 requires the interaction with coactivators like p300 and the CREB-binding protein (CBP). In this study we have investigated the function of the CBP-associated members of the p160/steroid receptor coactivator family in the transcriptional activation by STAT6. We found that only one of them, NCoA-1, acts as a coactivator for STAT6 and interacts directly with the transactivation domain of STAT6. The N-terminal part of NCoA-1 interacts with the far C-terminal part of the STAT6 transactivation domain but does not interact with the other members of the STAT family. This domain of NCoA-1 has a strong inhibitory effect on STAT6-mediated transactivation when overexpressed in cells, illustrating the importance of NCoA-1 for STAT6-mediated transactivation. In addition, we showed that both coactivators CBP and NCoA-1 bind independently to specific regions within the STAT6 transactivation domain. Our results suggest that multiple contacts between NCoA-1, CBP, and STAT6 are required for transcriptional activation. These findings provide new mechanistic insights into how STAT6 can recruit coactivators required for IL-4-dependent transactivation.
Collapse
Affiliation(s)
- C M Litterst
- Georg-Speyer-Haus, Institute for Biomedical Research, Paul-Ehrlich-Strasse 42-44, 60596 Frankfurt, Germany
| | | |
Collapse
|
45
|
Bienvenu F, Gascan H, Coqueret O. Cyclin D1 represses STAT3 activation through a Cdk4-independent mechanism. J Biol Chem 2001; 276:16840-7. [PMID: 11279133 DOI: 10.1074/jbc.m100795200] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
STAT3 transcription factors are cytoplasmic proteins that induce gene activation in response to cytokine receptor stimulation. Following tyrosine phosphorylation, STAT3 proteins dimerize, translocate into the nucleus, and activate specific target genes. Activation is transient, and down-regulation of STAT3 signaling occurs within a few hours. In this study, we show that cyclin D1 inhibits STAT3 activation. In co-immunoprecipitation and pull-down assays, cyclin D1 was found to associate with the activation domain of STAT3 upon interleukin-6 stimulation. Overexpression of cyclin D1 inhibited transcriptional activation by STAT3 proteins. This effect was not shared by cyclin E, was independent of association with Cdk4, and was unaffected by inhibitors of Cdk4. Whereas cyclin D1 had no effect on the steady-state level of STAT3 proteins in the cytoplasm, it was found to reduce the STAT3 nuclear level in HepG2 cells. These results suggest a model by which cyclin D1 is part of a feedback network controlling the down-regulation of STAT3 activity and highlight a new activity for this cell cycle regulatory protein.
Collapse
Affiliation(s)
- F Bienvenu
- INSERM EMI-U 9928, Centre Hospitalier Universitaire Angers, 4 rue Larrey, 49033 Angers Cedex, France
| | | | | |
Collapse
|
46
|
Oakley GG, Roe AL, Blouin RA, Twaroski TP, Ganguly TC, Vore M, Lehmler HJ, Robertson LW. 2,4,4'-trichlorobiphenyl increases STAT5 transcriptional activity. Mol Carcinog 2001; 30:199-208. [PMID: 11346882 DOI: 10.1002/mc.1029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The promoting effects of polychlorinated biphenyls (PCBs) have been studied extensively in a variety of two-stage carcinogenesis models. However, the molecular mechanisms responsible for the promotion effects of PCBs have not been elucidated. We measured the effect of PCBs on DNA-binding proteins involved in cell proliferation and transformation. Male Sprague-Dawley rats were injected intraperitoneally with mono-, di-, tri-, tetra-, or hexachlorobiphenyls (300 micromol/kg/d) each day for 4 d and killed 4 h after the last injection. To detect alterations in nuclear proteins that could explain the tumor-promoter activity of PCBs, liver nuclear extracts were analyzed by electrophoretic mobility shift assays. Electrophoretic mobility shift assay analysis of signal transducers and activators of transcription (STAT)-binding activity to a consensus gamma-interferon-activated sequence (GAS) element was compared in liver nuclear extracts from treated rats. STAT-binding activity was eightfold to tenfold higher in nuclear extracts from animals treated with 2,4,4'-trichloro- (PCB 28) and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153). Analysis of the protein complex binding to the GAS element, with antibodies specific for STAT3, STAT5, and STAT6, indicated that the protein complex was made up of STAT5 and STAT6 proteins. HepG2 cells transiently transfected with a luciferase reporter gene construct containing many STAT5 binding sites were treated with PCB 28 and PCB 153. PCB 28 stimulated a greater than 25-fold increase in luciferase activity at the highest concentration tested, 1.0 microg/mL. However, enhanced luciferase activity did not occur with PCB 153 treatment. 4-Chlorobiphenyl (PCB 3), PCB 28, and PCB 153 treatment of Sprague-Dawley rats resulted in a large increase in protein binding to a consensus activated protein-1 (AP-1) element. However, 3,4-dichlorobiphenyl (PCB 12) and 3,3',4,4'-tetrachlorobiphenyl (PCB 77) treatments did not increase AP-1 transcription activity. Further analysis of the proteins binding to the AP-1 consensus sequence with antibodies specific for c-fos, junD, and junB indicated that the protein composition consists of junD proteins. These data showed functional differences between noncoplanar and coplanar PCBs with respect to STAT activation and AP-1-DNA binding.
Collapse
Affiliation(s)
- G G Oakley
- Graduate Center for Toxicology, University of Kentucky Chandler Medical Center, Lexington 40536-0305, USA
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Shen Y, Darnell JE. Antiviral response in cells containing Stat1 with heterologous transactivation domains. J Virol 2001; 75:2627-33. [PMID: 11222685 PMCID: PMC115886 DOI: 10.1128/jvi.75.6.2627-2633.2001] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The STATs (signal transducers and activators of transcription), latent cytoplasmic transcription factors, are activated by binding of extracellular polypeptides to cell surface receptors. Dimerization, accumulation in the nucleus, and transcriptional inductions of specific genes then occur. The COOH terminus of the STATs acts as a transcriptional activation domain (TAD). Stat1, one of seven mammalian STAT genes, forms a homodimer after activation by gamma interferon and induces transcription of a number of genes. These induced genes in turn produce the antiviral state. In the present experiments we used a Stat1-deficient cell line complemented with Stat1 or various fusion constructs in which the wild-type Stat1 TAD was replaced by other TADs to test the possibility that a specific activating domain was necessary for the induction of the antiviral response. We found that a wide variety of TADs with different activation potential appended to the Stat1 COOH terminus could substitute for the wild-type protein in inducing the antiviral state.
Collapse
Affiliation(s)
- Y Shen
- Laboratory of Molecular Cell Biology, The Rockefeller University, New York, New York 10021, USA
| | | |
Collapse
|
48
|
Lavender P, Cousins D, Smith P, Lee T. Presentation at the National Asthma Campaign International Congress, June 1999. Controlling the inflammatory response through transcriptional mechanisms. Clin Exp Allergy 2000; 30:1697-708. [PMID: 11122207 DOI: 10.1046/j.1365-2222.2000.01010.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- P Lavender
- Department of Respiratory Medicine & Allergy, GKT School of Medicine, Guys Campus, London SE1 9RT, UK
| | | | | | | |
Collapse
|
49
|
Cans C, Mangano R, Barilá D, Neubauer G, Superti-Furga G. Nuclear tyrosine phosphorylation: the beginning of a map. Biochem Pharmacol 2000; 60:1203-15. [PMID: 11007959 DOI: 10.1016/s0006-2952(00)00434-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tyrosine phosphorylation is usually associated with cytoplasmic events. Yet, over the years, many reports have accumulated on tyrosine phosphorylation of individual molecules in the nucleus, and several tyrosine kinases and phosphatases have been found to be at least partially nuclear. The question arises as to whether nuclear tyrosine phosphorylation represents a collection of loose ends of events originating in the cytoplasm or if there may be intranuclear signaling circuits relying on tyrosine phosphorylation to regulate specific processes. The recent discovery of a mechanism causing nuclear tyrosine phosphorylation has prompted us to review the cumulative evidence for nuclear tyrosine phosphorylation pathways and their possible role. While we found that no complex nuclear function has yet been shown to rely upon intranuclear tyrosine phosphorylation in an unambiguous fashion, we found a very high number of compelling observations on individual molecules that suggest underlying networks linking individual events. A systematic proteomics approach to nuclear tyrosine phosphorylation should help chart possible interaction pathways.
Collapse
Affiliation(s)
- C Cans
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | | | | | | |
Collapse
|
50
|
Begitt A, Meyer T, van Rossum M, Vinkemeier U. Nucleocytoplasmic translocation of Stat1 is regulated by a leucine-rich export signal in the coiled-coil domain. Proc Natl Acad Sci U S A 2000; 97:10418-23. [PMID: 10973496 PMCID: PMC27039 DOI: 10.1073/pnas.190318397] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2000] [Accepted: 07/10/2000] [Indexed: 12/11/2022] Open
Abstract
Signal transducer and activator of transcription (Stat) proteins are latent transcription factors that reside in the cytoplasm before activation. On cytokine-induced tyrosine phosphorylation, these molecules dimerize and accumulate transiently in the nucleus. No specific signals mediating these processes have been identified to date. In this report, we examine the nuclear export of Stat1. We find that treatment of cells with the export inhibitor leptomycin B does not affect steady-state localization of Stat1 but impedes nuclear export after IFNgamma-induced nuclear accumulation. We identify a conserved leucine-rich helical segment in the coiled-coil domain of Stat1, which is responsible for the efficient nuclear export of this protein. Mutation of two hallmark leucines within this segment greatly attenuate the back transport of Stat1 in the cytoplasm. When fused to a carrier protein, the Stat1 export sequence can mediate nuclear export after intranuclear microinjection. We show that prolonging the nuclear presence of Stat1 by inhibiting nuclear export reduces the transcriptional response to stimulation with IFNgamma. These data suggest that Stats are actively exported from the nucleus via several separate pathways and link this activity to transcriptional activation.
Collapse
Affiliation(s)
- A Begitt
- Nachwuchsgruppe Zelluläre Signalverarbeitung, Forschungsinstitut für Molekulare Pharmakologie, and Freie Universität, Institut für Kristallographie, D-10315 Berlin, Germany
| | | | | | | |
Collapse
|