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A Novel Chalcone Derivative Regulates the Expression and Phosphorylation of ERK1/2 by Inhibiting Fli-1 Promoter Activity for Preventing the Malignant Progression of Erythroleukemia. Catalysts 2022. [DOI: 10.3390/catal13010084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acute erythroleukemia is a rare form of acute myeloid leukemia recognized by its distinct phenotypic attribute of erythroblasts proliferation. In this study, in vitro experiments showed that a newly synthesized chalcone (ZH-254) inhibited cell proliferation, caused apoptosis, arrested the cell cycle in the G1 phase, and downregulated Fli-1 expression by inhibiting Fli-1 promoter activity. In vivo experiments showed that ZH-254 could effectively alleviate splenomegaly and prolong the survival of erythroleukemia mice. RT-PCR and Western blot analysis showed that ZH-254 could regulate the expression of Fli-1 target genes and G1-phase-related cell cycle proteins, including Rb, Bcl-2, Bax, ERK1/2, Gata-1, P110, SHIP-1, p-ERK1, CDK4, C-myc, Cyclin D1, Smad-3, GSK-3, and p21. Among them, the compound most significantly regulated the expression and phosphorylation of ERK1, the target gene of Fli-1 involved in regulating cell proliferation and apoptosis. Thus, ZH-254 restricts the malignancy of erythroleukemia by causing the inactivation of Fli-1 expression via suppressing its promoter activity, further regulating the expression and phosphorylation of ERK1- and G1-phase-related genes. These results reveal the critical role of Fli-1 in the growth and survival of various hematological malignancies and point to chalcone derivatives as lead compounds for the development of anti-Fli-1 drugs for the treatment of erythroleukemia with overexpression of Fli-1.
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Hemida AS, Holah NS. Expression of Friend Leukemia Integration-1 (Fli-1) and the Apoptosis Regulator B Cell Lymphoma-2 (BCL-2) in Gastric Carcinoma; an Immunohistochemical Study. J Immunoassay Immunochem 2021; 43:1954948. [PMID: 34314292 DOI: 10.1080/15321819.2021.1954948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Fli-1 regulates multiple biological functions in different cancers particularly Ewing sarcoma and leukemias. There are controversial reports regarding function and prognostic significance of Fli-1 in epithelial cancer including gastric carcinoma (GC). No previous reports examined relationship between Fli-1 and BCL-2 in GC. This study aimed to investigate the expression of Fli-1 and BCL-2 in GC and expected the prognostic significance of their expression. Study was carried out on 88 gastric specimens (58 GC and 30 chronic gastritis cases). Immunohistochemical staining for Fli-1 and BCL-2 was done. There was significant lower Fli-1 and BCL-2 expression in GC than chronic gastritis. Advanced tumor stage showed significant relation with both low Fli-1 expression and negative BCL-2 expression. There was significant direct correlation between BCL-2 positivity and Fli-1 expression in GC. Cox-regression analysis showed that distant metastasis was the first independent factor affecting patients' OS. Fli-1 could act as tumor-suppressor protein involved in GC carcinogenesis. In addition, both Fli-1 and BCL-2 may be used as good prognostic markers in GC. The direct correlation between BCL-2 and Fli-1 expression could potentiate Fli-1 and BCL-2 as therapeutic targets in GC, acting together to inhibit cellular proliferation.
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Affiliation(s)
- Aiat Shaban Hemida
- Pathology Department, Faculty of Medicine, Menoufia University, Shebin El Kom, Egypt
| | - Nanis Shawky Holah
- Pathology Department, Faculty of Medicine, Menoufia University, Shebin El Kom, Egypt
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Xie B, Hu F, Li M, Mo L, Xu C, Xiao Y, Wang X, Nie J, Yang L, He Y. FLI-1 mediates tumor suppressor function via Klotho signaling in regulating CRC. Cell Biol Int 2020; 44:1514-1522. [PMID: 32196848 DOI: 10.1002/cbin.11347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 12/24/2022]
Abstract
Colorectal cancer (CRC) is an aggressive malignancy with a high incidence and mortality rate. Although a targeting therapy has been developed, the 5-year survival rate is still very low in CRC patients with distant metastasis. Thus, the identification of new targets is still significant for improving CRC treatment. Klotho is a tumor suppressor, and its expression is aberrant in CRC. In this study, the roles of the FLI-1 gene in regulating Klotho gene expression and Klotho-associated signaling, as well as the effects of FLI-1 on colony formation, invasion, and apoptosis were investigated in CRC cell lines. The methylation of the FLI-1 gene was analyzed using a commercial methylation kit. Results showed that FLI-1 messenger RNA and protein expression were downregulated in six CRC cell lines when compared with the normal colon mucosal epithelial cell line, which negatively correlated with the level of DNA methylation. Silencing of FLI-1 gene expression decreased Klotho protein expression and phosphorylation of β-catenin protein at Thr41 /Ser45 , but increased Wnt3a and β-catenin protein expression and IGF-1R phosphorylation in HT29 cells. In contrast to silencing FLI-1, overexpressing FLI-1 significantly increased Klotho protein expression and phosphorylation of β-catenin protein at Thr41 /Ser45 , but decreased Wnt3a and β-catenin protein expression and IGF-1R phosphorylation in Caco-2 cells. Silencing of FLI-1 gene expression significantly increased colony formation and invasion, but decreased apoptosis in HT29 cells. In contrast, overexpressing the FLI-1 gene significantly decreased colony formation and invasion, but increased apoptosis in Caco-2 cells. These findings suggest that FLI-1 functions as a tumor suppressor in CRC cells and positively regulates Klotho signaling. Hypermethylation may be one of the causes of the loss of FLI-1 gene expression in CRC cells.
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Affiliation(s)
- Biao Xie
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Fan Hu
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Mei Li
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Li Mo
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Chongsi Xu
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - You Xiao
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Xiaoyan Wang
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
| | - Jing Nie
- Hunan Slack King Laboratory Animal Co., Ltd., Changsha, 410125, Hunan, China
| | - Lixia Yang
- Department of Cancer, The First Affiliated Hospital of Changsha Medical School, Changsha, 410219, Hunan, China
| | - Yongheng He
- Department One of Anorectal Surgery, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, 410005, Hunan, China
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Song J, Yuan C, Yang J, Liu T, Yao Y, Xiao X, Gajendran B, Xu D, Li Y, Wang C, Liu W, Wen M, Spaner D, Filmus J, Zacksenhaus E, Zhang Y, Hao X, Ben‐David Y. Novel flavagline‐like compounds with potent Fli‐1 inhibitory activity suppress diverse types of leukemia. FEBS J 2018; 285:4631-4645. [DOI: 10.1111/febs.14690] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/15/2018] [Accepted: 10/31/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Jialei Song
- The Laboratory of Cell Biochemistry and Topogenic Regulation College of Bioengineering and Faculty of Sciences Chongqing University China
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Chunmao Yuan
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Jue Yang
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Tangjingjun Liu
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Yao Yao
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Xiao Xiao
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Babu Gajendran
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Dahai Xu
- Department of Anatomy Norman Bethune College of Medicine Jilin University Changchun China
| | - You‐Jun Li
- Department of Anatomy Norman Bethune College of Medicine Jilin University Changchun China
| | - Chunlin Wang
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Wuling Liu
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Min Wen
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - David Spaner
- Biology Platform Sunnybrook Research Institute Toronto Canada
| | - Jorge Filmus
- Biology Platform Sunnybrook Research Institute Toronto Canada
| | - Eldad Zacksenhaus
- Department of Medicine University of Toronto Canada
- Division of Advanced Diagnostics Toronto General Research Institute University Health Network Toronto Canada
| | - Yiguo Zhang
- The Laboratory of Cell Biochemistry and Topogenic Regulation College of Bioengineering and Faculty of Sciences Chongqing University China
| | - Xiaojiang Hao
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
| | - Yaacov Ben‐David
- State Key Laboratory for Functions and Applications of Medicinal Plants Guizhou Medical University Guiyang China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences Guiyang China
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A novel synthesized 3’, 5’-diprenylated chalcone mediates the proliferation of human leukemia cells by regulating apoptosis and autophagy pathways. Biomed Pharmacother 2018; 106:794-804. [DOI: 10.1016/j.biopha.2018.06.153] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 06/22/2018] [Accepted: 06/27/2018] [Indexed: 12/29/2022] Open
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Vecchiarelli-Federico LM, Liu T, Yao Y, Gao Y, Li Y, Li YJ, Ben-David Y. Fli-1 overexpression in erythroleukemic cells promotes erythroid de-differentiation while Spi-1/PU.1 exerts the opposite effect. Int J Oncol 2017; 51:456-466. [PMID: 28586009 PMCID: PMC5505126 DOI: 10.3892/ijo.2017.4027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/23/2017] [Indexed: 01/21/2023] Open
Abstract
The ETS transcription factors play a critical role during hematopoiesis. In F-MuLV-induced erythroleukemia, Fli-1 insertional activation producing high expression of this transcription factor required to promote proliferation. How deregulated Fli-1 expression alters the balance between erythroid differentiation and proliferation is unknown. To address this issue, we exogenously overexpressed Fli-1 in an erythroleukemic cell harboring activation of spi-1/PU.1, another ETS gene involved in erythroleukemogenesis. While the proliferation in culture remains unaffected, Fli-1 overexpression imparts morphological and immunohistochemical characteristics of immature erythroid progenitors. Fli-1 overexpression in erythroleukemic cells increased the numbers of erythroid colonies on methylcellulose and reduced tumorigenicity as evidenced by increase latency of erythroleukemogenesis in mice inoculated with these cells. Although all transplanted mice developed enlargement of the spleen and liver due to leukemic infiltration, Fli-1 overexpression altered the hematopoietic phenotype, significantly increasing the expression of regulatory hematopoietic genes cKIT, SCA-1, CD41 and CD71. In contrast, expression of Spi-1/PU.1 in a Fli-1 producing erythroleukemia cell line in which fli-1 is activated, resulted in increased proliferation through activation of growth promoting proteins MAPK, AKT, cMYC and JAK2. Importantly, these progenitors express high levels of markers such as CD71 and TER119 associated with more mature erythroid cells. Thus, Fli-1 overexpression induces a de-differentiation program by reverting CFU-E to BFU-E erythroid progenitor activity, while Spi-1/PU.1 promoting maturation from BFU-E to CFU-E.
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Affiliation(s)
| | - Tangjingjun Liu
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou 550014, P.R. China
| | - Yao Yao
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou 550014, P.R. China
| | - Yuanyuan Gao
- Department of Anatomy, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yanmei Li
- Molecular and Cellular Biology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - You-Jun Li
- Department of Anatomy, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yaacov Ben-David
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou 550014, P.R. China
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Sundararaj KP, Thiyagarajan T, Molano I, Basher F, Powers TW, Drake RR, Nowling TK. FLI1 Levels Impact CXCR3 Expression and Renal Infiltration of T Cells and Renal Glycosphingolipid Metabolism in the MRL/lpr Lupus Mouse Strain. THE JOURNAL OF IMMUNOLOGY 2015; 195:5551-60. [PMID: 26538397 DOI: 10.4049/jimmunol.1500961] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022]
Abstract
The ETS factor Friend leukemia virus integration 1 (FLI1) is a key modulator of lupus disease expression. Overexpressing FLI1 in healthy mice results in the development of an autoimmune kidney disease similar to that observed in lupus. Lowering the global levels of FLI1 in two lupus strains (Fli1(+/-)) significantly improved kidney disease and prolonged survival. T cells from MRL/lpr Fli1(+/-) lupus mice have reduced activation and IL-4 production, neuraminidase 1 expression, and the levels of the glycosphingolipid lactosylceramide. In this study, we demonstrate that MRL/lpr Fli1(+/-) mice have significantly decreased renal neuraminidase 1 and lactosylceramide levels. This corresponds with a significant decrease in the number of total CD3(+) cells, as well as CD4(+) and CD44(+)CD62L(-) T cell subsets in the kidney of MRL/lpr Fli1(+/-) mice compared with the Fli1(+/+) nephritic mice. We further demonstrate that the percentage of CXCR3(+) T cells and Cxcr3 message levels in T cells are significantly decreased and correspond with a decrease in renal CXCR3(+) cells and in Cxcl9 and Cxcl10 expression in the MRL/lpr Fli1(+/-) compared with the Fli1(+/+) nephritic mice. Our results suggest that reducing the levels of FLI1 in MRL/lpr mice may be protective against development of nephritis in part through downregulation of CXCR3, reducing renal T cell infiltration and glycosphingolipid levels.
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Affiliation(s)
- Kamala P Sundararaj
- Division of Rheumatology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Thirumagal Thiyagarajan
- Division of Rheumatology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Ivan Molano
- Division of Rheumatology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Fahmin Basher
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425; and
| | - Thomas W Powers
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, SC 29425
| | - Richard R Drake
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, SC 29425
| | - Tamara K Nowling
- Division of Rheumatology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425;
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8
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Segura S, Efthimiadi L, Porcher C, Courtes S, Coronas V, Krantic S, Moyse E. Leptin-dependent neurotoxicity via induction of apoptosis in adult rat neurogenic cells. Front Cell Neurosci 2015; 9:350. [PMID: 26441523 PMCID: PMC4561523 DOI: 10.3389/fncel.2015.00350] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 08/21/2015] [Indexed: 12/30/2022] Open
Abstract
Adipocyte-derived hormone leptin has been recently implicated in the control of neuronal plasticity. To explore whether modulation of adult neurogenesis may contribute to leptin control of neuronal plasticity, we used the neurosphere assay of neural stem cells derived from the adult rat subventricular zone (SVZ). Endogenous expression of specific leptin receptor (ObRb) transcripts, as revealed by RT-PCR, is associated with activation of both ERK and STAT-3 pathways via phosphorylation of the critical ERK/STAT-3 amino acid residues upon addition of leptin to neurospheres. Furthermore, leptin triggered withdrawal of neural stem cells from the cell cycle as monitored by Ki67 labeling. This effect was blocked by pharmacological inhibition of ERK activation thus demonstrating that ERK mediates leptin effects on neural stem cell expansion. Leptin-dependent withdrawal of neural stem cells from the cell cycle was associated with increased apoptosis, as detected by TUNEL, which was preceded by cyclin D1 induction. Cyclin D1 was indeed extensively colocalized with TUNEL-positive, apoptotic nuclei. Cyclin-D1 silencing by specific shRNA prevented leptin-induced decrease of the cell number per neurosphere thus pointing to the causal relationship between leptin actions on apoptosis and cyclin D1 induction. Leptin target cells in SVZ neurospheres were identified by double TUNEL/phenotypic marker immunocytofluorescence as differentiating neurons mostly. The inhibition of neural stem cell expansion via ERK/cyclin D1-triggered apoptosis defines novel biological action of leptin which may be involved in adiposity-dependent neurotoxicity.
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Affiliation(s)
- Stéphanie Segura
- Physiologie de la Reproduction et des Comportements, UMR 85 Institut National de la Recherche Agronomique, Centre INRA de Tours, Université François Rabelais de Tours Nouzilly, France
| | - Laurie Efthimiadi
- Institut National de la Santé et de la Recherche Médicale Unité 901, Institut de Neurobiologie de la Méditerranée, Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France
| | - Christophe Porcher
- Institut National de la Santé et de la Recherche Médicale Unité 901, Institut de Neurobiologie de la Méditerranée, Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France
| | - Sandrine Courtes
- Institut National de la Santé et de la Recherche Médicale Unité 901, Institut de Neurobiologie de la Méditerranée, Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France
| | - Valérie Coronas
- Signalisation et Transports Ioniques Membranaires, ERL 7368 Centre National de la Recherche Scientifique, Université de Poitiers Poitiers, France
| | - Slavica Krantic
- Institut National de la Santé et de la Recherche Médicale Unité 901, Institut de Neurobiologie de la Méditerranée, Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Centre de Recherche des Cordeliers, UMR_S 1138 INSERM, Paris Descartes University, Sorbonne Paris Cité, Pierre and Marie Curie University Paris, France
| | - Emmanuel Moyse
- Physiologie de la Reproduction et des Comportements, UMR 85 Institut National de la Recherche Agronomique, Centre INRA de Tours, Université François Rabelais de Tours Nouzilly, France
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The ets transcription factor Fli-1 in development, cancer and disease. Oncogene 2014; 34:2022-31. [PMID: 24909161 PMCID: PMC5028196 DOI: 10.1038/onc.2014.162] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/03/2014] [Accepted: 05/04/2014] [Indexed: 12/13/2022]
Abstract
Friend Leukemia Virus Induced erythroleukemia-1 (Fli-1), an ETS transcription factor, was isolated a quarter century ago through a retrovirus mutagenesis screen. Fli-1 has since been recognized to play critical roles in normal development and homeostasis. For example, it transcriptionally regulates genes that drive normal hematopoiesis and vasculogenesis. Indeed, Fli-1 is one of 10 key regulators of hematopoietic stem/progenitor cell maintenance and differentiation. Aberrant expression of Fli-1 also underlies a number of virally induced leukemias, including Friend virus-induced erythroleukemia and various types of human cancers, and it is the target of chromosomal translocations in childhood Ewing’s sarcoma. Abnormal expression of Fli-1 is important in the aetiology of auto-immune diseases such as Systemic Lupus Erythematosus (SLE) and Systemic Sclerosis (SSc). These studies establish Fli-1 as a strong candidate for drug development. Despite difficulties in targeting transcription factors, recent studies identified small molecule inhibitors for Fli-1. Here we review past and ongoing research on Fli-1 with emphasis on its mechanistic function in autoimmune disease and malignant transformation. The significance of identifying Fli-1 inhibitors and their clinical applications for treatment of disease and cancer with deregulated Fli-1 expression are discussed.
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Mejia-Pous C, Damiola F, Gandrillon O. Cholesterol synthesis-related enzyme oxidosqualene cyclase is required to maintain self-renewal in primary erythroid progenitors. Cell Prolif 2011; 44:441-52. [PMID: 21951287 DOI: 10.1111/j.1365-2184.2011.00771.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES Molecular mechanisms controlling cell fate decision making in self-renewing cells are poorly understood. A previous transcriptomic study, carried out in primary avian erythroid progenitor cells (T2ECs), revealed that the gene encoding oxidosqualene cyclase (OSC/LSS), an enzyme involved in cholesterol biosynthesis, is significantly up-regulated in self-renewing cells. The aim of the present work is to understand whether this up-regulation is required for self-renewal maintenance and what are the mechanisms involved. MATERIALS AND METHODS To investigate OSC function, we studied effects of its enzymatic activity inhibition using Ro48-8071, a specific OSC inhibitor. In addition, we completed this pharmacological approach by RNAi-mediated OSC/LSS knockdown. The study of OSC inhibition was carried out on both self-renewing and differentiating cells to observe any state-dependent effect. RESULTS Our data show that OSC acts both by protecting self-renewing T2EC cells from apoptosis and by blocking their differentiation program, as OSC inhibition is sufficient to trigger spontaneous commitment of self-renewing cells towards an early differentiation state. This is self-renewal specific, as OSC inhibition has no effect on erythroid progenitors that have already differentiated. CONCLUSIONS Taken together, our results suggest that OSC/LSS expression and activity are required to maintain cell self-renewal and may be involved in the self-renewal versus differentiation/apoptosis decision making, by keeping cells in a self-renewal state.
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Affiliation(s)
- C Mejia-Pous
- Bases Moléculaires de l'Autorenouvellement et de ses Altérations" Group, Université de Lyon, Université Lyon 1, Villeurbanne, Centre de Génétique Moléculaire et Cellulaire, Lyon, France
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11
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Maragno AL, Pironin M, Alcalde H, Cong X, Knobeloch KP, Tangy F, Zhang DE, Ghysdael J, Quang CT. ISG15 modulates development of the erythroid lineage. PLoS One 2011; 6:e26068. [PMID: 22022510 PMCID: PMC3192153 DOI: 10.1371/journal.pone.0026068] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 09/19/2011] [Indexed: 11/24/2022] Open
Abstract
Activation of erythropoietin receptor allows erythroblasts to generate erythrocytes. In a search for genes that are up-regulated during this differentiation process, we have identified ISG15 as being induced during late erythroid differentiation. ISG15 belongs to the ubiquitin-like protein family and is covalently linked to target proteins by the enzymes of the ISGylation machinery. Using both in vivo and in vitro differentiating erythroblasts, we show that expression of ISG15 as well as the ISGylation process related enzymes Ube1L, UbcM8 and Herc6 are induced during erythroid differentiation. Loss of ISG15 in mice results in decreased number of BFU-E/CFU-E in bone marrow, concomitant with an increased number of these cells in the spleen of these animals. ISG15(-/-) bone marrow and spleen-derived erythroblasts show a less differentiated phenotype both in vivo and in vitro, and over-expression of ISG15 in erythroblasts is found to facilitate erythroid differentiation. Furthermore, we have shown that important players of erythroid development, such as STAT5, Globin, PLC γ and ERK2 are ISGylated in erythroid cells. This establishes a new role for ISG15, besides its well-characterized anti-viral functions, during erythroid differentiation.
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Affiliation(s)
- Ana Leticia Maragno
- CNRS (Centre National de la Recherche Scientifique) UMR3306, Orsay, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) U1005, Orsay, France
- Institut Curie, Centre Universitaire, Bat 110 91405, Orsay, France
| | - Martine Pironin
- CNRS (Centre National de la Recherche Scientifique) UMR3306, Orsay, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) U1005, Orsay, France
- Institut Curie, Centre Universitaire, Bat 110 91405, Orsay, France
| | - Hélène Alcalde
- CNRS (Centre National de la Recherche Scientifique) UMR3306, Orsay, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) U1005, Orsay, France
- Institut Curie, Centre Universitaire, Bat 110 91405, Orsay, France
| | - Xiuli Cong
- University of California San Diego, Moores University of California San Diego Cancer Center, La Jolla, California, United States of America
| | | | - Frederic Tangy
- Unité de Génomique Virale et Vaccination, CNRS URA-3015, Institut Pasteur, Paris, France
| | - Dong-Er Zhang
- University of California San Diego, Moores University of California San Diego Cancer Center, La Jolla, California, United States of America
| | - Jacques Ghysdael
- CNRS (Centre National de la Recherche Scientifique) UMR3306, Orsay, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) U1005, Orsay, France
- Institut Curie, Centre Universitaire, Bat 110 91405, Orsay, France
| | - Christine Tran Quang
- CNRS (Centre National de la Recherche Scientifique) UMR3306, Orsay, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) U1005, Orsay, France
- Institut Curie, Centre Universitaire, Bat 110 91405, Orsay, France
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12
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Abnormal expression of FLI1 protein is an adverse prognostic factor in acute myeloid leukemia. Blood 2011; 118:5604-12. [PMID: 21917756 DOI: 10.1182/blood-2011-04-348052] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Friend leukemia virus integration 1 (FLI1), an Ets transcription factor family member, is linked to acute myelogenous leukemia (AML) by chromosomal events at the FLI1 locus, but the biologic impact of FLI1 expression on AML is unknown. FLI1 protein expression was measured in 511 newly diagnosed AML patients. Expression was similar in peripheral blood (PB) and BM and higher at diagnosis than at relapse (P = .02). Compared with normal CD34(+) cells, expression in AML was above or below normal in 32% and 5% of patients, respectively. Levels were negatively correlated with an antecedent hematologic disorder (P = .002) but not with age or cytogenetics. Mutated NPM1 (P = .0007) or FLT3-ITD (P < .02) had higher expression. FLI1 levels were negatively correlated with 10 of 195 proteins associated with proliferation and stromal interaction, and positively correlated (R > 0.3) with 19 others. The FLI1 level was not predictive of remission attainment, but patients with low or high FLI1 expression had shorter remission duration (22.6 and 40.3 vs 51.1 weeks, respectively; P = .01) and overall survival (45.2 and 35.4 vs 59.4 weeks, respectively; P = .03). High FLI1 levels were adverse in univariate and multivariate analysis. FLI1 expression is frequently abnormal and prognostically adverse in AML. FLI1 and/or its response genes may be therapeutically targetable to interfere with AML cell biology.
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Day BW, Stringer BW, Spanevello MD, Charmsaz S, Jamieson PR, Ensbey KS, Carter JC, Cox JM, Ellis VJ, Brown CL, Walker DG, Inglis PL, Allan S, Reynolds BA, Lickliter JD, Boyd AW. ELK4 neutralization sensitizes glioblastoma to apoptosis through downregulation of the anti-apoptotic protein Mcl-1. Neuro Oncol 2011; 13:1202-12. [PMID: 21846680 DOI: 10.1093/neuonc/nor119] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Glioma is the most common adult primary brain tumor. Its most malignant form, glioblastoma multiforme (GBM), is almost invariably fatal, due in part to the intrinsic resistance of GBM to radiation- and chemotherapy-induced apoptosis. We analyzed B-cell leukemia-2 (Bcl-2) anti-apoptotic proteins in GBM and found myeloid cell leukemia-1 (Mcl-1) to be the highest expressed in the majority of malignant gliomas. Mcl-1 was functionally important, as neutralization of Mcl-1 induced apoptosis and increased chemotherapy-induced apoptosis. To determine how Mcl-1 was regulated in glioma, we analyzed the promoter and identified a novel functional single nucleotide polymorphism in an uncharacterized E26 transformation-specific (ETS) binding site. We identified the ETS transcription factor ELK4 as a critical regulator of Mcl-1 in glioma, since ELK4 downregulation was shown to reduce Mcl-1 and increase sensitivity to apoptosis. Importantly the presence of the single nucleotide polymorphism, which ablated ELK4 binding in gliomas, was associated with lower Mcl-1 levels and a greater dependence on Bcl-xL. Furthermore, in vivo, ELK4 downregulation reduced tumor formation in glioblastoma xenograft models. The critical role of ELK4 in Mcl-1 expression and protection from apoptosis in glioma defines ELK4 as a novel potential therapeutic target for GBM.
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Affiliation(s)
- Bryan W Day
- Queensland Institute of Medical Research, P.O. Royal Brisbane Hospital, Queensland, 4029, Brisbane, Australia.
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14
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The inositol phosphatase SHIP-1 is negatively regulated by Fli-1 and its loss accelerates leukemogenesis. Blood 2010; 116:428-36. [PMID: 20445019 DOI: 10.1182/blood-2009-10-250217] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The activation of Fli-1, an Ets transcription factor, is the critical genetic event in Friend murine leukemia virus (F-MuLV)-induced erythroleukemia. Fli-1 overexpression leads to erythropoietin-dependent erythroblast proliferation, enhanced survival, and inhibition of terminal differentiation, through activation of the Ras pathway. However, the mechanism by which Fli-1 activates this signal transduction pathway has yet to be identified. Down-regulation of the Src homology 2 (SH2) domain-containing inositol-5-phosphatase-1 (SHIP-1) is associated with erythropoietin-stimulated erythroleukemic cells and correlates with increased proliferation of transformed cells. In this study, we have shown that F-MuLV-infected SHIP-1 knockout mice display accelerated erythroleukemia progression. In addition, RNA interference (RNAi)-mediated suppression of SHIP-1 in erythroleukemia cells activates the phosphatidylinositol 3-kinase (PI 3-K) and extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathways, blocks erythroid differentiation, accelerates erythropoietin-induced proliferation, and leads to PI 3-K-dependent Fli-1 up-regulation. Chromatin immunoprecipitation and luciferase assays confirmed that Fli-1 binds directly to an Ets DNA binding site within the SHIP-1 promoter and suppresses SHIP-1 transcription. These data provide evidence to suggest that SHIP-1 is a direct Fli-1 target, SHIP-1 and Fli-1 regulate each other in a negative feedback loop, and the suppression of SHIP-1 by Fli-1 plays an important role in the transformation of erythroid progenitors by F-MuLV.
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15
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Sakurai T, Kondoh N, Arai M, Hamada JI, Yamada T, Kihara-Negishi F, Izawa T, Ohno H, Yamamoto M, Oikawa T. Functional roles of Fli-1, a member of the Ets family of transcription factors, in human breast malignancy. Cancer Sci 2009; 98:1775-84. [PMID: 17727680 DOI: 10.1111/j.1349-7006.2007.00598.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The Ets family of transcription factors is implicated in malignant transformation and tumor progression, including invasion, metastasis and neo-angiogenesis. In the present study, we found that the Fli-1 gene, a member of the Ets family, was highly expressed in several breast cancer cell lines (MDA-MB231, MDA-MB436, BT-549 and HCC1395). To investigate the functional roles of Fli-1 in breast cancer malignancy, we introduced an expression plasmid containing full-length Fli-1 cDNA into MCF7 breast cancer cells in which endogenous expression of Fli-1 was barely detectable.Overexpression of Fli-1 in MCF7 cells led to inhibition of apoptosis induced by serum depletion or ultraviolet irradiation, although it did not affect cell growth rate in liquid media, colony formation in soft agar or the in vitro invasion capacity of the cells. Expression of Fli-1 and antiapoptotic bcl-2 was coordinately upregulated by serum depletion in MCF7 cells, and the upregulation was inhibited by treatment of the cells with a c-Jun-NH(2)-terminal kinase-specific inhibitor. Furthermore, expression of the bcl-2 gene and protein was enhanced in Fli-1-overexpressing MCF7 cells compared with mock-transfected cells. In addition, human bcl-2 promoter activity was transactivated by Fli-1. These results suggest that Fli-1 contributes to the malignancy of human breast cancer by inhibiting apoptosis through upregulated expression of the bcl-2 gene.
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Affiliation(s)
- Takuya Sakurai
- Department of Cell Genetics, Sasaki Institute, Kanda-Surugadai, Tokoyo 101-0062, Japan
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16
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Ajithdoss DK, Reddy SM, Suchodolski PF, Lee LF, Kung HJ, Lupiani B. In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988. Virus Res 2009; 142:57-67. [PMID: 19189855 DOI: 10.1016/j.virusres.2009.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 01/06/2009] [Accepted: 01/13/2009] [Indexed: 11/19/2022]
Affiliation(s)
- Dharani K Ajithdoss
- Department of Poultry Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
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17
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Spi-1 and Fli-1 directly activate common target genes involved in ribosome biogenesis in Friend erythroleukemic cells. Mol Cell Biol 2009; 29:2852-64. [PMID: 19289502 DOI: 10.1128/mcb.01435-08] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Spi-1 and Fli-1 are ETS transcription factors recurrently deregulated in mouse erythroleukemia induced by Friend viruses. Since they share the same core DNA binding site, we investigated whether they may contribute to erythroleukemia by common mechanisms. Using inducible knockdown, we demonstrated that Fli-1 contributes to proliferation, survival, and differentiation arrest of erythroleukemic cells harboring an activated fli-1 locus. Similarly, we used inducible Fli-1 knockdown and either hexamethylenebisacetamide (HMBA)- or small interfering RNA-mediated Spi-1 knockdown to investigate their respective contributions in erythroleukemic cells harboring an activated spi-1 locus. In these cells, simple or double knockdown of both Spi-1 and Fli-1 additively contributed to induce proliferation arrest and differentiation. Transcriptome profiling revealed that virtually all transcripts affected by both Fli-1 knockdown and HMBA are affected in an additive manner. Among these additively downregulated transcripts, more than 20% encode proteins involved in ribosome biogenesis, and conserved ETS binding sites are present in their gene promoters. Through chromatin immunoprecipitation, we demonstrated the association of Spi-1 and Fli-1 on these promoters in Friend erythroleukemic cells. These data lead us to propose that the oncogenicity of Spi-1, Fli-1, and possibly other ETS transcription factors may involve their ability to stimulate ribosome biogenesis.
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18
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Cui JW, Vecchiarelli-Federico LM, Li YJ, Wang GJ, Ben-David Y. Continuous Fli-1 expression plays an essential role in the proliferation and survival of F-MuLV-induced erythroleukemia and human erythroleukemia. Leukemia 2009; 23:1311-9. [PMID: 19282832 DOI: 10.1038/leu.2009.20] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Erythroleukemia induced by Friend Murine Leukemia Virus (F-MuLV) serves as a powerful tool for the study of multistage carcinogenesis and hematological malignancies in mice. Fli-1, a proto-oncogene and member of the Ets family, is activated through viral integration in F-MuLV-induced erythroleukemia, and is the most critical event in the induction of this disease. Fli-1 aberrant regulation is also observed in human malignancies, including Ewing's sarcoma, which is often linked to expression of the EWS/Fli-1 fusion oncoprotein. Here we examined the effects of Fli-1 inhibition to further elucidate its role in these pathological occurrences. The constitutive suppression of Fli-1, through RNA interference (RNAi), inhibits growth and induces death in F-MuLV-induced erythroleukemia cells. Expression of a dominant negative protein Engrailed (En)/Fli-1 reduces proliferation of EWS/Fli-1-transformed NIH-3T3 cells, and both F-MuLV-induced and human erythroleukemia cells. F-MuLV-induced erythroleukemia cells also display increased apoptosis, associated with reduced expression of bcl-2, a known fli-1 target gene. Introduction of En/Fli-1 into an F-MuLV-infected erythroblastic cell line induces differentiation, as shown by increased alpha-globin expression. These results suggest, for the first time, an essential role for continuous Fli-1 overexpression in the maintenance and survival of the malignant phenotype in murine and human erythroleukemias.
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Affiliation(s)
- J-W Cui
- Department of Molecular and Cellular Biology, Sunnybrook Health Sciences Centre, Toronto, Canada
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19
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Zhang XK, Moussa O, LaRue A, Bradshaw S, Molano I, Spyropoulos DD, Gilkeson GS, Watson DK. The transcription factor Fli-1 modulates marginal zone and follicular B cell development in mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:1644-54. [PMID: 18641300 PMCID: PMC2504761 DOI: 10.4049/jimmunol.181.3.1644] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Fli-1 belongs to the Ets transcription factor family and is expressed primarily in hematopoietic cells, including most cells active in immunity. To assess the role of Fli-1 in lymphocyte development in vivo, we generated mice that express a truncated Fli-1 protein, lacking the C-terminal transcriptional activation domain (Fli-1(DeltaCTA)). Fli-1(DeltaCTA)/Fli-1(DeltaCTA) mice had significantly fewer splenic follicular B cells, and an increased number of transitional and marginal zone B cells, compared with wild-type controls. Bone marrow reconstitution studies demonstrated that this phenotype is the result of lymphocyte intrinsic effects. Expression of Igalpha and other genes implicated in B cell development, including Pax-5, E2A, and Egr-1, are reduced, while Id1 and Id2 are increased in Fli-1(DeltaCTA)/Fli-1(DeltaCTA) mice. Proliferation of B cells from Fli-1(DeltaCTA)/Fli-1(DeltaCTA) mice was diminished, although intracellular Ca(2+) flux in B cells from Fli-1(DeltaCTA)/Fli-1(DeltaCTA) mice was similar to that of wild-type controls after anti-IgM stimulation. Immune responses and in vitro class switch recombination were also altered in Fli-1(DeltaCTA)/Fli-1(DeltaCTA) mice. Thus, Fli-1 modulates B cell development both centrally and peripherally, resulting in a significant impact on the in vivo immune response.
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Affiliation(s)
- Xian K Zhang
- Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.
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20
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Transcription factor Erg regulates angiogenesis and endothelial apoptosis through VE-cadherin. Blood 2008; 111:3498-506. [PMID: 18195090 DOI: 10.1182/blood-2007-08-105346] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Tight regulation of the balance between apoptosis and survival is essential in angiogenesis. The ETS transcription factor Erg is required for endothelial tube formation in vitro. Inhibition of Erg expression in human umbilical vein endothelial cells (HUVECs), using antisense oligonucleotides, resulted in detachment of cell-cell contacts and increased cell death. Inhibition of Erg expression by antisense in HUVECs also lowered expression of the adhesion molecule vascular endothelial (VE)-cadherin, a key regulator of endothelial intercellular junctions and survival. Using chromatin immunoprecipitation, we showed that Erg binds to the VE-cadherin promoter. Furthermore, Erg was found to enhance VE-cadherin promoter activity in a transactivation assay. Apoptosis induced by inhibition of Erg was partly rescued by overexpression of VE-cadherin-GFP, suggesting that VE-cadherin is involved in the Erg-dependent survival signals. To show the role of Erg in angiogenesis in vivo, we used siRNA against Erg in a Matrigel plug model. Erg inhibition resulted in a significant decrease in vascularization, with increase in caspase-positive endothelial cells (ECs). These results identify a new pathway regulating angiogenesis and endothelial survival, via the transcription factor Erg and the adhesion molecule VE-cadherin.
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21
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van den Akker E, Ano S, Shih HM, Wang LC, Pironin M, Palvimo JJ, Kotaja N, Kirsh O, Dejean A, Ghysdael J. FLI-1 functionally interacts with PIASxalpha, a member of the PIAS E3 SUMO ligase family. J Biol Chem 2005; 280:38035-46. [PMID: 16148010 DOI: 10.1074/jbc.m502938200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FLI-1 is a transcription factor of the ETS family that is involved in several developmental processes and that becomes oncogenic when overexpressed or mutated. As the functional regulators of FLI-1 are largely unknown, we performed a yeast two-hybrid screen with FLI-1 and identified the SUMO E3 ligase PIASxalpha/ARIP3 as a novel in vitro and in vivo binding partner of FLI-1. This interaction involved the ETS domain of FLI-1 and required the integrity of the SAP domain of PIASxalpha/ARIP3. SUMO-1 and Ubc9, the ubiquitin carrier protein component in the sumoylation pathway, were also identified as interactors of FLI-1. Both PIASxalpha/ARIP3 and the closely related PIASxbeta isoform specifically enhanced sumoylation of FLI-1 at Lys(67), located in its N-terminal activation domain. PIASxalpha/ARIP3 relocalized the normally nuclear but diffusely distributed FLI-1 protein to PIASxalpha nuclear bodies and repressed FLI-1 transcriptional activation as assessed using different ETS-binding site-dependent promoters and different cell systems. PIASxalpha repressive activity was independent of sumoylation and did not result from inhibition of FLI-1 DNA-binding activity. Analysis of the properties of a series of ARIP3 mutants showed that the repressive properties of PIASxalpha/ARIP3 require its physical interaction with FLI-1, identifying PIASxalpha as a novel corepressor of FLI-1.
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22
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Abstract
The Ets transcription factor, Fli-1, has been shown to play a pivotal role in the induction and progression of Friend Murine Leukemia Virus (F-MuLV)-induced erythroleukemia, with its overexpression leading to erythroblast survival, proliferation, and inhibition of terminal differentiation. P53 inactivation is an additional genetic alteration that occurs in late-stage leukemic progression associated with in vivo and in vitro immortalization. Since p53 protein expression levels are low, to undetectable, in primary erythroleukemic cells that express elevated levels of Fli-1, we investigated the potential regulation of p53 by Fli-1. We assessed whether the overexpression of Fli-1 could partially regulate p53 via modulation of its well-established regulator, MDM2. In this paper, we demonstrate that the promoter of MDM2 contains a consensus binding site for Fli-1 that is bound by this transcription factor in vitro and in vivo, resulting in MDM2 transcriptional regulation. We further substantiate these observations in vivo by demonstrating a positive correlation in the expression of Fli-1 and MDM2, and a negative correlation with p53 in leukemic tissues obtained from mice with Friend Disease. These observations depict a significant function of Fli-1 overexpression in the indirect control of p53, evidently capable of leading to an increasingly aggressive erythroleukemic clone in vivo.
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Affiliation(s)
- Amandine H L Truong
- Department of Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, Canada M4N 3M5
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23
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Abstract
Ets family (ETS) transcription factors, characterized by an evolutionally conserved Ets domain, play important roles in cell development, cell differentiation, cell proliferation, apoptosis and tissue remodeling. Most of them are downstream nuclear targets of Ras-MAP kinase signaling, and the deregulation of ETS genes results in the malignant transformation of cells. Several ETS genes are rearranged in human leukemia and Ewing tumors to produce chimeric oncoproteins. Furthermore, the aberrant expression of several ETS genes is often observed in various types of human malignant tumors. Considering that some ETS transcription factors are involved in malignant transformation and tumor progression, including invasion, metastasis and neo-angiogenesis through the activation of cancer-related genes, they could be potential molecular targets for selective cancer therapy.
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Affiliation(s)
- Tsuneyuki Oikawa
- Department of Cell Genetics, Sasaki Institute, Chiyoda-ku, Tokyo 101-0062, Japan.
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24
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Dazy S, Damiola F, Parisey N, Beug H, Gandrillon O. The MEK-1/ERKs signalling pathway is differentially involved in the self-renewal of early and late avian erythroid progenitor cells. Oncogene 2003; 22:9205-16. [PMID: 14681680 DOI: 10.1038/sj.onc.1207049] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Making decisions between self-renewal and differentiation is a central ability of stem cells. Elucidation of molecular networks governing this decision is therefore of prime importance. A model of choice to explore this question is represented by chicken erythroid progenitors, in which self-renewal versus differentiation as well as progenitor maturation are regulated by external factor combinations. We used this system to study whether similar or different signalling pathways were involved in the self-renewal of early, immature or more mature erythroid progenitors. We show that a transforming growth factor (TGF)-alpha-activated Ras/MEK-1/ERK1/2 pathway is strictly required for immature self-renewing cells but becomes fully dispensable when those cells are induced to differentiate. Consequently, pharmacological inhibition of this pathway led to spontaneous differentiation, only dependent on the presence of survival signals. Conversely, ectopic expression of a constitutive form of MEK-1 stimulates renewal and arrests differentiation process. Finally, we demonstrate that the ERK/MAPK signalling pathway is required in early but not in late primary erythroid progenitors, which can be turned into each other by different growth factor combinations specifically driving their renewal. To the best of our knowledge, this is the first description of a central role of ERK/MAPK signalling in regulating progenitor plasticity in the same cell type under different environmental conditions.
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Affiliation(s)
- Sébastien Dazy
- Laboratoire Signalisations et identités cellulaires, Centre de Génétique Moléculaire et Cellulaire CNRS UMR 5534, Université Claude Bernard Lyon 1, bât Grégoire Mendel, 16 rue Dubois, 69622 Villeurbanne, France
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25
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Lebigot I, Gardellin P, Lefebvre L, Beug H, Ghysdael J, Quang CT. Up-regulation of SLAP in FLI-1-transformed erythroblasts interferes with EpoR signaling. Blood 2003; 102:4555-62. [PMID: 12946994 DOI: 10.1182/blood-2003-06-2077] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rearrangement of the FLI-1 locus and ensuing overexpression of FLI-1 protein is an early event in Friend murine leukemia virus (F-MuLV)-induced erythroleukemia. When overexpressed in primary erythroblasts, FLI-1 converts erythropoietin (Epo)-induced terminal differentiation into a proliferative response. We found that SLAP, a gene encoding a recently described negative regulator of T-cell antigen receptor function during thymocyte development, is up-regulated both at the RNA and protein levels in FLI-1-transformed erythroblasts. Src-like adaptor protein (SLAP) was found in a specific complex with erythropoietin receptor (EpoR), a cytokine receptor essential to erythroid differentiation. Constitutive expression of SLAP severely impairs hemoglobinization and late survival during Epo-induced terminal differentiation of erythroblasts. This impairment is associated with the specific inhibition of several critical Epo-dependent signaling events, including signal transducer and activator of transcription 5 (STAT5) activation and up-regulation of the expression of the antiapoptotic BCL-X gene. Our data support a model by which FLI-1 inhibits normal erythroid differentiation through the deregulation of genes encoding adaptors/effectors that modify the signaling output of cytokine receptors normally required for terminal differentiation.
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Affiliation(s)
- Ingrid Lebigot
- Institut Curie, Bat 110, Centre Universitaire, 91405 Orsay, France
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26
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Ano S, Pereira R, Pironin M, Lesault I, Milley C, Lebigot I, Quang CT, Ghysdael J. Erythroblast transformation by FLI-1 depends upon its specific DNA binding and transcriptional activation properties. J Biol Chem 2003; 279:2993-3002. [PMID: 14570912 DOI: 10.1074/jbc.m303816200] [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: 12/21/2022] Open
Abstract
FLI-1 is a transcriptional regulator of the ETS family of proteins. Insertional activation at the FLI-1 locus is an early event in F-murine leukemia virus-induced erythroleukemia. Consistent with its essential role in erythroid transformation, enforced expression of FLI-1 in primary erythroblasts strongly impairs the response of these cells to erythropoietin (Epo), a cytokine essential to erythropoiesis. We show here that point mutations in the ETS domain that abolished FLI-1 binding to specific DNA elements (ETS-binding sites) suppressed the ability of FLI-1 to transform erythroblasts. The exchange of the entire ETS domain (DNA binding domain) of FLI-1 for that of PU.1 changed the DNA binding specificity of FLI-1 for that of PU.1 and impaired FLI-1 transforming properties. In contrast, ETS domain swapping mutants that maintained the DNA binding specificity of FLI-1 did not affect the ability of FLI-1 to transform erythroblasts. Deletion and swapping mutants that failed to inhibit the DNA binding activity of FLI-1 but impaired its transcriptional activation properties were also transformation-defective. Taken together, these results show that both the ability of FLI-1 to inhibit Epo-induced differentiation of erythroblasts and to confer enhanced cell survival in the absence of Epo critically depend upon FLI-1 ETS-binding site-dependent transcriptional activation properties.
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Affiliation(s)
- Sabine Ano
- CNRS UMR 146, Institut Curie, Centre Universitaire, Bâatiment 110, 91405 Orsay, France
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27
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Starck J, Cohet N, Gonnet C, Sarrazin S, Doubeikovskaia Z, Doubeikovski A, Verger A, Duterque-Coquillaud M, Morle F. Functional cross-antagonism between transcription factors FLI-1 and EKLF. Mol Cell Biol 2003; 23:1390-402. [PMID: 12556498 PMCID: PMC141137 DOI: 10.1128/mcb.23.4.1390-1402.2003] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
FLI-1 is an ETS family transcription factor which is overexpressed in Friend erythroleukemia and contributes to the blockage of differentiation of erythroleukemic cells. We show here that FLI-1 represses the transcriptional activity of the beta-globin gene promoter in MEL cells and interacts with two of its critical transactivators, GATA-1 and EKLF. Unexpectedly, FLI-1 enhances the stimulating activity of GATA-1 on a GATA-1-responsive promoter but represses that of EKLF on beta-globin and an EKLF-responsive artificial promoters. This repressive effect of FLI-1 requires the ETS DNA binding domain and its association with either the N- or C-terminal domain, which themselves interact with EKLF but not with GATA-1. Furthermore, the FLI-1 ETS domain alone behaves as an autonomous repression domain when linked to the Gal4 DNA binding domain. Taken together, these data indicate that FLI-1 represses EKLF-dependent transcription due to the repression activity of its ETS domain and its indirect recruitment to erythroid promoters by protein-protein interaction with EKLF. Reciprocally, we also show that EKLF itself represses the FLI-1-dependent megakaryocytic GPIX gene promoter, thus further suggesting that functional cross-antagonism between FLI-1 and EKLF might be involved in the control of the erythrocytic versus megakaryocytic differentiation of bipotential progenitors.
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Affiliation(s)
- Joëlle Starck
- Centre de Génétique Moléculaire et Cellulaire, CNRS UMR 5534, 69622 Villeurbanne, France
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28
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Abstract
The Ets family of transcription factors characterized by an evolutionarily-conserved DNA-binding domain regulates expression of a variety of viral and cellular genes by binding to a purine-rich GGAA/T core sequence in cooperation with other transcriptional factors and co-factors. Most Ets family proteins are nuclear targets for activation of Ras-MAP kinase signaling pathway and some of them affect proliferation of cells by regulating the immediate early response genes and other growth-related genes. Some of them also regulate apoptosis-related genes. Several Ets family proteins are preferentially expressed in specific cell lineages and are involved in their development and differentiation by increasing the enhancer or promoter activities of the genes encoding growth factor receptors and integrin families specific for the cell lineages. Many Ets family proteins also modulate gene expression through protein-protein interactions with other cellular partners. Deregulated expression or formation of chimeric fusion proteins of Ets family due to proviral insertion or chromosome translocation is associated with leukemias and specific types of solid tumors. Several Ets family proteins also participate in malignancy of tumor cells including invasion and metastasis by activating the transcription of several protease genes and angiogenesis-related genes.
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Affiliation(s)
- Tsuneyuki Oikawa
- Department of Cell Genetics, Sasaki Institute, 2-2 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
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29
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Sarrazin S, Bonod-Bidaud C, Remy P, Mehlen P, Morlé F. Caspase cleavage of the transcription factor FLI-1 during preB leukemic cell death. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1592:123-7. [PMID: 12379474 DOI: 10.1016/s0167-4889(02)00290-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Programmed cell death (apoptosis) is a complex phenomenon that is mediated in mammals mainly via the selective cleavage of intracellular proteins by the large family of cysteine aspartate protease caspases. Apoptosis is tightly regulated by the competitive effect of numerous proteins displaying either pro-apoptotic or anti-apoptotic activity. The ETS-family transcription factor FLI-1, frequently associated with malignant transformation, has been shown to display anti-apoptotic activity in several cell types including avian erythroblasts, mouse fibroblasts or lymphoid cells. We show here that apoptosis of murine preB leukemic cells is accompanied with the specific cleavage of FLI-1 by a caspase-like activity. We also demonstrate that the two isoforms of FLI-1 are indeed cleaved at three conserved sites by caspase 3 in vitro. The conservation of these cleavage sites among species suggests that the caspase cleavage of the anti-apoptotic transcription factor FLI-1 may represent a critical step to ensure irreversible cell death.
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Affiliation(s)
- Sandrine Sarrazin
- Transcription/Différenciation Hématopoïétique and Apoptose/Différenciation, label la ligue contre le cancer-Centre de Génétique Moléculaire et Cellulaire, CNRS UMR 5534, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
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Dolznig H, Habermann B, Stangl K, Deiner EM, Moriggl R, Beug H, Müllner EW. Apoptosis protection by the Epo target Bcl-X(L) allows factor-independent differentiation of primary erythroblasts. Curr Biol 2002; 12:1076-85. [PMID: 12121614 DOI: 10.1016/s0960-9822(02)00930-2] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Erythropoietin (Epo) is required for correct execution of the erythroid differentiation program. Erythropoiesis requires Bcl-X(L), a major late target of Epo-receptor signaling. Mice lacking Bcl-X(L) die around embryonic age E12.5, forming normal erythroid progenitors but lacking functional red cells. Recently, serum-free culture conditions for expansion of murine red cell progenitors were developed, yielding cells capable of in vivo-like terminal differentiation into enucleated erythrocytes, in response to Epo/insulin. Here we address whether Epo function during terminal maturation involves a cytokine-independent "default program," requiring only apoptosis inhibition through Epo-dependent upregulation of Bcl-X(L). RESULTS Exogenous expression of Bcl-X(L) or Bcl-2 in primary murine erythroblasts or clonal erythroblast lines derived from p53(-/-) mice allowed these cells to undergo terminal erythroid maturation, in the complete absence of cytokines. A potential autocrine Epo loop was ruled out by respective neutralizing antibodies. Importantly, sustained proliferation of Bcl-X(L)-expressing immature erythroblasts still required respective factors (Epo, stem cell factor [SCF], and the glucocorticoid receptor ligand dexamethasone [Dex]). Epo-independent differentiation in these Bcl-X(L)- or Bcl-2-expressing, primary erythroblasts was thus triggered by removal of the renewal factors SCF and Dex. This initiated the maturation-specific expression cascade of erythroid transcription factors, followed by differentiation divisions (characterized by a short G1 phase and decrease in cell size), hemoglobin accumulation, and enucleation. CONCLUSIONS During erythroid maturation, Epo regulates red cell numbers via apoptosis inhibition, caused by Epo-dependent upregulation of the antiapoptotic protein Bcl-X(L). This allows "default" terminal differentiation of apoptosis-protected, committed erythroblasts, independent of any exogenous signals.
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Affiliation(s)
- Helmut Dolznig
- Division of Molecular Biology, Institute of Medical Biochemistry, 1030 Vienna, Austria
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